title: Identification of human cytochrome P450 enzymes involved in the metabolism of a novel к-opioid receptor agonist, nalfurafine hydrochloride.
abstract: Nalfurafine hydrochloride (TRK-820) exhibits strong к-opioid agonistic activity and is a new antipruritic agent for uremic pruritus. This study was performed to identify the human hepatic cytochrome P450 isoforms involved in the metabolic conversion of nalfurafine to the decyclopropylmethylated form, de-CPM, using human liver microsomes and E. coli membrane fractions expressing human P450 isoforms. Samples were analysed by liquid chromatography with a radioactivity detector and liquid chromatography-tandem mass spectrometry. The metabolism of nalfurafine by human liver microsomes exhibited a biphasic kinetic profile. Experiments examining the metabolism by E. coli membrane fractions expressing human P450 isoforms indicated that CYP1A1, 2C8, 2C19 and 3A4 had the ability to produce de-CPM. In experiments with human liver microsomes that examined the inhibition of nalfurafine metabolism by anti-human P450 antibodies, anti-CYP3A4 antibody predominantly, and anti-CYP2C8 and 2C19 antibodies moderately, inhibited de-CPM formation. From these results, CYP3A4 appeared to be the major isoform involved in the metabolic decyclopropylmethylation of nalfurafine, while CYP2C8 and 2C19 most likely play a minor role in the formation of de-CPM.
authors.affiliation: Toxicology and Pharmacokinetics Laboratories, Toray Industries, Inc., Japan. Akihiro_Ando@nts.toray.co.jp
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ando
authors.forename: Keiyu
authors.initials: K
authors.lastname: Oshida
authors.forename: Shinichi
authors.initials: S
authors.lastname: Fukuyama
authors.forename: Ayano
authors.initials: A
authors.lastname: Watanabe
authors.forename: Hisashi
authors.initials: H
authors.lastname: Hashimoto
authors.forename: Yohei
authors.initials: Y
authors.lastname: Miyamoto
mesh_terms: D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics / Q000378:metabolism; D001711:Biotransformation; D002462:Cell Membrane / Q000201:enzymology / Q000235:genetics; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics / Q000378:metabolism; D065731:Cytochrome P-450 CYP2C19; D065727:Cytochrome P-450 CYP2C8; D051544:Cytochrome P-450 CYP3A / Q000235:genetics / Q000378:metabolism; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D008745:Methylation; D008862:Microsomes, Liver / Q000187:drug effects* / Q000201:enzymology; D015394:Molecular Structure; D009019:Morphinans / Q000378:metabolism* / Q000493:pharmacokinetics; D017473:Receptors, Opioid, kappa / Q000819:agonists*; D013141:Spiro Compounds / Q000378:metabolism* / Q000493:pharmacokinetics
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D009019:Morphinans; D017473:Receptors, Opioid, kappa; D013141:Spiro Compounds; C111212:TRK 820; D003577:Cytochrome P-450 Enzyme System; D001189:Aryl Hydrocarbon Hydroxylases; C569463:CYP1A1 protein, human; C045793:CYP2C19 protein, human; C450259:CYP2C8 protein, human; D019363:Cytochrome P-450 CYP1A1; D065731:Cytochrome P-450 CYP2C19; D065727:Cytochrome P-450 CYP2C8; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human