Ghrelin promotes antioxidant enzyme activity and reduces lipid peroxidation in the rat ovary

Antioxidant properties of ghrelin have been recently reported on various oxidative stresses in limited tissues. This study was set to examine the possible antioxidative effects of ghrelin in rat ovarian tissue. Twenty eight female adult Wistar rats were randomly allocated into control and treatment groups. Treatment group (n = 14) received 2 nmol of ghrelin as subcutaneous injection for 14 consecutive days or vehicle (physiological saline) to the control rats. The animals from both groups were equally killed on days 9 and 14 after beginning of ghrelin injection (n = 7 from each group on each day) and their ovaries were taken for later antioxidant enzyme activity assays as well as measurement of glutathione content and thiobarbituric acid reactive substances (TBARS) level. Superoxide dismutase activity was significantly higher on days 9 (P < 0.05) and 14 (P < 0.01) in the treated group compared to the control rats. By contrast, lipid peroxidation, as TBARS value, reduced significantly on both experimental days in the ghrelin-exposed animals (P < 0.05). Although, the mean activity of catalase and glutathione content was greater in the treated rats, however, the differences were not statistically significant. Slight changes occurred in glutathione peroxidase activity during the experimental period and there were no differences either on day 9 or on day 14 between groups. In conclusion, the results of the present investigation indicate for the first time the novel evidence of antioxidant properties of ghrelin in the rat ovary.