Antidiabetic effect of cashew (Anacardium occidentale L.) stem-bark in alloxan-induced diabetic rats

Abstract

Objective: The present study was undertaken to investigate the anti-diabetic activity of methanol extract of stem-bark of cashew [Anacardium occidentale Linn. (Anacardiaceae)l in alloxan-induced diabetic rats. Methods: The extract (200 mg kg-1 body weight, p.o) was administered daily for 28 days, 48 hrs after alloxan injection (100 mg kg 1 body weight, i.v.). At the end of the experimental period, all animals were fasted for 12 hrs. Blood glucose, plasma lipids, ascorbic acid, electrolytes and thiobarbituric acid reactive substances (TBARS; marker of lipid peroxidation) were determined. Results: The alloxan-diabetic rats treated with the extract showed significant reductions (p<0.05) in fasting blood glucose, total cholesterol, triglyceride, LDL-cholesterol, TBARS and potassium concentrations and significant increases (p<0.05) in plasma concentrations of HDL-cholesterol, HDL-cholesterol/total cholesterol ratio, HDL-cholesterol/ LDL-cholesterol ratio and ascorbic acid when compared with the untreated alloxan-diabetic rats. Plasma concentrations of sodium, magnesium and calcium were comparable (p>0.05) in all the experimental groups. Conclusion: The results of the present study indicate that oral administration of methanol extract of cashew stem-bark might reduce diabetic-related cardiovascular complications through improved lipid profile and reduced oxidative stress. The study also supports the public belief among the Yoruba in the south-west of Nigeria, that cashew extract could be a useful agent in the prevention and management of diabetes