Anti-diabetic activity of Tinospora cordifolia (Willd.) in streptozotocin diabetic rats; does it act like sulfonylureas?

Abstract

As an alternative medicine to treat diabetes mellitus, many herbal drugs are being studied throughout the world. In the present study, an attempt was made to investigate the anti-diabetic activity of Tinospora cordifolia (Willd.) (TC) stem extracts (both aqueous and alcoholic) in different dosages (200 and 400 mg/kg b.w.) in streptozotocin diabetic albino rats. The probable mechanism by which TC may act as an anti-hyperglycemic drug was also investigated. Materials and methods: The drug was administered orally for 10 days and 30 days in different groups of animal, with each group containing 6 animals. The efficacy of this drug was compared with the Lante Zinc Insulin (6 U/kg b.w. daily, i.p.) treated diabetic rats. The serum insulin levels, histology of endocrine pancreas and activity of key enzymes of glucose metabolism, i.e. glycogen synthase and glycogen phosphorylase, were studied. Results: Our study clearly showed that TC has significant (P < 0.05) anti-diabetic activity in diabetic animals and has an efficacy of 40% to 80% compared to insulin. TC administration in diabetic animals did not cause any increase in serum insulin levels or regeneration of pancreatic \beta cells but caused increased hepatic glycogen synthase and decreased glycogen phosphorylase activity. Conclusion: The probable mechanism by which TC may act as an anti-hyperglycemic drug is not through insulin secretion like sulfonylureas. It may be through some peripheral mechanisms, such as increasing the glycogen storage in the liver or decreasing the glucose release from the liver.