Evaluación preliminar de biomarcadores enzimáticos en caracoles de agua dulce ( Pachychilus sp.) del humedal “Ciénaga de Tamasopo”, México

Abstract

The activity of the enzymeacetylcholinesterase (AChE), the rate of conjugation of glutathione s-transferase (GST) and the presence of malondialdehyde (MDA), as biomarkers of exposure to pesticides, were determined during two seasons (dry and post-rains) in tissue of aquatic macroinvertebrates (freshwater snails - Pachychilus sp.-) residents of the “Cienega de Tamasopo” wetland (San Luis Potosi, Mexico). This was accompanied by a monitoring of the physicochemical parameters in the water of the wetland with a multiparameter probe. The activity of the biomarkers was determined in the S12 fraction (post-mitochondrial fraction) of tissues of Pachychilus sp. by means of UV-Visible spectrophotometry methods in a microplate reader. We found a lower activity of AChE (39.0%), higher ratio of conjugation of GST (28.5%) followed by a lower presence (25.0%) of lipid peroxidation (MDA) in the dry season in the tissue of the snails. In addition, significant associations were found between the ratio of conjugation of the GST with the rest of the biomarkers in both seasons, which is the result of detoxification processes in the snails. The activity of the biomarkers could be modulated by salinity, thus regulating the production of antioxidant enzymes and the toxicity of the pesticides used in agricultural areas near this wetland. The snails of the genus Pachychilus sp. they can be used as bioindicators of the health status of wetlands, which can lead to the design of management measures for the conservation and sustainable management of these ecosystems.