| 【Objective】To compare the effect of berberine (BBR), cinnamic acid (CA), berberine andcinnamic acid (BBR/CA), which are contained in Jiaotaiwan, on lipid accumulation inNIT-1pancreatic β cells and to explore the related molecular mechanism.【Methods】To establish the intracellular lipid accumulation model induced by high glucose andhigh free fatty acid, NIT-1cells were incubated in culture medium containing25mmol/Lglucose or0.25mmol/L palmitic acid (PA) for24hours. Cells were divided into modelgroup, BBR (10μmol/L) group, CA (100μmol/L) group, BBR/CA (10μmol/L BBR and100μmol/L CA) group and metformin (35μmol/L Met) group. The correspondingintervention was administered. Meanwhile, a control group was set up. Intracellular lipidaccumulation was observed by oil red O staining method. Intracellular triglyceride (TG)content was examined by enzyme method. Western blot was used to determine the proteinexpressions of AMP activated protein kinase (AMPK), fatty acid synthase (FAS),acetyl-coA carboxylase (ACC), phosphorylation acetyl-coA carboxylase (P-ACC) andcarnitine acyl transferase1(CPT-1). Real time PCR (RT-PCR) was used to determine theexpression of sterol regulating element binding protein1c (SREBP-1c) mRNA.【Results】Compared with control group, intracellular TG content was significantly increased inmodel group (P<0.01). Compared with model group, intracellular TG content in BBR andBBR/CA groups were decreased remarkably (P<0.01) while that in CA group was notchanged in PA indueced NIT-1cells. Compared with BBR/CA group group, intracellularTG content in CA group was significantly increased (P<0.05). Compared with control group, the protein expressions of AMPK and P-ACC were obviously reduced while FAS,ACC and CPT-1protein expressions were elevated in model group (P<0.05, P<0.01).Compared with model group, the protein expressions of AMPK, P-ACC and CPT-1wereincreased while FAS and ACC protein expressions were decreased in BBR, CA andBBR/CA groups (P<0.05, P<0.01). Compared with BBR/CA group, P-ACC proteinexpression was increased (P<0.05) while the protein expressions of AMPK, FAS, ACC,CPT-1were not changed in BBR group, and the protein expressions of AMPK, FAS,P-ACC were decreased significantly (P<0.01, P<0.05) while ACC and CPT-1proteinexpressions were not changed in CA group. Compared with control group, the expressionof SREBP-1c mRNA was significantly increased in model group (P<0.01). Compared withmodel group, the expressions of SREBP-1c mRNA in BBR, CA and BBR/CA groups wereall reduced (P<0.01, P<0.05). Compared with BBR/CA group, the expressions ofSREBP-1c mRNA in BBR and CA groups were decreased obviously (P<0.01).【Conclusion】The active components in Jiaotaiwan may reduce intracellular lipid accumulation inNIT-1pancreatic β cells. The mechanism is possibly related to the activation of AMPK, thedecrease of lipogenesis and the increase of lipid oxidation. |
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