Antioxidant enzyme activity and oxidative stress in Pomacea canaliculata (Mollusca: Gastropoda) exposed to cypermethrin

LAVARÍAS S; AMBROSIO E; ASTIZ M; ARRIGHETTI F; GARDA HA; RODRIGUES CAPÍTULO A

Buenos Aires

Congreso; SETAC Latin American 11th Biennial Meeting; 2015

SETAC

Several agrochemicals extensively used to control pests in agricultural practices could affect non-target fauna. Most pesticides are lipophilic and passively absorbed through lipid membranes. The effect of these compounds in organisms depends on their susceptibility to biotransformation. In certain organisms, pesticides could alter reactions in aerobic oxidative metabolic pathways causing oxidative stress, condition that leads to protein degradation and enzyme inactivation, lipid peroxidation, damage of nucleic acids and finally cell death. In Argentina, the pyrethroid cypermethrin (CYP) is widely used in agricultural activities. In order to determine metabolic disorders that could be used as biomarkers of pollution, the native freshwater snail Pomacea canaliculata was selected for the present study. Adult males and females of snails were exposed to sublethal CYP concentrations (10, 25 and 100 μg /L) for 1, 4, 7 and 14 days and a biodepuration assay was also performed. The activities of the enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) and the levels of lipid peroxidation (LPO) and protein oxidation (PO) in digestive gland and gills were assessed. In digestive gland, CYP caused a significant increase in the antioxidant enzymes SOD, CAT and GST activity compared to the control group (p< 0.05). Also, LPO and PO levels were affected by CYP treatment (p< 0.05). Biodepuration treatment showed significant differences (p< 0.05) in some biomarkers respect to controls, mainly LPO levels in digestive gland. In most cases, gills did not show significant differences in the biomarkers analyzed in exposed snails to CYP compared to controls. In general, only few treatments showed significant differences (p< 0.05) between males and females of P. canaliculata. Complementary histological studies in snail exposed to CYP were carried out showing histopathological damage in these same tissues. The results of this study indicate that oxidative stress status in P. canaliculata, especially in digestive gland, are significantly affected by CYP probably due to this organ has been characterized as the main site for toxicant metabolism in molluscs. Therefore, these biomarkers could be proposed to monitor pyrethroid pollution in freshwater environments.