METABONOMICS APPROACH TO BIOMARKER DISCOVERY Volume VI: Dose and Time Response of Liver Toxicant

Abstract : The work described in the following report was initiated to investigate the possibility of using novel biotechnologies for the discovery, down-selection, and pre-validation of biomarkers of toxic substance effects within the warfighter prior to health and operational performance decrement. Using the biotechnology of metabonomics, this effort focused on using nuclear magnetic resonance (NMR) spectroscopy and ultra pressure liquid chromatography mass spectrometry (UPLC/MS) for identification of liver-selective toxic effects following exposure to a known hepatotoxicant (alpha-naphthylisothiocyanate; ANIT) that induces cholestasis. Urine samples were analyzed by NMR spectroscopy and UPLC/MS and the data processed and analyzed by principal component analysis, linear discriminant analysis, and hierarchical clustering analysis. NMR- and UPLC/MS-based urinary metabonomics were sensitive enough to detect ANIT-induced toxic effects with respect to both dose and time. Understanding the cellular response to chemical exposure at the molecular level will not only facilitate the elucidation of the mechanism of chemical toxicity, but also allow accurate prediction of chemical toxicity and phenotypic outcome. Ultimately, this will lead to the identification of novel biomarkers for rapid monitoring and prediction of health hazards to the warfighter associated with chemical exposure.