title: Mitigation of oxidative damage by green tea polyphenols and Tai Chi exercise in postmenopausal women with osteopenia.
abstract: BACKGROUND
  Osteoporosis is a degenerative bone disease predominantly in postmenopausal women. Green tea polyphenols (GTP) and Tai Chi (TC) have been shown to be beneficial on human bone health. This study examined the efficacy of GTP and TC on mitigation of oxidative damage in postmenopausal women with osteopenia.
  
  
  METHODS
  A 6-month randomized and placebo-controlled clinical trial was conducted in 171 postmenopausal women with osteopenia, who were recruited from Lubbock County, Texas. These participants were treated with placebo, GTP (500 mg daily), placebo + TC (60-minute group exercise, 3 times/week), or GTP (500 mg daily) + TC (60-minute group exercise, 3 times/week), respectively. Their blood and urine samples were collected at the baseline, 1-, 3- and 6-months during intervention for assessing levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), an oxidative DNA damage biomarker, and concentrations of serum and urine GTP components.
  
  
  RESULTS
  The elevated concentrations of serum and urinary GTP components demonstrated a good adherence for the trial. A significant reduction of urinary 8-OHdG concentrations was found in all three treated groups during 3-month (P<0.001) and 6-month (P<0.001) intervention, as compared to the placebo group. The significant time- and dose-effects on mitigation of the oxidative damage biomarker were also found for GTP, TC, and GTP+TC intervened groups.
  
  
  CONCLUSIONS
  Our study demonstrated that GTP and TC interventions were effective strategies of reducing the levels of oxidative stress, a putative mechanism for osteoporosis in postmenopausal women, and more importantly, working in an additive manner, which holds the potential as alternative tools to improve bone health in this population.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT00625391.
authors.affiliation: Department of Environmental Health Science, University of Georgia, Athens, Georgia, USA.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Qian
authors.forename: Kathy
authors.initials: K
authors.lastname: Xue
authors.forename: Lili
authors.initials: L
authors.lastname: Tang
authors.forename: Franklin
authors.initials: F
authors.lastname: Wang
authors.forename: Xiao
authors.initials: X
authors.lastname: Song
authors.forename: Ming-Chien
authors.initials: MC
authors.lastname: Chyu
authors.forename: Barbara C
authors.initials: BC
authors.lastname: Pence
authors.forename: Chwan-Li
authors.initials: CL
authors.lastname: Shen
authors.forename: Jia-Sheng
authors.initials: JS
authors.lastname: Wang
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000368:Aged; D015415:Biomarkers / Q000652:urine; D050071:Bone Density Conservation Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D001851:Bone Diseases, Metabolic / Q000628:therapy* / Q000652:urine; D028241:Camellia sinensis; D003131:Combined Modality Therapy; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D005260:Female; D006801:Humans; D008875:Middle Aged; D018384:Oxidative Stress; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage* / Q000493:pharmacokinetics; D059808:Polyphenols / Q000008:administration & dosage* / Q000493:pharmacokinetics; D017698:Postmenopause; D026302:Tai Ji; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D010936:Plant Extracts; D059808:Polyphenols; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine