Multi-tissue metabolic responses of goldfish (Carassius auratus) exposed to glyphosate-based herbicide

Most genetically modified crops are engineered for herbicide tolerance, among them, glyphosate tolerant crops have the greatest share. Glyphosate is one of the most extensively used herbicides worldwide. The popularity of glyphosate stems from its low cost, low environmental impact, and effectiveness while being safe for animals. The toxicity of glyphosate to untargeted organisms was studied using goldfish (Carassius auratus) after exposure to different concentrations of glyphosate isopropylamine salt, a glyphosate based herbicide for 96 hours. Tissues of brain, kidney and liver were collected and subjected to NMR-based metabolomics analysis and histopathological inspection. Plasma was collected and the hematological parameters of glutamic-oxaloacetic transaminase (GOT), glutamate-pyruvate transaminase (GPT), lactate dehydrogenase (LDH), blood urea nitrogen (BUN) and creatinine (CRE) were quantified. Glyphosate produced an increase in the hematological parameters of BUN and CRE and dose-dependent injuries. Metabolomics analysis revealed significant perturbations in neurotransmitter equilibrium, energy metabolism and amino acid metabolism in glyphosate dosed fish, which are associated with the toxicity of glyphosate. The results highlight the vulnerability of glutaminergic neurons to glyphosate and enlighten the potential of glutamine as an early marker of glyphosate induced neurotoxicity.