| Environmental endocrine disruptors chemicals(EEDCs) are globally paid attention to since they exist extensively in the environment, and disturb the endocrine system of animals and humans, affecting the body’s normal reproductive, immune,nervous and other functions. Bisphenol A(BPA), a plastic monomer and plasticizer is a well-known endocrine disrupter, widely used in coating, feeder-bottle, tableware,medical instruments and food packing. Triclosan(TCS), a antifungal agent and broad-spectrum antibacterial, is extensive used in variety of personal care and industrial products, including hand soap, detergent, deodorant, toothpaste, and household goods. In recent years, BPA and TCS as the two kinds of environmental endocrine disruptors chemicals are frequently detected in various environmental media, organisms, even the human body, and this will have a negative impact on the environment and human health. and in vivo. So it is of important practical significance to study the toxicological effects of BPA and TCS on the aquatic animals.1. In this work, we investigated the oxidative stress responses to the liver and brain of the zebrafish by examing the oxidative stress indices and antioxidant parameters. Zebrafish were exposed to a range of TCS concentrations(50, 100 or 150μg/L) for 30 days. Increased production of lipid peroxidation(LPO) and protein carbonyl(PC) were detected in the zebrafish due to the chemicals exposure, and significant differences(p< 0.05) were obtained between the control group and 150μg/L groups, indicating that the organism was damaged by oxidative damage due to the increase of reactive oxygen species. The results showed that the content of total glutathione(TG), reduced glutathione(GSH) and oxidized glutathione(GSSG), and the activity of several antioxidant enzymes including superoxide dismutase(SOD),catalase(CAT), glutathione reductase(GR), and glutathione peroxidase(GPx) in the liver or the brain of the zebrafish, were all inhibited after exposure to TCS, showing the occurrence of oxidative stress. Moreover, the activity of true choline esterase(TChE) in the brain of zebrafish was slightly reduced after exposure to TCS,indicating that the oxidative damage and functional abnormality of the zebrafish braincould be caused by TCS. So the study can be inferred that TCS in aquatic systems could affect antioxidant responses in the zebrafish.2. In this work, we investigated the biochemical mechanism involved in the chronic neurotoxicity of low dose(10 μg/L) of BPA for 45 days on brain of male zebrafish by using the iTRAQ-based proteomics. An isobaric Tags for Relative and Absolute Quantitation(iTRAQ) approach coupled with nano high-performance liquid chromatography-tandem mass spectrometry(nano HPLC-MS/MS) analysis was employed to detect and identify the differential expressed proteins. A total of 46 proteins were successfully identified, including 44 up-regulated proteins and 2down-regulated proteins upon BPA exposure. Gene ontology(GO) categories enrichment analysis for the identified proteins showed BPA was able to induce changes in ATP biosynthetic and metabolic process, transmembrane transport and binding(nucleotide, ion, protein). The study also found that BPA induced energy associated proteins, a dysfuction of cytoskeleton assembly, and a concomitant interference with ion binding based on KEGG enrichment analysis. In addition, it could cause the neurotoxicity and dysfunction of the central nervous system following long-term exposure. Therefore, the study found that even the low dose of BPA could have toxic effects on the brain of zebrafish, including the nervous system, energy metabolism, cytoskeleton, ion channel. |
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