Ochratoxin A induces locomotor impairment and oxidative imbalance in adult zebrafish.

Ochratoxin A (OTA) is a mycotoxin produced by species of filamentous fungi widely found as a contaminant in food and with high toxic potential. Studies have shown that this toxin causes kidney and liver damage; however, data on the central nervous system effects of exposure to OTA are still scarce. Thus, this study aimed to investigate the effects of exposure to OTA on behavioral and neurochemical parameters in adult zebrafish. The animals were treated with different doses of OTA (1.38, 2.77, and 5.53 mg/kg) with intraperitoneal injections and submitted to behavioral evaluations in the open tank and social interaction tests. Subsequently, they were euthanized, and the brains were used to assess markers associated with oxidative status. In the open tank test, OTA altered distance traveled, absolute turn angle, mean speed, and freezing time. However, no significant effects were observed in the social interaction test. Moreover, OTA also increased glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione reductase (GR) levels and decreased non-protein thiols (NPSH) levels in the zebrafish brain. This study showed that OTA can affect behavior and neurochemical levels in zebrafish.

Propiconazole induces abnormal behavior and oxidative stress in zebrafish.

The use of pesticides has been growing along with the demand for agricultural products. These compounds, however, are not restricted to the field, spreading easily through the soil, contaminating groundwater and reaching urban centers. Propiconazole is a triazole fungicide that has been increasingly used in agriculture. However, there are few data about its effects on non-target organisms. This study aimed to evaluate the effects of propiconazole in zebrafish. The animals were exposed for 96 h to different concentrations of propiconazole (425, 850, 1700, 8500 ng/L), then submitted to the novel tank test for behavioral analyses. The brains were collected for evaluation of oxidative stress parameters. Exposure to propiconazole (1700 and 8500 ng/L) decreased the number of crossings, entries, and time spent in the top, and increased the time spent in the bottom area of the tank. We also observed an increase in the activities of superoxide dismutase and catalase in zebrafish brain exposed to propiconazole at 425, 850, and 1700 ng/L. We conclude that propiconazole alters normal fish behavior and disrupts oxidative status. More studies are necessary to elucidate the exact mechanism underlying the effects of propiconazole on non-target-organisms.