title: 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.
  
  
  OBJECTIVE
  To investigate the effect of L-cysteine (L-cys) supplementation on DNA oxidative damage found in basketball players after forced training.
  
  
  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+/-88U l(-1), p<0.001, respectively). 8-OH dG 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.
authors.affiliation: Department of Experimental Physiology, Medical School, University of Athens, P.O. Box 65257, GR-15401 Athens, Greece. stsakir@cc.uoa.gr
authors.forename: Stylianos
authors.initials: S
authors.lastname: Tsakiris
authors.forename: Theodore
authors.initials: T
authors.lastname: Parthimos
authors.forename: Nickolaos
authors.initials: N
authors.lastname: Parthimos
authors.forename: Theodore
authors.initials: T
authors.lastname: Tsakiris
authors.forename: Kleopatra H
authors.initials: KH
authors.lastname: Schulpis
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000293:Adolescent; D001490:Basketball; D003402:Creatine Kinase / Q000097:blood; D003545:Cysteine / Q000627:therapeutic use*; D004247:DNA / Q000378:metabolism*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000097:blood; D019587:Dietary Supplements; D005609:Free Radicals / Q000378:metabolism; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D010084:Oxidation-Reduction; D005082:Physical Exertion / Q000187:drug effects / Q000502:physiology*
chemical_list: D005609:Free Radicals; D000080242:8-Hydroxy-2'-Deoxyguanosine; D004247:DNA; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase; D003849:Deoxyguanosine; D003545:Cysteine