Salsalate Activates Skeletal Muscle Thermogenesis and Protects Mice from High-Fat Diet Induced Metabolic Dysfunction

Salsalate plays beneficial roles for ameliorating hyperglycemia and dyslipidemia in type 2 diabetes patients, but the underlying mechanisms are still poorly understood. In this study, by administering salsalate to mice fed with high fat diet and examining how salsalate rectifies metabolic dysfunction in these obese mice, we found that salsalate stimulated body temperature and attenuated body weight gain without affecting food intake. Our results showed that salsalate application decreased lipid accumulation in liver and epididymal white adipose tissue (eWAT), inhibited hepatic gluconeogenesis and improved insulin signaling transduction in eWAT. In addition, salsalate increased the expression of genes related to glucose and fatty acid transport and oxidation in skeletal muscle. Our results also showed that expression of genes in mitochondrial uncoupling and mitochondrial electron transport are strengthened by salsalate. Moreover, sarcolipin (Sln) and sarcoplasmic reticulum Ca²⁺ ATPase 2 (Serca2) in skeletal muscle were enhanced in salsalate-treated mice. Together, our data suggest that the beneficial metabolic effects of salsalate may depend, at least in part, on skeletal muscle thermogenesis via activation of mitochondrial uncoupling and the axis of Sln/Serca2a.