Approach to the Effects of Chlorpyrifos on Jenynsia lineata Exposed to Environmentally Relevant Concentrations: Biomarkers of Oxidative Stress, Neurotoxicity and Genotoxicity

LOMBARDERO, LR; MEDICI, S; MENDIETA, J.; VILLAGRAN, D; PÉREZ DJ.,; MENONE, ML

Congreso; SETAC Latin America 15th Biennial Meeting; 2023

Chlorpyrifos (CPF) is a common organophosphate insecticide used for pest control in agriculture and nonagricultural settings, acting as an acetylcholinesterase (AChE) inhibitor. It is highly toxic to aquatic life and can persist in the environment (half- life: 81 days in surface water). The aim of the present study was to evaluate effects of oxidative stress and damage, neurotoxicity and genotoxicity in Jenynsia lineata exposed to environmentally relevant concentrations of CPF during 96 h. Five tanks (30 L) were set up, using females of J. lineata (n=6 per treatment; standard length: 4.31 ± 0.50 cm; total weight: 1.67 ± 0.51 gr), one as a control and four with CPF concentrations of 0.05, 0.5, 5, and 50 μg/L. Liver, gills, and brain were dissected and immediately frozen with liquid nitrogen and stored at -80°C until biomarkers analysis. The blood was extracted and smear were done and fixed with methanol for further analysis. During the course of the experiment, three individuals exposed at 50 ug/L and one exposed at 5 ug/L died at the first 24 hs indicatingthat this concentration is closed to the LC50. While the remaining three individuals exposed at 5o ug/L were euthanized because they looked moribund, and were used for measuring biomarkers. An increase in the activity of the enzymes catalase and glutathione-S-transferase in brain, and of superoxide dismutase in gills was observed at 0.05 μg/L (p0.05), while inhibition of AChE was observed at 0.5 μg/L (29.51%) and 5 μg/L (49.53%) (p0.05). At 50 μg/L, increased activity of CAT in liver and a 77.6% inhibition of AChE was observed (p