title: Induction of CYP2B6 and CYP3A4 expression by 1-aminobenzotriazole (ABT) in human hepatocytes.
abstract: 1-Aminobenzotriazole (ABT) has been widely used in drug development process as an irreversible inhibitor of CYP enzymes. One potential use of ABT is to potentiate pharmacological effects of rapidly-metabolized drugs on CYP expression by inhibiting their metabolism; however, ABT's own effects on CYP expression have been unknown. In this study, we show that ABT up-regulates expression of CYP2B6 and CYP3A4 potentially by activating nuclear receptor CAR. In freshly isolated human hepatocytes, ABT increased mRNA expression of CYP2B6 and CYP3A4 in a concentration-dependent manner. ABT also modulated CYP-inducing actions of CITCO and rifampin, the known inducers of CYP2B6 and CYP3A4. Results from luciferase reporter assays confirmed that ABT increases CYP2B6 promoter activity in CAR-expressing HepG2 cells. These results suggest that the use of ABT as a potentiator of pharmacological effects of rapidly-metabolized drugs is limited due to its own pharmacological actions on CYP expression as a CAR activator.
authors.affiliation: Department of Pharmacy Practice, College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, IL 60612, USA.
authors.forename: Kyunghee
authors.initials: K
authors.lastname: Yang
authors.forename: Kwi Hye
authors.initials: KH
authors.lastname: Koh
authors.forename: Hyunyoung
authors.initials: H
authors.lastname: Jeong
mesh_terms: D001189:Aryl Hydrocarbon Hydroxylases / Q000096:biosynthesis* / Q000235:genetics; D000090702:Constitutive Androstane Receptor; D065702:Cytochrome P-450 CYP2B6; D051544:Cytochrome P-450 CYP3A / Q000096:biosynthesis* / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D010089:Oxidoreductases, N-Demethylating / Q000096:biosynthesis* / Q000235:genetics; D010091:Oximes / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis; D018160:Receptors, Cytoplasmic and Nuclear / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012293:Rifampin / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D015533:Transcriptional Activation / Q000187:drug effects; D014162:Transfection; D014230:Triazoles / Q000494:pharmacology*
chemical_list: D000090702:Constitutive Androstane Receptor; D010091:Oximes; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D013844:Thiazoles; D014230:Triazoles; C033020:1-aminobenzotriazole; C475093:6-(4-chlorophenyl)imidazo(2,1-b)(1,3)thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime; D001189:Aryl Hydrocarbon Hydroxylases; C585599:CYP2B6 protein, human; D065702:Cytochrome P-450 CYP2B6; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; D010089:Oxidoreductases, N-Demethylating; D012293:Rifampin