6种中药单体对人孕烷X受体介导细胞色素酶P450 3A4转录的调节作用

Transcriptional regulation of cytochrome P450 3A4 through human pregnane X receptor by six monomers of Traditional Chinese Medicine

目的研究6种中药单体野黄芩苷、丹皮酚、芍药苷、甘草苷、黄芪甲苷以及黄芩素是否可以通过诱导孕烷X受体(PXR)介导细胞色素酶P4503A4(CYP3A4)转录表达。方法采用脂质体瞬时转染的方法,将人PXR表达质粒、CYP3A4报告质粒以及内参质粒转入LS174T细胞中,建立报告基因体系,与不同浓度及不同给药时间的中药单体共同孵育,检测细胞中荧光素酶的活性。结果黄芩素(20μmol/L、40μmol/L和80μmol/L)分别诱导PXR介导CYP3A4表达(1.49±0.23)倍(P<0.05)、(2.45±0.56)倍(P<0.01)和(5.27±0.40)倍(P<0.01),野黄芩苷、丹皮酚、芍药苷、甘草苷和黄芪甲苷在实验的浓度范围内不能明显诱导LS174T细胞中PXR介导CYP3A4表达。在不同给药时间实验中,20μmol/L、40μmol/L和80μmol/L的黄芩素在12～48h能诱导PXR介导CYP3A4表达,诱导能力随时间的延长而呈增强的趋势,各浓度的最大诱导倍数均在48h出现。结论黄芩素在LS174T细胞系中可以通过诱导PXR介导CYP3A4转录表达,而野黄芩苷、丹皮酚、芍药苷、甘草苷或黄芪甲苷无此作用。

Objective To examine the effects of scutellarin,paeonol,paeoniflorin,liquiritin,astragaloside Ⅳ and baicalein on the human PXR mediated transcriptional regulation of CYP3A4. Method Transient cotransfection reporter gene assay was performed on LS174T cells using the PXR expression plasmid and the CYP3A4-luciferase reporter plasmid. Results Only baicalein was found to dose-dependently induce the CYP3A4 transcription in LS174T cells. At the concentrations of 20 μmol/L, 40 μmol/L and 80 μmol/L, there was a（1.49±0.23） fold （P0.05）,（2.45±0.56）fold （P0.01） and （5.27±0.40） fold （P0.01） increased in baicalein-treated cells. In the time course study, baicalein time-dependently （12-48 h） induced CYP3A4 transcription,and the induction reached a maximum level at 48 h. Conclusion Baicalein can induce the CYP3A4 transcription through PXR in LS174T cells.