Effects of N-acetylcysteine supplementation on cellular damage and oxidative stress indicators in volleyball athletes

Abstract

The purpose of this study was to evaluate the effects of N-acetylcyste-ine (NAC) supplementation on cellular damage and oxidative stress in-dicators in volleyball athletes. Twenty male volleyball athletes at nation-al level performed a physical training session and were divided into 2 groups, which for 7 days took the placebo substance or NAC. After 7 days the athletes repeated the same training session. In both sessions, blood samples were collected 30 min before and immediately after the training session to measure cellular damage and oxidative stress mark-ers. The main results show that, although higher concentrations of glu-tathione peroxidase and superoxide dismutase were observed in post-session 1 than those in postsession 2, the other markers showed an in-crease in antioxidant action after supplementation of NAC, once the ef-fect of experimental conditions (P=0.030) were observed in: time effect (P < 0.001) and interaction (P=0.019) for total glutathione; time effect (P < 0.001) and interaction (P < 0.001) for reduced glutathione; and time effect (P < 0.001) for ferric-reducing antioxidant potential. The oxidant action indicated by the protein carbonyl was higher in the placebo group than in the NAC group (P=0.028), but a time effect (P < 0.001) for the thiobarbituric acid reactive substances showed lower values in presession 1 than in presession 2. For the cellular damage markers, an-tagonistic results between markers were found. Based in the results, the supplementation of NAC during a short period was effective in re-ducing oxidant action and increasing antioxidant action. However, con-clusive alterations in the responses of the cellular damage markers were not obtained.