Comportamento motor como um biomarcador detoxicidade induzida por mancozebe em embriões de peixe-zebra (Danio rerio hamilton-buchanan,1822)

Abstract

The mancozeb fungicide, over the years, has been used in a large scale in the protection of monocultures. The intensive use of pesticides leads to contamination of environmental matrices such as water. Previous studies have demonstrated that mancozeb can exert pro-oxidant effects through the formation of reactive oxygen species. In view of the fact that aquatic organisms are dependent on the redox equilibrium to regulate processes essential to their development, any factor that alters this balance may result in damage to the normal development of these organisms. In this way, the fungicide can cause damage to aquatic ecosystems that are particularly vulnerable to pesticide contamination. In this sense, we seek to evaluate behavioral and biochemical biomarkers against exposure to environmentally relevant concentrations of mancozeb during the embryonic development of zebrafish. Embryos of 4 hours post-fertilization (hpf) were exposed to Mancozebe 96% at concentrations of 5, 10 and 20 μg / L, maintaining a control group. The toxicity of the compound was evaluated by behavioral and biochemical parameters at 24, 72 and 168 hpf. The results showed that mancozeb significantly altered the hatching rate, the spontaneous movement of the embryos (24 hpf), inferred damage to escape motor responses and the swimming capacity (72 hpf), affected the exploratory behavior of the larvae (168 hpf) and was responsible for an increase in the generation of reactive oxygen species also in larvae (72 hpf). Thus, mancozeb, at low concentrations, was able to alter behavioral parameters and cause an increase of reactive oxygen species in zebrafish in embryonic development. We emphasize that the behavioral effects induced by mancozeb occurred at previous exposure times in comparison with biochemical alterations, thus pointing to behavioral analyzes as tools sensitive to the early detection of the effects caused by contamination by agricultural products, since they manifest themselves previously than biochemical parameters.