Natural bioactive constituents from herbs and nutraceuticals promote browning of white adipose tissue

Obesity is a significant public health problem worldwide that is characterized by abnormal or excessive fat accumulation. Unfortunately, the application of available weight-loss drugs has been restricted because of their serious adverse effects. Browning of white adipose tissue (WAT), which refers to the transformation of white adipocytes to beige adipocytes under certain stimulations, is regarded as a new strategy to solve the obesity problem. Numerous studies have recently evidenced that traditional Chinese medicine (TCM) could promote browning of WAT with multi-component and multi-target characteristics. This article summarizes natural constituents from TCM with stimulatory effects on browning of WAT in the past two decades. The active ingredients can be generally divided into polyphenols, saponins, alkaloids, terpenoids, phenylpropanoids and others, such as resveratrol, quercetin, curcumin, genistein, capsaicin, epigallocatechin gallate (EGCG), berberine, menthol, emodin and ginsenosides. Simultaneously, the chemical structures, source, model, efficacy and mechanism of these monomeric compounds are also described. And the mechanisms of these active ingredients are mainly involved in the regulation of PRDM16, PGC-1α, PPARγ, SIRT1, AMPK, β3-adrenergic receptors, TRPV1 and TRPM8 channels, FGF21 and miRNAs. The present article opens opportunities for developing novel drugs or supplements from TCM with wide acceptability to prevent obesity progression and its associated metabolic disorders.