title: Transcriptional Regulation of CYP3A4/2B6/2C9 Mediated via Nuclear Receptor PXR by Helicid and Its Metabolites.
abstract: Objective. This study aims at establishing and validating an in vitro system to screen drug inducers of CYPs mediated via hPXR, as well as studying transcriptional regulation of CYPs mediated via hPXR by helicid and its two metabolites. Methods. Cloning the nuclear receptor hPXR and the promoters of CYP3A4, CYP2B6, CYP2C9, and inserting the trans-element to the upstream of firefly luciferase reporter gene of the pGL4.17 vectors, then cotransfecting the report vectors and hPXR expression plasmid to HepG2 cell line. After 24 hours, the transfected cells were treated with helicid (0.004, 0.04, and 0.4 μmol/L) and its metabolite I and metabolite II (0.0004, 0.004, and 0.04 μmol/L) for 48 h, while rifampin (10 μmol/L) was included as the positive control and 0.1% DMSO as the negative control group. Cells were lysized and luciferase activity was determined using a dual luciferase reporter assay kit. Results. Helicid and its metabolites did not significantly increase promoter activities of CYP3A4, CYP2B6, and CYP2C9 in HepG2 cells transfected with PXR expression plasmid (P > 0.05). Conclusion. PXR-expressed CYP3A4, CYP2B6, and CYP2C9 dual luciferase reporter gene platforms were successfully established, and helicid and its metabolites I, II do not significantly induce the transcription of CYP3A4, CYP2B6, and CYP2C9.
authors.affiliation: Department of Clinical Pharmacy, Yijishan Hospital of Wannan Medical College, Anhui Provincial Center for Drug Clinical Evaluation, Wuhu, Anhui 241001, China ; Traditional Chinese Medical Hospital, Wuhu, Anhui 241001, China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Clinical Pharmacy, Yijishan Hospital of Wannan Medical College, Anhui Provincial Center for Drug Clinical Evaluation, Wuhu, Anhui 241001, China.
authors.forename: Hai-Tang
authors.initials: HT
authors.lastname: Xie
authors.affiliation: Department of Traditional Chinese Medicine, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui 241001, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410078, China ; Institute of Clinical Pharmacology, Central South University, Changsha 410078, China.
authors.forename: Guo
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Clinical Pharmacy, Yijishan Hospital of Wannan Medical College, Anhui Provincial Center for Drug Clinical Evaluation, Wuhu, Anhui 241001, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Clinical Pharmacy, Yijishan Hospital of Wannan Medical College, Anhui Provincial Center for Drug Clinical Evaluation, Wuhu, Anhui 241001, China.
authors.forename: Zhi-Chen
authors.initials: ZC
authors.lastname: Pu
authors.affiliation: Department of Clinical Pharmacy, Yijishan Hospital of Wannan Medical College, Anhui Provincial Center for Drug Clinical Evaluation, Wuhu, Anhui 241001, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Hu