Abstract

Background Obesity is defined as an imbalance between energy intake and expenditure, and it is a serious risk factor of non-communicable diseases. Recently many studies have shown that promoting browning of white adipose tissue (WAT) to increase energy consumption has a great therapeutic potential for obesity. Sesamol, a lignan from sesame oil, had shown potential beneficial functions on obesity treatment. Objective In this study, we used C57BL/6J mice and 3T3-L1 adipocytes to investigate the effects and the fundamental mechanisms of sesamol in enhancing the browning of white adipocytes to ameliorate obesity. Methods Sixteen-week-old C57BL/6J male mice were fed high-fat diet (HFD) for 8 weeks to establish the obesity models. Half of the obese mice were administered with sesamol (100 mg/kg body weight [b.w.]/day [d] by gavage for another 8 weeks. Triacylglycerol (TG) and total cholesterol assay kits were used to quantify serum TG and total cholesterol (TC). Oil red O staining was used to detect lipid droplet in vitro . Mito-Tracker Green was used to detect the mitochondrial content. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the levels of beige-specific genes. Immunoblotting was used to detect the proteins involved in beige adipocytes formation. Results Sesamol decreased the content of body fat and suppressed lipid accumulation in HFD-induced obese mice. In addition, sesamol significantly upregulated uncoupling protein-1 (UCP1) protein in adipose tissue. Further research found that sesamol also significantly activated the browning program in mature 3T3-L1 adipocytes, manifested by the increase in beige-specific genes and proteins. Moreover, sesamol greatly increased mitochondrial biogenesis, as proved by the upregulated protein levels of mitochondrial biogenesis, and the inhibition of the proteins associated with mitophagy