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Identification of cytochrome P450 enzymes responsible for metabolism of cannabidiol by human liver microsomes.

Abstract

AIMS

Cannabidiol (CBD), one of the major constituents in marijuana, has been shown to be extensively metabolized by experimental animals and humans. However, human hepatic enzymes responsible for the CBD metabolism remain to be elucidated. In this study, we examined in vitro metabolism of CBD with human liver microsomes (HLMs) to clarify cytochrome P450 (CYP) isoforms involved in the CBD oxidations.

MAIN METHODS

Oxidations of CBD in HLMs and recombinant human CYP enzymes were analyzed by gas chromatography/mass spectrometry.

KEY FINDINGS

CBD was metabolized by pooled HLMs to eight monohydroxylated metabolites (6α-OH-, 6β-OH-, 7-OH-, 1″-OH-, 2″-OH-, 3″-OH-, 4″-OH-, and 5″-OH-CBDs). Among these metabolites, 6α-OH-, 6β-OH-, 7-OH-, and 4″-OH-CBDs were the major ones as estimated from the relative abundance of m/z 478, which was a predominant fragment ion of trimethylsilyl derivatives of the metabolites. Seven of 14 recombinant human CYP enzymes examined (CYP1A1, CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5) were capable of metabolizing CBD. The correlations between CYP isoform-specific activities and CBD oxidative activities in 16 individual HLMs indicated that 6β-OH- and 4″-OH-CBDs were mainly formed by CYP3A4, which was supported by inhibition studies using ketoconazole and an anti-CYP3A4 antibody. The correlation and inhibition studies also showed that CBD 6α-hydroxylation was mainly catalyzed by CYP3A4 and CYP2C19, whereas CBD 7-hydroxylation was predominantly catalyzed by CYP2C19.

SIGNIFICANCE

This study indicated that CBD was extensively metabolized by HLMs. These results suggest that CYP3A4 and CYP2C19 may be major isoforms responsible for 6α-, 6β-, 7-, and/or 4″-hydroxylations of CBD in HLMs.

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  • Publisher Full Text
  • Authors+Show Affiliations

    ,

    Department of Hygienic Chemistry, Hokuriku University, Ho-3 Kanagawa-machi, Kanazawa, Japan.

    , , ,

    Source

    Life sciences 89:5-6 2011 Aug 1 pg 165-70

    MeSH

    Antibodies, Blocking
    Antibodies, Monoclonal
    Aryl Hydrocarbon Hydroxylases
    Biotransformation
    Cannabidiol
    Chromatography, Gas
    Cytochrome P-450 CYP2C19
    Cytochrome P-450 CYP3A
    Cytochrome P-450 CYP3A Inhibitors
    Cytochrome P-450 Enzyme Inhibitors
    Cytochrome P-450 Enzyme System
    Enzyme Inhibitors
    Humans
    Hydroxylation
    In Vitro Techniques
    Isoenzymes
    Microsomes, Liver
    Oxidation-Reduction
    Phenotype
    Recombinant Proteins

    Pub Type(s)

    Journal Article
    Research Support, Non-U.S. Gov't

    Language

    eng

    PubMed ID

    21704641

    Citation

    TY - JOUR T1 - Identification of cytochrome P450 enzymes responsible for metabolism of cannabidiol by human liver microsomes. AU - Jiang,Rongrong, AU - Yamaori,Satoshi, AU - Takeda,Shuso, AU - Yamamoto,Ikuo, AU - Watanabe,Kazuhito, Y1 - 2011/06/16/ PY - 2010/12/9/received PY - 2011/4/28/revised PY - 2011/5/12/accepted PY - 2011/6/16/aheadofprint PY - 2011/6/28/entrez PY - 2011/6/28/pubmed PY - 2011/9/13/medline SP - 165 EP - 70 JF - Life sciences JO - Life Sci. VL - 89 IS - 5-6 N2 - AIMS: Cannabidiol (CBD), one of the major constituents in marijuana, has been shown to be extensively metabolized by experimental animals and humans. However, human hepatic enzymes responsible for the CBD metabolism remain to be elucidated. In this study, we examined in vitro metabolism of CBD with human liver microsomes (HLMs) to clarify cytochrome P450 (CYP) isoforms involved in the CBD oxidations. MAIN METHODS: Oxidations of CBD in HLMs and recombinant human CYP enzymes were analyzed by gas chromatography/mass spectrometry. KEY FINDINGS: CBD was metabolized by pooled HLMs to eight monohydroxylated metabolites (6α-OH-, 6β-OH-, 7-OH-, 1″-OH-, 2″-OH-, 3″-OH-, 4″-OH-, and 5″-OH-CBDs). Among these metabolites, 6α-OH-, 6β-OH-, 7-OH-, and 4″-OH-CBDs were the major ones as estimated from the relative abundance of m/z 478, which was a predominant fragment ion of trimethylsilyl derivatives of the metabolites. Seven of 14 recombinant human CYP enzymes examined (CYP1A1, CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5) were capable of metabolizing CBD. The correlations between CYP isoform-specific activities and CBD oxidative activities in 16 individual HLMs indicated that 6β-OH- and 4″-OH-CBDs were mainly formed by CYP3A4, which was supported by inhibition studies using ketoconazole and an anti-CYP3A4 antibody. The correlation and inhibition studies also showed that CBD 6α-hydroxylation was mainly catalyzed by CYP3A4 and CYP2C19, whereas CBD 7-hydroxylation was predominantly catalyzed by CYP2C19. SIGNIFICANCE: This study indicated that CBD was extensively metabolized by HLMs. These results suggest that CYP3A4 and CYP2C19 may be major isoforms responsible for 6α-, 6β-, 7-, and/or 4″-hydroxylations of CBD in HLMs. SN - 1879-0631 UR - https://www.unboundmedicine.com/medline/citation/21704641/abstract/Identification_of_cytochrome_P450_enzymes_responsible_for_metabolism_of_cannabidiol_by_human_liver_microsomes_ L2 - http://linkinghub.elsevier.com/retrieve/pii/S0024-3205(11)00264-5 ER -