RESUMO
The use of toxic pesticides has become a world problem because they can contaminate streams and rivers, producing an adverse impact on non-target aquatic biota, including fishes. Cypermethrin is one of the most important insecticides to control ectoparasites in wide-scale. The aim of this study was to evaluate the effect of commercial formulations of cypermethrin, SHERPA O (0.0, 0.075, 0.15, and 0.3 µg/L of cypermethrin) in fish Prochilodus lineatus for 96 h in semi-static condition, using biomarkers of genotoxicity: micronucleus frequency (MNF) in erythrocytes and biomarkers of oxidative damage: lipid peroxidation (TBARS) and antioxidant defenses, catalase (CAT) and glutathione (GSH) in liver tissue. Our results showed a significant decrease (p < 0.05) of CAT at pesticide concentrations of 0.150 and 0.300 µg/L, but no significant difference was observed in TBARS or GSH in any exposed group (p > 0.05) in comparison to the control. A significant increase was observed in the MNF in the group exposed to 0.3 µg/L of cypermethrin compared to negative control (p < 0.05). Finally, P. lineatus proved to be a sensitive species to the commercial formulations of cypermethrin and that CAT and MNF are effective indicators of these toxic effects.
Assuntos
Inseticidas/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Piretrinas/toxicidade , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Caraciformes , Relação Dose-Resposta a Droga , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Glutationa/metabolismo , Inseticidas/administração & dosagem , Testes para Micronúcleos , Piretrinas/administração & dosagemRESUMO
Prochilodus lineatus, a fish, was exposed to sublethal concentrations of cypermethrin: 0.075, 0.150, and 0.300 µg L(-1) and a control group (without cypermethrin) for 96 h. Five specimens were exposed in each concentration for triplicate (n = 60). Hepatic biochemical values and behavioral changes were studied. The results revealed a significantly higher level of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase in hepatic tissue at different concentrations of cypermethrin tested compared to control (p < 0.05). A decrease in total protein was observed in exposed groups but not significantly (p > 0.05). This study provides information to know toxic mechanisms of cypermethrin on hepatic enzymes of P. lineatus that are poorly understood.
Assuntos
Inseticidas/toxicidade , Fígado/enzimologia , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Alanina Transaminase/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Caraciformes , Fígado/efeitos dos fármacosRESUMO
Biocides are periodically applied in agricultural activities, reaching aquatic systems and acting upon the biota. Amphipods are widely used in toxicity tests because of their sensitivity to a wide range of pollutants. In this work, we report the differential lethality of a widely used pesticide, endosulfan, on the amphipod Hyalella curvispina at two life stages and in three different adult groups, males and females separated by sex and both sexes grouped together. In addition, oxygen consumption of adult groups was determined as a way to estimate the role of behavioral activities and exposure to endosulfan in metabolism shifts. There were no differences between the LC(50) of juveniles and the adults when they were separated by sex (p>0.05). Nevertheless, the LC(50) of adults without sexual differentiation was significantly lower than the LC(50) of juveniles and adults separated by sex (p<0.05). The oxygen consumption rate was higher when adults were grouped without sexual differentiation in the control group. The exposure to low concentrations of endosulfan causes an increase in oxygen consumption in all the treatments. The sexual behavior increased the metabolism and the sensitivity to endosulfan. In future evaluations, adults grouped without sexual differentiation, which were the most sensitive group, should be included in order to mimic the environmental conditions. Using only juveniles or adults separated by sex in toxicity tests may inaccurately estimate the lethality of biocides, especially in species with constant reproductive activities.
Assuntos
Anfípodes/efeitos dos fármacos , Endossulfano/toxicidade , Poluentes Químicos da Água/toxicidade , Anfípodes/metabolismo , Animais , Metabolismo Energético/efeitos dos fármacos , Feminino , Dose Letal Mediana , Masculino , Consumo de Oxigênio/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Comportamento Sexual Animal/efeitos dos fármacos , Testes de ToxicidadeRESUMO
Toxicants on fish may induce genetic alterations that can be used as genotoxic markers. We evaluated DNA damage using alkaline comet assay applied on erythrocytes after in vivo exposure of Prochilodus lineatus to different concentrations of Cypermethrin (0.300, 0.150, 0.075 and 0.000 microg/L) as a probable chemical mutagen. The results revealed a significantly higher level of DNA damage at all concentrations of Cypermethrin tested compared to control and background level (p < 0.05). We have standardized the technique for one of the most common native fish species that will be useful for biomonitoring genotoxicity in polluted waters of the region.
Assuntos
Ensaio Cometa/métodos , Peixes/genética , Inseticidas/toxicidade , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Álcalis , Animais , Dano ao DNA , Monitoramento AmbientalRESUMO
Freshwater fish Prochilodus lineatus were exposed to sublethal concentrations of cypermethrin (0.3 and 0.6 microg/l) for 2, 5 and 8 days. It was observed that with the increase of exposure time total erythrocyte (RBC), hemoglobin (Hb), hematocrit (Ht) and mean corpuscular hemoglobin concentration (MCHC) values decreased but mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) values increased. These reports indicate that hematological parameters, may be useful as a diagnostic test for cypermethrin exposure in aquatic organisms.