040 | Comparative neurotoxicity of glyphosate and its metabolite aminomethylphosphonic acid: evidence from Cyprinus carpio

Serafina Ferrara¹, Jana Blahova², Premysl Mikula², Petr Marsalek², Caterina Faggio^1|3 | ¹Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy; ²Department of Animal Protection and Welfare and Veterinary Public Health, University of Veterinary Sciences Brno, Brno, Czech Republic; ³Department of Eco-sustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Naples, Italy.

Glyphosate (Glp) [N-(phosphonomethyl)glycine] is one of the most widely used herbicides worldwide, valued for its broad-spectrum activity and effectiveness in genetically modified crop systems. Glp binds readily to soil particles and can leach into groundwater or be transported via runoff to surface waters, where it may accumulate in sediments. In the environment, Glp is primarily degraded through microbial activity, producing aminomethylphosphonic acid (AMPA) as its primary metabolite. Consequently, AMPA can persist for extended periods in soils, sediments, and aquatic systems, where it is frequently detected [1]. The persistence of Glp and its metabolites in aquatic environments, coupled with their potential for biomagnification across the food web, raises critical concerns about their impact on non-target aquatic species [2]. This study examined and directly compared neurotoxic effects in common carp (Cyprinus carpio) following a 28-day dietary exposure to two different concentrations of both, Glp (352.2 and 3310.0 µg/kg) and AMPA (335.2 and 3441.0 µg/kg). To gain a comprehensive view of the potential neurotoxic effects, a suite of sensitive biomarkers has been assessed, i.e., acetylcholinesterase activity in the brain and muscles, dopamine concentration in the brain, butyrylcholinesterase activity in plasma, and the modulation of ache gene expression in the gill and brain. The results suggest that dietary exposure to Glp and AMPA can affect cholinergic and dopaminergic pathways in fish, with the brain being a particularly sensitive target organ. Our findings contribute to understanding the potential neurotoxic risks posed by Glp-derived compounds in aquatic environments.