Effects of early-life exposure to Venlafaxine in Caenorhabditis elegans

Improper disposal of contaminants in wastewater may adversely impact organisms across multiple biological levels, including exposure to pharmaceutical and personal care products (PPCPs). Venlafaxine (VFX), a frequently prescribed antidepressant, is a drug of concern due to its potential environmental and neurotoxic effects. The concentrations of VFX used in this study were selected to span a range relevant to both acute toxicological testing and higher-end environmental contamination scenarios. Higher concentrations may occur in wastewater effluent, hospital discharge, or pharmaceutical manufacturing waste streams. This study investigated the effects of early-in-life (pre-and neonatal) VFX exposure on Caenorhabditis elegans at concentrations of 0, 9.37, 18.75, 28.12, or 37.5 mg/L. Neurobehavioral and cholinergic endpoints were assessed at the L4 stage to assess long-term neurotoxicity. Data demonstrated that worms exposed to the highest concentration exhibited increased locomotor activity, while pharyngeal pumping was elevated at both 9.37 and 37.5 mg/L. Acetylcholinesterase (AChE) activity was decreased at 9.37 and 28.12 mg/L. Early-life VFX exposure also altered social feeding behavior, with worms showing a preference for bacterial lawn border (18.75 and 37.5 mg/L) and enhanced group feeding (28.12 and 37.5 mg/L). These results indicate that neonatal VFX exposure induces behavioral and neurochemical changes in C. elegans, associated with disruption of the cholinergic system.