Oleuropein protects against ethanol-induced oxidative stress and modulates sperm quality in the rat testis

The aim of the present study was to evaluate the antioxidant properties of oleuropein on ethanol-induced oxidative stress in the rat testis. 32 adult male Sprague-Dawley rats were divided into four equal groups: the first group as a control, the second group of rats were given ethanol (4 g/kg), the third group received oleuropein (15 mg/kg), and the fourth group of rats were supplemented of oleuropein (15 mg/kg) and after 120 min were ingested via ethanol (4 g/kg) orally. Oleuropein could prevent the reduction of motility and plasma membrane integrity of the spermatozoa against ethanol-induced oxidative stress in treated rats (P < 0.05). While, thiobarbituric acid reactive substances (as a lipid peroxidation marker) concentration was decreased significantly in the oleuropein plus ethanol group compared to the ethanol group (P < 0.05). Notably, glutathione peroxidase and superoxide dismutase activity increased significantly in the ethanol-treated animals compared to controls and total glutathione (GSH-content) increased significantly in ethanol-treated rats compared to the oleuropein group. Our findings suggest that oleuropein possesses beneficial antioxidant effects on ethanol-induced sperm toxicity, subsequently enhancing sperm motility and plasma membrane integrity.