de Farias_2019_Comp.Biochem.Physiol.C.Toxicol.Pharmacol_215_1

Fluoxetine (FLX) is a selective serotonin reuptake inhibitor (SSRI) antidepressant widely used in clinics and very often found in environmental samples of urban aquatic ecosystems in concentrations ranging from ng/L to mug/L. Fish populations might be especially susceptible to FLX due to the presence of conserved cellular receptors of serotonin. Neurotoxic effects on fish biota of polluted water bodies may be expected, but there are no sufficient studies in the current literature to elucidate this hypothesis. Batteries of embryo larval assays with zebrafish were performed to evaluate the potential effects of FLX exposure, including environmentally relevant concentrations. Evaluated parameters included survival, development, behaviour and neuronal biochemical markers. Regarding acute toxicity, a 168h-LC50 value of 1.18mg/L was obtained. Moreover, hatching delay and loss of equilibrium were observed, but at a concentration level much higher than FLX measured environmental concentrations (>100mug/L). On the other hand, effects on locomotor and acetylcholinesterase activity (>/=0.88 and 6mug/L, respectively) were found at levels close to the maximum reported FLX concentration in surface waters. Altogether, these results suggest that FLX is neurotoxic to early life stages of zebrafish, in a short period of time causing changes in important ecological attributes which can probably be linked from molecular to population level.