Comparative antioxidant and hypoglycaemic effects of aqueous, ethanol and n-hexane extracts of leaf of <i>Vitex doniana</i> on streptozotocin-induced diabetes in albino rats

Abstract

Several herbal preparations are used to treat diabetes, but their reported hypoglycemic effects are complex. This study therefore was designed to evaluate the effect of aqueous extract of Vitex doniana leaves on oxidative stress and lipid peroxidation in streptozotocin-induced diabetic and non-diabetic rats. Diabetes was induced intraperitoneally using 50 mg/kg streptozotocin, while diabetic rats were treated in 12 h cycles for four weeks with 100 mg/kg of the extract and glibenclamide (2.5 mg/kg). Nondiabetic control rats received distilled water. The levels of fasting blood sugar (FBS), thiobarbituric acid reactive substance (TBARS), aspartatate aminotransfrease (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), catalase (CAT) and superoxide dismutase (SOD) activities total, conjugated and unconjugated bilirubin concentration were assayed. The results indicate that the concentrations of TBARS, ALT, AST, ALP and bilirubin were significantly increased while the activities of SOD and CAT were reduced in the diabetic animals (p<0.05). The extract significantly increased CAT and SOD activity and reduced FBS, TBARS, ALT, AST, ALP and bilirubin concentrations significantly (p<0.05) compared to normal. However, glibenclamide treatment showed slight modification in the changes observed compared to the extract. The study concluded that the extract reversed diabetes and diabetes-induced oxidative changes in the hepatocytes, thus suggesting its use for the management of diabetic complications.

Keywords: Vitex doniana, lipid peroxidation, streptozotocin-induced diabetic

African Journal of Biotechnology Vol. 12(40), pp. 5933-5940