Medium-chain triglyceride attenuates obesity by activating brown adipose tissue via upregulating the AMPK signaling pathway

Medium-chain triacylglycerol (MCT) is a healthy lipid mainly composed of medium-chain fatty acids (MCFA), which has been proven to have physiological activities in improving metabolic disorders, reducing blood cholesterol, and controlling weight. Brown adipose tissue (BAT) has been regarded as a potential organ to fight obesity due to the function of thermogenesis and energy dissipation. Previous reports found that a diet rich in MCT contributed to the activation of BAT. However, the potential mechanism between MCT and BAT remains unknown. In the current study, MCFA was applied on C3H/10T1/2 cells differentiated brown adipocytes, and MCT was applied on high-fat diet (HFD) induced obese mice. The results showed that MCFA and MCT induced browning of adipocytes and activation of BAT, significantly increased the enrichment of mitochondria, and significantly reduced intracellular lipid accumulation and body weights in vivo and in vitro. Mechanically, MCT significantly increased the level of UCP1, AMPK, and the downstream signaling factors of Pgc1α and Ulk1, further significantly elevated the brown differentiation factor of Pparγ. Moreover, The AMPK inhibitor dorsomorphin partially impaired the beneficial effects caused by MCT. In conclusion, this study proved that AMPK is the potential target of MCT to induce BAT activation and provided theoretical evidence for the application of MCT in the future.