RESUMEN
Male reproductive dysfunction is a common complication of diabetes mellitus. Trifolium pratense exhibits antioxidant and antidiabetic effects. We investigated the effects of an extract of T. pratense on serum antioxidant status, sperm characteristics, testicular tissue changes and testosterone level in diabetic rats. Male Wistar rats were divided into six groups: 1, untreated control; 2, diabetic; 3 and 4, 100 or 200 mg/kg T. pratense extract treated, respectively; 5 and 6, diabetic 100 or 200 mg/kg T. pratense extract treated, respectively. Diabetes was induced by intraperitoneal injection of streptozotocin. After 3 weeks, serum glucose, testosterone and nitric oxide (NO); sperm parameters; testicular histology and total antioxidant capacity (TAC) were evaluated. In diabetic rats treated with T. pratense extract, sperm motility, count and viability, as well as TAC and testosterone were increased significantly compared to untreated diabetic rats, while serum NO and bcl-2 and p53 expression was decreased significantly compared to untreated diabetic rats. T. pratense extract reduced testicular tissue destruction caused by diabetes.