胡椒碱对脂多糖和金黄色葡萄球菌抑制人结肠腺癌细胞系表达防御素的拮抗作用

Piperine counteracts the inhibitory effect of lipopolysaccharide and staphylococcus aureus cells on the expression of defensins by human colon carcinoma HT-29 and Caco-2 cells

目的:研究胡椒碱(piperine,PIP)对脂多糖(LPS)和灭活金黄色葡萄球菌(SAC)菌体抑制人结肠腺癌HT-29和Caco-2细胞表达防御素(Defensin)的影响.方法:WST-1法检测PIP对HT-29和Caco-2细胞增殖的作用;定量PCR(qRT-PCR)检测人α防御素DEFA5(HD5)和DEFA6(HD6),人β防御素HBD-1以及胰岛再生源蛋白(Reg)Reg IIIγ等mRNA的表达水平.结果:PIP处理可剂量依赖性地抑制HT-29和Caco-2细胞的增殖,半数抑制浓度IC50分别为328.5μmol/L和155.1μmol/L,表明PIP对细胞的毒性较小;定量PCR检测显示,PIP处理对LPS或SAC下调HT-29和Caco-2细胞DEFA5和DEFA6 mRNA表达水平具有显著的拮抗作用,对DEFB1和Reg IIIγmRNA的表达没有明显影响.结论:胡椒碱可能通过拮抗病原体诱导细胞表达防御素的抑制作用,进而发挥其抗肠炎作用.

Aim：To explore the effect of piperine on the down-regulation of human defensins caused by lipopolysaccharide （LPS）and Staphylococcus aureus cells （SAC）stimulation in HT-29 and Caco-2 cells.Methods：The effect of piperine on cell proliferation was measured by WST-1 assay.The mRNA levels of human defensins （DEFA5,DEFA6 and DEFB1）and regenerating islet-derived protein （Reg） were detected by quantitative real-time RT-PCR.Results：Piperine could inhibit the proliferation of HT-29 and Caco-2 cells in a dose-dependent manner with their IC50 values of 328.5 μmol /L and 155.1μmol /L,respectively,demonstrating that the cytotoxicity of piperine was relatively low.RT-PCR showed＆nbsp;that LPS and SAC greatly suppressed the expression of human defensins DEFA5 and DEFA6 in HT-29 cells and Caco-2 cells while piperine significantly counteracted the inhibitory effect of LPS and SAC on the expression of DEFA5 and DEFA6 mRNAs,instead of DEFB1 and Reg IIIγmRNA.Conclusion：Pip-erine might exert its anti-colitis effect through antagonizing the inhibitory effect of LPS and SAC on the ex-pression of defensins in human intestinal epithelial cells.