Metabolic responses in zebrafish (Danio rerio) exposed to zinc and cadmium by nuclear magnetic resonance -based metabolomics

ABSTRACT

Heavy metals are common marine and soil pollutants that are mainly the result of industrial activity, and are a threat to the environment and human health. In this study, ¹H nuclear magnetic resonance (NMR)-based metabolomics was applied to adult Danio rerio to monitor the metabolic change as a response to ZnCl₂ and CdCl₂ exposure at different concentrations for 72 h. NMR spectroscopy was used to identify and quantify the metabolites extracted from D. rerio. The metabolite profiles of the control and heavy metal exposed group were classified by partial least squares – discriminant analysis (PLS-DA) analysis, and potential contaminant-specific biomarkers were suggested. For the ZnCl₂-exposed zebrafish, the levels of ATP, aspartate and NAD⁺ were increased, whereas the levels of formate, inosine, hypoxanthine and succinate decreased. In addition, the CdCl₂-exposed zebrafish showed an increase in the levels of ATP and formate and a decrease in the levels of glutamate, inosine and glutathione. Overall, Zn and Cd may lead to neurotoxicity, disturbances in the energy metabolism and oxidative stress. Our finding demonstrated that the application of NMR-based metabolomics might be useful for detecting the toxicity caused by sub-lethal concentrations of heavy metal contaminants in the environment.

KEYWORDS:

• Cadmium
• zinc
• metabolomics
• ¹H NMR spectroscopy
• zebrafish (Danio rerio)

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2011-0008894)/Ministry of Oceans and Fisheries (20150242).