Alpha-Tocopherol May Protect Hepatocytes Against Oxidative Damage Induced by Endurance Training in Growing Organisms

Background. Training-induced oxidative stress can be reduced by alpha-tocopherol. Adequate intake of alpha-tocopherol could have health benefits for previously untrained young subjects. Objectives. The aim of this study was to determine the effects of training and different doses of alpha-tocopherol on exercise-induced oxidative stress in rat livers. Material and Methods. Young male Wistar rats (n = 40) were randomly divided into eight groups (undergoing training and not undergoing training, given orally administered alpha-tocopherol doses of 0, 0.5, 1.0 and 4.0 mg). Every day for 10 consecutive days, the rats in the training groups ran for 15 min on a treadmill at 20 m/min to induce oxidative stress. Hepatic oxidative stress was evaluated based on the liver concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and thiobarbituric acid reactive substances (TBARS). Results. The liver concentrations of alpha-tocopherol were significantly influenced by alpha-tocopherol doses (p < 0.001) and physical exercise (p < 0.001). The liver concentrations of alpha-tocopherol increased in response to the highest dose (4 mg/d) of alpha-tocopherol in the non-training groups. In the training groups, the liver concentrations of alpha-tocopherol were independent of the dose. The levels of TBARS, a marker of lipid peroxidation, were lowest in the training and non-training rats administered 4.0 mg of alpha-tocopherol. Physical exercise and alpha-tocopherol doses significantly influenced TBARS concentrations (p = 0.004, p < 0.05). Conclusions. The results of this study indicate that running training causes lipids peroxidation and reduces alpha-tocopherol levels in the liver, but it does not contribute to DNA damage. Increased liver concentrations of alpha-tocopherol were found to exert a protective effect against oxidative damage induced by endurance training. An adequate intake of alpha-tocopherol is important for previously untrained young subjects