Multiparameters for integrated toxicity assessment of 2,4-D herbicide (dichlorophenoxyacetic acid and dimethylamine salt) in zebrafish (Danio rerio)

• Grant number: 20/07363-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: June 01, 2023
• End date: December 31, 2025
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal Investigator: Lilian Cristina Pereira
• Grantee: Cristina Viriato de Freitas
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated scholarship(s): 24/01989-0 - Assessment of the toxicity of the herbicide 2,4-D (dichlorophenoxyacetic acid and dimethylamine salt) in zebrafish (Danio rerio) embryos: bioenergetic, behavioral and metabolomics analysis, BE.EP.DR

Abstract

2,4-D is one of the most widely used herbicides in the world in agriculture, despite its classification as "possibly carcinogenic to humans". Some of its components in commercial formulas have high lipophilicity, resistance to degradation and bioaccumulative potential, being classified as persistent organic pollutant (POP) due to its high levels in the environment (air, water and sediments), biota and humans. It remains unknown which of the components of 2,4-D is directly cytotoxic, and what is its mechanism of cytotoxic action. In this context, the objective of this study is to elucidate the mechanisms of toxicity of the components of the herbicide 2,4-D (DMA) (2,4-dichlorophenoxyacetic acid and dimethylamine salt) individually and also of a mixture mimicking the composition of the commercial product, using zebrafish as a model organism, which will be monitored from the embryo-larval phase, until the adult phase. Specific objectives of the project are: 1) to assess lethality (CL50), subletality (EC50) and teratogenicity (IT = CL50 / CE50) and other damage to zebrafish embryonic and larval development, 2) to assess acute and chronic damage to reproductive organs male, liver and central nervous system, adult zebrafish, 3) To analyze the influence of parental exposure on the offspring of zebrafish embryos, biochemical biomarkers of neurotoxicity and oxidative stress. Additionally, using explants (in vitro cultivation) as a tool to understand the pathophysiological mechanisms induced in zebrafish organs. The present project aims to carry out an integrated approach to the toxicity induced by components of the herbicide 2,4-D (DMA), providing subsidies for decision making in relation to its use, and useful in establishing safety standards for these compounds, with a view to human health and the conservation of aquatic communities.