Antihyperglycemic activity and antioxidant role of Terminalia arjuna leaf in streptozotocin-induced diabetic rats.

CONTEXT: Terminalia arjuna Roxb. (Combretaceae), commonly known as Arjuna, is a large tree grown throughout the Indian peninsula and used traditionally for several medicinal purposes. OBJECTIVE: To evaluate antihyperglycemic and antioxidant role of methanol extract of T. arjuna leaf (META) in Wistar rats. MATERIALS AND METHODS: Hyperglycemia was induced in rats by single intraperitoneal injection of streptozotocin (STZ, 65 mg/kg body weight). Three days after STZ induction, the hyperglycemic rats were treated with META orally at the dose of 100 and 200 mg/kg body weight daily for 15 days. Glibenclamide (0.5 mg/kg, orally) was used as reference drug. The fasting blood glucose levels were measured on every fifth day during the 15-day treatment. Serum biochemical parameters such as serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), alkaline phosphatase (ALP), cholesterol, and total protein were estimated. Antioxidant properties were assessed by estimating hepatic lipid peroxidation, reduced glutathione (GSH), and catalase (CAT). RESULTS AND DISCUSSION: META at the dose of 100 and 200 mg/kg orally significantly (P < 0.001) and dose-dependently reduced and normalized blood glucose levels as compared with that of STZ control group. Serum biochemical parameters were significantly (P < 0.001) restored toward normal levels in META-treated rats as compared with STZ control. META treatment also significantly (P < 0.001) decreased lipid peroxidation and recovered GSH level and CAT activity toward normal as compared with STZ control. CONCLUSION: The present study infers that T. arjuna leaf demonstrated remarkable antihyperglycemic activity in STZ-induced diabetic rats. The potential antihyperglycemic action is plausibly due to its underlying antioxidant role.