Avaliação da produção de espécies reativas em células linfomononucleares e do status redox celular em eritrócitos da população circunvizinha a laguna Mundaú (Maceió-AL) exposta a espécies químicas potencialmente tóxicas

Abstract

The Estuarine Lagoon Mundaú-Manguaba Complex (ALAGOAS) provides a large subsidy for the fish trade. In Maceió, the Mundaú lagoon represents a source of income and food for the population. However, the great anthropogenic activity has caused this ecosystem to undergo degradation processes. As a consequence, it releases contaminants that may be harmful to the environment, such as potentially toxic chemical species, which include mercury (Hg), lead (Pb), arsenic (As) and cadmium (Cd). Recent work by our research group has quantified the presence of chemical species in the Mundaú lagoon, highlighting high concentrations of Hg and Pb. We aimed to evaluate the mercury level in the blood and urine of fishermen and correlate it with the level of oxidative stress in blood cells. We show in this study that the fishermen (exposed group) of Mundaú Lagoon (Maceió - Alagoas, Brazil) have higher concentrations of total mercury in blood and urine than the control group. This mercury can influence changes in the redox system, generating reactive oxygen species production, which is linked to several diseases of the metabolic forum, such as type 2 diabetes and hypertension. In this work, fishermen’s lymphomononuclear cells had a high level of reactive oxygen species and we highlight that the erythrocytes showed greater damage to biomolecules, which includes increased lipid peroxidation and protein oxidation and decreased total thiol and alteration of the cell redox state, as well as decreased activity of antioxidant enzymes (SOD, GPx and GST). These alterations in the antioxidant system of the group exposed to the aquatic environment with mercury can contribute to generate oxidative stress, which is also related to impairment in the functional capacity of hemoglobin to bind to oxygen. The oxygen uptake of hemoglobin decreased in the exposed group and the cell membrane showed increased osmotic fragility in relation to the control group, indicating fragility of the membrane. Correlations were found between mercury and oxidative stress. These results suggest that mercury in the blood of fishermen may be responsible for causing damage to the oxidative state of blood cells and in functional capacity of hemoglobin, and strengthens the need for greater environmental monitoring in the waters of CELMM and the possible biological effects caused on the surrounding population.