title: Comparative metabonomic analysis of hepatotoxicity induced by acetaminophen and its less toxic meta-isomer.
abstract: The leading cause of drug-induced liver injury in the developed world is overdose with N-acetyl-p-aminophenol (APAP). A comparative metabonomic approach was applied to the study of both xenobiotic and endogenous metabolic profiles reflective of in vivo exposure to APAP (300 mg/kg) and its structural isomer N-acetyl-m-aminophenol (AMAP; 300 mg/kg) in C57BL/6J mice, which was anchored with histopathology. Liver and urine samples were collected at 1 h, 3 h and 6 h post-treatment and analyzed by1H nuclear magnetic resonance (NMR) spectroscopy and gas chromatography-mass spectrometry (liver only). Histopathology revealed the presence of centrilobular necrosis from 3 h post-APAP treatment, while an AMAP-mediated necrotic endpoint was not observed within the timescale of this study, yet two of five treated mice showed minimal centrilobular eosinophilia. The1H-NMR xenobiotic metabolic profile of APAP-treated animals comprised of mercapturate (urine and liver) and glutathionyl (liver) conjugates detected at 1 h post-treatment. This finding corroborated the hepatic endogenous metabolic profile which showed depletion of glutathione from 1 h onwards. In contrast, AMAP glutathionyl conjugates were not detected, nor was AMAP-induced depletion of hepatic glutathione observed. APAP administration induced significant endogenous hepatic metabolic perturbations, primarily linked to oxidative and energetic stress, and perturbation of amino acid metabolism. Early depletion of glutathione was followed by depletion of additional sulfur-containing metabolites, while altered levels of mitochondrial and glycolytic metabolites indicated a disruption of energy homeostasis. In contrast, AMAP administration caused minimal, transient, distinct metabolic perturbations and by 6 h the metabolic profiles of AMAP-treated mice were indistinguishable from those of controls.
authors.affiliation: Biomolecular Medicine, Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, London, SW7 2AZ, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Kyriakides
authors.affiliation: Biomolecular Medicine, Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, London, SW7 2AZ, UK.
authors.forename: Lea
authors.initials: L
authors.lastname: Maitre
authors.affiliation: School of Pharmacy, Pacific University, Hillsboro, OR, 97123, USA.
authors.forename: Brendan D
authors.initials: BD
authors.lastname: Stamper
authors.affiliation: Departments of Medicinal Chemistry and Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Isaac
authors.initials: I
authors.lastname: Mohar
authors.affiliation: Departments of Medicinal Chemistry and Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Terrance J
authors.initials: TJ
authors.lastname: Kavanagh
authors.affiliation: ToxPath Sciences Ltd, 1 Troutbeck Avenue, Congleton, Cheshire, CW12 4JA, UK.
authors.forename: John
authors.initials: J
authors.lastname: Foster
authors.affiliation: Biomolecular Medicine, Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, London, SW7 2AZ, UK.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Wilson
authors.affiliation: Biomolecular Medicine, Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, London, SW7 2AZ, UK.
authors.forename: Elaine
authors.initials: E
authors.lastname: Holmes
authors.affiliation: Departments of Medicinal Chemistry and Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Sidney D
authors.initials: SD
authors.lastname: Nelson
authors.affiliation: Biomolecular Medicine, Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London, London, SW7 2AZ, UK. m.coen@imperial.ac.uk.
authors.forename: Muireann
authors.initials: M
authors.lastname: Coen
mesh_terms: D000082:Acetaminophen / Q000009:adverse effects* / Q000031:analogs & derivatives / Q000737:chemistry / Q000493:pharmacokinetics; D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000378:metabolism / Q000652:urine; D018712:Analgesics, Non-Narcotic / Q000009:adverse effects* / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics; D000818:Animals; D015415:Biomarkers / Q000097:blood / Q000378:metabolism / Q000652:urine; D001711:Biotransformation; D056486:Chemical and Drug Induced Liver Injury / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D004734:Energy Metabolism / Q000187:drug effects; D004802:Eosinophilia / Q000209:etiology; D005978:Glutathione / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000378:metabolism; D007536:Isomerism; D008099:Liver / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D055432:Metabolomics / Q000379:methods; D008810:Mice, Inbred C57BL; D009336:Necrosis; D018384:Oxidative Stress / Q000187:drug effects; D013047:Specific Pathogen-Free Organisms; D014018:Tissue Distribution
chemical_list: D018712:Analgesics, Non-Narcotic; D015415:Biomarkers; D000082:Acetaminophen; D005978:Glutathione; D000111:Acetylcysteine
keywords: Hepatotoxicity; Metabonomics/Metabolic Phenotyping; N-acetyl-m-aminophenol (AMAP); N-acetyl-p-aminophenol (APAP); Nuclear magnetic resonance spectroscopy