title: Effects of α-lipoic acid on mtDNA damage after isolated muscle contractions.
abstract: BACKGROUND
  Although pharmacological antioxidants have previously been investigated for a prophylactic effect against exercise oxidative stress, it is not known if α-lipoic acid supplementation can protect against DNA damage after high-intensity isolated quadriceps exercise. This randomized controlled investigation was designed to test the hypothesis that 14 d of α-lipoic acid supplementation can attenuate exercise-induced oxidative stress.
  
  
  METHODS
  Twelve (n = 12) apparently healthy male participants (age = 28 ± 10 yr, stature = 177 ± 12 cm and body mass = 81 ± 15 kg) were randomly assigned to receive either a daily supplement of 1000 mg of α-lipoic acid (2 × 500-mg tablets) for 14 d (n = 6) or receive no supplement (n = 6) in a double-blinded experimental approach. Blood and muscle biopsy tissue samples were taken at rest and after the completion of 100 isolated and continuous maximal knee extension (minimum force = 200 N, speed of contraction = 60° · s(-1)).
  
  
  RESULTS
  Exercise increased mitochondrial 8-hydroxy-2-deoxyguanosine (8-OHdG) concentration in both groups (P < 0.05 vs rest) with a concomitant decrease in total antioxidant capacity (P < 0.05 vs rest). There was a marked increase in blood total antioxidant capacity after oral α-lipoic acid supplementation (P < 0.05 vs nonsupplemented), whereas DNA damage (Comet assay and 8-OHdG), lipid peroxidation, and hydrogen peroxide increased after exercise in the nonsupplemented group only (P < 0.05 vs supplemented). Exercise increased protein oxidation in both groups (P < 0.05 vs rest).
  
  
  CONCLUSIONS
  These findings suggest that short-term α-lipoic acid supplementation can selectively protect DNA (but not in muscle mitochondria) and lipids against exercise-induced oxidative stress.
authors.affiliation: Department of Sport, Health & Exercise Science, University of Hull, Cottingham Road, Kingston-upon-Hull, United Kingdom.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Fogarty
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Devito
authors.forename: Ciara M
authors.initials: CM
authors.lastname: Hughes
authors.forename: George
authors.initials: G
authors.lastname: Burke
authors.forename: John C
authors.initials: JC
authors.lastname: Brown
authors.forename: Jane
authors.initials: J
authors.lastname: McEneny
authors.forename: David
authors.initials: D
authors.lastname: Brown
authors.forename: Conor
authors.initials: C
authors.lastname: McClean
authors.forename: Gareth W
authors.initials: GW
authors.lastname: Davison
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D000975:Antioxidants / Q000627:therapeutic use*; D004249:DNA Damage / Q000187:drug effects*; D004272:DNA, Mitochondrial / Q000187:drug effects*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation; D008297:Male; D008931:Mitochondria, Muscle / Q000187:drug effects* / Q000378:metabolism; D009119:Muscle Contraction / Q000502:physiology*; D018384:Oxidative Stress / Q000187:drug effects; D008063:Thioctic Acid / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D000975:Antioxidants; D004272:DNA, Mitochondrial; D008063:Thioctic Acid; D000080242:8-Hydroxy-2'-Deoxyguanosine; D006861:Hydrogen Peroxide; D003849:Deoxyguanosine