Selective effects of carbamate pesticides on rat neuronal nicotinic acetylcholine receptors and rat brain acetylcholinesterase

Smulders, Chantal; Bueters, Tjerk; Kleef, Regina G.D.M. van; Vijverberg, Henk P.M.

doi:10.1016/j.taap.2003.07.011

Cited by 94 publications

(46 citation statements)

References 34 publications

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“…Thus, the obtained K I and k 3 values for malathion and its inhibiting by-products are in accordance with the allosteric effects noticed between the top and the bottom of the gorge [22,33,34]. The progressive development of irreversible inhibition is consistent with the hypothesis that these compounds react with the enzyme to yield a phosphorylated enzyme derivative.…”

Section: Inhibition (%) [Concentration Of Inhibitor (M)]supporting

confidence: 85%

Inhibition of AChE by malathion and some structurally similar compounds

Krstić

Čolović

Kralj

et al. 2008

Journal of Enzyme Inhibition and Medicinal Chemistry

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Inhibition of bovine erythrocyte acetylcholinesterase (free and immobilized on controlled pore glass) by separate and simultaneous exposure to malathion and malathion transformation products which are generally formed during storage or through natural or photochemical degradation was investigated. Increasing concentrations of malathion, its oxidation product malaoxon, and its isomerisation product isomalathion inhibited free and immobilized AChE in a concentration-dependent manner. K I , the dissociation constant for the initial reversible enzyme inhibitor-complex, and k 3 , the first order rate constant for the conversion of the reversible complex into the irreversibly inhibited enzyme, were determined from the progressive development of inhibition produced by reaction of native AChE with malathion, malaoxon and isomalathion. .2) £ 10 26 M, were obtained from the inhibition curves induced by malathion, malaoxon and isomalathion, respectively. However, the products formed due to photoinduced degradation, phosphorodithioic O,O,S-trimethyl ester and O,O-dimethyl thiophosphate, did not noticeably affect enzymatic activity, while diethyl maleate inhibited AChE activity at concentrations . 10 mM. Inhibition of acetylcholinesterase increased with the time of exposure to malathion and its inhibiting by-products within the interval from 0 to 5 minutes. Through simultaneous exposure of the enzyme to malaoxon and isomalathion, an additive effect was achieved for lower concentrations of the inhibitors (in the presence of malaoxon/isomalathion at concentrations 2 £ 10 27 M/2 £ 10 27 M, 2 £ 10 27 M/3 £ 10 27 M and 2 £ 10 27 M/4.5 £ 10 27 M), while an antagonistic effect was obtained for all higher concentrations of inhibitors. The presence of a non-inhibitory degradation product (phosphorodithioic O,O,S-trimethyl ester) did not affect the inhibition efficiencies of the malathion by-products, malaoxon and isomalathion.

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Section: Inhibition (%) [Concentration Of Inhibitor (M)]supporting

confidence: 85%

Inhibition of AChE by malathion and some structurally similar compounds

Krstić

Čolović

Kralj

et al. 2008

Journal of Enzyme Inhibition and Medicinal Chemistry

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“…Anti-cholinesterase pesticides mainly include organophosphates such as malathion as well as carbamates such as carbofuran and carbosulfan. The acute toxicity of these pesticides has been well documented (de Silva et al 1992;Gupta 1994;Smulders et al 2003;Raheja and Gill 2007;Lasram et al 2009Lasram et al , 2014a. Liver, which is the main organ responsible for metabolism, is a common target of pesticide toxicity (Celik et al 2009).…”

Section: Carbosulfan-induced Oxidative Damage Following Subchronic Exmentioning

confidence: 99%

Carbosulfan-induced oxidative damage following subchronic exposure and the protective effects of N-acetylcysteine in rats

Dhouib¹,

Annabi²,

Jrad³

et al. 2015

gpb

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Abstract. Carbosulfan (CB)-induced oxidative stress leads to the inevitable accumulation of free radicals and eventual alteration of antioxidant enzymes in various biological systems. The present study is designed to investigate the preventive effect of N-acetylcysteine (NAC) on carbosulfaninduced hepatic and renal dysfunction in rats. Rats exposed to CB and NAC were examined for toxicity by assessing various biochemical alteration and stress markers including in liver and kidney. Significant increases of blood alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma glutamyltransferase (GGT), creatinine and urea were detected in CB-treated rats. In addition, the levels of antioxidative enzymes such as catalase (CAT), superoxide dismutase (SOD) and reduced glutathione (GSH) also were assessed. According to the results, rats exposed to carbosulfan showed a significant increase in the accumulation of stress markers and an alteration in the antioxidative enzymes activity, when compared to their respective controls. Interestingly, administration of NAC to CB-treated rats attenuates the toxicity of this compound, objectified by biochemical and oxidative improvement of liver and kidney. Thus, the present study reports for the first time that NAC could be a promising therapeutic agent against CB-induced oxidative stress.

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“…The ester bond between N-methylcarbamic acid and 1-naphthol is responsible for carbaryl toxicity. Carbamates are competitive inhibitors of neuronal nicotinic acetylcholine receptors and acetylcholinesterase (28). N-Nitrosocarbamates and the 1-naphthol that they generate are potent mutagens and are more toxic and recalcitrant than carbaryl itself (8,22,26,27,32).…”

mentioning

confidence: 99%

Metabolism of Carbaryl via 1,2-Dihydroxynaphthalene by Soil Isolates Pseudomonas sp. Strains C4, C5, and C6

Swetha

Phale

2005

Appl Environ Microbiol

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Pseudomonas sp. strains C4, C5, and C6 utilize carbaryl as the sole source of carbon and energy. Identification of 1-naphthol, salicylate, and gentisate in the spent media; whole-cell O 2 uptake on 1-naphthol, 1,2-dihydroxynaphthalene, salicylaldehyde, salicylate, and gentisate; and detection of key enzymes, viz, carbaryl hydrolase, 1-naphthol hydroxylase, 1,2-dihydroxynaphthalene dioxygenase, and gentisate dioxygenase, in the cell extract suggest that carbaryl is metabolized via 1-naphthol, 1,2-dihydroxynaphthalene, and gentisate. Here, we demonstrate 1-naphthol hydroxylase and 1,2-dihydroxynaphthalene dioxygenase activities in the cell extracts of carbaryl-grown cells. 1-Naphthol hydroxylase is present in the membrane-free cytosolic fraction, requires NAD(P)H and flavin adenine dinucleotide, and has optimum activity in the pH range 7.5 to 8.0. Carbaryl-degrading enzymes are inducible, and maximum induction was observed with carbaryl. Based on these results, the proposed metabolic pathway is carbaryl 3 1-naphthol 3 1,2-dihydroxynaphthalene 3 salicylaldehyde 3 salicylate 3 gentisate 3 maleylpyruvate.Carbamate insecticides, such as carbaryl (1-naphthyl-Nmethylcarbamate), are highly toxic, have a wide range of activity, and comprise a major portion of pesticides used in the agriculture industry. Widespread and repeated use leads to pollution of soil and groundwater (5). The ester bond between N-methylcarbamic acid and 1-naphthol is responsible for carbaryl toxicity. Carbamates are competitive inhibitors of neuronal nicotinic acetylcholine receptors and acetylcholinesterase (28). N-Nitrosocarbamates and the 1-naphthol that they generate are potent mutagens and are more toxic and recalcitrant than carbaryl itself (8,22,26,27,32). Carbamate pesticides generally do not persist in the environment for a long time. In aqueous solutions, carbaryl hydrolyzes to 1-naphthol, methylamine, and CO 2 (30). Bacteria capable of degrading carbamate pesticides have been isolated from the soil (3,6,7,13,16,25). The first step in degradation is the hydrolysis of carbaryl to 1-naphthol by carbaryl hydrolase, which has been purified and characterized from various organisms (3,5,10,11,20,24). Depending on the strain, 1-naphthol is metabolized via salicylate to either gentisate or catechol (4,7,9,16,17). It has been proposed that prior to ring cleavage, 1-naphthol is hydroxylated either to 4-hydroxy-1-tetralone (1), 3,4-dihydro-dihydroxy-1(2H)-naphthalenone (31), or 1,4-naphthoquinone (25). Though 1-naphthol, salicylate, and gentisate are well-established intermediates in carbaryl degradation, the steps and enzymes responsible for the conversion of 1-naphthol to salicylate have not been demonstrated so far.In this study, we report isolation of three soil bacterium Pseudomonas sp. strains, C4, C5, and C6, utilizing carbaryl as the carbon source via 1-naphthol, salicylate, and gentisate. The aim of this study is to investigate the catabolic pathway and its regulation, with emphasis on the enzymes involved in the conversion of 1-naphthol to ...

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Selective effects of carbamate pesticides on rat neuronal nicotinic acetylcholine receptors and rat brain acetylcholinesterase

Cited by 94 publications

References 34 publications

Inhibition of AChE by malathion and some structurally similar compounds

Inhibition of AChE by malathion and some structurally similar compounds

Carbosulfan-induced oxidative damage following subchronic exposure and the protective effects of N-acetylcysteine in rats

Metabolism of Carbaryl via 1,2-Dihydroxynaphthalene by Soil Isolates Pseudomonas sp. Strains C4, C5, and C6

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