title: 1H NMR metabolomics of earthworm responses to polychlorinated biphenyl (PCB) exposure in soil.
abstract: (1)H NMR-based metabolomics was used to examine the metabolic profile of D(2)O-buffer extracted tissues of Eisenia fetida earthworms exposed for 2 days to an artificial soil spiked with sub-lethal concentrations of polychlorinated biphenyls (PCBs) (0, 0.5, 1, 5, 10, or 25 mg/kg Aroclor 1254). Univariate statistical analysis of the identified metabolites revealed a significant increase in ATP concentration in earthworms exposed to the highest soil PCB concentration, but detected no significant changes in other metabolites. However, a multivariate approach which considers alterations in multiple metabolites simultaneously, identified a significant linear relationship between earthworm metabolic profiles and PCB concentration (cross-validated PLS-regression with 7 components, R(2)X = 0.99, R(2)Y = 0.77, Q(2)Y = 0.45, P < 0.001). Significant changes in pair-wise metabolic correlations were also detected as PCB concentration increased. For example, lysine and ATP concentrations showed no apparent correlation in control earthworms (r = 0.22, P = 0.54), but were positively correlated in earthworms from the 25 mg/kg treatment (r = 0.87, P = 0.001). Overall, the observed metabolic responses suggest that PCBs disrupted both carbohydrate (energy) metabolism and membrane (osmolytic) function in E. fetida. The ability of (1)H NMR-based metabolomics to detect these responses suggests that this method offers significant potential for direct assessment of sub-lethal PCB toxicity in soil.
authors.affiliation: Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada.
authors.forename: Melissa L
authors.initials: ML
authors.lastname: Whitfield Åslund
authors.forename: André J
authors.initials: AJ
authors.lastname: Simpson
authors.forename: Myrna J
authors.initials: MJ
authors.lastname: Simpson
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D009682:Magnetic Resonance Spectroscopy; D055442:Metabolome / Q000187:drug effects*; D015999:Multivariate Analysis; D009835:Oligochaeta / Q000187:drug effects* / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D018570:Risk Assessment; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls