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Kaiser J, Gertzen CG, Bernauer T, Höfner G, Niessen KV, Seeger T, Paintner FF, Wanner KT, Worek F, Thiermann H, Gohlke H. A novel binding site in the nicotinic acetylcholine receptor for MB327 can explain its allosteric modulation relevant for organophosphorus-poisoning treatment. Toxicol Lett 2022; 373:160-171. [DOI: 10.1016/j.toxlet.2022.11.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/25/2022] [Indexed: 11/27/2022]
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John H, Dentzel M, Siegert M, Thiermann H. Nontargeted High-Resolution Mass Spectrometric Workflow for the Detection of Butyrylcholinesterase-Derived Adducts with Organophosphorus Toxicants and Structural Characterization of Their Phosphyl Moiety after In-Source Fragmentation. Anal Chem 2022; 94:2048-2055. [PMID: 35041786 DOI: 10.1021/acs.analchem.1c04116] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Organophosphorus (OP) nerve agents were used for chemical warfare, assassination, and attempted murder of individuals. Therefore, forensic methods are required to identify known and unknown incorporated OP poisons. Serum is tested for the presence of covalent reaction products (adducts) of the toxicant with, e.g., butyrylcholinesterase (BChE) typically by targeted analysis, thus only detecting known OP adducts. We herein present a nontargeted two-step mass spectrometry (MS)-based workflow taking advantage of a high-resolution (HR) Orbitrap mass spectrometer and its option for in-source collision-induced dissociation (IS-CID) highly valuable for the detection of unknown agents. BChE adducts are extracted by immunomagnetic separation and proteolyzed with pepsin yielding a phosphylated nonapeptide (NP) biomarker NP(OP). In step 1, the sample is separated by micro liquid chromatography (μLC) detecting the NP(OP) by nontargeted HR MS followed by data-dependent tandem-MS (ddMS2). Extracted ion chromatograms of diagnostic product ions at m/z 778.33661, 673.29402, and 602.25690 reveal the accurate mass of the NP(OP) precursor ion as well as the elemental composition of the adducted phosphyl moiety. Considering this information, a second μLC run is performed (step 2) for nonselective IS-CID of NP(OP) yielding the cleaved charged phosphyl moiety. This fragment ion is immediately subjected to targeted CID in parallel reaction monitoring (PRM). The accurate mass of its product ions allows the determination of their elemental composition and thus supports its structural elucidation. The described workflow was exemplarily applied to NP(OP) of three Tamelin esters and VX providing highly appropriate abilities for the detection of adducts even of unknown OP poisons like Novichok agents.
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Affiliation(s)
- Harald John
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstrasse 11, 80937 Munich, Germany
| | - Marina Dentzel
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstrasse 11, 80937 Munich, Germany
| | - Markus Siegert
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstrasse 11, 80937 Munich, Germany.,Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Berlin, Germany
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstrasse 11, 80937 Munich, Germany
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Thiermann H, Worek F. Oximes should be used routinely in organophosphate poisoning. Br J Clin Pharmacol 2022; 88:5064-5069. [PMID: 35023196 DOI: 10.1111/bcp.15215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 10/25/2021] [Accepted: 11/02/2021] [Indexed: 11/30/2022] Open
Abstract
In poisoning with organophosphorus compounds, patients can only profit from the regeneration of acetylcholinesterase, when the poison load has dropped below a toxic level. Every measure that allows an increase of synaptic AChE activity at the earliest is essential for timely termination of the cholinergic crisis. Only a drug induced reactivation allows to achieve fast restoration of the inhibited AChE. Obidoxime and pralidoxime have proved to be able to reactivate inhibited cholinesterase thereby saving life of poisoned animals. A plasma level of obidoxime or pralidoxime allowing reactivation in humans poisoned by OP can be adjusted. There is no doubt that obidoxime and pralidoxime are able to reactivate OP inhibited AChE activity in poisoned patients thereby increasing AChE activity and contributing substantially to terminate cholinergic crisis. Hence, a benefit may be expected when substantial reactivation is achieved. A test system allowing determination of red blood cell AChE activity, reactivatability, inhibitory equivalents and BChE activity is available for relatively low cost. If any reactivation is possible while inhibiting equivalents are present, oxime therapy should be maintained. In particular, when balancing the benefit risk assessment, obidoxime or palidoxime should be given as soon as possible and as long as a substantial reactivation may be expected.
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Affiliation(s)
- Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
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Saeidian H, Hosseini SE, Babri M. DFT calculations, microsynthesis and characterization of isopropyl methylphosphonoselenofluoridate [sarin-Se]. PHOSPHORUS SULFUR 2018. [DOI: 10.1080/10426507.2018.1487429] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Hamid Saeidian
- Department of Science, Payame Noor University (PNU), Tehran, P.O. Box: 19395-4697, Iran
| | | | - Mehran Babri
- Defense Chemical Research Lab (DCRL), Karaj, P.O. Box: 31585-1461, Iran
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Scheffel C, Niessen KV, Rappenglück S, Wanner KT, Thiermann H, Worek F, Seeger T. Electrophysiological investigation of the effect of structurally different bispyridinium non-oxime compounds on human α7-nicotinic acetylcholine receptor activity—An in vitro structure-activity analysis. Toxicol Lett 2018; 293:157-166. [DOI: 10.1016/j.toxlet.2017.11.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/11/2017] [Accepted: 11/22/2017] [Indexed: 02/01/2023]
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Niessen K, Seeger T, Rappenglück S, Wein T, Höfner G, Wanner K, Thiermann H, Worek F. In vitro pharmacological characterization of the bispyridinium non-oxime compound MB327 and its 2- and 3-regioisomers. Toxicol Lett 2018; 293:190-197. [DOI: 10.1016/j.toxlet.2017.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 09/29/2017] [Accepted: 10/08/2017] [Indexed: 11/27/2022]
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Moyer RA, McGarry KG, Babin MC, Platoff GE, Jett DA, Yeung DT. Kinetic analysis of oxime-assisted reactivation of human, Guinea pig, and rat acetylcholinesterase inhibited by the organophosphorus pesticide metabolite phorate oxon (PHO). Pestic Biochem Physiol 2018; 145:93-99. [PMID: 29482737 PMCID: PMC5830159 DOI: 10.1016/j.pestbp.2018.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 12/14/2017] [Accepted: 01/19/2018] [Indexed: 06/08/2023]
Abstract
UNLABELLED Phorate is a highly toxic agricultural pesticide currently in use throughout the world. Like many other organophosphorus (OP) pesticides, the primary mechanism of the acute toxicity of phorate is acetylcholinesterase (AChE) inhibition mediated by its bioactivated oxon metabolite. AChE reactivation is a critical aspect in the treatment of acute OP intoxication. Unfortunately, very little is currently known about the capacity of various oximes to rescue phorate oxon (PHO)-inhibited AChE. To help fill this knowledge gap, we evaluated the kinetics of inhibition, reactivation, and aging of PHO using recombinant AChE derived from three species (rat, guinea pig and human) commonly utilized to study the toxicity of OP compounds and five oximes that are currently fielded (or have been deemed extremely promising) as anti-OP therapies by various nations around the globe: 2-PAM Cl, HI-6 DMS, obidoxime Cl2, MMB4-DMS, and HLö7 DMS. The inhibition rate constants (ki) for PHO were calculated for AChE derived from each species and found to be low (i.e., 4.8×103 to 1.4×104M-1min-1) compared to many other OPs. Obidoxime Cl2 was the most effective reactivator tested. The aging rate of PHO-inhibited AChE was very slow (limited aging was observed out to 48h) for all three species. CONCLUSIONS (1) Obidoxime Cl2 was the most effective reactivator tested. (2) 2-PAM Cl, showed limited effectiveness in reactivating PHO-inhibited AChE, suggesting that it may have limited usefulness in the clinical management of acute PHO intoxication. (3) The therapeutic window for oxime administration following exposure to phorate (or PHO) is not limited by aging.
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Affiliation(s)
| | | | | | - Gennady E Platoff
- National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, MD, United States
| | - David A Jett
- National Institutes of Health/National Institute of Neurological Disorders and Stroke, Rockville, MD, United States
| | - David T Yeung
- National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, MD, United States
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Greget R, Dadak S, Barbier L, Lauga F, Linossier-Pierre S, Pernot F, Legendre A, Ambert N, Bouteiller JM, Dorandeu F, Bischoff S, Baudry M, Fagni L, Moussaoui S. Modeling and simulation of organophosphate-induced neurotoxicity: Prediction and validation by experimental studies. Neurotoxicology 2016; 54:140-152. [PMID: 27108687 DOI: 10.1016/j.neuro.2016.04.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/07/2016] [Accepted: 04/19/2016] [Indexed: 02/07/2023]
Abstract
Exposure to organophosphorus (OP) compounds, either pesticides or chemical warfare agents, represents a major health problem. As potent irreversible inhibitors of cholinesterase, OP may induce seizures, as in status epilepticus, and occasionally brain lesions. Although these compounds are extremely toxic agents, the search for novel antidotes remains extremely limited. In silico modeling constitutes a useful tool to identify pharmacological targets and to develop efficient therapeutic strategies. In the present work, we developed a new in silico simulator in order to predict the neurotoxicity of irreversible inhibitors of acetyl- and/or butyrylcholinesterase (ChE) as well as the potential neuroprotection provided by antagonists of cholinergic muscarinic and glutamate N-methyl-d-aspartate (NMDA) receptors. The simulator reproduced firing of CA1 hippocampal neurons triggered by exposure to paraoxon (POX), as found in patch-clamp recordings in in vitro mouse hippocampal slices. In the case of POX intoxication, it predicted a preventing action of the muscarinic receptor antagonist atropine sulfate, as well as a synergistic action with the non-competitive NMDA receptor antagonist memantine. These in silico predictions relative to beneficial effects of atropine sulfate combined with memantine were recapitulated experimentally in an in vivo model of POX in adult male Swiss mice using electroencephalic (EEG) recordings. Thus, our simulator is a new powerful tool to identify protective therapeutic strategies against OP central effects, by screening various combinations of muscarinic and NMDA receptor antagonists.
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Affiliation(s)
| | - Selma Dadak
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, INSERM, U1191, Université de Montpellier, Montpellier F-34094, France
| | - Laure Barbier
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France
| | - Fabien Lauga
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France
| | - Sandra Linossier-Pierre
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France
| | | | | | | | | | - Frédéric Dorandeu
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France; Ecole du Val-de-Grâce, Paris, France
| | | | | | - Laurent Fagni
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, INSERM, U1191, Université de Montpellier, Montpellier F-34094, France
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El-Moghazy AY, Soliman EA, Ibrahim HZ, Noguer T, Marty JL, Istamboulie G. Ultra-sensitive biosensor based on genetically engineered acetylcholinesterase immobilized in poly (vinyl alcohol)/Fe-Ni alloy nanocomposite for phosmet detection in olive oil. Food Chem 2016; 203:73-78. [PMID: 26948591 DOI: 10.1016/j.foodchem.2016.02.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 01/13/2016] [Accepted: 02/01/2016] [Indexed: 10/22/2022]
Abstract
An ultra-sensitive screen-printed biosensor was successfully developed for phosmet detection in olive oil, based on a genetically-engineered acetylcholinesterase (AChE) immobilized in a azide-unit water-pendant polyvinyl alcohol (PVA-AWP)/Fe-Ni alloy nanocomposite. Fe-Ni not only allowed amplifying the response current but also lowering the applied potential from 80 mV to 30 mV vs Ag/AgCl. The biosensor showed a very good analytical performance for phosmet detection, with a detection limit of 0.1 nM. This detection limit is lower than the allowable concentrations set by international regulations. In addition to the good reproducibility, operational and storage stability, the developed biosensor was successfully used for the determination of phosmet in olive oil samples without any laborious pre-treatment. The phosmet recovery rate was about 96% after a simple liquid-liquid extraction.
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Affiliation(s)
- A Y El-Moghazy
- BAE: Biocapteurs-Analyss-Environnement, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan Cedex 66860, France; Polymeric Materials Department, Advanced Technology and New Materials Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Alexandria, P.O. Box: 21934, Egypt
| | - E A Soliman
- Polymeric Materials Department, Advanced Technology and New Materials Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Alexandria, P.O. Box: 21934, Egypt
| | - H Z Ibrahim
- Department of Environmental Studies, Institute of Graduate Studies and Research, Alexandria University, P.O. Box 832, Alexandria, Egypt
| | - T Noguer
- BAE: Biocapteurs-Analyss-Environnement, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan Cedex 66860, France
| | - J-L Marty
- BAE: Biocapteurs-Analyss-Environnement, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan Cedex 66860, France
| | - G Istamboulie
- BAE: Biocapteurs-Analyss-Environnement, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan Cedex 66860, France
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da Cunha Xavier Soares SF, Vieira AA, Delfino RT, Figueroa-Villar JD. NMR determination of Electrophorus electricus acetylcholinesterase inhibition and reactivation by neutral oximes. Bioorg Med Chem 2013; 21:5923-30. [DOI: 10.1016/j.bmc.2013.05.063] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 05/21/2013] [Accepted: 05/29/2013] [Indexed: 12/20/2022]
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Abney CW, Knaack JLS, Ali AAI, Johnson RC. Novel Dual-Mode Immunomagnetic Method for Studying Reactivation of Nerve Agent-Inhibited Butyrylcholinesterase. Chem Res Toxicol 2013; 26:775-82. [DOI: 10.1021/tx4000717] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Carter W. Abney
- Oak Ridge Institute for Science
and Education Fellow at the Centers for Disease Control and Prevention, 4770 Buford Highway, MS F44, Chamblee,
Georgia 30341, United States
| | - Jennifer L. S. Knaack
- Division of Laboratory Sciences,
National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
| | - Ahmed A. I. Ali
- Oak Ridge Institute for Science
and Education Fellow at the Centers for Disease Control and Prevention, 4770 Buford Highway, MS F44, Chamblee,
Georgia 30341, United States
| | - Rudolph C. Johnson
- Division of Laboratory Sciences,
National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
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Lugokenski TH, Gubert P, Bueno DC, Nogara PA, de Aquino Saraiva R, Barcelos RP, Carratu VS, Bresolin L, de Vargas Barbosa NB, Pereira ME, da Rocha JBT, Soares FAA. Effect of different oximes on rat and human cholinesterases inhibited by methamidophos: a comparative in vitro and in silico study. Basic Clin Pharmacol Toxicol 2012; 111:362-70. [PMID: 22703537 DOI: 10.1111/j.1742-7843.2012.00912.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2011] [Accepted: 05/25/2012] [Indexed: 11/29/2022]
Abstract
Methamidophos is one of the most toxic organophosphorus (OP) compounds. It acts via phosphorylation of a serine residue in the active site of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), leading to enzyme inactivation. Different oximes have been developed to reverse this inhibition. Thus, our work aimed to test the protective or reactivation capability of pralidoxime and obidoxime, as well as two new oximes synthesised in our laboratory, on human and rat cholinesterases inhibited by methamidophos. In addition, we performed molecular docking studies in non-aged methamidophos-inhibited AChE to understand the mechanisms involved. Our results suggested that pralidoxime protected and reactivated methamidophos-inhibited rat brain AChE. Regarding human erythrocyte AChE, all oximes tested protected and reactivated the enzyme, with the best reactivation index observed at the concentration of 50 μM. Concerning BChE, butane-2,3-dionethiosemicarbazone oxime (oxime 1) was able to protect and reactivate the methamidophos-inhibited BChE by 45% at 50 μM, whereas 2(3-(phenylhydrazono)butan-2-one oxime (oxime 2) reactivated 28% of BChE activity at 100 μM. The two classical oximes failed to reactivate BChE. The molecular docking study demonstrated that pralidoxime appears to be better positioned in the active site to attack the O-P moiety of the inhibited enzyme, being near the oxyanion hole, whereas our new oximes were stably positioned in the active site in a manner similar to that of obidoxime. In conclusion, our work demonstrated that the newly synthesised oximes were able to reactivate not only human erythrocyte AChE but also human plasma BChE, which could represent an advantage in the treatment of OP compounds poisoning.
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Seeger T, Niessen K, Langer P, Gerhardus J, Worek F, Friess H, Bumm R, Mihaljevic A, Thiermann H. Restoration of nerve agent inhibited muscle force production in human intercostal muscle strips with HI 6. Toxicol Lett 2011; 206:72-6. [DOI: 10.1016/j.toxlet.2011.07.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 06/21/2011] [Accepted: 07/15/2011] [Indexed: 01/17/2023]
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Niessen K, Tattersall J, Timperley C, Bird M, Green C, Seeger T, Thiermann H, Worek F. Interaction of bispyridinium compounds with the orthosteric binding site of human α7 and Torpedo californica nicotinic acetylcholine receptors (nAChRs). Toxicol Lett 2011; 206:100-4. [DOI: 10.1016/j.toxlet.2011.06.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 06/06/2011] [Accepted: 06/08/2011] [Indexed: 11/28/2022]
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Maselli RA, Henderson JD, Ng J, Follette D, Graves G, Wilson BW. Protection of human muscle acetylcholinesterase from soman by pyridostigmine bromide. Muscle Nerve 2011; 43:591-5. [PMID: 21404290 DOI: 10.1002/mus.21922] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
INTRODUCTION Pretreatment with pyridostigmine bromide (PB) of human intercostal muscle fibers exposed to the irreversible acetylcholinesterase (AChE) inhibitor soman was investigated. METHODS Muscles were pretreated with 3 × 10(-6) M PB or saline for 20 minutes, then exposed to 10(-7) M soman for 10 minutes. RESULTS AChE of muscles treated with soman alone was inhibited >95%. In contrast, PB pretreatment of soman-exposed bundles protected 20% of AChE activity. AChE of bundles exposed to PB alone recovered after 4 hours, but bundles exposed to both PB and soman did not. Soman-induced reduction of resting membrane potentials and increment of amplitudes and decay times of miniature endplate potentials (MEPPs) were partially corrected by PB pretreatment. CONCLUSIONS In vitro pretreatment of human muscles with PB protected up to 20% of muscle AChE and ameliorated some deleterious effects on endplate physiology induced by soman.
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Affiliation(s)
- Ricardo A Maselli
- Department of Neurology, University of California Davis, Davis, California, USA
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Thiermann H, Seeger T, Gonder S, Herkert N, Antkowiak B, Zilker T, Eyer F, Worek F. Assessment of neuromuscular dysfunction during poisoning by organophosphorus compounds. Chem Biol Interact 2010; 187:265-9. [DOI: 10.1016/j.cbi.2009.12.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 12/17/2009] [Accepted: 12/21/2009] [Indexed: 10/20/2022]
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Worek F, Aurbek N, Wille T, Eyer P, Thiermann H. Kinetic prerequisites of oximes as effective reactivators of organophosphate-inhibited acetylcholinesterase: a theoretical approach. J Enzyme Inhib Med Chem 2010; 26:303-8. [DOI: 10.3109/14756366.2010.504673] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Nadine Aurbek
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Timo Wille
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Peter Eyer
- Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
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Musilek K, Dolezal M, Gunn-Moore F, Kuca K. Design, evaluation and structure-activity relationship studies of the AChE reactivators against organophosphorus pesticides. Med Res Rev 2009; 31:548-75. [PMID: 20027669 DOI: 10.1002/med.20192] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Organophosphate pesticides (OPPs; e.g. chlorpyrifos, diazinon, paraoxon) are a wide and heterogeneous group of organophosphorus compounds. Their biological activity of inhibiting acetylcholinesterase (AChE) or butyrylcholinesterase (BChE) ranks them as life endangering agents. The necessary treatment after OPP exposure involves the use of parasympatolytics (e.g. atropine), oxime reactivators (e.g. obidoxime), and anticonvulsive drugs (e.g. diazepam). Therefore, the reactivators of AChE are essential compounds in the treatment of OPP intoxications. Commercial AChE reactivators (e.g. pralidoxime, HI-6, obidoxime, trimedoxime, methoxime) were originally developed for other members of the organophosphate family, such as nerve agents (e.g. sarin, soman, tabun, VX). Pralidoxime, HI-6, and methoxime were found to be weak reactivators of OPP-inhibited AChE. Obidoxime and trimedoxime showed satisfactory reactivation against various OPPs with minor toxicity issues. During the last two decades, the treatment of OPP exposure has become more widely discussed because of growing agricultural production, industrialization, and harmful social issues (e.g. suicides). In this review is the summarized design, evaluation, and structure-activity relationship studies of recently produced AChE reactivators. Since pralidoxime, over 300 oximes have been produced or tested against OPP poisoning, and several novel compounds show very promising abilities as comparable (or higher) to commercial oximes. Some of these are highlighted for their further testing of OPP exposure and, additionally, the main structure-activity relationship of AChE reactivators against OPP is discussed.
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Affiliation(s)
- Kamil Musilek
- Department of Toxicology, Trebesska, Hradec Kralove, Czech Republic.
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Raszewski G, Filip R. Correlation of Therapeutic Effect of Obidoxime and Dosing Time in the Acute Intoxication by Chlorfenvinphos in Rats. Basic Clin Pharmacol Toxicol 2009; 105:37-45. [DOI: 10.1111/j.1742-7843.2009.00398.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Tiwari S, Kolay S, Ghosh KK, Kuca K, Marek J. Kinetic study of the reactions ofp-nitrophenyl acetate andp-nitrophenyl benzoate with oximate nucleophiles. INT J CHEM KINET 2009. [DOI: 10.1002/kin.20363] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Worek F, Eyer P, Aurbek N, Szinicz L, Thiermann H. Recent advances in evaluation of oxime efficacy in nerve agent poisoning by in vitro analysis. Toxicol Appl Pharmacol 2007; 219:226-34. [DOI: 10.1016/j.taap.2006.10.001] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2006] [Revised: 09/30/2006] [Accepted: 10/02/2006] [Indexed: 10/24/2022]
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Taylor P, Kovarik Z, Reiner E, Radić Z. Acetylcholinesterase: converting a vulnerable target to a template for antidotes and detection of inhibitor exposure. Toxicology 2006; 233:70-8. [PMID: 17196318 PMCID: PMC3279330 DOI: 10.1016/j.tox.2006.11.061] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2006] [Revised: 10/23/2006] [Accepted: 11/13/2006] [Indexed: 10/23/2022]
Abstract
Applications of recombinant DNA technology, chemical synthesis on biological templates and fluorescence detection of organophosphorylation provide unexplored avenues for development of antidotes and approaches for remote detection of organophosphate nerve agents and pesticides. We discuss here how acetylcholinesterase (AChE), through appropriate mutations, becomes more susceptible to oxime reactivation. Since the reaction between organophosphate and the mutated enzyme remains rapid, regeneration of active enzyme by oxime becomes the rate-limiting step in the process to complete a catalytic cycle for generation of active enzyme. Accordingly, "Oxime-assisted Catalysis" by AChE provides a potential means for catalyzing the hydrolysis of organophosphates in plasma prior to their reaching the cellular target site. In turn, AChE, when conjugated with organophosphate, is employed as a template for 'click-chemistry, freeze-frame' synthesis of new nucleophilic reactivating agents that could potentially prove useful in AChE reactivation at the target site as well as in catalytic scavenging of organophosphates in plasma. Finally, substituted AChE molecules can be conjugated to fluorophores giving rise to shifts in emission spectra for detection of dispersed organophosphates. Since external reagents do not have to be added to detect the fluorescence change, the modified enzyme would serve as a remote sensor.
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Affiliation(s)
- Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093-0650, USA.
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Thiermann H, Szinicz L, Eyer P, Felgenhauer N, Zilker T, Worek F. Lessons to be learnt from organophosphorus pesticide poisoning for the treatment of nerve agent poisoning. Toxicology 2006; 233:145-54. [PMID: 17161895 DOI: 10.1016/j.tox.2006.11.056] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Revised: 10/17/2006] [Accepted: 11/13/2006] [Indexed: 10/23/2022]
Abstract
The increasing threat of nerve agent use for terrorist purposes against civilian and military population calls for effective therapeutic preparedness. At present, administration of atropine and an oxime are recommended, although effectiveness of this treatment is not proved in clinical trials. Here, monitoring of intoxications with organophosphorus (OP) pesticides may be of help, as their actions are closely related to those of nerve agents and intoxication and therapy follow the same principles. To this end, the clinical course of poisoning and the effectiveness of antidotal therapy were investigated in patients requiring artificial ventilation being treated with atropine and obidoxime. However, poisoning with OP pesticides shows extremely heterogeneous pictures of cholinergic crisis frequently associated with clinical complications. To achieve valuable information for the therapy of nerve agent poisoning, cases resembling situations in nerve agent poisoning had to be extracted: (a) intoxication with OPs forming reactivatable OP-AChE-complexes with short persistence of the OP in the body resembling inhalational sarin intoxication; (b) intoxication with OPs resulting rapidly in an aged OP-AChE-complex resembling inhalational soman intoxication; (c) intoxications with OPs forming a reactivatable AChE-OP complex with prolonged persistence of the OP in the body resembling percutaneous VX intoxication. From these cases it was concluded that sufficient reactivation of nerve agent inhibited non-aged AChE should be possible, if the poison load was not too high and the effective oximes were administered early and with an appropriate duration. When RBC-AChE activity was higher than some 30%, neuromuscular transmission was relatively normal. Relatively low atropine doses (several milligrams) should be sufficient to cope with muscarinic symptoms during oxime therapy.
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Affiliation(s)
- H Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937 Munich, Germany.
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Stefanovic D, Antonijevic B, Bokonjic D, Stojiljkovic MP, Milovanovic ZA, Nedeljkovic M. Effect of Sodium Bicarbonate in Rats Acutely Poisoned with Dichlorvos. Basic Clin Pharmacol Toxicol 2006; 98:173-80. [PMID: 16445591 DOI: 10.1111/j.1742-7843.2006.pto_68.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The development of effective antidotes against organophosphates such as dichlorvos has been a persistent challenge over the past decades. Therapy of organophosphate poisoning is based on the administration of atropine and oxime as standard antidotes. The present study was undertaken to evaluate the ability of sodium bicarbonate to improve protective effects of standard antidotes in rats poisoned with dichlorvos. The aim of this experiment was to establish the correlation between protective effects and biochemical parameters relevant for acid-base status. In order to examine the protective effect of both standard antidotes and their combinations, groups of experimental animals were poisoned subcutaneously with increasing doses of dichlorvos. Immediately thereafter, rats were treated with atropine 10 mg/kg intramuscularly, oximes 10 mg/kg intramuscularly and sodium bicarbonate 3 mmol/kg intraperitoneally. These antidotes were administered either as single doses or in combinations. In the biochemical part of the experiments, rats were poisoned with dichlorvos 1.3 LD(50) (10.64 mg/kg) subcutaneously and immediately thereafter treated with atropine 10 mg/kg intramuscularly, oximes (trimedoxime or obidoxime) 10 mg/kg intramuscularly and sodium bicarbonate 3 mmol/kg intraperitoneally either as single doses or in combinations. Parameters relevant for acid-base status were measured 10 minutes after the administration of antidotes. The results of our study indicate that addition of sodium bicarbonate to standard antidotes significantly improves protective effects of atropine, obidoxime and trimedoxime. Correlation between protection and biochemical outcome is clearly evident when sodium bicarbonate is being added to atropine.
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Affiliation(s)
- Danka Stefanovic
- Institute of Toxicological Chemistry, School of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11 221 Belgrade, Serbia and Montenegro.
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Antonijević B, Bokonjić D, Stojiljković MP, Kilibarda V, Milovanović ZA, Nedeljković M, Maksimović M. Efficacy of Trimedoxime in Mice Poisoned with Dichlorvos, Heptenophos or Monocrotophos. Basic Clin Pharmacol Toxicol 2005; 96:111-7. [PMID: 15679473 DOI: 10.1111/j.1742-7843.2005.pto960204.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim of the study was to examine antidotal potency of trimedoxime in mice poisoned with three direct dimethoxy-substituted organophosphorus inhibitors. In order to assess the protective efficacy of trimedoxime against dichlorvos, heptenophos or monocrotophos, median effective doses and efficacy half-times were calculated. Trimedoxime (24 mg/kg intravenously) was injected 5 min. before 1.3 LD50 intravenously of poisons. Activities of brain, diaphragmal and erythrocyte acetylcholinesterase, as well as of plasma carboxylesterases were determined at different time intervals (10, 40 and 60 min.) after administration of the antidotes. Protective effect of trimedoxime decreased according to the following order: monocrotophos > heptenophos > dichlorvos. Administration of the oxime produced a significant reactivation of central and peripheral acetylcholinesterase inhibited with dichlorvos and heptenophos, with the exception of erythrocyte acetylcholinesterase inhibited by heptenophos. Surprisingly, trimedoxime did not induce reactivation of monocrotophos-inhibited acetylcholinesterase in any of the tissues tested. These organophosphorus compounds produced a significant inhibition of plasma carboxylesterase activity, while administration of trimedoxime led to regeneration of the enzyme activity. The same dose of trimedoxime assured survival of experimental animals poisoned by all three organophosphorus compounds, although the biochemical findings were quite different.
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Affiliation(s)
- Biljana Antonijević
- Institute of Toxicological Chemistry, School of Pharmacy, University of Belgrade, Vojvode Stepe 450, Serbia and Montenegro.
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