Toxicometabolomics of lindane in adult zebrafish (Danio rerio) using GC-MS/MS and LC-Orbitrap-MS/MS

Abstract

Lindane is a broad-spectrum persistent organochlorine pesticide that has been used to control pests for many years. In this study, its toxic mechanisms in adult zebrafish were investigated using targeted metabolomics with GC-MS/MS and non-targeted metabolomics with LC-Orbitrap-MS/MS. Zebrafish was exposed to lindane in water for 48h in three groups: control, low exposure (1/10 LC50) and high exposure (LC50). In the zebrafish exposed to low concentration of lindane, 2.24–3.98mg/kg of lindane were determined, while 35.67–56.46mg/kg were observed in the zebrafish exposed to high concentration. A total of 118 metabolites were identified from 394 metabolites on GC-MS/MS and 45 metabolites were selected as biomarkers. A total of 62 metabolites were identified on LC-Orbitrap-MS/MS and 7 metabolites were selected as biomarkers. Three groups were well separated on partial least squares-discriminant analysis (PLS-DA), and a total of 52 metabolites in both the targeted and non-targeted metabolites were selected as biomarkers through VIP and ANOVA tests to construct a heatmap. Five metabolic pathways such as the pentose phosphate pathway (PPP), histidine metabolism, phenylalanine metabolism, alanine/aspartate/glutamate metabolism, and phenylalanine/tyrosine/tryptophan biosynthesis, were observed to show toxicologically significant alterations. Oxidative stress was also confirmed through MDA and ROS assays. Such perturbations of the metabolic pathways of zebrafish caused by the exposure to lindane resulted in significant toxicological effects.