Hwa-Kyung Lee
Seoul National University, Republic of Korea
Title: Targeted toxicometabolomics of endosulfan sulfate in adult zebrafish (Danio rerio) using multiple reaction monitoring mode of GC-MS/MS
Biography
Biography: Hwa-Kyung Lee
Abstract
Endosulfan sulfate (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9 methano-2,3,4-benzodioxathiepin-3,3-dioxide) is a major oxidized metabolite of endosulfan which is a broad-spectrum chlorinated cyclodiene insecticide. In this study, we used a GC-MS/MS based targeted metabolomic approach using MRM of metabolite to elucidate the toxicological effects of endosulfan sulfate in adult zebrafish. Zebrafish were exposed to endosulfan sulfate at concentrations of 1/10 LC50 and LC50 for 24 and 48 hours. After exposure, the fish was homogenized with liquid N2, extracted with 50% MeOH solution and dried before TMS derivatization (MSTFA+1% TMCS). On GC-MS/MS (Shimadzu TQ8040) MRM library of 381 metabolites were used for screening to detect overall 170 metabolites in zebrafish whole body. The PLS-DA score plot (SIMCA-P+) showed a good separation between the three experimental groups (control, 1/10 LC50, LC50) of 48 hours samples. Based on the VIP and ANOVA results, 60 metabolites were identified for contributing significantly to the differences in the metabolic profile. Metabolic pathway analysis using MetaboAnalyst 4.0 revealed that those identified metabolites were important for the organism response to endosulfan sulfate. Several pathways were reported by metabolic pathway analysis included aminoacyl-tRNA biosynthesis, valine/leucine/isoleucine biosynthesis, alanine/aspartate/glutamate metabolism, glycerolipid metabolism, arginine/proline metabolism, citrate cycle (TCA cycle), glycine/serine/threonine metabolism, glyoxylate/dicarboxylate metabolism and pentose phosphate pathway. These results suggest that these pathways underwent significant perturbations over the exposure period. This study highlights the application of GC-MS/MS (MRM mode) based targeted metabolomics to understand molecularlevel toxicity of persistent organochlorine pesticides and the results will contributed to the environmental risk assessment of endosulfan sulfate in zebrafish.