Potential of Natural Products in the Inhibition of Adipogenesis through Regulation of PPARγ Expression and/or Its Transcriptional Activity

Obesity is a global health problem characterized as an increase in the mass of adipose tissue. Adipogenesis is one of the key pathways that increases the mass of adipose tissue, by which preadipocytes mature into adipocytes through cell differentiation. Peroxisome proliferator-activated receptor gamma (PPAR gamma), the chief regulator of adipogenesis, has been acutely investigated as a molecular target for natural products in the development of anti-obesity treatments. In this review, the regulation of PPAR gamma expression by natural products through inhibition of CCAAT/enhancer-binding protein beta (C/EBP beta) and the farnesoid X receptor (FXR), increased expression of GATA-2 and GATA-3 and activation of the Wnt/beta-catenin pathway were analyzed. Furthermore, the regulation of PPAR gamma transcriptional activity associated with natural products through the antagonism of PPAR gamma and activation of Sirtuin 1 (Sirt1) and AMP-activated protein kinase (AMPK) were discussed. Lastly, regulation of mitogen-activated protein kinase (MAPK) by natural products, which might regulate both PPAR gamma expression and PPAR gamma transcriptional activity, was summarized. Understanding the role natural products play, as well as the mechanisms behind their regulation of PPAR gamma activity is critical for future research into their therapeutic potential for fighting obesity.