title: A metabolomic study on the responses of daphnia magna exposed to silver nitrate and coated silver nanoparticles.
abstract: We examined the short-term toxicity of AgNPs and AgNO3 to Daphnia magna at sublethal levels using (1)H NMR-based metabolomics. Two sizes of polyvinylpyrrolidone-coated AgNPs (10 and 40nm) were synthesized and characterized and their Ag(+) release was studied using centrifugal ultrafiltration and inductively coupled plasma mass spectrometry. Multivariate statistical analysis of the (1)H NMR spectra showed significant changes in the D. magna metabolic profiles following 48h exposure to both AgNP particle sizes and Ag(+) exposure. Most of the metabolic biomarkers for AgNP exposure, including 3-hydroxybutyrate, arginine, lysine and phosphocholine, were identical to those of the Ag(+)-exposed groups, suggesting that the dominant effects of both AgNPs were due to released Ag(+). The observed metabolic changes implied that the released Ag(+) induced disturbance in energy metabolism and oxidative stress, a proposed mechanism of AgNP toxicity. Elevated levels of lactate in all AgNP-treated but not in Ag(+)-treated groups provided evidence for Ag-NP enhanced anaerobic metabolism. These findings show that (1)H NMR-based metabolomics provides a sensitive measure of D. magna response to AgNPs and that further targeted assays are needed to elucidate mechanisms of action of nanoparticle-induced toxicity.
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, no.17, Chunhui Road, Yantai, Shandong 264003, PR China.
authors.forename: LianZhen
authors.initials: L
authors.lastname: Li
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, no.17, Chunhui Road, Yantai, Shandong 264003, PR China. Electronic address: hfwu@yic.ac.cn.
authors.forename: Huifeng
authors.initials: H
authors.lastname: Wu
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, no.17, Chunhui Road, Yantai, Shandong 264003, PR China.
authors.forename: Chenglong
authors.initials: C
authors.lastname: Ji
authors.affiliation: Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
authors.forename: Cornelis A M
authors.initials: CA
authors.lastname: van Gestel
authors.affiliation: Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716, USA.
authors.forename: Herbert E
authors.initials: HE
authors.lastname: Allen
authors.affiliation: National Institute of Public Health and the Environment, Center for Safety of Substances and Products, P.O. Box 1, 3720 BA Bilthoven, The Netherlands; Institute of Environmental Sciences (CML), Leiden University, Leiden, The Netherlands.
authors.forename: Willie J G M
authors.initials: WJ
authors.lastname: Peijnenburg
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000633:toxicity; D004396:Coloring Agents / Q000494:pharmacology; D003621:Daphnia / Q000187:drug effects* / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects; D007773:Lactates / Q000378:metabolism; D055432:Metabolomics; D053768:Metal Nanoparticles / Q000633:toxicity*; D015999:Multivariate Analysis; D018384:Oxidative Stress / Q000187:drug effects; D010316:Particle Size; D012834:Silver / Q000633:toxicity*; D012835:Silver Nitrate / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000900:Anti-Bacterial Agents; D004396:Coloring Agents; D007773:Lactates; D014874:Water Pollutants, Chemical; D012834:Silver; D012835:Silver Nitrate
keywords: Daphnia magna; Metabolomics; Silver ion; Silver nanoparticle; Sublethal toxicity