Chlorpyrifos-Based Insecticides Induced Genotoxic and Cytotoxic Effects in the Ten Spotted Live-Bearer Fish, Cnesterodon decemmaculatus (Jenyns, 1842)

摘要

Mortality, genotoxicity, and cytotoxicity of the 48% chlorpyrifos (CPF)-based formulations Lorsban~* 48E~® and CPF Zamba~® were evaluated on Cnesterodon decemmaculatus (Jenyns, 1842) (Pisces, Poeciliidae) under laboratory conditions. Induction of micronucleus (MN) and alterations in the erythrocyte/erythroblast frequencies were employed as end points for genotoxicity and cytotoxicity, respectively. For Lorsban~* 48E~®, mean values of 0.13 and 0.03 mg/L were determined for LC_(50) at 24 and 96 h, respectively, and these concentrations reached mean values of 0.40 and 0.21 mg/L for CPF Zamba~®. Mortality values increased as a positive linear function of the CPF Zamba~® concentrations, but not for Lorsban~* 48E~® concentrations. There was no significant relationship between mortality and exposure time within the 0-96 h period for both formulations. LC_(50) values indicated that the fish were seven fold more sensitive to Lorsban~* 48E~® than to CPF Zamba~®. Lorsban~* 48E~® within the concentration range of 0.008-0.025 mg/L increased MN frequency at both 48 and 96 h of treatment. Similar results were also observed when fish were exposed to 0.052-0.155 mg/L of CPF Zamba~®, regardless of the exposure time. Cellular cytotoxicity was found after Lorsban~* 48E~® and CPF Zamba~® treatments for all concentrations and time exposures, estimated by a decrease in the frequency of mature erythrocytes and a concomitant enhanced frequency of erythroblasts in circulating blood. Furthermore, our results demonstrated that Lorsban~* 48E~® and CPF Zamba~® should be considered as CPF-based commercial formulations with marked genotoxic and cytotoxic properties.