Mali, et al.: Antidiabetic Effect of GarcinolThe objective of the present study was to investigate the antidiabetic effect of garcinol on streptozotocininduced diabetic rats. Acute toxicity of garcinol was studied according to the guidelines of Organization for Economic Co-operation and Development. Oral glucose tolerance test was used as a preliminary screening method. Diabetes was induced in rats by intraperitoneal injection of streptozotocin (60 mg/kg). After induction of diabetes, rats were treated with garcinol (25, 50 and 100 mg/kg) and metformin (100 mg/ kg) for 28 days. Blood samples were collected for estimating biochemical parameters. Administration of garcinol caused significant reduction in elevated levels of blood glucose, glycosyated hemoglobin and lipids in diabetic rats. Histopathological study revealed regeneration of pancreatic β cells in the garcinol-treated groups. These results indicated that garcinol showed significant antidiabetic and lipid-lowering effects in streptozotocin-induced diabetes rats.