Sodium Selenite Prevents Paraquat-Induced Neurotoxicity in Zebrafish

Considering the antioxidant properties of sodium selenite (NaSeO) and the involvement of oxidative stress events in paraquat-induced neurotoxicity, this study investigated the protective effect of dietary NaSeO on biochemical and behavioral parameters of zebrafish exposed to paraquat (PQ). Fish were pretreated with a NaSeO diet for 21 days and then PQ (20 mg/kg) was administered intraperitoneally with six injections for 16 days. In the novel tank test, the NaSeO diet prevented the locomotor impairments, as well as the increase in the time spent in the top area of the tank, and the exacerbation of freezing episodes. In the preference for conspecifics and in the mirror-induced aggression (MIA) tasks, NaSeO prevented the increase in the latency to enter the area closer to conspecifics and the agonistic behavior of PQ-treated animals, respectively. NaSeO prevented the increase of carbonylated protein (CP), reactive oxygen species (ROS), and nitrite/nitrate (NOx) levels, as well as the decrease in non-protein thiols (NPSH) levels. Regarding the antioxidant enzymatic defenses, NaSeO prevented the increase in catalase (CAT) and glutathione peroxidase (GPx) activities caused by PQ. Altogether, dietary NaSeO improves behavioral and biochemical function impaired by PQ treatment in zebrafish, by modulating not only redox parameters, but also anxiety- and aggressive-like phenotypes in zebrafish.