In vivo antidiabetic and antioxidant activities of Coccinia grandis leaf extract against streptozotocin induced diabetes in experimental rats

To evaluate antidiabetic and antioxidative properties of Coccinia grandis leaf extract in experimental diabetic rats and to study the co-relation of the two in vivo. Ethanolic extract, showing the highest activity in in vitro experiments, was prepared in saline and given orally to streptozotocin induced albino Wistar diabetic rats for 21 days. Biochemical parameters, histopathological analyses, liver and muscles glycogen and in vivo antioxidant activity in normal, diabetic control, standard (metformin) and treated animals were determined and compared. Treatment of experimental rats with diabetes induced by streptozotocin by ethanolic leaf extract (500 mg/kg) caused significant (P < 0.001) reduction in blood glucose (312–169 mg/100 mL), increase in body weight (181–210 g) and serum insulin (1.28–3.10 IU/dL). It also maintained lipid profile and liver and kidney functions within normal range compared with diabetic control rats and almost at par with metformin-a standard antidiabetic drug. The oxidative stress induced decline in glutathione and catalase in liver and kidney tissues showed up to 60% recovery as a function of treatment. Histopathology of pancreas showed marked restorative effect in diabetic rats. The results suggest that Coccinia grandis ethanolic leaf extract has strong antidiabetic activity and can be meaningfully utilized in the management of diabetes.