The beneficial effect of L-cysteine supplementation on DNA oxidation induced by forced training

Background: Forced training is closely implicated with free radicals production and indication of tissue damage as well as DNA oxidation. Aim: To investigate the effect Of L-Cysteine (L-CYS) supplementation on DNA oxidative damage found in basketball players after forced training. Subjects and methods: Blood was obtained from 10 players pre-game (group A), post-game (group B) and after I month L-CYS (0.5 g 24 h(-1), orally) supplementation, pre- (group Q and post-training (group D). Total antioxidant status (TAS) and the biomarker of DNA oxidative damage 8-hydroxy-2-deoxyguanosine (8-OGdG) as well as creatine kinase (CK) and lactate dehydrogenase (LDH) were measured with commercial kits. Results: TAS was increased in the groups with L-cys (group C and group D). Post-exercise 8-OHdG levels, CK and LDH were remarkably lower (0.16 +/- 0.03 ng ml(-1), 115 +/- 15 U I-1, 417 +/- 90 U I-1, respectively) in group D than those in group B (0.36 +/- 0.05 ng ml(-1), 286 +/- 12 U l(-1), 688 +/- 88 U I-1, p < 0.001, respectively). 8-OHdG levels were negatively correlated with TAS(r = -0.718, p < 0.01) and positively with CK levels(r = 0.590, p +/- 0.01). Conclusions: L-CYS supplementation in basketball players may reduce DNA damage induced by training. The sulfur-containing amino acid may protect muscle cells "death" by increasing TAS and the cellular defense against oxidative stress. (c) 2006 Elsevier Ltd. All rights reserved.