Purpose: To investigate the effect of
Astragalus membranaceus
(Fisch.) Bunge. extract (AMBE) on
streptozotocin-induced diabetic rats.
Methods: The aqueous extract of AMB was obtained by steeping the dried
Astragalus membranaceus
(Fisch.) Bunge. in water at 60
oC three times, each for 1 h, before first drying in an oven at 100
oC and
then freeze-drying the last extract thus obtained. Diabete model rats was induced by a single
intraperitoneal injection of a freshly prepared solution of streptozotocin (50 mg/kg). The rats were
randomly divided into 6 groups of ten rats each: negative control group, normal control group, reference
group (glibenclamide1 mg/kgbody weight) as well as AMB extract groups, namely, 40, 80 and 160
mg/kg body weight. Antihyperglycemic effect was measured by blood glucose and plasma insulin levels.
Oxidative stress was evaluated in liver and kidney by antioxidant markers, viz, lipidperoxidation (LPO),
superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx) and catalase
(CAT), while blood serum levels of creatinine and urea were also determined in both diabetic control
and treated rats.
Results: Compared with diabetic rats, oral administration of AMBE at a concentration of 160 mg/kg
daily for 30 days showed a significant decrease in fasting blood glucose (109.438 ± 3.52, p < 0.05) and
increased insulin level (13.96 ± 0.74, p < 0.05). Furthermore, it significantly reduced biochemical
parameters (serum creatinine, 0.86 ± 0.29, p < 0.05) and serum urea (45.14 ± 1.79, p < 0.05). The
treatment also resulted in significant increase in GSH (49.21 ± 2.59, p < 0.05), GPx (11.96 ± 1.16, p <
0.05), SOD (14.13 ± 0.49, p < 0.05), CAT (83.25 ± 3.14, p < 0.05) level in the liver and kidney of
diabetic rats.
Conclusion: The results suggest that AMBE may effectively normalize impaired antioxidant status in
streptozotocin-induced diabetes in a dose-dependent manner. AMBE has a protective effect against
lipid peroxidation by scavenging free radicals and is thus capable of reducing the risk of diabetic
complications.
