Skip to main content
Advertisement

Main menu

  • Home
  • Articles
    • Current Issue
    • Fast Forward
    • Latest Articles
    • Special Sections
    • Archive
  • Information
    • Instructions to Authors
    • Submit a Manuscript
    • FAQs
    • For Subscribers
    • Terms & Conditions of Use
    • Permissions
  • Editorial Board
  • Alerts
    • Alerts
    • RSS Feeds
  • Virtual Issues
  • Feedback
  • Submit
  • Other Publications
    • Drug Metabolism and Disposition
    • Journal of Pharmacology and Experimental Therapeutics
    • Molecular Pharmacology
    • Pharmacological Reviews
    • Pharmacology Research & Perspectives
    • ASPET

User menu

  • My alerts
  • Log in
  • Log out
  • My Cart

Search

  • Advanced search
Drug Metabolism & Disposition
  • Other Publications
    • Drug Metabolism and Disposition
    • Journal of Pharmacology and Experimental Therapeutics
    • Molecular Pharmacology
    • Pharmacological Reviews
    • Pharmacology Research & Perspectives
    • ASPET
  • My alerts
  • Log in
  • Log out
  • My Cart
Drug Metabolism & Disposition

Advanced Search

  • Home
  • Articles
    • Current Issue
    • Fast Forward
    • Latest Articles
    • Special Sections
    • Archive
  • Information
    • Instructions to Authors
    • Submit a Manuscript
    • FAQs
    • For Subscribers
    • Terms & Conditions of Use
    • Permissions
  • Editorial Board
  • Alerts
    • Alerts
    • RSS Feeds
  • Virtual Issues
  • Feedback
  • Submit
  • Visit dmd on Facebook
  • Follow dmd on Twitter
  • Follow ASPET on LinkedIn
Research ArticleArticle

Studies on Cytochrome P-450-Mediated Bioactivation of Diclofenac in Rats and in Human Hepatocytes: Identification of Glutathione Conjugated Metabolites

Wei Tang, Ralph A. Stearns, Stelvio M. Bandiera, Yong Zhang, Conrad Raab, Matthew P. Braun, Dennis C. Dean, Jianmei Pang, Kwan H. Leung, George A. Doss, John R. Strauss, Gloria Y. Kwei, Thomas H. Rushmore, Shuet-Hing L. Chiu and Thomas A. Baillie
Drug Metabolism and Disposition March 1999, 27 (3) 365-372;
Wei Tang
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Ralph A. Stearns
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Stelvio M. Bandiera
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Yong Zhang
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Conrad Raab
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Matthew P. Braun
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Dennis C. Dean
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Jianmei Pang
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Kwan H. Leung
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
George A. Doss
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
John R. Strauss
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Gloria Y. Kwei
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Thomas H. Rushmore
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Shuet-Hing L. Chiu
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Thomas A. Baillie
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • Article
  • Figures & Data
  • Info & Metrics
  • eLetters
  • PDF
Loading

Abstract

The nonsteroidal anti-inflammatory drug diclofenac causes a rare but potentially fatal hepatotoxicity that may be associated with the formation of reactive metabolites. In this study, three glutathione (GSH) adducts, namely 5-hydroxy-4-(glutathion-S-yl)diclofenac (M1), 4′-hydroxy-3′-(glutathion-S-yl)diclofenac (M2), and 5-hydroxy-6-(glutathion-S-yl)diclofenac (M3), were identified by liquid chromatography-tandem mass spectrometry analysis of bile from Sprague-Dawley rats injected i.p. with a single dose of diclofenac (200 mg/kg). These adducts presumably were formed via hepatic cytochrome P-450 (CYP)-catalyzed oxidation of diclofenac to reactive benzoquinone imines that were trapped by GSH conjugation. In support of this hypothesis, M1, M2, and M3 were generated from diclofenac in incubations with rat liver microsomes in the presence of NADPH and GSH. Increases in adduct formation were observed when incubations were performed with liver microsomes from phenobarbital- or dexamethasone-treated rats. Adduct formation was inhibited by polyclonal antibodies against CYP2B, CYP2C, and CYP3A (40–50% inhibition at 5 mg of IgG/nmol of CYP) but not by an antibody against CYP1A. Maximal inhibition was obtained when the three inhibitory antibodies were used in a cocktail fashion (70–80% inhibition at 2.5 mg of each IgG/nmol of CYP). These data suggest that diclofenac undergoes biotransformation to reactive metabolites in rats and that CYP isoforms of the 2B, 2C, and 3A subfamilies are involved in this bioactivation process. With respect to CYP2C isoforms, rat hepatic CYP2C7 and CYP2C11 were implicated as mediators of the bioactivation based on immunoinhibition studies using antibodies specific to CYP2C7 and CYP2C11. Screening for GSH adducts also was carried out in human hepatocyte cultures containing diclofenac, and M1, M2, and M3 again were detected. It is possible, therefore, that reactive benzoquinone imines may be formed in vivo in humans and contribute to diclofenac-mediated hepatic injury.

Footnotes

  • Send reprint requests to: Dr. Wei Tang, Department of Drug Metabolism, Merck & Co., P.O. Box 2000, RY80L-109, Rahway, NJ 07065. E-mail: wei_tang{at}merck.com

  • A preliminary account of this study was presented at Experimental Biology, San Francisco, CA, April 1998.

  • Abbreviations used are::
    CYP
    cytochrome P-450
    CID
    collision-induced dissociation
    Dex
    dexamethasone
    GSH
    glutathione
    LC/MS/MS
    liquid chromatography-tandem mass spectrometry
    M1
    5-OH-4-GS-diclofenac or 5-hydroxy-4-(glutathion-S-yl)diclofenac
    M2
    4′-OH-3′-GS-diclofenac or 4′-hydroxy-3′-(glutathion-S-yl)diclofenac
    M3
    5-OH-6-GS-diclofenac or 5-hydroxy-6-(glutathion-S-yl)diclofenac
    PB
    phenobarbital
    TFA
    trifluoroacetic acid
    • Received September 4, 1998.
    • Accepted December 2, 1998.
  • The American Society for Pharmacology and Experimental Therapeutics
View Full Text

 

DMD articles become freely available 12 months after publication, and remain freely available for 5 years. 

Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page. 

 

  • Click here for information on institutional subscriptions.
  • Click here for information on individual ASPET membership.

 

Log in using your username and password

Forgot your user name or password?

Purchase access

You may purchase access to this article. This will require you to create an account if you don't already have one.
PreviousNext
Back to top

In this issue

Drug Metabolism and Disposition: 27 (3)
Drug Metabolism and Disposition
Vol. 27, Issue 3
1 Mar 1999
  • Table of Contents
  • About the Cover
  • Index by author
Download PDF
Article Alerts
Sign In to Email Alerts with your Email Address
Email Article

Thank you for sharing this Drug Metabolism & Disposition article.

NOTE: We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail. We do not retain these email addresses.

Enter multiple addresses on separate lines or separate them with commas.
Studies on Cytochrome P-450-Mediated Bioactivation of Diclofenac in Rats and in Human Hepatocytes: Identification of Glutathione Conjugated Metabolites
(Your Name) has forwarded a page to you from Drug Metabolism & Disposition
(Your Name) thought you would be interested in this article in Drug Metabolism & Disposition.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Research ArticleArticle

Studies on Cytochrome P-450-Mediated Bioactivation of Diclofenac in Rats and in Human Hepatocytes: Identification of Glutathione Conjugated Metabolites

Wei Tang, Ralph A. Stearns, Stelvio M. Bandiera, Yong Zhang, Conrad Raab, Matthew P. Braun, Dennis C. Dean, Jianmei Pang, Kwan H. Leung, George A. Doss, John R. Strauss, Gloria Y. Kwei, Thomas H. Rushmore, Shuet-Hing L. Chiu and Thomas A. Baillie
Drug Metabolism and Disposition March 1, 1999, 27 (3) 365-372;

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero

Share
Research ArticleArticle

Studies on Cytochrome P-450-Mediated Bioactivation of Diclofenac in Rats and in Human Hepatocytes: Identification of Glutathione Conjugated Metabolites

Wei Tang, Ralph A. Stearns, Stelvio M. Bandiera, Yong Zhang, Conrad Raab, Matthew P. Braun, Dennis C. Dean, Jianmei Pang, Kwan H. Leung, George A. Doss, John R. Strauss, Gloria Y. Kwei, Thomas H. Rushmore, Shuet-Hing L. Chiu and Thomas A. Baillie
Drug Metabolism and Disposition March 1, 1999, 27 (3) 365-372;
del.icio.us logo Digg logo Reddit logo Twitter logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Google Plus One

Jump to section

  • Article
    • Abstract
    • Materials and Methods
    • Results
    • Discussion
    • Acknowledgments
    • Footnotes
    • References
  • Figures & Data
  • Info & Metrics
  • eLetters
  • PDF

Related Articles

Cited By...

More in this TOC Section

  • TMDD Affects PK of IL-10 Fc-fusion Proteins
  • Uptake as the RDS in Pevonedistat Hepatic Clearance
  • In vitro downregulation of OATP1B1 by retinoids
Show more Article

Similar Articles

Advertisement
  • Home
  • Alerts
Facebook   Twitter   LinkedIn   RSS

Navigate

  • Current Issue
  • Fast Forward by date
  • Fast Forward by section
  • Latest Articles
  • Archive
  • Search for Articles
  • Feedback
  • ASPET

More Information

  • About DMD
  • Editorial Board
  • Instructions to Authors
  • Submit a Manuscript
  • Customized Alerts
  • RSS Feeds
  • Subscriptions
  • Permissions
  • Terms & Conditions of Use

ASPET's Other Journals

  • Journal of Pharmacology and Experimental Therapeutics
  • Molecular Pharmacology
  • Pharmacological Reviews
  • Pharmacology Research & Perspectives
ISSN 1521-009X (Online)

Copyright © 2022 by the American Society for Pharmacology and Experimental Therapeutics