Natural Bioactive Compounds Targeting FABP4 in Adipogenesis and Obesity: Evidence from In Vitro and In Vivo Studies

FABP4 (fatty acid-binding protein 4) is a lipid chaperone and secreted adipokine linking dysregulated fatty acid handling with inflammation, cellular stress, and insulin resistance in obesity. By modulating nuclear receptor signaling (notably PPARγ) and enhancing NF-κB/MAPK activation in adipocytes and macrophages, FABP4 contributes to maladaptive adipose remodeling and systemic metabolic decline. This review critically summarizes recent preclinical evidence on natural bioactive compounds that regulate FABP4 expression and associated adipogenic programs in models of adipogenesis and diet-induced obesity. Data from 3T3-L1/OP9 adipocytes, rodent studies, and selected alternative models indicate that many plant-derived extracts and phytochemicals (e.g., polyphenols, saponins, coumarins, terpenoids, and fermented products) down-regulate FABP4 at mRNA and/or protein levels. These effects are frequently accompanied by suppression of PPARγ/C/EBPα/SREBP1c signaling, activation of AMPK-related pathways, reduced lipid accumulation, and improved metabolic outcomes including lower weight gain, reduced adipocyte hypertrophy, improved steatosis, and favorable serum lipid profiles. Natural compounds from non-plant sources (animal- and microbe-derived metabolites) further broaden FABP4-targeting strategies, supporting FABP4 as a cross-class therapeutic node. Key translational barriers include poor extract standardization, incomplete identification of active constituents, limited oral bioavailability, microbiome-dependent variability, and scarce clinical validation. Future work should prioritize well-characterized lead scaffolds, targeted delivery, rational combinations, and standardized, adequately powered clinical trials assessing dose, durability of FABP4 suppression, and cardiometabolic safety.