Natural Product Ligands of the Peroxisome Proliferator-Activated Receptor Gamma as Anti-Inflammatory Mediators

Immunologists have long considered inflammation to be a two-edged sword. Short-term inflammation can be beneficial, but long-term chronic inflammation is damaging. Obesity, type 2 diabetes (T2D), and cancer have recently been added to the never-ending list of inflammatory diseases. The nuclear transcription factor peroxisome proliferator-activated receptor gamma (PPAR-γ) is involved in inflammation and obesity. Clinicians employed PPAR-γ agonists, both synthetic and natural, to treat disorders such as obesity and T2D without fully understanding the biochemical features and potential adverse effects. This is one of the reasons for the controversy surrounding the thiazolidinedione class of medicines, including rosiglitazone and pioglitazone. Nonetheless, various natural PPAR-γ ligands, including endogenous physiological ligands, are discovered regularly around the world. This review aims to summarise the physiochemical properties and possible antiinflammatory actions of ligands discovered in nature. Future research in this area should be supported in order to find improved commercial PPAR-γ ligand anti-inflammatory products.