The present study was aimed to evaluate the anti-adipogenic activity of piperine (PIP) and epigallocatechin gallate (EGCG) in 3T3-L1 cells. In cytotoxicity studies, PIP and EGCG showed IC50 values of 260 and 218 µM respectively and in combination (20 µM each) did not show cytotoxicity. Treatment with PIP and EGCG (20 µM each) significantly (p<.01) inhibited cell differentiation, lipid droplets deposition and enhanced glycerol release in 3T3-L1 cells. The secreted level of leptin was decreased but adiponectin level was increased in treated 3T3-L1 cells than untreated cells. In molecular expression studies, key adipogenic genes PPAR-γ, SREBP-1c, FAS, Fab-4, C/EBP-α and HMG-CoA reductase were markedly down-regulated but UCP-1 was up-regulated intreated 3T3-L1 cells and the same trend was observed in expression levels of selected proteins. In conclusion, our results demonstrated a combination of PIP and EGCG exhibited strong anti-adipogenic and lipid lowering effect than individual treatments due to synergism.
Keywords: 3T3-L1 cells; adipogenesis; epigallocatechin gallate; lipolysis; piperine.