Neurotoxicological effects of venlafaxine on Caenorhabditis elegans and Danio rerio

The growing consumption of psychoactive drugs, such as Venlafaxine (VFX), can negatively affect the organisms. Our main hypothesis is to investigate if VFX at human-used doses could exert effects on the behavioral, nervous, and antioxidant systems of two different organisms, zebrafish and C. elegans. We evaluated the effect of acute exposure to VFX at four concentrations (0, 37.5, 75, and 150 mg L-1) using toxicological indicator assessments. We evaluated zebrafish behavior using the novel tank test (NTT), social preference test (SPT), cortisol levels, acetylcholinesterase (AChE) activity, and antioxidant system. In C. elegans, we evaluated body bends, defecation cycles, pharyngeal pumping, AChE activity, and antioxidant system. C. elegans do not show alterations in the behavior analysis of pharyngeal pumping and body bends. Instead, the defecation cycle was increased in the highest dose of VFX. AChE activity also does not have differences compared to the control, the same occurs in lipid peroxidation rates. These results showed that nematodes were more resistant to changes when exposed to VFX. Zebrafish exposed to VFX showed changes in the NTT and SPT test, mainly in the anxiolytic pattern, suggesting that VFX alters this anxiolytic-like behavior. Comparing both organisms, we can observe that zebrafish seems to be more sensitive in this neurotoxicological evaluation.