Efeito da suplementação com benfotiamina sobre parâmetros metabólicos e desempenho de endurance de camundongos submetidos a treinamento de natação

Abstract

Introduction: Physical exercises increase energy demand, making it necessary an adequate nutrients intake to improve energy production, aiming to promote better recovery and optimize adaptive processes. Thiamine diphosphate (TDP) is an essential cofactor for the functioning of the enzymes pyruvate dehydrogenase (PDH), α-ketoglutarate dehydrogenase (OGDH), and transketolase (TKT), which are fundamentals in energy metabolism. Benfotiamine is a synthetic analogue of thiamine capable of promoting a greater bioavailability of TDP compared to other thiamine salts. Objective: The objective of this study was to evaluate the effects of supplementation with benfotiamine on metabolic and performance parameters in mice, physical training of endurance. 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). Benfotiamine was added to the AIN-93 diet (500mg/Kg). The training comprised 6 weeks of endurance swimming training. The exhaustion test was the last swimming session with an overload of 5% of the body weight attached to the tail. The plasma lactate concentration was measured before and immediately after the exhaustion test. 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. The thiamine concentration in erythrocytes and in gastrocnemius muscle was assessed using high performance liquid chromatography. The expression of the genes PDHa1 and OGDH in gastrocnemius muscle was evaluated by reverse transcriptase-Reaction in the polymerase chain in real time (qRT-PCR). Pyruvic, lactic and hydroxybutyric acids were quantified in muscle by gas chromatography coupled to the mass spectrometer (GC-MS). Results: Supplemented animals showed higher levels of thiamine, thiamine monophosphate and thiamine diphosphate in the erythrocytes and in the muscle. In the tibialis muscle, lipid peroxidation was higher in the Sta-Sed group was higher while in the heart, lipid peroxidation in the Sta-Sed and Ben-Tr groups was higher than in the Ben-Sed group. The carbonyl content in the muscle 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. The level of total thiols was lower in the Ben-Sed group than in the Sta-Tr. In the heart, the level of total thiols washigher in the Ben-Sed group than in the Ben-Tr. The concentration of non-protein thiols in the muscle was higher in the Ben-Sed group than in the Ben-Tr, whereas in the heart, concentration of non-protein thiols of Sta-Tr group was lower than in the Sta-Sed. There was no difference in gene expression between all groups. The muscle of the Ben-Tr animals showed higher concentrations of lactic acid and hydroxybutyric acid than sedentary animals. The lactic acid: pyruvic acid ratio was higher in the trained animals. There was no difference in endurance capacity between the Pad-Tr and Ben-Tr groups. Similarly, the final lactate concentration was also no different between groups. Conclusion: Oral supplementation with benfotiamine increases the concentration of thiamine and its ethers in the erythrocytes and in the gastrocnemius muscle. It is an efficient antioxidant against oxidative stress in the anterior tibial muscle and in the heart of animals submitted to endurance training. However, it is not able to affect the expression of thiamine-dependent enzyme genes in gastrocnemius muscle. The supplementation increased the pyruvate catabolism in muscle of trained mice, but did not affect endurance performance.