International Journal of Animal and Veterinary Advances 4(4): 303-305, 2012
ISSN: 2041-2894
© Maxwell Scientific Organization, 2012
Submitted: June 20, 2012
Accepted: July 28, 2012
Published: August 20, 2012
Anti-Diabetic Activity of Cynanchum acutum Extract in Alloxan-Induced Diabetic Rats
1
Jasem Estakhr, 2Fereshteh Javadian, 1Zohre Ganjali, 1Mehdi Dehghani and 1Abbas Heidari
1
Department of Biology, Faculty of Science, University of Zabol, Zabol, Iran
2
Department of Biology, Faculty of Science, Mashhad Branch, Islamic Azad University,
Mashhad, Iran
Abstract: The present study investigates the anti-diabetic potential of Cynanchum acutum extract in alloxaninduced diabetic rats. The effects of an ethanolic extract of Cynanchum acutum on serum glucose, total cholesterol,
triglycerides, plasma insulin and liver glycogen were examined in control and experimental groups. Cynanchum
acutum extract reduced the serum glucose concentration at 24, 48 and 72 h. To verify the activity sub-chronically,
the extract administered orally in the doses of 25, 50 and 100 mg/kg to diabetic rats for 30 days, that significantly
reduced the level of glucose, total cholesterol and triglycerides with an increase in insulin and glycogen
concentration to near normal levels in a dose-dependent manner. The results indicate that Cynanchum acutum
extract possess anti-diabetic potential in alloxan-induced diabetic rats.
Keywords: Anti-diabetic activity, alloxan-induced diabetic rat, Cynanchum acutum hyperglycemic and antioxidant activity of metanolic
extract of aerial parts of Cynanchum acutum has been
reported and antiulcerogenic effects of ethanolic extract
of the plant also have been shown in rats (Atta et al.,
2005). This study was undertaken to evaluate the
antidiabetic activity of ethanolic extract of Cynanchum
acutum, since up to now no pharmacological evaluation
has been done on Cynanchum acutum for its
antidiabetic activity. This prompted us to pursue the
activity and was examined for their efficacy and for
determination of their possible mechanism of action.
INTRODUCTION
Cynanchum acutum, belongs to the family
Apocynaceae. This family (including Asclepiadaceae)
is a monophyletic family (Judd et al., 2002) containing
355 genera and 3700 species, the majority of them are
poisonous and many have medicinal uses. The plant is
quiet poisonous with few medical applications. It has
been used as a purgative in the French pharmaceutical
Codex (Garnier et al., 1961) and its milky latex is used
for skin and eye problems in Tunisian folk medicine
(Sayed et al., 2003; Boukef, 1986) and its seeds are
edible in some parts of Iran. The photochemical
investigations on Cynanchum acutum. have revealed
the presence of several natural compounds including βsitosterol, lupeol, lupyl acetate study α-amyrin (Halim
et al., 1990), sarcostine, quercetin and quercetin 3-O-βD-galactoside (El-Sayed et al., 1994), four flavonoid
glycosides: quercetin di-O-hexoside, quercetin 3-Orhamnosyl(1→2)glycoside,
quercetin
3-Ogalactosidestudy quercetin 3-O-xyloside (Heneidak et
al., 2006) and 2 simple coumarins: scopoletin and
scoparone (El-Demerdash et al., 2009) as well as of
seven other flavonoids (Ghada et al., 2008). Studies on
other species of this genus which have close affiliations
with C. acutum also have been done and the following
products have been distinguished: steroidal glycosides
(Liu et al., 2007), carbohydrates (Yi-Bin et al., 2004),
alkaloids (Tian-Ying et al., 2001), phenolic compounds
(Lou et al., 1993) study triterpenes (Konda et al., 1990).
This close affiliation enables us to predict the presence
of these products in C. acutum, since close genotypes
ends to production of similar compounds. Anti-
MATERIALS AND METHODS
Alloxan monohydrate was purchased from Sigma
Chemical Company, St Louis, MO, USA. Gliclazide
was procured from Dr. Ahmadi Lab, Zabol, Iran. All
the other chemicals used were of analytical grade and
were purchased from commercial sources. Cynanchum
acutum was collected during the month of April – June
2011 from Sistan and Baluchestan province, Iran.
About 1 kg of Cynanchum acutum was chopped into
small pieces, shade dried, coarsely powdered and
exhaustively extracted with ethanol by cold percolation
method. After 72 h, the solvent was decanted and
distilled-off over boiling water bath. Further
concentrations were done under reduced pressure using
rotary flash evaporator and finally dried in a desecrator.
Adult male albino rats of Wistar strain weighing 150 200 g used for the study were obtained from Razi
Institute, Mashhad, Iran. Animals were housed in
polypropylene cages and maintained under standard
conditions (12 h light and dark cycles, at 25±3º C and
Corresponding Author: Jasem Estakhr, Department of Biology, Faculty of Science, University of Zabol, Zabol,Iran, Tel.
+989179283966
303
Int. J. Anim. Veter. Adv.,4(4): 303-305, 2012
Table 1: The Effect of Cynanchum acutum extract on the serum glucose (mg/dL) levels in hyperglycemic rats for 24, 48 and 72 h
Treatment (mg/kg)
24 h
48 h
72 h
Group I
121.00 ± 3.77
120.00 ± 4.12
121.00 ± 4.10
Group II
605.44 ± 8.23a***
617.54 ± 7.44a***
629.85 ± 7.78a***
Group III
556.25 ±7.13b***
443.16 ± 8.81b***
314.33 ± 8.16b***
***
Group IV
535.72 ± 9.19bNS
372.98 ± 8.32b
240.22 ± 9.82b***
Group V
421.73 ± 9.53b***
248.73 ± 9.27b***
168.97 ± 8.61b***
Group VI
282.27 ± 8.24b***
153.26 ± 8.17b***
116.61 ± 8.64b***
Values represent mean ± S.D. (n = 6). *p<0.05, **p<0.01, ***p<0.001 when compared to control animals; NS: Non-significant
Table 2: The anti diabetic effect of Cynanchum acutum extract treated in alloxan-induced rats for 30 days
Serum glucose
Liver glycogen (mg/gm
Total cholesterol
Triglycerides
Treatment (mg/kg) (mg/dL)
Plasma insulin (µU/L)
tissue)
(mg/dL)
(mg/dL)
Group I
120.00±5.35
13.13±1.41
6.54±3.15
62.21±2.84
65.35±3.59
Group II
487.13±10.32a***
8.76±1.91a***
14.20±2.23a***
111.18±2.73a***
114.87±3.47b***
Group III
111.14±6.36b***
11.84± 1.68b***
25.13±2.41b***
63.31±2.37b***
74.76±3.10b***
Group IV
114.18±7.14b***
12.05±1.17b***
45.91±2.11b***
72.71±2.89b***
76.81±3.41b***
Group V
99.35±5.12b***
11.23±1.44b***
52.16±2.45b***
60.83±2.01b***
62.19±2.97b***
Group VI
87.97±7.10b***
13.14±1.93b***
58.47±2.06b***
53.98±3.19b***
54.94±3.34b***
Values represent mean ± S.D. (n = 6). *p< 0.05, **p<0.01, ***p<0.001 when compared to control animals; NS: Non-significant
35-60% humidity). present study, thirty six rats were
used. Group I: contained six animals that served as
control. The remaining 30 animals were given alloxan
intra-peritoneally (120 mg/kg body weight) to induce
hyperglycemia. After 72 h, the hyperglycemic
conditions in these animals were ensured from their
blood glucose values which were above 250 mg/dL.
Further they were segregated into 5 groups containing
six animals each and were treated as follows:
Standard pelletized feed and tap water were provided ad
libitum. In the
Group II: Disease-control (alloxan 120 mg/kg i.p.)
Group III: Diabetic + Glidazide (25 mg/kg of Body
wt)
Group IV: Diabetic + Cynanchum acutum (25 mg/kg
of Body wt)
Group V: Diabetic + Cynanchum acutum extract (50
mg/kg of Body wt)
Group VI: Diabetic + Cynanchum acutum (100 mg/kg
of Body wt)
Serum glucose concentration was measured at 24,
48 and 72 h from the blood samples. The doses was
continued for 30 days and on day 31, the animals were
sacrificed by cervical decapitation under mild
anesthesia and the blood were collected in tubes with
clot activators and heparin to get serum and plasma
while the liver was removed immediately, washed with
ice-cold saline and stored in deep freezer at -20ºC for
glycogen estimation. Plasma insulin was estimated by
ELISA method using Biotech-ELX-50, (U.S.), liver
glycogen using UV visible spectrophotometer, Serum
glucose, total cholesterol and triglycerides were
estimated using Randox-daytona fully automated
random axis analyzer (U.K.). Statistical evaluation of
analytical data was done by Student's t-test using SPSS
package. The values are expressed as the
mean±standard Deviation (S.D) and values with
p<0.01, p<0.001, p<0.05 were considered significant.
RESULTS
Table 1 shows the effect of Cynanchum acutum
extract on serum glucose level in hyperglycemic
animals. The level of glucose in animals treated with
gliclazide and Cynanchum acutum extract (25 mg/kg)
for 24, 48 and 72 h showed a decrease in the level of
glucose. In 50 and 100 mg/kg dose, the level of glucose
further decreased with 24, 48 and 72 h, the decrease
was drastic in 72 h. On observing the response with 100
mg/kg dose for 72 h the level of glucose was found near
to the control value, thereby indicating the anti diabetic
potential of Cynanchum acutum. Table 2 illustrates the
effect of Cynanchum acutum extract for a sub-chronic
period of 30 days. The diabetic control rats (Group II)
showed a significant increase in glucose, total
cholesterol and Triglycerides levels, while plasma
insulin and liver glycogen were reduced drastically
when compared to the control animals. On treatment
with standard drug gliclazide, all the parameters found
to attain near normal values. The animals treated with
Cynanchum acutum extract in different doses (25, 50
and 100 mg/kg) showed dose-dependent decrease in
levels of glucose, total cholesterol and triglycerides
while increase in plasma insulin and liver glycogen
were obtained when compared to the disease-control
group.
DISCUSSION
The results of anti-diabetic study clearly showed
that Cynanchum acutum extract produced a significant
hypoglycemic action. At 25 mg/kg dose, the activity of
Cynanchum acutum extract in lowering the serum
glucose and promoting glycogen storage was found to
304 Int. J. Anim. Veter. Adv.,4(4): 303-305, 2012
be higher than the standard drug. The possible
mechanism for this action might be due to the inhibition
of the enzyme glycogen phosphorylase, an enzyme that
catalyzes the process of glycogenolysis thereby
inhibiting glucagon which on feedback inhibition
favours the production of insulin as reported by Liu
et al. (2007). This might be the cause for drastic
depletion of glucose and lipid parameters such as total
cholesterol and triglyceride in hyperglycemic condition.
Further studies are necessary to determine the exact
nature of the active principles and mechanism of action
of Cynanchum acutum extract. From this study we can
conclude that Cynanchum acutum extract has beneficial
effects on blood glucose and lipid abnormalities. It has
the potential to impart therapeutic effect in diabetes.
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