Streptozotocin-Induced Oxidative Stress in Rats: The Protective Role of Olive Leaf Extract

This paper investigates the antidiabetic and antioxidant effects of olive leaf extract (OLE) prepared in ethanol upon Streptozotocin (STZ)-induced diabetic rats. The rats were divided into five groups (control, OLE, 40 mg/kg STZ, 0.25 g/kg OLE + STZ, and 0.5 g/kg OLE + STZ). The blood of rats was taken for determination of glucose levels besides oxidative activities (superoxide dismutase-SOD, glutathione peroxidase-GPx, glutathione-S transferase-GST activities, and malondialdehyde-MDA) and biochemical parameters (alanine transaminase-ALT, aspartate transaminase-AST, and alkaline phosphatase-ALP). While ALP, AST, ALT, and MDA levels showed an increase, SOD, GPx, and GST levels decreased in Group STZ compared to Control Group. When compared to the group given only STZ, OLE played a significant role in decreasing MDA, ALT, AST, and ALP levels, apart from increasing GPx, and GST following treatment of diabetic rats. As a result, the in vivo data obtained have shown that the OLE has an antidiabetic effect thanks to restricting oxidative stress and reinforcing antioxidant activities.