title: alpha-Lipoic acid modulates thiol antioxidant defenses and attenuates exercise-induced oxidative stress in standardbred trotters.
abstract: Several micronutrient supplementation strategies are used to cope with oxidative stress, although their benefits have recently been questioned. The aim of the present study was to examine the effects of DL-alpha-lipoic acid (LA) in response to acute exercise and during recovery in horses. Six standardbred trotters were tested on the treadmill before and after 5-week LA supplementation (25 mg/kg body weight/day). According to electron paramagnetic resonance measurements, strenuous aerobic exercise increased significantly free radical formation in the gluteus medius muscle, which was prevented by LA supplementation. The activities of thioredoxin reductase and glutathione reductase in muscle were significantly increased in LA-treated horses, but neither LA nor exercise affected muscle thioredoxin activity. LA increased the concentration of total glutathione in muscle at rest and during recovery. Treatment with LA blunted the exercise-induced increase in plasma oxygen radical absorbance capacity and decreased the post-exercise levels of lipid hydroperoxides in plasma and malondialdehyde in plasma and in muscle. These findings suggest that LA enhances thiol antioxidant defences and decreases exercise-induced oxidative stress in skeletal muscle.
authors: Institute of Biomedicine, Physiology, University of Kuopio, PO Box 1627, Kuopio, Finland.
authors: Susanna
authors: S
authors: Kinnunen
authors: Niku
authors: N
authors: Oksala
authors: Seppo
authors: S
authors: Hyyppä
authors: Chandan K
authors: CK
authors: Sen
authors: Zsolt
authors: Z
authors: Radak
authors: David E
authors: DE
authors: Laaksonen
authors: Bernadett
authors: B
authors: Szabó
authors: Judit
authors: J
authors: Jakus
authors: Mustafa
authors: M
authors: Atalay
mesh_terms: D000818:Animals; D019587:Dietary Supplements; D004353:Drug Evaluation, Preclinical / Q000662:veterinary; D004578:Electron Spin Resonance Spectroscopy; D005080:Exercise Test; D005260:Female; D005978:Glutathione / Q000378:metabolism; D006736:Horses / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010805:Physical Conditioning, Animal / Q000502:physiology*; D050050:Protein Carbonylation / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D008063:Thioctic Acid / Q000494:pharmacology*; D013879:Thioredoxins / Q000032:analysis
chemical_list: D009124:Muscle Proteins; D017382:Reactive Oxygen Species; D008315:Malondialdehyde; D013879:Thioredoxins; D008063:Thioctic Acid; D005978:Glutathione