Targeted metabolomics of Gammarus pulex following controlled exposures to selected pharmaceuticals in water

Abstract

The effects of pharmaceuticals and personal care products (PPCPs) on aquatic organisms represent a significant current concern. Herein, a targeted metabolomics approach using liquid chromatography-high resolution mass spectrometry (LC-HRMS) is presented to characterise concentration changes in 29 selected metabolites following exposures of aquatic invertebrates, Gammarus pulex, to pharmaceuticals. Method performance revealed excellent linearity (R2 > 0.99), precision (0.1–19%) and lower instrumental limits of detection (0.002–0.20 ng) for all metabolites studied. Three pharmaceuticals were selected representing the low, middle and high range of measured acute measured toxicities (of a total of 26 compounds). Gammarids were exposed to both the no-observed-adverse-effect-level (NOAEL) and the lowest-observed-adverse-effect-level (LOAEL) of triclosan (0.1 and 0.3 mg L− 1), nimesulide (0.5 and 1.4 mg L− 1) and propranolol (100 and 153 mg L− 1) over 24 h. Quantitative metabolite profiling was then performed. Significant changes in metabolite concentrations relative to controls are presented and display distinct clustered trends for each pharmaceutical. Approximately 37% (triclosan), 33% (nimesulide) and 46% (propranolol) of metabolites showed statistically significant time-related effects. Observed changes are also discussed with respect to internal concentrations of the three pharmaceuticals measured using a method based on pulverised liquid extraction, solid phase extraction and LC-MS/MS. Potential metabolic pathways that may be affected by such exposures are also discussed. This represents the first study focussing on quantitative, targeted metabolomics of this lower trophic level benthic invertebrate that may elucidate biomarkers for future risk assessment.

A review of the pharmaceutical exposome in aquatic fauna

“…In addition to screening for small micro-contaminant molecules, screening of biota for thousands of endogenous metabolites can be achieved simultaneously (i.e. metabolomics) ( Gómez-Canela et al., 2016 ; Toyota et al., 2016a ; Viant and Sommer, 2013 ). Environmental metabolomics-based studies have focused on the effect of biotic and abiotic stressors on both terrestrial and aquatic organisms and several have used nuclear magnetic resonance spectroscopy (NMR) and/or GC/LC-MS ( Broeckling et al., 2005 ; Bundy et al., 2004 ; Bussell et al., 2008 ; Griffin et al., 2000 ; Hines et al., 2007 ; Skelton et al., 2014 ).…”

“…Furthermore, glucocorticoid and lipid metabolism was disrupted and a 470-fold decrease in palmitoyl carnitine concentrations were observed (used in fatty acid transport). We also recently studied sub-lethal concentration exposures of three pharmaceutical compounds (propranolol, triclosan and nimesulide) to G. pulex ( Gómez-Canela et al., 2016 ). Metabolic changes in a range of amino acids and other metabolites were identified and quantified using SIL-IS.…”

In-plate toxicometabolomics of single zebrafish embryos

“…The only non-lipid related metabolite feature we identified with a level 1 certainty was phenylalanine, which has also been reported in a previous metabolomics study on PPL exposure. 46 The direct inhibition of tyrosine hydroxylase (TH) by PPL is a likely explanation for the relative increase of phenylalanine in the two highest exposure concentrations in our data (Fig. 5b).…”

Assessing the impact of wastewater treatment plant effluent on downstream drinking water-source quality using a zebrafish (Danio Rerio) liver cell-based metabolomics approach

“…Due to advantages that have been discussed elsewhere (Bundy et al, 2009;Lankadurai et al, 2013), metabolomics has been shown to be a particularly useful "-omics" approach for evaluating comprehensive biological responses to various environmental stressors. For example, this approach has been extensively employed to investigate the MOAs of various xenobiotics, including nanoparticles (Ratnasekhar et al, 2015), PPCPs (Gomez-Canela et al, 2016), and EDCs (Davis et al, 2017), through laboratory-based animal (e.g., rodents, fish, and invertebrates) exposures. In addition, field-based metabolomics assessments using on-site exposure of fish have been used successfully to investigate the biological effect of complex contaminant mixtures discharging from both point (e.g., WWTP effluent) and nonpoint sources (Davis et al, 2013;Skelton et al, 2014).…”