A natural small molecule pinocembrin resists high-fat diet-induced obesity through GPR120-ERK1/2 pathway

Abstract

Obesity is a widely concerned health problem. Mobilizing white adipose tissue and reducing fat synthesis are considered as effective strategies in the treatment of obesity. Here, using Connectivity Map (CMap) approach, we identified the pinocembrin (PB), a natural flavonoid primarily found in propolis, as a potential anti-obesity drug. Therefore, high-fat-diet (HFD) mice were randomly divided into two groups and fed a HFD or HFD with PB in this study. In vivo experiments showed that supplementation of PB reduced the body weight gain and ameliorated insulin resistance in HFD-induced mice. More importantly, PB did not cause side effect through detecting the levels of alanine transaminase (ALT), aspartate aminotransferase (AST), creatinine (CRE) and blood urea nitrogen (BUN) in serum of mice. Additionally, PB reduced expansion of white adipose tissue with upregulation of genes related lipolysis and downregulation of genes related lipogenesis. Furthermore, in vitro experiments revealed that PB treatment dose-dependently inhibited lipid droplet formation with upregulation of genes related lipolysis and downregulation of genes related lipogenesis. Molecular docking analysis combined with cellular thermal shift assay (CETSA) suggested that PB has a high affinity to the G protein-coupled receptor 120 (GPR120). Meanwhile, we confirmed that PB efficiently inhibited adipogenic differentiation of preadipocytes by directly binding to GPR120 and subsequently activating the downstream phosphorylation extracellular regulated kinase 1/2 (ERK1/2). Collectively, PB exerted anti-obesity effect through GPR120-ERK1/2 signaling pathway, providing a novel and promising natural drug for the treatment of obesity.