To investigate the effects of berberine(BBR) and cinnamic acid(CA),the main active compounds of Jiaotai pills,and the combination of berberine and cinnamic acid(BBR/CA) on palmitic acid(PA)-induced lipid accumulation in NIT-1 pancreatic B cells.Methods:Cells were incubated in culture medium containing PA for 24 hours to establish a model of lipid accumulation induced by high fat.Then treatments with BBR,CA,the combination of BBR and CA(BBR/CA) and Metformin(Met) were performed respectively,and a control group was set up.Intracellular lipid accumulation was assessed by Oil Red O staining and TG content was measured by enzymatic assay.The expression of adenosine monophosphate-activated protein kinase(AMPK) protein and its downstream lipogenic and fatty acid oxidation genes,including fatty acid synthase(FAS),acetyl-CoA carboxylase(ACC),phosphorylation acetyl-CoA carboxylase(p-ACC),carnitine acyl transferase 1(CPT-1) and sterol regulatory element binding protein 1c(SREBP-1c) were determined by Western blot or real time polymerase chain reaction(RT-PCR).Results:PA induced an obvious lipid accumulation and a significant increase in intracellular TG content in NIT-1 pancreatic B cells.PA also induced a remarkable decrease in AMPK protein expression and its downstream targets such as p-ACC and CPT-1.Meanwhile,AMPK downstream lipogenic genes,including SREBP-1c mRNA,FAS and ACC protein expressions,were increased significantly.Treatments with BBR and BBR/CA,superior to CA,significantly reversed the above genes changes in NIT-1 pancreatic B cells.Conclusion:It can be concluded that in vitro,the active compounds of Jiaotai pills inhibits PA-induced lipid accumulation by decreasing lipogenesis and increasing lipid oxidation in NIT-1 pancreatic B cells.