Inhibition of human cytochrome P450 1B1, 1A1 and 1A2 by antigenotoxic compounds, purpurin and alizarin

Eizo Takahashi, Ken Ichi Fujita, Tetsuya Kamataki, Sakae Arimoto, Keinosuke Okamoto, Tomoe Negishi

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

Recently we have shown that anthraquinone food pigments such as purpurin and alizarin suppress the genotoxic activities of several mutagens including heterocyclic amines and polycyclic aromatic hydrocarbons in the Drosophila DNA repair test and in the Ames test. To investigate the mechanism of this inhibition, we have now examined the effects of these anthraquinone pigments on enzymes that metabolize xenobiotics. The activities of eight human recombinant cytochrome P450 (CYP) isozymes were measured in the presence of purpurin, alizarin or carminic acid. Purpurin and alizarin strongly inhibited the activities of CYP1A1, CYP1A2 and CYP1B1, and weakly suppressed those of CYP2A6 and CYP2E1 in a dose-dependent manner, but did not inhibit those of CYP2C19, CYP3A4 and CYP3A5. Carminic acid did not affect the activities of any CYPs tested. CYP1B1 was the most strongly affected CYP molecule by purpurin and alizarin among CYPs examined in this study. From kinetic analysis, it was shown that the inhibition by purpurin on CYP1B1 was both competitive and non-competitive, and that by alizarin was competitive. The values of slopes obtained from Lineweaver-Burk plots are proportional to the square of purpurin concentration. This observation suggests that two molecules of purpurin are interacting with one molecule of CYP1B1. The Km value of CYP1B1 was 11μM, and the Ki value of purpurin and alizarin against CYP1B1 was 0.7μM2 and 0.5μM, respectively. We also examined the effects of these pigments on the mutagenicities of MeIQx and B[a]P in the Ames test, using Salmonella typhimurium TA1538 co-expressing each form of human CYP and NADPH-cytochrome P450 reductase (OR). The mutagenicity of MeIQx in TA1538 1A2/OR or 1B1/OR was suppressed by purpurin and alizarin but not by carminic acid. Purpurin also reduced the mutagenicity of B[a]P in TA1538 1A1/OR or 1B1/OR. These results suggest that the antigenotoxic activities of purpurin and alizarin can be explained by inhibition of CYP activities responsible for activating the mutagens.

Original languageEnglish
Pages (from-to)147-156
Number of pages10
JournalMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
Volume508
Issue number1-2
DOIs
Publication statusPublished - Oct 31 2002

Fingerprint

Cytochrome P-450 Enzyme System
Carmine
Cytochrome P-450 CYP3A
Anthraquinones
Mutagens
alizarin
purpurin
Cytochrome P-450 CYP2E1
Cytochrome P-450 CYP1A2
NADPH-Ferrihemoprotein Reductase
Cytochrome P-450 CYP1A1
Polycyclic Aromatic Hydrocarbons
Xenobiotics
Salmonella typhimurium
Human Activities
DNA Repair
Isoenzymes
Drosophila
Amines
Food

Keywords

  • Alizarin
  • Anthraquinone food pigment
  • Antimutagenicity
  • Human recombinant CYPs
  • Purpurin

ASJC Scopus subject areas

  • Health, Toxicology and Mutagenesis
  • Molecular Biology

Cite this

Inhibition of human cytochrome P450 1B1, 1A1 and 1A2 by antigenotoxic compounds, purpurin and alizarin. / Takahashi, Eizo; Fujita, Ken Ichi; Kamataki, Tetsuya; Arimoto, Sakae; Okamoto, Keinosuke; Negishi, Tomoe.

In: Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis, Vol. 508, No. 1-2, 31.10.2002, p. 147-156.

Research output: Contribution to journalArticle

@article{900c7a1ec7ec49449932a2e0838decbc,
title = "Inhibition of human cytochrome P450 1B1, 1A1 and 1A2 by antigenotoxic compounds, purpurin and alizarin",
abstract = "Recently we have shown that anthraquinone food pigments such as purpurin and alizarin suppress the genotoxic activities of several mutagens including heterocyclic amines and polycyclic aromatic hydrocarbons in the Drosophila DNA repair test and in the Ames test. To investigate the mechanism of this inhibition, we have now examined the effects of these anthraquinone pigments on enzymes that metabolize xenobiotics. The activities of eight human recombinant cytochrome P450 (CYP) isozymes were measured in the presence of purpurin, alizarin or carminic acid. Purpurin and alizarin strongly inhibited the activities of CYP1A1, CYP1A2 and CYP1B1, and weakly suppressed those of CYP2A6 and CYP2E1 in a dose-dependent manner, but did not inhibit those of CYP2C19, CYP3A4 and CYP3A5. Carminic acid did not affect the activities of any CYPs tested. CYP1B1 was the most strongly affected CYP molecule by purpurin and alizarin among CYPs examined in this study. From kinetic analysis, it was shown that the inhibition by purpurin on CYP1B1 was both competitive and non-competitive, and that by alizarin was competitive. The values of slopes obtained from Lineweaver-Burk plots are proportional to the square of purpurin concentration. This observation suggests that two molecules of purpurin are interacting with one molecule of CYP1B1. The Km value of CYP1B1 was 11μM, and the Ki value of purpurin and alizarin against CYP1B1 was 0.7μM2 and 0.5μM, respectively. We also examined the effects of these pigments on the mutagenicities of MeIQx and B[a]P in the Ames test, using Salmonella typhimurium TA1538 co-expressing each form of human CYP and NADPH-cytochrome P450 reductase (OR). The mutagenicity of MeIQx in TA1538 1A2/OR or 1B1/OR was suppressed by purpurin and alizarin but not by carminic acid. Purpurin also reduced the mutagenicity of B[a]P in TA1538 1A1/OR or 1B1/OR. These results suggest that the antigenotoxic activities of purpurin and alizarin can be explained by inhibition of CYP activities responsible for activating the mutagens.",
keywords = "Alizarin, Anthraquinone food pigment, Antimutagenicity, Human recombinant CYPs, Purpurin",
author = "Eizo Takahashi and Fujita, {Ken Ichi} and Tetsuya Kamataki and Sakae Arimoto and Keinosuke Okamoto and Tomoe Negishi",
year = "2002",
month = "10",
day = "31",
doi = "10.1016/S0027-5107(02)00212-9",
language = "English",
volume = "508",
pages = "147--156",
journal = "Mutation Research",
issn = "0027-5107",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - Inhibition of human cytochrome P450 1B1, 1A1 and 1A2 by antigenotoxic compounds, purpurin and alizarin

AU - Takahashi, Eizo

AU - Fujita, Ken Ichi

AU - Kamataki, Tetsuya

AU - Arimoto, Sakae

AU - Okamoto, Keinosuke

AU - Negishi, Tomoe

PY - 2002/10/31

Y1 - 2002/10/31

N2 - Recently we have shown that anthraquinone food pigments such as purpurin and alizarin suppress the genotoxic activities of several mutagens including heterocyclic amines and polycyclic aromatic hydrocarbons in the Drosophila DNA repair test and in the Ames test. To investigate the mechanism of this inhibition, we have now examined the effects of these anthraquinone pigments on enzymes that metabolize xenobiotics. The activities of eight human recombinant cytochrome P450 (CYP) isozymes were measured in the presence of purpurin, alizarin or carminic acid. Purpurin and alizarin strongly inhibited the activities of CYP1A1, CYP1A2 and CYP1B1, and weakly suppressed those of CYP2A6 and CYP2E1 in a dose-dependent manner, but did not inhibit those of CYP2C19, CYP3A4 and CYP3A5. Carminic acid did not affect the activities of any CYPs tested. CYP1B1 was the most strongly affected CYP molecule by purpurin and alizarin among CYPs examined in this study. From kinetic analysis, it was shown that the inhibition by purpurin on CYP1B1 was both competitive and non-competitive, and that by alizarin was competitive. The values of slopes obtained from Lineweaver-Burk plots are proportional to the square of purpurin concentration. This observation suggests that two molecules of purpurin are interacting with one molecule of CYP1B1. The Km value of CYP1B1 was 11μM, and the Ki value of purpurin and alizarin against CYP1B1 was 0.7μM2 and 0.5μM, respectively. We also examined the effects of these pigments on the mutagenicities of MeIQx and B[a]P in the Ames test, using Salmonella typhimurium TA1538 co-expressing each form of human CYP and NADPH-cytochrome P450 reductase (OR). The mutagenicity of MeIQx in TA1538 1A2/OR or 1B1/OR was suppressed by purpurin and alizarin but not by carminic acid. Purpurin also reduced the mutagenicity of B[a]P in TA1538 1A1/OR or 1B1/OR. These results suggest that the antigenotoxic activities of purpurin and alizarin can be explained by inhibition of CYP activities responsible for activating the mutagens.

AB - Recently we have shown that anthraquinone food pigments such as purpurin and alizarin suppress the genotoxic activities of several mutagens including heterocyclic amines and polycyclic aromatic hydrocarbons in the Drosophila DNA repair test and in the Ames test. To investigate the mechanism of this inhibition, we have now examined the effects of these anthraquinone pigments on enzymes that metabolize xenobiotics. The activities of eight human recombinant cytochrome P450 (CYP) isozymes were measured in the presence of purpurin, alizarin or carminic acid. Purpurin and alizarin strongly inhibited the activities of CYP1A1, CYP1A2 and CYP1B1, and weakly suppressed those of CYP2A6 and CYP2E1 in a dose-dependent manner, but did not inhibit those of CYP2C19, CYP3A4 and CYP3A5. Carminic acid did not affect the activities of any CYPs tested. CYP1B1 was the most strongly affected CYP molecule by purpurin and alizarin among CYPs examined in this study. From kinetic analysis, it was shown that the inhibition by purpurin on CYP1B1 was both competitive and non-competitive, and that by alizarin was competitive. The values of slopes obtained from Lineweaver-Burk plots are proportional to the square of purpurin concentration. This observation suggests that two molecules of purpurin are interacting with one molecule of CYP1B1. The Km value of CYP1B1 was 11μM, and the Ki value of purpurin and alizarin against CYP1B1 was 0.7μM2 and 0.5μM, respectively. We also examined the effects of these pigments on the mutagenicities of MeIQx and B[a]P in the Ames test, using Salmonella typhimurium TA1538 co-expressing each form of human CYP and NADPH-cytochrome P450 reductase (OR). The mutagenicity of MeIQx in TA1538 1A2/OR or 1B1/OR was suppressed by purpurin and alizarin but not by carminic acid. Purpurin also reduced the mutagenicity of B[a]P in TA1538 1A1/OR or 1B1/OR. These results suggest that the antigenotoxic activities of purpurin and alizarin can be explained by inhibition of CYP activities responsible for activating the mutagens.

KW - Alizarin

KW - Anthraquinone food pigment

KW - Antimutagenicity

KW - Human recombinant CYPs

KW - Purpurin

UR - http://www.scopus.com/inward/record.url?scp=0037206613&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037206613&partnerID=8YFLogxK

U2 - 10.1016/S0027-5107(02)00212-9

DO - 10.1016/S0027-5107(02)00212-9

M3 - Article

C2 - 12379470

AN - SCOPUS:0037206613

VL - 508

SP - 147

EP - 156

JO - Mutation Research

JF - Mutation Research

SN - 0027-5107

IS - 1-2

ER -