The Melatonin Attenuates Alloxan Induced Post-Diabetic Testicular Damage and Oxidative Effects in Rats

The aim of this study was to examine the protective effect of melatonin (MLT) on the alloxan-induced post-diabetic testicular damage in rats. Forty-eight Sprague Dawley male rats were divided into four groups (n = 12). Group C received 0.9% saline for 45 days, as control. Group DM (Diabetes Mellitus) was injected by 120 mg/kg single dose alloxan intraperitoneally (IP). Group MLT was treated by 10 mg/kg/d MLT IP for 45 d. Group DM+MLT was treated by 10 mg/kg/d MLT IP for 45 days following alloxan injection. Six animals on days 15 and the remaining 6 on days 45 were sacrificed in each group after the initiation of the study. Testis tissues and blood samples were collected to investigate blood glucose, oxidant and antioxidant statues, sperm parameters, and histopathological and 8-hydroxy-2'-deoxyguanosine (8-OHdG)-immunopositive cell examinations. MLT treatment of diabetic rats prevented the increases in malondialdehyde (MDA) levels and 8-OHdG concentrations, and the decreases in the GSH and SOD levels observed in DM groups. Alloxan administration depressed the sperm concentration, the number of progressively motile spermatozoa, premature acrosome reaction (AR) and calcium ionophore A23187-induced AR rates, without any change in dead and/or abnormal sperm rates in DM group. Histopathological and immunohistochemical observations also revealed that MLT-treated diabetic rats had an enhanced histological architecture and DNA damage in testis. These findings suggest that MLT treatment prevents the testicular damage by declining the oxidative stress, but it did not recover the depressed sperm parameters in diabetic rats.