Hypoglycemic activity of Erythrina variegata leaf in streptozotocin-induced diabetic rats

Erythrina variegata Linn. (Fabaceae), commonly known as Tiger's Claw, is a thorny deciduous tree grown in tropical and subtropical regions of Eastern Africa, Southern Asia, and Northern Australia. In India, its leaves are traditionally used for diabetes mellitus.

To evaluate the hypoglycemic activity of methanol extract of E. variegata leaf (MEEV) in streptozotocin (STZ)-induced diabetic Wistar rats.

Hyperglycemia was induced in rats by single intraperitoneal injection of STZ (55 mg/kg body weight). Three days after STZ induction, the hyperglycemic rats were treated with MEEV orally at the doses of 300, 600, and 900 mg/kg body weight daily for 21 days. Glibenclamide (1 mg/kg, orally) was used as reference drug. The fasting blood glucose levels were measured on every 7th day during the 21 days of treatment. Serum biochemical parameters including lipid content were estimated.

MEEV at the doses of 300, 600, and 900 mg/kg orally significantly (P < 0.01) and dose-dependently reduced and normalized blood glucose levels as compared to that of STZ control group; the dose 900 mg/kg being the most potent showing complete normalization of blood glucose levels. Serum biochemical parameters including lipid profile were significantly (P < 0.01) restored toward normal levels in META-treated rats as compared to STZ control animals.

This study concludes that E. variegata leaf demonstrated promising hypoglycemic action in STZ-induced diabetic rats substantiating its ethnomedicinal use.