NMR and Pattern Recognition Studies on the Time-Related Metabolic Effects of α-Naphthylisothiocyanate on Liver, Urine, and Plasma in the Rat:  An Integrative Metabonomic Approach

Abstract

We present here a novel integrative metabonomic approach to probe toxic effects of drugs in experimental animals using alpha-naphthylisothiocyanate (ANIT) as a model hepatotoxicant. Male Han-Wistar rats were dosed with ANIT (150 mg/kg, n = 25), and plasma and liver samples were collected for NMR and magic-angle spinning (MAS) NMR spectroscopy at 3, 7, 24, 31, and 168 h postdosing. Urine was collected continuously for 3 days prior to dosing and up to 168 h postdose. Histopathology and plasma clinical chemistry was also performed at all time points. Liver samples were analyzed either intact by 600 MHz 1H MAS NMR techniques or using high resolution (liquid state) 1H NMR of water-acetonitrile extracts. These data were related to sequential 1H NMR measurements in urine and plasma using pattern recognition methods. 1D 1H NMR spectra were data-reduced and analyzed using principal components analysis (PCA) to show the time-dependent biochemical variations induced by ANIT toxicity. From the eigenvector loadings of the PCA, those regions of the 1H NMR spectra and hence the combinations of endogenous metabolites marking the main phase of the toxic episode were identified. The ANIT-induced biochemical manifestations included a hepatic lipidosis associated with hyperlipidaemia; hyperglycaemia and glycosuria; increased urinary excretion of taurine and creatine; a shift in energy metabolism characterized by increased plasma ketone bodies with reduced urinary excretion of tricarboxylic acid cycle intermediates and raised hepatic bile acids leading to bile aciduria. The integration of metabolic data derived from several sources gives a holistic approach to the study of time-related toxic effects in the intact system and enables the characterization of key metabolic effects during the development and recovery from a toxic lesion.

Metabolomic Analysis of the Effects of Motorcycle Exhaust on Rat Testes and Liver

“…The results suggested that the induction of lipid degradation removed excessive lipids. Similar decreases in lipids that were accompanied by increases in lipid catabolism products were also observed in the livers of rats treated with alpha-naphthylisothiocyanate and high doses of triadimefon (Waters et al, 2001;Ekman et al, 2006).…”

A toxicologist's guide to biomarkers of hepatic response

“…Other recent studies in rats have demonstrated that NMR-based metabonomic techniques can permit visualization of key time periods in the development of toxic injury enabling the identification of lesionspecific, matrix-specific biomarkers of cholestasis and hepatotoxicity. 74 Further work, especially studies using NMR spectroscopy, appears to be promising and can easily be extended to humans in many cases. Using pattern-recognition methods such as principal component analysis, 71 a combination of several biomarkers in peripheral fluids may provide greater sensitivity and selectivity than possible with individual markers.…”

Metabolic responses in gills of Manila clam Ruditapes philippinarum exposed to copper using NMR-based metabolomics

“…Therefore, some of these enzymatic parameters such as activity of acetylcholinesterase have been used as biomarkers for the heavy metal monitoring (Matozzo et al, 2005). With the development of system biology, metabolomics, one of the techniques of system biology, has been widely applied in drug toxicity studies, disease diagnosis, functional genomics and environmental sciences (Wu et al, 2005;Waters et al, 2001;Marchesi et al, 2007;Gavaghan et al, 2002;Griffin et al, 2004;Brindle et al, 2002;Bundy et al, 2004;Viant et al, 2006a,b;Katsiadaki et al, 2009). The application of proton nuclear magnetic resonance (NMR) spectroscopy combined with pattern recognition methods to detect the responses of low molecular weight metabolites (<1000 Da) to toxicants or environmental contaminants has been demonstrated in both terrestrial vertebrate and invertebrate systems relevant to environmental toxicology (Bundy et al, 2002;Griffin et al, 2000;Fiehn, 2002).…”