Study of biochemical variations and genotoxicity induced by the mixture of contaminants in tilapia (Oreochromis niloticus), as biomarkers of environmental contamination.

Abstract

Currently the aquatic biota is subject to a wide mix of xenobiotic compounds that are discarded in the environment. These compounds, produced in large-scale consumption of modern society, may have high potential cytotoxic, mutagenic and carcinogenic. In this context stand pesticides, polycyclic aromatic hydrocarbons (PAHs), estrogen disruptors and heavy metals.Biomonitoring studies in aquatic organisms are very promising, and fish as sentinels to show extremely sensitive to environmental disturbances caused by anthropogenic activities. This study aims to evaluate in Oreochromis niloticus, biochemical responses after controlled exposure to mixtures of organophosphate and pyrethroid pesticides, benzo (a) pyrene (PAH) and 17²-estradiol (an endocrine disruptor). Will be analyzed after 5 days of treatment, brain, liver and gills, the activity of the enzyme acetylcholinesterase, carboxylesterase, glutathione S-transferase, UDP-glicurosiltransferase, EROD, BROD, PROD, and levels of DNA damage (8-oxodGuo), lipid peroxidation and metallothioneins, and the presence of micronuclei in erythrocytes, intending thereby a better understanding of the interaction of the effects of contaminants on fish health. Finally, a detailed study of biomonitoring along the river Tiet /SP, on Araçatuba city. They will be examined biomarkers in fish exposed to water from different parts of the river in a region with intense sulcro-ethanol, livestock and several condominiums with nautical leisure activities on the river. This is an attempt to evaluate the possible effects of human activities on water quality in the region.