Comparação do treinamento físico de quatro e oito semanas sobre atividade da cadeia transportadora de elétrons e marcadores de estresse oxidativo em fígado de camundongos

Benfotiamine supplementation prevents oxidative stress in anterior tibialis muscle and heart

OBJECTIVE

This study aimed to evaluate the influence of oral supplementation with benfotiamine on oxidative stress in the liver, heart and muscles of endurance-trained mice.

METHODS

Twenty-five male BALB/c mice were allocated to the following treatment groups: standard diet and sedentary activity (Sta-Sed), benfotiamine-supplemented diet and sedentary activity (Ben-Sed), standard diet and training activity (Sta-Tr) and benfotiamine-supplemented diet and training activity (Ben-Tr). The training comprised 6 weeks of endurance swimming training. The concentration of thiobarbituric acid reactive substances (TBARS), carbonylated proteins, total thiols and non-protein thiols was analyzed in the liver, heart and tibialis anterior muscle.

RESULTS

In the muscle, TBARS concentration in the Sta-Sed group was higher than that in other groups; in the heart, TBARS concentration in the Sta-Sed and Ben-Tr groups was higher than that in the Ben-Sed group. The carbonyl content of the muscle tissues was higher in the Sta-Sed group than in both supplemented groups. In liver, the carbonyl content was lower in the Ben-Sed group than in the Sta-Sed group. The level of total thiols was lower in the Ben-Sed group than in the Sta-Tr group. In the heart, the level of total thiols was higher in the Ben-Sed group than in the Ben-Tr group. The concentration of non-protein thiols in the muscle was higher in the Ben-Sed group than in the Ben-Tr group, whereas in the heart, concentration of non-protein thiols of Sta-Tr group was lower than that of Sta-Sed group.

CONCLUSION

The results show that benfotiamine is an efficient antioxidant for the anterior tibialis muscle and heart; however, swimming training did not alter redox status.

Creatine supplementation and oxidative stress in rat liver

BACKGROUND

The objective of this study was to determine the effects of creatine supplementation on liver biomarkers of oxidative stress in exercise-trained rats.

METHODS

Forty 90-day-old adult male Wistar rats were assigned to four groups for the eight-week experiment. Control group (C) rats received a balanced control diet; creatine control group (CCr) rats received a balanced diet supplemented with 2% creatine; trained group (T) rats received a balanced diet and intense exercise training equivalent to the maximal lactate steady state phase; and supplemented-trained (TCr) rats were given a balanced diet supplemented with 2% creatine and subjected to intense exercise training equivalent to the maximal lactate steady state phase. At the end of the experimental period, concentrations of creatine, hydrogen peroxide (H2O2) and thiobarbituric acid reactive substances (TBARS) were measured as well as the enzyme activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-GPx) and catalase (CAT). Liver tissue levels of reduced glutathione (GSH), oxidized glutathione (GSSG) and the GSH/GSSG ratio were also determined.

RESULTS

Hepatic creatine levels were highest in the CCr and TCr groups with increased concentration of H2O2 observed in the T and TCr animal groups. SOD activity was decreased in the TCr group. GSH-GPx activity was increased in the T and TCr groups while CAT was elevated in the CCr and TCr groups. GSH, GGS and the GSH/GSSG ratio did not differ between all animal subsets.

CONCLUSIONS

Our results demonstrate that creatine supplementation acts in an additive manner to physical training to raise antioxidant enzymes in rat liver. However, because markers of liver oxidative stress were unchanged, this finding may also indicate that training-induced oxidative stress cannot be ameliorated by creatine supplementation.