"Vis Medicatrix Naturae"
-The Healing Power of Nature -
Modern and Traditional Approaches Towards
human Health Care
by
Nishad Jayasundara
Thesis Submitted in Completion of the- Senior Project Requirement
College of the Atlantic .., '^ ^ '<f
May, 2005 ..^ # J
/
Sfenior Project Director
Dr. Nishanta Rajakaruna
Academic Advisor
Dr. Donald c4ss
Digitized by the Internet Archive
in 2011 with funding from
Lyrasis IVIembers and Sloan Foundation
http://www.archive.org/details/vismedicatrixnatOOnish
~ Preface ~
Life has an inherent ability to maintain and restore its health. Role of a physician or
a healer is to facilitate and enhance this ability in a patient, augmenting the healing
power of nature. For thousands of years humans have taken a number of different
approaches to maintain and restore their health, from spiritual healing to stem cell
cloning. My senior project has explored two such approaches, a modern
biomedical research approach and an indigenous medical approach using
medicinal plants. Chapters One and Two describe my first-hand experiences
participating in cutting-edge biomedical research in two of the world's leading
molecular biology/biomedical research institutes. The Mount Desert Island
Biological Laboratory and The Jackson Laboratory in Bar Harbor, Maine. Chapter 3
describes my attempts to explore the role of indigenous medicine in treating
diabetes in Sri Lanka, a country with a 2500-year-old tradition of using plants to
maintain and restore human health.
~ Table of Contents -
Preface 1
Table of Contents II
Acknowledgements IV
Chapter 1 : General Introduction: Quantitative analysis of hsp70 mRNA 2
expression under salinity stress in the euryhaline shore crab
Pachygrapsus marmoratus
1.1 Abstract 03
1.2 Introduction 03
1.3 Materials and Methods 04
1.4 Results 06
1.5 Discussion 11
1.6 Conclusion 13
1 . 7 BibI iography 14
Chapter 2: General Introduction: Effect of Leprdb-SJMutatin on 17
JAK/STAT Pathway in NOD/LtJ and db 5j Mice
2.1 Introduction 18
2.2 Materials and Methods 19
2.21 Plasnnid constructions, transfections 20
and cell culture
2.22 ^-^1- leptin Binding Assay 20
2.23 Protein Extraction and Western blotting on ... 20
COS 7 cells
2.24 Protein Extraction and Western blotting on PECs 21
2.3 Results and Discussion 20
2.3 V-^l- leptin Binding Assay 21
2.32 Wetern Blot Analysis on Transfected COS 7 cells 22
2.33 Wetern Blot Analysis on Thioglycolate ... T7
Induced PECs from NOD and db 5j mice.
2 .4Conclusion 31
2.5 Bibliography 32
Chapter 3: Sri Lankan Indigenous Medicine: Diabetes as a case study
3.1 Introduction 35
3.2 History of Indigenous Medical Systems 36
3.3 Use of Pant Extracts in Modern Medicine 37
3.4 Diabetes in Allopathic Treatment 38
3.41 Insulin Injections 41
3.42 Oral Antidiabetic Drugs 44
3.5 Sri Lankan Indigenous Medical Approach to the treatment 46
of Diabetes or "Madumeha"
3.6 Plants Used Against Diabetes in Sri Lankan Indigenous 49
Medicine
3.7 Experimental methods used to investigate anti-diabetic 79
properties of traditional medicinal plants
3.8 Current Medicinal Plant Conservation Efforts in Sri Lanka 81
3.9 Conclusion 84
3.10 Bibliography 85
~ Acknowledgements ~
I must first thank my advisor Dr. Nishanta Rajakaruna for inspiring me to do this
project and providing invaluable insight and guidance. 1 would like to thank my
academic advisor, Anne Kozak, for being supportive throughout this project and
editing my thesis even at the last minute. I appreciate the freedom they have given
me to explore three distinct research projects and find a creative v^ay to
incorporate them into my Senior Project.
I must acknowledge the invaluable contributions of Dr. David Towie and Dr.
Celine Spanings-Pierott during my project at the Mount Desert Island Biological
Laboratory, ME (MDIBL). I would like to acknowledge Chris Smith and Michael
McKernan at the MDIBL and Charmantier Laboratory at the University of
Montpellier 11, France. My work at the MDIBL was supported by NSF Grant
Number IBN-0340622 to DWT.
I would like to thank Dr. Edward Leiter at the Jackson Laboratory, ME for giving me
an opportunity to carry on a research project in his lab and guiding me through it.
Many thanks to Dr. Huie-ju Pan, Darcy Darcy Pomerleau, Dr. Chul-Ho Lee for
teaching and directing my research at all times. 1 would also like to acknowledge
Jason Beckswith, Peter Ryfsnyder and Pam Stanley for their support during my time
at the Leiter Lab. My work was supported by a grant from the American Diabetes
Association and NIH grants DK36175 and DK27722 to EHL.
Without the candid contributions from Sri Lanka Ayurvedic Department, Ministry
of Indigenous Medicine, Institute of Indigenous Medicine Research Center and
Indigenous Medicine Drug Corporation the study of medicinal plants in Sri Lanka
may not be possible. I would like to give my special thanks to Dr. W. Liyanage for
introducing me to indigenous practitioners throughout the country. Also, thanks to
the support received from Dr. Dayangani Senasekara and Mr. Amarasri Dodangoda
in contacting practitioners in Sri Lanka. All their efforts have been invaluable in
completing Chapter 3 of my Senior Project.
1 am indebted to Hannah Hastings for her valuable time in helping complete this
project in a timely manner. Also, I owe much gratitude to the faculty and staff at
The College of the Atlantic for helping me with many aspects of this project.
Finally, I would like to thank my family and friends in Sri Lanka and Bar Harbor for
their continuous support and friendship.
CHAPTER 1
Quantitative analysis of hsp70 mRNA
expression under salinity stress in the
euryhaline shore crab
Pachygrapsus marmoratus
Ion regulation is one of the most important biological functions in humans and other
organisms. Severe health conditions as cystic fibrosis and heart disease result from failure
to regulate ions across the cellular membranes. Scientists have considered using marine
organisms as a model to study ion regulation, since these animals experience rapid salt
changes in their natural habitats. Pachygrapsus marmoratus (Pm) is a crustacean found
primarily along the Mediterranean coast. This species is subjected to physiological stress
due to large and rapid fluctuations in seawater salinity. Such conditions may elicit
changes in the gene expression in its gill tissue, as gills play an important role in their
osmoregulation. Along with Dr. David Towle, senior scientist at the Mount Desert Island
Biological Laboratory and Dr. Celine Spanings-Pierott, professor at University of
Montpellier II, 1 have investigated the expression of three osmoregulatory genes, Na/K
ATPase, Na/K/2C1 co-transporter and V-ATP ase, and Heat Shock Protein 70, a gene that
is responsible for refolding/repairing damaged proteins.
Through this research I hope to understand how a small crustacean such as Pm, living in
the inter-tidal zone and experiencing rapid salinity fluctuations, maintains osmotic
balance. A thorough understanding of the well-controlled osmoregulatory mechanisms of
such organisms might lead to enhance or control diseases caused by defects in ion
regulation.
The research provided with me an opportunity to understand and learn cutting-edge
molecular biology techniques and their use in modem biomedical research. I have also
had an opportunity to travel to Montpellier, France to collect fresh tissue samples of Pm
and to San Diego, CA to present my research at the Society for Integrated and
Comparative Biology Conference.
1.1 Abstract
Marbled rock crabs {Pachygrapsus marmoratus) are subjected to physiological stress due
to large and rapid fluctuations in seawater salinity. These conditions might elicit changes
in the gene expression of heat shock proteins (hsps) in gills - the most important
osmoregulatory organs. Through this study, hsp70 cDNA from Pm was sequenced and
hsp70 mRNA expression in anterior and posterior gills was quantified. Under low (10
ppt) and high (45 ppt) salinity at different time intervals, gills were extracted from Pm,
following transfer from normal seawater (32 ppt). Real-time PCR analysis showed that
hsp70 mRNA is expressed equally under control conditions in anterior (G5, G6) and
posterior (G7, G8, G9) gills. Following the transfer to low salinity, hsp70 expression
increased about 2-fold in G5, G6 and G9 at 24 and 48 h. However, in G7 and G8 it
increased by 3 to 4-fold within the first 6 h and slightly decreased by 48 h. Following
transfer to high salinity, G5, G6, and G9 did not show any significant change. However,
G8 showed a 2-fold increase within 4 h and by 48 h decreased gradually to the level
observed under control conditions. In G7, hsp70 expression increased about 3-fold within
4 h and about 4-fold in 6 h, then slightly decreased at 24 and 48 h to a level that was still
twice the amount expressed in controls. The expression of arginine kinase (AK), a
putative housekeeping gene, showed nearly equal levels at all times. These results
confirm that hsp70 is highly expressed under salinity-stressed conditions and that
posterior gills, gill 7 in particular, play an important role in osmoregulatory adjustments
of Pm.
1.2 Introduction
Organisms respond to enviroimiental conditions, such as salinity and thermal stresses
through many physiological mechanisms. These mechanisms are regulated by rapid
changes in gene expression under non-optimal conditions. Molecular responses to such
stress situations normally involve the up-regulation of one or more heat shock proteins
(Feder & Hofmann, 1999).
Heat Shock Proteins (hsp) are molecular chaperons assisting in protein refolding under
stress conditions. These proteins found in all organisms from prokaryotes to mammals
are highly conserved throughout evolution (Feder & Hofmann, 1999). Expression of hsps
under stress conditions is well-studied and documented in a number of organisms,
including marine vertebrates (Specs et al. 2002; Boutet et ai, 2003).
Marbled rock crabs {Pm) inhabit coastal regions of the Mediterranean Sea where they
may be subjected to osmotic stress due to large and rapid fluctuations in seawater
salinity. Studies have shown that the expression of genes encoding ion transport proteins
in the gills of this species is responsive to salinity change (Mouneyrac et ai, 2001).
Based on data from heat shock response to osmotic stress (Spees et ai, 2002), extremes
of salinity might also induce changes in the expression of hsps in the gills of Pm. As
noted, with differential ion transporter gene expression in gills there could be a possible
variation in hsp expression in different gills. In this study, hsp70 cDNA of Pm was
amplified and sequenced. Its expression was measured by quantitative PCR in anterior
and posterior gills which were taken from animals exposed to a time course of dilute or
concentrated seawater.
1.3 Materials and Methods
1.31 Acclimation and RNA isolation
Crabs captured on the French coast and acclimated to 32 ppt seawater were transferred to
either dilute (10 ppt) or concentrated (45 ppt) seawater. Controlled groups were
maintained in 32 ppt seawater concentration. During the transfer, care was taken to
maintain animals at natural habitat temperatures. At discrete time intervals following the
transfer, from hours to 48 hours, anterior and posterior gills (5^ gill to 9* gill [G5 to
G9]) were dissected individually. Extractions were preserved in RNA/a/er (Ambion, TX,
USA) for shipment to Maine. Total RNA was purified from all the samples using RNA
agents® Total RNA Isolation System from Promega, USA. Total RNA was analyzed for
its purification and quantified by Agilent technologies 2100 Bioanalyzer.
1.32 cDNA synthesis, PCR amplification and sequencing
Poly- A mRNA in 2ng of total RNA per sample were reverse transcribed using oligo-dT
and Superscript II reverse transcriptase (Invitrogen, NY, USA). The resulting cDNA was
used for sequencing and quantitative PCR analysis. Hsp70 cDNA was amplified using
species-specific primers based on a 600-bp hsp70 fragment serendipitously amplified
fi-om Pm in an earlier study:
Forward primer (1 13FN):
5 '-TATTGACCTGGGAACCACCTAC-3 '
Reverse primer (486RN):
5 '-CTTCGGCAGTCTCCTTCAATCTT-3 '
Amplification products were gel-purified and tested for molecular size. The gel bands
were excised, purified, and extracted using the MinElute gel extraction protocol (Sigma-
Aldrich, CA, USA). Purified products were sequenced by ABI Prism 3100 automated
sequencer at the Marine DNA Sequencing Facility at the Mount Desert Island Biological
Laboratory. Partial DNA sequences were edited and analyzed using Chromas software
and confirmed by BLAST analysis. The complete hsp70 cDNA was obtained by 3'-
RACE (Invitrogen, NY, USA) and 5 '-RACE (Clontech, NJ, USA), using primer walking
as required.
1.33 Real Time Quantitative PCR Analysis (RT-QPCR)
Species-specific 1 13FN and 486RN primers and real-time quantitative PCR with SYBR
green were used to measure the relative expression of hsp70 wRNA using the Stratagene
MX4000 Multiplex Quantitative PCR System. Triplicate samples of cDNA prepared
from equivalent of 0.1 micro gram of total RNA were used in RT-QPCR runs. Two sets
of RT-QPCRs were run to compare the /wRNA expression in samples following transfer
from 32 ppt seawater to either 10 ppt or 45 ppt seawater. The relative abundance of hsp70
wRNA in test samples were compared to samples obtained from control animals.
1.4 Results
The Bioanalyzer revealed three closely-spaced peaks of rRNA (Fig. 1.1), the crustacean
28S rRNA fragmenting to two smaller products, one or both of which may overlap the
18S rRNA peak (Skinner, 1968).
io-
j
1
9-
-
8-
\
7-
1
op
:
:
2
:
/
-1
E
l^y\^^_____y^
CO
L-^-^-^
O ~
^^
1 1 1 iT r^ 1 1 1 1 1 1
1 1 1
\
1 T 1 1 1
34 39 -44 49 54
"Time (seconds)
Fig. 1.1: Electropherogram of total RNA isolated from gill tissue
of the crab Pm, obtained by microfluidics electrophoresis with an
Agilent Bioanalyzer.
Gel electrophoresis of the PCR products using primers showed bands as estimated.
Nucleotide sequence obtained from excising and purifying the bands produced a 2,189-bp
cDNA encoding a 650-amino-acid protein {Fig. 1.2). Once assembled, the full sequence
showed high homology to proteins identified as hsp70 in other arthropods as Litopenaeus
vannamei (Ace. No. AAT46566), Penaeus monodon (Ace. No. AAQ05768),
Macrobrachium rosenbergii (Ace. No. AAS45710), and Apis mellifera (Ace. No.
XP_392933) {Fig. 1.3).
atggcaaaggcacctgctgtcggtattgatctgggaaccacctactcctgcgtgggt
MAKAPAVGIDLGTTYSCVG
gtgttccagcatggcaaggtggagatcatcgccaacgaccagggcaaccgcaccacgccc
VFQHGKVEIIANDQGNRTTP
tcctacgtcgccttcacagacacagagcgtctgattggtgacgccgccaagaaccaggtg
SYVAFTDTERLIGDAAKNQV
gcgatgaaccccaacaacactgtattcgatgccaagcgactgatcggccgcaaattcgaa
AMNPNNTVFDAKRLIGRKFE
gaccacacagtccagagcgacatgaagcattggcccttcaccatcatcaacgagagcaca
DHTVQSDMKHWPFTIINEST
aagccaaagatccaggtggagtacaagggagacaagaagaccttctaccccgaggagatc
KPKIQVEYKGDKKTFYPEEI
tcctcgatggtgctcatcaaaatgaaggagaccgctgaggcttacctgggatccacagtg
SSMVLIKMKETAEAYLGSTV
aaggatgctgtagtcactgtgcctgcctacttcaacgattctcagcgtcaggccaccaag
KDAVVTVPAYFNDSQRQATK
gacgctggaaccatctcgggtctgaatgtgctgcgtatcattaacgaacctaccgctgct
DAGTISGLNVLRIINEPTAA
gccatcgcctacggcctcgacaagaaggttggcggtgagcgcaacgtcttgatcttcgat
AIAYGLDKKVGGERNVLI FD
cttggcggcggtaccttcgatgtgtccatccttaccatcgaggatggcatcttcgaggtc
LGGGTFDVSILTIEDGIFEV
aagtcaacagctggtgacactcacttgggcggtgaagacttcgacaaccgtatggtgaac
KSTAGDTHLGGEDFDNRMVN
cacttcatccaggaattcaagcgcaagtacaagaaggacccaagtgagaacaagcgctcc
HFIQEFKRKYKKDPSENKRS
ctgcgtcgcctgcgtactgcctgtgagcgtgcgaagcgtaccctgtcttcctcgacacag
LRRLRTACERAKRTLSSSTQ
gccagcgtggagatcgactccctcttcgaaggtatcgatttctacacctccatcacccgt
ASVEIDSLFEGIDFYTSITR
gctcgcttcgaggagctgtgcgccgatctgttccgtggcaccttggagcccgtggagaag
ARFEELCADLFRGTLEPVEK
tccctccgtgatgcgaagatggacaaggcccagatccacgacatcgtccttgtcggagga
SLRDAKMDKAQIHDIVLVGG
tccacccgtatccccaagatccagaagctcctccaggacttcttcaacggcaaggagctg
STRIPKIQKLLQDFFNGKEL
aacaagtccatcaaccccgatgaggctgtggcctacggtgccgccgtccaggccgccatc
NKS INPDEAVAYGAAVQAAI
ttgtgtggtgacaagtccgaggctgtgcaggacctgttgctgttggacgtgacccccttg
LCGDKSEAVQDLLLLDVTPL
tccctgggtatcgagactgccggtggtgtgatgaccgctctcatcaagcgtaacaccacc
SLGIETAGGVMTALIKRNTT
atccccaccaagcagactcagaccttcaccacctactctgacaaccagccaggtgtgctc
IPTKQTQTFTTYSDNQPGVL
atccaggtgtacgagggagagcgtgccatgaccaaggacaacaacctcctgggtaagttc
IQVYEGERAMTKDNNLLGKF
gagctgagtggcatcccacctgctcctcgtggcgtgcctcagatcgaggtcaccttcgac
ELSGIPPAPRGVPQIEVTFD
attgacgccaacggcatcctgaacgtatccgccgtggacaagtctaccggcaaggagaac
IDANGILNVSAVDKSTGKEN
aagattaccatcaccaacgacaagggtcgcctctccaaggaggagatcgagcgcatggtg
KITITNDKGRLSKEEIERMV
caggacgccgagaagtacaaggctgacgatgagaagcagagggaccgtatttctgccaag
QDAEKYKADDEKQRDRISAK
aactccctggagtcttactgcttcaacatgaagtcaacagttgaggacgagaagttcaag
NSLESYCFNMKSTVEDEKFK
gagaagatttctgaagaggaccgcaacaagattttggagacctgcaacgagactatcaag
EKISEEDRNKILETCNETIK
tggctggacatgaaccagctgggcgagaaggaagagtatgagcacaagcagaaggagatc
WLDMNQLGEKEEYEHKQKEI
gagcaggtgtgcaaccccatcattaccaagatgtatgctgctgctggtggtgctcctcca
EQVCNPIITKMYAAAGGAPP
ggtggcatgcccggcggcttcccaggtggtgccccaggtgccggcggtgctgctcccggt
GGMPGGFPGGAPGAGGAAPG
gctggtggttcctccggacccaccatcgaggaggtcgattaa
AGGSSGPTIEEVD-
Fig. 7. 2;. Amplified Nucleotide sequence from the PCR
product and the Amino Acid sequence for hsp70 in Pm.
Pac hyg rap sua
Lit ope nae us
Pen aeu s
Mac rob rac hit
Pac hyg rap s
Li t ope nae \
Mac rob rac hit
Apis
140
VL. KMK ETA EAjJlG ;
1 60 *
leo
SQR QAT KDA GTI SGL n: L RI I NEP TAA -,
SQR QAT KDA GT I SGL N 'L R 1 1 N!
HsKfenys
SQRQATKDAGTI SGLN^LRHNI
:pt
AA \
SQRQATKDAGTI SGI.N' LRIINI
:pt
jM
Pac hyg rap
Lit ope
Pen
Mac rob rac hi
Pac hyg rap sus
Li t ope nae us
Pen aeu 3
Mac rob rac hii:
Apis
:, CgD LFR GTL El . — _-,
j C!?D LFR GTL EPVEK^jiLRD
._._ VLVGGSTRIPKIQKLLQDFl
KA QIH DIVLVG GST RIP KIQ KLL QDF FNG K
Pac hyg rap su
Li t ope nae us
Pen aeu s
Mac rob rac hi
Apis
! inpdeaval, gaavqaail igdkse :
! inpdeavaggaavqaail" ^
; inpdeavap;gaavqaail
jjMI
^mSSS
^iii
m
mss
Mt
m
Pac hyg rap
Li t ope
Pen
Mac rob rac hi
Pac hyg rap
Li t ope
Pen aeu s
Mac rob rac hi
Ap
Fig. 13: Multiple alignment of hsp70 amino acid sequences from four crustacean species and
honeybee. Pachygrapsus marmoratus (present study), Litopenaeiis vanname (Ace. No.
AAT46566), Penaeus monodon (Ace. No. AAQ05768), Macrobrachium rosenbergii (Ace. No.
AAS45710), and Apis rnellifera (Ace. No. XP_392933).
Relative expression levels of hsp70 wRNA were measured in the 5 to 9 gill (from
anterior to posterior) of P. marmoratus in samples taken from dilute and concentrated sea
water at each time interval. Hsp70 expression was evident in all the samples including the
control. Amplification of a dilution series prepared from the most posterior gill (G9)
produced a standard curve {Fig. 1.4) that was employed in analyzing relative transcript
abundance in other gills. The relative abundance of hsp70 wRNA in test samples were
compared to samples obtained from control animals.
Fig. 1.4: Real-time PCR amplfication of hsp70 in a reference
cDNA prepared from Pm gill diluted to give the equivalent of 1,
0.1, 0.01, and 0.001 J (left to right) of the cDNA preparation (1
1 cDNA = 0. 1 _g total RNA). Fluorescence is plotted as a
function of cycle number. Inset: Standard curve derived by
plotting threshold cycle (Ct) as a function of cDNA volume.
Dissociation of the final amplification product revealed a single major meltinj
temperature signifying the predominance of a single hsp70 sequence (Fig. 1.4).
54 H M eo ei e4
S3 S2 54
Fig. 1.5: Second derivative of the thermal dissociation curve
of the hsp70 amplification product obtained by real-time
PCR of cDNA from Pm, plotted as a function of temperature.
The hsp70 transcript abundance in individual gills of Pm at intervals following transfer
from normal sea water to diluted and concentrated sea water were calculated and plotted
as a function of time (Figl. 6A & 1.6B).
10
Hours In 10 ppt
G7
Gill number
Hours in 45 ppt
Fig. 1.6: Relative mRNA expression of hsp70, determined by quantitative PCR, in gills of
Pm pooled from at least three animals per sampling interval, in relation to gill 9 after 48
hours of exposure of crabs to 10 ppt and 45 ppt seaw^ater.
1.5 Discussion
Control experiments showed that the wRNA expression of arginine kinase (AK) - a
putative housekeeping gene (Kotlyar et al. 2000) - was at nearly equal levels at all times
under similar stress conditions (Fig. 1.7). Moreover, hsp70 mRNA was expressed equally
under control conditions (zero time) in anterior (G5, G6) and posterior (G7, G8, G9) gills.
It is known that measurable levels of hsp70 are not unusual in most organisms under
unstressed conditions (Helmuth & Hofmann, 2001; Halpin et al., 2002). Following
transfer to low salinity, hsp70 mRNA expression increased in all gills {Fig. 1.2A). The
degree of increase was about 2-fold in G5, G6 and G9 at 24 and 48 h. However, in G7
and G8 hsp70 mRNA s increased by 3 to 4-fold within the first 6 h then slightly
decreased by 48 h.
11
Gilt Number
Fig. 1.7: Relative mRNA expression of Argenine Kinase,
determined by quantitative PCR, in gills of Pm pooled
from at least three animals per sampling interval, in
relation to gill 9 after 48 hours of exposure of crabs to 10
ppt seawater. AK is equally expresses in each gill except
for at 48 h.
Following transfer to high salinity, G5, G6, and G9 did not show any significant change
in hsp70 mRNA throughout the study period. However, G8 showed a 2-fold increase
within 4 h and by 48 h decreased gradually to the level observed under control
conditions. In G7, hsp70 mRNA expression increased about 3-fold within 4 h and about
4-fold in 6 h, then slightly decreased at 24 and 48 h to a level that was still twice the
amount expressed in controls.
In the lower salinity, Pm effectively hyper-osmoregulates its hemolymph via increased
ion uptake across the gills, mediated at least in part by induction of ion transporter gene
transcription. In high salinity the crab is a hypo-osmoregulator, most likely by enhanced
salt excretion across the gills (Pierrot, et al. 1995; Pierrot, et al. 2000).
12
The data, coupled with our observation of a dramatic induction of ion transporter gene
expression in G7 under similar conditions (Eckhardt et al., 1995; Spanings-Pierrot &
Towle, 2003) suggests that G7 plays an important role in the response to hypersaline
conditions and G7 may indeed be primarily responsible for ion exchange during
hyperosmotic stress. The results also implies that osmotic stress may lead to enhanced
hsp70 expression in all gills, with a more rapid response in the two posterior gills that are
believed to be most involved in ion uptake (Berlind & Kamemoto, 1977; Spanings-
Pierrot & Towle, 2004). This data also confirms that hsps are not only expressed under
thermal stress conditions (Somero, 1995; Frankenberg et al., 2000,; Halpin, et al., 2002),
but play a vital role in organisms' ability to adapt to rapid salinity level changes in their
envirormient.
1.6 Conclusions
Individual gills may be functionally distinct, particularly regarding osmoregulatory and
stress-related responses to concentrated seawater and diluted seawater. RT-QPCR data
confirms the induction of expression in hspTO gene under stress conditions and suggests
the importance of it in adaptive responses of organisms. Highly homologous sequence of
hsp70 gene in Pachygrapsus marmoratus to other organisms provides evidence for the
conserved hsp genes throughout evolution.
13
1.7 Bibliography
Berlind, A. and Kamemoto, F. I. 1977. Rapid water permeability changes in eyestalkless
euryhaline crabs and in isolated, perfused gills. Comp. Biochem. Physiol. 58A: 383-385.
Boutet, I., Tanguy, A., Rousseau, S., Auffret, M. and Moraga, D., 2003. Molecular
identification and expression of heat shock cognate 70 (hsc70) and heat shock protein 70
(hsp70) genes in the Pacific oyster Crassostrea gigas. Cell Stress Chaperones 8: 76- 85.
Eckhardt, E., Pierrot, C, Thuet, P., Van Herp, F., Charmantier Daures, M., Trilles, J.-P.,
and Charmantier, G. 1995. Stimulation of osmoregulating processes in the perfused gill
of the crab Pachygrapsm marmoratus (Crustacea, Decapoda) by a sinus gland peptide.
Gen. Comp. Endocrinol. 99: 169-177.
Frankenberg, M.M., Jackson, S.A. and Clegg, J.S. 2000. The heat shock response of adult
Artemiafranciscana. J. Therm. Biol. 25: 481^90.
Feder, M.E. and Hofmann, G.E., 1999. Heat-shock proteins, molecular chaperones, and
the stress response: evolutionary and ecological physiology. Annu. Rev. Physiol. 61,
243- 282.
Halpin, P.M., Sorte, C.J., Hofmann, G.E. and Menge, B.A., 2002. Patterns of variation in
levels of hsp70 in natural rocky shore populations from microscales to mesoscales.
Integr. Comp. Biol. 42: 815- 824.
Helmuth, B.S.T. and Hofmann, G.E., 2001. Microhabitats, thermal heterogeneity, and
patterns of physiological stress in the rocky intertidal zone. Biol. Bull. 201: 374- 384.
Kotlyar, S., Weihrauch, D., Paulsen, RS., and Towle, DW. 2000. Expression of arginine
kinase enzymatic activity and mRNA in gills of the euryhaline crabs Carcinus maenas
and Callinectes sapidus J. Exp. Bio. 203: 2395-2404
Mouneyrac C, Amiard-Triquet C, Amiard J.C. and Rainbow PS. 2001. Comparison of
metallothionein concentrations and tissue distribution of trace metals in crabs
(Pachygrapsus marmoratus) from a metal-rich estuary, in and out of the reproductive
season. Comp. Biochem. Physiol. C. Toxicol. Pharmacol. 129:193-209.
Pierrot, C, Pequeux, A. and Thuet, P. 1995. Perfusion of gills isolated from the hyper-
hyporegulating crab Pachygrapsus marmoratus (Crustacea, decapoda): adaptation of a
method. Arch. Physiol. Biochem. 103:401-409.
Spanings-Pierrot, C, Soyez, D., Van Herp, F., Gompel, M., Skaret, G., Grousset, E., and
Charmantier, G. 2000 Involvement of Crustacean Hyperglycemic Hormone in the control
14
of gill ion transport in the crab Pachygrapsus marmoratus. Gen. Comp. Endocrinol. 1 19:
340-350
Skinner, D.M., 1968. Isolation and characterization of ribosomal ribonucleic acid from
the crustacean, Gecarcinus lateralis. J. Exp. Zool. 169: 347- 356.
Somero, G.N., 1995. Proteins and temperature. Annu. Rev. Physiol. 57: 43-68.
Spanings-Pierrot, C, and D.W. Towle. 2003. Expression of Na^,K*-ATPase mRNA in
gills of the euryhaline crab Pachygrapsus marmoratus adapted to low and high salinity.
Bulletin MDIBL 42: 44-46.
Spanings-Pierrot, C, and D.W. Towle. 2004.Salinity-related expression of the
Na*/K72Cr cotransporter and V-type ff-ATPase in gills of the euryhaline crab
Pachygrapsus marmoratus. Bulletin MDIBL 43: 6-8.
Specs, J.L., Chang, S.A., Snyder, M.J., and Chang, E.S. 2002. Osmotic induction of
stress-responsive gene expression in the lobster Homarus americanus. Biol. Bull. 203:
331-337.
Voznesensky, M., Lenz, P.H., Spanings-Pierrot, C, and Towle, D.W. 2004.Genomic
approaches to detecting thermal stress in Calanus finmarchicus (Copepoda: Calanoida).
J. Exp. Mar. Biol. Eco. 311: 37-46
15
CHAPTER 2
Effect of Leprdb-SJMutatin on
JAK/STAT Pathway in
NOD/LtJ and db 5j Mice
Diabetes is one of the most common and severe health conditions throughout the world.
Although diabetes is a widespread disease affecting people of all ages, gender or
ethnicity, a permanent cure is yet to be discovered. There are two common types of
diabetes, type 1 and type 2 (TID & T2D). Investigators have been using mouse models to
test causes and effects of these types of diabetes for many years. With the advent of
modem molecular biology techniques, diabetic research has taken a new direction, even
the use of stem cells to cure diabetes is now a possibility.
For the past two decades Dr. Edward Leiter and his research group at the Jackson
Laboratory, ME, have focused on understanding the immune responses involved in TID.
Recent studies suggesting leptin - originally characterized as a hormone governing
satiety, hunger and body fat metabolism - is stimulating a certain type of immune
responses have brought new direction to Dr. Leiters' research group. Dr. Leiter and
colleagues hypothesized that by limiting leptin activity through its receptor might provide
a novel method of down-regulating these immune responses.
I joined Dr Leiter' s research group in Fall 2004 and have been working under the
supervision of Dr. Huie-Ju Pan, Ms. Darcy Pomerleau and Dr. Chul-Ho Lee. My focus
was to investigate the leptin response in the mutated and wild type mice to induce a
certain biochemical pathway and to support the hypothesis of using the mutated mouse
strain as a novel model to study leptin-mediated immune responses. My results indicate
that manipulation of the leptin/leptin receptor axis may provide a novel means of down-
regulating autoimmunity in TID and confirm a role for leptin as a mediator in the
development of this disease in wild type mice.
Through this experience, I have gained a thorough understanding of certain molecular
biological techniques used in current biomedical research with direct applications
towards human health care.
17
2.1 Introduction
Type I diabetes (TID), also known as insulin-dependent diabetes mellitus, is
characterized as an immunologically-mediated disease under endocrine control. In TID
patients, the autoimmune destruction of pancreatic beta cells results in insulin deficiency
and hyperglycemia (Soria et al, 2001). Immune responses in TID are thoroughly studied
using Non Obese Diabetic (NOD) mouse strain as a model (Serreze & Leiter 2001).
However, there has been little research done on its endocrine system of this mouse strain
(Homo-Delarche, 2004).
Leptin is 16-kDa protein secreted by adipose tissues. It is a member of the helicale
cytokines family and has a structure similar to IL-2 (Interleukin 2) (Baumann, et al.,
1996). Leptin receptor (LR), a class I cytokine family receptor, due to alternative splicing
has at least six isoforms with a common extra cellular domain (Tartaglia, 1997). Leptin
binding to its' receptor elicits receptor dimerization and initiates accumulation and
autophosphorylation of Janus Kinases (JAK 1 and JAK 2). This in turn acts as a docking
site for phosphorylation of STATs (Signal Transducer and Activator of Transcription), in
particular STAT 3 and STAT 5. STATs translocate to the nucleus and induce the
expression of other genes, including negative regulators, such as suppressor of cytokine
signaling 3 (S0CS3) (Bjorbaek et al, 1999) and the protein tyrosine phosphatase IB
(Cheng e^ a/., 2002).
Leptin's functional receptor isoform (Rb) is present in the hypothalamus where it
regulates energy metabolism and neuroendocrine function (Lord et al, 1998). It is
studied mostly for its association with regulation of energy metabolism, feeding behavior
(Friedman, 1998), reproduction (Chehab et a/., 1996), and other biological functions. In
recent studies the leptin receptor was also identified in immune cells of both humans and
animals (Lord et al, 1998). This suggests that leptin could be an immunomodulatory
molecule. For example, leptin promotes the proliferation and secretion of IL-2 by naive
CD4+ T cells, but not memory T cells in both humans and mice (Lord et al, 1998, La
Cava & Matarese, 2004). Conversely, when human memory T cells were examined.
leptin was observed to inhibit IL-2 and IL-4 production while stimulating the secretion of
IFN (Lord et al., 2000). Based on these results, limiting Leptin signals through its
receptor might provide a novel means of downregulating a T helper- 1 (Thl)-biased
immune response, hence delay the onset of autoimmune response causing TID.
Supporting this hypothesis, postnatal administration of recombinant leptin precipitated
early TID onset (by 7 weeks of age) in -85% of treated NOD female mice (Matarese et
al, 2002).
An unexpectedly produced point mutation on the extra cellular domain of NOD leptin
receptor (designated Leprdbsj) has produced a way of limiting leptin signaling through it
receptor. This strain has a very different phenotypic effect on the course of autoimmune
diabetes development. NOD/LtJ mice of both sexes coisogenic for the Leprdbsj mutation
developed juvenile obesity and type 2 diabetes (T2D) within two wk of weaning. Our
research group has hypothesized that the mutation may have changed the receptor
structure causing inhibition or reduction of leptin binding. Even if leptin is binding, it is
possible that mutation may have an effect on the intracellular activity - JAK/STAT
phosphorylation - of the receptor. Thus, the research described in this study aims to
investigate:
1. the '^^I-Leptin binding to short and long forms of wild type and mutated leptin
receptor in COS 7 cells.
2. the expression of short and long forms of lepin receptor
3. the phosphorylation of JAK 2 and STAT 3 in transfected COS 7 cells and
peritoneal exudate cells from wild type and mutated mice.
2.2 Materials and Methods
Invitro (using COS 7 cells - Green Monkey Liver cells) and Invivo (using Peritoneal
Exudate Cells -PEC) studies were conducted to investigate the effects of the Leprab-sj
mutation on leptin binding and downstream regulatory pathways. Experiments were
designed to investigate the activity of wild type and mutated short form (Ra) and the long
fonn/functional form (Rb) of the leptin receptor.
19
2.21 Plasmid constructions, transfect ions and cell culture.
Wild-type and mutated Ra and Rb DNA were inserted in the BMHl site of a
pcDNA3/CMV vector (Invitrogen, NY, USA) containing a modified polylinker. COS-7
cells) were grown in DMEM (Hyclone Dulbecco's Modified Eagle Medium)
supplemented with 10% (v/v) FBS, 0.1 mg/ml streptomycin, (all from Life Technologies,
Gaithersburg, MD). Transient transfections were performed using Lipid (invitrogen
lipofectamine cat 18324-012) according to manufactuer's instructions.
2.22 '^^I- leptin Binding Assay
Radioligand binding experiments were performed on COS 7 cells 48 h post transfection
with Wild type (NOD) and mutated (db) DNA constructs. Cells plated in 6-well plates
were washed twice with ice-cold PBS and incubated in binding buffer (DMEM, 1%
BSA) containing 10^ cpm/well of '^^1-leptin (PerkinElmer life sciences, USA) in the
absence or presence of 200 nM of cold leptin (PerroTech Inc, USA) for 4 h at 4°C. Cells
were washed twice with ice-cold PBS, lysed in IN NaOH and the radioactivity was
measured in a -counter. To determine the binding affinity, COS 7 cells (48 h post
transfecction) were incubated for 4 h at 4°C with '^^1-leptin and varying concentrations of
(0, lO'^- 10"^M) unlabeled human leptin.
2.23 Protein Extraction and Western blotting on COS 7 cells
COS 7 cells were transfected with NOD and db DNA constructs in duplicates. Forty-
eight h post transfection, Zeosin (200 fil of Zeosin, DMEM, 10% FBS, 1% Pen-Strep)
was added to COS 7 cells for selection of transfected vs non-trasnfected cells. One set of
the selected cells was treated with 1 |ag/ml cold leptin (PerroTech Inc, USA), while the
other set was left untreated. After 15 min at 37*^0, both sets of cells were homogenized in
500 \i\ RIPA lysis buffer (50 mM Tris, pH 7.4; 1% Nonidet P-40; 150 mM NaCl; 1 mM
EDTA; 1 mM phenylmethylsulfonyl fluoride, 1 ^g/ml aprotinin, 1 |ig/ml leupeptin, 1
mM Na3V04, 1 mM NaF) and proteins were extracted using a 28G injecting needle.
Protein concentrations were measured using a protein assay (Bradford protein assay, Bio-
Rad, Hercules, CA, USA). Seventy five micrograms of protein ly sates with beta-
20
mercaptoethanol and a sample buffer were loaded onto polyacrylamide gels (Criterion,
6% gradient Tris-HCl; Bio-Rad). Cells were then transfered onto nitrocellulose
membranes (Protran, Schleicher & Schuell, Keene, NH, USA) using transfer buffer (50
mM Tris, 20 mM glycine, 20% methanol). Membranes were blocked with 5% nonfat
dried milk (20 mM Tris, pH 7.4; 0.9% NaCl; 0.05% Tween 20) and incubated with an
anti-leptin receptor (1:2000, Upstate Reagents), anti-P-JAK2 (1:500) (Upstate Reagents)
and anti-P-STAT 3 antibody (1:1000) overnight at 4° C. Membranes were then washed
(TEST) and incubated with secondary antibodies (antirabbit-, 1:10,000; Bio-Rad),
washed and developed by enhanced chemiluminescence (ECLplus, Amersham, NJ, USA)
and x-ray films (Amersham). The developed images were scanned with Fuji Image
Viewer and the band intensity was measured for each well.
2.24 Protein Extraction and Western blotting on PECs
NOD and db5j male mice (of 7 weeks age) were injected with thioglycolate to induce
peritoneal macrophages. Four days post injection, PECs were collected from the mice in
Hanks buffer (25mM HEPES/0.1 mg/ml DNase/HBSS). Cells were counted using a
coulter counter, and an equal number of duplicates from each cell type (NODs and db5js)
were plated in 10cm dishes. After serum starvation overnight, one set of cells were
treated with cold leptin for 15 mins at 37°C. To investigate the expression of leptin
receptor, P-JAK2 and P-STAT 3 same Western Blot analysis as mentioned above was
used.
2.3 Results and Discussion
2.31 /- leptin Binding Assay
CPM counts obtained from the -counter were plotted against a concentration gradient of
cold leptin for each type of DNA construct. In general wild type leptin receptor showed a
higher binding affinity than the mutated form. Wild type short form had a higher binding
affinity than the long form as expected. Similar pattern was observed in mutated short
form and long form (Fig. 1.1).
21
This data suggests that the mutated form of leptin receptor has an adverse effect on leptin
binding which affects the downstream activity of leptin receptor. The long form of leptin
also has a lower binding affinity than the shorter form. Although there is less binding in
the long/functional form, it has been found to activate downstream JAK/STAT pathway
(Tartaglia, 1997). Thus, less binding affinity of leptin to its mutated receptor may not
affect the JAK/STAT phosphorylation. Lack of leptin activity efficiency due to low
binding may well lead to delays in transduction and activation of transcription factors
responsible for immune responses, possibly delaying the onset of TID.
Leptin Binding
Wt Ra
Wt Rb
db Ra
db Rb
0.0005 0.001 0.005 0.01
Leptin Cono: ug/ml
Fig. 1.1: Binding of '"l-leptm to transfected COS 7 cells with NOD Ra & Rb and db Ra
& Rb DNA constructs. CPM Counts from the gama-counter are plotted as a function of
added cold leptin concentration gradient in each plate.
2.32 Wetern Blot Analysis on Transfected COS 7 cells.
According to the intensity of the band obtained from the Western Blot, the expression
levels of leptin receptor after transfection was determined. The primary antibody used
was a nonspecific antibody to both forms of LR. Resuhs show that it identifies the long
form of the receptor, but not the short form (Fig. 2. 2 A & 2.2BJ.
22
Leptin Receptor expression
50 1
45
40
|35
« 30
I20.
X
"" 10 -
5 -
-
i 1
n 1 — 1
Control
WT Ra db Ra WT Rb db Rb
Receptor type
Fig. 2. 2 A
Fig. 2.2B
Fig 2.2: The control is non transfected COS 7 cells, Ra and Rb are short and long
forms and WT is wild type and db is mutated forms. 2.2A\ Expression of leptin
receptor - pointed with the arrow compliments with the predicted size of the long
form of the receptor. Short form is not identified. 2.2B : Expression levels
determined from the band intensity for each DNA construct.
Results confirm that the transfection was successful and the receptor was expressed in
COS 7 cells. Multiple experiments were carried with varying conditions to obtain a band
expressing the short form, but ended unsuccessfully.
Data obtained for expression of phosphorylation of JAK 2 and STAT 3 pathways in
transfected COS 7 cells suggests that the Leprdb-sj mutation has an adverse effect on the
leptin activity.
23
Fig. 2. 3 A
Fig.2.3B
Fig. 2. 3 A : Phosphorylated JAK 2 expression in protein iysates from Control (non
transfected COS 7 cells), WT Ra, WT Rb, db Ra, db Rb. (+) signs indicate that they were
treated with leptin. (-) signs indicate untreated cells. Pointed by the arrow is the
complementary size for a phosphorylated JAK 2 band. The Antibody used was anti-
phospho-JAK2. Fig. 2.3B: Intensity of the bands was measured for each type of cells. (+)
and (-) signs indicates leptin treated and untreated cells respectively.
This data implies that the long form of leptin (Rb) is a better active site than the short
form. As expected, cells transfected with DNA constructs have a significant difference in
24
JAK 2 phosphorylation compared to the controls. In WT Rb, addition of leptin lowered
the expression of P- JAK 2 (Phosphorylated JAK 2) by three fold as opposed to those left
untreated. WT Rb+ also had a 2 fold decrease of P- JAK 2 compared to dbRb+. WT Ra
had almost no P-JAK 2, while db Ra+ had a higher expression of P-JAK 2 but less than
the long forms (Fig.2. 3 A &2. 3B)
STAT 3 was phosphorylated in all of the cell types. It is evident that there is another
mechanism than leptin receptor that activates JAK/STAT pathways, as there is
phosphorylation of STAT 3 in the control cells. However, this mechanism has is affected
by the insertion of the leptin receptor. The short form of the leptin receptor does not have
a STAT phosphorylation site (Uotani et al, 1999). Rather, the expression levels seen
under WT Ra and db Ra seems to be due to another mechanism of STAT activation. As
expected, the long form has a high expression of STAT 3 phosphorylation. In particular,
the addition of leptin has increased the expression level in both WT Rb and db Rb.
However, compared to the mutated form, the wild type has a low level of phosphoryated
STAT 3. (Fig. 2.4A & 2. 4B)
C+ C- WTRa dbRa WT Rb db Rb
+ - + - + - + -
Fig. 2.4 A.
25
Phosphorylated STAT 3 expression
20
18
15
14
12 ^
10
8
6
4
2
■
r-
n,n
■
—
r-
-1
-^
.(^^ >' <j?>'' ,0^ <}3>'' <i> .<p'' ^ <}p'' ^
Leptin Receptor type
Fig. 2.4.B.
Fig 2. 4 A : Phosphorylated STATS expression in protein lysates from Control (non
transfected COS 7 cells), WT Ra, WT Rb, db Ra, db Rb. (+) signs indicate that the
samples were treated with leptin. (-) signs indicate untreated cells. Pointed by the arrow is
the complementary size for a phosphorylated STATS band. The antibody used was anti-
phospho-STAT S. Fig 2.4B: Intensity of the bands were measured for each type of cells.
(+) and (-) signs indicate leptin treated and untreated cells respectively.
The invitro experiments were carried out solely to confirm the differences of leptin action
between the mutated and wild type long and short forms. Data obtained for
phosphorylation of JAK and STAT S in transfected COS 7 cells are not conclusive for the
leptin activity in NOD and db 5j mice. Cellular responses to the environment depend on
the whole genome of the cell. Difference in the genetic makeup of COS 7 cells and NOD
or db5j mice PECs might elicit a different response to leptin and in the downstream
regulation of leptin receptor.
26
2. S3 Wetern Blot Analysis on Thioglycolate Induced PECs from NOD and db 5j mice.
The data confirmed the previous Northern Blot resuhs (unpublished data) suggesting the
expression of leptin receptor long form in PECs. Both, NOD and db 5j had similar
expression levels of the long form {Fig. 2.5A & 2.5B). The antibody used did not
recognize the short form of the leptin receptor, though its expression at wRNA level is
confirmed by previous Northern Blot data.
Fig 2. 5 A
Leptin Receptor expression
800000-
700000-
600000
500000
<
400000
300000
200000
100000-
1
NOD NOO dbSj db5j+
Fig 2. 5 B
Fig. 2. 5 A: leptin receptor expression in PECs from wild type and
db 5j mice. NOD+ and db 5j + were treated with cold leptin for
15 mins. Size of the band was the expected size for long form of
leptin receptor. Antibody used did not recognize the short form.
Fig. 2.5B: Measured band intensity for each sample. Long form
leptin receptor is expressed equally.
27
Phosphorylated JAK 2 expression in PECs was leptin dependant, leptin treated NOD
(NOD+) had no expression of P-JAK 2 and db 5j+ had a significantly decreased amount
of P-JAk2 expressed compared to the untreated sample. Untreated db 5j had a high
phosphorylation of JAK 2, but considerably lower than that of untreated NOD (Fig 2.6A
&2.6B).
Fig..
2. 5 A
■o
<
o
1
JAK2 phosphorylation
100 -
80 -
60
40 -
20 -
NOD
NOD+ db 5j db 5j+
Fig. 2. 5 A: Expression of P-JAK2 in leptin treated (+) and untreated PECs from NOD and
db 5j. Fig 2.5B: Measured band intensity for each sample representing the P-JAK 2
expression levels.
STAT 3 was phosphorylated in all the samples. Regardless of the leptin treatment, the
wild type PECs had similar expression of P-STAT 3, while leptin treatment increased the
STAT 3 phosphorylation in db 5j. Overall, P-STAT 3 has a higher expression in the wild
type than in the mutated PECs.
28
Fig. 2. 6 A
STAT 3 phosphorylation
12 -
10
■n
1 8
k '-
4 -
2 -
1
NOD NOD+ db5j db 5j+
Fig. 2.6B
Fig. 2.6A: Expression of P-STAT3 in leptin treated (+) and untreated PECs from NOD
and db 5j. Fig. 2.6B: Measured band intensity for each sample representing the P-STAT
3 expression levels.
Data implies that the JAK 2 and STAT 3 phosphorylation differences in wild type and
mutated mice. In NODs, without leptin JAK 2 and STAT 3 are both phosphorylated,
probably by other mechanisms (Fig. 2. 7). The treatment of leptin changes this in NOD
and dephosphorylates all the P-JAK 2, hence inducing STAT 3 phosphorylation. Protein
extracted exactly at this time may have caused the absence of P-JAK 2 in NOD+ (Fig.
2. 7). When compared to NOD, P-JAK 2 and P-STAT 3 both have low expressions in the
db 5js, but the effect of leptin stays similar. The untreated db 5j sample had a higher
29
expression of P-JAK 2 than the treated sample and vice versa for P-STAT 3 {Fig. 2.7).
This suggests that leptin have induced P-JAK 2 and elicited STAT 3 phosphorylation.
Phosphorylated JAK2 and STAT 3
^
■ JAK2
D STAT 3
dbSj
db5j+
Fig.2. 7: Comparison of P-JAK 2 and P-STAT 3 expression levels in leptin treated and
untreated PECs from NOD and db 5j mice. (+) sign indicates the leptin treated mice.
Overall, this data suggests that the Leprdb-sj mutation has an adverse effect on leptin
action and phosphorylation of JAK 2 and STAT 3. This could be due to reduced binding
of leptin to its mutated receptor as shown in the invitro studies using COS 7 cells. Leprdb-
5J mutation may have altered the dimerization or the folding of the leptin receptor causing
this low binding affinity. Altered folding could also affect the down stream
phosphorylation sites resulting low expression P-JAK 2 and P-STAT 3 (Fig. 2.7). As
JAK 2/STAT 3 pathway is responsible for inducing immune responses, findings from this
study might explain the development of juvenile obesity with T2D in db 5j mice instead
ofTlD.
However, adverse effects on JAK/STAT phosphorylation may not be the only reason for
resulting development of juvenile obesity with T2D in db 5j mice because leptin is
involved in other pathways. The MAPK, the insulin receptor substrate 1, and the
30
phosphatidylinositol 3 '-kinase (PI3'K) pathways (Martin-Romero et ai, 2001) are
mediated by leptin to induce T cell immune responses. (Sanchez-Margalet et al, 2001).
MAPK is involved in antiapoptotic effects in Periphderal Blood Mononuclear Cells
(Najib et al, 2002), whereas the PIB'K pathway may be important in regulating glucose
uptake (Bates et al., 2002). Leprdb-sj mutation on the leptin receptor might have an effect
on such leptin mediated pathways.
Studying the effects of Leprdbsj on MAPK and PIB'K using similar methods used in this
study would provide more information on the limiting of leptin action through its
receptor. Using db Ij mice - mice with a mutation on the intracellular region of leptin
receptor - would be a negative control for the above experiments. The negative controls
would confirm the observed reduction of JAK/STAT 3 phosphorylation by Leprdb-sj
mutation. To further study the role of leptin in JAK/STAT 3 pathway is to investigate the
expression of S0CS3. As SOCS 3 is down regulated by STAT 3 (Bjorbaek et ai, 1999),
based on data from this study one could predict to observe a higher expression of SOCS 3
in db 5j mice.
2.3 Conclusion
The data shows that Leprdbsj mutation has an adverse effect on JAK/STAT pathway,
which could result in the abnormal conditions observed in db 5j mice compared to its
wild type (NOD). Invitro data from '^^1-leptin binding to transfected COS 7 cells
suggested that leptins' low binding affinity to the mutated receptor could have affected
the JAK/STAT phosphorylation. The reduced phosphorylation of JAK/STAT may also
have caused by the alterations in dimerization and folding of the mutated receptor. These
results support the possibility of using db 5j mice as a novel way of studying leptin
mediated immime responses.
31
2.4 Bibliography
Bates, S. H., J. V. Gardiner, R. B. Jones, S. R. Bloom, and C. J. Bailey. 2002. Acute
stimulation of glucose uptake by leptin in 16 muscle cells. Horm. Metab. Res. 34:1 1 1.
Baumann, H., K. K. Morella, D. W. White, M. Dembski, P. S. Bailon, H. Kim, C. F. Lai,
and L. A. Tartaglia. 1996. The full-length leptin receptor has signaling capabilities of
interleukin 6-type cytokine receptors. Proc. Natl. Acad. Sci. USA 93:8374.
Bjorbaek, C, K. El Haschimi, J. D. Frantz, and J. S. Flier. 1999. The role of SOCS-3 in
leptin signaling and leptin resistance. J. Biol. Chem. 274:30059.
Bouloumie A, Drexler H.C, Lafontan M. and Basse R. 1998. Leptin, the product of Ob
gene, promotes angiogenesis. Circ. Res. 83:1059-1066.
Chehab F, Lim M, and Lu R. 1996. Correction of the sterility defect in homozygous
obese female mice by treatment with the human recombinant leptin. Nat. Genetics
12:318-320.
Cheng, A., Uetani, N., Simoncic, P. D., Chaubey, V. P., Lee-Loy, A., McGlade, C. J.,
Kennedy, B. P., and Tremblay, M. L. 2002. Attenuation of leptin action and regulation of
obesity by protein tyrosine phosphatase IB. Dev. Cell 2:497.
Ducy P, Amling M, Takeda S, Priemel M, Schilling AF, Beil FT, Shen J, Vinson C,
Rueger J.M, and Karsenty G. 2000. Leptin inhibits bone formation through a
hypothalamic relay: a central control of bone mass. Cell. 100:197-207.
Friedman J.M. 1998 Leptin, leptin receptors and the control of body weight. Nutr. Rev.
56:38-s46.
Gainsford T, Willson T.A, Metcalf D, Handman E, McFarlane C, Ng A, Nicola N.A,
Alexander W.S and Hilton D.J. 1996. Leptin can induce proliferation, differentiation, and
fiinctional activation of hemopoietic cells. Proc. Natl. Acad. Sci. USA 93:14564-14568.
Homo-Delarche F. 2004. Neuroendocrine immuno-ontogeny of the pathogenesis of
autoimmune disease in the nonobese diabetic (NOD) mouse. J. liar. 45:237-258.
La Cava A, and Matarese G. 2004. The weight of leptin in immunity. Nat Rev Immunol.
4:371-379
Lord, G. M., Matarese, G., Howard, J. K., Baker, R. J., Bloom, S. R. and Lechler. 1998.
Leptin modulates the T-cell immune response and reverses starvation-induced
immunosuppression. Nature 394:897.
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Lord GM, Matarese G, Howard JK, Bloom SR, and Lechler RI. 2002. Leptin inhibits the
anti-CD3-driven proliferation of peripheral blood T cells but enhances the production of
proinflammatory cytokines. J Leukoc. Biol. 72:330-338.
Martin-Romero, C., and Sanchez-Margalet, V. 2001. Human leptin activates PI3K and
MAPK pathways in human peripheral blood mononuclear cells: possible role of Sam68.
Cell. Immunol. 212:83.
Matarese G, Sanna V, Lechler R.I, Sarvetnick N, Fontana S, Zappacosta S, and La Cava
A. 2002. Leptin accelerates autoimmune diabetes in female NOD mice. Diabetes
51:1356-1361.
Najib, S., and V. Sanchez-Margalet. 2002. Human leptin promotes survival of human
circulating blood monocytes prone to apoptosis by activation of p4 2/44 MAPK pathway.
Cell. Immunol. 220:143.
Sanchez-Margalet, V. and Martin-Romero, C. 2001. Human leptin signaling in human
peripheral blood mononuclear cells: activation of the JAK-STAT pathway. Cell.
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Serreze D.V. and Leiter E.H. 2001. Genes and pathways underlying autoimmune diabetes
in NOD mice. In Molecular Pathology of Insulin-Dependent Diabetes Mellitus von
Herrath M, Ed. New York, Karger, p. 31-67.
Soria B, Skoudy A, and Martin, M. 2001. From stem cells to beta cells: new strategies in
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down regulation. Diabetes. 48: 279-286
33
CHAPTER 3
Sri Lankan Indigenous Medicine:
Diabetes as a Case Study
3.1 Introduction
Human health care has achieved great heights through innovations and discoveries made
by modem biomedical research. Having participated in such research, I am fascinated by
the importance and value it brings towards human health care. However, I am also
puzzled by the significance of such research to people living in developing countries such
as Sri Lanka, my homeland. I was raised in a society where indigenous medicine plays a
vital role in maintaining good health. Through this chapter I sought to expand my
knowledge of the role of indigenous medicine in the Sri Lankan health care system.
Since early history plant-based systems have played an essential role in human health
care. In spite of steadily evolving modern medicine, there has been a growing interest
towards traditional medicinal systems in the world, especially in the developed countries
(Simpson & Ogorzaly, 2001: Levetine & McMahon 2003: Shultes & Reis, 2003).
According to World Health Organization, about 80% of the population from the
developing countries still depends on traditional medicine and its practitioners (WHO,
1991). Many use only plant-derived medicine to prevent or cure minor and major health
conditions. Directly or indirectly, the remaining 20% in developing countries along with
several millions in the industrialized countries utilize plant-derived ointments or medicine
for many health issues (WHO, 1991).
In this chapter I have compared allopathic and indigenous approaches towards human
health care using treatment of diabetes as a case study. I gathered information on the
natural history, medicinal uses and pharmaceutical properties of plants used in Sri
Lankan indigenous medicine with a special focus on plants used in the treatment of
diabetes. I also discuss the current status of medicinal plant use and research in Sri Lanka
and stress the importance of conserving medicinal plants and the knowledge of their use
in traditional medicine.
35
3.2 EUstory of Indigenous Medical Systems
Dating back to 2600 B.C. in Mesopotamia, people used plants or their extracts for
medicinal purposes. Some of the plants they used, especially Cedrus (cedar).
Commiphora (myrrh), Papaver somniferum (opium poppy), are still widely-utilized
among many communities. Ebers Papyrus written by Egyptians in 1500 B.C., Chinese
"Materia Medica" written in 11 00 B.C. and Indian Ayurvedic medicine books written in
1000 B.C. include many plant-derived drugs and ointments for a number of diseases.
Since 300 B.C., Greeks and Romans have developed herbal medicine and have promoted
their use in the world. While Europe was in its Dark and Middle Ages, the Arabic empire
not only helped to protect Greco-Roman medicinal knowledge but combined it with
Chinese and Indian expertise. (WHO, 1991: Simpson & Ogorzaly, 2001: Levetine &
McMahon 2003: Shultes & Reis, 2003)
As in many other civilizations, Sri Lankans developed their own medical system with
extracts from mostly endemic or indigenous plants (Jayaweera, 1981: Dassanayake
1997). Indigenous medicine in Sri Lanka dates back to Pre- Aryan Era and was widely
practiced until western colonization introduced allopathic medicine. One account,
although controversial, notes that about 3000 years ago. King Rawana wrote the first-
knovra books on indigenous medicine of Sri Lanka. In the capital city of Sri Lanka,
historians and archeologists have found evidence of a hospital dating back to 400 B.C
and recovered surgical instruments and other equipment used for medicinal purposes.
(Ranasinghe, 1986). They have recovered evidence for well organized medi-care systems
with hospitals, rest homes, herb gardens and conserved forests of medicinal trees and
shrubs in all parts of the country (Mahindapala, 2004). Special rooms with specific
architectural designs for labor provide evidence for the attention early practitioners paid
on psychological condition of each patient during treatment. Another Sri Lankan king.
King Buddhadasa, was also a physician with a vast knowledge on medicinal plants, and
appointed a traditional practitioner for every ten villages (Mahindapala, 2004). This
primarily Sri Lankan system of medicine was identified as "deshiya chikithsa" meaning
36
indigenous medicine, although it was later influenced by Ayurveda, Siddha and Unani
medicine from other parts of the world (Serasinghe, 1994).
Allopathic drugs are based on one chemical compound that targets a certain organ in the
human body to stimulate a response. On the contrary, indigenous medicine fr)llows a
more holistic approach toward treating the human body (Samarasinghe, 1994). Sri
Lankan indigenous medicine (SLIM), unlike allopathic medicine, does not cure a disease
just by giving a specific drug. It divides therapy into three segments: pretreatment,
treatment and post-treatment. This ensures that the patient is frilly recovered without any
side effects or other health issues (Samarasinghe, 1994). But it does have a disadvantage:
it is a very long process that requires a longer time commitment from the patient.
Recently pharmaceutical companies have shown more interest on traditional medical
systems, particularly on their use of plants. Although some potentially-useful drugs may
be developed, this interest may have negative impacts on indigenous medicine and
communities unless care is taken at every step along the way, from field exploration to
the development of a drug (Silva, 1984). In this regard, it is critical that pharmaceutical
companies work with local governments and communities without exploiting the
medicinal plants, their habitats, traditional knowledge and the communities that depend
on them (Simpson & Ogorzaly, 2001)
3.3 Use of Plant Extracts in Modem Medicine
Scientists have discovered some of the most widely used drugs in allopathic medicine by
examining medicinal plants used in indigenous communities. Aspirin, a commonly used
drug throughout the world, is a compound extracted from white willow, Salix alba L.
(Salicaceae). It is believed that Hippocrates, the father of modem medicine used 5. alba
L., bark to treat fever few thousand years ago (Samarasinghe, 1994). Quinine, an anti-
malarial drug was extracted from Chincona officinalis L. (Rubiaceae) and used to treat
malaria patients in Europe. Historically, the plant has been widely used by the natives of
the Amazon to treat fever. Artemisinin, extracted from Artemisia annua L. (Asteraceae),
the most effective drug for malaria, was first identified by the Chinese practitioners 2000
37
years ago. One of the most frequently used anesthetics in modem medicine. Morphine,
was extracted from Papaver somniferum (Papaveraceae). Indigenous communities had
used this plant for about 4000 years as an analgesic. Probably the most important plant-
derived drug discovery in the 20* century is Paditaxel (Taxol® Bristol-Myers Squibb). It
is isolated from Taxus brevifolia Nutt. (Pacific Yew tree (E): Taxaceae), currently one of
the best known anti-cancer agents in the world (WHO, 1991). Plant species used in SLIM
have also contributed to the modern day drug discovery efforts. Vincristine and
Vinblastine, two anti-cancer agents, are derived from two Sri Lankan medicinal plants,
Rauvolfia serpentina (L.) Benth.ex Kurz (Ekaveriya(S): Apocynaceae) and Catheranthus
roseus (L.) G. Don (Minimal(S): Apocynaceae). These plant extracts are used in
allopathic medicine to treat leukemia (Samarasinghe, 1994). Over the last few decades
more than 100 chemical compounds have been extracted from about 90 plant species.
Most of them were discovered during attempts to isolate the active chemicals from a
plant used in traditional medicines (WHO, 1991).
The decline of indigenous medical knowledge is common throughout the world (Tissera,
1994: Widanapathirana, 1994: Shultes & Reis, 2003). However, many native
communities in Africa, South America and Eastern Asia still retain extensive knowledge
about use of plants in medicine. This knowledge is threatened due to the wide use of
allopathic medicine. Researchers along with organizations such as World Health
Organization and Biodiversity Conservation Network have taken major steps towards
rediscovering this knowledge. A careful study of these ancient medical systems could
provide novel therapeutic methods to prevent or even cure severe health conditions such
as diabetes, cancer and heart diseases. In this chapter, treatment of diabetes is used as a
model to study and compare existing indigenous and allopathic approaches towards
preventing or curing disease.
3.4. Diabetes and Allopathic Treatment
Allopathic medicine has identified several forms of diabetes. The most common is
diabetes mellitus which occurs because of lack of insulin or resistance to its action.
38
There are three main types of diabetes mellitus.
Type I Diabetes, also known as insuhn-dependent diabetes mellitus (IDDM) occurs
when the pancreas produces none or very little insulin. This causes plasma glucose
concentrations to elevate beyond the normal glucose concentration range (70-100 mg/dl)
(Parker et al, 2000). IDDM is a resuh of an autoimmune destruction of pancreatic _
cells, which produces insulin, and the reason for this destruction is not yet known.
Possibly there is a genetic link or predisposition for the degeneration of _ cells. However,
since the type I diabetes incidence is only 50% in identical twins, it is believed that
certain environmental factors may play a role (Brody et ai, 1998). Due to the
hyperglycemic condition of an IDDM patient, the urine volume increases ultimately
resulting in ketone bodies in the urine. Because of the loss of fluid from the body and
inability to utilize nutrients properly, these patients suffer from severe weight loss. If
diseased children are left untreated, they experience premature cessation of growth.
Under severe conditions of IDDM, unconsciousness, also known as diabetic coma, may
occur, and if appropriate therapies are not instituted, cardiovascular collapse and death
could result (Cabellero, 2003). Approximately 10 percent of people with diabetes have
type I diabetes (Bellazi, 2001).
Type II Diabetes, also called noninsulin-dependant diabetes (NIDDM), is the most
common form of diabetes and occurs when the pancreas does not produce adequate
insulin or when the body does not effectively use the insulin that is produced. What
causes NIDDM is still unknown, but a strong genetic component is likely involved
(Brody et al. 1998). This type occurs at a later age and in contrast to type I diabetes most
patients suffer from obesity and have a higher concentration of circulating glucose in
blood. The reduction of the number of insulin receptors is associated with obesity; hence
losing weight through exercise and diet could decrease insulin resistance (Derouich &
Boutayeb, 2002). Ninety percent of those with diabetes have type II (Stratta & Alloway,
1998). About one third of the diabetic population can use diet and exercise to control
their glucose levels while about another one-third of diabetics are controlled by diet
39
together with oral anti^diabetic drugs. Type II conditions that cannot be controlled by
either of the above methods require regular insulin injections (Sibenhofer et al., 2003).
Gestational Diabetes: This type is a temporary condition that occurs during pregnancy.
It affects two- to four-percent of all pregnancies and increases the risk of both mother and
child developing diabetes (B6)
Conditions that damage or destroy the pancreas, such as pancreatitis, pancreatic surgery,
or certain industrial chemicals, can cause diabetes. Certain drugs can also cause
temporary diabetes, while rare genetic disorders and certain hormonal disorders are
associated with or increase the risk for diabetes (Cabellero, 2003)
Insulin
The body needs insulin to decrease the blood glucose concentration. Glucose homeostasis
depends on several hormonal mechanisms to increase blood glucose (glucagons,
catecholamines, growth hormone, etc.) but only insulin to decrease it. Insulin is
synthesized, stored and released by -cells of Langerhans in the pancreatic islet, a
neuroendocrine organ that result in subsequent and smooth release of insulin, glucagon,
somatostatin and pancreatic polypeptide hormones (Soria et al, 2001).
Insulin was isolated in 1921-22 by Dr. Fredrick Banting and Dr. Charles Best at the
University of Toronto, Canada. On June 3, 1934, Banting, the co-inventor of insulin, was
knighted for his medical discovery. Before the discovery of insulin in 1921, everyone
with type 1 diabetes died within a few years after diagnosis. Although insulin is not
considered a cure, its discovery was the first major breakthrough in treating diabetes.
Insulin, a polypepetide contaning 51 amino acids, is arranged in two chains which are
linked by disulphide bonds. Insulin is produced by proteolysis of a precursor called
proinsulin in the granules of _ cells. After crystallization with Zn^^, insulin is stored in
these granules until _ cells receive a stimulus for their secretion. Although insulin has a
40
highly conserved sequence across species, there are some differences in the amino-acid
sequence of animal and human insulins (Brody et al, 1998).
Release of Insulin
With the increase of blood glucose, glucose concentration in _ cells increase. Glucose
metabolism inside the cell increases the intracellular ATP, and this ATP will close the
Katp channels in the _ cells. Katp channels are K"^ ion channels that are regulated by
ATP. Due to the depolarization caused by the closing of these channels, _ cells initiates
an influx of Ca^^ ions through voltage-gated Ca^"^ channels which results the release of
insulin.
Insulin receptors, which are membrane- spaning glycoproteins, contain two subunits; _
and _. The released insulin binds to the _ subunits of insulin receptors, and this activates
the tyrosine kinase activity of the _ subunits. Activation of tyrosine kinase increases
glucose and amino acid uptake to the cell. Additionally it results in some intracellular
activities such as an increase in RNA, DNA, protein synthesis and glycogenesis
(deposition of glycogens). Tyrosine kinase also promotes cell growth and has a
decreasing effect on lipogenesis (normal deposition of fat or the conversion of
carbohydrate or protein to fat) and lipolysis (Neal, 2002).
When one of the steps in the above mechanism fails, diabetic conditions occur, and the
two major treatments for this are insulin injections and administration of oral anti-
diabetic drugs. Regular physical activity has been recommended to diabetes patients
either to prevent and delay the onset of non-insulin-dependent diabetes or to assure good
control of diabetes (Wasserman etal, 1991).
Insulin Injections
Insulin may be extracted from pork pancreas and purified by crystallisation; it may also
be extracted from beef pancreas. Human sequence insulin may be produced
semisynthetically by enzymatic modification of porcine insulin or biosynthetically by
41
recombinant DNA technology using bacteria or yeast (Sibenhofer et al., 2003). All
insulin preparations are to a greater or lesser extent immunogenic in humans, but
immunological resistance to insulin action is uncommon. Preparations of human
sequence insulin should theoretically be less immunogenic, but no real advantage has
been shown in trials (Brody et al., 1998; Sibenhofer et al., 2003).
Insulin is required by all patients with ketoacidosis, and it is likely to be needed by most
patients with rapid onset of symptoms, substantial loss of weight, weakness and
ketonuria. Almost all diabetic children need insulin administration. It is also needed for
type II diabetes when other methods fail to achieve good control (Sibenhofer et al.,
2003).
Gastro-intestinal enzymes inactivate insulin, and must therefore be given by injection; the
subcutaneous route is ideal in most circumstances (Sibenhofer et al., 2003). Once
injected, the insulin binds to the insulin receptors and stimulates tyrosine kinase activity.
In humans the half-life of circulating insulin hormone is about 8 minutes and insulin acts
on glucose or lipid metabolism rapidly after it binds to the insulin sensitive cells. Hence,
it is important to make insulin preparations with long duration time and a faster onset.
This can be done by increasng the particle size of the preparation or by complexing the
insulin with zinc or protamines (highly basic proteins) (Brody et al., 1998).
There are 3 main types of insulin preparations:
• Those of short duration have a relatively rapid onset of action. These can be
administered at hyperglycaemic emergencies. One of the short-acting types is
soluble insulin, which is a simple solution of insulin but has a very slow onset
compared to what is releaed by _ cells. Newly-developed insulin lispro and
insulin aspart, which are analogues of insulin, have a faster onset (O.Shrs) but a
shorter duration (3 hrs) (Brody et al., 1998).
• Those with an intermediate action, e.g. isophane insulin (a complex of protamine
and insulin) and insulin zinc suspension (Sibenhofer et al., 2003). Due to the
42
excess of protamine, when zinc insulin suspension is injected it dissloves slowly
resulting in a prolonged duration of insulin activity (24 hrs). This can be too long
to achieve good control in reducing blood gucose. To overcome this problem
isophane insulin, which has lower concentrations of protamine, was developed.
After the isophane insulin injection protelytic enzymes degrade the protamine,
insulin is absorbed into the cells (Brody et ai, 1998).
• Those whose action is slower in onset and lasts for long periods (36 hrs), e.g.
extended insulin zinc suspension and protamine insulin zinc suspension. The
advantage of having protamine zinc insulin suspension is that it can be mixed in
any proportion without harming its stability or activity. The smaller concentration
of protamine avoids its' allergies while zinc helps to maintain the prolonged
action. Extended insulin zinc suspension dissolves very slowly which results in a
slow onset (6-lOhrs) and longer duration (36 hrs). due to its large particles (Brody
et al, 1998). However, using the same mixture with smaller particles increases
the solubility and the insulin preparation has a faster onset and longer duration.
Semilente insulin is a smaller particle insulin suspension (Sibenhofer et al, 2003).
Type I patients use regimens of insulin contaning a mixture of short-acting and
intermidiate-acting insulin preparations. To achive normoglycemic levels, more intensive
regimens are used (Neal, 2002), and insulin injections are the only effective drug used in
treating type I diabetes.
Hypoglycaemia is a potential problem for all patients receiving insulin and patients must
be instructed carefully to prevent it. Very tight control of diabetes lowers the blood-
glucose concentration that is needed to trigger hypoglycaemic symptoms (Sibenhofer et
ai, 2003). Under sever hypoglycemic levels, coma (insulin coma) and death could occur
if the patient is not treated with glucose (Wasserman, 1991).
43
3.41 Oral Antidiabetic Drugs
Sulfonylureas
Sulfonylureas, containing benzene and amide groups, are oral drugs that stimulate the
pancreas to release insulin and enhance the insulin sensitivity. Both these actions require
circulating insulin in blood or _ cells that are capable of producing insulin. Hence,
sulfonylureas are only effective in type II patients. These agents bind to Katp channels
and inhibit K^ release which depolarizes the _ cell membrane. This results in an incerease
entry of Ca^^ ions into the cell through the voltage gated Ca^"^ channels. This enhances
the insulin secretion from _ cells (Brody et al., 1998). Glybenclamide, tolbutamide,
glipizide and glicazide are some of the sulfonylureas in use. Glipizide and glicazide are
commonly used short-acting drugs which are tried first on patients. Glybenclamides has a
prolonged diu'ation but may cause hypoglycemia. Thus the patients with higher risk of
hypoglycemia should be given tolbutamide which has a very short duration.
Combinations with small amounts of insulin or with other drugs (such as metformin or a
thiazolidinedione) may extend their benefits (Ducobu, 2003). Sulfonylureas pose a lower
risk for hypoglycemia than insulin does. However, the hypoglycemia produced by
sulfonylureas may be prolonged and dangerous compared to insulin injections (Malik &
Trence, 2003).
Meglitinides
These agents stimulate beta cells to produce insulin, although the exact mechanism is
uncertain. These agents are rapidly metabolized and short acting, and if taken before
every meal, they actually mimic the normal effects of insulin after eating. They may be
good agents for people with potential kidney problems. The main side effects include
diarrhea and headache (Ducobu, 2003).
Metformin
Metformin, a biguanide agent, appears to increase the glucose uptake and the reason is
yet to be discovered (Neal, 2002). Since there is no increase in the release of insulin,
metformin has a very little hypoglycemic action; hence it is also known as
44
antihyperglycemic drug. Combinations of metformin with insulin-secreting drugs, other
insulin-sensitizing drugs, or insulin itself are proving to be particularly effective. Since it
does not cause hypoglycemia or add weight, it is particularly well suited for obese type 2
patients. Metformin also appears to have beneficial effects on cholesterol and lipid levels
and may protect against heart diseases. Gastrointestinal problems including nausea, and
diarrhea and reduced absorption of vitamin B12 and folic acid, which are important for
protection against heart disease, are common side effects of metformin (Malik & Trence,
2003)
Thiazolidinedione
Also called glitazones, Thiazolidinedione improves insulin sensitivity by activating
certain genes involved in fat synthesis and carbohydrate metabolism. It not only binds to
a member of a nuclear receptor super family of ligand-activated transcription factor,
called PPAR-_, but also increases the expression of certain insulin-sensitive genes (Brody
et al, 1998). Thiazolidinediones do not cause hypoglycemia when used alone, although
they are usually taken in combination with sulfonylureas, insulin or metformin.
Rosiglitazone (Avandia) and pioglitazone (Actos) are the currently approved
thiazolidinediones. These drugs are usually taken once or twice per day. Since they only
enhance insulin sensitivity indirectly, it may take several days before the patient notices
any results from them and several weeks before they take full effect (Ducobu, 2003)
It has recently been found that thiazolidinediones produce very favorable effects on the
heart, including reducing blood pressure and improving triglyceride and cholesterol
levels (Malik & Trence, 2003). They may also block a molecule called IIBest HSK-I
that may play a significant role in the metabolic syndrome (a prediabetic condition that
includes high blood pressure and obesity) as well as diabetes type 2. One study also
suggested that they may even improve beta-cell function and so help prevent progression
of diabetes (Ducobu, 2003). Thiazolidinediones can cause anemia and, as with other oral
agents, can cause moderate weight gain (Neal, 2002)
45
Alpha-Glucosidase Inhibitors
These drugs, acarbose and miglitol (Glyset), reduce glucose levels by interfering with the
absorption of starch in the small intestine. It inhibits -gucosidases which are complex
carbohydrate degrading enzymes. Acarbose tends to lower insulin levels after meals, a
particular advantage, since higher levels of insulin after meals are associated with an
increased risk for heart disease. The most common unpleasant side effects are flatulence
and diarrhea (Neal, 2002).
Potential Drug Treatments
Investigations on the autoantigens that cause _ cell destruction in type I patients could
lead to possible drug development to prevent the autoimmune activity. Also the research
done on the relationship between glucokinase activity and _ cell stimulation to release
insulin as well as the genetic component of type I and II diabetes could be helpful in
developing new drugs to control diabetic conditions. The increasing understanding on
insulin activity on obesity, diabetic conditions and other complication has opened many
possible approaches towards designing new drugs (Soria et al, 2001). An understanding
of approaches taken by indigenous medical systems, such as those practiced for
thousands of years in Sri Lanka, can also help find cures for and methods of prevention
of diabetes.
3.5 Sri Lankan Indigenous Medical approaches to the Treatment of Diabetes or
"Madumeha"
Diabetes was identified by the ancient Indians as early as 6* century B.C. while the first
description of diabetes mellitus in western medicine only came in 1675 A.C. (Perera,
1993). The Indian practitioner Susruta described diabetes as "Madumeha" meaning "rain
of honey." In ancient Hindu medicine, diabetes has always been treated with oral
administration of herbal plant extracts (Chaudri & Vohra, 1993).
46
Charaka Sanhita written by Charaka in 5 century B.C. in India, is one of the most
commonly used Ayurvedic books in SLIM. Charaka has identified diabetes as sweetness
of urine (Chaudri & Vohra, 1993). Ayurveda identifies the pathology and therapeutics
connected with urinary/kidney system diseases, while classifying them into 20 categories,
or called "visiprameha." This classification includes hematuria, glycosuria and diabetes
and mentions that diabetes can only be controlled or prevented but not fully cured.
Charaka Sanhita and other Ayurvedic literature have clearly described not only the
importance of glucose or "Sharkara" to the human body but also its activity and synthesis
(Perera, 1993).
Ayurveda mentions two diabetic conditions: release of urine with sweetened properties or
excessive urination without any sweetened properties. The first condition is identified in
modem science as Diabetic Mellitus and the latter as Diabetic Insipidus (Jinadasa, 1993).
An ancient Ayurvedic book called Shushrutha Chikithsa Stana identifies two major
categories of diabetes: Sthula (Obese) and Krusha (Thin) types. This book describes that
these types should be treated differently. The symptoms described under Krusha and
Sthula highly resemble what modern science identifies as type I and II diabetes,
respectively (Wijekoon & senadheera, 1993)
Ayurvedic literature has mentioned people who lack physical exercise, sleep excessively,
and consume excessive amounts of food with high fat and sugar are highly prone to
diabetes later in life. It has identified three causes of diabetes: inheritance, obesity and
malfunctioning of certain hormones. Ayurveda further describes different symptoms that
occur with either type of diabetes (Jinadasa, 1993: Perra, 1993).
The principal and initial symptoms of having high blood glucose level indicate firequent
urination, excessive thirst, extreme hunger, increased fatigue, blurry vision and
numbness. These Ayurvedic books mention two symptoms that are specific to diabetes.
They are increased acidity of urine (modem day known as ketoacidosis) and any amount
of glucose in urine (Jinadasa, 1993: Perra, 1993, Ramanayake, 2002). They emphasize
47
that it is very important to consider all the symptoms very carefully. They also describe
two other situations that could cause the presence of glucose in urine. In modem times
they are known as renal glycosuria (nondiabetic glycosuriya) and melituria (such as due
to kidney disfunctions) (Vidyathilake, 1993).
Adopted from Indian Ayurvedic books, SLIM practitioners have treated diabetes for
thousands of years. Because diabetes is becoming increasingly common in Sri Lanka, a
large group of indigenous medicine practitioners are currently conducting clinical and
animal research trials based on indigenous medicine to find a cure for diabetes (Jinadasa,
1993: Perra, 1993: Karunadasa, 1993). Thier research has shed light on the reasons for
high susceptibility of the current Sri Lankan population to diabetes and described
necessary steps to be taken to avoid or control this disease.
Dr. D.M. Jayasingha, a well-known practitioner and researcher, has experience with
treating diabetic patients who were not cured by western methods of treatment. He
describes the importance of understanding the type of diabetes as mentioned in
Ayurvedic literature and using plant extracts accordingly (Jayasingha, 1993)
There are about 35 medicinal plants used in Sri Lanka to prevent or control diabetes
{Table 3. 1). Some of these plants have been investigated by modem scientists for their
anti-diabetic properties, while many still remain unknown to the rest of the world. Most
of these plants are also used in Indian traditional medicine to treat diabetes {Table 3.2),
while others are only used in SLIM.
48
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3.6. Plants Used Against Diabetes in Sri Lankan Indigenous Medicine
Spondias dulcis Sol. ex Parkinson. (Anacardiaeeae)
Common Names: Ambarella (S), Otaheite Apple (E)
Distribution: Native to South and South East Asia
Ecology: This plant is found in the wet zone of Sri Lanka. It is commonly grown in the
central and Southern Provinces, but can be seen throughout the country. Spondias
pinnata, a related species, is grown in the northeastern parts of Sri Lanka but not used in
SLIM. This plant is closely related to Mangifera indica (mango), which is also used for
diabetic treatment
Use in diabetes: Cooked or uncooked fruits are recommended for diabetic patients.
Liquid extract from bark is given to control hyperglycemic conditions.
Other medicinal uses: Fruits are known to prevent heart disease. Fruits and bark extract is
given to prevent urinary problems, throat infections and gastritis. It is also used to reduce
phlegm produced in the lungs and thought to be good for asthma patients. Ripe fruit is
considered to be cooling and could be used against tonsillitis. Women who suffer from
leuchorroea are recommended to eat fruits.
Cultivating and harvesting: The plants are cultivated mostly by planting the seeds, but
roots and stem cuttings can also be used. Within a year, about 100 kg of fruit can be
harvested from a mature tree.
Pharmaceutical properties: Unknown
Sources: 01,09, 18,30 & 31
49
Mangifera indica L. (Anacardiaceae)
Common Names: Amba (S), Mango (E)
Distribution: Native to India and naturalized in Sri Lanka
Ecology: This plant can be found throughout the wet zone of Sri Lanka and is grown in
many home gardens. Many different varieties of this plant are found around the country
including M zeylanica, a species endemic to Sri Lanka.
Use in diabetes: Although it is mentioned in Ayurveda, SLIM has not used any part of
this plant to treat diabetes.
Other medicinal uses: Ayurveda has described the different medicinal properties of ripe
and unripe fruits, roots, leaves, bark and seeds of this plant. Extracts from some of these
organs are used to control excessive sweating, prevent vomiting, and relieve sore throat.
It is knovm to be good for patients with heart-related diseases.
Ayurveda has specifically mentioned the side effects of consuming excessive amounts of
these fruits. People believe leaves contain certain disinfectant properties and hang them
outside the door way to purify the house.
Cultivating and harvesting: Seeds are often used in cultivation. Because of the economic
value of the fruit, many varieties of the same plant are developed via biotechnologies,
such as tissue culture and genetic engineering. Modified varieties are developed and they
are resistant to certain climatic conditions and diseases. Fruits and other organs can be
extracted in a considerably shorter period of time from the modified varieties than from a
regular plant.
Other: One of the most common fruits in Sri Lanka. It is very popular among the general
population. Fruits are used as a vegetable in Sri Lankan cuisine, leaves in Hindu religious
50
ceremonies and wood for construction. Flowers and fruits are involved in certain
romantic myths in Asian history.
Pharmaceutical properties: Known chemicals are inorganic ions, amino acids tannin,
fattyacid stearic (46.3%), oleic (40.0%) , palmitic, linoleic, arachidonic, behenic acids,
5,6,5',6'-diepoxy-b-carotene carotenoid .triterpenoids tetracyclic triterpenoids, 3-
caraene, Et butyrate, butyric acid, a-pinene . stearic acid (48%)
Sources: 03, 04, 05, 07, 09, 18, 30 & 31
Lasia spinosa L. (Araceae)
Common Names: Kohila (S)
Distribution: Native to the region ranging from India to Papua New Guinea
Ecology: This plant can be grown under any climatic condition and is commonly found in
wetlands and moist soils.
Use in diabetes: Leaf and tuber extracts are given to diabetic patients and are known to
reduce blood glucose levels.
Other medicinal uses: This plant is well-described in the Ayurvedic books where each
part of the plant is categorized according to its medicinal properties. Flowers contain
properties that aid gallbladder diseases. Leaves are known to prevent digestive system
diseases and are good for the liver. The fibers of tuber and stems reduce constipation.
Cultivating and harvesting: Mature stems are used for cultivation and within 4-6 months
tubers and leaves can be harvested for medicinal purposes and food.
51
Other: It is consumed as a food more than a medicine and not many are aware of the
great medicinal properties of its leaves and tuber. In Ayurveda and SLIM, it is divided
into different varieties according to the size or starch content of the plant, leaf or tuber.
Apart from medicinal values, this plant is also used in many mystic and religious
activities. It is believed that by lying next to leaves brings a good night of sleep to
patients wdth insomnia.
Pharmaceutical properties: Recent studies at the University of Colombo, Sri Lanka, have
shown that leaves, tuber and stems contain high levels of -carotenes and could be used
as a source of vitamin A. Most of the nutrients are lost during the process of cooking,
hence uncooked leaves are thought to be the best. Stems contain hydrocyanic acid.
Sources: 01,09, 18, 30 & 31
Sphaeranthus indicus L. (Asteraceae)
Common Names: Mudumahana (S), East Indian Globe Thistle (E)
Distribution: Native to India, Sri Lanka, Burma, Austrailia and Malaysian Islands
Ecology: This plant is often found adjacent to rice fields in the Central and North Central
Provinces of Sri Lanka.
Use in diabetes: Extracts from all the organs of this plant are used in treating diabetes and
related urinary system conditions in SLIM.
Other medicinal uses: Leaves, flowers and fruits are used to treat skin infections, stop
external bleeding and suppress cough. Traditional communities in Sri Lanka use plant
extracts as a blood purifier to prevent skin diseases. It is also used in India, Malaysia,
Afiica and China as a medicinal plant.
52
Cultivating and harvesting: Seeds are collected from dried fruits and used for cultivation.
Currently about 1400 kg are used in Ayurvedic medicine factories in Sri Lanka. About
60% is used in the dried form.
Pharmaceutical properties: Known chemical components of this plant are diglucoside, I
Eudesmanoids, 11 alpha, 13-dihydro, sesquiterpene glycoside, sphaeranthanolide, 7 a-
hydroxyeudesmanolides, sequiterpenoids, cryptometidiol, 4-epicyptomeridiol
Sesquiterpene lactones eudesmanolide, Bicyclic sesquiterpene lactone, 5-alpha-7-
hydroxyeudesmanolide, 7-alpha-hydroxyfrullanolide, cytotoxic sesquiterpenoid lactone,
Eudesmanolides, sesquiterpenoids, cryptomeridiol, 4-epicryptomeridiol
Sources: 07, 09, 18, 25, 30 & 31
Gymnema sylvestris (Retz.) R. (Asclepiadaceae)
Common Names: Masbeddha (S), Peripolca of the Woods (E)
Distribution: Native to tropical Africa, Deccan of India, Sri Lanka
Ecology: This plant is commonly found adjacent to tall trees in the secondary forests of
the Dry Zone in Sri Lanka. However, it is cultivated throughout the country.
Use in diabetes: Leaf extracts are used as a cure for diabetes in SLIM. Only leaves
contain anti-diabetic properties.
Other medicinal uses: Leaf extract is given to patients with gallbladder and kidney
problems. Seed extracts cure influenza and tuberculosis. Root bark is good for eye
diseases. Certain traditional practitioners believe that the leaf extract can be used to
increase fertility in both males and females. Roots of the vine induce vomiting; traditional
53
communities in India, Western Africa and Australia use roots to treat venomous snake
bites.
Cultivating and harvesting: This can be cultivated by planting seeds. Within a couple of
years fruits and leaves can be harvested. Interestingly, a rather small quantity of G.
sylvestris is used among traditional drug manufacturers while a larger amount is sold in
local markets.
Other: There has been confusion over the identity of this species, as communities in
different regions of Sri Lanka identify different varieties of this plant The genuine plant
mentioned in the SLIM is a strong vine with leaves that can numb taste buds in the
tongue, particularly taste buds for sugar.
Pharmaceutical properties: Studies have shown that the leaves can stimulate the -cells
in the langerhans to secrete insulin and another unknown endocrine hormone.
The chemical components are hentriacontane, pentariacontane, _ -chlorphylls, phytin,
resins, tartaric acid, formic acid, butyric acid, anthraquinone, inositol, d-quercitol
"gymnemic acid", quercitol, saponins, gymnemic acid III, IV, V, VIII and IX,
dammarane-type saponins gymnemasides I- VII, gypenoside XXXVII, LV, LXII LXIII,
Gymnema saponins I-V, Oleanane-type saponins ,triterpene saponins, Gymnemic acid
tritepenoid saponins gymnemasins A, B, C and D.
Sources: 07, 09 & 18
54
Berberis aristata DC (Berberidaceae)
Common Names: Daruhidra (S) Indian Barberry (E)
Distribution: Native to Himalayan region in India and the highlands of Sri Lanka
Ecology: This plant grows in the cold high alatitude grasslands of Sri Lanka. Three other
Berberis species are found in Sri Lanka, one of which is endemic. However they are not
used in traditional medicine, hence medicinal properties are unknown.
Use in diabetes: Fresh root and bark extracts of this plant are used in diabetic treatment.
Other medicinal uses: Every part of this plant is used in medical treatments. It is known
to be good for illnesses in digestive system, inflammatory bowel disease, mouth diseases,
liver, stomach and intestinal diseases, eye irritations, and skin infections.
Cultivating and harvesting: This can be cultivated via seeds or stem cuttings and grown
only in the cold high alatitude areas. Once the plant is mature, stems are collected and
dried in mild sun. They can then be stored in a dry area for a long period of time. They
are sold in the local herbal markets and are considered as one of the most expensive
herbal plant extracts.
Other: This is not a commonly used plant in Sri Lanka, mainly because it is not widely
found. It is a prominent medicine mentioned in the Ayurvedic medicine and is widely
used in India. For over 1500 years, Sri Lankan traditional practitioners have been using a
substitute plant called Coscinium fenestratum (Gaertn.) Colebr (Venival (S):
Menispermaceae), which is believed to have similar medicinal values.
Pharmaceutical properties: Unknown
Sources: 01,03, 04, 05, 07, 09 & 18
55
Stereospernuim suaveolens DC (Bignoniaceae)
Common Names: Pallol (S), Messenger of Spring (E)
Distribution: Endemic to India, but naturalized in Sri Lanka
Ecology: In Sri Lanka this plant is cultivated as a medicinal plant in different areas,
especially in herbal gardens.
Use in diabetes: Leaves have anti-diabetic properties and it is recommended that diabetic
patients eat leaves with rice. Ground flowers or an extract made from the flowers are also
given to diabetic patients to control blood glucose levels.
Other medicinal uses: Roots, leaves, flowers and bark are used for a variety of purposes,
and Ayurvedic books have described its medicinal properties for each organ.
Flowers and leaf extracts are knovm to be good for heart, lung and kidney-related
diseases. Roots are given to induce breast milk. Flowers are also known to contain a
property that induces sperm production in infertile males.
Cultivating and harvesting: Stem cuttings and seed are used for cultivation. In about 3
years, plant parts can be extracted for medicinal purposes.
Other: Traditional practitioners in Sri Lanka use this plant as a substitute for
Stereospermum personum, which is mentioned in Ayurvedic books.
Pharmaceutical properties: Unknown
Sources: 01, 03, 04, 05, 07, 09, 16, 18, 25, 30 & 31
56
Kokoona zeylanica Thw. (Celastraceae)
Common Names: Kokum (S)
Distribution: Endemic to Sri Lanka
Ecology: This rare plant is mainly found in the wet areas of forests in Sri Lanka
Use in diabetes: In SLIM, the bark extract is used to reduce blood glucose levels in
diabetic patients.
Other medicinal uses: Bark extract is also used for snake bites, eye diseases, as a nasal
inhaler to relieve headaches, to remove zits and gain soft, smooth skin. Bark extract is
still used among women, even in the urban areas, to maintain a healthy and beautiful
skin. The oil extracted from leaves and bark is used as an insecticide in rural areas of Sri
Lanka.
Cultivating and harvesting: Seeds obtained from fruits are used for cultivation.
Other: Before the Europeans brought soap to Sri Lanka, finely-ground bark from this
plant was mixed with water and sun-dried to make soap. It is still popular among women
in Sri Lanka and India.
Pharmaceutical properties: Known chemical components are demethylzeylasterone (5),
6-oxophenolic, celastranhydride
Sources: 03, 04, 05, 07, 09, 18,30 & 31
57
Terminalia chebula (Combretaceae)
Common Names: Aralu (S), Myrobalan (E)
Distribution: Native to India, Burma, Malaysia, Sri Lanka and Thailand
Ecology: This plant is grown in dry grasslands and Savannas in Sri Lanka, certain areas
in the Eastern Province are natural habitats for this plant.
Use in diabetes: Fruits of this plant are used in almost every medicinal preparation for
treating diabetes.
Other medicinal uses: One of the most prominent medicinal plants in Ayurveda and
SLIM. The fruit contains preventative qualities for many common diseases. It is known
to prevent diseases occurring from three "doshas" (imbalance of phlegm, bile & air)
known in Ayurveda. Fruits are commonly used to treat intestinal ulcers and digestive-
related and gum diseases, as well as mouth ulcers. Traditional communities believe
consuming the fruit aids in keeping one healthy.
Cultivating and harvesting: This plant is cultivated by planting seeds. Seeds have a thick
seed coat. In order to break dormancy either the seed coat is crushed or the seed is soaked
in water. Communities in eastern parts of the country collect seeds from the tree and sun
dry them before sending them off to local markets.
Other: Mentioned as a medicinal plant in old Buddhist prayers and in mythical stories,
this plant was thought to have evolved from drops of the drink of the gods fallen to Earth.
In addition to medicinal uses, fruit extracts are used as a pesticide, mouth cleanser and
food. The trunk is used as timber and dyes are made from seed extracts.
58
Pharmaceutical properties: The fruit contains many chemical components. Known
chemicals are tannins (pyrogallol type) chebulagic acid, chebulinic acid corilagin,
hebulic acid, 6-digalloylglycose, ellagic acid, gallic acid, glucogallin, terchebin, 3, 6-
trigalloylglucose 1,2,3,4,6-pentagalloyl- glucose sugar. Glucose, sorbitol, fructose,
sucrose, gentiobiose arabinose, maltose, rhamnose, xylose succinic, quinic, shikimic,
dihydro dehydroshiimic acids, chebulin, Terminalic acid (l-0-galloyl-2,4-chebuloyl-
b-D-glucopyranose), 9-(2-hydroxyethoxymethyl) guanidine
Sources: 0)1,09, 18
Ipomoea pes-caprae (L.) R. Br. (Convolvuiaceae)
Common Names: Bimthamburu (S), Goats Foot Creeper (E)
Distribution: Naturalized from Arabia through tropical Asia
Ecology: This plant grows along the coasts in the wet zone of Sri Lanka. Practitioners
have identified two varieties of the same species and have divided them according to their
medicinal value.
Use in diabetes: Ground leaves are used to cure wounds caused by diabetic conditions.
Other medicinal uses: Leaf extract is used to relieve cramps, cure skin diseases, arthritic
conditions and prevent bacterial infections in feet. Certain traditional communities use
this plant to cure sexually transmitted diseases.
Cultivating and harvesting: Stem cuttings from vines are used for cultivation. If grown
under bright sun under proper soil conditions, leaves can be collected within a month.
About 2000 kg of leaves are sold in local markets annually.
59
Other: It is also a commonly-used medicinal plant among natives in Australia,
Madagascar and Brazil.
Pharmaceutical properties: Extracted chemicals from this plant are fatty acid glycosides,
designated pescaprosides A, B and E. Pescaproside Epentaglycoside of 11-
hydroxyhexadecanoic acid. Mucilage, volatile oil (0.05%), resins (7.3%) bitter
substances, red coloring matter, pentatriacontane, triacontane, sterol, behenic, melissic,
butyric myristic acids, 2-hydroxy-4, 4,7-trimethyl-l (4H)-napthaleone, (-) mullein,
eugenol, 4-vinyl guaiacol
Sources: 01, 03, 04, 05, 07, 09, 16, 18, 30, 31 & 47
Aporusa lindleyana (Euphorbiaceae)
Common Names: Kaballa (S)
Distribution: Endemic to Sri Lanka
Ecology: It is found above 900 m altitude in the primary and secondary forests
throughout the country and is widely cultivated along stream banks.
Use in diabetes: In SLIM, the plant is identified as a blood and urine purifier. Traditional
practitioners recommend that patients with diabetes or suffering from obesity eat salad
made from its leaves.
Other medicinal uses: Immature leaves are a remedy for digestive system illnesses, eye
diseases and eating disorders. However, since this plant is endemic to Sri Lanka, none of
the Ayurvedic books from India mentions it.
Cultivating and harvesting: Seeds or stem cuttings are used for cultivation. Within a year
leaves can be collected for food or medicine.
60
Pharmaceutical properties: Unknown
Sources: 09, 3>0 8!.3\
Phyllanthus emblica L. (Euphorbiaceae)
Common Names: Nelli (S), Emblic myrobalan (E)
Distribution: Introduced to Sri Lanka, native to India.
Ecology: This plant is commonly found in the forests in Sri Lanka, but is grown
throughout the country.
Use in diabetes: The extract from root covering of P. emblica is given with turmeric and
bee honey to diabetic patients.
Other medicinal uses: In SLIM the leaves, bark, roots, fruits, seeds and flowers are used
for different medicinal purposes. In addition to curing the digestive system illnesses,
fruits are used to increase the sperm count in males and prevent heart disease. Leaves and
fruits are good for urinary infections.
Cultivating and harvesting: Stem cuttings or seeds that are sun dried and soaked in water
overnight are used for cultivation. In about five years fruit can be collected and used
either fresh or dried. Fruits are sold in local markets for high prices. In order to meet the
demand, the government recently imported dried fruit from India with an approximate
cost ofUS$ 60,000.
Other: This plant has been used as a medicine in Ayurveda and SLIM since early history.
The fruit is mentioned in Sinhalese literature from 1500 years ago and known as the
61
medicine of gods. The fruit juice is thought to be as good as the drink of gods. Queens
and women of the royal family use bark extracts to maintain a smooth skin. It is one of
the famous triple (tripala) herbs used in Ayurveda. Because of the high percentage of
vitamin C in the fruit, it is also recommended as a healthy fruit by the western doctors.
Pharmaceutical properties: Known chemicals are triterpenoids, flavonoids, tannins,
alkaloids, phenolic acides. Flavonoids, lupeol, lupenone, quercetin, kaempferol,
kaempferol 3-0-glucoside (=astragalin), tannins, phyllembin, gallotannin as 1,2,3-
trigalloylglucose, ellagitannins terchebin, corilagin, chebulagic acid, chebulinic acid.
Vitamin C (470-1810mg/100g), trigalloylglucose, ellagic acid, corilagin, terchebin,
phyllemblin, phyllemblic acid and emblicol. 16% oil, Linoleic acid (44%), oleic acid
(28.4%) linolenic acid (8.8%), stearic acid (2.2%) palmitic acid (3.0%) myristic acid
(1.0%)Ellagic acki,empferol, kaempferol-3-glycosideamlaic acid, lupeol, -
sitosterol, ellagic acid. Lupeol (+)-leucodel-phinidun. Ester glycoside. Phyllaemblicins A,
B, and C. Methyl ester of a highly oxygenated norbisabolane, phllaemblic acid (1).
Tarmins, putranjivain Aquercetin.
Sources: 01, 03, 04, 05, 07, 09, 18, 25, 30 & 31
Pterocarpus marsupium (Fabaceae )
Common Names: Gammalu (S) Indian Kino Tree (E)
Distribution: Native to Malaya, Andaman Islands and naturalized in Sri Lanka, India
Ecology: This plant is often found in high altitude areas in the intermediate and dry zones
of Sri Lanka. The damage done to the tree by unregulated collection of sap has caused
this plant to decline in Sri Lanka.
62
Use in diabetes: In SLIM, the leaves, xylem, bark, and sap have been used to treat
diabetes. It is believed that drinking water steeped overnight reduces the blood glucose
levels. The sap collected from the tree is also known to have anti-diabetic properties.
Other medicinal uses: Leaf, sap and bark extracts are also used to treat cystic fibrosis and
are known to increase one's vision, reduce dental problems and prevent certain skin
diseases. The sap increases red blood cell count in those suffering from anemia.
Cultivating and harvesting: Seed can be extracted from mature fruits during May and
June. To harvest the sap effectively, sap is collected only from 20-year-old trees.
Collections take place before sunrise since sunlight solidifies the sap and turns it into
glue. Collected sap can be stored in a bottle for long periods. Wood can be obtained from
30-35 year-old trees. Only the reddish brown region (pith and wood) in the center of the
trunk is used in SLIM.
Other: This plant had been popular among the 17* century wood craftsmen. It is believed
that Europeans brought this tree to Sri Lanka from India. However, there is a
contradiction here since the free has been used to freat diabetic patients prior to the arrival
of the Europeans.
Pharmaceutical properties: Known chemicals are -epicatechin. Liquiritigenin,
isoliquiritigenin, alkaloid (0.017%^sin (0.9%). Yellow colouring matter (5%)
essential oil semi-drying fixed oil (0.5%). Non-glucosidal tannin, kinotarmic acid (5-8%),
kinoin kino-redatecholpyi(ocatechin)yotocatechuic acid, resiigalljxECtkcid,
kinotannic acid.
Sources: 01, 03, 04, 05, 07, 09, 18, 25, 30 & 31
63
Cassia auriculata (Fabaceae)
Common Names: Ranawara (S), Mature Tea Tree (E)
Distribution: Native to Sri Lanka and India
Ecology: This plant can be found by the coasts and forests in Sri Lanka. A related
species. Cassia divaricata, is another common plant in Sri Lanka but is not used in
SLIM.
Use in diabetes: An extract made from the flower and the leaf buds contains anti-diabetic
properties and is used as a refreshing drink in rural communities. Traditional doctors use
the flower to maintain normal blood-glucose levels. Ground seeds are also used in
treating diabetics.
Other medicinal uses: All parts of this plant are used in SLIM, but leaf buds are known to
be most effective. Certain plant parts are used to cure eye diseases and as a pain reliever.
Cultivating and harvesting: Traditionally, the seeds from this plant are used for
cultivation. In about three years, flowers, leaves and other parts can be harvested for
medicinal purposes. All parts can be sun-dried and packaged for sale in the local markets.
Aimually, about 6,000 kg of this plant are used in SLIM medical factories. Because of the
strong local demand, the Sri Lankan government imports about 2,000 kg of this plant
from India every year.
Other: Prehistoric evidence indicates this plant has been used as a herbal medicine;
among several African communities it is used to treat diabetes, eye disease and sexually
transmitted diseases.
64
Apart from its medicinal purposes leaves of this plant are used in 1 ) Sri Lankan cuisine,
2) as a source of nitrogen and potassium in rice fields and 3) treat leather due to its high
tannin content.
Pharmaceutical properties: Known chemical compounds are Anthraquinone glycoside,
3-hydroxy-6-8-dimethoxy-2-methyl anthraquinone- l-o--D-galactoside. 20% catechol
type tannins (-), auriculacacidin, rutin, polyphenol oxidase ascorbic acid oxidase. Keto-
alcohols emodine, -sitosterol rutin. Auricassidin, kaempferol -sitosterol
Sources: 01, 03, 04, 05, 07, 09, 18, 25, 30 & 31
Desmodium trijlorum L. (Fabaceae )
Common Names: Hin Undupiyaliya (S)
Distribution: Naturalized throughout the tropics
Ecology: The plants have a prostrate growth habit and grow in open places. The species
is wide-spread in Sri Lanka.
Use in diabetes: A drink made from dried and ground leaves is given to diabetic patients.
Other medicinal uses: Ayurveda has divided this plant into three categories according to
the size of leaves and have identified their different medicinal values. Only the smallest
leaves are used in SLIM. Leaf extracts induce breast milk production and aid digestion in
infants. Leaves are applied to heal fractured bones of children and chewing leaves
prevent dried and cracked lips. Leaf extract is used for urinary and eye diseases, digestive
problems and venomous reptile bits. It is believed that applying a mix of leaves and
dropping from a rabbit that ate these plants reduces swellings in humans. Another belief
is that walking on a patch of these plants helps to maintain good vision.
65
Cultivating and harvesting: Seeds or roots are used for cultivation. A few kilograms of
leaves can be collected within 3-4 months.
Other: This plant is widely known as the food of the rabbits.
Pharmaceutical properties: These leaves contain a high concentration of vitamin B; other
extracted chemicals are -phenylethylamines indole-3- alkylanines. Trigonelline,
stachydrine, betaine, choline, indole-3-acetic acid. Tyramine hypaphorine. Hypaphorine
N-N-dimethyltryptophan. Alkaloids amino compounds D.gangaticum. Alkaloids
nitrogen-hypaphorine, N.N-dimethyltrytryptamine, N-N-dimethyltryptamin-Nb-oxide, 5-
methoxy-N,N-di-methyltryptamine, 5-methoxy-N,N-dimethyltryptamine-Nb-oxide Nb-
nethyltetrahydroharman, 2-methyl-6-methoxy-_-carbolinium cation. Hordenine (=N,N-
dimethyltyra-mine), N-methyltryramine, candicine, -phenylethylamine choline.
Sources: 07,09, \S, 30 &3\
Hydnocarpus venenata Gaertn. (Flacourtiaceae)
Common Names: Makulla (S), Tangli Armond (E)
Distribution: Endemic to Sri Lanka
Ecology: This plant is grown throughout the country often adjacent to stream banks up to
2000 m altitude
Use in diabetes: The fruit, peel, leaves and bark are used in SLIM and extracts from all
these parts are mixed with milk to treat diabetes patients.
Other medicinal uses: A seed extract is also used to treat skin diseases and leprosy. An
extract made from the seeds is applied around the belly button of women having a
miscarriage.
66
Cultivating and harvesting: Seeds are used for cultivation.
Other: Ayurvedic books from India have mentioned another plant with similar effects
including anti-leprosy properties.
Fruits of this plant are poisonous to fish and used for fishing in rural communities. Wood
is used to build household equipment.
Pharmaceutical properties: Known chemicals are mangostin, betulinic acid, ursolic acid
acetyl, betulonic acid and sitosterol.
Sources: 03, 04, 05, 07, 09, 18, 30 & 31
Salacia reticulata Wight (Hippocrateaceae)
Common Names: Kothalahimbutu (S)
Distribution: Native to India and Sri Lanka
Ecology: This is a woody vine that is found in the forests over 1500 m altitude.
Use in diabetes: Root and bark extracts are used to treat diabetic conditions.
Consumption of high doses can cause hypoglycemia and result in cardiac arrest and
death.
Other medicinal uses: A lotion made from leaves is used for skin diseases and infections.
Cultivating and harvesting: Seeds are used for cultivation. Traditional practitioners use a
different method for cultivating this plant. Once they extract the roots or the bark, they
leave a small cut on the surface of the plant to stimulate new growth. Once mature, roots.
67
leaves and wood are harvested. Wood is sliced, sun-dried for a few days and thoroughly
ground before storing. Stored products can easily get contaminated with fungus and
should always be kept under dry conditions. Currently, 17,000 kg of this plant material is
used annually in the SLIM treatments. About 28,000 kg per year are sold in the local
markets for a variety of purposes.
Other: Because of the misbelief that this plant is endemic to Sri Lanka, exporting this
plant caused a controversy a few years ago. Due to its well-known, internationally
recognized anti-diabetic properties, it was one of the most exported medicinal plants from
Sri Lanka, but unregulated collection for exporting caused a decline in its population.
Currently conservation laws regulate its collection, transportation and merchandising.
Observations on long-term side effects have also caused a recent reduction in the
collection and utilization of this plant.
Pharmaceutical properties: Known chemicals are D:A-friedooleanan-3-one, 28-hydroxy-
D:A-friedooleanan-3-one, 3-oxo-D;A-friedooleanan-28-al, 3-oxo-D:A-friedooleanan-30-
al, D; A-friedooleanan-3,21-dione, 30-hydroxy-D:A-friedooleanan-3-one, 21ahydroxy-
D:A-friedooleanan-3-one, 3-oxo-D:A-friedooleanan-30-oic acid pristimerin.
Sources: 01, 03, 04, 05, 07, 09, 18, 22, 30 & 31
Woodfordiafruiticosa L. (Lythraceae)
Common Names: Malitha (S), Fire Flame Bush (E)
Distribution: Native to South Asia, Arab, Madagascar, Maritius (spelling), Trinidad and
South East Asia.
Ecology: This plant is found in the high altitudes of the wet zone in open grasslands and
mountain tops, often under bright sun. The species is rare in Sri Lanka.
68
Use in diabetes: Flower extracts are used to treat diabetes.
Other medicinal uses: Extracts from the flower have anti-cancer agents. Flower extract is
given to patients with diarrhea, intestinal ulcers and long-lasting external wounds.
Additionally it relieves menstrual pains and cramps. Leaf extract is applied on the
forehead to relieve headaches and applied on snake bites to stop the spread of venom.
The red flower of this plant has certain fermentation properties during the blooming
season; thus flowers are used in many traditional medicines as a preservative.
Cultivating and harvesting: Seeds are used for cultivation. Flowers are collected within
about three years for medicinal use. They should be collected early in the morning, before
insects or birds feed on the nectar. The collected flowers can be dried and stored in a dry,
cold place. Usually, 43,000 kg of dried flowers are sold aimually in local markets and
about 12,000 kg are imported from India.
Other: There is confusion among the traditional practitioners about the medicinal uses of
this species and Bauhinia racemosa (Fabaceae). Some believe both have the same
medicinal values. However, certain Ayurvedic books specifically mentions confusing the
two plants; confusion may result from the similarity in the common name "Malitha" and
"Maila."
In addition to medicinal uses, dyes are made from flowers. Wood is used to make canes
and spoons, and plants are cultivated on slopes to control soil erosion on mountains.
Pharmaceutical properties: Unknown
Sources: 01, 03, 04, 05, 07, 09, 18 & 25
69
Xylocarpus rumphii (Kostel.) Mabb. (Meliaceae)
Common Names: Konthalan (S)
Distribution: A rare plant, native to the South and South East Asia.
Ecology: This plant grows only in mangroves by the ocean. In Sri Lanka, there is only
one tree, and it is found by the Roomassala beach in the southern coastal area and thought
to be endemic to the area. Interestingly, Roomassala has many endemic species.
Traditional communities believe that Roomassala was brought to Sri Lanka from India
thousands of years ago during a war between an Indian and a Sri Lankan king.
Use in diabetes: Fruits and its peels are used to treat diabetes.
Other medicinal uses: There is not a significant amount of information on medicinal
values of this plant in Ayurvedic books. SLIM has used the fruits to treat kidney-related
disease, measles, chicken pox, mumps and certain digestive illnesses. It was also given to
patients with food and alcohol poisoning. Certain practitioners have made a medicine
called "gopalu guli" from the leaf extracts, and it was a regular household medicine for
many different illnesses, but because of its rareness, it is no longer used in any
medications.
Cultivating and harvesting: Government can take certain steps to increase the population
by educating people about its medicinal and economical values.
Other: Fruit has certain poisonous properties and hence traditional practitioners followed
a certain purification method before using it for any medicine.
Pharmaceutical properties: Unknown
Sources: 03, 04, 05, 07 & 09
70
Osbeckia octandra L. (Melastomataceae)
Common Names: Hin Bovitiya (S),
Distribution: Endemic to Sri Lanka
Ecology: Found throughout the country, often in the secondary canopy layer of forests
and in grasslands in low and high altitudes of the dry zone. The plant is also found in
home gardens, mostly because of its beautiftil purple flowers.
Use in diabetes: Immature leaves are recommended for diabetic patients to control their
blood-glucose level.
Other medicinal uses: Leaves, roots, flowers and bark have medicinal properties and are
used to make refreshing drinks. It is thought to be good for liver-related disease.
Cultivating and harvesting: Seeds and stem cuttings are used for cultivation.
Other: A related plant, with a genetic polymorphism causing the flowers to be white is
also mentioned in the SLIM and thought to have valuable medicinal properties.
Pharmaceutical properties: Unknown
Sources: 07, 09, 13, 18, 22, 29, 30, 31 & 48
71
Ficus racemosa L. (Moraceae)
Common Names: Aththikka (S), Country Fig (E)
Distribution: Native to Sri Lanka, India, Pakistan, Southern China, New Guinea, Eastern
Austrailia
Ecology: It is commonly grown adjacent to stream banks in low ahitudes of the wet zone.
Use in diabetes: Phloem extract from the root or extracts from crushed seeds are given to
diabetic patients. Liquid collected from boiling the bark and roots have anti-diabetic
properties.
Other medicinal uses: Leaves, bark, fruits, flowers and sap of this plant are used in
SLIM. Leaves disinfect external wounds and remove scars and zits. Extracts from all
parts can cure intestinal and stomach ulcers, other digestive system related conditions,
urinary infections and gonorrhea. It is also given as a pain reliever during labor.
Cultivating and harvesting: Ripe fruits are soaked in water and seeds are extracted for
cultivation. Leaves and fruits can be collected within a few years. Fruits are collected
from April through August to be sold in the local markets. Bark is only obtained from
mature trees, while collecting the bark, sap can also be collected. Only fresh sap has a
medicinal value.
Other: In some villages fruits are eaten. Myths state that it is imfortunate to see the
flowering of this tree.
Pharmaceutical properties: The sap contains caoutchouc, and the bark has gluanol
acetate, beta sitesterol, leucocyanidin-3-0-_-D-glucopyranoside, lupeol, ceryl behenate
lupeol acetate, -amyrin acetate. Other known chemical contents are 4.0-7.4%
caoutchouc 14% tannin calcium zih8% protein Lignin gluanol acetate, -sitesterol.
72
leucocyanidin-3-0_-D-glucopyranoside, Ieucopelargonidin-3-0_rhanmnopyranoside,
lupeol, ceryl behenate lupeol acetate -amyrin acetate.
Sources: 07, OS, 09, n & 13
Syzygium Cununi Skeels. (Myrtaceae)
Common Names: Madan (S), Black Plum (E)
Distribution: Native India, Sri Lanka, Southern China, Malaysia and Asia Pacific region
Ecology: Commonly grown in the forests in Sri Lanka, it is traditionally believed to be
suitable for growing by river banks to purify water. They are also grown by the coast to
reduce sand erosion.
Use in diabetes: Juice extracted from the fruits controls blood glucose level. Extraction of
seeds and bark is also known to have anti-diabetic properties.
Other medicinal uses: Bark extract is used in mouth-related diseases and for dental
problems. Leaf extract stops vomiting, and extractions from leaf buds are applied on
external wounds.
Cultivating and harvesting: Seeds are used for cultivation
Other: Unknown
Pharmaceutical properties: Known chemicals in this plant are Glucose, fructose, sucrose.
Malic acid, Gallic acid, tannins, cyaniding diglycosides, sterol, essential oil and fixed oil
linoleic acid. Oleanolic acid. Triterpnoids, acetyl oleanolic acid, eugenia-triterpenoid A
eugenia-triterpenoid B. EUagic acid, flavonoids isoquercitrin, quercetin, kaempferol
myricetin. Protein, calcium, tannin (c.19%), ellagic acid, gallic acid (1-2%), glycoside
73
(jamboline), starch (0.05%), essential oil, myricyl alcohol. Essential oil, terpenes, 1-
limonene, dipentene, sesquiterpenes of cadalane type, sesquiteqjenes of azulene type,
flavonoid glycosides, isorhamnetin-3-O-rutinoside, myricetin-3-O-glucoside myricetin -
3-0-arbinoside. Betulinic acid, -sitosterol, friedelin, ester of epi-friedelanol fatty acid
tannins, gallic acid, ellagic acid, myricetin resin
Sources: 01, 03, 04, 05, 07, 09, 15, 18 & 25
Morinda citrifolia L. (Rubiaceae)
Common Names: Ahu (S), Indian Mulberry (E)
Distribution: Native to Sri Lanka, Malaysia, The Philippines, Asia Pacific region
Ecology: This plant is mostly grown close to the beaches and in backyards of houses in
the Southern and Western Provinces of Sri Lanka. A related species, Morinda tinctoria, is
grown in Sri Lanka. It is commonly found in the Northern Province, but is not used in
SLIM.
Use in diabetes: Liquid collected from boiled fruits is used in treatment of diabetes.
Other medicinal uses: Extracts from all parts of the tree are used to treat digestive-system
illnesses, diarrhea, liver and gallbladder. Liquid extracted by grinding leaves is used as a
lotion for infections and wounds. Water taken from boiling fruits is used as a mouth
cleanser and known to be good for gum diseases.
Cultivating and harvesting: Unknown
Other: Since early history, the fruit has been used in mystic and religious activities.
Because of the unpleasant smell of the fruits, insects and birds tend to stay away from the
trees.
74
Pharmaceutical properties: Fruits contain Hexanoic, Decanoic and Octaanoic acids; the
&st two are in their inactive form while the latter is poisonous in higher doses.
Known chemicals are Octanoic acid, Hexanoic acid, Decanoic acid, glycosides
trisaccharide fatty acid. Rutin, asperulosidic acid. 2, 6-di-0-(beta-D-glucopyranosyl)-l-
0-octanoyl-beta-D-glucopyranose, rutin, asperulosidic acid, digitolutein, rubiadin 1-
methyl ether damnacanthal, iridoid lactone, morindolide, iridoid glucoside,
morofficinaloside, Anthraquinones, Iridoid glucosides, monoterpene glycoside,
phytosterols
Sources: 03, 04, 05, 07, 09, 18,30 & 31
Aegle marmelos L. (Rutaceae)
Common Names: Beli (S), Bael Fruit (E)
Distribution: A monotypic genus of India, Burma Sri Lanka and Indonesia
Ecology: In Sri Lanka, this tree grows naturally in dry monsoon areas, but can also be
found throughout the country.
Use in diabetes: Leaf extract has anti-diabetic properties.
Other medicinal uses: Every part - the roots, leaves, bark, fruits, sap, seeds, wood and
thorns - are used in SLIM. In Ayurveda, this plant is divided into two categories
according to the size of its thorns and fruits. Ayurveda has described the medicinal values
of each part of the tree and have identified different medicinal values in unripe, partially
ripe and ripe fruits. Roots prevent heart failures and other heart-related diseases. Fruit is
commonly used in Sri Lankan households to cure digestive problems. Roots, bark and
75
leaves prevent vomiting and relieve stomach aches and digestive problems caused by
bacterial infections. These extracts are also used as a pain reliever during labor. Extract
collected from boiling roots and flowers is consumed as a refreshing drink in rural
households and known to prevent urinary problems.
Cultivating and harvesting: Usually the plant is cultivated via seeds. Fruits can be
collected within five years. Trees that are about 10-15 years old yield -400 fruits per
year. These fruits can be stored for long periods by slicing and sun drying them. In the
year 2000, about 32,000 kg of fresh and dried fruits were sold in local markets for
medicinal, religious and other purposes.
Other: This plant had been used as a medicine in prehistoric communities in Sri Lanka. It
is considered a precious tree once honored by a famous Hindu god. It is believed that
growing this tree in the backyard brings peace and prosperity to the owner.
Pharmaceutical properties: It is known to contain Oleiclinoleic acides (-56.5%).
Luvangetin, pyranocoumarin. Coumarins, alkaloids, sterols, terpenes, flavonoids,
anthraquinones, lignan-glucosided, tarmins volatile oils. Coumarins, furano coumarins,
imperatorin (marmelosin) allo-imperatorin, xanthotoxin, xanthotoxol, marmesin,
psoralen, hydroxyl counmriiBlliferone, scopoletin, 0-alkylated coumarins,
aurapten, epoxyaurapten, marmin, 7-0-meltyl marmin, marminal, pyrano courmarin
aegelinol, ciimamamide type alkaloidal amides, aegeline, marmeline, tembamide, N-4-
methoxystyrylcinnamide. C-glucosylated propelargonidins. Anthraquinones, lyoniresinol,
lignan-glucosides. Anthraquinones. 7, 8-dimethoxy-l-hydroxy-2-methylanthraquinone,
6-hydroxy-l-methoxy-3-methylanthra-quinone. Monoterpene hydrocarbons, myrcene,
oxygenated monoterpenes sesquiterpenes. Volatile oidK-linalool oxide, terpene
alcohols,- ionones, terpene, gum polysaccharides. Protolimonoids, senecioate esters
of C-21-_ C-21-_ glabretals , isovalerate esters of C-21_- C-21-_ glabretals, glabretane
pentacyclic triterperes.
Sources: 01, 03, 04, 05, 07, 09, 16, 18, 25, 30 & 31
76
Curcuma longa L. (Zingiberacease)
Common Names: Kaha (S), Tumeric (E)
Distribution: Native to India, but naturalized in Sri Lanka & throughout the tropics
Ecology: This plant is found throughout the country.
Use in diabetes: Rhizome and flower extracts are used to control diabetic conditions.
Other medicinal uses: Rhizome extract prevents diarrhea, asthma and cystic fibrosis.
Cultivating and harvesting: Rhizomes with shoots can be planted. In about nine months
new rhizomes can be harvested. The traditional method of preservation is to boil the
rhizomes and air dry them under mild sun for about 12 days.
Other: Tumeric is one of the most commonly used spices in a Sri Lankan household.
People of Hindu faith consider the liquid extract of tumeric to have disinfectant
properties and believe it brings prosperity to a house. Buddhist monks use the rhizome
extracts to dye their robes yellow. A widely used spice throughout the world, it has a high
economic value in Sri Lanka.
Pharmaceutical properties: The known chemicals extracted are a-turmerone (30-32%),
arturmerone (17-26%), b-turmerone (15-18%), a-phellandrene (18.2%), 1,8-cineole
(14.6%), p-cymene (13.3%), b-curcumene (32.2-14.5%), ar-curcumene (33.2-14.5%),
xanthorrhizol (19.8-3.0%), germacrone (9.2-1 .2%)), curzerene (8.7-2.3%), curzerenone
(6.9-0.8%), monoterpenes, camphor (14.3-2.6%), a-terpineol (1.6-0.9%), isobomeol (1.6-
0.3%), and camphene (2.0-0.1%), sesquiterpenes, a-turmerone 18.9-24.2, b-turmerone
11.4-35.6, ar-turmerone 4.0-13.7, zingiberene 1.1-3.3, b-sesquiphellandrene 1.7-
2.3%monoterpenes, 1,8-cineole 0}3>^J4fidiaMie 0.3-3.4a-terpinolene, 0.1-
77
1.1% a-Turmerone, b-turmerone, ar-turmerone, b-sesquiphellandrene, a-phellandrene,
a-terpinolene .
Sources: 03, 04, 05, 07, 09, 16,18, 30 & 31
Zingibera officinale Roscoe (Zingiberaceae)
Common Names: Inguni (S), Ginger (E)
Distribution: Cultivated in tropical countries around the world including Sri Lanka
Ecology: Common throughout Sri Lanka.
Use in diabetes: Rhizome extract has anti-diabetic properties.
Other medicinal uses: This is another prominently used plant in SLIM. It is known as
''Mahaushadd" - the king of medicine - in traditional communities. Ayurveda mentions
that fresh rhizomes have different medicinal properties than dried rhizomes. Fresh
rhizomes increase production of phlegm in lungs while dried rhizomes reduce it. A
neuron stimulant, rhizome extracts are given to relieve headaches and other pains. They
are also used to prevent digestive- related diseases and asthmatic conditions. In traditional
communities it is believed that eating the rhizome increases one's ability to memorize.
Women use it to maintain a constant menstrual cycle.
Cultivating and harvesting: Mature rhizomes with shoots are used for cultivation. Grown
rhizomes can be harvested within about 9 months. If only used for food, it can be
harvested within 6 to 8 months, but should grow for full nine months if it is to be used in
medicine. Traditionally, people used a specific method to preserve ginger rhizomes. After
soaking the rhizomes in water for a day, they cover it with ash or CaCOs It is sun dried
for about 10 days and stored in a cold dry place.
78
Other: In Sri Lankan households, rhizome is used when cooking high protein meals to
help digestion.
Pharmaceutical properties: The rhizome contains three types of dehydroshogaols. a-
zingibirene, b-sesqui phellandrene, ar-curcumene, camphene, b-myrcene, a-phellandrene
copaene, a-famesene, caryophyllene germacrene.
Sources: 03, 04, 05, 07, 09, 1 8, 30 «& 3 1
Further research on all these medicinal plants is critical and may even lead to the
discovery of a novel drug to cure or prevent diabetes.
3.7 Experimental methods used to investigate anti-diabetic properties of traditional
medicinal plants
Modem approaches to testing efficacy of anti-diabetic properties in traditional medicinal
plants are usually carried under the following procedure.
Collecting and identifying the plant material.
Drying, pulverizing, sieving and storing of material.
Performing preliminary qualitative chemical analysis.
Testing in isolated organs and whole organisms.
Conducting toxicity studies.
Studying anti-diabetic properties on experimental animals.
Performing clinical trials.
Anti-diabetic activity is measured by the change in blood-sugar levels in animals induced
with a test drug. The levels are measured before and after the administration of the drug.
Experimental diabetes can be induced by any of the following methods:
• Pancreactomy i.e. surgical method
79
• Hormone Injections:
(i) Anterior pituitary extract
(ii) Corticotropins
(iii) Epinephrine
• Chemical Methods:
(i) Sodium cetoacetate
(ii) Allozan (Choudry & Vohora, 1993)
Most investigators have used mice, rats and rabbits as experimental animals. Alloxan
induced diabetes has been the most commonly used methods in these animals. They are
usually given about 150-200 mg of Alloxan per one kilogram of body weight by rapid
intravenous injections; this partially degenerates beta cells in Langerhan islets. To
prevent initial hyperglycemia in animals, 2.5 g/kg of glucose is fed. In about 4-7 days
permanent diabetes is induced.
Researches in South Asia have used various methods to investigate the blood-glucose
level in diabetes-induced animals. Glucose uptake by Rat Diaphragm Method, a
comparison with standard hypoglycemic agents and methods for Elucidation of
Mechanism of Action are some techniques to measure bloods-glucose levels. Once
traditional medicinal plant extracts are proven to be effective in controlling blood-glucose
levels in experimental animals, clinical trials are conducted. These clinical trials are
carried out under strict hospital supervision (Choudry & Vohora, 1993)
Through carefully conducted research on SLIM, vast amount of knowledge can be gained
on therapeutic methods for many illnesses such as diabetes. These investigations, apart
from the benefit towards discovering new drugs, might lead to a wider recognition of
SLIM locally and internationally.
80
3.8 Current Medicinal Plant Conservation Efforts in Sri Lanka
Historical evidence shows that eariy kings in Sri Lanka, urged the cultivation of fruits
vegetables and herbs for animals and humans (Silva, 1984). Thus from historic times Sri
Lankans have recognized the importance of conserving plants and biodiversity.
In 1998, with the encouragement from the CBD (Conservation of Biological Diversity),
the Sri Lankan goverimient indicated interest in conservation and sustainable use of
medicinal plants. These include:
• In-situ conservation- the Sri Lankan government have established five
medicinal plant conservation areas adjacent to existing natural forests that are
habitats to certain threatened medicinal plants. These areas are Bibile and
Ritigala (Dry Zone), Rajawaka and Naula (Intermediate Zone) and kanneliya
(Wet Zone), each of which representing a different ecological zone of Sri
Lanka. The project aims to involve communities living in these areas to
promote conservation and sustainable use of plants. Each site contains a
medicinal plant garden, a medicinal plant processing center for the use by
local communities, an ayurvedic dispensary and an information center.
• Ex-situ conservation - Promoting the establishment of nurseries, home
gardens and plantations, and supporting propagation and agronomic research
• By providing information and institutional support including promotion of an
appropriate legal and policy environment (Mahindapala, 2004: Palliyagedara,
2004: Mudalige, 2004)
A Convention on International Trade in Endangered Species of Wild Fauna and Flora
(CITES) revealed that the biggest threat to endangered spices including medicinal plants
in Sri Lanka and other countries is the destruction of their natural habitats for industrial
purposes (Joseph &, Mahindapala, 2004). CITES described commercial exploitations are
81
the second largest threat to the survival of these species. Certain medicinal plants species
are prone to extinction due to unlimited exploitation, especially for exportation. For a few
dollars, which is worth a lot of money in Sri Lanka, a villager may agree to collect any
amount of medicinal plants from the forests. Another threat to these plants is the lack of
public awareness about medicinal value of these plants (Pilapitiya, 1994) The
government and the citizens must safeguard this heritage while providing a better health
care system to the world (Samarasinghe, 1994).
Currently almost all the medicinal plants used in SLIM are cultivated at Peradeniya and
Haggala Botanical Gardens and at herbal gardens in Bandaranayake Ayurveda Research
Center, Bathgoda, Pallekale, Girandurukotte and HaldummuUa (Joseph &, Mahindapala,
2004).
The best place to collect medicinal plants or plant material is the primary forest.
Traditionally, these plants are believed to contain the best medicinal properties.
Unregulated collection could be harmful to the natural growth cycle of the plant and its
environment, especially if collected in mass quantities. While it is better to cultivate these
plants, it is a concern that use of pesticides and herbicides could reduce medicinal
properties (Mudalige, 2004). Hence organic farming may be better suited for the
cultivation of medicinal plants. In Sri Lanka, unsupervised use of chemicals in farming
has damaged many herbal medicinal plants. Some herbicides may eradicate certain
plants, while some chemicals cause harmful effects. Currently, the Sri Lankan
Agriculture Department combined with the Ayurvedic Department has introduced certain
plans and procedures on cultivating and conserving medicinal plants. They have
encouraged local farmers to follow some of the methods used in traditional Sri Lankan
agriculture and not to disregard them simply because they are "traditional." For example,
Ayurveda suggests collecting only the roots growing towards the west side of the plant.
This actually reduces destruction since roots from other sides are still protected
(Marasinghe, 2000: Gunasekara, 2002).
82
Most of the plants used in Ayurveda or SLIM have a high economic value due to their
medicinal properties. However, the collection of material from these plants is very
tedious and labor intensive. Since labor is much cheaper in India than Sri Lanka, India
has been one of the major providers of certain medicinal plants to the international
community (Gunasekara, 2002).
Illegal exportation of medicinal plants is another unfortunate circumstance in the country.
Sri Lankan customs have detected several times in which Salacia reticulata Wight
(Kothala Himbutu (S): Hippocrateaceae) plants have been attempted to be smuggled out
of the country. It is also believed that Coscinium fenestratum (Gaertn.) Colebr (Venival
(S): Menispermaceae) and Rauvolfia serpentina (L.) Benth.ex Kurz (Ekaveriya (S):
Apocynaceae), two protected endangered plants, are often smuggled out of the country.
This situation poses a major threat to the economic value of medicinal plants of Sri
Lanka, especially of those that are endemic (Marasinghe, 2000: Gunasekara, 2002:
Mahindapala, 2004).
Certain plants have become almost extinct from the uncontrolled collection due to the
high demand from pharmaceutical companies in the western countries. There is also a
huge revenue loss for the Sri Lankan government as some of these plants are sold in the
black market. As the mass collection and exportation for very low prices to the foreign
markets continue, it causes a detrimental environmental and economical effect to the
country. Hence, there should be a carefully conducted cost and benefit analysis on the
current situation and repay any damages caused to the traditional communities.
Additionally, botanists believe that plants may have lost their medicinal properties
because of the over-exploitation of their gene pool. They suspect that genetic drift and
degradation of biodiversity will be the ultimate result of this over-exploitation
(Marasinghe, 2000). Another major threat to the natural habitats of medicinal plants is the
rapidly increasing human population. Most of the medicinal plants are found in the wet
zone of the country, where most of the Sri Lanka's population is concentrated. Botanists
fear that researchers or naturalists in disguise are collecting important and endangered
plants even from the conserved areas for exportation. Even though there is pressure from
83
international and local organizations to conserve and protect medicinal plants, financial
hardship in rural communities in Sri Lanka is a major obstacle to prevent over-
exploitation of plants. The lack of knowledge on medicinal plants and their habitats
among policy makers, conservationists, students and teachers, villagers, farmers and
other general public is another obstacle that needs to be addressed by the government
(Marasinghe, 2000: Gunasekara, 2002: Mahindapala, 2004: Ministry of Agriculture,
1995).
Enforcing the law, educating the public and regular monitoring of natural habitats for
medicinal plants would provide a better future not only to the SLIM, but to the
biodiversity of the country (Marasingha, 2000). It is also important to urge those who
practice indigenous medicine in rural communities to pass their knowledge on plants to
the next generation.
3.9 Conclusions
With the increasing attention from developed world towards ethnomedicine and
ethnobotany, SLIM foresee a bright future as it carries a vast knowledge on plant
medicine. Production of higher quality drugs and standardizing them under the
supervision of Indigenous Medicine Drug Corporation of Sri Lanka would attract more
people to use these medications. Collaboration of Western doctors and researchers with
the traditional practitioners will develop this medication system to implement better
human healthcare in the future (Simpson &. Ogorzaly, 2001). It is important to preserve
the indigenous knowledge retained through generations while also conserving the plants
for future medicinal use and research.
84
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