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

Abstract

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 1 month l-cys (0.5 g 24 h −1, orally) supplementation, pre- (group C) and post-training (group D). Total antioxidant status (TAS) and the biomarker of DNA oxidative damage 8-hydroxy-2-deoxyguanosine (8-OHdG) 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 l −1, 417 ± 90 U l −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 l −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). Conlusions 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.