Large yellow tea polysaccharides ameliorate obesity-associated metabolic syndrome by promoting M2 polarization of adipose tissue macrophages.

Obesity-induced metabolic syndrome is strongly associated with infiltrated adipose tissue macrophages (ATMs). Large yellow tea, a traditional functional beverage in China, has been shown to possess anti-obesity effects. However, the effect of large yellow tea polysaccharides (LYPs) against obesity-associated metabolic syndrome and their underlying mechanisms remain unclear and must be extensively investigated. In this study, we investigated the ameliorative effect of LYPs on metabolic syndrome using a high-fat diet (HFD)-induced obese mouse model. Our results indicated that LYPs significantly alleviated weight gain, dyslipidemia, glucose intolerance, and insulin resistance. Moreover, LYPs restored the homeostasis of energy metabolism and pancreatic ß-cell function. Notably, LYPs promoted M2 polarization of ATMs by regulating the expression of genes and specific cytokines involved in the assembly and secretion of M2 polarization. The improved metabolic syndrome of LYPs might be associated with the modulation of macrophage polarization. These findings suggest that LYPs might be a novel potential therapeutic agent to prevent or treat HFD-induced metabolic disorders by regulating M2 polarization.