Reduction of the incidence of sperm DNA fragmentation by oral antioxidant treatment

Sperm DNA fragmentation is known to compromise male fertility. Previous findings have suggested the implication of oxidative stress in the etiology of this pathological condition. The present study was conducted to find out if the pathologically increased incidence of DNA fragmentation in ejaculated spermatozoa can be reduced by oral treatment with two antioxidants, vitamins C and E. Sixty-four men with unexplained infertility and an elevated (≥ 15%) percentage of DNA-fragmented spermatozoa in the ejaculate were randomized between an antioxidant treatment (1 g vitamin C and 1 g vitamin E daily for 2 months) group and a placebo group. Sperm DNA fragmentation was evaluated by terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling assay before and after treatment. No differences in basic sperm parameters were found between the antioxidant treatment and the placebo group before or after treatment. However, the percentage of DNA-fragmented spermatozoa was markedly reduced (P < .001) in the antioxidant treatment group after the treatment (9.1 ± 7.2) as compared with the pretreatment values (22.1 ± 7.7). No difference in the pretreatment and posttreatment incidence of sperm DNA fragmentation was observed in the placebo group. These data show that sperm DNA damage can be efficiently treated with oral antioxidants administered during a relatively short time period.