Efeito da suplementação de ácido α-lipóico sobre parâmetros do sistema antioxidante no pós-exercício de camundongos treinados

Abstract

The regular practice of physical activity associated with a balanced diet is important in health promotion. However, the physical exercises of high intensity or exhaustive exercises can cause damage, like chronic fatigue and overtraining, partially due to the high synthesis of reactive oxygen species. In contrast, physical training exerts protective capacity of this adaptive response through the production of endogenous antioxidants. The antioxidant system is a machinery that controls the actions of free radicals for the maintenance of cellular homeostasis of aerobic organisms, and may be enzymatic and nonenzymatic, endogenous and exogenous. The α-lipoic acid and its reduced form, dihydrolipoic acid, act as potent antioxidant and eliminates free radicals. This study aimed to evaluate the effect of supplementation of α-lipoic acid on biomarkers of oxidative stress in trained mice in post-exhaustive exercise. Training consisted of 6 weeks swimming. At the last day an exhaustive session with 10% overload the weight attached to the tail of the animal was released. Supplemented group animals received 100mg/kg/day α-lipoic acid, while the Control group received placebo vehicle. Euthanasia was in 3 different times, Basal (animals that have not performed exhaustive exercise), 0 and 4h post-exhaustion. The dosages of biomarkers of oxidative stress were performed, yielding a simultaneous decrease of the concentrations of reduced glutathione (GSH), vitamin E 4h after exhaustive exercise in the Supplemented group, suggesting the use of these for the reduction of lipid peroxidation, reducing perceived by the thiobarbituric acidreactive substances (TBARS) in the same group and in the experimental protocol period. In contrast, there was an increase of nitric oxide (NO) in the Supplemented group and the total antioxidant capacity remained unchanged. Thus, only the latter two parameters go against our hypothesis. Thus, it is concluded that supplementation with a-lipoic acid resulted in the protection against oxidative stress induced by exhaustive exercise.