Embryotoxic, teratogenic and genotoxic effect in zebrafish (Danio rerio) by exposure to arsenic

Background. Understanding the toxicity mechanism of arsenic has been hampered by biological, chemical factors, including the dose response ratio, the specificity and sensitivity of species used in bioassays from toxicological studies to understand their toxicodynamics. Goals. The purpose of this study was to evaluate the embryotoxic, teratogenic and genotoxic effect caused by exposure to arsenic, through the frequency analysis of malformations and micronuclei in peripheral blood erythrocytes in zebrafish. Methods. The toxicity curve of arsenic in zebrafish embryos was calculated from exposure to concentrations between 0.0031 and 0.05 mg L-1 of sodium arsenite (NaAsO2) for 72 hours to determine the mean lethal concentration (LC50) for the embryotoxicity and teratogenesis test. For the genotoxicity test, the calculation of the toxicity curve with adult zebrafish that were exposed to concentrations between 0.035 and 0.044 mg L-1 for 48 hours was previously performed in order to establish LC50. Results. The effect of sodium arsenite was shown to be statistically positive for embryotoxicity and teratogenesis tests at the evaluated concentrations. Exposure to sodium arsenite resulted in abnormal embryonic development at each of the test concentrations, in addition to malformations. And a statistically significant increase in the frequency of micronucleated erythrocytes of 0.035, showing genotoxic damage of arsenic. Conclusions. This study showed that the induction of nuclear abnormalities in erythrocytes, as well as abnormalities in embryonic development, are extremely sensitive indicators in the study of toxicological effects, and suggest that the risk potential of this metalloid should be tested in future research.