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Prchalova E, Andrys R, Pejchal J, Kohoutova Z, Knittelova K, Hofmanova T, Skarka A, Dlabkova A, Psotka M, Prchal L, Musilek K, Karasova JZ, Malinak D. Brominated oxime nucleophiles are efficiently reactivating cholinesterases inhibited by nerve agents. Arch Toxicol 2024; 98:2937-2952. [PMID: 38789714 DOI: 10.1007/s00204-024-03791-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024]
Abstract
Six novel brominated bis-pyridinium oximes were designed and synthesized to increase their nucleophilicity and reactivation ability of phosphorylated acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Their pKa was valuably found lower to parent non-halogenated oximes. Stability tests showed that novel brominated oximes were stable in water, but the stability of di-brominated oximes was decreased in buffer solution and their degradation products were prepared and characterized. The reactivation screening of brominated oximes was tested on AChE and BChE inhibited by organophosphorus surrogates. Two mono-brominated oximes reactivated AChE comparably to non-halogenated analogues, which was further confirmed by reactivation kinetics. The acute toxicity of two selected brominated oximes was similar to commercially available oxime reactivators and the most promising brominated oxime was tested in vivo on sarin- and VX-poisoned rats. This brominated oxime showed interesting CNS distribution and significant reactivation effectiveness in blood. The same oxime resulted with the best protective index for VX-poisoned rats.
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Affiliation(s)
- Eliska Prchalova
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
| | - Rudolf Andrys
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
| | - Jaroslav Pejchal
- University of Defence, Military Faculty of Medicine, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Zuzana Kohoutova
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
| | - Karolina Knittelova
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
| | - Tereza Hofmanova
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
| | - Adam Skarka
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
| | - Alzbeta Dlabkova
- University of Defence, Military Faculty of Medicine, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Miroslav Psotka
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
- University Hospital in Hradec Kralove, Biomedical Research Center, Sokolska 581, 500 05, Hradec Kralove, Czech Republic
| | - Lukas Prchal
- University Hospital in Hradec Kralove, Biomedical Research Center, Sokolska 581, 500 05, Hradec Kralove, Czech Republic
| | - Kamil Musilek
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
- University Hospital in Hradec Kralove, Biomedical Research Center, Sokolska 581, 500 05, Hradec Kralove, Czech Republic
| | - Jana Zdarova Karasova
- University of Defence, Military Faculty of Medicine, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic.
- University Hospital in Hradec Kralove, Biomedical Research Center, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.
| | - David Malinak
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic.
- University Hospital in Hradec Kralove, Biomedical Research Center, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.
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2
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Kohoutova Z, Prchalova E, Knittelova K, Musilek K, Malinak D. Reactivators of butyrylcholinesterase inhibited by organophosphorus compounds. Bioorg Chem 2024; 150:107526. [PMID: 38878749 DOI: 10.1016/j.bioorg.2024.107526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 05/16/2024] [Accepted: 06/02/2024] [Indexed: 07/21/2024]
Abstract
In this review, the current progress in the research and development of butyrylcholinesterase (BChE) reactivators is summarised and the advantages or disadvantages of these reactivators are critically discussed. Organophosphorus compounds such as nerve agents (sarin, tabun, VX) or pesticides (chlorpyrifos, diazinon) cause irreversible inhibition of acetylcholinesterase (AChE) and BChE in the human body. While AChE inhibition can be life threatening due to cholinergic overstimulation and crisis, selective BChE inhibition has presumably no adverse effects. Because BChE is mostly found in plasma, its activity is important for the scavenging of organophosphates before they can reach AChE in the central nervous system. Therefore, this enzyme in combination with its reactivator can be used as a pseudo-catalytic scavenger of organophosphates. Three structural types of BChE reactivators were found, i.e. bisquaternary salts, monoquaternary salts and uncharged compounds. Although the reviewed reactivators have certain limitations, the promising candidates for BChE reactivation were found in each structural group.
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Affiliation(s)
- Zuzana Kohoutova
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
| | - Eliska Prchalova
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
| | - Karolina Knittelova
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
| | - Kamil Musilek
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic; University Hospital in Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - David Malinak
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic; University Hospital in Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
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3
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Andrys R, Monnier C, Antonijević Miljaković E, Mickova V, Musilek K, Zemanova L. Towards cost-effective drug discovery: Reusable immobilized enzymes for neurological disease research. Talanta 2024; 276:126263. [PMID: 38788378 DOI: 10.1016/j.talanta.2024.126263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 05/08/2024] [Accepted: 05/14/2024] [Indexed: 05/26/2024]
Abstract
Enzyme handling and utilization bears many challenges such as their limited stability, intolerance of organic solvents, high cost, or inability to reuse. Most of these limitations can be overcome by enzyme immobilization on the surface of solid support. In this work, the recombinant form of human cholinesterases and monoamine oxidases as important drug targets for neurological diseases were immobilized on the surface of magnetic non-porous microparticles by a non-covalent bond utilizing the interaction between a His-tag terminus on the recombinant enzymes and cobalt (Co2+) ions immobilized on the magnetic microparticles. This type of binding led to targeted enzyme orientation, which completely preserved the catalytic activity and allowed high reproducibility of immobilization. In comparison with free enzymes, the immobilized enzymes showed exceptional stability in time and the possibility of repeated use. Relevant Km, Vmax, and IC50 values using known inhibitors were obtained using particular immobilized enzymes. Such immobilized enzymes on magnetic particles could serve as an excellent tool for a sustainable approach in the early stage of drug discovery.
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Affiliation(s)
- Rudolf Andrys
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic.
| | - Charline Monnier
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic.
| | - Evica Antonijević Miljaković
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic; Department of Toxicology "Akademik Danilo Soldatovic", University of Belgrade, Faculty of Pharmacy, Vojvode Stepe 450, 11 000, Belgrade, Serbia.
| | - Veronika Mickova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic.
| | - Kamil Musilek
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic.
| | - Lucie Zemanova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic.
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4
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Bennett JP, Meek EC, Chambers JE. Reactivation by novel pyridinium oximes of rat serum and skeletal muscle acetylcholinesterase inhibited by organophosphates. J Biochem Mol Toxicol 2024; 38:e23750. [PMID: 38952032 PMCID: PMC11221569 DOI: 10.1002/jbt.23750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/05/2024] [Accepted: 05/16/2024] [Indexed: 07/03/2024]
Abstract
The treatment of organophosphate (OP) anticholinesterases currently lacks an effective oxime reactivator of OP-inhibited acetylcholinesterase (AChE) which can penetrate the blood-brain barrier (BBB). Our laboratories have synthesized novel substituted phenoxyalkyl pyridinium oximes and tested them for their ability to promote survival of rats challenged with lethal doses of nerve agent surrogates. These previous studies demonstrated the ability of some of these oximes to promote 24-h survival to rats challenged with a lethal level of highly relevant surrogates for sarin and VX. The reactivation of OP-inhibited AChE in peripheral tissues was likely to be a major contributor to their efficacy in survival of lethal OP challenges. In the present study, twenty of these novel oximes were screened in vitro for reactivation ability for AChE in rat skeletal muscle and serum using two nerve agent surrogates: phthalimidyl isopropyl methylphosphonate (PIMP, a sarin surrogate) and 4-nitrophenyl ethyl methylphosphonate (NEMP, a VX surrogate). The oximes demonstrated a range of 23%-102% reactivation of AChE in vitro across both tissue types. Some of the novel oximes tested in the present study demonstrated the ability to more effectively reactivate AChE in serum than the currently approved oxime, 2-PAM. Therefore, some of these novel oximes have the potential to reverse AChE inhibition in peripheral target tissues and contribute to survival efficacy.
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Affiliation(s)
- Joshua P Bennett
- Center for Environmental Health Sciences, College of Veterinary Medicine, Department of Comparative Biomedical Sciences, Mississippi State University, Mississippi State, Mississippi, USA
| | - Edward C Meek
- Center for Environmental Health Sciences, College of Veterinary Medicine, Department of Comparative Biomedical Sciences, Mississippi State University, Mississippi State, Mississippi, USA
| | - Janice E Chambers
- Center for Environmental Health Sciences, College of Veterinary Medicine, Department of Comparative Biomedical Sciences, Mississippi State University, Mississippi State, Mississippi, USA
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5
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Kitagawa DAS, Dos Santos MC, Kuča K, França TCC, Cavalcante SFDA. In vitro comparison of the acetylcholinesterase inhibition caused by V- and A-series nerve agents' surrogates. Chem Biol Interact 2023; 383:110678. [PMID: 37595776 DOI: 10.1016/j.cbi.2023.110678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/04/2023] [Accepted: 08/13/2023] [Indexed: 08/20/2023]
Abstract
Nerve agents (NA) pose as a great risk in the modern world. NA from the V-series, such as VX, are currently recognized as the most toxic among those compounds. However, the emergence of new classes of toxicants recently included in the Chemical Weapons Convention (CWC), such as the A-series NA, a class of organophosphorus compounds related to phosphoramidates, pose a new source of concern due to the lack of information. In order advance in the investigation on the toxicity of such toxic chemicals, we performed in vitro studies to compare representatives of the V- and A-series using affordable surrogates. Results suggest a similar inhibition potency between both agents.
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Affiliation(s)
- Daniel A S Kitagawa
- Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Brazilian Army Technological Center (CTEx), Rio de Janeiro, RJ, Brazil; Laboratory of Molecular Modeling Applied to Chemical and Biological Defense (LMACBD), Military Institute of Engineering (IME), Rio de Janeiro, Brazil.
| | - Marcelo C Dos Santos
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense (LMACBD), Military Institute of Engineering (IME), Rio de Janeiro, Brazil.
| | - Kamil Kuča
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic.
| | - Tanos C C França
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense (LMACBD), Military Institute of Engineering (IME), Rio de Janeiro, Brazil; Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic.
| | - Samir F de A Cavalcante
- Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Brazilian Army Technological Center (CTEx), Rio de Janeiro, RJ, Brazil; Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic.
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6
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Pampalakis G, Kostoudi S. Chemical, Physical, and Toxicological Properties of V-Agents. Int J Mol Sci 2023; 24:ijms24108600. [PMID: 37239944 DOI: 10.3390/ijms24108600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/07/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
V-agents are exceedingly toxic organophosphate nerve agents. The most widely known V-agents are the phosphonylated thiocholines VX and VR. Nonetheless, other V-subclasses have been synthesized. Here, a holistic overview of V-agents is provided, where these compounds have been categorized based on their structures to facilitate their study. A total of seven subclasses of V-agents have been identified, including phospho(n/r)ylated selenocholines and non-sulfur-containing agents, such as VP and EA-1576 (EA: Edgewood Arsenal). Certain V-agents have been designed through the conversion of phosphorylated pesticides to their respective phosphonylated analogs, such as EA-1576 derived from mevinphos. Further, this review provides a description of their production, physical properties, toxicity, and stability during storage. Importantly, V-agents constitute a percutaneous hazard, while their high stability ensures the contamination of the exposed area for weeks. The danger of V-agents was highlighted in the 1968 VX accident in Utah. Until now, VX has been used in limited cases of terrorist attacks and assassinations, but there is an increased concern about potential terrorist production and use. For this reason, studying the chemistry of VX and other less-studied V-agents is important to understand their properties and develop potential countermeasures.
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Affiliation(s)
- Georgios Pampalakis
- Laboratory of Pharmacology, School of Pharmacy, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Stavroula Kostoudi
- Laboratory of Pharmacology, School of Pharmacy, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
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Agarwal G, Tichenor H, Roo S, Lane TR, Ekins S, McElroy CA. Targeted Metabolomics of Organophosphate Pesticides and Chemical Warfare Nerve Agent Simulants Using High- and Low-Dose Exposure in Human Liver Microsomes. Metabolites 2023; 13:metabo13040495. [PMID: 37110155 PMCID: PMC10144572 DOI: 10.3390/metabo13040495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/21/2023] [Accepted: 03/23/2023] [Indexed: 03/31/2023] Open
Abstract
Our current understanding of organophosphorus agent (pesticides and chemical warfare nerve agents) metabolism in humans is limited to the general transformation by cytochrome P450 enzymes and, to some extent, by esterases and paraoxonases. The role of compound concentrations on the rate of clearance is not well established and is further explored in the current study. We discuss the metabolism of 56 diverse organophosphorus compounds (both pesticides and chemical warfare nerve agent simulants), many of which were explored at two variable dose regimens (high and low), determining their clearance rates (Clint) in human liver microsomes. For compounds that were soluble at high concentrations, 1D-NMR, 31P, and MRM LC-MS/MS were used to calculate the Clint and the identity of certain metabolites. The determined Clint rates ranged from 0.001 to 2245.52 µL/min/mg of protein in the lower dose regimen and from 0.002 to 98.57 µL/min/mg of protein in the high dose regimen. Though direct equivalency between the two regimens was absent, we observed (1) both mono- and bi-phasic metabolism of the OPs and simulants in the microsomes. Compounds such as aspon and formothion exhibited biphasic decay at both high and low doses, suggesting either the involvement of multiple enzymes with different KM or substrate/metabolite effects on the metabolism. (2) A second observation was that while some compounds, such as dibrom and merphos, demonstrated a biphasic decay curve at the lower concentrations, they exhibited only monophasic metabolism at the higher concentration, likely indicative of saturation of some metabolic enzymes. (3) Isomeric differences in metabolism (between Z- and E- isomers) were also observed. (4) Lastly, structural comparisons using examples of the oxon group over the original phosphorothioate OP are also discussed, along with the identification of some metabolites. This study provides initial data for the development of in silico metabolism models for OPs with broad applications.
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Affiliation(s)
- Garima Agarwal
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Hunter Tichenor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Sarah Roo
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Thomas R. Lane
- Collaborations Pharmaceutical Inc., Raleigh, NC 27606, USA
| | - Sean Ekins
- Collaborations Pharmaceutical Inc., Raleigh, NC 27606, USA
| | - Craig A. McElroy
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
- Correspondence:
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8
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Thinschmidt JS, Harden SW, King MA, Talton JD, Frazier CJ. A rapid in vitro assay for evaluating the effects of acetylcholinesterase inhibitors and reactivators in the rat basolateral amygdala. Front Cell Neurosci 2022; 16:1066312. [DOI: 10.3389/fncel.2022.1066312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 10/31/2022] [Indexed: 11/22/2022] Open
Abstract
We established a novel brain slice assay to test the ability of acetylcholinesterase (AChE) reactivators to prevent ACh-induced M1 muscarinic acetylcholine receptor (mAChR) dependent hyperexcitability observed after exposure to the organophosphate (OP)-based AChE inhibitor and sarin surrogate 4-nitrophenyl isopropyl methylphosphonate (NIMP). Whole-cell patch clamp recordings were used to evaluate the response of pyramidal neurons in the rat basolateral amygdala (BLA) to brief (1 min) bath application of ACh (100 μM), either in control conditions, or after exposure to NIMP ± an AChE reactivator. Bath application of ACh produced atropine- and pirenzepine-sensitive inward currents in voltage clamped BLA pyramidal neurons, and increased the frequency of spontaneous EPSCs, suggesting robust activation of M1 mAChRs. Responses to ACh were increased ~3–5 fold in slices that had been preincubated in NIMP, and these effects were reversed in a concentration dependent manner by exposure to a commercially available AChE reactivator. The current work outlines a simple assay that can be used to evaluate the efficacy of both known and novel AChE reactivators in an area of the limbic system that likely contributes to seizures after acute exposure to OP-based AChE inhibitors.
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9
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Santos MC, Botelho FD, Gonçalves AS, Kitagawa DAS, Borges CVN, Carvalho-Silva T, Bernardo LB, Ferreira CN, Rodrigues RB, Ferreira Neto DC, Nepovimova E, Kuča K, LaPlante SR, Lima ALS, França TCC, Cavalcante SFA. Are the current commercially available oximes capable of reactivating acetylcholinesterase inhibited by the nerve agents of the A-series? Arch Toxicol 2022; 96:2559-2572. [PMID: 35666269 DOI: 10.1007/s00204-022-03316-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 05/11/2022] [Indexed: 12/20/2022]
Abstract
The misuse of novichok agents in assassination attempts has been reported in the international media since 2018. These relatively new class of neurotoxic agents is claimed to be more toxic than the agents of the G and V series and so far, there is no report yet in literature about potential antidotes against them. To shed some light into this issue, we report here the design and synthesis of NTMGMP, a surrogate of A-242 and also the first surrogate of a novichok agent useful for experimental evaluation of antidotes. Furthermore, the efficiency of the current commercial oximes to reactivate NTMGMP-inhibited acetylcholinesterase (AChE) was evaluated. The Ellman test was used to confirm the complete inhibition of AChE, and to compare the subsequent rates of reactivation in vitro as well as to evaluate aging. In parallel, molecular docking, molecular dynamics and MM-PBSA studies were performed on a computational model of the human AChE (HssAChE)/NTMGMP complex to assess the reactivation performances of the commercial oximes in silico. Experimental and theoretical studies matched the exact hierarchy of efficiency and pointed to trimedoxime as the most promising commercial oxime for reactivation of AChE inhibited by A-242.
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Affiliation(s)
- Marcelo C Santos
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense, Military Institute of Engineering, Rio de Janeiro, Brazil
| | - Fernanda D Botelho
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense, Military Institute of Engineering, Rio de Janeiro, Brazil
| | - Arlan S Gonçalves
- Federal Institute of Education, Science and Technology of Espírito Santo - Units Vila Velha and Vitória, Vitória, ES, Brazil.,Federal University of Espírito Santo, Unit Goiabeiras, Vitória, ES, Brazil
| | - Daniel A S Kitagawa
- Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Brazilian Army Technological Center (CTEx), Rio de Janeiro, Brazil
| | - Caio V N Borges
- Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Brazilian Army Technological Center (CTEx), Rio de Janeiro, Brazil.,Chemical Engineering Department, Military Institute of Engineering, Rio de Janeiro, Brazil
| | - Taynara Carvalho-Silva
- Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Brazilian Army Technological Center (CTEx), Rio de Janeiro, Brazil.,Chemical Engineering Department, Military Institute of Engineering, Rio de Janeiro, Brazil
| | - Leandro B Bernardo
- Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Brazilian Army Technological Center (CTEx), Rio de Janeiro, Brazil.,Chemical Engineering Department, Military Institute of Engineering, Rio de Janeiro, Brazil
| | - Cíntia N Ferreira
- Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Brazilian Army Technological Center (CTEx), Rio de Janeiro, Brazil
| | - Rafael B Rodrigues
- Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Brazilian Army Technological Center (CTEx), Rio de Janeiro, Brazil
| | - Denise C Ferreira Neto
- Chemical Engineering Department, Military Institute of Engineering, Rio de Janeiro, Brazil
| | - Eugenie Nepovimova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Kamil Kuča
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Steven R LaPlante
- Université de Québec, INRS-Centre Armand-Frappier Santé Biotechnologie, Laval, Québec, H7V 1B7, Canada
| | - Antonio L S Lima
- Chemical Engineering Department, Military Institute of Engineering, Rio de Janeiro, Brazil
| | - Tanos C C França
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense, Military Institute of Engineering, Rio de Janeiro, Brazil. .,Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic. .,Université de Québec, INRS-Centre Armand-Frappier Santé Biotechnologie, Laval, Québec, H7V 1B7, Canada.
| | - Samir F A Cavalcante
- Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Brazilian Army Technological Center (CTEx), Rio de Janeiro, Brazil. .,Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic.
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10
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François S, Mondot S, Gerard Q, Bel R, Knoertzer J, Berriche A, Cavallero S, Baati R, Orset C, Dal Bo G, Thibault K. Long-Term Anxiety-Like Behavior and Microbiota Changes Induced in Mice by Sublethal Doses of Acute Sarin Surrogate Exposure. Biomedicines 2022; 10:biomedicines10051167. [PMID: 35625901 PMCID: PMC9138233 DOI: 10.3390/biomedicines10051167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/07/2022] [Accepted: 05/16/2022] [Indexed: 12/10/2022] Open
Abstract
Anxiety disorder is one of the most reported complications following organophosphorus (OP) nerve agent (NA) exposure. The goal of this study was to characterize the long-term behavioral impact of a single low dose exposure to 4-nitrophenyl isopropyl methylphosphonate (NIMP), a sarin surrogate. We chose two different sublethal doses of NIMP, each corresponding to a fraction of the median lethal dose (one mild and one convulsive), and evaluated behavioral changes over a 6-month period following exposure. Mice exposed to both doses showed anxious behavior which persisted for six-months post-exposure. A longitudinal magnetic resonance imaging examination did not reveal any anatomical changes in the amygdala throughout the 6-month period. While no cholinesterase activity change or neuroinflammation could be observed at the latest timepoint in the amygdala of NIMP-exposed mice, important modifications in white blood cell counts were noted, reflecting a perturbation of the systemic immune system. Furthermore, intestinal inflammation and microbiota changes were observed at 6-months in NIMP-exposed animals regardless of the dose received. This is the first study to identify long-term behavioral impairment, systemic homeostasis disorganization and gut microbiota alterations following OP sublethal exposure. Our findings highlight the importance of long-term care for victims of NA exposure, even in asymptomatic cases.
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Affiliation(s)
- Sabine François
- Department of Radiation Biological Effects, Armed Forces Biomedical Research Institute, 91220 Bretigny sur Orge, France; (S.F.); (S.C.)
| | - Stanislas Mondot
- Micalis Institute, AgroParisTech, Université Paris-Saclay, INRAE, 78350 Jouy-en-Josas, France;
| | - Quentin Gerard
- Department of Toxicology and Chemical Risks, Armed Forces Biomedical Research Institute, 91220 Bretigny sur Orge, France; (Q.G.); (R.B.); (J.K.); (A.B.)
- Institut Blood and Brain@caen-normandie Cyceron, Caen-Normandie University, UNICAEN, INSERM, UMR-S U1237, Physiopathology and Imaging of Neurological Disorders (PhIND), 14000 Caen, France;
| | - Rosalie Bel
- Department of Toxicology and Chemical Risks, Armed Forces Biomedical Research Institute, 91220 Bretigny sur Orge, France; (Q.G.); (R.B.); (J.K.); (A.B.)
| | - Julie Knoertzer
- Department of Toxicology and Chemical Risks, Armed Forces Biomedical Research Institute, 91220 Bretigny sur Orge, France; (Q.G.); (R.B.); (J.K.); (A.B.)
| | - Asma Berriche
- Department of Toxicology and Chemical Risks, Armed Forces Biomedical Research Institute, 91220 Bretigny sur Orge, France; (Q.G.); (R.B.); (J.K.); (A.B.)
- CEA, 92260 Fontenay aux Roses, France
| | - Sophie Cavallero
- Department of Radiation Biological Effects, Armed Forces Biomedical Research Institute, 91220 Bretigny sur Orge, France; (S.F.); (S.C.)
| | - Rachid Baati
- ICPEES UMR CNRS 7515, Institut de Chimie des Procédés, pour l’Energie, l’Environnement, et la Santé, 67000 Strasbourg, France;
| | - Cyrille Orset
- Institut Blood and Brain@caen-normandie Cyceron, Caen-Normandie University, UNICAEN, INSERM, UMR-S U1237, Physiopathology and Imaging of Neurological Disorders (PhIND), 14000 Caen, France;
| | - Gregory Dal Bo
- Department of Toxicology and Chemical Risks, Armed Forces Biomedical Research Institute, 91220 Bretigny sur Orge, France; (Q.G.); (R.B.); (J.K.); (A.B.)
- Correspondence: (G.D.B.); (K.T.)
| | - Karine Thibault
- Department of Toxicology and Chemical Risks, Armed Forces Biomedical Research Institute, 91220 Bretigny sur Orge, France; (Q.G.); (R.B.); (J.K.); (A.B.)
- Correspondence: (G.D.B.); (K.T.)
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11
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Kohoutova Z, Malinak D, Andrys R, Svobodova J, Psotka M, Schmidt M, Prchal L, Musilek K. Charged pyridinium oximes with thiocarboxamide moiety are equally or less effective reactivators of organophosphate-inhibited cholinesterases compared to analogous carboxamides. J Enzyme Inhib Med Chem 2022; 37:760-767. [PMID: 35193448 PMCID: PMC8881075 DOI: 10.1080/14756366.2022.2041628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The organophosphorus antidotes, so-called oximes, are able to restore the enzymatic function of acetylcholinesterase (AChE) or butyrylcholinesterase (BChE) via cleavage of organophosphate from the active site of the phosphylated enzyme. In this work, the charged pyridinium oximes containing thiocarboxamide moiety were designed, prepared and tested. Their stability and pKa properties were found to be analogous to parent carboxamides (K027, K048 and K203). The inhibitory ability of thiocarboxamides was found in low µM levels for AChE and high µM levels for BChE. Their reactivation properties were screened on human recombinant AChE and BChE inhibited by nerve agent surrogates and paraoxon. One thiocarboxamide was able to effectively restore function of NEMP- and NEDPA-AChE, whereas two thiocarboxamides were able to reactivate BChE inhibited by all tested organophosphates. These results were confirmed by reactivation kinetics, where thiocarboxamides were proved to be effective, but less potent reactivators if compared to carboxamides.
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Affiliation(s)
- Zuzana Kohoutova
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - David Malinak
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Biomedical Research Centre, University Hospital in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Rudolf Andrys
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Jana Svobodova
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Miroslav Psotka
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Biomedical Research Centre, University Hospital in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Monika Schmidt
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Biomedical Research Centre, University Hospital in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Lukas Prchal
- Biomedical Research Centre, University Hospital in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Kamil Musilek
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Biomedical Research Centre, University Hospital in Hradec Kralove, Hradec Kralove, Czech Republic
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12
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Dubrana LE, Knoll-Gellida A, Bourcier LM, Mercé T, Pedemay S, Nachon F, Calas AG, Baati R, Soares M, Babin PJ. An Antidote Screening System for Organophosphorus Poisoning Using Zebrafish Larvae. ACS Chem Neurosci 2021; 12:2865-2877. [PMID: 34284583 DOI: 10.1021/acschemneuro.1c00251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Organophosphorus (OP) cholinesterase inhibitors, which include insecticides and chemical warfare nerve agents, are very potent neurotoxicants. Given that the actual treatment has several limitations, the present study provides a general method, called the zebrafish-OP-antidote test (ZOAT), and basic scientific data, to identify new antidotes that are more effective than the reference pyridinium oximes after acute OP poisoning. The reactivation capacity of a chemical compound can be measured using in vivo and ex vivo acetylcholinesterase (AChE) assays. We demonstrated that it is possible to differentiate between chemical compound protective efficacies in the central and peripheral nervous system via the visual motor response and electric field pulse motor response tests, respectively. Moreover, the ability to cross the brain-blood barrier can be estimated in a physiological context by combining an AChE assay on the head and trunk-tail fractions and the cellular and tissue localization of AChE activity in the whole-mount animal. ZOAT is an innovative method suitable for the screening and rapid identification of chemicals and mixtures used as antidote for OP poisoning. The method will make it easier to identify more effective medical countermeasures for chemical threat agents, including combinatorial therapies.
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Affiliation(s)
- Leslie E. Dubrana
- Department of Life and Health Sciences, INSERM, Maladies Rares: Génétique et Métabolisme (MRGM), U1211, Université de Bordeaux, Pessac, F-33615, France
| | - Anja Knoll-Gellida
- Department of Life and Health Sciences, INSERM, Maladies Rares: Génétique et Métabolisme (MRGM), U1211, Université de Bordeaux, Pessac, F-33615, France
| | - Laure M. Bourcier
- Department of Life and Health Sciences, INSERM, Maladies Rares: Génétique et Métabolisme (MRGM), U1211, Université de Bordeaux, Pessac, F-33615, France
| | - Théo Mercé
- Department of Life and Health Sciences, INSERM, Maladies Rares: Génétique et Métabolisme (MRGM), U1211, Université de Bordeaux, Pessac, F-33615, France
| | - Sandra Pedemay
- Department of Life and Health Sciences, INSERM, Maladies Rares: Génétique et Métabolisme (MRGM), U1211, Université de Bordeaux, Pessac, F-33615, France
| | - Florian Nachon
- Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armés, Brétigny sur Orge, F-91220, France
| | - André-Guilhem Calas
- Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armés, Brétigny sur Orge, F-91220, France
| | - Rachid Baati
- ECPM UMR CNRS 7515, ICPEES Institut de Chimie et Procédés pour l’Énergie, l’Environnement et la Santé, Strasbourg, F-67087, France
| | - Magalie Soares
- Department of Life and Health Sciences, INSERM, Maladies Rares: Génétique et Métabolisme (MRGM), U1211, Université de Bordeaux, Pessac, F-33615, France
| | - Patrick J. Babin
- Department of Life and Health Sciences, INSERM, Maladies Rares: Génétique et Métabolisme (MRGM), U1211, Université de Bordeaux, Pessac, F-33615, France
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13
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Bennion BJ, Malfatti MA, Be NA, Enright HA, Hok S, Cadieux CL, Carpenter TS, Lao V, Kuhn EA, McNerney MW, Lightstone FC, Nguyen TH, Valdez CA. Development of a CNS-permeable reactivator for nerve agent exposure: an iterative, multi-disciplinary approach. Sci Rep 2021; 11:15567. [PMID: 34330964 PMCID: PMC8324913 DOI: 10.1038/s41598-021-94963-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 07/19/2021] [Indexed: 11/09/2022] Open
Abstract
Nerve agents have experienced a resurgence in recent times with their use against civilian targets during the attacks in Syria (2012), the poisoning of Sergei and Yulia Skripal in the United Kingdom (2018) and Alexei Navalny in Russia (2020), strongly renewing the importance of antidote development against these lethal substances. The current standard treatment against their effects relies on the use of small molecule-based oximes that can efficiently restore acetylcholinesterase (AChE) activity. Despite their efficacy in reactivating AChE, the action of drugs like 2-pralidoxime (2-PAM) is primarily limited to the peripheral nervous system (PNS) and, thus, provides no significant protection to the central nervous system (CNS). This lack of action in the CNS stems from their ionic nature that, on one end makes them very powerful reactivators and on the other renders them ineffective at crossing the Blood Brain Barrier (BBB) to reach the CNS. In this report, we describe the use of an iterative approach composed of parallel chemical and in silico syntheses, computational modeling, and a battery of detailed in vitro and in vivo assays that resulted in the identification of a promising, novel CNS-permeable oxime reactivator. Additional experiments to determine acute and chronic toxicity are ongoing.
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Affiliation(s)
- Brian J Bennion
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Michael A Malfatti
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Nicholas A Be
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Heather A Enright
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Saphon Hok
- Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
- Forensic Science Center, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - C Linn Cadieux
- United States Army Medical Research Institute of Chemical Defense, Aberdeen, MD, 21010, USA
| | - Timothy S Carpenter
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Victoria Lao
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Edward A Kuhn
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - M Windy McNerney
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
- Affiliation: Mental Illness Research, Education and Clinical Center, Veterans Affairs, Palo Alto, CA, 94304, USA
- Affiliation: Department of Psychiatry, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Felice C Lightstone
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Tuan H Nguyen
- Global Security Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Carlos A Valdez
- Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
- Forensic Science Center, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
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14
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Lee HM, Andrys R, Jonczyk J, Kim K, Vishakantegowda AG, Malinak D, Skarka A, Schmidt M, Vaskova M, Latka K, Bajda M, Jung YS, Malawska B, Musilek K. Pyridinium-2-carbaldoximes with quinolinium carboxamide moiety are simultaneous reactivators of acetylcholinesterase and butyrylcholinesterase inhibited by nerve agent surrogates. J Enzyme Inhib Med Chem 2021; 36:437-449. [PMID: 33467931 PMCID: PMC7822067 DOI: 10.1080/14756366.2020.1869954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The pyridinium-2-carbaldoximes with quinolinium carboxamide moiety were designed and synthesised as cholinesterase reactivators. The prepared compounds showed intermediate-to-high inhibition of both cholinesterases when compared to standard oximes. Their reactivation ability was evaluated in vitro on human recombinant acetylcholinesterase (hrAChE) and human recombinant butyrylcholinesterase (hrBChE) inhibited by nerve agent surrogates (NIMP, NEMP, and NEDPA) or paraoxon. In the reactivation screening, one compound was able to reactivate hrAChE inhibited by all used organophosphates and two novel compounds were able to reactivate NIMP/NEMP-hrBChE. The reactivation kinetics revealed compound 11 that proved to be excellent reactivator of paraoxon-hrAChE better to obidoxime and showed increased reactivation of NIMP/NEMP-hrBChE, although worse to obidoxime. The molecular interactions of studied reactivators were further identified by in silico calculations. Molecular modelling results revealed the importance of creation of the pre-reactivation complex that could lead to better reactivation of both cholinesterases together with reducing particular interactions for lower intrinsic inhibition by the oxime.
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Affiliation(s)
- Hyun Myung Lee
- Division of Bio and Drug Discovery, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea.,Department of Medicinal Chemistry and Pharmacology, Daejeon, Republic of Korea
| | - Rudolf Andrys
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Jakub Jonczyk
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland
| | - Kyuneun Kim
- Division of Bio and Drug Discovery, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea.,Department of Medicinal Chemistry and Pharmacology, Daejeon, Republic of Korea
| | - Avinash G Vishakantegowda
- Division of Bio and Drug Discovery, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea.,Department of Medicinal Chemistry and Pharmacology, Daejeon, Republic of Korea
| | - David Malinak
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Adam Skarka
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Monika Schmidt
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Michaela Vaskova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Kamil Latka
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland
| | - Marek Bajda
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland
| | - Young-Sik Jung
- Division of Bio and Drug Discovery, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea.,Department of Medicinal Chemistry and Pharmacology, Daejeon, Republic of Korea
| | - Barbara Malawska
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland
| | - Kamil Musilek
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
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15
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Kitagawa DAS, Rodrigues RB, Silva TN, Dos Santos WV, da Rocha VCV, de Almeida JSFD, Bernardo LB, Carvalho-Silva T, Ferreira CN, da Silva AAT, Simas ABC, Nepovimova E, Kuča K, França TCC, Cavalcante SFDA. Design, synthesis, in silico studies and in vitro evaluation of isatin-pyridine oximes hybrids as novel acetylcholinesterase reactivators. J Enzyme Inhib Med Chem 2021; 36:1370-1377. [PMID: 34148470 PMCID: PMC8219220 DOI: 10.1080/14756366.2021.1916009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Organophosphorus poisoning caused by some pesticides and nerve agents is a life-threating condition that must be swiftly addressed to avoid casualties. Despite the availability of medical countermeasures, the clinically available compounds lack a broad spectrum, are not effective towards all organophosphorus toxins, and have poor pharmacokinetics properties to allow them crossing the blood-brain barrier, hampering cholinesterase reactivation at the central nervous system. In this work, we designed and synthesised novel isatin derivatives, linked to a pyridinium 4-oxime moiety by an alkyl chain with improved calculated properties, and tested their reactivation potency against paraoxon- and NEMP-inhibited acetylcholinesterase in comparison to the standard antidote pralidoxime. Our results showed that these compounds displayed comparable in vitro reactivation also pointed by the in silico studies, suggesting that they are promising compounds to tackle organophosphorus poisoning.
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Affiliation(s)
- Daniel A S Kitagawa
- Laboratory of Molecular Modelling Applied to Chemical and Biological Defense (LMACBD), Military Institute of Engineering (IME), Rio de Janeiro, Brazil.,Brazilian Army Technological Center (CTEx), Institute of CBRN Defense (IDQBRN), Rio de Janeiro, Brazil
| | - Rafael B Rodrigues
- Brazilian Army Technological Center (CTEx), Institute of CBRN Defense (IDQBRN), Rio de Janeiro, Brazil
| | - Thiago N Silva
- School of Pharmacy, Universidade Castelo Branco (UCB), Rio de Janeiro, Brazil
| | - Wellington V Dos Santos
- Emergency and Rescue Department (DSE), Rio de Janeiro State Fire Department (CBMERJ), Rio de Janeiro, Brazil.,Universidade Estácio de Sá (UNESA), Rio de Janeiro, Brazil
| | - Vinicius C V da Rocha
- Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, Nilópolis, Brazil
| | - Joyce S F D de Almeida
- Laboratory of Molecular Modelling Applied to Chemical and Biological Defense (LMACBD), Military Institute of Engineering (IME), Rio de Janeiro, Brazil
| | - Leandro B Bernardo
- Brazilian Army Technological Center (CTEx), Institute of CBRN Defense (IDQBRN), Rio de Janeiro, Brazil
| | - Taynara Carvalho-Silva
- Brazilian Army Technological Center (CTEx), Institute of CBRN Defense (IDQBRN), Rio de Janeiro, Brazil
| | - Cintia N Ferreira
- Brazilian Army Technological Center (CTEx), Institute of CBRN Defense (IDQBRN), Rio de Janeiro, Brazil
| | - Angelo A T da Silva
- Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, Nilópolis, Brazil
| | - Alessandro B C Simas
- Instituto de Pesquisas de Produtos Naturais Walter Mors (IPPN), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Eugenie Nepovimova
- Department of Chemistry, Faculty of Science, University of Hradec Králové, Hradec Králové, Czech Republic
| | - Kamil Kuča
- Department of Chemistry, Faculty of Science, University of Hradec Králové, Hradec Králové, Czech Republic
| | - Tanos C C França
- Laboratory of Molecular Modelling Applied to Chemical and Biological Defense (LMACBD), Military Institute of Engineering (IME), Rio de Janeiro, Brazil.,Department of Chemistry, Faculty of Science, University of Hradec Králové, Hradec Králové, Czech Republic
| | - Samir F de A Cavalcante
- Brazilian Army Technological Center (CTEx), Institute of CBRN Defense (IDQBRN), Rio de Janeiro, Brazil.,School of Pharmacy, Universidade Castelo Branco (UCB), Rio de Janeiro, Brazil.,Instituto de Pesquisas de Produtos Naturais Walter Mors (IPPN), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.,Department of Chemistry, Faculty of Science, University of Hradec Králové, Hradec Králové, Czech Republic
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16
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Figueroa-Villar JD, Petronilho EC, Kuca K, Franca TCC. Review about Structure and Evaluation of Reactivators of Acetylcholinesterase Inhibited with Neurotoxic Organophosphorus Compounds. Curr Med Chem 2021; 28:1422-1442. [PMID: 32334495 DOI: 10.2174/0929867327666200425213215] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 03/08/2020] [Accepted: 04/01/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Neurotoxic chemical warfare agents can be classified as some of the most dangerous chemicals for humanity. The most effective of those agents are the Organophosphates (OPs) capable of restricting the enzyme Acetylcholinesterase (AChE), which in turn, controls the nerve impulse transmission. When AChE is inhibited by OPs, its reactivation can be usually performed through cationic oximes. However, until today, it has not been developed one universal defense agent, with complete effective reactivation activity for AChE inhibited by any of the many types of existing neurotoxic OPs. For this reason, before treating people intoxicated by an OP, it is necessary to determine the neurotoxic compound that was used for contamination, in order to select the most effective oxime. Unfortunately, this task usually requires a relatively long time, raising the possibility of death. Cationic oximes also display a limited capacity of permeating the Blood-Brain Barrier (BBB). This fact compromises their capacity to reactivating AChE inside the nervous system. METHODS We performed a comprehensive search on the data about OPs available on the scientific literature today in order to cover all the main drawbacks still faced in the research for the development of effective antidotes against those compounds. RESULTS Therefore, this review about neurotoxic OPs and the reactivation of AChE, provides insights for the new agents' development. The most expected defense agent is a molecule without toxicity and effective to reactivate AChE inhibited by all neurotoxic OPs. CONCLUSION To develop these new agents, the application of diverse scientific areas of research, especially theoretical procedures as computational science (computer simulation, docking and dynamics), organic synthesis, spectroscopic methodologies, biology, biochemical and biophysical information, medicinal chemistry, pharmacology and toxicology, is necessary.
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Affiliation(s)
- José Daniel Figueroa-Villar
- Medicinal Chemistry Group, Department of Chemical Engineering, Military Institute of Engineering, 22270- 090, Rio de Janeiro, Brazil
| | - Elaine C Petronilho
- Medicinal Chemistry Group, Department of Chemical Engineering, Military Institute of Engineering, 22270- 090, Rio de Janeiro, Brazil
| | - Kamil Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Králové 50003, Czech Republic
| | - Tanos C C Franca
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Králové 50003, Czech Republic
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17
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Angrand L, Takillah S, Malissin I, Berriche A, Cervera C, Bel R, Gerard Q, Knoertzer J, Baati R, Kononchik JP, Megarbane B, Thibault K, Dal Bo G. Persistent brainwave disruption and cognitive impairment induced by acute sarin surrogate sub-lethal dose exposure. Toxicology 2021; 456:152787. [PMID: 33887375 DOI: 10.1016/j.tox.2021.152787] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/11/2021] [Accepted: 04/15/2021] [Indexed: 11/15/2022]
Abstract
Warfare neurotoxicants such as sarin, soman or VX, are organophosphorus compounds which irreversibly inhibit cholinesterase. High-dose exposure with nerve agents (NA) is known to produce seizure activity and related brain damage, while less is known about the effects of acute sub-lethal dose exposure. The aim of this study was to characterize behavioral, brain activity and neuroinflammatory modifications at different time points after exposure to 4-nitrophenyl isopropyl methylphosphonate (NIMP), a sarin surrogate. In order to decipher the impacts of sub-lethal exposure, we chose 4 different doses of NIMP each corresponding to a fraction of the median lethal dose (LD50). First, we conducted a behavioral analysis of symptoms during the first hour following NIMP challenge and established a specific scoring scale for the intoxication severity. The intensity of intoxication signs was dose-dependent and proportional to the cholinesterase activity inhibition evaluated in mice brain. The lowest dose (0.3 LD50) did not induce significant behavioral, electrocorticographic (ECoG) nor cholinesterase activity changes. Animals exposed to one of the other doses (0.5, 0.7 and 0.9 LD50) exhibited substantial changes in behavior, significant cholinesterase activity inhibition, and a disruption of brainwave distribution that persisted in a dose-dependent manner. To evaluate long lasting changes, we conducted ECoG recording for 30 days on mice exposed to 0.5 or 0.9 LD50 of NIMP. Mice in both groups showed long-lasting impairment of theta rhythms, and a lack of restoration in hippocampal ChE activity after 1-month post-exposure. In addition, an increase in neuroinflammatory markers (IBA-1, TNF-α, NF-κB) and edema were transiently observed in mice hippocampus. Furthermore, a novel object recognition test showed an alteration of short-term memory in both groups, 1-month post-NIMP intoxication. Our findings identified both transient and long-term ECoG alterations and some long term cognitive impairments following exposure to sub-lethal doses of NIMP. These may further impact morphopathological alterations in the brain.
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Affiliation(s)
- Loïc Angrand
- Departement of Toxicology and Chemical Risks, French Armed Forces Biomedical Research Institute, Bretigny sur Orge, France; EnvA, IMRB, Maisons-Alfort, France; Université Paris-Est Créteil, INSERM, Team Relaix, Créteil, France
| | - Samir Takillah
- Departement of Neuroscience, Unit of Fatigue and Vigilance, French Armed Forces Biomedical Research Institute, Bretigny sur Orge, France; VIFASOM Team (EA 7330), Paris Descartes University, Sorbonne Paris Cité, Hôtel Dieu, Paris, France
| | - Isabelle Malissin
- Department of Medical and Toxicological Critical Care, Lariboisière Hospital, Federation of Toxicology APHP, Paris-Diderot University, INSERM UMRS-1144, Paris, France
| | - Asma Berriche
- Departement of Toxicology and Chemical Risks, French Armed Forces Biomedical Research Institute, Bretigny sur Orge, France; CEA, Fontenay aux roses, France
| | - Chloe Cervera
- Departement of Toxicology and Chemical Risks, French Armed Forces Biomedical Research Institute, Bretigny sur Orge, France
| | - Rosalie Bel
- Departement of Toxicology and Chemical Risks, French Armed Forces Biomedical Research Institute, Bretigny sur Orge, France
| | - Quentin Gerard
- Departement of Toxicology and Chemical Risks, French Armed Forces Biomedical Research Institute, Bretigny sur Orge, France; Normandie University, UNICAEN, INSERM, GIP Cyceron, Institut Blood and Brain @Caen-Normandie (BB@C), UMR-S U1237, Physiopathology and Imaging of Neurological Disorders (PhIND), Caen, France
| | - Julie Knoertzer
- Departement of Toxicology and Chemical Risks, French Armed Forces Biomedical Research Institute, Bretigny sur Orge, France
| | - Rachid Baati
- ICPEES UMR CNRS 7515, Institut de Chimie des Procédés, pour l'Energie, l'Environnement, et la Santé, Strasbourg, France
| | - Joseph P Kononchik
- Departement of Toxicology and Chemical Risks, French Armed Forces Biomedical Research Institute, Bretigny sur Orge, France
| | - Bruno Megarbane
- VIFASOM Team (EA 7330), Paris Descartes University, Sorbonne Paris Cité, Hôtel Dieu, Paris, France; Department of Medical and Toxicological Critical Care, Lariboisière Hospital, Federation of Toxicology APHP, Paris-Diderot University, INSERM UMRS-1144, Paris, France
| | - Karine Thibault
- Departement of Toxicology and Chemical Risks, French Armed Forces Biomedical Research Institute, Bretigny sur Orge, France.
| | - Gregory Dal Bo
- Departement of Toxicology and Chemical Risks, French Armed Forces Biomedical Research Institute, Bretigny sur Orge, France.
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18
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Meek EC, Carr RL, Chambers JE. In vitro age-related differences in rats to organophosphates. Toxicol In Vitro 2021; 72:105102. [PMID: 33497710 PMCID: PMC7928206 DOI: 10.1016/j.tiv.2021.105102] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/08/2021] [Accepted: 01/20/2021] [Indexed: 02/05/2023]
Abstract
The mechanism of toxic action for organophosphates (OPs) is the persistent inhibition of acetylcholinesterase (AChE) resulting in accumulation of acetylcholine and subsequent hyperstimulation of the nervous system. Organophosphates display a wide range of acute toxicities. Differences in the OP's chemistries results in differences in the compound's metabolism and toxicity. Acute toxicities of OPs appear to be principally dependent on compound specific efficiencies of detoxication, and less dependent upon efficiencies of bioactivation and sensitivity of AChE. Serine esterases, such as carboxylesterase (CaE) and butyrylcholinesterase (BChE), play a prominent role in OP detoxication. Organophosphates can stoichiometrically inhibit these enzymes, removing OPs from circulation thus providing protection for the target enzyme, AChE. This in vitro study investigated age-related sensitivity of AChE, BChE and CaE to twelve structurally different OPs in rat tissues. Sensitivity of esterases to these OPs was assessed by inhibitory concentration 50s (IC50s). The OPs displayed a wide range of inhibitory potency toward AChE with IC50s in the low nM-μM range with no differences among ages; however, the CaE IC50s generally increased with age reflecting greater protection in adults. These results suggest age-related differences in acute toxicities of OPs in mammals are primarily a result of their detoxication capacities.
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Affiliation(s)
- Edward C Meek
- Center for Environmental Health Sciences and Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, United States of America.
| | - Russell L Carr
- Center for Environmental Health Sciences and Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, United States of America.
| | - Janice E Chambers
- Center for Environmental Health Sciences and Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, United States of America.
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19
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Dail ME, Brino MLM, Chambers JE. Effects of novel brain-penetrating oxime acetylcholinesterase reactivators on sarin surrogate-induced changes in rat brain gene expression. J Biochem Mol Toxicol 2021; 35:1-10. [PMID: 33682265 DOI: 10.1002/jbt.22755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/28/2021] [Accepted: 02/24/2021] [Indexed: 11/11/2022]
Abstract
Past assassinations and terrorist attacks demonstrate the need for a more effective antidote against nerve agents and other organophosphates (OP) that cause brain damage through inhibition of acetylcholinesterase (AChE). Our lab has invented a platform of phenoxyalkyl pyridinium oximes (US patent 9,277,937) that demonstrate the ability to cross the blood-brain barrier in in vivo rat tests with a sarin surrogate nitrophenyl isopropyl methylphosphonate (NIMP) and provide evidence of brain penetration by reducing cessation time of seizure-like behaviors, accumulation of glial fibrillary acidic protein (GFAP), and hippocampal neuropathology, as opposed to the currently approved oxime, 2-pyridine aldoxime methyl chloride (2-PAM). Using two of the novel oximes (Oximes 1 and 20), this project examined whether gene expression changes might help explain this protection. Expression changes in the piriform cortex were examined using polymerase chain reaction arrays for inflammatory cytokines and receptors. The hippocampus was examined via quantitative polymerase chain reaction for the expression of immediate-early genes involved in brain repair (Bdnf), increasing neurotoxicity (Fos), and apoptosis control (Jdp2, Bcl2l1, Bcl2l11). In the piriform cortex, NIMP significantly stimulated expression for the macrophage inflammatory proteins CCL4, IL-1A, and IL-1B. Oxime 20 by itself elicited the most changes. When it was given therapeutically post-NIMP, the largest change occurred: a 310-fold repression of the inflammatory cytokine, CCL12. In the hippocampus, NIMP increased the expression of the neurotoxicity marker Fos and decreased the expression of neuroprotective Bdnf and antiapoptotic Bcl2l1. Compared with 2-PAM, Oxime 20 stimulated Bcl2l1 expression more and returned expression closer to the vehicle control values.
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Affiliation(s)
- Mary E Dail
- Department of Comparative Biomedical Sciences, Center for Environmental Health Sciences, Mississippi State University, College of Veterinary Medicine, Mississippi State, United States, USA
| | - Meghan L M Brino
- Department of Comparative Biomedical Sciences, Center for Environmental Health Sciences, Mississippi State University, College of Veterinary Medicine, Mississippi State, United States, USA
| | - Janice E Chambers
- Department of Comparative Biomedical Sciences, Center for Environmental Health Sciences, Mississippi State University, College of Veterinary Medicine, Mississippi State, United States, USA
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20
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Nichols RH, Chambers JE. Reactivation of organophosphate-inhibited serum butyrylcholinesterase by novel substituted phenoxyalkyl pyridinium oximes and traditional oximes. Toxicology 2021; 452:152719. [PMID: 33592259 DOI: 10.1016/j.tox.2021.152719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/30/2021] [Accepted: 02/09/2021] [Indexed: 10/22/2022]
Abstract
Organophosphorus compounds (OPs) include nerve agents and insecticides that potently inhibit acetylcholinesterase (AChE), an essential enzyme found throughout the nervous system. High exposure levels to OPs lead to seizures, cardiac arrest, and death if left untreated. Oximes are a critical piece to the therapeutic regimen which remove the OP from the inhibited AChE and restore normal cholinergic function. The current oximes 2-PAM, MMB-4, TMB-4, HI-6, and obidoxime (OBD) have two drawbacks: lack of broad spectrum protection against multiple OP structures and poor brain penetration to protect against OP central neurotoxicity. An alternative strategy to enhance therapy is reactivation of serum butyrylcholinesterase (BChE). BChE is stoichiometrically inhibited by OPs with no apparent toxic result. Inhibition of BChE in the serum followed by reactivation could create a pseudo-catalytic scavenger allowing numerous regenerations of BChE to detoxify circulating OP molecules before they can reach target AChE. BChE in serum from rats, guinea pigs or humans was screened for the reactivation potential of our novel substituted phenoxyalkyl pyridinium oximes, plus 2-PAM, MMB-4, TMB-4, HI-6, and OBD (100μM) in vitro after inhibition by highly relevant surrogates of sarin, VX, and cyclosarin, and also DFP, and the insecticidal active metabolites paraoxon, phorate-oxon, and phorate-oxon sulfoxide. Novel oxime 15 demonstrated significant broad spectrum reactivation of OP-inhibited rat serum BChE while novel oxime 20 demonstrated significant broad spectrum reactivation of OP-inhibited human serum BChE. All tested oximes were poor reactivators of OP-inhibited guinea pig serum BChE. The bis-pyridinium oximes were poor BChE reactivators overall. BChE reactivation may be an additional mechanism to attenuate OP toxicity and contribute to therapeutic efficacy.
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Affiliation(s)
- Royce H Nichols
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, MS, 39762, United States
| | - Janice E Chambers
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, MS, 39762, United States.
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21
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Thakur A, Patil P, Sharma A, Flora S. Advances in the Development of Reactivators for the Treatment of Organophosphorus Inhibited Cholinesterase. CURR ORG CHEM 2020. [DOI: 10.2174/1385272824999201020203544] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Organophosphorus Compounds (OPCs) are used as pesticides to control pest, as
chemical weapons in military conflict and unfortunately in the terrorist attack. These compounds
are irreversible inhibitors of acetylcholinesterase, resulting in the accumulation of
acetylcholine that leads to severe health complications which may be ended with the death of
the victim. Current antidotes used for reactivation of organophosphorus inhibited acetylcholinesterase
(OP-AChE) are not able to cross the blood-brain barrier efficiently, therefore being
incapable to reactivate OP-AChE of the central nervous system. Due to limitations with
current antidotes, there is an urgent need for new effective antidotes that could be included in
the treatment regimen of OP poisoning. In this direction, comprehensive work has been done
to improve the permeability of existing antidotes using a variety of strategies that include
synthesis of oxime bonded to peripheral site binding moiety via an alkyl, aryl, or heteroatom-containing linker, synthesis
of sugar oximes, and prodrug of 2-PAM, incorporating fluorine and chlorine in the structure of charged oximes.
Other classes of compounds such as the mannich base, N-substituted hydroxyimino acetamide, alkylating
agents, have been investigated for reactivation of OP-AChE. This review comprises the development of various
classes of reactivators with the aim of either enhancing blood-brain permeability of existing antidotes or discovering
a new class of reactivators.
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Affiliation(s)
- Ashima Thakur
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Raebareli, India
| | - Pooja Patil
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Raebareli, India
| | - Abha Sharma
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Raebareli, India
| | - S.J.S. Flora
- Pharmacology & Toxicology, National Institute of Pharmaceutical Education and Research, Raebareli, India
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22
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Hayes TR, Chao CK, Blecha JE, Huynh TL, Zinn KR, Thompson CM, Gerdes JM, VanBrocklin HF. Biological Distribution and Metabolic Profiles of Carbon-11 and Fluorine-18 Tracers of VX- and Sarin-Analogs in Sprague-Dawley Rats. Chem Res Toxicol 2020; 34:63-69. [PMID: 33373198 PMCID: PMC7818893 DOI: 10.1021/acs.chemrestox.0c00237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Organophosphorus esters (OPs) were originally developed as pesticides but were repurposed as easily manufactured, inexpensive, and highly toxic chemical warfare agents. Acute OP toxicity is primarily due to inhibition of acetylcholinesterase (AChE), an enzyme in the central and peripheral nervous system. OP inhibition of AChE can be reversed using oxime reactivators but many show poor CNS penetration, indicating a need for new clinically viable reactivators. However, challenges exist on how to best measure restored AChE activity in vivo and assess the reactivating agent efficacy. This work reports the development of molecular imaging tools using radiolabeled OP analog tracers that are less toxic to handle in the laboratory, yet inhibit AChE in a similar fashion to the actual OPs. Carbon-11 and fluorine-18 radiolabeled analog tracers of VX and sarin OP agents were prepared. Following intravenous injection in normal Sprague-Dawley rats (n = 3-4/tracer), the tracers were evaluated and compared using noninvasive microPET/CT imaging, biodistribution assay, and arterial blood analyses. All showed rapid uptake and stable retention in brain, heart, liver, and kidney tissues determined by imaging and biodistribution. Lung uptake of the sarin analog tracers was elevated, 2-fold and 4-fold higher uptake at 5 and 30 min, respectively, compared to that for the VX analog tracers. All tracers rapidly bound to red blood cells (RBC) and blood proteins as measured in the biodistribution and arterial blood samples. Analysis of the plasma soluble activity (nonprotein/cell bound activity) showed only 1-6% parent tracer and 88-95% of the activity in the combined solid fractions (RBC and protein bound) as early as 0.5 min post injection. Multivariate analysis of tracer production yield, molar activity, brain uptake, brain area under the curve over 0-15 min, and the amount of parent tracer in the plasma at 5 min revealed the [18F]VX analog tracer had the most favorable values for each metric. This tracer was considered the more optimal tracer relative to the other tracers studied and suitable for future in vivo OP exposure and reactivation studies.
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Affiliation(s)
- Thomas R Hayes
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California 94143, United States
| | - Chih-Kai Chao
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana 59812, United States
| | - Joseph E Blecha
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California 94143, United States
| | - Tony L Huynh
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California 94143, United States
| | - Kurt R Zinn
- Departments of Radiology, Small Animal Clinical Sciences, and Biomedical Engineering; Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, Michigan 48824, United States
| | - Charles M Thompson
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana 59812, United States
| | - John M Gerdes
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana 59812, United States
| | - Henry F VanBrocklin
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, California 94143, United States
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23
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Garcia JM, Meek EC, Chambers JE. Novel pyridinium oximes enhance 24-h survivability against a lethal dose of nerve agent surrogate in adult female rats. Toxicology 2020; 446:152626. [PMID: 33159982 DOI: 10.1016/j.tox.2020.152626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/08/2020] [Accepted: 11/01/2020] [Indexed: 02/06/2023]
Abstract
Our laboratory has developed novel substituted phenoxyalkyl pyridinium oximes (US Patent 9,227,937) designed to more efficiently penetrate the central nervous system to enhance survivability and attenuate seizure-like signs and neuropathology. Previous studies with male Sprague-Dawley rats indicated that survivability was enhanced against the nerve agent (sarin) surrogate, 4-nitrophenyl isopropyl methylphosphonate (NIMP). In this study, female adult Sprague-Dawley rats, tested specifically in diestrus, were challenged subcutaneously with lethal concentrations of NIMP (0.6 mg/kg). After development of seizure-like behavior and other signs of cholinergic toxicity, human equivalent dosages of atropine (0.65 mg/kg) and one of four oximes (2-PAM, or novel oxime 15, 20, or 55; 0.146 mmol/kg) or Multisol vehicle was administered alone or in binary oxime combinations intramuscularly. Animals were closely monitored for signs of cholinergic toxicity and 24 h survivability. Percentages of animals surviving the 24 h NIMP challenge dose were 35 % for 2-PAM and 55 %, 70 %, and 25 % for novel oximes 15, 20, and 55, respectively. Improvements in survival were also observed over 2-PAM alone with binary combinations of 2-PAM and either oxime 15 or oxime 20. Additionally, administration of novel oximes decreased the duration of seizure-like behavior as compared to 2-PAM suggesting that these oximes better penetrate the blood-brain barrier to mitigate central nervous system hypercholinergic activity. Efficacies were similar between females and previously reported males. These data indicate that the novel pyridinium oximes enhance survivability against lethal OP toxicity as compared to 2-PAM in adult female rats.
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Affiliation(s)
- Jason M Garcia
- Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, P.O. Box 6100, Mississippi State, MS, 39762, USA.
| | - Edward C Meek
- Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, P.O. Box 6100, Mississippi State, MS, 39762, USA.
| | - Janice E Chambers
- Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, P.O. Box 6100, Mississippi State, MS, 39762, USA.
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24
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Talley TT, Chao CK, Berkman CE, Richardson RJ, Thompson CM. Inhibition of Acetylcholinesterases by Stereoisomeric Organophosphorus Compounds Containing Both Thioester and p-Nitrophenyl Leaving Groups. Chem Res Toxicol 2020; 33:2455-2466. [PMID: 32833441 DOI: 10.1021/acs.chemrestox.0c00236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Studies with acetylcholinesterase (AChE) inhibited by organophosphorus (OP) compounds with two chiral centers can serve as models or surrogates for understanding the rate, orientation, and postinhibitory mechanisms by the nerve agent soman that possesses dual phosphorus and carbon chiral centers. In the current approach, stereoisomers of O-methyl, [S-(succinic acid, diethyl ester), O-(4-nitrophenyl) phosphorothiolate (MSNPs) were synthesized, and the inhibition, reactivation, and aging mechanisms were studied with electric eel AChE (eeAChE) and recombinant mouse brain AChE (rmAChE). The MSNP RPRC isomer was the strongest inhibitor of both eeAChE and rmAChE at 8- and 24-fold greater potency, respectively, than the weakest SPSC isomer. eeAChE inhibited by the RPRC- or RPSC-MSNP isomer underwent spontaneous reactivation ∼10- to 20-fold faster than the enzyme inhibited by SPRC- and SPSC-MSNP, and only 4% spontaneous reactivation was observed from the SPRC-eeAChE adduct. Using 2-pyridine aldoxime methiodide (2-PAM) or trimedoxime (TMB-4), eeAChE inhibited by RPRC- or SPRC-MSNP reactivated up to 90% and 3- to 4-fold faster than eeAChE inhibited by the RPSC- or SPSC-MSNP isomer. Spontaneous reactivation rates for rmAChE were 1.5- to 10-fold higher following inhibition by RPSC- and SPSC-MSNPs than inhibition by either RC isomer, a trend opposite to that found for eeAChE. Oxime reactivation of rmAChE following inhibition by RPRC- and SPRC-MSNPs was 2.5- to 5-fold faster than inhibition by RPSC- or SPSC-MSNPs. Due to structural similarities, MSNPs that phosphylate AChE with the loss of the p-nitrophenoxy (PNP) group form identical, nonreactivatable adducts to those formed from SP-isomalathion; however, all the MSNP isomers inhibited AChE to form adducts that reactivated. Thus, MSNPs inactivate AChE via the ejection of either PNP or thiosuccinyl groups to form a combination of reactivatable and nonreactivatable adducts, and this differs from the mechanism of AChE inhibition by isomalathion.
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Affiliation(s)
- Todd T Talley
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, Montana 59812, United States
| | - Chih-Kai Chao
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, Montana 59812, United States
| | - Clifford E Berkman
- Department of Chemistry and Biochemistry, Washington State University, Pullman, Washington 99164, United States
| | - Rudy J Richardson
- Departments of Environmental Health Sciences and Neurology, University of Michigan, Ann Arbor, Michigan 48109, United States.,Center of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Charles M Thompson
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, Montana 59812, United States
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25
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Chambers JE, Dail MB, Meek EC. Oxime-mediated reactivation of organophosphate-inhibited acetylcholinesterase with emphasis on centrally-active oximes. Neuropharmacology 2020; 175:108201. [PMID: 32544483 DOI: 10.1016/j.neuropharm.2020.108201] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/02/2020] [Accepted: 06/11/2020] [Indexed: 01/25/2023]
Abstract
This review provides an overview of the global research leading to the large number of compounds developed as reactivators of acetylcholinesterase inhibited by a variety of organophosphate compounds, most of which are nerve agents but also some insecticides. A number of these organophosphates are highly toxic and effective therapy by reactivators contributes to saving lives. Two major challenges for more effective therapy with reactivators are identification of a broad spectrum reactivator efficacious against a variety of organophosphate structures, and a reactivator that can cross the blood-brain barrier to protect the brain. The most effective of the reactivators developed are the nucleophilic pyridinium oximes, which bear a permanent positive charge from the quaternary nitrogen in the pyridinium ring. The permanent positive charge retards the oximes from crossing the blood-brain barrier and therefore restoration of normal cholinergic function in the brain is unlikely. A number of laboratories have developed nucleophiles, mostly oximes, that are theorized to cross the blood-brain barrier by several strategies. At the present time, no reactivator is optimally broad spectrum across the wide group of organophosphate chemistries. Some oximes, including the substituted phenoxyalkyl pyridinium oximes invented by our laboratories, have the potential to provide neuroprotection in the brain and show evidence of efficacy against both nerve agent and insecticidal chemistries, so these novel oximes have promise for future development. This article is part of the special issue entitled 'Acetylcholinesterase Inhibitors: From Bench to Bedside to Battlefield'.
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Affiliation(s)
- Janice E Chambers
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, 39762-6100, USA.
| | - Mary B Dail
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, 39762-6100, USA
| | - Edward C Meek
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, 39762-6100, USA
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26
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Dail MB, Leach CA, Meek EC, Olivier AK, Pringle RB, Green CE, Chambers JE. Novel Brain-Penetrating Oxime Acetylcholinesterase Reactivators Attenuate Organophosphate-Induced Neuropathology in the Rat Hippocampus. Toxicol Sci 2020; 169:465-474. [PMID: 30835286 DOI: 10.1093/toxsci/kfz060] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Organophosphate (OP) anticholinesterases cause excess acetylcholine leading to seizures which, if prolonged, result in neuronal damage in the rodent brain. Novel substituted phenoxyalkyl pyridinium oximes have previously shown evidence of penetrating the rat blood-brain barrier (BBB) in in vivo tests with a sarin surrogate (nitrophenyl isopropyl methylphosphonate, NIMP) or the active metabolite of the insecticide parathion, paraoxon (PXN), by reducing the time to cessation of seizure-like behaviors and accumulation of glial fibrillary acidic protein, whereas 2-PAM did not. The neuroprotective ability of our lead oximes (15, 20, and 55) was tested using NeuN, Nissl, and Fluoro-Jade B staining in the rat hippocampus. Following lethal-level subcutaneous challenge with NIMP or PXN, rats were intramuscularly administered a novel oxime or 2-PAM plus atropine and euthanized at 4 days. There were statistically significant increases in the median damage scores of the NeuN-stained NIMP, NIMP/2-PAM, and NIMP/Oxime 15 groups compared with the control whereas the scores of the NIMP/Oxime 20 and NIMP/Oxime 55 were not significantly different from the control. The same pattern of statistical significance was observed with PXN. Nissl staining provided a similar pattern, but without statistical differences. Fluoro-Jade B indicated neuroprotection from PXN with novel oximes but not with 2-PAM. The longer blood residence times of Oximes 20 and 55 compared with Oxime 15 might have contributed to their greater efficacy. These results suggest that novel oximes 20 and 55 were able to penetrate the BBB and attenuate neuronal damage after NIMP and PXN exposure, indicating potential broad-spectrum usefulness.
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Affiliation(s)
- Mary B Dail
- *Department of Basic Sciences, Center for Environmental Health Sciences
| | - Charles A Leach
- *Department of Basic Sciences, Center for Environmental Health Sciences
| | - Edward C Meek
- *Department of Basic Sciences, Center for Environmental Health Sciences
| | - Alicia K Olivier
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi 39762
| | - Ronald B Pringle
- *Department of Basic Sciences, Center for Environmental Health Sciences
| | - Carol E Green
- Biosciences Division, SRI International, Menlo Park, California 94025
| | - Janice E Chambers
- *Department of Basic Sciences, Center for Environmental Health Sciences
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27
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Chambers JE, Meek EC. Central neuroprotection demonstrated by novel oxime countermeasures to nerve agent surrogates. Ann N Y Acad Sci 2020; 1479:5-12. [PMID: 32319115 DOI: 10.1111/nyas.14352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/20/2020] [Accepted: 03/26/2020] [Indexed: 01/09/2023]
Abstract
Oximes remain a long-standing element of the therapy for nerve agents, organophosphates (OPs) that poison by inhibiting the enzyme acetylcholinesterase (AChE), resulting in hypercholinergic activity both centrally and peripherally. Oximes, such as the pyridinium oxime pralidoxime (2-PAM) in the United States, can reactivate the inhibited AChE and restore cholinergic function. However, there are several drawbacks to the current oximes; one of them, the inability of these oximes to effectively enter the brain, is the subject of study by several laboratories, including ours. Our laboratory invented a platform of substituted phenoxyalkyl pyridinium oximes that were tested against highly relevant surrogates of the nerve agents, sarin and VX. Using high sublethal dosages of the OPs, the novel oximes were observed to attenuate seizure-like behavior in rats and to reduce the levels of glial fibrillary acidic protein (an indicator of glial scarring) to control levels, in contrast to levels observed with 2-PAM or no oxime therapy. Using lethal levels of surrogates, some novel oximes protected against lethality compared with 2-PAM, shortened the time to cessation of seizure-like behavior (from 8+ to 6 h), and protected the brain neurons. Therefore, some of these novel oximes are showing exceptional promise alone or in combination with 2-PAM as therapeutics against nerve agent toxicity.
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Affiliation(s)
- Janice E Chambers
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi
| | - Edward C Meek
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi
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28
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Pringle RB, Meek EC, Chambers HW, Chambers JE. Neuroprotection From Organophosphate-Induced Damage by Novel Phenoxyalkyl Pyridinium Oximes in Rat Brain. Toxicol Sci 2019; 166:420-427. [PMID: 30496567 DOI: 10.1093/toxsci/kfy212] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The nerve agents are extremely toxic organophosphates which lead to massive inhibition of acetylcholinesterase (AChE) in both the central and peripheral nervous systems. The currently approved pyridinium oxime reactivators of organophosphate-inhibited AChE (eg, 2-PAM in the United States) cannot penetrate the blood-brain barrier because of the permanent positive charge in the pyridinium ring. Therefore these current oximes cannot rescue inhibited AChE in the brain. Our laboratories have invented and patented a platform of substituted phenoxyalkyl pyridinium oximes that have been tested for efficacy as therapy within the brains of adult male rats which were challenged with a high sublethal dosage of highly relevant surrogates of sarin (nitrophenyl isopropyl methylphosphonate, NIMP) and VX (nitrophenyl ethyl methylphosphonate, NEMP). The histochemical astrocyte marker glial fibrillary acidic protein (GFAP) was investigated as an indication of neuropathology in two brain regions, the piriform cortex and the dentate gyrus of the hippocampus, which are regions known to be damaged by nerve agent toxicity. Rats treated with either NIMP or NEMP without therapy or with NIMP or NEMP plus 2-PAM therapy showed similar increases in GFAP compared with vehicle controls. However, the rats challenged with NIMP or NEMP plus therapy with our novel Oxime 20 (either a bromide or a mesylate salt) showed GFAP levels statistically undistinguishable from controls. These data provide highly supportive functional evidence of novel oxime entry into the brain. These novel oximes have the potential to provide central neuroprotection from organophosphate anticholinesterase-induced damage, which is a characteristic not displayed by most pyridinium oximes.
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Affiliation(s)
- Ronald B Pringle
- Center for Environmental Health Sciences.,Department of Basic Sciences, College of Veterinary Medicine
| | - Edward C Meek
- Center for Environmental Health Sciences.,Department of Basic Sciences, College of Veterinary Medicine
| | - Howard W Chambers
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, Mississippi 39762
| | - Janice E Chambers
- Center for Environmental Health Sciences.,Department of Basic Sciences, College of Veterinary Medicine
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de A. Cavalcante SF, Simas ABC, Kuča K. Nerve Agents’ Surrogates: Invaluable Tools for Development of Acetylcholinesterase Reactivators. CURR ORG CHEM 2019. [DOI: 10.2174/1385272823666190806114017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The use of nerve agents as warfare and in terrorist acts has drawn much attention from the governments and societies. Such toxic organophosphorus compounds are listed in Chemical Weapons Convention as Schedule 1 chemicals. The discussion about the chemical identity of the elusive Novichok agents, more potent compounds than best known G- and V-Agents, which have been implicated in recent rumorous assassination plots, clearly demonstrating the importance of the matter. Furthermore, accidents with pesticides or misuse thereof have been a pressing issue in many countries. In this context, the continued development of novel cholinesterase reactivators, antidotes for organophosphorus poisoning, a rather restricted class of pharmaceutical substances, is warranted. Testing of novel candidates may require use of actual nerve agents. Nonetheless, only a few laboratories comply with the requirements for storing, possession and manipulation of such toxic chemicals. To overcome such limitations, nerve agents’ surrogates may be a useful alternative, as they undergo the same reaction with cholinesterases, yielding similar adducts, allowing assays with novel antidote candidates, among other applications.
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Affiliation(s)
- Samir F. de A. Cavalcante
- Walter Mors Institute of Research on Natural Products (IPPN), Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Alessandro B. C. Simas
- Walter Mors Institute of Research on Natural Products (IPPN), Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Kamil Kuča
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
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30
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Cavalcante SFDA, Kitagawa DAS, Rodrigues RB, Bernardo LB, da Silva TN, Dos Santos WV, Correa ABDA, de Almeida JSFD, França TCC, Kuča K, Simas ABC. Synthesis and in vitro evaluation of neutral aryloximes as reactivators of Electrophorus eel acetylcholinesterase inhibited by NEMP, a VX surrogate. Chem Biol Interact 2019; 309:108682. [PMID: 31163137 DOI: 10.1016/j.cbi.2019.05.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/23/2019] [Accepted: 05/27/2019] [Indexed: 01/08/2023]
Abstract
Casualties caused by nerve agents, potent acetylcholinesterase inhibitors, have attracted attention from media recently. Poisoning with these chemicals may be fatal if not correctly addressed. Therefore, research on novel antidotes is clearly warranted. Pyridinium oximes are the only clinically available compounds, but poor penetration into the blood-brain barrier hampers efficient enzyme reactivation at the central nervous system. In searching for structural factors that may be explored in SAR studies, we synthesized and evaluated neutral aryloximes as reactivators for acetylcholinesterase inhibited by NEMP, a VX surrogate. Although few tested compounds reached comparable reactivation results with clinical standards, they may be considered as leads for further optimization.
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Affiliation(s)
- Samir F de A Cavalcante
- Brazilian Army Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Avenida das Américas 28705, Rio de Janeiro, 23020-470, Brazil; Walter Mors Institute of Research on Natural Products (IPPN), Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, Rio de Janeiro, 21941-902, Brazil; University Castelo Branco (UCB), School of Pharmacy, Avenida Santa Cruz 1631, Rio de Janeiro, 21710-255, Brazil; Department of Chemistry, Faculty of Science, University of Hradec Králové, Rokitanskeho 62, 50003, Hradec Králové, Czech Republic.
| | - Daniel A S Kitagawa
- Laboratory of Molecular Modelling Applied to Chemical and Biological Defense (LMACDB), Praça General Tibúrcio 80, Rio de Janeiro, 22290-270, Brazil
| | - Rafael B Rodrigues
- Brazilian Army Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Avenida das Américas 28705, Rio de Janeiro, 23020-470, Brazil
| | - Leandro B Bernardo
- Brazilian Army Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Avenida das Américas 28705, Rio de Janeiro, 23020-470, Brazil
| | - Thiago N da Silva
- University Castelo Branco (UCB), School of Pharmacy, Avenida Santa Cruz 1631, Rio de Janeiro, 21710-255, Brazil
| | - Wellington V Dos Santos
- Emergency and Rescue Department (DSE), Rio de Janeiro State Fire Department (CBMERJ), Praça São Salvador 4, Rio de Janeiro, 22231-170, Brazil; University Universus Veritas (UNIVERITAS), School of Biomedicine, Rua Marquês de Abrantes 55, Rio de Janeiro, 22230-060, Brazil
| | - Ana Beatriz de A Correa
- Brazilian Army Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN), Avenida das Américas 28705, Rio de Janeiro, 23020-470, Brazil
| | - Joyce S F D de Almeida
- Laboratory of Molecular Modelling Applied to Chemical and Biological Defense (LMACDB), Praça General Tibúrcio 80, Rio de Janeiro, 22290-270, Brazil
| | - Tanos C C França
- Department of Chemistry, Faculty of Science, University of Hradec Králové, Rokitanskeho 62, 50003, Hradec Králové, Czech Republic; Laboratory of Molecular Modelling Applied to Chemical and Biological Defense (LMACDB), Praça General Tibúrcio 80, Rio de Janeiro, 22290-270, Brazil
| | - Kamil Kuča
- Department of Chemistry, Faculty of Science, University of Hradec Králové, Rokitanskeho 62, 50003, Hradec Králové, Czech Republic
| | - Alessandro B C Simas
- Walter Mors Institute of Research on Natural Products (IPPN), Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, Rio de Janeiro, 21941-902, Brazil.
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31
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Chambers JE, Meek EC. Novel centrally active oxime reactivators of acetylcholinesterase inhibited by surrogates of sarin and VX. Neurobiol Dis 2019; 133:104487. [PMID: 31158460 DOI: 10.1016/j.nbd.2019.104487] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 05/07/2019] [Accepted: 05/30/2019] [Indexed: 11/18/2022] Open
Abstract
A novel oxime platform, the substituted phenoxyalkyl pyridinium oximes (US patent 9,227,937), was invented at Mississippi State University with an objective of discovering a brain-penetrating antidote to highly potent organophosphate anticholinesterases, such as the nerve agents. The goal was reactivation of inhibited brain acetylcholinesterase to attenuate the organophosphate-induced hypercholinergic activity that results in glutamate-mediated excitotoxicity and neuropathology. The currently approved oxime antidote in the US, 2-PAM, cannot do this. Using highly relevant surrogates of sarin and VX that leave acetylcholinesterase phosphylated with the same chemical moiety as their respective nerve agents, in vitro screens and in vivo tests in rats were conducted to identify the most efficacious members of this platform. The most promising novel oximes provided 24-h survival of lethal level surrogate exposure better than 2-PAM in almost all cases, and two of the oximes shortened the time to cessation of seizure-like behavior while 2-PAM did not. The most promising novel oximes attenuated neuropathology as indicated by immunohistochemical stains for both glia and neurons, while 2-PAM did not protect either glia or neurons. These results strongly suggest that these novel oximes can function within the brain to protect it, and therefore show great promise as potential future nerve agent antidotes.
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Affiliation(s)
- Janice E Chambers
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, United States of America.
| | - Edward C Meek
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, United States of America
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Hayes TR, Blecha JE, Thompson CM, Gerdes JM, VanBrocklin HF. Divergent synthesis of organophosphate [ 11C]VX- and [ 11C]Sarin-surrogates from a common set of starting materials. Appl Radiat Isot 2019; 151:182-186. [PMID: 31202183 DOI: 10.1016/j.apradiso.2019.05.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/09/2019] [Accepted: 05/23/2019] [Indexed: 11/27/2022]
Abstract
Radiolabeled 1-[11C]ethyl, 4-nitrophenyl methylphosphonate (VX surrogate) and 2-[11C]-propanyl, 4-nitrophenyl methylphosphonate (sarin surrogate) were developed as organophosphate (OP) tracers. The [11C]ethyl- and [11C]isopropyl-iodide radiolabeled synthons were obtained by temperature controlled, in loop reactions of [11C]CO2 with MeMgBr followed by reduction with LiAlH4, then reaction with HI. Distillation of the [11C]alkyl iodides into a solution of hydrogen (4-nitrophenyl)methylphosphonate and cesium carbonate afforded the desired tracers in >95% radiochemical purity, yields from [11C]CO2 of 1-3% and 1.7-15.1 GBq/mmol molar activities.
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Affiliation(s)
- Thomas R Hayes
- Department of Radiology and Biomedical Imaging, University of California - San Francisco, 185 Berry St. Suite 350, San Francisco, CA, 94107, United States
| | - Joseph E Blecha
- Department of Radiology and Biomedical Imaging, University of California - San Francisco, 185 Berry St. Suite 350, San Francisco, CA, 94107, United States
| | - Charles M Thompson
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, 59812, United States
| | - John M Gerdes
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, 59812, United States
| | - Henry F VanBrocklin
- Department of Radiology and Biomedical Imaging, University of California - San Francisco, 185 Berry St. Suite 350, San Francisco, CA, 94107, United States.
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Thompson CM, Gerdes JM, VanBrocklin HF. Positron emission tomography studies of organophosphate chemical threats and oxime countermeasures. Neurobiol Dis 2019; 133:104455. [PMID: 31022458 DOI: 10.1016/j.nbd.2019.04.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 03/28/2019] [Accepted: 04/19/2019] [Indexed: 01/31/2023] Open
Abstract
There is a unique in vivo interplay involving the mechanism of inactivation of acetylcholinesterase (AChE) by toxic organophosphorus (OP) compounds and the restoration of AChE activity by oxime antidotes. OP compounds form covalent adducts to this critical enzyme target and oximes are introduced to directly displace the OP from AChE. For the most part, the in vivo inactivation of AChE leading to neurotoxicity and antidote-based therapeutic reversal of this mechanism are well understood, however, these molecular-level events have not been evaluated by dynamic imaging in living systems at millimeter resolution. A deeper understanding of these critically, time-dependent mechanisms is needed to develop new countermeasures. To address this void and to help accelerate the development of new countermeasures, positron-emission tomography (PET) has been investigated as a unique opportunity to create platform technologies to directly examine the interdependent toxicokinetic/pharmacokinetic and toxicodynamic/pharmacodynamic features of OPs and oximes in real time within live animals. This review will cover two first-in-class PET tracers representing an OP and an oxime antidote, including their preparation, requisite pharmacologic investigations, mechanistic interpretations, biodistribution and imaging.
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Affiliation(s)
- Charles M Thompson
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT 59812, USA.
| | - John M Gerdes
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT 59812, USA
| | - Henry F VanBrocklin
- Department of Radiology and Biomedical Imaging, University of California, San Francisco 185 Berry St. Suite 350, San Francisco, CA 94107, USA
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Picard B, Chataigner I, Maddaluno J, Legros J. Introduction to chemical warfare agents, relevant simulants and modern neutralisation methods. Org Biomol Chem 2019; 17:6528-6537. [DOI: 10.1039/c9ob00802k] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This short review presents the current main chemical warfare agents and their most relevant simulants, and the recent catalytic and selective methods for their soft neutralization, potentially usable in the future as an alternative to “heavy” methods for decontamination.
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Touvrey C, Courageux C, Guillon V, Terreux R, Nachon F, Brazzolotto X. X-ray structures of human bile-salt activated lipase conjugated to nerve agents surrogates. Toxicology 2018; 411:15-23. [PMID: 30359675 DOI: 10.1016/j.tox.2018.10.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 10/06/2018] [Accepted: 10/20/2018] [Indexed: 01/19/2023]
Abstract
The efficiency of human butyrylcholinesterase (BChE) as a stoichiometric bioscavenger of nerve agents is well established. However, wide use is currently limited by production and purification costs. Aiming at identifying an alternative human protein bioscavenger, we looked for an original scaffold candidate by virtual screening of the Protein Data Bank for functional similarity using the "Surfing the Molecules" software (sumo-pbil.ibcp.fr) and a search model based on the BChE active site topology. Besides the expected acetylcholinesterase and butyrylcholinesterase, we identified a set of bile salt activated lipases structures, among which the human pancreatic lipase (hBAL) that shares 34% identity with BChE. We produced the recombinant enzyme in mammalian cells, purified it, and measured the inhibition constants for paraoxon and surrogates of VX, sarin and tabun. We solved the X-ray structure of apo hBAL and conjugates with paraoxon and the surrogates at resolutions in the 2-Å range. These structures allow the assessment of hBAL for scavenging nerve agents. They revealed that hBAL has inverted stereoselectivity for the surrogates of nerve agent compared to human cholinesterases. We observed a remarkable flip of the catalytic histidine driven by the chelation of Zn2+. Dealkylation of the conjugate, aka aging, was solely observed for paraoxon.
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Affiliation(s)
- Cédric Touvrey
- Institut de Biologie et Chimie des Protéines, 7 Passage du Vercors, 69367 Lyon Cedex 07, France
| | - Charlotte Courageux
- Institut de Recherche Biomédicale des Armées, Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, 91220, France
| | - Virginia Guillon
- Institut de Recherche Biomédicale des Armées, Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, 91220, France
| | - Raphael Terreux
- Institut de Biologie et Chimie des Protéines, 7 Passage du Vercors, 69367 Lyon Cedex 07, France
| | - Florian Nachon
- Institut de Recherche Biomédicale des Armées, Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, 91220, France.
| | - Xavier Brazzolotto
- Institut de Recherche Biomédicale des Armées, Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, 91220, France
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36
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Synthesis and Evaluation of Biological Activity of New Arylphosphoramidates. BIOMED RESEARCH INTERNATIONAL 2018; 2018:4567019. [PMID: 30225254 PMCID: PMC6129324 DOI: 10.1155/2018/4567019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 08/05/2018] [Indexed: 11/17/2022]
Abstract
The synthesis of new substituted arylphosphoramidates is performed in two steps through phosphorylation of the corresponding alcohols followed by aminolysis. The formation of the desired phosphoramidates depends on the subsequent addition of the two alcohols with the amine being added at the last step. The products were obtained in 58-95% yields. They were characterized mainly by multinuclear (1H, 13C, 31P, and 19F) NMR and IR spectroscopy. In addition, the antimicrobial and antiacetylcholinesterase activities were evaluated. The results showed acetylcholinesterase activity by some compounds, whilst no significant inhibitory effect against the tested bacterial strains has been recorded.
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Santoni G, de Sousa J, de la Mora E, Dias J, Jean L, Sussman JL, Silman I, Renard PY, Brown RCD, Weik M, Baati R, Nachon F. Structure-Based Optimization of Nonquaternary Reactivators of Acetylcholinesterase Inhibited by Organophosphorus Nerve Agents. J Med Chem 2018; 61:7630-7639. [DOI: 10.1021/acs.jmedchem.8b00592] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gianluca Santoni
- Université Grenoble Alpes, CEA, CNRS, IBS, F-38000 Grenoble, France
- Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France
| | - Julien de Sousa
- Université de Strasbourg, ICPEES, UMR CNRS 7515, 67087 Strasbourg, France
- Department of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
| | | | - José Dias
- Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France
| | - Ludovic Jean
- Université de Normandie, COBRA, UMR 6014, FR 3038, Université de Rouen, INSA de Rouen, CNRS, 76821 Mont-Saint-Aignan, France
| | - Joel L. Sussman
- Department of Structural Biology, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Israel Silman
- Department of Neurobiology, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Pierre-Yves Renard
- Université de Normandie, COBRA, UMR 6014, FR 3038, Université de Rouen, INSA de Rouen, CNRS, 76821 Mont-Saint-Aignan, France
| | - Richard C. D. Brown
- Department of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
| | - Martin Weik
- Université Grenoble Alpes, CEA, CNRS, IBS, F-38000 Grenoble, France
| | - Rachid Baati
- Université de Strasbourg, ICPEES, UMR CNRS 7515, 67087 Strasbourg, France
| | - Florian Nachon
- Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France
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Chao CK, Balasubramanian N, Gerdes JM, Thompson CM. The inhibition, reactivation and mechanism of VX-, sarin-, fluoro-VX and fluoro-sarin surrogates following their interaction with HuAChE and HuBuChE. Chem Biol Interact 2018; 291:220-227. [PMID: 29920286 PMCID: PMC6061941 DOI: 10.1016/j.cbi.2018.06.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/20/2018] [Accepted: 06/15/2018] [Indexed: 10/14/2022]
Abstract
In this study, the mechanisms of HuAChE and HuBChE inhibition by Me-P(O) (OPNP) (OR) [PNP = p-nitrophenyl; R = CH2CH3, CH2CH2F, OCH(CH3)2, OCH(CH3) (CH2F)] representing surrogates and fluoro-surrogates of VX and sarin were studied by in vitro kinetics and mass spectrometry. The in vitro measures showed that the VX- and fluoro-VX surrogates were relatively strong inhibitors of HuAChE and HuBChE (ki ∼ 105-106 M-1min-1) and underwent spontaneous and 2-PAM-mediated reactivation within 30 min. The sarin surrogates were weaker inhibitors of HuAChE and HuBChE (ki ∼ 104-105 M-1min-1), and in general did not undergo spontaneous reactivation, although HuAChE adducts were partially reactivatable at 18 h using 2-PAM. The mechanism of HuAChE and HuBChE inhibition by the surrogates was determined by Q-TOF and MALDI-TOF mass spectral analyses. The surrogate-adducted proteins were trypsin digested and the active site-containing peptide bearing the OP-modified serine identified by Q-TOF as triply- and quadruply-charged ions representing the respective increase in mass of the attached OP moiety. Correspondingly, monoisotopic ions of the tryptic peptides representing the mass increase of the OP-adducted peptide was identified by MALDI-TOF. The mass spectrometry analyses validated the identity of the OP moiety attached to HuAChE or HuBChE as MeP(O) (OR)-O-serine peptides (loss of the PNP leaving group) via mechanisms consistent with those found with chemical warfare agents. MALDI-TOF MS analyses of the VX-modified peptides versus time showed a steady reduction in adduct versus parent peptide (reactivation), whereas the sarin-surrogate-modified peptides remained largely intact over the course of the experiment (24 h). Overall, the presence of a fluorine atom on the surrogate modestly altered the rate constants of inhibition and reactivation, however, the mechanism of inhibition (ejection of PNP group) did not change.
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Affiliation(s)
- Chih-Kai Chao
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, 59812, United States
| | | | - John M Gerdes
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, 59812, United States
| | - Charles M Thompson
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, 59812, United States.
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Dail MB, Meek EC, Chambers HW, Chambers JE. In vitro P-glycoprotein activity does not completely explain in vivo efficacy of novel centrally effective oxime acetylcholinesterase reactivators. Drug Chem Toxicol 2018; 42:403-408. [PMID: 29722548 DOI: 10.1080/01480545.2018.1461902] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Novel-substituted phenoxyalkyl pyridinium oxime acetylcholinesterase (AChE) reactivators (US patent 9,227,937) that showed convincing evidence of penetration into the brains of intact rats were developed by our laboratories. The oximes separated into three groups based on their levels of brain AChE reactivation following exposure of rats to the sarin surrogate nitrophenyl isopropyl methylphosphonate (NIMP). P-glycoprotein (P-gp) is a major blood-brain barrier (BBB) transporter and requires ATP for efflux. To determine if P-gp affinity screening could be used to reduce animal use, we measured in vitro oxime-stimulated ATPase activity to see if the in vivo reactivation efficacies related to the oximes' functions as P-gp substrates. High efficacy oximes were expected to be poor P-gp substrates, thus remaining in the brain longer. The high efficacy oximes (24-35% brain AChE reactivation) were worse P-gp substrates than the low efficacy oximes (0-7% brain AChE reactivation). However, the oxime group with medium in vivo reactivation of 10-17% were even worse P-gp substrates than the high efficacy group so their reactivation ability was not reflected by P-gp export. The results suggest that in vitro P-gp ATPase activity can remove the low efficacy oximes from in vivo testing, but is not sufficient to differentiate between the top two tiers.
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Affiliation(s)
- Mary Beth Dail
- a Center for Environmental Health Sciences, Department of Basic Sciences , College of Veterinary Medicine, Mississippi State University, Mississippi State , MS , USA
| | - Edward Caldwell Meek
- a Center for Environmental Health Sciences, Department of Basic Sciences , College of Veterinary Medicine, Mississippi State University, Mississippi State , MS , USA
| | - Howard Wayne Chambers
- b Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology , Entomology Unit, Mississippi State University, Mississippi State , MS , USA
| | - Janice Elaine Chambers
- a Center for Environmental Health Sciences, Department of Basic Sciences , College of Veterinary Medicine, Mississippi State University, Mississippi State , MS , USA
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40
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Cavalcante SFA, de Paula RL, Kitagawa DAS, Barcellos MC, Simas ABC, Granjeiro JM. Synthesis of reference compounds related to Chemical Weapons Convention for verification and drug development purposes – a Brazilian endeavour. ACTA ACUST UNITED AC 2018. [DOI: 10.1088/1742-6596/975/1/012020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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41
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Neumann KD, Thompson CM, Blecha JE, Gerdes JM, VanBrocklin HF. An improved radiosynthesis of O-(2-[ 18 F]fluoroethyl)-O-(p-nitrophenyl)methylphosphonate: A first-in-class cholinesterase PET tracer. J Labelled Comp Radiopharm 2017; 60:337-342. [PMID: 28406525 DOI: 10.1002/jlcr.3511] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 03/31/2017] [Accepted: 04/05/2017] [Indexed: 11/06/2022]
Abstract
O-(2-Fluoroethyl)-O-(p-nitrophenyl) methylphosphonate 1 is an organophosphate cholinesterase inhibitor that creates a phosphonyl-serine covalent adduct at the enzyme active site blocking cholinesterase activity in vivo. The corresponding radiolabeled O-(2-[18 F]fluoroethyl)-O-(p-nitrophenyl) methylphosphonate, [18 F]1, has been previously prepared and found to be an excellent positron emission tomography imaging tracer for assessment of cholinesterases in live brain, peripheral tissues, and blood. However, the previously reported [18 F]1 tracer synthesis was slow even with microwave acceleration, required high-performance liquid chromatography separation of the tracer from impurities, and gave less optimal radiochemical yields. In this paper, we report a new synthetic approach to circumvent these shortcomings that is reliant on the facile reactivity of bis-(O,O-p-nitrophenyl) methylphosphonate, 2, with 2-fluoroethanol in the presence of DBU. The cold synthesis was successfully translated to provide a more robust radiosynthesis. Using this new strategy, the desired tracer, [18 F]1, was obtained in a non-decay-corrected radiochemical yield of 8 ± 2% (n = 7) in >99% radiochemical and >95% chemical purity with a specific activity of 3174 ± 345 Ci/mmol (EOS). This new facile radiosynthesis routinely affords highly pure quantities of [18 F]1, which will further enable tracer development of OP cholinesterase inhibitors and their evaluation in vivo.
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Affiliation(s)
- Kiel D Neumann
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - Charles M Thompson
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, USA
| | - Joseph E Blecha
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - John M Gerdes
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, USA
| | - Henry F VanBrocklin
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
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42
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Chao CK, Ahmed SK, Gerdes JM, Thompson CM. Novel Organophosphate Ligand O-(2-Fluoroethyl)-O-(p-Nitrophenyl)Methylphosphonate: Synthesis, Hydrolytic Stability and Analysis of the Inhibition and Reactivation of Cholinesterases. Chem Res Toxicol 2016; 29:1810-1817. [PMID: 27551891 PMCID: PMC5575788 DOI: 10.1021/acs.chemrestox.6b00160] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The organophosphate O-(2-fluoroethyl)-O-(p-nitrophenyl) methyphosphonate 1 is the first-in-class, fluorine-18 radiolabeled organophosphate inhibitor ([18F]1) of acetylcholinesterase (AChE). In rats, [18F]1 localizes in AChE rich regions of the brain and other tissues where it likely exists as the (CH3)(18FCH2CH2O)P(O)-AChE adduct (ChE-1). Characterization of this adduct would define the inhibition mechanism and subsequent postinhibitory pathways and reactivation rates. To validate this adduct, the stability (hydrolysis) of 1 and ChE-1 reactivation rates were determined. Base hydrolysis of 1 yields p-nitrophenol and (CH3) (FCH2CH2O)P(O)OH with pseudo first order rate constants (kobsd) at pH 7.4 (PBS) of 3.25 × 10-4 min-1 (t1/2 = 35.5 h) at 25 °C and 8.70 × 10-4 min-1 (t1/2 = 13.3 h) at 37 °C. Compound 1 was a potent inhibitor of human acetylcholinesterase (HuAChE; ki = 7.5 × 105 M-1 min-1), electric eel acetylcholinesterase (EEAChE) (ki = 3.0 × 106 M-1 min-1), and human serum butyrylcholinesterase (HuBChE; 1.95 × 105 M-1 min-1). Spontaneous and oxime-mediated reactivation rates for the (CH3) (FCH2CH2O)P(O)-serine ChE adducts using 2-PAM (10 μM) were (a) HuAChE 8.8 × 10-5 min-1 (t1/2 = 131.2 h) and 2.41 × 10-2 min-1 (t1/2 = 0.48 h), (b) EEAChE 9.32 × 10-3 min-1 (t1/2 = 1.24 h) and 3.33 × 10-2 min-1 (t1/2 = 0.35 h), and (c) HuBChE 1.16 × 10-4 min-1 (t1/2 = 99.6 h) and 4.19 × 10-2 min-1 (t1/2 = 0.27 h). All ChE-1 adducts undergo rapid and near complete restoration of enzyme activity following addition of 2-PAM (30 min), and no aging was observed for either reactivation process. The fast reactivation rates and absence of aging of ChE-1 adducts are explained on the basis of the electron-withdrawing fluorine group that favors the nucleophilic reactivation processes but disfavors cation-based dealkylation aging mechanisms. Therefore, the likely fate of radiolabeled compound 1 in vivo is the formation of (CH3)(FCH2CH2O)P(O)-serine adducts and monoacid (CH3)(FCH2CH2O)P(O)OH from hydrolysis and reactivation.
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Affiliation(s)
- Chih-Kai Chao
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana 59812, United States
| | - S. Kaleem Ahmed
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana 59812, United States
- Center for Neuromolecular Research, Drug Discovery Division, Southern Research Institute, Birmingham, Alabama 35205, United States
| | - John M. Gerdes
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana 59812, United States
- Center for Neuromolecular Research, Drug Discovery Division, Southern Research Institute, Birmingham, Alabama 35205, United States
| | - Charles M. Thompson
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana 59812, United States
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Efficacy of novel phenoxyalkyl pyridinium oximes as brain-penetrating reactivators of cholinesterase inhibited by surrogates of sarin and VX. Chem Biol Interact 2016; 259:154-159. [DOI: 10.1016/j.cbi.2016.07.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 04/22/2016] [Accepted: 07/03/2016] [Indexed: 11/20/2022]
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Gorecki L, Korabecny J, Musilek K, Malinak D, Nepovimova E, Dolezal R, Jun D, Soukup O, Kuca K. SAR study to find optimal cholinesterase reactivator against organophosphorous nerve agents and pesticides. Arch Toxicol 2016; 90:2831-2859. [PMID: 27582056 DOI: 10.1007/s00204-016-1827-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 08/22/2016] [Indexed: 01/13/2023]
Abstract
Irreversible inhibition of acetylcholinesterase (AChE) by organophosphates leads to many failures in living organism and ultimately in death. Organophosphorus compounds developed as nerve agents such as tabun, sarin, soman, VX and others belong to the most toxic chemical warfare agents and are one of the biggest threats to the modern civilization. Moreover, misuse of nerve agents together with organophosphorus pesticides (e.g. malathion, paraoxon, chlorpyrifos, etc.) which are annually implicated in millions of intoxications and hundreds of thousand deaths reminds us of insufficient protection against these compounds. Basic treatments for these intoxications are based on immediate administration of atropine and acetylcholinesterase reactivators which are currently represented by mono- or bis-pyridinium aldoximes. However, these antidotes are not sufficient to ensure 100 % treatment efficacy even they are administered immediately after intoxication, and in general, they possess several drawbacks. Herein, we have reviewed new efforts leading to the development of novel reactivators and proposition of new promising strategies to design novel and effective antidotes. Structure-activity relationships and biological activities of recently proposed acetylcholinesterase reactivators are discussed and summarized. Among further modifications of known oximes, the main attention has been paid to dual binding site ligands of AChE as the current mainstream strategy. We have also discussed new chemical entities as potential replacement of oxime functional group.
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Affiliation(s)
- Lukas Gorecki
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Jan Korabecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Kamil Musilek
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic.,Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
| | - David Malinak
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Physiology and Pathophysiology, Faculty of Medicine, University of Ostrava, Syllabova 19, 703 00, Ostrava, Czech Republic
| | - Eugenie Nepovimova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Rafael Dolezal
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic
| | - Daniel Jun
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Ondrej Soukup
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05, Hradec Kralove, Czech Republic. .,Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03, Hradec Kralove, Czech Republic.
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Chambers JE, Meek EC, Chambers HW. Novel brain-penetrating oximes for reactivation of cholinesterase inhibited by sarin and VX surrogates. Ann N Y Acad Sci 2016; 1374:52-8. [PMID: 27153507 DOI: 10.1111/nyas.13053] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Current oxime reactivators for organophosphate-inhibited cholinesterase (ChE) do not effectively cross the blood-brain barrier and therefore cannot restore brain ChE activity in vivo. Our laboratories have studied highly relevant sarin and VX surrogates, which differ from their respective nerve agents only in the leaving group and thereby leave ChE phosphylated with the same chemical moiety as sarin and VX. Our laboratories have developed novel substituted phenoxyalkyl pyridinium oximes that lead to reduced ChE inhibition in the brains of rats challenged with a high sublethal dosage of the sarin surrogate, whereas 2-PAM did not, using a paradigm designed to demonstrate brain penetration. In addition, treatment of rats with these novel oximes is associated with attenuation of seizure-like behavior compared to rats treated with 2-PAM, providing additional evidence that the oximes penetrate the blood-brain barrier. Further, some of the oximes provided 24-h survival superior to 2-PAM, and shortened the duration of seizure-like behavior when rats were challenged with lethal dosages of the sarin and VX surrogates, providing additional support for the conclusion that these oximes penetrate the brain.
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Affiliation(s)
- Janice E Chambers
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi
| | - Edward C Meek
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi
| | - Howard W Chambers
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, Mississippi
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46
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Comparison of inhibition kinetics of several organophosphates, including some nerve agent surrogates, using human erythrocyte and rat and mouse brain acetylcholinesterase. Toxicol Lett 2016; 248:39-45. [PMID: 26965078 DOI: 10.1016/j.toxlet.2016.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 02/19/2016] [Accepted: 03/02/2016] [Indexed: 11/24/2022]
Abstract
Because testing of nerve agents is limited to only authorized facilities, our laboratory developed several surrogates that resemble nerve agents because they phosphylate the acetylcholinesterase (AChE) with the same moiety as the actual nerve agents. The inhibition kinetic parameters were determined for AChE by surrogates of cyclosarin (NCMP), sarin (NIMP, PIMP and TIMP) and VX (NEMP and TEMP) and other organophosphorus compounds derived from insecticides. All compounds were tested with rat brain and a subset was tested with mouse brain and purified human erythrocyte AChE. Within the compounds tested on all AChE sources, chlorpyrifos-oxon had the highest molecular rate constant followed by NCMP and NEMP. This was followed by NIMP then paraoxon and DFP with rat and mouse brain AChE but DFP was a more potent inhibitor than NIMP and paraoxon with human AChE. With the additional compounds tested only in rat brain, TEMP was slightly less potent than NEMP but more potent than PIMP which was more potent than NIMP. Methyl paraoxon was slightly less potent than paraoxon but more potent than TIMP which was more potent than DFP. Overall, this study validates that the pattern of inhibitory potencies of our surrogates is comparable to the pattern of inhibitory potencies of actual nerve agents (i.e., cyclosarin>VX>sarin), and that these are more potent than insecticidal organophosphates.
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47
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Chambers JE, Meek EC, Bennett JP, Bennett WS, Chambers HW, Leach CA, Pringle RB, Wills RW. Novel substituted phenoxyalkyl pyridinium oximes enhance survival and attenuate seizure-like behavior of rats receiving lethal levels of nerve agent surrogates. Toxicology 2015; 339:51-57. [PMID: 26705700 DOI: 10.1016/j.tox.2015.12.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 12/03/2015] [Accepted: 12/11/2015] [Indexed: 11/16/2022]
Abstract
Novel substituted phenoxyalkyl pyridinium oximes, previously shown to reactivate brain cholinesterase in rats treated with high sublethal dosages of surrogates of sarin and VX, were tested for their ability to prevent mortality from lethal doses of these two surrogates. Rats were treated subcutaneously with 0.6mg/kg nitrophenyl isopropyl methylphosphonate (NIMP; sarin surrogate) or 0.65mg/kg nitrophenyl ethyl methylphosphonate (NEMP; VX surrogate), dosages that were lethal within 24h to all tested rats when they received only 0.65mg/kg atropine at the time of initiation of seizure-like behavior (about 30min). If 146mmol/kg 2-PAM (human equivalent dosage) was also administered, 40% and 33% survival was obtained with NIMP and NEMP, respectively, while the novel Oximes 1 and 20 provided 65% and 55% survival for NIMP and 75 and 65% for NEMP, respectively. In addition, both novel oximes resulted in a highly significant decrease in time to cessation of seizure-like behavior compared to 2-PAM during the first 8h of observation. Brain cholinesterase inhibition was slightly less in novel oxime treated rats compared to 2-PAM in the 24h survivors. The lethality data indicate that 24h survival is improved by two of the novel oximes compared to 2-PAM. The cessation of seizure-like behavior data strongly suggest that these novel oximes are able to penetrate the blood-brain barrier and can combat the hypercholinergic activity that results in seizures. Therefore this oxime platform has exceptional promise as therapy that could both prevent nerve agent-induced lethality and attenuate nerve agent-induced seizures.
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Affiliation(s)
- Janice E Chambers
- Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, P.O. Box 6100, Mississippi State, MS 39762, USA.
| | - Edward C Meek
- Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, P.O. Box 6100, Mississippi State, MS 39762, USA.
| | - Joshua P Bennett
- Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, P.O. Box 6100, Mississippi State, MS 39762, USA.
| | - W Shane Bennett
- Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, P.O. Box 6100, Mississippi State, MS 39762, USA.
| | - Howard W Chambers
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, P.O. Box 9775, Mississippi State, MS 39762, USA.
| | - C Andrew Leach
- Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, P.O. Box 6100, Mississippi State, MS 39762, USA.
| | - Ronald B Pringle
- Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, P.O. Box 6100, Mississippi State, MS 39762, USA.
| | - Robert W Wills
- Department of Pathobiology/Population Medicine, College of Veterinary Medicine, Mississippi State University, P.O. Box 6100, Mississippi State, MS 39762, USA.
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48
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Meek EC, Chambers HW, Pringle RB, Chambers JE. The effect of PON1 enhancers on reducing acetylcholinesterase inhibition following organophosphate anticholinesterase exposure in rats. Toxicology 2015; 336:79-83. [DOI: 10.1016/j.tox.2015.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 08/06/2015] [Accepted: 08/09/2015] [Indexed: 11/28/2022]
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49
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Katz FS, Pecic S, Tran TH, Trakht I, Schneider L, Zhu Z, Ton-That L, Luzac M, Zlatanic V, Damera S, Macdonald J, Landry DW, Tong L, Stojanovic MN. Discovery of New Classes of Compounds that Reactivate Acetylcholinesterase Inhibited by Organophosphates. Chembiochem 2015; 16:2205-2215. [PMID: 26350723 DOI: 10.1002/cbic.201500348] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Indexed: 11/11/2022]
Abstract
Acetylcholinesterase (AChE) that has been covalently inhibited by organophosphate compounds (OPCs), such as nerve agents and pesticides, has traditionally been reactivated by using nucleophilic oximes. There is, however, a clearly recognized need for new classes of compounds with the ability to reactivate inhibited AChE with improved in vivo efficacy. Here we describe our discovery of new functional groups--Mannich phenols and general bases--that are capable of reactivating OPC--inhibited AChE more efficiently than standard oximes and we describe the cooperative mechanism by which these functionalities are delivered to the active site. These discoveries, supported by preliminary in vivo results and crystallographic data, significantly broaden the available approaches for reactivation of AChE.
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Affiliation(s)
- Francine S Katz
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Stevan Pecic
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Timothy H Tran
- Department of Biological Sciences, Columbia University, 1212 Amsterdam Avenue, New York, NY 10027 (USA)
| | - Ilya Trakht
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Laura Schneider
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Zhengxiang Zhu
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Long Ton-That
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Michal Luzac
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Viktor Zlatanic
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Shivani Damera
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Joanne Macdonald
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA).,Genecology Research Centre, Inflammation and Healing Research Cluster, School of Science and Engineering, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD 4556 (Australia)
| | - Donald W Landry
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Liang Tong
- Department of Biological Sciences, Columbia University, 1212 Amsterdam Avenue, New York, NY 10027 (USA)
| | - Milan N Stojanovic
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA).,Departments of Biomedical Engineering and Systems Biology, Columbia University, 630 W. 168th street, New York, NY 10032 (USA)
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50
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Chambers JE, Chambers HW, Meek EC, Funck KE, Bhavaraju MH, Gwaltney SR, Pringle RB. Novel Nucleophiles Enhance the Human Serum Paraoxonase 1 (PON1)-mediated Detoxication of Organophosphates. Toxicol Sci 2014; 143:46-53. [DOI: 10.1093/toxsci/kfu205] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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