Effectiveness of L-arginine or nitric oxide as a reactivator and an antidote against cholinesterase pesticides and other toxic substances

Elitsa T. Dencheva, Radoy I. Ivanov

Abstract: The cholinergic system is one of the most important neuromediator systems in organisms that manage physiological functions, biology, behavior, adaptation, intellect. Cholinesterases (AChЕ and BChE) occupy an important place in the structure of this system. AChЕ participates in the mechanisms of synaptic conduction, while BChE mainly hydrolyses many toxic products that damage the nervous system. The main objective of this study was to establish the levels of stimulation on the activity of cholinesterases by some donors of nitric oxide (for example L-arginine) and to estimate the role of nitric oxide (NO) as a mediator that controls the activity of these enzymes. Another objective of the study to obtain data useful in biomonitoring assessment of ecotoxicology environment and creation of new approaches for prevention and therapy against specific intoxicants and pesticides. The main finding of the study is the revealed significant activation of cholinesterases from L-arginine (10-50 mM) in various brain structures in mammals (Rattus rattus and Oryctolagus cuniculus) and in invertebrate fractions from Vespula germanica and Apis mellifera. This stimulation is better demonstrated for BChE, which can reach eight times in magnitude; L-arginine, as donor of NO, plays an importante role as a protector and reactivator of the inhibited activity of cholinesterases and as an antidote for severe intoxications from pesticides and other toxic products, including cyanides; the application of a broad spectrum NO synthases inhibitor (L-NMMA) removes partially or fully activates the activity of cholinesterase in fractions of vertebrates and invertebrates with added toxins. This means that NO is an important factor in the control of cholinesterase activity.

Keywords: antidote; cholinesterase activity; ecotoxicology; L-arginine; L-NMMA; nitric oxide; pesticides

Date published: 2018-12-28