title: CAR-mediated up-regulation of CYP3A4 expression in LS174T cells by Chinese herbal compounds.
abstract: The constitutive androstane receptor (CAR) is an orphan nuclear receptor which has been shown to participate in the activation of human CYP3A4, which metabolizes more than 50% of clinically used drugs. We investigated the effects of an array of compounds isolated from herbal medicines such as Rheum palmatum (Da Huang), Peucedanum praeruptorum Dunn (Qian Hu), Cortex Mori Radicis (Sang Bai Pi), Radix Asteris (Zi Wan), Salvia miltiorrhiza (Dan Shen), Polygonum cuspidatum Sieb. et Zucc (Hu Zhang), and Ginkgo biloba (Yin Xing) on the CAR-mediated transactivation of CYP3A4. The effect of herbal compounds on CYP3A4 expression was measured using a CYP3A4 luciferase reporter gene assay in transiently transfected human intestinal LS174T cells. The gene expression, protein expression, and catalytic activity of CYP3A4 in LS174T cells transfected with CAR were determined by using real-time PCR, Western blot analysis, and LC-MS/MS-based substrate assay. The study found that in CAR-transfected cells, praeruptorin A, C, and D significantly induced CYP3A4 luciferase activity, mRNA expression, and functional activity through the CAR-mediated pathway; conversely, induction was not found in untransfected cells. Our findings suggest that these herbal compounds can significantly up-regulate the CYP3A4 gene via the CAR-mediated pathway, which has important implications in herb-drug interactions.
authors.affiliation: Laboratory of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Huang
authors.forename: Hui-Chang
authors.initials: HC
authors.lastname: Bi
authors.forename: Ya-He
authors.initials: YH
authors.lastname: Liu
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Wang
authors.forename: Xin-Ping
authors.initials: XP
authors.lastname: Xue
authors.forename: Min
authors.initials: M
authors.lastname: Huang
mesh_terms: D002121:Calcium Channel Blockers / Q000032:analysis / Q000378:metabolism; D045744:Cell Line, Tumor; D000090702:Constitutive Androstane Receptor; D003374:Coumarins / Q000378:metabolism*; D051544:Cytochrome P-450 CYP3A / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D004790:Enzyme Induction; D015870:Gene Expression / Q000187:drug effects; D017930:Genes, Reporter; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D009543:Nifedipine / Q000378:metabolism; D010957:Plasmids; D012313:RNA / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection; D015854:Up-Regulation
chemical_list: D002121:Calcium Channel Blockers; D000090702:Constitutive Androstane Receptor; D003374:Coumarins; D004365:Drugs, Chinese Herbal; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; C441070:praeruptorin A; D012313:RNA; D008156:Luciferases; D051544:Cytochrome P-450 CYP3A; D009543:Nifedipine