Özet:

The study’s aim is to investigate the protective effects of olive (Olea europaea L.) leaf ether extract, due to its rich phenolic content and beneficial health effects, on streptozotocin (STZ)-induced oxidative stress in rats. Diabetes in rats was intraperitoneally induced by STZ (40 mg/kg). Following the induction, significant increases in lipid peroxidation, blood glucose, and the levels of the hepatic enzymes (AST, ALP, and ALT) were observed. Moreover, there were significant decreases in GST, GPx, and SOD activities of the diabetic rats. The animals were treated with the ether extracts at two different doses by oral gavage for 14 days. At the end of the treatment, a decrease in lipid peroxidation and the hepatic enzyme levels of the diabetic rats and an increase in the antioxidant enzyme activities were observed. However, these values were not close to normal levels of the healthy rats. Interestingly, there were no significant differences between the blood glucose levels in all the groups throughout the treatment. As a result, our findings have shown that the ether extract of olive leaf partially has a protective role on the STZ-induced oxidative damage in the rats due to inadequate treatment period. The antidiabetic effect of olive leaf might be due to some natural phenolic compounds it contains. In addition, we believe that the leaves could be used as potential therapeutic drugs or dietary supplements in diabetes management. Keywords: Antioxidant, Ether Extract, Olive Leaf, Oxidative Stress, Streptozotocin