Antidiabetic and antioxidant potentials of Vitellaria paradoxa barks in alloxan-induced diabetic rats

Background Vitellaria paradoxa (V. paradoxa) is a plant used in traditional medicine in the treatment of many diseases including diabetes mellitus. Although the different parts of this plant are used empirically as antidiabetic drug, no scientific work to our knowledge has yet been undertaken to evaluate its effects on blood glucose, and lipid and antioxidant parameters of diabetic animals. The objective of this study is therefore to evaluate the hypoglycaemic, hypolipidemic and antioxidant activities of the aqueous extract of V. paradoxa barks in diabetic rats. Methods Diabetes was induced by intraperitoneal injection of alloxan (120 mg/kg bw). Thirty male albino rats were divided into groups and orally treated for 14 days with distilled water, glibenclamide (2.5 mg/kg bw) and aqueous extract of V. paradoxa (125, 250 and 500 mg/kg bw). Glycaemia, insulin level, relative body weight, hepatic glycogen level, some liver enzymes, and lipid and antioxidant parameters were evaluated. Results The results showed that the extract caused a significant increase in relative body weight, insulin level, HDL-cholesterol, hepatic glycogen rate, and fructose-1,6-biphosphate and glucokinase activities. A significant decrease in glycaemia, glucose-6-phosphatase activity, total cholesterol, triglycerides and LDL-cholesterol were also observed after the administration of V. paradoxa. Glutathione level and the activities of catalase and superoxide dismutase increased significantly while the nitric oxide and malondialdehyde levels decreased significantly in the liver of animals treated with the extract of V. paradoxa. Conclusion These results justify the hypoglycaemic, hypolipidemic and antioxidant effects of aqueous extract of V. paradoxa barks, which can reduce the complications associated with diabetes.