Effect of Coenzyme Q10 supplementation on antioxidant enzymes activity and oxidative stress of seminal plasma: a double-blind randomised clinical trial.

Low seminal plasma concentrations of coenzyme Q10 (CoQ10) have been correlated with impaired sperm parameters, but the exact mechanism remains of dominating interest. This randomised, placebo-controlled study examined the effect of CoQ10 on catalase, superoxide dismutase (SOD) and F2 -isoprostanes in seminal plasma in infertile men and their relation with CoQ10 concentration. Sixty infertile men with idiopathic oligoasthenoteratozoospermia (OAT) were randomised to receive 200 mg d(-1) of CoQ10 or placebo for 3 months. 47 persons of them completed the study. Semen analysis, anthropometric measurements, diet and physical activity assessment were performed for subjects before and after treatment. Independent and paired t-test, chi-square test and ancova were compared outcomes of supplementation between two groups. CoQ10 levels increased from 44.74 ± 36.47 to 68.17 ± 42.41 ng ml(-1) following supplementation in CoQ10 (P < 0.001). CoQ10 group had higher catalase and SOD activity than the placebo group. There was a significant positive correlation between CoQ10 concentration and normal sperm morphology (P = 0.037), catalase (P = 0.041) and SOD (P < 0.001). Significant difference was shown between the mean of changes in seminal plasma 8-isoprostane in two groups (P = 0.003) after supplementation. Three-month supplementation with CoQ10 in OAT infertile men can attenuate oxidative stress in seminal plasma and improve semen parameters and antioxidant enzymes activity.