Neurotoxicity Assessment of Four Different Pesticides Using In Vitro Enzymatic Inhibition Assays

Abstract

Pesticides affect different organs and tissues according to their bioavailability, chemical properties and further molecular interactions. In animal models exposed to several classes of pesticides, neurotoxic effects have been described, including the reduction of acetylcholinesterase activity in tissue homogenates. However, in homogenates, the reduction in enzymatic activity may also result from lower enzymatic expression and not only from enzymatic inhibition. Thus, in this work, we aimed to investigate the neurotoxic potential of four distinct pesticides: glyphosate (herbicide), imazalil (fungicide), imidacloprid (neonicotinoid insecticide) and lambda-cyhalothrin (pyrethroid insecticide), by assessing their inhibitory effect on the activity of acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase, by using direct in vitro enzymatic inhibition methods. All pesticides dose-dependently inhibited AChE activity, with an inhibition of 11 ± 2% for glyphosate, 48 ± 2% for imidacloprid, 49 ± 3% for imazalil and 50 ± 3% for lambda-cyhalothrin, at 1 mM. Only imazalil inhibited BChE. Imazalil induced dose-dependent inhibition of BChE with identical pattern as that observed for AChE; however, for lower concentrations (up to 500 μM), imazalil showed higher specificity for AChE, and for higher concentrations, the same specificity was found. Imazalil, at 1 mM, inhibited the activity of BChE by 49 ± 1%. None of the pesticides, up to 1 mM, inhibited tyrosinase activity. In conclusion, the herbicide glyphosate shows specificity for AChE but low inhibitory capacity, the insecticides imidacloprid and λ-cyhalothrin present selective AChE inhibition, while the fungicide IMZ is a broad-spectrum cholinesterase inhibitor capable of inhibiting AChE and BChE in an equal manner. Among these pesticides, the insecticides and the fungicide are the ones with higher neurotoxic potential.

Parkinson’s disease and food expenditure in Italy: stochastic and non-stochastic analyses

“…The unexpected causative effect of citrus fruit may be attributed to the widespread use of pesticides, in particular thiabendazole (E233) and imazalil, known for their neurotoxic activity and ability to alter the intestinal microbiota [37,38 ].…”

Acetylcholinesterase activity in forager honey bees of Nepal

“…Enzymatic biomarker Acetylcholinesterase (AChE) is one of the promising enzymes to test the physiological effects of a variety of factors in organisms including bees. Because of its ability to change with a multitude of factors including pesticide exposure (Boily et al, 2013; Martins‐Gomes et al, 2022; Rajagopalan et al, 2023), seasonal conditions (Kim et al, 2017), landscape (Badiou‐Bénéteau et al, 2013), honey bee castes and brood rearing status (Kim et al, 2017, 2019), among others, AChE can also be used as a biomarker for, and to study the bees' responses to, various causative agents such as changing environmental conditions and other stressors. These stressors can be anything that disrupts the day‐to‐day life of an organism such as disruption of habitat, disruption of other resources, changes in micro‐ and macro‐climate, and so forth.…”

Ion-Modified Starch Film Enables Rapid Detection of Spoiled Fruit Juices

“…Existing food safety problems are mainly caused by the following issues: heavy metal contamination in the environment [ 6 ], pesticide and veterinary drug residues [ 7 ], bacteria and biotoxins [ 8 ], additive abuse [ 9 ], and incorrect operations during production and storage. Several techniques have been developed for rapid food detection, including immunoassays [ 10 ], enzyme inhibition [ 11 , 12 ], colorimetric analysis [ 13 , 14 ], and biological techniques [ 15 ]. Although the above techniques have many advantages, they have relatively complex operations and high detection costs; the accuracy of the results is susceptible to environmental influences, leading to the deviation of the test results and making it difficult to achieve simple and accurate real-time detection.…”