Hypoglycemic Effect of Calotropis gigantea Linn. Leaves and Flowers in Streptozotocin-Induced Diabetic Rats.

OBJECTIVES To evaluate the hypoglycemic and anti-diabetic activity of chloroform extract of Calotropis gigantea leaves and flowers in normal rats and streptozotocin induced diabetes. METHODS The hypoglycemic activity in normal rats was carried out by treatment using chloroform extract of Calotropis gigantea leaf and flower 10, 20 and 50 mg/kg, orally. The oral glucose tolerance test was carried out by administering glucose (2 g/kg, p.o), to non-diabetic rats treated with leaf and flowers extracts at oral doses 10, 20 and 50 mg/kg, p.o and glibenclamide 10 mg/kg. The serum glucose was then measured at 0, 1.5, 3 and 5 hr after administration of extracts/drug. Streptozotocin-induced diabetic rats were administered the same doses of leaf and flower extracts, and standard drugs glibenclamide was given to the normal rats or 0.5 ml of 5% Tween-80, for 27 days. The blood sample from all groups collected by retro-orbital puncture on 7, 14, 21 and 27th days after administration of the extracts/drug and used for the estimation of serum glucose levels using the glucose kit. RESULTS The Calotropis gigantea leaves and flowers extracts were effective in lowering serum glucose levels in normal rats. Improvement in oral glucose tolerance was also registered by treatment with Calotropis gigantean. The administration of leaf and flower extracts to streptozotocin-induced diabetic rats showed a significant reduction in serum glucose levels. CONCLUSION It is concluded that chloroform extracts of Calotropis gigantea leaves and flowers have significant anti-diabetic activity.