Anti-diabetic Effect of Elephant-foot Yam (Amorphophallus paeoniifolious (Dennst.) Nicolson) in Streptozotocin-induced Diabetic Rats

Abstract

In the present study, the effect of the acetone extract of elephant-foot yam (Amorphophallus paeoniifolious (Dennst.) Nicolson) at 0.1 and 0.25% in the diet of streptozotocin-induced male Wistar diabetic rats was studied. The study involved a comparison between control and diabetic groups: starch-fed control/diabetic (SFC/SFD), 0.1% acetone extract fed control/diabetic (AEFC 0.1 /AEFD 0.1), 0.25% acetone extract fed control/diabetic (AEFC 0.25 /AEFD 0.25) and aminoguanidine fed control/diabetic (AFC/AFD). The rats were examined for water intake, diet intake, urine output, gain in body weight, urine sugar, fasting blood sugar (FBS) and glomerular filtration rate (GFR). A concentration-dependent amelioration of the diabetic status was observed with respect to all the above studied parameters. FBS of AEFD 0.1 and AEFD 0.25 groups showed a 23% and 37% reduction, respectively whereas the AFD group showed a 45% reduction relative to the SFD group. The GFR of experimental rats in AEFD 0.1 and AEFD 0.25 groups showed a 28% and 41% reduction, respectively whereas the AFD group showed a 54% reduction compared to the SFD group. The results clearly indicate that the acetone extract of elephant foot yam is an effective anti-diabetic agent for streptozotocin-induced diabetic rats.

Full text

Received: 28 March, 2012. Accepted: 29 June, 2012. Original Research Paper
International Journal of Biomedical and Pharmaceutical Sciences ©2013 Global Science Books
Anti-diabetic Effect of Elephant-foot Yam
(Amorphophallus paeoniifolious (Dennst.) Nicolson)
in Streptozotocin-induced Diabetic Rats
Harshavardhan Reddy Arva1 • Jamuna J. Bhaskar2 •
Paramahans V. Salimath2 • Aradhya Somaradhya Mallikarjuna1*
1 Departme nt of Fr uit and Vegetable Technology, Cent ral Food Technolo gical Resear ch Instit ute (Council of S cientifi c and Industrial Research),
Mysore, Karnataka , 570 020 India
2 Department of Biochemistry and Nutrition, Central Food Technological Research Institute (Council of Scientific and Indust rial Research), Mysore, Karnataka, 570 020 India
Corresponding author: * aradhyasm@y ahoo.co.in
ABSTRACT
In the present study, the effect of the acetone extract of elephant-foot yam (Amorphophallus paeoniifolious (Dennst.) Nicol son) at 0.1 and
0.25% in the diet of streptozotocin-induced male Wistar diabetic rats was studied. The study involved a comparison between control and
diabetic groups: starch-fed control/diabetic (SFC/SFD), 0.1% acetone extract fed control/diabetic (AEFC0.1/AEFD0.1), 0.25% acetone
extract fed control/diabetic (AEFC0.25/AEFD0.25) and aminoguanidine fed control/diabetic (AFC/AFD). The rats were examined for water
intake, diet intake, urine output, gain in body weight, urine sugar, fasting blood sugar (FBS) and glomerular filtration rate (GFR). A
concentration-dependent amelioration of the diabetic status was observed with respect to all the above studied parameters. FBS of
AEFD0.1 and AEFD0.25 groups showed a 23% and 37% reducti on, respectively whereas the AFD group showed a 45% reduction relative to
the SFD group. The GFR of experimental rats in AEFD0.1 and AEFD0.25 groups showed a 28% and 41% reduction, respectively whereas
the AFD group showed a 54% reduction compared to the SFD group. The results clearly indicate that the acetone extract of elephant foot
yam is an effective anti-diabetic agent for streptozotocin-induced diabetic rats.
_____________________________________________________________________________________________________________
Keywords: fasting bl ood sugar, glomerular filtration rate, urine sugar
INTRODUCTION
Diabetes mellitus is an endocrine disorder characterized by
inappropriate hyperglycemia resulting from defects in insu-
lin secretion, insulin action, or both (Chandra et al. 2004;
Frode and Medeiros 2008; Wadkar et al. 2008). It disturbs
the metabolism of carbohydrates, fats, proteins and electro-
lytes leading to series of secondary complications like dia-
betic nephropathy, neuropathy, retinopathy, polyurea, poly-
phagia, polydypsia, ketosis and also cardiovascular dis-
orders (Rohrbach and Martin 1982; Shimomuna and Spiro
1987; Kumar and Clark 2002; Oyedemi et al. 2011). The
incidence of diabetes is on the rise affecting 4% of the
population worldwide and is expected to increase to 5.4%
by 2025, and it is estimated that India, China and the United
States will have the largest number of people with diabetes
by 2030 (Wild et al. 2004; Chung et al. 2011).
Plants continue to play an important role in the treat-
ment of diabetes, and they could fill the gap that exists to
conventional treatments in different parts of the world.
Antidiabetic agents from plants are considered to be less
toxic with minimum or no adverse side effects (Rao et al.
1999; Pari and Umamaheswari 2000; Sakthi et al. 2010;
Oyedemi et al. 2011). The World Health Organization
(WHO) has recommended the evaluation of natural prod-
ucts from plant sources for the treatment and control of dia-
betes (Day 1998).
Eleph ant foot yam (Amorphophallus paeoniifolious
(Dennst.) Nicolson syn. Amorphophallus campanulatus), is
an edible tuber crop grown in tropical and subtropical
regions, particularly in South-east Asia. It is commercially
cultivated in India, Sri Lanka, China, Malaysia, Thailand,
Indonesia and the Philippin es and in tropical region s of
Africa. The corm of elephant foot yam is mainly used as a
vegetable in the preparation of various delicious cuisines
and is a major ingredient in indigenous Ayurvedic prescrip-
tions (Misra et al. 2002; Srinivas and Ramanathan 2005;
Angayarkanni et al. 2007). It is restorative, carminative,
stomachic and tonic. Fresh yam acts as an acrid stimulant
and expectorant (Chopra et al. 1958; Ghani 1998). The
tuber is useful in the treatment of piles, acute rheumatism
(Chopra et al. 1958; Yusuf et al. 1994), enlarged spleen,
abdominal tumors, boils, asthma (Yusuf et al. 1994), abdo-
minal pain, dyspepsia and elephantiasis (Kirtikar and Basu
1994; Kailash et al. 2007). The fermented juice of petioles
is used to treat diarrhea whereas seeds are used to treat
rheumatic swelling (Chatterjee and Pakrashi 2001).
The major sugars identified from tuber are glucose,
galactose and rhamnose while flavonoids, phenols, couma-
rins, terpenoids, sterols, tannins, steroids and alkaloids have
also been reported (Harborne 1984; Shilpi et al. 2005; Nata-
raj et al. 2009; Yadu and Ajoy 2010). Amblyone (a triter-
penoid) and 3,5-diacetylambulin (a flavonoid) have been
isolated from tubers (Khan et al. 2008a, 2008b). The tuber
is reported to have antiprotease (Prathibha et al. 1995),
analgesic (Shilpi et al. 2005), antibacterial, antifungal, cyto-
toxic (Angayarkanni et al. 2007; Khan et al. 2007, 2008b),
central nervous system depressant (Dey et al. 2009), anti-
inflammatory (Dey et al. 2010), anthelmintic (Ramalingam
et al. 2010), immunomodulatory (Tripathi et al. 2010), anti-
oxidant (Angayarkanni et al. 2010) and hepatoprotective
activity (Shastry et al. 2010; Surendhra et al. 2011),
There are no scientific reports available on the antidia-
betic effect of elephant foot yam. Hence, the present inves-
tigation was undertaken to study the effect of acetone ex-
tract of elephant foot yam in streptozotocin induced diabetic
rats.
®

International Journal of Biomedical and Pharmaceutical Sciences 7 (1), x-y ©2013 Global Science Books
MATERIALS AND METHODS
Plant material
Fresh and healthy corms of elephant-foot yam (var. Gajendra)
were procured from the local market of Mysore, Karnataka, India.
The corm was identified and authenticated by Prof. Shivamurthy,
Head, Department of Botany, University of Mysore, Mysore, India.
The procured corms were washed, sliced into cubes and dried in a
hot air oven at 40°C for 24 h and powdered using a 60 mesh in an
apex-comminuting mill (Apex Constructions, London).
Chemicals
Streptozotocin, aminoguanidine and p-dinitrosalicylic acid were
obtained from Sigma Chemicals Co., (St. Louis, USA). GOD/POD
(Glucose oxidase (E.C 1.1.3.4)-Peroxidase (E.C 1. 11.1.7) and
creatinine kits were purchased from M/S Span Diagnostics Ltd.,
Surat, India. Folin–Ciocalteu reagent and all the organic solvents
(AR grade) used for extraction were purchased from E. Merck,
Mumbai, India. All other chemicals used were of analytical grade.
Preparation of corm extracts
The dri ed powder of elephant-foot yam was serially extracted wit h
solvents (1:10, w/v) of increasing polarity, namely hexane, chloro-
form, ethyl acetate, acetone and methanol, on a shaker at 100 rpm
for 48 h at room temperature. The extracts were filtered and con-
centrated by using a rotary evaporator (Buchi Rota Vapor R-124).
The concentrated extracts were lyophilized and stored at -18°C in
a refrigerator. The acetone extract was used for the experiment
because of its hi ghest total phenol and flavonoid content when
compared with other extracts (Table 1).
Preparation of diet
Acetone extract powder at 0.1 and 0.25% and aminoguanidine at
0.05% were incorporated to replace an equivalent amount of corn
starch in AIN-76 basal diet containing 63.5% corn starch, 20%
protein, 10% fat, 3.5% AIN-76 mineral mix, 1% AIN-76 vitamin
mix, 0.2% choline chloride (Bieri et al. 1997) and was stored at
4°C.
Animals and induction of diabetes
The present study had the approval (Approval document number
IAEC-92/06) of the Institutional Animal Ethical Committee,
CFTRI, Mysore, India. Male Wistar rats (breed OUTB-Wistar,
IND-CFT (2C)), weighing 140-160 g were obtained from the
Animal House, Department of Biochemistry, Central Food Tech-
nological Research Institute (CFTRI), Council of Scientific and
Industrial Research (CSIR), India, and housed in individual steel
cages at the animal house facility of the institute.
Rats were divided into eight groups: starch fed control (SFC)
and diabetic (SFD), acetone extract at 0.1% fed control (AEFC0.1)
and diabetic (AEFD0.1), acetone extract at 0.25% fed control
(AEFC0.25) and diabetic (AEFD0.25), and aminoguanidine fed con-
trol (AFC) and diabetic (AFD). Each of the control groups had 6
rats and diabetic groups had 14 rats. Rats were rendered diabetic
by a single intraperitonial (i.p.) injection of streptozotocin at 45
mg/kg body weight in freshly prepared citrate buffer (pH 4.5, 0.1
M) (Jamuna et al. 2010). The animals had free access to water and
diet, which was in powder form. The rats were sacrificed after 12
weeks of induction of diabetes.
Collection of blood and urine samples
Blood was drawn, after overnight fasting, from the retro-orbital
plexus of the rats either during the experiment or at the end of the
experiment from the heart, after sacrificing them under ether
anesthesia. Blood was collected in tubes with heparin sodium (20
U/ml blood) prepared in 0.9% saline. For urine collection, rats
were kept in metabolic cages for a period of 24 h and urine was
collected under a layer of toluene (Jamuna et al. 2010).
Determination of water intake, diet intake, body
weight, urine volume and urine sugar
Water intake, diet intake, body weight, urine volume and urine
sugar were monitored biweekly. Water intake, diet intake, body
weight and urine volume were measured gravimetrically. The con-
tent of reducing sugar pr esent in urine was measured by the 3, 5-
dinitrosalycilic acid method (Miller 1959). 10-100 µl of sample
was taken and diluted to 1ml with distilled water. To this, 1 ml of
dinitrosalicylic acid (DNS) reagent was added and boiled for 10
min in a water bath. The solution is cooled and diluted with 4ml of
distilled water. Intensity of colour was measured at 540nm. Dex-
trose was used as a standard (Miller 1959).
Determination of fasting blood sugar and
glomerular filtration rate
Fasting blood sugar (FBS) and glomerular fi ltration rate (GFR)
were analyzed at the end of 12 weeks. Rats were fasted overnight
to determine the FBS. FBS was measured by glucose oxidase
method (Hugget and Nixon 1957) using glucose oxidase/peroxi-
dase kit. Creatinine was estimated by Bower’s method in blood
and urine (24 h collection) using creatinine kit (Bowers 1980).
GFR was determined by estimating creatinine level in urine and
plasma (Yokozawa et al. 1996) using the following formula:
GFR (ml/min) = Urinary creatinine (mg/dl) × urine volume (ml) ×
1000 (g)/Plasma creatinine (mg/dl) × body weight (g) × 1440
(min)
Statistical analysis
Values are presented as mean ± SD in all control and diabetic
groups. Data were analysed by one-way analysis of variance
(ANOVA) using Micr osoft Excel XP® (Microsoft Corp., USA),
and post-hoc mean separations were performed by Duncan’s
Multiple Range Test (DMRT) at P < 0.05 (Harter 1960).
RESULTS AND DISCUSSION
Effect of acetone extract of elephant foot yam on
water intake, diet intake, body weight and urine
output in control and diabetic rats
Higher intake of water during diabetes was reported (Shetty
et al. 2004). Table 2 shows the effect of acetone extract of
elephant foot yam on water intake (ml/24hr) in control and
diabetic rats. There was no significant (P > 0.05) difference
in water intake of control groups. Consumption of water
was higher in diabetic rats compared to control rats. Ace-
tone extract at 0.1% (AEFD0.1) and 0.25% (AEFD0.25) fed
diabetic groups and aminoguanidine fed diabetic group
showed significant (P < 0.05) reduction in intake of water.
Table 3 shows the effect of acetone extract of elephant
foot yam on diet intake (g/24hr) in control and diabetic rats.
Diabetic rats consumed higher quantity of diet compared to
control rats. Significant (P < 0.05) reduction in diet intake
was observed in extract incorporated and aminoguanidine
fed diabetic groups. There was no significant (P > 0.05)
difference in diet intake between starch-fed control and ace-
tone extract fed control groups.
Severe loss in body weight is characteristic feature of
STZ-induced diabetes (Chen and Ianuzzo 1982). Body
Tab le 1 Total phen ol and flavonoid cont ent of ele phant foot yam extra cts.
Elephant foot
yam extracts Total phenols
(mg Gallic acid
equivalents/g of extract)
Total f lavo noids
(mg Catechin
equivalents/g of
extract )
Hexa ne - -
Chloroform - -
Ethyl acetate 27.40 6.66
Acetone 866.27 585.70
Methanol 50.30 32.14

Anti-diabetic effect of elephant-foot yam. Harshavardhan et al.
weight of control rats increased over a period of time and
there was not much difference in body weight gain among
the control groups (Table 4). On the other hand gain in
body weight of diabetic rats was too low and the weight
gain of AEFD0.1 and AEFD0.25 groups was significant (P <
0.05) compared to SFD group. Aminoguanidine fed diabetic
group showed significant (P < 0.05) gain in body weight
over SFD group.
Table 5 shows the effect of acetone extract of elephant
foot yam on urine output (ml/24hr) in control and diabetic
rats. The urine output was 5-8 ml/day in all the control
groups. The polyuria was pronounced in SFD group and
volume of urine excreted was about 55 ml/day at the termi-
nation of the experiment. The reduction in polyuria was sig-
nificant (P < 0.05) in AEFD0.1 (39 ml/day), AEFD0.25 (32
ml/day) and AFD (31 ml/day) groups.
Tab le 2 Effect of acetone extra ct of elephant foot ya m on water intake (ml/24 h) in control and diabetic ra ts.
Duration (weeks)
Experimental Group II IV VI VIII X XII
SFC 17.8±2.05a 20.5±2.28a 23.7±2.27a 25.3±2.47a 28.6±2.51a 30.6±2.32a
SFD 80.2±8.22e 101.7±11.2e 128.5±12.3e 147.6±12.4e 158.2±10.6e 167.9±11.8 e
AEFC0.1 18.5±2.03a 20.8±2.17a 24.9±2.42a 27.6±2.24a 29.4±2.43a 31.7±2.16a
AEFD0.1 69.4±8.46d 80.6±12.6d 94.8±11.41d 109.5±12.4d 11 5.4±11.89d 126.3±12.14d
AEFC0.25 18.4±2.09a 20.9±2.63a 22.8±2.56a 24.2±2.23a 27.3±2.13a 29.8±2.14a
AEFD0.25 58.3±9.3c 69.5±10.1c 76.8±9.05c 88.7±12.5c 95.6±12.2c 103.4±11.4 c
AFC 16.9±2.63a 19.7±2.49a 22.3±2.22a 25±2.58a 27.9±2.38a 32.1±2.18a
AFD 52.6±9.66b 61.5±9.61b 68.4±8.52b 76.7±10.17b 80.8±10.6b 91.3±9.87b
SFC: s tarch fed cont rol, SFD: starch fed diab eti c, AEFC0.1: ele phant foot yam extract at 0.1% fed cont rol, AEFD0.1: ele phant foot yam extract at 0. 1% fed diabetic, AEFC0.25:
elepha nt foot yam extr act at 0.25% fe d control, AEFD0.25: elep hant foot yam extract at 0.25% fed diabetic, AFC: amino guanidine fed cont rol, AFD: aminoguani dine fed
diabetic. Values are expressed as mean ± Standard Devi ation (SD) of control and di abetic groups. Value of ‘n’ is 6 for control groups and 8 fo r diabetic groups. Values with
different alphabets in the same col umn indic ate signific ant differe nces among gr oups at P < 0.05
Tab le 3 Effect of acetone extrac t of elephant foot yam on diet intake (g/24 h) in contr ol and diabetic rats.
Duration (weeks)
Experimental Group II IV VI VIII X XII
SFC 12.8±0.78a 13.9±0.88a 14.4±0.84a 15.2±0.54a 16.6±0.71a 17.8±0.82a
SFD 19.2±1.24e 21.5±1.69e 23.3±1.49e 26.1±1.13e 29.3±1.12e 32±1.21e
AEFC0.1 13.3±1.08a 14.3±0.95a 14.8±1.09a 15.6±0.9a 16.3±1.02a 17.2±0.85a
AEFD0.1 17.6±0.79d 20±0.96d 21.3±1.42d 22.8±1.24d 24.1±1.23d 25.9±1.21d
AEFC0.25 13.7±1.02a 14.1±0.87a 15.1±1.12a 16.1±0.65a 16.9±0.94a 18.1±0.78a
AEFD0.25 16.8±1.32c 18.2±1.44c 19.7±1.45c 20.2±1.56c 21.4±1.64c 22.3±1.62c
AFC 13.6±0.91a 14.1±0.95a 14.9±1.22a 15.6±1.14a 16.9±0.91a 17.4±0.98a
AFD 15.4±1.53b 16.3±0.94b 16.9±1.28b 17.4±1.12b 18.6±1.74b 19.8±1.36b
SFC: s tarch fed cont rol, SFD: starch fed diab eti c, AEFC0.1: ele phant foot yam extract at 0.1% fed cont rol, AEFD0.1: ele phant foot yam extract at 0. 1% fed diabetic, AEFC0.25:
elepha nt foot yam extr act at 0.25% fe d control, AEFD0.25: elep hant foot yam extract at 0.25% fed diabetic, AFC: amino guanidine fed cont rol, AFD: aminoguani dine fed
diabetic. Values are expressed as mean ± Standard Devi ation (SD) of control and di abetic groups. Value of ‘n’ is 6 for control groups and 8 fo r diabetic groups. Values with
different alphabets in the same col umn indic ate signific ant differe nces among gr oups at P < 0.05
Tab le 4 Effect of acetone extract of elephant foot yam on body weight (g) in control and diabetic rats
Duration (weeks)
Experimental Group 0 II IV VI VIII X XII
SFC 157.6±6.72 208.6±8.8a 254.2±9.5a 269.5±11.7a 296.0±12.9a 315.5±15.9a 324.1±18.41a
SFD 162.4±7.84 172.4±9.5d 175.3±11.4e 180.8±12.1e 192.2±12.8e 203.8±13.54e 212.5±14.1e
AEFC0.1 155.6±6.76 206.3±8.6a 251.6±8.2a 264.4±9.4a 294.0±10.8a 316.6±13.4a 330.2±18.8a
AEFD0.1 158.1±7.29 179.1±8.2cd 193.8±9.82d 213.6±10.1d 224.5±11.4d 243.2±12.8d 257.4±13.5d
AEFC0.25 155.3±5.93 212.3±7.47a 253.5±8.21a 271.5±9.15a 291.8±10.9a 313.1±12.3a 326.0±15.96a
AEFD0.25 159.7±6.43 182.8±8.83bc 200.8±9.91c 225.1±10.4c 248.1±12.3c 263.0±13.8c 274.8±14.65c
AFC 157.5±6.87 214.5±9.82a 256.1±10.1a 274.2±11.7a 292.7±12.3a 311.3±13.7a 329.6±16.8a
AFD 162.6±6.63 189.2±9.7b 217.3±10.8b 239.8±11.7b 264.6±13.8b 278.1±14.9b 289.2±15.1b
SFC: s tarch fed cont rol, SFD: starch fed diab eti c, AEFC0.1: ele phant foot yam extract at 0.1% fed cont rol, AEFD0.1: ele phant foot yam extract at 0. 1% fed diabetic, AEFC0.25:
elepha nt foot yam extr act at 0.25% fe d control, AEFD0.25: elep hant foot yam extract at 0.25% fed diabetic, AFC: amino guanidine fed cont rol, AFD: aminoguani dine fed
diabetic. Values are expressed as mean ± Standard Devi ation (SD) of control and di abetic groups. Value of ‘n’ is 6 for control groups and 8 fo r diabetic groups. Values with
different alphabets in the same col umn indic ate signific ant differe nces among gr oups at P < 0.05
Tab le 5 Effect of acetone extract of elephant foot yam on urine output (ml/24 h) in control and diabetic rats.
Duration (weeks)
Experimental Group II IV VI VIII X XII
SFC 5±1.0a 5±0.5a 5.5±0.5a 5±1.0a 5.5±0.5a 6.1±0.3a
SFD 29±5.13e 30±4.73e 38.5±3.2e 42.6±2.9e 47.1±2.38e 55.3±3.12e
AEFC0.1 4.5±0.5a 7±1.0a 5.5±0.5a 5±0.5a 8±2.0a 5.1±0.5a
AEFD0.1 27±3.64d 26.2±5.02d 29.8±3.45d 33.5±2.06d 35.3±3.93d 38.6±4.32d
AEFC0.25 7±1.0a 5.5±0.5a 6.5±1.5a 6.5±1.5a 6.5±1.5a 6±0.3a
AEFD0.25 25.2±4.17c 26.5±4.04c 26.8±5.32c 24.5±2.85c 27.3±1.95c 31.8±2.58c
AFC 4.5±0.5a 5.5±0.5a 7±1.0a 4.5±0.5a 6.5±0.5a 5±0.5a
AFD 20.1±4.92b 22.5±3.1b 23.7±2.74b 24.8±2.31b 28.7±3.29b 30.5±3.94b
SFC: s tarch fed cont rol, SFD: starch fed diab eti c, AEFC0.1: ele phant foot yam extract at 0.1% fed cont rol, AEFD0.1: ele phant foot yam extract at 0. 1% fed diabetic, AEFC0.25:
elepha nt foot yam extr act at 0.25% fe d control, AEFD0.25: elep hant foot yam extract at 0.25% fed diabetic, AFC: amino guanidine fed cont rol, AFD: aminoguani dine fed
diabetic. Values are expressed as mean ± Standard Devi ation (SD) of control and di abetic groups. Value of ‘n’ is 6 for control groups and 8 fo r diabetic groups. Values with
different alphabets in the same col umn indic ate signific ant differe nces among gr oups at P < 0.05

International Journal of Biomedical and Pharmaceutical Sciences 7 (1), x-y ©2013 Global Science Books
Effect of acetone extract of elephant foot yam on
urine sugar, fasting blood sugar and glomerular
filtration rate in control and diabetic rats
There was no significant (P > 0.05) difference in urine
sugar among the control groups (Table 6). The rats in starch
fed diabetic group excreted 9 g of urine sugar per day,
during last week of the experiment. Decrease in urine sugar
excretion by about 35 and 55% was observed in AEFD0.1
and AEFD0.25 groups respectively, whereas in AFD group a
decrease of 65% was observed and the results were statis-
tically significant (P < 0.05) from SFD group.
Streptozotocin causes damage to the β-cells of pancreas
resulting in reduction in insulin secretion and increased
blood glucose (Halliwell and Gutteridge 1985; Zhang and
Tan 2000; Kumar et al. 2011). The fasting blood sugar of all
control groups on 12th week was 106-115 mg/dl and was not
significantly (P > 0.05) different from one another (Fig. 1),
whereas, fasting blood sugar in starch fed diabetic group
was 376 mg/dl. Fasting blood sugar of AEFD0.1 and
AEFD0.25 groups showed 23 and 37% reduction, respec-
tively, whereas, AFD group showed 45% reduction in com-
parison to SFD group.
In diabetic condition disorder in renal glomerulus was
reported (Michael Brownlee 2001). The glomerular filtra-
tion rates were significantly (P < 0.05) higher in diabetic
groups (Fig. 2), when compared to control groups (1.1-1.25
ml/min). The GFR of SFD was much higher (6.3 ml/min)
than the AEFD0.1 group (4.5 ml/min) and AEFD0.25 group
(3.7 ml/min). The AEFD0.1 group showed 28% reduction
and AEFD0.25 group showed 41% reduction, whereas the
AFD group showed 54% reduction in GFR at the end of the
experiment, when compared to SFD group.
Streptozotocin-induced diabetic rat is widely used ani-
mal model to study the bioactivity of antidiabetic agents
(Henriksen et al. 2000). Streptozotocin generates oxygen
free radicals in the body, which are involved in pathogene-
sis and various secondary complications of diabetes (Halli-
well and Gutteridge 1985; Baynes 1991; Bonnefont-Rous-
selot et al. 2000; Rahimi et al. 2005; Naveen and Khanum
2010). Prevention and control of secondary complications
associated with diabetes has become one of the important
areas in biomedical research. In this context, dietary
management of diabetes along with other means of control
is of prime significance.
A diet rich in phytochemicals is reported for anti hyper-
glycemic activity (Loizzo et al. 2011). Investigations rev-
ealed that regular intake of fruits and vegetables rich in
phytochemicals lowered the risk of diabetes (Boyer and Liu
2004; Harunobu et al. 2009). Fruits like apple, jamun,
karonda and vegetables like bitter gourd, garlic, pseudostem
of banana and purple yam exhibited good antidiabetic pot-
ential (Day et al. 1990; Platel and Srinivasan 1997; Khan
and Safdar 2003; Mallick et al. 2006; Young et al. 2007;
Adyan thaya et al. 2010; Jamuna et al. 2011; Maithili et al.
2011; Prakash et al. 2011).
Members of the Amorphophallus genus are traditionally
used in diet for the control of diabetes. Hypoglycemic effect
of Amorphophallus konjac was proved experimentally
(Mao and Gu 1999). In the present investigation, feeding of
acetone extract of elephant foot yam at 0.1% and 0.25%
level in diet to streptozotocin-induced diabetic rats showed
beneficial effects with respect to diet intake, water intake,
gain in body weight, urine output, urine sugar, fasting blood
sugar and glomerular filtration rate. It is evident from the
results that there is gradual amelioration over the experi-
mental period in the diabetic status of AEFD0.1, AEFD0.25
and AFD groups when compared to SFD group. Similar
results were reported by using bitter gourd and quercitin
(Shetty et al. 2004, 2005a).
The anti-diabetic effect of acetone extract of elephant
foot yam may be attributed to its bioactive substances like
Tab le 6 Effect of acetone extract of elephant foot ya m on urine sugar (g/24 h) in control and diabetic rats.
Duration (weeks)
Experimental Group II IV VI VIII X XII
SFC 0.04±0.01a 0.07±0.005a 0.08±0.005a 0.01±0.005a 0.06±0.002a 0.03±0.007a
SFD 3.91±0.52e 4.42±0.68e 6.08±0.9e 7.99±0.79e 8.83±0.35e 9.25±0.93e
AEFC0.1 0.023±0.005a 0.05±0.015a 0.07±0.005a 0.03±0.004a 0.08±0.001a 0.05±0.002a
AEFD0.1 3.71±0.65d 4.19±0.74d 4.92±0.81d 5.22±0.48d 5.81±0.66d 6.03±0.81d
AEFC0.25 0.085±0.005a 0.08±0.011a 0.09±0.004a 0.02±0.009a 0.07±0.011a 0.063±0.008a
AEFD0.25 3.15±0.61c 3.72±0.84c 4.12±1.01c 4.43±0.46c 4.35±0.61c 4.18±0.73c
AFC 0.073±0.001a 0.05±0.001a 0.03±0.003a 0.03±0.002a 0.051±0.011a 0.049±0.005a
AFD 2.78±0.85b 3.25±0.68b 3.72±0.72b 3.74±0.33b 3.21±0.37b 3.24±0.67b
SFC: s tarch fed cont rol, SFD: starch fed diab eti c, AEFC0.1: ele phant foot yam extract at 0.1% fed cont rol, AEFD0.1: ele phant foot yam extract at 0. 1% fed diabetic, AEFC0.25:
elepha nt foot yam extr act at 0.25% fe d control, AEFD0.25: elep hant foot yam extract at 0.25% fed diabetic, AFC: amino guanidine fed cont rol, AFD: aminoguani dine fed
diabetic. Values are expressed as mean ± Standard Devi ation (SD) of control and di abetic groups. Value of ‘n’ is 6 for control groups and 8 fo r diabetic groups. Values with
different alphabets in the same col umn indic ate signific ant differe nces among gr oups at P < 0.05
0
50
100
150
200
250
300
350
400
450
Experime ntal Groups
Fasting Blood Sugar(mg/dl
)
SFC
SFD
AEFC0.1
AEFD0.1
AEFC0.25
AEFD0.25
AFC
AFD
a
e
a
d
a
c
a
b
Fig. 1 Effect of acetone extract of elephant foot yam on fasting blood sugar (mg/dl) in control and diabetic rats. SFC: starch fed control, SFD: starch
fed diabetic, AEFC0.1: elephant fo ot yam extra ct at 0.1% fed control, AEFD0.1: ele phant foot yam extract a t 0.1% fed diabetic, AEFC0.25: elepha nt foot yam
extract at 0.25% fed control, AEFD0.25: elephant foot yam extract at 0.25 % fed diab etic, AF C: aminoguanidi ne fed co ntrol, AFD: aminoguanidine fed
diabetic. Values are expressed as mean ± Standard Deviation (SD) of control and diabetic groups (n values as in Ta ble 1 ) at P < 0.05.

Anti-diabetic effect of elephant-foot yam. Harshavardhan et al.
phenols and flavonoids. Presence of such bioactive compo-
nents in elephant-foot yam was reported by earlier workers
(Khan et al. 2008b; Nataraj et al. 2009). Research work has
shown that phenols and flavonoids have antidiabetic proper-
ties (Thompson et al. 1984; Pathak et al. 1991; Ahmad et al.
2000; Waltner-Law et al. 2002; Young et al. 2008). These
bioactive components of plants scavenge free radicals, in-
hibit lipid peroxidation and prevent secondary complica-
tions of diabetes (Sabu and Ramadasan 2004; Kwon et al.
2007; Truong et al. 2009; Jamuna et al. 2011).
Polyphenols control diabetes by inhibiting α-amylase
and α-glucosidase enzymes in volved in hyperglycemia
(Loizzo et al. 2011). Flavonoids have the ability to regene-
rate beta cells of pancreas and stimulate insulin secretion
(Chakravarti et al. 1980, 1981; Hoa et al. 2007). Quercetin
(bioflavonoid) present in apple and onion improved diabetic
condition with respect to diet intake, water intake, gain in
body weight, urine output, urine sugar, fasting blood sugar
and glomerular filtration rate (Shetty et al. 2004). Benefi-
cial effect of polyphenols and flavonoids present in banana
flower and pseudostem on diabetic parameters like urine
volume, urine sugar and fasting blood sugar has been re-
ported (Jamuna et al. 2011).
CONCLUSION
From this study it can be concluded that elephant-foot yam
may be used as therapeutic dietary source to minimize com-
plications of diabetes. Further investigations are underway
to understand the mechanism of antidiabetic potential of
elephant-foot yam.
ACKNOWLEDGEMENTS
The authors thank Dr. V. Prakash, Director, CFTRI for constant
encouragement. Mr. Harshavardhan Reddy thanks the Council of
Scientific and Industrial Research (CSIR), New Delhi, India, for
awarding a Research Fellowship. Technical assistance provided by
S. Vishwanatha is gratefully acknowledged. The authors thank Dr.
Jaime A. Teixeira da Silva for significant improvements to lan-
guage.
REFERENCES
Adyanthaya, Kwon YI, Apostolidis E, Shetty K (2010) Health benefits of
apple phenolics from post harvest stages for potential type 2 diabetes
manage ment using in vitro models. Journal of Food Biochemistry 34, 31-49
Ahmad M, Akhtar MS, Malik T, Gilani AH (2000) Hypoglycemic action of
flavonoi ds fraction of Cuminum nigrum seeds. Phytotherapy Research 14,
103-106
Angayarkanni J, Ramkumar KM, Poornima T, Priyadarshini U (2007)
Cytotoxic activity of Amorphophallus paeoniifolius tuber extracts in vitro.
American-Eurasian Journal of Agricultural Environmental Sciences 2 (4),
395-398
Angayarkanni J, Ramkumar KM, Priyadharshini U, Ravendran P (2010)
Antioxi dant potential of Amorphophallus paeoniifolius in relation to their
phenolic content . Pharmaceutical Biology 48 (6), 659-65
Baynes JW (1991) Role of oxidative stress in development of complications in
diabetes. Diabetes 40, 405-412
Bieri JG, Stoewsand GS, Briggs GM, Phillips RW, Woodard JC, Knapka JJ
(1997) Report of the American Institute of Nutrition Adhoc Committee on
standards for nutritional studies. Journal of Nutrition 107, 1340-348
Bonnefont-Rousselot D, Bastard JP, Jaudon MC, Delattre J (2000) Conse-
quence s of the diabetic statu s on the oxidant/antio xidant balance. Diabetes
Metabolism 26, 163-176
Bowers LD (1980) Kinetic serum creatinine assays I. The role of various fac-
tors in determining specificity. Clinical Chemistry 26, 551-554
Boyer J, Liu RH (2004) Apple phytochemicals and their health benefits.
Nutrition Journal 3, 5
Chakravarti BK, Gupta S, Gambir SS, Gode KD (1980) Pancreatic beta cell
regeneration. A novel antidiabetic mechanism of Pterocarpus marsupium
Roxb. Indian Journal of Pharmacology 12, 123-127
Chakravarti BK, Gupta S, Gambir SS, Gode KD (1981) Pancreatic beta cell
regeneration in rats by (−) epicatechin. The Lancet 2, 759-760
Chandra A, Singh R K, Tewari L (2004) Antioxidative potential of herbal
hypoglycemic agents in diabetes – an overview. SFRR-Indian Bulletin 3, 24-
26
Chatterjee A, Pakrashi SC (2001) The Treatise on Indian Medicinal Plants
(Reprinted Edition), Publications and Information Directorate, New Delhi, 6,
pp 29-30
Chen V, Ianuzzo CD (1982) Dosage effect of streptozotocin on rat tissue en-
zyme activities and glycogen concentration. Canadian Journal of Physiology
and Pharmacology 60, 1251-1256
Chopra RN, Chopra IC, Handa KL, Kapur LD (1958) Indigenous Drugs of
India (2nd Edn), P ublished b y U. N. Dhur a nd Sons P vt. Ltd. , Calcut ta, pp
494-543
Chung IM, Kim EH, Yeo MA, Kim SJ, Seo MC, Moon HI (2011) Antidia-
betic effects of three Korean sorghum phenolic extracts in normal and strep-
tozotocin-induced diabetic rats. Food Research International 44, 127-132
Day C (1998) Traditional plant treatment for diabetes mellitus: Pharmaceutical
foods. Britain Journal of Nutrition 80, 5-6
Day C, Cartwright T, Provost J, Bailey CJ (1990) Hypoglycaemic effect of
Momordica charantia extracts. Planta Medica 56, 426-429
Dey YN, Das SS, Sen M, De S, Ghosh AK (2009) Effects of petroleum ether
extract of Amorphophallus paeoniifolius tuber on central nervous system in
mice. Indian Journal of Pharmaceutical Sciences 71 (6), 651-655
Dey YN, De S, Ghosh AK (2010) Anti-inflammatory activity of methanolic ex-
tracts of Amorphophallus paeoniifolius and its possible mechanism. Inter-
national Journal of Pharma and Biosciences 1 (3), 1-8
Frode TS, Medeiros YS (2008) Animal models to test drugs with potential
antidiabetic activity. Journal of Ethnopharmacology 115, 173-183
Ghani A (1998) Medicinal Plants of Bangladesh, Asiatic Soci ety of Bangladesh.
Dhaka, Bangladesh, pp 77-78
Halliwell B, Gutteridge JMC (1985) In: Free radicals in Biology and Medi-
cine, Oxford Clarendon Press, London, pp 24-86
Harborne JB (1984) A guide to modern techniques of plant analysis. In: Phyto-
chemical Methods (2nd Edn), Chapman and Hall, London, 288 pp
Harter LN (1960) Critical values for Duncan’s new multiple range test. Bio-
metrics 16, 671-685
0
1
2
3
4
5
6
7
8
Experimental Groups
Glomerular Filtration Rat
e
(ml/min)
SFC
SFD
AEFC0.1
AEFD0.1
AEFC0.25
AEFD0.25
AFC
AFD
a
e
a
d
a
c
a
b
Fig. 2 Effect of acetone extract of elephant foot yam on glomerular filtration rate (ml/min) in control and diabetic rats. SFC: starch fed control, SFD:
starch fed diabetic, AEFC0.1: elephant foot yam extract at 0.1% fed control, AEFD0.1: elephant foot yam extract at 0.1% fed diabetic, AEFC0.25: elepha nt
foot yam extract at 0.25% fed control, AEFD0.25: elephant foot yam extract at 0.25 % fed diabetic, AFC: aminoguanidine fed control, AFD: amin o-
guanidine fed diabetic. Values are expressed as mean ± Standard Deviation (SD) of contro l and diabetic groups (n values a s in Tab le 1) at P < 0.05.

International Journal of Biomedical and Pharmaceutical Sciences 7 (1), x-y ©2013 Global Science Books
Harunobu A, Buxiang S, Carmia B (2009) Lycium barbarum (goji) juice im-
proves in vivo antioxi dant biomark ers in se rum of healthy adult s. Nutrition
Research 29, 19-25
Henriksen EJ (2000) Oxidative stress and antioxidant treatment: Effect on
muscle glucose transport in a nimal model s of type1and type2 diabetes. In:
Packer L, et al. (Eds) Antioxid ant in Diabe tes Management, Marcell Dekker
Inc., NewYork, pp 303-317 please define all editors
Hoa NK, Norberg A, Sillard R, Van Phan D, Thuan ND, Dzung DT (2007)
The possible mechanisms by which phanoside stimulates insulin secretion
from rat islets. Journal of Endocrinology 192, 389-394
Hugget ASG, Nixon DA (1957) Use of glucose oxidase, peroxidase and O-
dianisidine in the determination of blood glucose and urinary glucose. Lancet
273, 368-370
Jamuna JB, Mahadevamma S, Vishwanatha S, Salimath PV (2010) Effect
of banana (Musa sp. cultivar Elakki Bale) flower and stem on enzyme activi-
ties of intestinal and renal disaccharidases in streptozotocin-induced diabetic
rats. Journal of Food Biochemistry 34 (3), 564-580
Jamuna JB, Puneeth Kumar A, Paramahans VS (2 011) Effect of banana
(Musa sp. var. Elakki Bale) flower and pseudostem on antioxidant and
lysosomalenzyme activities in streptozotocin-induced diabetic rats. Journal
of Pharmacy Research 4 (4), 1087-1091
Khan A, Rahman M, Islam MS (2008a) Antibacterial, antifungal and cyto-
toxic activities of amblyone isolated from Amorphophallus campanulatus
Blume ex. Decne. Indian Journal of Pharmacology 40 (1), 41-44
Khan A, Rahman M, Islam MS (2008b) Antibacterial, antifungal and cyto-
toxic activities of 3, 5-diacetyltambulin isolated from Amorphophallus cam-
panulatus Blume ex. Decne. DARU 16 (4), 239-244
Khan A, Rahman M, Islam S (2007) Antibacterial, antifungal and cytoto xic
activities of tuberous roots of Amorphophallus campanulatus. Turkish Jour-
nal of Biology 31, 167-172
Khan A, Safdar M (2003) Role of nutrients, spices and natural products in dia-
betes mellitus. Pakistan journal of nutrition 2, 1-12
Kirtikar KR, Basu BD (1994) Indian Medicinal Plants (Vol 4, 2nd Edn), Dehra
Dun Publisher Ltd., India, pp 2609-2610
Kumar P, Clark M (2002) Diabetes mellitus and other disorders of metabolism.
In: Clinical Medicine (Vol 2), WB Sunders, London, pp 1069-1071
Kumar R, Arora V, Ram V, Bhandari A, Vyas P (2011) Hypoglycemic and
hypolipi demic effect of allopolyherbal for mulation s in strept ozotocin induced
diabetes mellitus in rats. International Journal of Diabetes Mellitus
doi:10.1016/j.ijdm.2011.01.005
Kwon YI, Apostolidis E, Shetty K (2007) Evaluation of pepper (Capsicum
annuum) for manage ment of d iabetes and hypertension. Journal of Food Bio-
chemistry 31, 370-385
Loizzo MR, Di LG, Boselli E, Menichini F, Frega NG (2011) Inhibitory acti-
vity of phenolic compounds from extra virgin olive oils on the enzymes in-
volved in diabetes, obesity and hypertension. Journal of Food Biochemistry
35 (2), 381-399
Maithili V, Dhanabal SP, Mahendran S, Vadivelan R (2011) Antidiabetic
activity of ethanolic extract of tubers of Dioscorea alata in alloxan induced
diabetic rats. Indian Journal of Pharmacology 43 (4), 455-459
Mallick C, Maiti R, Ghosh D (2006) Anti-diabetogenic effects of separate and
composite extract of seed of jamun (Eugenia jambolana) and root of kadali
(Musa paradisiaca) in streptozotocin induce d diabetic male al bino rats: A
comparative study. International Journal of Pharmacology 2, 492-503
Mao CP, Gu ZL (1999) Effect of Amorphophallus konjac fine powder to lower
blood gl ucose. Chinese Journal of Modern Applied Pharmacy 16, 17-19
Michael B (2001) Bioche mistry and molecular cell biol ogy of diabetic compli-
cations. Nature 414, 813-820
Miller GL (1959) Use of dinitrosalicylic acid reagent for determination of
reduci ng sugar. Analytical Chemistry 31, 426-428
Misra RS, Nedunchezhiyan M, Swamy TMS, Edison S (2002) Mass multi-
plication technique for producing quality planting material of Amorpho-
phallus paeoniifolius. Tropical Science 34, 371-376
Nataraj HN, Murthy RLN, Ramachandra SS (2009) In vitro quantificat ion
of flavo noids and phenolic content of – Sura n. International Journal of Chem
Tech Research 1 (4), 1063-1067
Naveen S, Khanum F (2010) Antidiabetic, antiatherosclerotic and hepatopro-
tective properties of Decalepis hamiltonii in streptoz otocin-i nduced d iabetic
rats. Journal of Food Biochemistry 34 (6), 1231-1248
Oyedemi SO, Yakubu MT, Afolayan AJ (2011) Antidiabetic activities of aque-
ous leaves extract of Leonotis leonurus in streptozotocin induced diabetic rats.
Journal of Medicinal Plants Research 5 (1), 119-125
Pari L, Umamaheswari J (2000) Antihyperglycaemic activity of Musa sapien-
tum flowers: Effect on lipid peroxidation in alloxan diabetic rats. Phytothe-
rapy Research 14, 1-3
Pathak D, Pathak K, Singla AK (1991) Flavonoids as medicinal agents –
recent advances. Fitoterapia 62, 371-389
Platel K, Srinivasan K (1997) Plant foods in the management of diabetes mel-
litus: Vegetables as potential hypoglycemic agents. Die Nahrung 41 (2), 68-
74
Prakash RI, Sarika JL, Prashant RV, Sumit KA, Rajesh AS, Arun TP
(2011) Antidiabetic potential of unripe Carissa carandas Linn. fruit ex-
tract. Journal of Ethnopharmacology 135 (2), 430-433
Prathibha S, Bana-Nambisan, Leelamma S, Nambisan B (1995) Enzyme in-
hibitors in tuber crops and their thermal stability. Plant Foods for Human
Nutrition 48, 247-257
Rahimi R, Nikfar S, Larijani B, Abdollahi M (2005) A review on the role of
antioxidants in the management of diabetes and its complications. Biomedi-
cine and Pharmacotherapy 59, 365-373
Ramalingam R, Himabindu K, Bindumadhavi B, Ravindernath A, David B
(2010) Phytochemical and anthelmintic evaluation of corm of Amorphophal-
lus campanulatus. International Journal of Pharma and Bio Sciences 1 (2),
1-9
Rao BK, Kesavulu MM, Giri RAC (1999) Antidiabetic and hypolipidemic
effects of Momordica cymbalaua Hook fruit powder in alloxan diabetic rats.
Journal of Ethnopharmacology 67, 103-109
Rohrbach DH, Martin GR (1982) Structure of basement membrane in normal
and diabetic tissues. Annals of the New York Academy of Sciences 401, 203-
211
Sabu MC, Ramadasan K (2004) Antidiabetic activity of Aegle marmelos and
its relationship with its antioxidant properties. Indian Journal of Physiology
and Pharmacology 48 (1), 81-88
Sakthi PS, Vadivu R, Jayshree N (2010) In vitro and in vivo antidiabetic acti-
vity of the leaves of Ravenala madagascariensis Sonn., on allo xan induc ed
diabetic rats. Journal of Pharmaceutical Science and Technology 2 (9), 312-
317
Shastry RA, Biradar SM, Mahadevan KM, Habbu PV (2010) Isolation and
characterization of secondary metabolite from Amorphophallus paeoniifolius
for hepatoprotective activity Research Journal of Pharmaceutical, Biological
and Chemical Sciences 1 (4), 429-437
Shetty AK, Rashmi R, Rajan MGR, Sambaiah K, Salimath PV (2004) Anti-
diabetic influenc e of querc etin in stre ptozotocin-ind uced diabetic rats. Nutri-
tion Research 24, 373-381
Shilpi JA, Ray PK, Sarder MM, Uddin SJ (2005) Analgesic activity of Amor-
phophallus campanulatus tuber. Fitoterapia 76, 367-369
Shetty AK, Kumar GS, Sambaiah K, Salimath PV (2005a) Effect of bitter
gourd (Momordica charantia) on glycaemic status in streptozotocin-ind uced
diabetic rats. Plant Foods for Human Nutrition 60, 109-112
Shimomuna H, Spiro RG (1987) Studies on macro molecular components of
human gl omerular baseme nt membra ne and alterati ons in diabe tes. Diabetes
36, 374-381
Srinivas T, Ramanathan S (2005) A study on economic analysis of elephant
foot ya m production in India. Agricultural Economics Research Review 18,
241-252
Surendhra KS, Rajasekar N, Armstrong VRN, Paramaguru R (2011)
Hepatoprotective and antioxidant effects of Amorphophallus campanulatus
against acetaminophen-induced hepatotoxicity in rats. International Journal
of Pharmacy and Pharmaceutical Sciences 3 (2), 202-205
Thompson LU, Yoon JH, Jenkins DJ, Wolever TM, Jenkins AL (1984) Rela-
tionshi p betwee n polyphe nol intake and blood glucose response of normal
and diabetic individuals. American Journal Clinical Nutrition 39, 745-751
Tripathi AS, Chitra V, Sheikh NW, Mohale DS Dewani AP (2010) Immuno-
modulatory activity of the methanol extract of Amorphophallus campanu-
latus (Araceae) tuber. Tropical Journal of Pharmaceutical Research 9 (5),
451-454
Truong TM, Nagashima F, Nguyen VC (2009) Antioxidant activities and
hypolipidemic effects of an aqueous extract from flower buds of Cleistocalyx
operculatus (Roxb.) Merr. and Perry. Journal of Food Biochemistry 33 (6),
790-807
Wadkar KA, Magdum CS, Patil SS, Naikwade NS (2008) Anti-diabetic pot-
ential and Indian medicinal plants. Journal of Herbal Medicine and Toxicol-
ogy 2 (1), 45-50
Waltner-Law ME, Wang XL, Law BK, Hall RK, Nawano M, Granner DK
(2002) Epigallocatechingallate, a constituent of green tea, represses hepatic
glucose pr oductio n. Journal of Biological Chemistry 277, 34933-34940
Wild S, Roglic G, Green A, Sicree R, King H (2004) Global prevalence of dia-
betes estimates for the year 2000 and projections for 2030. Diabetes Care 27,
1047-1053
Yadu ND, Ajoy KG (2010) Pharmacognostic evaluation and phytochemical
analysis of the tuber of Amorphophallus paeoniifolius. International Journal
of Pharma Research and Development 2 (9), 44-49
Yokozawa T, Chung HY, He LQ, Qura H (1996) Effectiveness of green tea
tannin on rats with chronic renal failure. Bioscience, Biotechnology and Bio-
chemistry 60, 1000-1005
Young IK, Emmanouil A, Kalidas S (2008) Inhibitory potential of wine and
tea against α-amylase and α-glucosida se for mana gement of hyperglyc emia
linked to type 2 diabetes. Journal of Food Biochemistry 32, 15-31
Young IK, Emmanouil A, Kalidas S (2007) Eval uation of pepper (Capsicum
annuum) for manage ment of d iabetes and hypertension. Journal of Food Bio-
chemistry 31 (3), 370-385
Yusuf M, Chowdhury JU, Yahab MA, Begum J (1994) Medicinal Plants of
Bangladesh, BCSIR Laboratories, Bangladesh, 20 pp
Zhang XF, Tan BK (2000) Antihyperglycaemic and anti-oxidant properties of
Andrographis paniculata in normal and diabetic rats. Clinical and Experi-
mental Pharmacology and Physiology 27, 358-363