title: Identification of early biomarkers during acetaminophen-induced hepatotoxicity by fourier transform infrared microspectroscopy.
abstract: Acetaminophen is a widely prescribed drug used to relieve pain and fever; however, it is a leading cause of drug-induced liver injury and a burden on public healthcare. In this study, hepatotoxicity in mice post oral dosing of acetaminophen was investigated using liver and sera samples with Fourier Transform Infrared microspectroscopy. The infrared spectra of acetaminophen treated livers in BALB/c mice show decrease in glycogen, increase in amounts of cholesteryl esters and DNA respectively. Rescue experiments using L-methionine demonstrate that depletion in glycogen and increase in DNA are abrogated with pre-treatment, but not post-treatment, with L-methionine. This indicates that changes in glycogen and DNA are more sensitive to the rapid depletion of glutathione. Importantly, analysis of sera identified lowering of glycogen and increase in DNA and chlolesteryl esters earlier than increase in alanine aminotransferase, which is routinely used to diagnose liver damage. In addition, these changes are also observed in C57BL/6 and Nos2(-/-) mice. There is no difference in the kinetics of expression of these three molecules in both strains of mice, the extent of damage is similar and corroborated with ALT and histological analysis. Quantification of cytokines in sera showed increase upon APAP treatment. Although the levels of Tnfα and Ifnγ in sera are not significantly affected, Nos2(-/-) mice display lower Il6 but higher Il10 levels during this acute model of hepatotoxicity. Overall, this study reinforces the growing potential of Fourier Transform Infrared microspectroscopy as a fast, highly sensitive and label-free technique for non-invasive diagnosis of liver damage. The combination of Fourier Transform Infrared microspectroscopy and cytokine analysis is a powerful tool to identify multiple biomarkers, understand differential host responses and evaluate therapeutic regimens during liver damage and, possibly, other diseases.
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, India.
authors.forename: Rekha
authors.initials: R
authors.lastname: Gautam
authors.forename: Bhagawat
authors.initials: B
authors.lastname: Chandrasekar
authors.forename: Mukta
authors.initials: M
authors.lastname: Deobagkar-Lele
authors.forename: Srabanti
authors.initials: S
authors.lastname: Rakshit
authors.forename: Vinay
authors.initials: V
authors.lastname: Kumar B N
authors.forename: Siva
authors.initials: S
authors.lastname: Umapathy
authors.forename: Dipankar
authors.initials: D
authors.lastname: Nandi
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000009:adverse effects*; D000818:Animals; D015415:Biomarkers / Q000097:blood / Q000378:metabolism*; D056486:Chemical and Drug Induced Liver Injury / Q000097:blood / Q000378:metabolism* / Q000473:pathology*; D002788:Cholesterol Esters / Q000097:blood / Q000378:metabolism; D016207:Cytokines / Q000097:blood / Q000378:metabolism; D004247:DNA / Q000097:blood / Q000378:metabolism; D006003:Glycogen / Q000097:blood / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008715:Methionine / Q000009:adverse effects; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D015415:Biomarkers; D002788:Cholesterol Esters; D016207:Cytokines; D000082:Acetaminophen; D006003:Glycogen; D004247:DNA; D008715:Methionine; D052247:Nitric Oxide Synthase Type II