Evaluation of cholinesterase inhibition by deltamethrin in different tissues of Ancistrus Multispinnis

Abstract

This study investigated the effects of sublethal deltamethrin exposure on cholinesterase (ChE) enzyme activity in Ancistrus multispinnis, a freshwater fish species. Deltamethrin, a type II pyrethroid insecticide, is widely used in agriculture and has high toxicity to aquatic organisms. Fish were exposed to sublethal doses of 3 and 4 mg/kg deltamethrin for 96 hours. Cholinesterase activity was measured in different tissues, including muscle, brain and gills, using the Ellman colorimetric method. The results showed that deltamethrin did not cause a significant inhibition in cholinesterase activity in any of the tissues analyzed. This suggests that, under the experimental conditions used, deltamethrin does not act as a potent inhibitor of ChE in Ancistrus multispinnis, highlighting an important difference in relation to other neurotoxic pesticides. These findings are important for understanding the mechanisms of deltamethrin toxicity and indicate that other biomarkers must be investigated to fully evaluate the sublethal effects of this pesticide.