1
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Neurotoxicity evoked by organophosphates and available countermeasures. Arch Toxicol 2023; 97:39-72. [PMID: 36335468 DOI: 10.1007/s00204-022-03397-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/11/2022] [Indexed: 11/07/2022]
Abstract
Organophosphorus compounds (OP) are a constant problem, both in the military and in the civilian field, not only in the form of acute poisoning but also for their long-lasting consequences. No antidote has been found that satisfactorily protects against the toxic effects of organophosphates. Likewise, there is no universal cure to avert damage after poisoning. The key mechanism of organophosphate toxicity is the inhibition of acetylcholinesterase. The overstimulation of nicotinic or muscarinic receptors by accumulated acetylcholine on a synaptic cleft leads to activation of the glutamatergic system and the development of seizures. Further consequences include generation of reactive oxygen species (ROS), neuroinflammation, and the formation of various other neuropathologists. In this review, we present neuroprotection strategies which can slow down the secondary nerve cell damage and alleviate neurological and neuropsychiatric disturbance. In our opinion, there is no unequivocal approach to ensure neuroprotection, however, sooner the neurotoxicity pathway is targeted, the better the results which can be expected. It seems crucial to target the key propagation pathways, i.e., to block cholinergic and, foremostly, glutamatergic cascades. Currently, the privileged approach oriented to stimulating GABAAR by benzodiazepines is of limited efficacy, so that antagonizing the hyperactivity of the glutamatergic system could provide an even more efficacious approach for terminating OP-induced seizures and protecting the brain from permanent damage. Encouraging results have been reported for tezampanel, an antagonist of GluK1 kainate and AMPA receptors, especially in combination with caramiphen, an anticholinergic and anti-glutamatergic agent. On the other hand, targeting ROS by antioxidants cannot or already developed neuroinflammation does not seem to be very productive as other processes are also involved.
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2
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Kumaran A, Vashishth R, Singh S, U S, James A, Velayudhaperumal Chellam P. Biosensors for detection of organophosphate pesticides: Current technologies and future directives. Microchem J 2022. [DOI: 10.1016/j.microc.2022.107420] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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3
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Daley SK, Cordell GA. Biologically Significant and Recently Isolated Alkaloids from Endophytic Fungi. JOURNAL OF NATURAL PRODUCTS 2021; 84:871-897. [PMID: 33534564 DOI: 10.1021/acs.jnatprod.0c01195] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A selection of the established and recently characterized alkaloids from the exploration of plant- and some marine-associated endophytic fungi is reviewed, with reference to alkaloids of biological significance.
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Affiliation(s)
| | - Geoffrey A Cordell
- Natural Products Inc., Evanston, Illinois 60202, United States
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
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4
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Lenina OA, Zueva IV, Zobov VV, Semenov VE, Masson P, Petrov KA. Slow-binding reversible inhibitor of acetylcholinesterase with long-lasting action for prophylaxis of organophosphate poisoning. Sci Rep 2020; 10:16611. [PMID: 33024231 PMCID: PMC7538863 DOI: 10.1038/s41598-020-73822-6] [Citation(s) in RCA: 9] [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: 07/29/2020] [Accepted: 09/22/2020] [Indexed: 12/02/2022] Open
Abstract
Organophosphorus (OP) compounds represent a serious health hazard worldwide. The dominant mechanism of their action results from covalent inhibition of acetylcholinesterase (AChE). Standard therapy of acute OP poisoning is partially effective. However, prophylactic administration of reversible or pseudo-irreversible AChE inhibitors before OP exposure increases the efficiency of standard therapy. The purpose of the study was to test the duration of the protective effect of a slow-binding reversible AChE inhibitor (C547) in a mouse model against acute exposure to paraoxon (POX). It was shown that the rate of inhibition of AChE by POX in vitro after pre-inhibition with C547 was several times lower than without C547. Ex vivo pre-incubation of mouse diaphragm with C547 significantly prevented the POX-induced muscle weakness. Then it was shown that pre-treatment of mice with C547 at the dose of 0.01 mg/kg significantly increased survival after poisoning by 2xLD50 POX. The duration of the pre-treatment was effective up to 96 h, whereas currently used drug for pre-exposure treatment, pyridostigmine at a dose of 0.15 mg/kg was effective less than 24 h. Thus, long-lasting slow-binding reversible AChE inhibitors can be considered as new potential drugs to increase the duration of pre-exposure treatment of OP poisoning.
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Affiliation(s)
- Oksana A Lenina
- Arbuzov Institute of Organic and Physical Chemistry, Federal Research Center "Kazan Scientific Center of the Russian Academy of Sciences", Arbuzov str., 8, Kazan, Russian Federation, 420088
| | - Irina V Zueva
- Arbuzov Institute of Organic and Physical Chemistry, Federal Research Center "Kazan Scientific Center of the Russian Academy of Sciences", Arbuzov str., 8, Kazan, Russian Federation, 420088
| | - Vladimir V Zobov
- Arbuzov Institute of Organic and Physical Chemistry, Federal Research Center "Kazan Scientific Center of the Russian Academy of Sciences", Arbuzov str., 8, Kazan, Russian Federation, 420088
- Kazan Federal University, 18 Kremlyovskaya str, Kazan, Russia, 420008
| | - Vyacheslav E Semenov
- Arbuzov Institute of Organic and Physical Chemistry, Federal Research Center "Kazan Scientific Center of the Russian Academy of Sciences", Arbuzov str., 8, Kazan, Russian Federation, 420088
| | - Patrick Masson
- Kazan Federal University, 18 Kremlyovskaya str, Kazan, Russia, 420008
| | - Konstantin A Petrov
- Arbuzov Institute of Organic and Physical Chemistry, Federal Research Center "Kazan Scientific Center of the Russian Academy of Sciences", Arbuzov str., 8, Kazan, Russian Federation, 420088.
- Kazan Federal University, 18 Kremlyovskaya str, Kazan, Russia, 420008.
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5
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Efficacy Assessment of an Uncharged Reactivator of NOP-Inhibited Acetylcholinesterase Based on Tetrahydroacridine Pyridine-Aldoxime Hybrid in Mouse Compared to Pralidoxime. Biomolecules 2020; 10:biom10060858. [PMID: 32512884 PMCID: PMC7355633 DOI: 10.3390/biom10060858] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/01/2020] [Accepted: 06/03/2020] [Indexed: 12/11/2022] Open
Abstract
(1) Background: Human exposure to organophosphorus compounds employed as pesticides or as chemical warfare agents induces deleterious effects due to cholinesterase inhibition. One therapeutic approach is the reactivation of inhibited acetylcholinesterase by oximes. While currently available oximes are unable to reach the central nervous system to reactivate cholinesterases or to display a wide spectrum of action against the variety of organophosphorus compounds, we aim to identify new reactivators without such drawbacks. (2) Methods: This study gathers an exhaustive work to assess in vitro and in vivo efficacy, and toxicity of a hybrid tetrahydroacridine pyridinaldoxime reactivator, KM297, compared to pralidoxime. (3) Results: Blood–brain barrier crossing assay carried out on a human in vitro model established that KM297 has an endothelial permeability coefficient twice that of pralidoxime. It also presents higher cytotoxicity, particularly on bone marrow-derived cells. Its strong cholinesterase inhibition potency seems to be correlated to its low protective efficacy in mice exposed to paraoxon. Ventilatory monitoring of KM297-treated mice by double-chamber plethysmography shows toxic effects at the selected therapeutic dose. This breathing assessment could help define the No Observed Adverse Effect Level (NOAEL) dose of new oximes which would have a maximum therapeutic effect without any toxic side effects.
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6
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Zhang HB, Hu J, Li JX, Hao SH. Cytotoxic lycodine alkaloids from the aerial parts of Lycopodiastrum casuarinoides. JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH 2020; 22:217-224. [PMID: 30740993 DOI: 10.1080/10286020.2018.1552681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 11/22/2018] [Indexed: 06/09/2023]
Abstract
A phytochemical investigation on the 75% EtOH extract of the aerial parts of Lycopodiastrum casuarinoides resulted in the isolation of three new lycodine alkaloids, 16-hydroxy-9-oxo-lycocasuarinine D (1), 6α-hydroxy-16-dehydroxy-lycocasuarinine A (2), and 6α,16-dihydroxy-lycocasuarinine B (3). Structural elucidation of all the compounds was performed by spectral methods such as 1D- and 2D-NMR, infrared, ultraviolet, and HR-ESI-MS. The isolated alkaloids were tested in vitro for cytotoxic potential against six lung cancer cell lines. Consequently, alkaloid 1 exhibited cytotoxicity against all the tested tumor cell lines with IC50 values less than 20 μM.[Formula: see text].
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Affiliation(s)
- Hai-Bo Zhang
- Department of Radiation Oncology, The General Hospital of Shenyang Military Area Command, Shenyang 110016, China
| | - Jiang Hu
- College of Biological Resources and Food Engineering, Qujing Normal University, Qujing 655011, China
| | - Jia-Xun Li
- Tumor Hospital of Yunnan Province, The Third Affiliated Hospital of Kunming Medical University, Kunming 650118, China
| | - Shan-Hu Hao
- Department of Nuclear Medicine, The General Hospital of Shenyang Military Area Command, Shenyang 110016, China
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7
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Davletshina R, Ivanov A, Evtugyn G. Acetylcholinesterase Sensor Based on Polyelectrolyte Complexes with DNA Inclusion for the Determination of Reversible Inhibitors. ELECTROANAL 2019. [DOI: 10.1002/elan.201900507] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- R. Davletshina
- A. M. Butlerov' Chemistry Institute of Kazan Federal University 18 Kremlevskaya street Kazan 420008 Russian Federation
| | - A. Ivanov
- A. M. Butlerov' Chemistry Institute of Kazan Federal University 18 Kremlevskaya street Kazan 420008 Russian Federation
| | - G. Evtugyn
- A. M. Butlerov' Chemistry Institute of Kazan Federal University 18 Kremlevskaya street Kazan 420008 Russian Federation
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8
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Bajgar J, Kassa J, Kucera T, Musilek K, Jun D, Kuca K. Some Possibilities to Study New Prophylactics against Nerve Agents. Mini Rev Med Chem 2019; 19:970-979. [PMID: 30827238 DOI: 10.2174/1389557519666190301112530] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 04/10/2017] [Accepted: 04/26/2017] [Indexed: 11/22/2022]
Abstract
Nerve agents belong to the most dangerous chemical warfare agents and can be/were misused by terrorists. Effective prophylaxis and treatment is necessary to diminish their effect. General principles of prophylaxis are summarized (protection against acetylcholinesterase inhibition, detoxification, treatment "in advance" and use of different drugs). They are based on the knowledge of mechanism of action of nerve agents. Among different examinations, it is necessary to test prophylactic effectivity in vivo and compare the results with protection in vitro. Chemical and biological approaches to the development of new prophylactics would be applied simultaneously during this research. Though the number of possible prophylactics is relatively high, the only four drugs were introduced into military medical practice. At present, pyridostigmine seems to be common prophylactic antidote; prophylactics panpal (tablets with pyridostigmine, trihexyphenidyl and benactyzine), transant (transdermal patch containing HI-6) are other means introduced into different armies as prophylactics. Scavenger commercionally available is Protexia®. Future development will be focused on scavengers, and on other drugs either reversible cholinesterase inhibitors (e.g., huperzine A, gallantamine, physostigmine, acridine derivatives) or other compounds.
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Affiliation(s)
- J Bajgar
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - J Kassa
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - T Kucera
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - K Musilek
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
| | - D Jun
- Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - K Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
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9
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Lorke DE, Nurulain SM, Hasan MY, Kuča K, Petroianu GA. Oximes as pretreatment before acute exposure to paraoxon. J Appl Toxicol 2019; 39:1506-1515. [PMID: 31264735 DOI: 10.1002/jat.3835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 05/15/2019] [Accepted: 05/16/2019] [Indexed: 11/11/2022]
Abstract
Organophosphates, useful agents as pesticides, also represent a serious danger due to their high acute toxicity. There is indication that oximes, when administered before organophosphate exposure, can protect from these toxic effects. We have tested at equitoxic dosage (25% of LD01 ) the prophylactic efficacy of five experimental (K-48, K-53, K-74, K-75, K-203) and two established oximes (pralidoxime and obidoxime) to protect from mortality induced by the organophosphate paraoxon. Mortalities were quantified by Cox analysis and compared with those observed after pretreatment with a strong acetylcholinesterase inhibitor (10-methylacridine) and after the FDA-approved pretreatment compound pyridostigmine. All nine tested substances statistically significantly reduced paraoxon-induced mortality. Best protection was conferred by the experimental oxime K-48, reducing the relative risk of death (RR) to 0.10, which was statistically significantly superior to pyridostigmine (RR = 0.31). The other oximes reduced the RR to 0.13 (obidoxime), 0.20 (K-203), 0.21 (K-74), 0.24 (K-75) and 0.26 (pralidoxime), which were significantly more efficacious than 10-methylacridine (RR = 0.65). These data support the hypothesis that protective efficacy is not primarily due to cholinesterase inhibition and indicate that the tested experimental oximes may be considered promising alternatives to the established pretreatment compound pyridostigmine.
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Affiliation(s)
- Dietrich E Lorke
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, University Park GL 495 D, Florida International University, Miami, Florida.,College of Medicine and Health Sciences, Department of Anatomy and Cellular Biology, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Syed M Nurulain
- Department of Bio Science, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Mohamed Y Hasan
- Department of Pharmacology & Therapeutics, College of Medicine and Health Sciences, UAE University, United Arab Emirates
| | - Kamil Kuča
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Georg A Petroianu
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, University Park GL 495 D, Florida International University, Miami, Florida
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10
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Vitorović-Todorović MD, Worek F, Perdih A, Bauk SĐ, Vujatović TB, Cvijetić IN. The in vitro protective effects of the three novel nanomolar reversible inhibitors of human cholinesterases against irreversible inhibition by organophosphorous chemical warfare agents. Chem Biol Interact 2019; 309:108714. [PMID: 31228470 DOI: 10.1016/j.cbi.2019.06.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 06/10/2019] [Accepted: 06/13/2019] [Indexed: 10/26/2022]
Abstract
Acetylcholinesterase (AChE) is an enzyme which terminates the cholinergic neurotransmission, by hydrolyzing acetylcholine at the nerve and nerve-muscle junctions. The reversible inhibition of AChE was suggested as the pre-treatment option of the intoxications caused by nerve agents. Based on our derived 3D-QSAR model for the reversible AChE inhibitors, we designed and synthesized three novel compounds 8-10, joining the tacrine and aroylacrylic acid phenylamide moieties, with a longer methylene chain to target two distinct, toplogically separated anionic areas on the AChE. The targeted compounds exerted low nanomolar to subnanomolar potency toward the E. eel and human AChE's as well as the human BChE and showed mixed inhibition type in kinetic studies. All compounds were able to slow down the irreversible inhibition of the human AChE by several nerve agents including tabun, soman and VX, with the estimated protective indices around 5, indicating a valuable level of protection. Putative noncovalent interactions of the selected ligand 10 with AChE active site gorge were finally explored by molecular dynamics simulation suggesting a formation of the salt bridge between the protonated linker amino group and the negatively charged Asp74 carboxylate side chain as a significant player for the successful molecular recognition in line with the design strategy. The designed compounds may represent a new class of promising leads for the development of more effective pre-treatment options.
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Affiliation(s)
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstrasse 11, Munich, Germany
| | - Andrej Perdih
- National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia
| | - Sonja Đ Bauk
- Military Technical Institute, Ratka Resanovića 1, Belgrade, Serbia
| | - Tamara B Vujatović
- Faculty of Chemistry, University of Belgrade, Studentski Trg 12-16, Serbia
| | - Ilija N Cvijetić
- National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia; Innovation Center of The Faculty of Chemistry, University of Belgrade, Studentski Trg 12-16, Serbia
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11
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Fei Z, Hu M, Baum L, Kwan P, Hong T, Zhang C. The potential role of human multidrug resistance protein 1 (MDR1) and multidrug resistance-associated protein 2 (MRP2) in the transport of Huperzine A in vitro. Xenobiotica 2019; 50:354-362. [PMID: 31132291 DOI: 10.1080/00498254.2019.1623935] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Ziyan Fei
- School of Pharmacy, Nanchang University, Nanchang, PR China
- Provincial Key Laboratory for Drug Targeting and Drug Screening Research, Nanchang, PR China
| | - Mengyun Hu
- School of Pharmacy, Nanchang University, Nanchang, PR China
- Provincial Key Laboratory for Drug Targeting and Drug Screening Research, Nanchang, PR China
| | - Larry Baum
- The State Key Laboratory of Brain and Cognitive Sciences, University of Hong Kong, Pokfulam, Hong Kong, PR China
- Centre for Genomic Sciences, University of Hong Kong, Pokfulam, Hong Kong, PR China
| | - Patrick Kwan
- Department of Neuroscience, Alfred Hospital, Monash University, Melbourne, Australia
- Departments of Medicine and Neurology, Royal Melbourne Hospital, The University of Melbourne, Melbourne, Australia
| | - Tao Hong
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, PR China
| | - Chunbo Zhang
- School of Pharmacy, Nanchang University, Nanchang, PR China
- Provincial Key Laboratory for Drug Targeting and Drug Screening Research, Nanchang, PR China
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12
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Putra M, Sharma S, Gage M, Gasser G, Hinojo-Perez A, Olson A, Gregory-Flores A, Puttachary S, Wang C, Anantharam V, Thippeswamy T. Inducible nitric oxide synthase inhibitor, 1400W, mitigates DFP-induced long-term neurotoxicity in the rat model. Neurobiol Dis 2019; 133:104443. [PMID: 30940499 DOI: 10.1016/j.nbd.2019.03.031] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 02/22/2019] [Accepted: 03/28/2019] [Indexed: 11/26/2022] Open
Abstract
Chemical nerve agents (CNA) are increasingly becoming a threat to both civilians and military personnel. CNA-induced acute effects on the nervous system have been known for some time and the long-term consequences are beginning to emerge. In this study, we used diisopropylfluorophosphate (DFP), a seizurogenic CNA to investigate the long-term impact of its acute exposure on the brain and its mitigation by an inducible nitric oxide synthase (iNOS) inhibitor, 1400W as a neuroprotectant in the rat model. Several experimental studies have demonstrated that DFP-induced seizures and/or status epilepticus (SE) causes permanent brain injury, even after the countermeasure medication (atropine, oxime, and diazepam). In the present study, DFP-induced SE caused a significant increase in iNOS and 3-nitrotyrosine (3-NT) at 24 h, 48 h, 7d, and persisted for a long-term (12 weeks post-exposure), which led to the hypothesis that iNOS is a potential therapeutic target in DFP-induced brain injury. To test the hypothesis, we administered 1400W (20 mg/kg, i.m.) or the vehicle twice daily for the first three days of post-exposure. 1400W significantly reduced DFP-induced iNOS and 3-NT upregulation in the hippocampus and piriform cortex, and the serum nitrite levels at 24 h post-exposure. 1400W also prevented DFP-induced mortality in <24 h. The brain immunohistochemistry (IHC) at 7d post-exposure revealed a significant reduction in gliosis and neurodegeneration (NeuN+ FJB positive cells) in the 1400W-treated group. 1400W, in contrast to the vehicle, caused a significant reduction in the epileptiform spiking and spontaneous recurrent seizures (SRS) during 12 weeks of continuous video-EEG study. IHC of brain sections from the same animals revealed a significant reduction in reactive gliosis (both microgliosis and astrogliosis) and neurodegeneration across various brain regions in the 1400W-treated group when compared to the vehicle-treated group. A multiplex assay from hippocampal lysates at 6 weeks post-exposure showed a significant increase in several key pro-inflammatory cytokines/chemokines such as IL-1α, TNFα, IL-1β, IL-2, IL-6, IL-12, IL-17a, MCP-1, LIX, and Eotaxin, and a growth factor, VEGF in the vehicle-treated animals. 1400W significantly suppressed IL-1α, TNFα, IL-2, IL-12, and MCP-1 levels. It also suppressed DFP-induced serum nitrite levels at 6 weeks post-exposure. In the Morris water maze, the vehicle-treated animals spent significantly less time in the target quadrant in a probe trial at 9d post-exposure compared to their time spent in the same quadrant 11 days previously (i.e., 2 days prior to DFP exposure). Such a difference was not observed in the 1400W and control groups. However, learning and short-term memory were unaffected when tested at 10-16d and 28-34d post-exposure. Accelerated rotarod, horizontal bar test, and the forced swim test revealed no significant changes between groups. Overall, the findings from this study suggest that 1400W may be considered as a potential therapeutic agent as a follow-on therapy for CNA exposure, after controlling the acute symptoms, to prevent mortality and some of the long-term neurotoxicity parameters such as epileptiform spiking, SRS, neurodegeneration, reactive gliosis in some brain regions, and certain key proinflammatory cytokines and chemokine.
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Affiliation(s)
- Marson Putra
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States
| | - Shaunik Sharma
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States
| | - Meghan Gage
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States
| | | | - Andy Hinojo-Perez
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States
| | - Ashley Olson
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States
| | - Adriana Gregory-Flores
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States
| | - Sreekanth Puttachary
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, United States
| | - Chong Wang
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States
| | | | - Thimmasettappa Thippeswamy
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States.
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13
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Qu SM, Shan BH, Wang HT, Wang S. Lycodine type alkaloids from Lycopodiastrum casuarinoides with cytotoxic and cholinesterase inhibitory activities. Fitoterapia 2018; 131:86-90. [PMID: 30352296 DOI: 10.1016/j.fitote.2018.10.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 10/16/2018] [Accepted: 10/19/2018] [Indexed: 10/28/2022]
Abstract
A chemical investigation on the 70% EtOH extract of the aerial parts of Lycopodiastrum casuarinoides led to the isolation of six novel lycodine type alkaloids, lycocasuarines A-F (1-6). The structures of the isolated compounds were established based on 1D and 2D (1H1H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. The isolated alkaloids were tested in vitro for cytotoxic potentials against seven malignant melanoma cell lines as well as acetylcholinesterase (AChE) and butyrocholinesterase (BuChE) inhibitory activities. As a result, alkaloids 1 and 3 exhibited significant cytotoxic activities against all the tested tumor cell lines with IC50 values <10 μM and the inhibitory activities for AchE (0.94 ± 0.15 and 0.24 ± 0.03 μM, respectively) and BuchE (1.82 ± 0.12 and 7.31 ± 0.42 μM, respectively).
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Affiliation(s)
- Sheng-Ming Qu
- Department of Dermatology, Second Hospital of Jilin University, Changchun 130041, China
| | - Bai-Hui Shan
- Department of Dermatology, Second Hospital of Jilin University, Changchun 130041, China
| | - Hai-Tao Wang
- Department of E.N.T., Second Hospital of Jilin University, Changchun 130041, China
| | - Shuang Wang
- Department of Dermatology, Second Hospital of Jilin University, Changchun 130041, China.
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14
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Bajgar J. Complex View on Poisoning with Nerve Agents and Organophosphates. ACTA MEDICA (HRADEC KRÁLOVÉ) 2018. [DOI: 10.14712/18059694.2018.23] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
OP/nerve agents are still considered as important chemicals acting on living organisms and widely used in human practice. Nerve agents are the most lethal chemical warfare agents. They are characterized according to their action as compounds influencing cholinergic nerve transmission via inhibition of AChE. The symptoms of intoxication comprise nicotinic, muscarinic and central symptoms, for some OP/nerve agents, a delayed neurotoxicity is observed. Cholinesterases (AChE and BuChE) are characterized as the main enzymes involved in the toxic effect of these compounds including their molecular forms. The activity of both enzymes (and molecular forms) is influenced by inhibitors and other factors such as pathological states. There are different methods for cholinesterase determination, however, the most frequent is the method based on the hydrolysis of thiocholine esters and following detection of free SH-group of the released thiocholine. The diagnosis of OP/nerve agents poisoning is based on anamnesis, the clinical status of the intoxicated organism and on cholinesterase determination in the blood. Some principles of prophylaxis against OP/nerve agents poisoning comprising the administration of reversible cholinesterase inhibitors such as pyridostigmine (alone or in combination with other drugs), scavengers such as preparations of cholinesterases, some therapeutic drugs and possible combinations are given. Basic principles of the treatment of nerve agents/OP poisoning are described. New drugs for the treatment are under experimental study based on new approaches to the mechanism of action.
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Liu Y, Xu PS, Ren Q, Chen X, Zhou G, Li D, Li XM, Xu KP, Yu X, Tan GS. Lycodine-type alkaloids from Lycopodiastrum casuarinoides and their cholinesterase inhibitory activities. Fitoterapia 2018; 130:203-209. [PMID: 30213757 DOI: 10.1016/j.fitote.2018.09.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/05/2018] [Accepted: 09/08/2018] [Indexed: 11/27/2022]
Abstract
Four new trace alkaloids with lycodine-related structures, Lycocasuarinines A-D (1-4), together with seven known analogues (5-11), were isolated from the chloroform extract of Lycopodiastrum casuarinoides. The structures and stereochemistry of 1-4 were elucidated by spectroscopic analysis (IR, UV, MS, NMR, HRESIMS and CD) and comparison with known ones. The acetylcholinesterase (AChE) and butyrocholinesterase (BuChE) inhibitory activities of nine isolates were evaluated. Lycocasuarinine D (4) showed the most potent AChE inhibitory effect. In addition, a plausible biogenetic pathway of compound 4 was proposed.
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Affiliation(s)
- Yang Liu
- Xiangya Hospital of Central South University, Changsha 410008, PR China
| | - Ping-Sheng Xu
- Xiangya Hospital of Central South University, Changsha 410008, PR China
| | - Qin Ren
- Xiangya Hospital of Central South University, Changsha 410008, PR China
| | - Xi Chen
- Xiangya Hospital of Central South University, Changsha 410008, PR China
| | - Gan Zhou
- Xiangya Hospital of Central South University, Changsha 410008, PR China
| | - Dan Li
- Xiangya Hospital of Central South University, Changsha 410008, PR China
| | - Xiao-Min Li
- Xiangya Hospital of Central South University, Changsha 410008, PR China
| | - Kang-Ping Xu
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, PR China
| | - Xia Yu
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, PR China
| | - Gui-Shan Tan
- Xiangya Hospital of Central South University, Changsha 410008, PR China; Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, PR China.
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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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Lorke DE, Petroianu GA. Reversible cholinesterase inhibitors as pretreatment for exposure to organophosphates. A review. J Appl Toxicol 2018; 39:101-116. [PMID: 30027640 DOI: 10.1002/jat.3662] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 06/06/2018] [Indexed: 01/04/2023]
Abstract
Organophosphorus compounds (OPCs), inhibitors of acetylcholinesterase (AChE), are useful agents as pesticides, but also represent a serious health hazard. Standard therapy with atropine and established oxime-type enzyme reactivators (pralidoxime, obidoxime) is unsatisfactory. Better therapeutic results are obtained, when reversible AChE inhibitors are administered before OPC exposure. This review summarizes the history of such a pretreatment approach and sums up a set of experiments undertaken in search of compounds that are efficacious when given before a broad range of OPCs. The prophylactic efficacy of 10 known AChE inhibitors, either already used clinically for different indications (physostigmine, pyridostigmine, ranitidine, tiapride, tacrine, amiloride, metoclopramide, methylene blue) or developed for possible therapeutic use in the future (7-methoxytacrine, K-27) was compared, when administered before exposure to six chemically diverse OPCs in the same experimental setting: ethyl-paraoxon, methyl-paraoxon, diisopropylfluorophosphate, terbufos sulfone, azinphos-methyl and dicrotophos. The experimental oxime K-27 was the most efficacious compound, affording best protection, when administered before terbufos sulfone, azinphos-methyl and dicrotophos, second best before ethyl- and methyl-paraoxon exposure and third best before diisopropylfluorophosphate administration. This ranking was similar to that of physostigmine, which was superior to the Food and Drug Administration-approved pretreatment for soman with pyridostigmine. Tiapride, amiloride, metoclopramide, methylene blue and 7-methoxytacrine did not achieve protection. No correlation was observed between the IC50 of the reversible AChE inhibitors and their protective efficacy. These studies indicate that K-27 can be considered a very promising broad-spectrum prophylactic agent in case of imminent organophosphate exposure, which may be related to its AChE reactivating activity rather than its AChE inhibition.
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Affiliation(s)
- Dietrich E Lorke
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Georg A Petroianu
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
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Recent progress in repositioning Alzheimer's disease drugs based on a multitarget strategy. Future Med Chem 2016; 8:2113-2142. [PMID: 27774814 DOI: 10.4155/fmc-2016-0103] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Alzheimer's disease (AD) is a serious progressive neurological disorder, characterized by impaired cognition and profound irreversible memory loss. The multifactorial nature of AD and the absence of a cure so far have stimulated medicinal chemists worldwide to follow multitarget drug-design strategies based on repositioning approved drugs. This review describes a summary of recently published works focused on tailoring new derivatives of US FDA-approved acetylcholinesterase inhibitors, in addition to huperzine (a drug approved in China), either by hybridization with other pharmacophore elements (to hit more AD targets), or by combination of two FDA-approved drugs. Besides the capacity for improving the cholinergic activity, these polyfunctional derivatives are also able to tackle other important neuroprotective properties, such as anti-β-amyloid aggregation, scavenging of radical oxygen species, modulation of redox-active metals or inhibition of monoamine oxidase, thereby resulting in potentially novel and more effective therapeutics for the treatment of AD.
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Zebrafish is a predictive model for identifying compounds that protect against brain toxicity in severe acute organophosphorus intoxication. Arch Toxicol 2016; 91:1891-1901. [PMID: 27655295 PMCID: PMC5364264 DOI: 10.1007/s00204-016-1851-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 09/15/2016] [Indexed: 12/13/2022]
Abstract
Acute organophosphorus (OP) intoxication is a worldwide clinical and public health problem. In addition to cholinergic crisis, neurodegeneration and brain damage are hallmarks of the severe form of this toxidrome. Recently, we generated a chemical model of severe acute OP intoxication in zebrafish that is characterized by altered head morphology and brain degeneration. The pathophysiological pathways resulting in brain toxicity in this model are similar to those described in humans. The aim of this study was to assess the predictive power of this zebrafish model by testing the effect of a panel of drugs that provide protection in mammalian models. The selected drugs included “standard therapy” drugs (atropine and pralidoxime), reversible acetylcholinesterase inhibitors (huperzine A, galantamine, physostigmine and pyridostigmine), N-methyl-d-aspartate (NMDA) receptor antagonists (MK-801 and memantine), dual-function NMDA receptor and acetylcholine receptor antagonists (caramiphen and benactyzine) and anti-inflammatory drugs (dexamethasone and ibuprofen). The effects of these drugs on zebrafish survival and the prevalence of abnormal head morphology in the larvae exposed to 4 µM chlorpyrifos oxon [1 × median lethal concentration (LC50)] were determined. Moreover, the neuroprotective effects of pralidoxime, memantine, caramiphen and dexamethasone at the gross morphological level were confirmed by histopathological and transcriptional analyses. Our results demonstrated that the zebrafish model for severe acute OP intoxication has a high predictive value and can be used to identify new compounds that provide neuroprotection against severe acute OP intoxication.
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Maraković N, Knežević A, Vinković V, Kovarik Z, Šinko G. Design and synthesis of N-substituted-2-hydroxyiminoacetamides and interactions with cholinesterases. Chem Biol Interact 2016; 259:122-132. [PMID: 27238725 DOI: 10.1016/j.cbi.2016.05.035] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 04/20/2016] [Accepted: 05/25/2016] [Indexed: 11/27/2022]
Abstract
Within this study, we designed and synthesized four new oxime compounds of the N-substituted 2-hydroxyiminoacetamide structure and evaluated their interactions with acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Our aim was to explore the possibility of extending the dual-binding mode of interaction between the enzyme and the inhibitor to a so-called triple-binding mode of interaction through the introduction of an additional binding moiety. N-substituted 2-hydroxyiminoacetamide 1 was prepared via BOP catalyzed amidation of hydroxyiminoacetic acid with 3-azido-1-phenylpropylamine. An azide group enabled us to prepare more elaborate structures 2-4 by the copper-catalyzed azide-alkyne cycloaddition. The new compounds 1-4 differed in their presumed AChE peripheral site binding moiety, which ranged from an azide group to functionalized heterocycles. Molecular docking studies revealed that all three binding moieties are involved in the non-covalent interactions with ChEs for all of the four compounds, albeit not always in the complete accordance with the proposed hypothesis. All of the four compounds reversibly inhibited the ChEs with their inhibition potency increasing in the same order for both enzymes (1 < 2 < 4 < 3). A higher preference for binding to BChE (KI from 0.30 μmol/L to 130 μmol/L) over AChE (KI from 50 μmol/L to 1200 μmol/L) was observed for all of the compounds. Compounds were screened for reactivation of cyclosarin-, sarin- and VX-inhibited AChE and BChE.
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Affiliation(s)
- Nikola Maraković
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10 000 Zagreb, Croatia
| | | | - Vladimir Vinković
- Ruđer Bošković Institute, Bijenička cesta 54, HR-10 000 Zagreb, Croatia
| | - Zrinka Kovarik
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10 000 Zagreb, Croatia
| | - Goran Šinko
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10 000 Zagreb, Croatia.
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Pretreatment with Huperzine A-Loaded Poly(lactide-co-glycolide) Nanoparticles Protects against Lethal Effects of Soman-Induced in Mice. ACTA ACUST UNITED AC 2015. [DOI: 10.4028/www.scientific.net/kem.645-646.1374] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Huperzine A (HupA), an alkaloid isolated from theChinese club moss, is a reversible inhibitor of cholinesterases which cross the blood-brain barrier and show high specificity for acetylcholinesterase (AChE). However, HupA induces unwanted side effects in an effective dose against nerve agent poisoning. In the present study, HupA–loaded poly (lactide-co-glycolide) nanoparticles (HupA-PLGA-NP) were prepared using the O/W emulsion solvent evaporation method. The results of SEM demonstrated that HupA-PLGA-NP had an spherical shape and a smooth surface without pores. It’s mean diameter and PDI were 208.5±3.6nm and 0.09±0.01 respectively. The Zeta potential was-35.3±1.8mV and the drug loading was 2.86±0.6%.In vitrodrug release studies showed that HupA-PLGA-NP had a sustained-release behavior in phosphate buffer solution, The accumulated amount of HupA was about 72.1% at 48h with a low burst release within 30min. The LD50values of HupA and HupA-PLGA-NP were 1.40 and 4.85mg/kg respectively, showing that the toxicity of HupA was reduced by 3.5 times. We evaluated the protective efficacy for different doses of HupA or HupA-PLGA-NP against 1.0×LD95(143.0μg/kg) soman toxicity. The results confirmed that HupA (0.3~0.5mg/kg) or HupA-PLGA-NP (0.5~1.5mg/kg) could ensure animals survive. However, about 10% of the animals injected with HupA (0.8mg/kg) died, while no animals died when injected with HupA-PLGA-NP (1.5mg/kg). Aim to 100% survival rate, the effective protective time (12h) of HupA-PLGA-NP (0.5mg/kg,iv) against 1.0×LD95soman toxicity in mice was significantly prolonged compared with that of HupA (4h). The study of AChE activity showed that whole-blood and supernatant of brain diluted by 80-fold and 10-fold respectively were optimum in this study. AChE inhibition after administration of HupA and HupA-PLGA-NP (0.5mg/kg,iv) was recorded and analyzed, The peak values of AChE inhibition in whole-blood and brain by HupA-PLGA-NP (17.6% and 21.8%) were lower than those by HupA (33.7% and 31.9%) and AChE inhibition time by HupA-PLGA-NP was longer than that by HupA. These data confirmed that HupA-PLGA-NP had less toxic and more longer time than HupA against 1.0×LD95soman poisoning and warrant further development as a potent medical countermeasure against chemical warfare nerve agents (CWNAs) poisoning.
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Bajgar J, Cabal J, Kassa J, Pavlík M. Natural Detoxification Capacity to Inactivate Nerve Agents Sarin and VX in the Rat Blood. ACTA MEDICA (HRADEC KRÁLOVÉ) 2015; 58:128-30. [PMID: 26960825 DOI: 10.14712/18059694.2016.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND The method of continual determination of the rat blood cholinesterase activity was developed to study the changes of the blood cholinesterases following different intervetions. AIMS The aim of this study is registration of cholinesterase activity in the rat blood and its changes to demonstrate detoxification capacity of rats to inactivate sarin or VX in vivo. METHODS The groups of female rats were premedicated (ketamine and xylazine) and cannulated to a. femoralis. Continual blood sampling (0.02 ml/min) and monitoring of the circulating blood cholinesterase activity were performed. Normal activity was monitored 1-2 min and then the nerve agent was administered i.m. (2×LD50). Using different time intervals of the leg compression and relaxation following the agent injection, cholinesterase activity was monitored and according to the inhibition obtained, detoxification capacity was assessed. RESULTS Administration of sarin to the leg, then 1 and 5 min compression and 20 min later relaxation showed that further inhibition in the blood was not observed. On the other hand, VX was able to inhibit blood cholinesterases after this intervention. CONCLUSIONS The results demonstrated that sarin can be naturally detoxified on the contrary to VX. Described method can be used as model for other studies dealing with changes of cholinesterases in the blood following different factors.
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Affiliation(s)
- Jiří Bajgar
- Biomedical Research Center, University Hospital Hradec Králové, Hradec Králové, Czech Republic. .,Center for Basic and Applied Research, Faculty of Informatics and Management, University of Hradec Králové, Hradec Králové, Czech Republic.
| | - Jiří Cabal
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Králové, Czech Republic
| | - Jiří Kassa
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Králové, Czech Republic
| | - Michal Pavlík
- Department of Teaching Support, Faculty of Military Health Sciences, University of Defence, Hradec Králové, Czech Republic
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Petroianu GA, Nurulain SM, Hasan MY, Kuča K, Lorke DE. Reversible cholinesterase inhibitors as pre-treatment for exposure to organophosphates: assessment using azinphos-methyl. J Appl Toxicol 2014; 35:493-9. [PMID: 25186309 DOI: 10.1002/jat.3052] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 06/30/2014] [Accepted: 07/01/2014] [Indexed: 01/22/2023]
Abstract
Pre-treatment with reversible acetylcholinesterase (AChE) inhibitors before organophosphorous compound (OPC) exposure can reduce OPC-induced mortality. However, pyridostigmine, the only substance employed for such prophylaxis, is merely efficacious against a limited number of OPCs. In search of more efficacious and broad-range alternatives, we have compared in vivo the ability of five reversible AChE inhibitors (pyridostigmine, physostigmine, ranitidine, tacrine and K-27) to reduce mortality induced by the OPC azinphos-methyl. Protection was quantified using Cox analysis by determining the relative risk (RR) of death in rats that were administered these AChE inhibitors in equitoxic dosage (25% of LD01) 30 min before azinphos-methyl exposure. Azinphos-methyl-induced mortality was significantly reduced by all five tested compounds as compared with the reference group that was only exposed to azinphos-methyl without prior pre-treatment (RR = 1). The most efficacious prophylactic agents were K-27 (RR = 0.15) and physostigmine (RR = 0.21), being significantly more efficacious than ranitidine (RR = 0.62) and pyridostigmine (RR = 0.37). Pre-treatment with tacrine (RR = 0.29) was significantly more efficacious than pre-treatment with ranitidine, but the difference between tacrine and pyridostigmine was not significant. Our results indicate that prophylactic administration of the oxime K-27 may be a promising alternative in cases of imminent OPC exposure.
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Affiliation(s)
- Georg A Petroianu
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, Florida International University, University Park GL 495 D, 11200 SW 8th St, Miami, FL 33199, Florida, USA; Department of Pharmacology & Therapeutics, FMHS, UAE University, Al Ain, United Arab Emirates
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Lorke DE, Nurulain SM, Hasan MY, Kuča K, Petroianu GA. Prophylactic administration of non-organophosphate cholinesterase inhibitors before acute exposure to organophosphates: assessment using terbufos sulfone. J Appl Toxicol 2013; 34:1096-103. [PMID: 24136594 DOI: 10.1002/jat.2939] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 09/04/2013] [Accepted: 09/04/2013] [Indexed: 01/03/2023]
Abstract
Poisoning with organophosphorus compounds (OPCs) poses a serious threat worldwide. OPC-induced mortality can be significantly reduced by prophylactic administration of reversible acetylcholinesterase (AChE) inhibitors. The only American Food and Drug Administration (FDA)-approved substance for such pre-treatment (to soman exposure) is presently pyridostigmine, although its efficacy is controversial. In search for more efficacious and broad-spectrum alternatives, we have assessed in vivo the mortality-reducing efficacy of a group of five compounds with known AChE inhibitory activity (pyridostigmine, physostigmine, ranitidine, tacrine and K-27), when given in equitoxic dosage (25% of LD01 ) 30 min before exposure to the OPC terbufos sulfone. Protection was quantified in rats by determining the relative risk of death (RR) using Cox analysis, with RR = 1 for animals given only terbufos sulfone, but no pre-treatment. All tested AChE inhibitors reduced terbufos sulfone-induced mortality significantly (p ≤ 0.05) as compared with the non-treatment group (RR = 1: terbufos sulfone only). Best in vivo protection from terbufos sulfone-induced mortality was achieved, when K-27 was given before terbufos sulfone exposure (RR = 0.06), which was significantly (P ≤ 0.05) superior to the pre-treatment with all other tested compounds, for example tacrine (RR = 0.21), pyridostigmine (RR = 0.28), physostigmine (RR = 0.29) and ranitidine (RR = 0.33). The differences in efficacy between tacrine, pyridostigmine, physostigmine and ranitidine were not statistically significant. Prophylactic administration of an oxime (such as K-27) in case of imminent OPC exposure may be a viable option.
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Affiliation(s)
- Dietrich E Lorke
- Department of Cellular Biology & Pharmacology, Florida International University, Miami, Florida, USA; Department of Anatomy, FMHS, UAE University, Al Ain, United Arab Emirates
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Nachon F, Brazzolotto X, Trovaslet M, Masson P. Progress in the development of enzyme-based nerve agent bioscavengers. Chem Biol Interact 2013; 206:536-44. [PMID: 23811386 DOI: 10.1016/j.cbi.2013.06.012] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 06/15/2013] [Accepted: 06/18/2013] [Indexed: 11/17/2022]
Abstract
Acetylcholinesterase is the physiological target for acute toxicity of nerve agents. Attempts to protect acetylcholinesterase from phosphylation by nerve agents, is currently achieved by reversible inhibitors that transiently mask the enzyme active site. This approach either protects only peripheral acetylcholinesterase or may cause side effects. Thus, an alternative strategy consists in scavenging nerve agents in the bloodstream before they can reach acetylcholinesterase. Pre- or post-exposure administration of bioscavengers, enzymes that neutralize and detoxify organophosphorus molecules, is one of the major developments of new medical counter-measures. These enzymes act either as stoichiometric or catalytic bioscavengers. Human butyrylcholinesterase is the leading stoichiometric bioscavenger. Current efforts are devoted to its mass production with care to pharmacokinetic properties of the final product for extended lifetime. Development of specific reactivators of phosphylated butyrylcholinesterase, or variants with spontaneous reactivation activity is also envisioned for rapid in situ regeneration of the scavenger. Human paraoxonase 1 is the leading catalytic bioscavenger under development. Research efforts focus on improving its catalytic efficiency toward the most toxic isomers of nerve agents, by means of directed evolution-based strategies. Human prolidase appears to be another promising human enzyme. Other non-human efficient enzymes like bacterial phosphotriesterases or squid diisopropylfluorophosphatase are also considered though their intrinsic immunogenic properties remain challenging for use in humans. Encapsulation, PEGylation and other modifications are possible solutions to address this problem as well as that of their limited lifetime. Finally, gene therapy for in situ generation and delivery of bioscavengers is for the far future, but its proof of concept has been established.
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Affiliation(s)
- Florian Nachon
- Institut de Recherche Biomédicale des Armées, BP87, 38702 La Tronche Cédex, France.
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Wang Y, Wei Y, Oguntayo S, Doctor BP, Nambiar MP. A combination of [+] and [-]-Huperzine A improves protection against soman toxicity compared to [+]-Huperzine A in guinea pigs. Chem Biol Interact 2012; 203:120-4. [PMID: 23123250 DOI: 10.1016/j.cbi.2012.10.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 10/10/2012] [Accepted: 10/15/2012] [Indexed: 01/01/2023]
Abstract
The neuropathologic mechanisms after exposure to lethal doses of nerve agent are complex and involve multiple biochemical pathways. Effective treatment requires drugs that can simultaneously protect by reversible binding to the acetylcholinesterase (AChE) and blocking cascades of seizure related brain damage, inflammation, neuronal degeneration as well as promoting induction of neuroregeneration. [-]-Huperzine A ([-]-Hup A), is a naturally occurring potent reversible AChE inhibitor that penetrates the blood-brain barrier. It also has several neuroprotective effects including modification of beta-amyloid peptide, reduction of oxidative stress, anti-inflammatory, anti-apoptotic and induction and regulation of nerve growth factor. Toxicities at higher doses restrict the neuroporotective ability of [-]-Hup A for treatment. The synthetic stereoisomer, [+]-Hup A, is less toxic due to poor AChE inhibition and is suitable for both pre-/post-exposure treatments of nerve agent toxicity. [+]-Hup A block the N-methyl-D-aspartate (NMDA)-induced seizure in rats, reduce excitatory amino acid induced neurotoxicity and also prevent soman induced toxicity with minimum performance decrement. Unique combinations of two stereo-isomers of Hup A may provide an excellent pre/post-treatment drug for the nerve agent induced seizure/status epilepticus. We investigated a combination of [+]-Hup A with a small dose of [-]-Hup A ([+] and [-]-Hup A) against soman toxicity. Our data showed that pretreatment with a combination [+] and [-]-Hup A significantly increased the survival rate and reduced behavioral abnormalities after exposure to 1.2 × LD(50) soman compared to [+]-Hup A in guinea pigs. In addition, [+] and [-]-Hup A pretreatment inhibited the development of high power of EEG better than [+]-Hup A pretreatment alone. These data suggest that a combination of [+] and [-]-Hup A offers better protection than [+]-Hup A and serves as a potent medical countermeasure against lethal dose nerve agent toxicity in guinea pigs.
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Affiliation(s)
- Ying Wang
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
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Affiliation(s)
- Maung Kyaw Moe Tun
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United
States
| | - Seth B. Herzon
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United
States
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Abstract
(−)-Huperzine A (1) is an alkaloid isolated from a Chinese club moss. Due to its potent neuroprotective activities, it has been investigated as a candidate for the treatment of neurodegenerative diseases, including Alzheimer’s disease. In this review, we will discuss the pharmacology and therapeutic potential of (−)-huperzine A (1). Synthetic studies of (−)-huperzine A (1) aimed at enabling its development as a pharmaceutical will be described.
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Affiliation(s)
| | - Seth B Herzon
- Department of Chemistry, Yale University, New Haven, CT, USA
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Petroianu GA, Nurulain SM, Shafiullah M, Hasan MY, Kuča K, Lorke DE. Usefulness of administration of non-organophosphate cholinesterase inhibitors before acute exposure to organophosphates: assessment using paraoxon. J Appl Toxicol 2012; 33:894-900. [PMID: 22611016 DOI: 10.1002/jat.2760] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 02/28/2012] [Accepted: 02/28/2012] [Indexed: 11/11/2022]
Abstract
Reversible acetylcholinesterase (AChE) inhibitors can protect against the lethal effects of irreversible organophosphorus AChE inhibitors (OPCs), when administered before OPC exposure. We have assessed in vivo the mortality-reducing efficacy of a group of known AChE inhibitors, when given in equitoxic dosage before exposure to the OPC paraoxon. Protection was quantified in rats by determining the relative risk (RR) of death. Best in vivo protection from paraoxon-induced mortality was observed after prophylactic administration of physostigmine (RR = 0.30) or the oxime K-27 (RR = 0.34); both treatments were significantly superior to the pre-treatment with all other tested compounds, including the established substance pyridostigmine. Tacrine (RR = 0.67), ranitidine (RR = 0.72), pyridostigmine (RR = 0.76), tiapride (RR = 0.80) and 7-MEOTA (RR = 0.86) also significantly reduced the relative risk of paraoxon-induced death, but to a lesser degree. Methylene blue, amiloride and metoclopramide had an unfavorable effect (RR ≥ 1), significantly increasing mortality. When CNS penetration by prophylactic is undesirable K-27 is a promising alternative to pyridostigmine.
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Affiliation(s)
- Georg A Petroianu
- Department of Cellular Biology & Pharmacology, Florida International University, Miami, FL 33199, USA.
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Non-enzymatic pretreatment of nerve agent (soman) poisoning: A brief state-of-the-art review. Toxicol Lett 2011; 206:35-40. [DOI: 10.1016/j.toxlet.2011.04.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 04/20/2011] [Indexed: 11/21/2022]
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The present approaches to the development of prophylactic and therapeutic antidotes against nerve agents. Interdiscip Toxicol 2011; 1:18-21. [PMID: 21218100 PMCID: PMC2993476 DOI: 10.2478/v10102-010-0026-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 05/09/2008] [Accepted: 05/12/2008] [Indexed: 11/21/2022] Open
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Diet composition exacerbates or attenuates soman toxicity in rats: implied metabolic control of nerve agent toxicity. Neurotoxicology 2011; 32:342-9. [PMID: 21396400 DOI: 10.1016/j.neuro.2011.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 02/03/2011] [Accepted: 03/02/2011] [Indexed: 01/15/2023]
Abstract
To evaluate the role of diet composition on nerve agent toxicity, rats were fed four distinct diets ad libitum for 28 d prior to challenge with 110 μg/kg (1.0 LD(50), sc) soman. The four diets used were a standard rodent diet, a choline-enriched diet, a glucose-enriched diet, and a ketogenic diet. Body weight was recorded throughout the study. Toxic signs and survival were evaluated at key times for up to 72 h following soman exposure. Additionally, acquisition of discriminated shuttlebox avoidance performance was characterized beginning 24h after soman challenge and across the next 8 d (six behavioral sessions). Prior to exposure, body weight was highest in the standard diet group and lowest in the ketogenic diet group. Upon exposure, differences in soman toxicity as a function of diet became apparent within the first hour, with mortality in the glucose-enriched diet group reaching 80% and exceeding all other groups (in which mortality ranged from 0 to 6%). At 72 h after exposure, mortality was 100% in the glucose-enriched diet group, and survival approximated 50% in the standard and choline-enriched diet groups, but equaled 87% in the ketogenic diet group. Body weight loss was significantly reduced in the ketogenic and choline-enriched diet groups, relative to the standard diet group. At 1 and 4h after exposure, rats in the ketogenic diet group had significantly lower toxic sign scores than all other groups. The ketogenic diet group performed significantly better than the standard diet group on two measures of active avoidance performance. The exacerbated soman toxicity observed in the glucose-enriched diet group coupled with the attenuated soman toxicity observed in the ketogenic diet group implicates glucose availability in the toxic effects of soman. This increased glucose availability may enhance acetylcholine synthesis and/or utilization, thereby exacerbating peripheral and central soman toxicity.
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Tun MKM, Wüstmann DJ, Herzon SB. A robust and scalable synthesis of the potent neuroprotective agent (−)-huperzine A. Chem Sci 2011. [DOI: 10.1039/c1sc00455g] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Malkova L, Kozikowski AP, Gale K. The effects of huperzine A and IDRA 21 on visual recognition memory in young macaques. Neuropharmacology 2010; 60:1262-8. [PMID: 21185313 DOI: 10.1016/j.neuropharm.2010.12.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 11/29/2010] [Accepted: 12/15/2010] [Indexed: 11/26/2022]
Abstract
Nootropic agents or cognitive enhancers are purported to improve mental functions such as cognition, memory, or attention. The aim of our study was to determine the effects of two possible cognitive enhancers, huperzine A and IDRA 21, in normal young adult monkeys performing a visual memory task of varying degrees of difficulty. Huperzine A is a reversible acetylcholinesterase (AChE) inhibitor, its administration results in regionally specific increases in acetylcholine levels in the brain. In human clinical trials, Huperzine A resulted in cognitive improvement in patients with mild to moderate form of Alzheimer's disease (AD) showing its potential as a palliative agent in the treatment of AD. IDRA 21 is a positive allosteric modulator of glutamate AMPA receptors. It increases excitatory synaptic strength by attenuating rapid desensitization of AMPA receptors and may thus have beneficial therapeutic effects to ameliorate memory deficits in patients with cognitive impairments, including AD. The present study evaluated the effects of the two drugs in normal, intact, young adult monkeys to determine whether they can result in cognitive enhancement in a system that is presumably functioning optimally. Six young pigtail macaques (Macaca nemestrina) were trained on delayed non-matching-to-sample task, a measure of visual recognition memory, up to criterion of 90% correct responses on each of the four delays (10s, 30s, 60s, and 90s). They were then tested on two versions of the task: Task 1 included the four delays intermixed within a session and the monkeys performed it with the accuracy of 90%. Task 2 included, in each of 24 trials, a list of six objects presented in succession. Two objects from the list were then presented for choice paired with novel objects and following two of the four delays intermixed within a session. This task with a higher mnemonic demand yielded an average performance of 64% correct. Oral administration of huperzine A did not significantly affect the monkeys' performance on either task. However, a significant negative correlation was found between the baseline performance on each delay and the change in performance under huperzine A, suggesting that under conditions in which the subjects were performing poorly (55-69%), the drug resulted in improved performance, whereas no improvement was obtained when the baseline was close to 90%. In fact, when the subjects were performing very well, huperzine A tended to reduce the performance accuracy, indicating that in a system that functions optimally, the increased availability of acetylcholine does not improve performance or memory, especially when the animals are close to the maximum performance. In contrast, oral administration of IDRA 21 significantly improved performance on Task 2, especially on the longest delay. This finding supports the potential use of this drug in treatment of cognitive and memory disorders. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'.
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Affiliation(s)
- Ludise Malkova
- Department of Pharmacology and the Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, 3900 Reservoir Rd. NW, Washington, DC 20007, USA.
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Musilek K, Roder J, Komloova M, Holas O, Hrabinova M, Pohanka M, Dohnal V, Opletalova V, Kuca K, Jung YS. Preparation, in vitro screening and molecular modelling of symmetrical 4-tert-butylpyridinium cholinesterase inhibitors--analogues of SAD-128. Bioorg Med Chem Lett 2010; 21:150-4. [PMID: 21144749 DOI: 10.1016/j.bmcl.2010.11.051] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 11/06/2010] [Accepted: 11/09/2010] [Indexed: 10/18/2022]
Abstract
Carbamate inhibitors (e.g., pyridostimine bromide) are used as a pre-exposure treatment for the prevention of organophosphorus poisoning. They work by blocking acetylcholinesterase's (AChE) native function and thus protect AChE against irreversible inhibition by organophosphorus compounds. However, carbamate inhibitors are known for many undesirable side-effects related to the carbamylation of AChE. In this Letter, 19 analogues of SAD-128 were prepared and evaluated as cholinesterase inhibitors. The screening results showed promising inhibitory ability of four compounds better to used standards (pralidoxime, obidoxime, BW284c51, ethopropazine, SAD-128). Four most promising compounds were selected for further molecular docking studies. The SAR was stated from obtained data. The former receptor studies were reported and discussed. The further in vivo studies were recommended in the view of OP pre-exposure treatment.
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Affiliation(s)
- Kamil Musilek
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
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36
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Lorke DE, Hasan MY, Nurulain SM, Shafiullah M, Kuča K, Petroianu GA. Pretreatment for acute exposure to diisopropylfluorophosphate: in vivo efficacy of various acetylcholinesterase inhibitors. J Appl Toxicol 2010; 31:515-23. [PMID: 20981864 DOI: 10.1002/jat.1589] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 08/18/2010] [Accepted: 08/19/2010] [Indexed: 11/06/2022]
Abstract
Prophylactic administration of reversible acetylcholinesterase (AChE) inhibitors before exposure to organophosphorus compounds (OPCs) can reduce OPC-induced mortality. Pyridostigmine is the only FDA-approved substance for such use. The AChE-inhibitory activity of known AChE inhibitors was quantified in vitro and their in vivo mortality-reducing efficacy was compared, when given prophylactically before the exposure to the OPC diisopropylfluorophosphate (DFP). The IC50 was measured in vitro for the known AChE inhibitors pyridostigmine, physostigmine, ranitidine, tiapride, tacrine, 7-methoxytacrine, amiloride, metoclopramide, methylene blue and the experimental oxime K-27. Their in vivo efficacy, when given as pretreatment, to protect rats from DFP-induced mortality was quantified by determining the relative risk of death (RR) by Cox analysis, with RR = 1 for animals given only DFP, but no pretreatment. Physostigmine was the strongest in vitro AChE-inhibitor (IC50 = 0.012 µ m), followed by 7-methoxytacrine, tacrine, pyridostigmine and methylene blue. Ranitidine (IC50 = 2.5 µ m), metoclopramide and amiloride were in the mid-range. Tiapride (IC50 = 256 µ m) and K-27 (IC50 = 414 µ m) only weakly inhibited RBC AChE activity. Best in vivo protection from DFP-induced mortality was achieved when physostigmine (RR = 0.02) or tacrine (RR = 0.05) was given before DFP exposure, which was significantly superior to the pretreatment with all other tested compounds, except K-27 (RR = 0.18). The mortality-reducing effect of pyridostigmine, ranitidine and 7-methoxytacrine was inferior, but still significant. Tiapride, methylene blue, metoclopramide and amiloride did not significantly improve DFP-induced mortality. K-27 may be a more efficacious alternative to pyridostigmine, when passage into the brain precludes administration of physostigmine or tacrine.
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Affiliation(s)
- Dietrich E Lorke
- Department of Anatomy, FMHS, UAE University, Al Ain, UAE; Department of Cellular Biology and Pharmacology, Florida International University, Miami, FL, USA
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Berend S, Katalinić M, Vrdoljak AL, Kovarik Z, Kuca K, Radić B. In vivo experimental approach to treatment against tabun poisoning. J Enzyme Inhib Med Chem 2010; 25:531-6. [PMID: 20235800 DOI: 10.3109/14756360903357593] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Organophosphorus compounds pose a potential threat to both military and civilian populations. Since post-exposure therapy has its limitations, our research was focused on the possibility of improving pretreatment in order to limit the toxic effects of tabun. We determined the protective index of various combinations of atropine, oximes (K074, K048, and TMB-4), and pyridostigmine given to mice before tabun intoxication. Although the tested oximes showed very good therapeutic efficacy in tabun-poisoned mice, the given pretreatments improved therapy against tabun poisoning. These regimens ensured survival of all animals up to 25.2 LD(50) of tabun. Our results indicate that even pretreatment with atropine alone is sufficiently effective in enhancing the survival of mice poisoned by multiple doses of tabun, if oxime therapy follows. K048 is our oxime of choice for future research, as it shows better protective and reactivating potency.
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Affiliation(s)
- Suzana Berend
- Institute for Medical Research and Occupational Health, Ksaverska c. 2, Zagreb, Croatia.
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38
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Lorke DE, Hasan MY, Nurulain SM, Kuca K, Schmitt A, Petroianu GA. Efficacy of two new asymmetric bispyridinium oximes (K-27 and K-48) in rats exposed to diisopropylfluorophosphate: comparison with pralidoxime, obidoxime, trimedoxime, methoxime, and HI-6. Toxicol Mech Methods 2009; 19:327-33. [PMID: 19778224 DOI: 10.1080/15376510902798695] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Introduction. The new K-oximes, K-27 [1-(4-hydroxyimino-methylpyridinium)-4-(4-carbamoylpyridinium) propane dibromide] and K-48 [1-(4-hydroxyimino-methylpyridinium)-4-(4-carbamoylpyridinium) butane dibromide], show good in vitro efficacy in protecting acetylcholinesterase from inhibition by different organophosphorus compounds (OPCs), including nerve agents. To assess their efficacy in vivo, the extent of oxime-conferred protection from mortality induced by diisopropylfluorophosphate (DFP) was quantified and compared with that of five established oximes. Materials and Methods. Rats received DFP intraperitoneally in a dosage of 6, 8, or 10 micromol/rat and immediately thereafter intraperitoneal injections of K-27, K-48, pralidoxime, obidoxime, trimedoxime, methoxime, or HI-6. The relative risk (RR) of death over time (48 h) was estimated by Cox survival analysis, comparing results with the no-treatment group. Results. Best protection was observed when K-27 was used, reducing the RR of death to 19% of control RR (p < or = 0.005), whereas obidoxime (RR = 26%, p < or = 0.01), K-48 (RR = 29%, p < or = 0.005) and methoxime (RR = 26%, p < or = 0.005) were comparable. The RR of death was reduced only to about 35% of control by HI-6, to 45% by trimedoxime, and to 59% by 2-PAM (p < or = 0.005). Whereas the differences between the best oximes (K-27, obidoxime, methoxime, and K-48) were not statistically significant; these four oximes were significantly more effective than 2-PAM (p < or = 0.05). The efficacy of K-27 was also significantly higher than that of HI-6, trimedoxime, and 2-PAM (p < or = 0.05). Conclusion. Our data provide further evidence that K-27 is a very promising candidate for the treatment of intoxication with a broad spectrum of OPCs.
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Affiliation(s)
- D E Lorke
- Department of Anatomy, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE
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Myers TM, Sun W, Saxena A, Doctor BP, Bonvillain AJ, Clark MG. Systemic administration of the potential countermeasure huperzine reversibly inhibits central and peripheral acetylcholinesterase activity without adverse cognitive-behavioral effects. Pharmacol Biochem Behav 2009; 94:477-81. [PMID: 19909771 DOI: 10.1016/j.pbb.2009.10.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 10/26/2009] [Accepted: 10/30/2009] [Indexed: 11/17/2022]
Abstract
Huperzine A is potentially superior to pyridostigmine bromide as a pretreatment for nerve agent intoxication because it inhibits acetylcholinesterase both peripherally and centrally, unlike pyridostigmine, which acts only peripherally. Using rhesus monkeys, we evaluated the time course of acetylcholinesterase and butyrylcholinesterase inhibition following four different doses of -(-)huperzine A: 5, 10, 20, and 40 microg/kg. Acetylcholinesterase inhibition peaked 30 min after intramuscular injection and varied dose dependently, ranging from about 30% to 75%. Subsequently, cognitive-behavioral functioning was also evaluated at each dose of huperzine A using a six-item serial-probe recognition task that assessed attention, motivation, and working memory. Huperzine did not impair performance, but physostigmine did. The results demonstrate that huperzine A can selectively and reversibly inhibit acetylcholinesterase without cognitive-behavioral side effects, thus warranting further study.
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Affiliation(s)
- Todd M Myers
- United States Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010, USA.
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40
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Žďárová Karasová J, Bajgar J, Novotný L, Kuča K. Is a high dose of Huperzine A really suitable for pretreatment against high doses of soman? J Appl Biomed 2009. [DOI: 10.32725/jab.2009.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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41
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Harris W, Sachana M, Flaskos J, Hargreaves AJ. Neuroprotection from diazinon-induced toxicity in differentiating murine N2a neuroblastoma cells. Neurotoxicology 2009; 30:958-64. [PMID: 19596371 DOI: 10.1016/j.neuro.2009.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 05/28/2009] [Accepted: 05/28/2009] [Indexed: 12/28/2022]
Abstract
In previous work, the outgrowth of axon-like processes by differentiating mouse N2a neuroblastoma cells was shown to be inhibited by exposure to 10 microM diazinon. In the present work, N2a cells were induced to differentiate for 24 h in the presence and absence of 10 microM diazinon and 20% (v/v) conditioned medium derived from differentiating rat C6 glioma cells. Cells were then stained or lysed for morphological and biochemical analyses, respectively. The data showed that co-treatment with conditioned medium prevented the neurite inhibitory effect of diazinon. Furthermore, a significant recovery was also observed in the reduced levels of neurofilament heavy chain (NFH), heat shock protein-70 (HSP-70) and growth-associated protein-43 (GAP-43) observed as a result of diazinon treatment in the absence of conditioned medium, as seen by densitometric analysis of Western blots of cell lysates probed with monoclonal antibodies N52, BRM-22 and GAP-7B10. By contrast, no significant change was noted in the reactivity of cell lysates with antibodies against alpha- and beta-tubulin under any condition tested. After pre-incubation with a polyclonal anti-glial cell line-derived neurotrophic factor (GDNF) antibody, conditioned medium derived from rat C6 glioma cells lost its ability to protect N2a cells against the neurite inhibitory effects of diazinon. In conclusion, these data demonstrate that C6 conditioned medium protects N2a cells from the neurite inhibitory effects of diazinon by blocking molecular events leading to axon damage and that GDNF is implicated in these effects.
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Affiliation(s)
- Wayne Harris
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK
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42
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Caprio V, Ward J. Synthesis of the Bicyclo[3.3.1]nonane Core of Huperzine A and Novel Pyridine-Fused Tricycles by Cyclisation of Pyridine-Based Radicals. HETEROCYCLES 2009. [DOI: 10.3987/com-08-s(d)48] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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43
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Zou J, Wu D, Xiao D, Qi D, Liu L, Ding L, Wang G. A Sensitive LC–ESI–MS–MS Method for the Determination of Huperzine A in Human Plasma: Method and Clinical Applications. Chromatographia 2008. [DOI: 10.1365/s10337-008-0905-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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The combination of huperzine A and imidazenil is an effective strategy to prevent diisopropyl fluorophosphate toxicity in mice. Proc Natl Acad Sci U S A 2008; 105:14169-74. [PMID: 18784370 DOI: 10.1073/pnas.0807172105] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Diisopropyl fluorophosphate (DFP) causes neurotoxicity related to an irreversible inhibition of acetylcholinesterase (AChE). Management of this intoxication includes: (i) pretreatment with reversible blockers of AChE, (ii) blockade of muscarinic receptors with atropine, and (iii) facilitation of GABA(A) receptor signal transduction by benzodiazepines. The major disadvantage associated with this treatment combination is that it must to be repeated frequently and, in some cases, protractedly. Also, the use of diazepam (DZP) and congeners includes unwanted side effects, including sedation, amnesia, cardiorespiratory depression, and anticonvulsive tolerance. To avoid these treatment complications but safely protect against DFP-induced seizures and other CNS toxicity, we adopted the strategy of administering mice with (i) small doses of huperzine A (HUP), a reversible and long-lasting (half-life approximately 5 h) inhibitor of AChE, and (ii) imidazenil (IMI), a potent positive allosteric modulator of GABA action selective for alpha(5)-containing GABA(A) receptors. Coadministration of HUP (50 microg/kg s.c., 15 min before DFP) with IMI (2 mg/kg s.c., 30 min before DFP) prevents DFP-induced convulsions and the associated neuronal damage and mortality, allowing complete recovery within 18-24 h. In HUP-pretreated mice, the ED(50) of IMI to block DFP-induced mortality is approximately 10 times lower than that of DZP and is devoid of sedation. Our data show that a combination of HUP with IMI is a prophylactic, potent, and safe therapeutic strategy to overcome DFP toxicity.
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Protection of red blood cell acetylcholinesterase by oral huperzine A against ex vivo soman exposure: Next generation prophylaxis and sequestering of acetylcholinesterase over butyrylcholinesterase. Chem Biol Interact 2008; 175:380-6. [DOI: 10.1016/j.cbi.2008.04.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Revised: 04/22/2008] [Accepted: 04/23/2008] [Indexed: 11/18/2022]
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46
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Lorke D, Hasan M, Nurulain S, Shafiullah M, Nagelkerke N, Petroianu G. Effect of intrathecal pralidoxime administration upon survival of rats exposed to the organophosphate paraoxon. Neurotoxicology 2008; 29:663-70. [DOI: 10.1016/j.neuro.2008.03.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 12/04/2007] [Accepted: 03/14/2008] [Indexed: 11/29/2022]
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47
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Bajgar J. Protective effect of reversible cholinesterase inhibitors (tacrine, pyridostigmine) and eqbuche against VX poisoning and brain acetylcholinesterase inhibition in rats. ACTA MEDICA (HRADEC KRALOVE) 2008; 51:223-228. [PMID: 19453088 DOI: 10.14712/18059694.2017.28] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The protective effect of the reversible cholinesterase inhibitors tacrine and pyridostigmine alone or in combination with different drugs against acetylcholinesterase inhibition in the pontomedullar area and cerebellum of rats caused by VX agent (O-ethyl S-2-diisopropylaminoethyl methyl phosphonothiolate) in vivo (2xLD50) was studied along with survival of animals pretreated with different combinations of the drugs used. The best prophylactic effect was observed in a combination of pyridostigmine with benactyzine, trihexyphenidyle and HI-6. Tacrine alone or in other combinations has had no better prophylactic effect in comparison with these combinations containing pyridostigmine. Equine butyrylcholinesterase, also protected against VX poisoning very effectively.
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Affiliation(s)
- Jirí Bajgar
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology, Hradec Králové, Czech Republic.
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48
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Inhibition of Acetylcholinesterase in Different Structures of the Rat Brain Following Soman Intoxication Pretreated with Huperzine A. Int J Mol Sci 2007. [DOI: 10.3390/i8111165] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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49
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Lorke DE, Hasan MY, Nurulain SM, Sheen R, Kuca K, Petroianu GA. Entry of two new asymmetric bispyridinium oximes (K-27 and K-48) into the rat brain: comparison with obidoxime. J Appl Toxicol 2007; 27:482-90. [PMID: 17309042 DOI: 10.1002/jat.1229] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the search for new oximes with higher reactivation potency and a broader spectrum, K-27 and K-48, have recently been synthesized. To test if their superior efficacy was related to better penetration across the blood-brain barrier, their brain entry was compared with that of obidoxime, when administered either alone or after the organophosphate paraoxon (POX). Rats received 50 micromol obidoxime, K-27 or K-48, either alone or in addition to 1 micromol POX. Oxime concentrations at various points in time in brain and plasma were measured using HPLC. The obidoxime C(max) in brain was 1.3% of the plasma C(max) when injected alone, and 1.5% when injected following POX. The ratio of the area under the curve (AUC) brain to plasma for obidoxime was around 6%, irrespective of whether it was administered alone or after POX. For K-27, C(max) (brain) was 0.6% of C(max) (plasma) when injected alone, and 0.7% when injected after POX (no significant difference). The AUC (brain) was 2% of AUC (plasma) for both K-27 groups. K-48, when injected alone reached 1.4% of C(max) (plasma) in the brain and 1.2% of C(max) (plasma), when injected following POX. The AUC (brain) was 5% of the AUC (plasma), both when K-48 was administered alone and in combination with POX. Entry of all three oximes into the brain is minimal and cannot explain the better therapeutic efficacy of K-27 and K-48. As already observed for pralidoxime, injection of POX before oxime administration had no influence upon penetration across the blood-brain barrier.
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Affiliation(s)
- D E Lorke
- Department of Anatomy, FMHS, UAE University, Al Ain, United Arab Emirates
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50
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Ma X, Tan C, Zhu D, Gang DR, Xiao P. Huperzine A from Huperzia species--an ethnopharmacolgical review. JOURNAL OF ETHNOPHARMACOLOGY 2007; 113:15-34. [PMID: 17644292 DOI: 10.1016/j.jep.2007.05.030] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Revised: 05/28/2007] [Accepted: 05/30/2007] [Indexed: 05/16/2023]
Abstract
Huperzine A (HupA), isolated originally from a traditional Chinese medicine Qiang Ceng Ta, whole plant of Huperzia serrata (Thunb. ex Murray) Trev., a member of the Huperziaceae family, has attracted intense attention since its marked anticholinesterase activity was discovered by Chinese scientists. Several members of the Huperziaceae (Huperzia and Phlegmariurus species) have been used as medicines in China for contusions, strains, swellings, schizophrenia, myasthenia gravis and organophosphate poisoning. HupA has been marketed in China as a new drug for Alzheimer's disease (AD) treatment and its derivative ZT-1 is being developed as anti-AD new drug candidate both in China and in Europe. A review of the chemistry, bioactivities, toxicology, clinical trials and natural resources of HupA source plants is presented.
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Affiliation(s)
- Xiaoqiang Ma
- State Key Laboratory of Drug Research, Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, PR China
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