Inhibition of palmitic acid induced adipogenesis by natural polyphenols in 3T3-L1 adipocytes.

Dietary free fatty acids induce preadipocyte differentiation in the presence of a hormonal cocktail in 3T3-L1 adipocytes. Plant polyphenols are curb adipocyte differentiation and protect from metabolic stress. In the present study, we examined the effects of the saturated fatty acid, palmitic acid (PA) in presence of flavonoids, chrysin (CR) and hesperidin (HD) and phenolic acid, syringic acid (SYA) and sinapic acid (SIA). Adipocytes were incubated for 10 d with 100 μmol of PA along with 10-100 µmol CR/HD and 100-1000 µmol SYA/SIA. PA induced clonal expansion of preadipocytes, differentiation and oxidative stress in 3T3-L1 cells following 10 d of differentiation. Adipocytes treated with PA exhibited an increase of 300% in clonal population, 110% lipid and 172% reactive oxygen species accumulation. But treatment with CR, HD, SYA and SIA in the presence of PA concentration-dependent effect was observed. Concentrations of CR/HD and SYA/SIA inhibited PA-induced mRNA expression of PPARγ, C/EBPα, SREBP-1c, FAS and NOX4. Moreover, CR, HD, SYA and SIA did not exhibit toxicity in Drosophila DNA. In summary, these results suggest that dietary fatty acids act directly on adipocytes and addition of CR, HD, SYA and SIA resulted in reduction of PA-induced negative effects on 3T3-L1 adipocytes. HIGHLIGHTS: • Palmitic acid, the common dietary free fatty acid, is known to induce adipogenesis in 3T3-L1 adipocytes. • Treatment of differentiating adipocytes with flavonoids and phenolic acids reduced palmitic acid-induced clonal expansion of preadipocytes. • Phytocompounds reduced lipid accumulation and triglyceride production as well as ROS accumulation. • Thus, the phytocompounds showed effective anti-adipogenic activity even in palmitic acid challenged environment in adipocytes.