Effects of berberine and cinnamic acid on palmitic acid-induced intracellular triglyceride accumulation in NIT-1 pancreatic β cells.
OBJECTIVE
To investigate the effects of berberine (BBR) and cinnamic acid (CA), the main active components in Jiaotai Pill (, JTP), on palmitic acid (PA)-induced intracellular triglyceride (TG) accumulation in NIT-1 pancreatic β cells.


METHODS
Cells were incubated in culture medium containing PA (0.25 mmol/L) for 24 h. Then treatments with BBR (10 μmol/L), CA (100 μmol/L) and the combination of BBR and CA (BBR+CA) were performed respectively. Intracellular lipid accumulation was assessed by Oil Red O staining and TG content was measured by colorimetric 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 (pACC), carnitine acyl transferase 1 (CPT-1) and sterol regulating element binding protein 1c (SREBP-1c) were determined by Western blot or real time polymerase chain reaction.


RESULTS
PA induced an obvious lipid accumulation and a significant increase in intracellular TG content in NIT-1 cells. PA also induced a remarkable decrease in AMPK protein expression and its downstream targets such as pACC and CPT-1. Meanwhile, AMPK downstream lipogenic genes including SREBP-1c mRNA, FAS and ACC protein expressions were increased. Treatments with BBR and BBR+CA, superior to CA, significantly reversed the above genes changes in NIT-1 pancreatic β cells. However, the synergistic effect of BBR and CA on intracellular TG content was not observed in the present study.


CONCLUSION
It can be concluded that in vitro, BBR and BBR+CA could inhibit PA-induced lipid accumulation by decreasing lipogenesis and increasing lipid oxidation in NIT-1 pancreatic β cells.
['Zhao|Li|L|', 'Jiang|Shu-Jun|SJ|', 'Lu|Fu-Er|FE|', 'Xu|Li-Jun|LJ|', 'Zou|Xin|X|', 'Wang|Kai-Fu|KF|', 'Dong|Hui|H|']
D055372:AMP-Activated Protein Kinases D000818:Animals D001599:Berberine D002460:Cell Line D002934:Cinnamates D005227:Fatty Acids D005786:Gene Expression Regulation D050417:Insulin-Secreting Cells D042541:Intracellular Space D050155:Lipogenesis D051379:Mice D010084:Oxidation-Reduction D019308:Palmitic Acid D014280:Triglycerides
berberine cinnamic acid Jiaotai Pill palmitic acid lipid NIT-1 cells Chinese medicine