Avaliação ecotoxicológica de 17 β-estradiol por meio de parâmetros genéticos utilizando como modelo experimental Oreochromis niloticus

• Autor(a) principal: Sponchiado, Graziela
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório do Centro Universitário Braz Cubas
• Texto Completo: https://repositorio.cruzeirodosul.edu.br/handle/123456789/2350
• topic: Toxicologia – Aspectos ambientais; CNPQ::CIENCIAS BIOLOGICAS; CNPQ::ENGENHARIAS::ENGENHARIA SANITARIA

A significant quantity of human and veterinary medicines was excreted by urine and excrement, in their original structures or as their metabolites. Most of these drugs are not completely biodegraded, and due their partial removal during Waste Water Treatment (WWT) and. Water Treatment (WT), these contaminants can be detected in aquatic systems. Despite of very low levels being reported in surface water, groundwater and some drinking water, that may not show significant effects in the environment for acute toxicity, much more should be known about the potential for chronic effects of pharmaceuticals in low levels. The acute and chronic genotoxic effects of 17 β-estradiol (E2) were evaluated in Oreochromis niloticus (Family: Cichlidae) using the micronucleus test, nuclear abnormalities evaluation and comet assay, for fishes exposed to 6 ng.L-1 of E2 for 24 hours, 48 hours and 10 days. The results showed that E2 have genotoxic effect on blood cells because there was lower micronucleus frequencies in the test group in relation to the control group (without E2 treatment) for 10 days exposure (p=0.036). Differences were also observed for nuclear abnormalities at 24 h exposure, which were higher for the test group (p=0.018). The comet assay demonstrated genotoxic effects of E2 after 48 h of contact, when compared to the negative control (p<0.001) The results suggest that the tested concentration of the E2 probably gave rise to acute and chronic genotoxic and mutagenic disturbances in the erythrocytes of O. niloticus. The combination of micronucleus, nuclear abnormalities and comet assay proved to be suitable and useful in the evaluation of the genotoxicity of E2. However, further studies must be carried out to elucidate its clastogenic and aneugenic effects.