Effect of (-)-epicatechin on cardiac and skeletal muscle from high fat fed mice: a comparative study

LAURA FISCHERMAN; CESAR G FRAGA; IVANA RUKAVINA MIKUSIC; MÓNICA GALLEANO; BARBARA PIOTRKOWSKI; LAURA VALDEZ

Mar del Plata

Congreso; Reunion Anual de la Sociedad de Investigacion Clinica; 2019

Sociedades de Biociencia: SAIC, SAFE, SAB, SAP, NANOMED-ar, AACyTAL, HCS

INTRODUCTION: It was shown that diet supplementation with (−)-epicatechin (EC) ameliorates changes observed insulin-triggered signaling cascades, in adipose and liver tissues of high-fat fed mice. Because muscle is the main tissue involved in glucose homeostasis, the relationship between insulin resistance and heart and skeletal muscle is under discussion. OBJECTIVE: this study evaluates the effects of EC on cardiac and skeletal muscle mitochondrial function from high-fat fed mice. METHODS: Male C57BL6 mice were fed for 15 w with diets containing 10% total calories from fat (C), 60% total calories from fat (HF), C diet supplemented with EC to provide 20 mg EC/kg body (CE), and HF diet plus same amount of EC (HFE). RESULTS: Mitochondrial respiratory complexes I-III, II-III, and IV activities were higher in cardiac (27%, 24% and 27%) and skeletal muscle (28%, 43% and 43%) from HF compared to C mice. EC supplementation prevented the increase observed in skeletal muscle mitochondrial respiratory parameters in high-fat fed mice. This effect was not observed in mitochondria from cardiac muscle. Tfam and PGC-1alpha expressions were similar among groups, suggesting that de novo synthesis of mitochondria was not altered with treatments. The expression of the uncoupling protein UCP3 was higher in HF and HFE respect to C and CE groups in cardiac and skeletal muscle. Insulin receptor protein levels were similar in all groups, in both tissues. CONCLUSION: Although the mitochondrial dysfunction in response to HF diet was observed in cardiac and skeletal muscle of high-fat fed mice, EC protective effects were restricted to skeletal muscle. Support: UBACyT 20020170100586BA (MG), 20020160100132BA (CGF), PIP-CONICET 11220170100585CO (MG).