title: Effect of Tai Chi exercise on DNA damage, antioxidant enzymes, and oxidative stress in middle-age adults.
abstract: BACKGROUND
  The biochemical mechanisms involving oxidative stress to explain the relationship between exercise and healthy aging are still unclear.
  
  
  METHODS
  Tai Chi participants and matched sedentary volunteers age 45 and above were enrolled. Glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) activities; levels of DNA damage using the comet assay; and malondialdehyde (MDA) and advanced glycation end products (AGE) were determined at 0, 6, and 12 months.
  
  
  RESULTS
  Tai Chi subjects had decreased normal and increased mildly damaged DNA with elevated GPx activity after 6 months (n=25). Plasma MDA and AGE concentrations decreased significantly after 12 months (n=15) accompanied by increased SOD activity. This may be attributed to the hormesis effect, whereby mild induction of oxidative stress at the first 6 months of exercise resulted in stimulation of antioxidant defenses. These parameters were unchanged in the sedentary subjects in the first 6 months (n=27) except for elevated SOD activity. After 12 months, the sedentary subjects (n=17) had decreased normal DNA and increased severely damaged DNA with unaltered MDA and AGE levels while SOD and GPx activities were significantly elevated.
  
  
  CONCLUSIONS
  Regular Tai Chi exercise stimulated endogenous antioxidant enzymes and reduced oxidative damage markers.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
authors.forename: J A
authors.initials: JA
authors.lastname: Goon
authors.forename: A H Noor
authors.initials: AH
authors.lastname: Aini
authors.forename: M
authors.initials: M
authors.lastname: Musalmah
authors.forename: M Y Yasmin
authors.initials: MY
authors.lastname: Anum
authors.forename: W M Wan
authors.initials: WM
authors.lastname: Nazaimoon
authors.forename: W Z Wan
authors.initials: WZ
authors.lastname: Ngah
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D002374:Catalase / Q000097:blood; D020552:Comet Assay; D004249:DNA Damage; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D017127:Glycation End Products, Advanced / Q000097:blood; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D018384:Oxidative Stress; D018709:Statistics, Nonparametric; D013482:Superoxide Dismutase / Q000097:blood; D026302:Tai Ji
chemical_list: D017127:Glycation End Products, Advanced; D008315:Malondialdehyde; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase