PGC1α in Skeletal Muscle Mediates Anti-Obesity Effects of Soy Isoflavones

Obesity, a factor increasing the risk of metabolic diseases such as type 2 diabetes, dyslipidemia, and hypertension, can be reduced by the intake of soy isoflavones. In this study, we investigated whether skeletal muscle PGC1α, a transcriptional activator known to promote a variety of exercise-related metabolic processes, is involved in the anti-obesity effects of soy isoflavones using skeletal muscle-specific PGC1α knockout mice. The results showed that the intake of soy isoflavones reduced white adipose tissue weight and increased expression of energy metabolism-related genes such as mitochondrial function, lipolysis, and fatty acid oxidation in skeletal muscle. However, these effects were not observed in skeletal muscle-specific PGC1α knockout mice. In C2C12 myoblasts with overexpressing PGC1α, soy isoflavone treatment increased energy-metabolism related genes. Therefore, PGC1α of skeletal muscle is likely to be involved in the anti-obesity effects of soy isoflavones.