Evaluation of the deleterious effects of diuron and metabolites in tetra (Astyanax sp): tests of toxicity, oxidative stress markers, genotoxic markers and biotransformation enzymes

Abstract

The application of pesticides in agriculture is a practice widely held to control pests and weeds to obtain high yields in production. The main pesticide currently used in the culture of cane sugar, is the Diuron, a compound of feniluréias that can be toxic to non-target species like fish. The pesticide may be degraded to three other major toxic compounds not yet known. The aim of this study is to perform toxicity tests, genotoxicity and biochemical in lambaris (Astinax sp) after exposure to diuron and its main metabolites, 3 - (3,4-dichlorophenyl)-3-methylurea (DCPMU), the 3.4 -diclorofenilureia (DCPU) and 3,4-dichloroaniline (DCA) in different concentrations and exposure times. The tests of toxicity is determined the concentrations of contaminants from LC1 and LC10 values for exposure times of 2 to 7 days. Genotoxicity testing will be performed with the examination of the comet assay in the blood of animals. It will also be considered biomarkers of contamination in the gills and livers of organisms. This method is based on the analysis of biological response generated in the case, oxidative stress, when the organisms are exposed to chemicals. Will be conducted to analyze the enzymes catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), 7-Etoxiresorufina deetilase-¸-(EROD) and levels of malondialdehyde (MDA) formed by lipid peroxidation, a consequence of oxidative stress. It will be also performed to quantify protein to calculate the enzyme activity. Thus, the realization of this project will allow us to predict whether the degradation of Diuron on the environment can lead to a situation more or less harmful to the organisms exposed.