Cypermethrin: oxidative stress and genotoxicity in retinal cells of the adult zebrafish

PARAVANI, ENRIQUE; SIMONIELLO, MA. FERNANDA; POLETTA, GISELA L.; FAVIO ZOLESSI; CASCO, VÍCTOR

MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2018 vol. 826 p. 25 - 32

1383-5718

Cypermethrin (Cyp), is widely used for control of indoor and field pests. Is one of the most common contaminants in freshwater aquatic systems. In the present report, we evaluated its possible genotoxic effect and the activation of the superoxide dismutase (SOD) and catalase (CAT) systems in adult zebrafish retinal cells exposed to 0.3 µg/L and 0.6 µg/L Cyp. The comet assay study demonstrated that retinal cells are sensitive to DNA damage after in vitro exposure to hydrogen peroxide (H2O2), showing a dose-dependent response. We also found an increase in DNA damage of retinal cells following a dose and time-dependent treatment with Cyp. Both histological and immunofluorescence techniques show the presence of apoptotic cells in the zebrafish retina after 9 days of treatment with 0.6 µg/L Cyp. Thereby, the histone γ-H2AX, a marker of double strand DNA damage, was immunodetected in both, the outer and inner nuclear layer after exposure to 0.6 µg/L Cyp for 12 days, while caspase-3, an apoptotic marker, was detected in the outer nuclear layer. Also, it was verified that the activities of SOD and CAT were significantly increased after exposure to 0.6 µg/L Cyp both during 6 and 9 days. The same treatment caused a significant up-regulation of the mRNA levels of the sod and cat genes. Taken together, these results strongly indicate that Cyp causes DNA damage and oxidative stress, modifying the activities of the enzymes responsible for maintaining ROS balance, as well as in their corresponding gene expression levels. This pyrethroid also has the potential to induce apoptosis in retinal cells.