4种中药调节细胞色素P4503A4转录表达的研究

Transcriptional regulation of cytochrome P450 3A4 by four kinds of traditional Chinese medicines

目的:从中药中筛选通过激活人孕烷X受体(PXR)诱导细胞色素P450 3A4(CYP3A4)转录表达的中药;研究其诱导能力与药物浓度和作用时间之间的关系。方法:在HepG2细胞中,采用瞬时共转染报告基因试验筛选对CYP3A4转录表达有诱导作用的中药,研究其在不同浓度和不同作用时间下对PXR介导的CYP3A4的转录调节作用。结果:中药莪术、苍术、白术和茯苓均能通过激活PXR诱导CYP3A4的转录表达,且具有浓度-效应关系和时间-效应关系。在浓度-效应关系中,500 mg.L-1的莪术、苍术、白术和茯苓,在作用时间24 h时,其诱导倍数分别为0.1%DMSO处理细胞的(6.82±0.09),(6.76±0.20),(5.49±0.13),(4.97±0.07)倍。在时间-效应关系研究中,500 mg.L-1的莪术、苍术、白术和茯苓,在作用时间为48 h时,其诱导倍数分别为0.1%DMSO作用细胞的(7.74±0.54),(7.34±0.10),(5.54±0.11),(5.32±0.18)倍。结论:中药莪术、苍术、白术和茯苓均能够通过激活PXR诱导CYP3A4的转录表达。

Objective： To screen a group of traditional Chinese medicines with effect on pregnane X receptor （PXR） -mediated transcription regulation of P450 3A4 （CYP3A4） ; and to study whether they can induce the expression of CYP3A4 with a dose, timedependent manner. Method： Transient cotransfection reporter gene assays were performed with pCI-hPXR-neo, pGL3-CYP3A4-Luc and β-galactosidase expression plasmid in HepG2 cells. Result： Rhizoma Curcumae, Atractylodes lancea, A. macrocaphala and Poria cocos could induce transcriptional expression of CYP3A4. In the dose-effect study, 24 h after induction, 500 mg · L^-1 Rhizoma Curcumae, A. lancea, A. macrocaphala and Poria cocos, respectively, could induce the CYP3A4 gene expression with （6. 82 ±0. 09）, （6. 76 ±0. 20）, （5.49 ±0. 13） and （4. 97 ±0. 07） folds, as compared with 0. 1% DMSO treatedcells. In the time-effect study, 500 mg · L^-1 Rhizoma curcumae, A. lancea, A. macrocaphala and Poria cocos for 48 h could induce the CYP3A4 gene expression with （7.74 ±0. 54）, （7.34 ±0. 10）, （5.54±0. 11 ） and （5.32±0. 18） folds, compared with 0. 1% DMSO treated cells. Conclusion： Rhizoma Curcumae, A. lancea, A. macrocaphala and Poria cocos could induce the expression of CYP3A4 gene transcription through activating PXR.