title: Isatin-3-N4-benzilthiosemicarbazone, a non-toxic thiosemicarbazone derivative, protects and reactivates rat and human cholinesterases inhibited by methamidophos in vitro and in silico.
abstract: Organophosphates (OPs), which are widely used as pesticides, are acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors. The inactivation of AChE results in the accumulation of acetylcholine at cholinergic receptor sites, causing a cholinergic crisis that can lead to death. The classical treatment for OP poisoning is administration of oximes, but these compounds are ineffective in some cases. Here we determined whether the new compound isatin-3-N(4)-benzilthiosemicarbazone (IBTC), which in our previous study proved to be an antioxidant and antiatherogenic molecule, could protect and reactivate AChE and BChE. Toxicity of IBTC after subcutaneous injection in mice was measured using assays for oxidized diclorofluoresceine (DCF), thiobarbituric acid reactive substances (TBARS), non-protein thiol (NPSH) levels, and catalase (CAT), sodium potassium (Na(+)/K(+)) ATPase, delta-aminolevulinic acid dehydratase (ALA-D), and glutathione peroxidases (GPx) enzyme activities. The cytotoxicity was evaluated and the enzymatic activity of cholinesterase was measured in human blood samples. Molecular docking was used to predict the mechanism of IBTC interactions with the AChE active site. We found that IBTC did not increase the amount of DCF-RS or TBARS, did not reduce NPSH levels, and did not increase CAT, (Na(+)/K(+)) ATPase, ALA-D, or GPx activities. IBTC protected and reactivated both AChE and BChE activities. Molecular docking predicted that IBTC is positioned at the peripheral anionic site and in the acyl binding pocket of AChE and can interact with methamidophos, releasing the enzyme's active site. Our results suggest that IBTC, besides being an antioxidant and a promising antiatherogenic agent, is a non-toxic molecule for methamidophos poisoning treatment.
authors.affiliation: Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Campus UFSM, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Rômulo Pillon
authors.initials: RP
authors.lastname: Barcelos
authors.forename: Rafael
authors.initials: R
authors.lastname: de Lima Portella
authors.forename: Thiago Henrique
authors.initials: TH
authors.lastname: Lugokenski
authors.forename: Edovando José Flores
authors.initials: EJ
authors.lastname: da Rosa
authors.forename: Guilherme Pires
authors.initials: GP
authors.lastname: Amaral
authors.forename: Luiz Filipe Machado
authors.initials: LF
authors.lastname: Garcia
authors.forename: Leandro
authors.initials: L
authors.lastname: Bresolin
authors.forename: Vanessa
authors.initials: V
authors.lastname: Carratu
authors.forename: Félix Alexandre Antunes
authors.initials: FA
authors.lastname: Soares
authors.forename: Nilda Berenice
authors.initials: NB
authors.lastname: de Vargas Barbosa
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002800:Cholinesterase Inhibitors / Q000633:toxicity*; D002801:Cholinesterase Reactivators / Q000494:pharmacology*; D002802:Cholinesterases / Q000378:metabolism; D006801:Humans; D007306:Insecticides / Q000633:toxicity*; D007510:Isatin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D008214:Lymphocytes; D008297:Male; D051379:Mice; D062105:Molecular Docking Simulation; D009946:Organothiophosphorus Compounds / Q000633:toxicity*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D002800:Cholinesterase Inhibitors; D002801:Cholinesterase Reactivators; D007306:Insecticides; D009946:Organothiophosphorus Compounds; D007510:Isatin; C014655:methamidophos; D002802:Cholinesterases; D000254:Sodium-Potassium-Exchanging ATPase