We have in vitro tested the ability of common, commercially available, cholinesterase reactivators (pralidoxime, obidoxime, methoxime, trimedoxime and HI-6) to reactivate human acetylcholinesterase (AChE), inhibited by five structurally different organophosphate pesticides and inhibitors (paraoxon, dichlorvos, DFP, leptophos-oxon and methamidophos). We also tested reactivation of human butyrylcholinesterase (BChE) with the aim of finding a potent oxime, suitable to serve as a "pseudocatalytic" bioscavenger in combination with this enzyme. Such a combination could allow an increase of prophylactic and therapeutic efficacy of the administered enzyme. According to our results, the best broad-spectrum AChE reactivators were trimedoxime and obidoxime in the case of paraoxon, leptophos-oxon, and methamidophos-inhibited AChE. Methamidophos and leptophos-oxon were quite easily reactivatable by all tested reactivators. In the case of methamidophos-inhibited AChE, the lower oxime concentration (10(-5) M) had higher reactivation ability than the 10(-4) M concentration. Therefore, we evaluated the reactivation ability of obidoxime in a concentration range of 10(-3)-10(-7) M. The reactivation of methamidophos-inhibited AChE with different obidoxime concentrations resulted in a bell shaped curve with maximum reactivation at 10(-5) M. In the case of BChE, no reactivator exceeded 15% reactivation ability and therefore none of the oximes can be recommended as a candidate for "pseudocatalytic" bioscavengers with BChE.

Center of Advanced Studies Faculty of Military Health Sciences University of Defence Trebesska 1575 Hradec Kralove 500 01 Czech Republic

Zobrazit více v PubMed

Costa LG. Current issues in organophosphate toxicology. Clin. Chim. Acta. 2006;366:1–13. PubMed

Maxwell DM, Brecht KM, Koplovitz I, Sweeney RE. Acetylcholinesterase inhibition: Does it explain the toxicity of organophosphorus compounds? Arch. Toxicol. 2006;80:756–760. PubMed

Worek F, Koller M, Thiermann H, Szinicz L. Diagnostic aspects of organophosphate poisoning. Toxicology. 2005;214:182–189. PubMed

Elhanany E, Ordentlich A, Dgany O, Kaplan D, Segall Y, Barak R, Velan B, Shafferman A. Resolving pathways of interaction of covalent inhibitors with the active site of acetylcholinesterases: MALDI-TOF/MS analysis of various nerve agent phosphyl adducts. Chem. Res. Toxicol. 2001;14:912–918. PubMed

Barak D, Ordentlich A, Kaplan D, Barak R, Mizrahi D, Kronman C, Segall Y, Velan B, Shafferman A. Evidence for P-N bond scission in phosphoroamidate nerve agent adducts of human acetylcholinesterase. Biochemistry. 2000;39:1156–1161. PubMed

Millard CB, Kryger G, Ordentlich A, Greenblatt HM, Harel M, Raves ML, Segall Y, Barak D, Shafferman A, Silman I, Sussman JL. Crystal structures of aged phosphonylated acetylcholinesterase: Nerve agent reaction products at the atomic level. Biochemistry. 1999;38:7032–7039. PubMed

Eyer P. The role of oximes in the management of organophosphorus pesticide poisoning. Toxicol. Rev. 2003;22:165–190. PubMed

Worek F, Backer M, Thiermann H, Szinicz L, Mast U, Klimmek R, Eyer P. Reappraisal of indications and limitations of oxime therapy in organophosphate poisoning. Hum. Exp. Toxicol. 1997;16:466–472. PubMed

Thompson DF, Thompson GD, Greenwood RB, Trammel HL. Therapeutic dosing of pralidoxime chloride. Drug Intell. Clin. Pharm. 1987;21:590–593. PubMed

Eddleston M, Singh S, Buckley N. Acute organophosphorus poisoning. Clin Evid. June. 2003:1542–1553. PubMed

Bajgar J, Fusek J, Kuca K, Bartosova L, Jun D. Treatment of organophosphate intoxication using cholinesterase reactivators: Facts and fiction. Mini. Rev. Med. Chem. 2007;7:461–466. PubMed

Saxena A, Sun W, Luo C, Myers TM, Koplovitz I, Lenz DE, Doctor BP. Bioscavenger for protection from toxicity of organophosphorus compounds. J. Mol. Neurosci. 2006;30:145–148. PubMed

Maxwell DM, Brecht KM, Doctor BP, Wolfe AD. Comparison of antidote protection against soman by pyridostigmine, HI-6 and acetylcholinesterase. J. Pharmacol. Exp. Ther. 1993;264:1085–1089. PubMed

Kolarich D, Weber A, Pabst M, Stadlmann J, Teschner W, Ehrlich H, Schwarz HP, Altmann F. Glycoproteomic characterization of butyrylcholinesterase from human plasma. Proteomics. 2008;8:254–263. PubMed

Lenz DE, Yeung D, Smith JR, Sweeney RE, Lumley LA, Cerasoli DM. Stoichiometric and catalytic scavengers as protection against nerve agent toxicity: A mini review. Toxicology. 2007;233:31–39. PubMed

Jun D, Musilova L, Link M, Loiodice M, Nachon F, Rochu D, Renault F, Masson P. Preparation and characterization of methoxy polyethylene glycol-conjugated phosphotriesterase as a potential catalytic bioscavenger against organophosphate poisoning. Chem. Biol.Inter. 2010;187:380–383. PubMed

Jun D, Musilova L, Kuca K, Kassa J, Bajgar J. Potency of several oximes to reactivate human acetylcholinesterase and butyrylcholinesterase inhibited by paraoxon in vitro. Chem. Biol. Inter. 2008;175:421–424. PubMed

Bajgar EJ. Central and Peripheral Nervous System: Effects of Highly Toxic Organophosphates and Their Antidotes. Research Signpost; Kerala, India: 2009.

Jun D, Musilova L, Pohanka M, Jung YS, Bostik P, Kuca K. Reactivation of human acetylcholinesterase and butyrylcholinesterase inhibited by leptophos-oxon with different oxime reactivators in vitro. Int. J.Mol. Sci. 2010;11:2856–2863. PubMed PMC

Bajgar J. Organophosphates/nerve agent poisoning: Mechanism of action, diagnosis, prophylaxis, and treatment. Adv. Clin. Chem. 2004;38:151–216. PubMed

Lorke DE, Nurulain SM, Hasan MY, Kuca K, Musilek K, Petroianu GA. Eight new bispyridinium oximes in comparison with the conventional oximes pralidoxime and obidoxime: In vivo efficacy to protect from diisopropylfluorophosphate toxicity. J. Appl. Toxicol. 2008;28:920–928. PubMed

Musilek K, Kuca K, Jun D, Dohnal V, Dolezal M. Synthesis of a novel series of bispyridinium compounds bearing a xylene linker and evaluation of their reactivation activity against chlorpyrifos-inhibited acetylcholinesterase. J. Enzyme Inhib. Med. Chem. 2005;20:409–415. PubMed

Kuca K, Cabal J, Jun D, Hrabinova M. In vitro evaluation of acetylcholinesterase reactivators as potential antidotes against tabun nerve agent poisonings. Drug Chem. Toxicol. 2006;29:443–449. PubMed

Kuca K, Kassa J. A comparison of the ability of a new bispyridinium oxime-1-(4-hydroxyiminomethylpyridinium)-4-(4-carbamoylpyridinium)butane dibromide and currently used oximes to reactivate nerve agent-inhibited rat brain acetylcholinesterase by in vitro methods. J. Enzyme Inhib. Med. Chem. 2003;18:529–535. PubMed

Kuca K, Musilova L, Palecek J, Cirkva V, Paar M, Musilek K, Hrabinova M, Pohanka M, Karasova JZ, Jun D. Novel bisquaternary oximes—Reactivation of acetylcholinesterase and butyrylcholinesterase inhibited by paraoxon. Molecules. 2009;14:4915–4921. PubMed PMC

Stenzel J, Worek F, Eyer P. Preparation and characterization of dialkylphosphoryl-obidoxime conjugates, potent anticholinesterase derivatives that are quickly hydrolyzed by human paraoxonase (PON1192Q) Biochem. Pharmacol. 2007;74:1390–1400. PubMed

Worek F, Diepold C, Eyer P. Dimethylphosphoryl-inhibited human cholinesterases: Inhibition, reactivation, and aging kinetics. Arch. Toxicol. 1999;73:7–14. PubMed

Kiderlen D, Worek F, Klimmek R, Eyer P. The phosphoryl oxime-destroying activity of human plasma. Arch. Toxicol. 2000;74:27–32. PubMed

Aurbek N, Thiermann H, Eyer F, Eyer P, Worek F. Suitability of human butyrylcholinesterase as therapeutic marker and pseudo catalytic scavenger in organophosphate poisoning: A kinetic analysis. Toxicology. 2009;259:133–139. PubMed

Ellman GL, Courtney KD, Andres V, Jr, Feather-Stone RM. A new and rapid colorimetric determination of acetylcholinesterase activity. Biochem. Pharmacol. 1961;7:88–95. PubMed

Musilova L, Jun D, Palecek J, Cirkva V, Musilek K, Paar M, Hrabinova M, Pohanka M, Kuca K. Novel nucleophilic compounds with oxime group as reactivators of paraoxon-inhibited cholinesterases. Lett. Drug Design Disc. 2010;7:260–264.

Musilova L, Kuca K, Jung YS, Jun D. In vitro oxime-assisted reactivation of paraoxon-inhibited human acetylcholinesterase and butyrylcholinesterase. Clin. Toxicol. (Phila) 2009;47:545–550. PubMed

Trends in the Recent Patent Literature on Cholinesterase Reactivators (2016-2019)

Molecular Modeling and In Vitro Studies of a Neutral Oxime as a Potential Reactivator for Acetylcholinesterase Inhibited by Paraoxon

The benefit of combinations of oximes for the ability of antidotal treatment to counteract sarin-induced brain damage in rats

Synthesis, Biological Evaluation, and Docking Studies of Novel Bisquaternary Aldoxime Reactivators on Acetylcholinesterase and Butyrylcholinesterase Inhibited by Paraoxon