Metabonomic Assessment of Toxicity of 4-Fluoroaniline, 3,5-Difluoroaniline and 2-Fluoro-4-Methylaniline to the Earthworm Eisenia Veneta (Rosa): Identification of New Endogenous Biomarkers

Abstract

Abstract-High-resolution 1 H nuclear magnetic resonance (NMR) spectroscopy can be used to produce a biochemical fingerprint of low-molecular-weight metabolites from complex biological mixtures such as tissue extracts and biofluids. Changes in such fingerprint profiles can be used to characterize the effects of toxic insult in in vivo systems. The technique is nonselective and requires little sample preparation or derivatization. In the present study, earthworms (Eisenia veneta) were exposed to three different model xenobiotics by a standard filter paper contact test, and toxicant-induced biochemical changes were then investigated by characterizing the changes in endogenous metabolites visible in 600-MHz 1 H NMR spectra of tissue extracts. The NMR spectral intensities were converted to discrete numerical values and tabulated in order to provide data matrices suitable for multivariate analysis. Principal component analysis showed that changes had occurred in the biochemical profiles relative to the undosed controls. The 2-fluoro-4-methylaniline-treated worms showed a decrease in a resonance from a compound identified as 2-hexyl-5-ethyl-3-furansulfonate using a combination of high-performance liquid chromatography (HPLC)-Fourier transform mass spectrometry (IonSpec, Lake Forest, CA, USA) and 1 H and 13 C NMR spectroscopy. An increase in inosine monophosphate was also observed. The 4-fluoroaniline-treated worms showed a decrease in maltose concentrations, and 3,5-difluoroaniline exerted the same effect as 2-fluoro-4-methylaniline but to a lesser extent. These changes could potentially be used as novel biomarkers of xenobiotic toxicity and could be used to determine the mechanism of action of other toxic chemicals.

Proteomic and metabolomic analysis of earthworm Eisenia fetida exposed to different concentrations of 2,2′,4,4′-tetrabromodiphenyl ether

“…The similar result was observed in phenanthrene-treated E. fetida [29]. Previous studies showed that hydrophobic organic contaminants could result in an enhanced energy metabolism marked by decreased maltose and increased amino acids due to protein breakdown [28,45]. In our case, the elevated amino acids including glycine and alanine were observed in both 10 and 100 μg/L BDE 47-treated groups.…”

“…HEFS was identified in diverse earthworm species including Eisenia veneta, Lumbricus rubellus, Aporrectodea caliginosa and E. fetida [27,28,42,43]. Although the function of HEFS in earthworms was not fully understood, it was suggested that HEFS might play a role in membrane stabilization due to its amphiphilic property [27,28].…”

“…Although the function of HEFS in earthworms was not fully understood, it was suggested that HEFS might play a role in membrane stabilization due to its amphiphilic property [27,28]. The decrease of HEFS could mean that BDE 47 induced disturbance in membrane stabilization in E. fetida at concentrations ranged from 0.1 to 100 μg/L.…”

“…In the terrestrial system, earthworms are excellent model organisms and have been widely used as preferable bioindicators in soil ecotoxicology [27,28]. Some recent studies have shown that both NMR-based metabolomics and 2-DE-based proteomics on earthworm Eisenia fetida have great potential to elucidate the toxicological effects and mechanisms induced by environmental contaminants, such as heavy metals (e.g., cadmium) and organic chemicals (e.g., phenanthrene) [29,30].…”

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

“…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). 1 H NMR spectroscopy is suitable for the detection of a large range of endogenous low molecular weight metabolites in an organ or cells, since practically all metabolite molecules contain protons.…”