Protective role of silibinin over nickel sulfate-induced reproductive toxicity in male rats.

Nickel damages the male reproductive system. We investigated the beneficial effects of silibinin which has metal-chelating and antioxidant properties over nickel toxicity. Both antioxidative effects in testes and overall effects related to sperm motility, membrane and acrosome integrity of orally administered Silibinin were evaluated against the harmful effects of 30 day of intraperitoneal nickel sulfate (5 mg/kg/day) administration in rats. Male rats were randomized into control (Group1; n=6) and three experimental groups (n=6, each): Group2 Nickel sulfate (5 mg/kg/day), Group3 Silibinin (150 mg/kg/day), and Group 4 Nickel sulfate (5 mg/kg/day) + Silibinin (150 mg/kg/day). We found higher sperm motility, viable sperm and total sperm count in Groups 3 and 4 than the Group 2 treatment groups and the percentage of abnormal spermatozoa was similar in both groups (Groups 2 and 4). Increased apoptosis, activation of caspase3, 8, 9 and TUNEL were detected in Group 2. However, activation of caspase3, 8, 9 and TUNEL was reduced in Group 4. The protective effects of silibinin were demonstrated on histopathologic findings and some sperm parameters (sperm motility percentage, viable spermatozoa, sperm count, and abnormal spermatozoa percentage) in rats exposed to nickel.

The protective effect of melatonin on sperm quality in rat after radioiodine treatment.

This study was designed to investigate the potential radioprotective impact of melatonin on the testicular tissue and sperm quality in rat given radioactive iodine (RAI) therapy. Thirty-six male Wistar albino rats were randomly divided into three groups as untreated control (Group 1); oral radioiodine group (RAI, 111 MBq, administrated rats); and RAI+melatonin group (oral radioiodine and intraperitoneal 12 mg/kg/day melatonin, starting 2 days before and continuing for 1 week after oral RAI administration). Twenty-four hours after the injection of the last melatonin dose, blood samples were taken for hormone analyses and the determination of the total antioxidant capacity. Sperm samples taken from the cauda epididymis were examined for spermatological parameters. Tissue samples taken from the rat testes were stained by TUNEL assay and with haematoxylin-eosin to detect apoptosis and histological alterations. It was demonstrated a significant decrease in epididymal spermatozoa viability and motility in all of the treatment groups, in comparison with the control group (p < .001). A significant decrease was also detected in sperm DNA fragmentation, follicle-stimulating hormone (FSH) level and the index of apoptotic germ cells in the RAI+melatonin group when compared to the radioiodine group. It was concluded that melatonin prevents the adverse affects of RAI on apoptosis and spermatozoa quality.