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Sun X, Jia X, Lu Z, Tang J, Li M. Drug repositioning with adaptive graph convolutional networks. Bioinformatics 2024; 40:btad748. [PMID: 38070161 PMCID: PMC10761094 DOI: 10.1093/bioinformatics/btad748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 11/27/2023] [Accepted: 12/08/2023] [Indexed: 01/04/2024] Open
Abstract
MOTIVATION Drug repositioning is an effective strategy to identify new indications for existing drugs, providing the quickest possible transition from bench to bedside. With the rapid development of deep learning, graph convolutional networks (GCNs) have been widely adopted for drug repositioning tasks. However, prior GCNs based methods exist limitations in deeply integrating node features and topological structures, which may hinder the capability of GCNs. RESULTS In this study, we propose an adaptive GCNs approach, termed AdaDR, for drug repositioning by deeply integrating node features and topological structures. Distinct from conventional graph convolution networks, AdaDR models interactive information between them with adaptive graph convolution operation, which enhances the expression of model. Concretely, AdaDR simultaneously extracts embeddings from node features and topological structures and then uses the attention mechanism to learn adaptive importance weights of the embeddings. Experimental results show that AdaDR achieves better performance than multiple baselines for drug repositioning. Moreover, in the case study, exploratory analyses are offered for finding novel drug-disease associations. AVAILABILITY AND IMPLEMENTATION The soure code of AdaDR is available at: https://github.com/xinliangSun/AdaDR.
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Affiliation(s)
- Xinliang Sun
- School of Computer Science and Engineering, Central South University, Changsha, Hunan 410083, China
| | - Xiao Jia
- School of Computer Science and Engineering, Central South University, Changsha, Hunan 410083, China
| | - Zhangli Lu
- School of Computer Science and Engineering, Central South University, Changsha, Hunan 410083, China
| | - Jing Tang
- Research Program in Systems Oncology, Faculty of Medicine, University of Helsinki, FI00014 Helsinki, Finland
| | - Min Li
- School of Computer Science and Engineering, Central South University, Changsha, Hunan 410083, China
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Kassa J, Zdarova Karasova J. Combination of acetylcholinesterase inhibitors and NMDA receptor antagonists increases survival rate in soman-poisoned mice. Toxicol Mech Methods 2023; 33:590-595. [PMID: 37051629 DOI: 10.1080/15376516.2023.2202730] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/19/2023] [Accepted: 04/08/2023] [Indexed: 04/14/2023]
Abstract
Organophosphorus nerve agents pose a global threat to both military personnel and civilian population, because of their high acute toxicity and insufficient medical countermeasures. Commonly used drugs could ameliorate the intoxication and overall medical outcomes. In this study, we tested the drugs able to alleviate the symptoms of Alzheimer's disease (donepezil, huperzine A, memantine) or Parkinson's disease (procyclidine). They were administered to mice before soman intoxication in terms of their: i) protection potential against soman toxicity and ii) influence on post-exposure therapy consisting of atropine and asoxime (also known as oxime HI-6). Their pretreatment effect was not significant, when administered alone, but in combination (acetylcholinesterase inhibitor such as denepezil or huperzine A with NMDA antagonist such as memantine or procyclidine) they lowered the soman toxicity more than twice. These combinations also positively influenced the efficacy of post-exposure treatment in a similar fashion; the combinations increased the therapeutic effectiveness of antidotal treatment. In conclusion, the most effective combination - huperzine A and procyclidine - lowered the toxicity three times and improved the post-exposure therapy efficacy more than six times. These results are unprecedented in the published literature.
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Affiliation(s)
- Jiri Kassa
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Jana Zdarova Karasova
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
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3
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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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Abd El-Aziz NM, Shehata MG, Alsulami T, Badr AN, Elbakatoshy MR, Ali HS, El-Sohaimy SA. Characterization of Orange Peel Extract and Its Potential Protective Effect against Aluminum Chloride-Induced Alzheimer's Disease. Pharmaceuticals (Basel) 2022; 16:ph16010012. [PMID: 36678510 PMCID: PMC9864618 DOI: 10.3390/ph16010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/09/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder without a cure. Hence, developing an effective treatment or protective agent is crucial for public health. The present study aims to characterize orange peel extract (OPE) through in vitro and in silico studies. Furthermore, it examines the protective effect of OPE against experimentally-induced Alzheimer's disease in rats. The total phenolic and flavonoid content of OPE was 255.86 ± 1.77 and 52.06 ± 1.74 (mg/100 g), respectively. Gallic acid, the common polyphenol in OPE detected by HPLC was 3388.60 μg/100 g. OPE antioxidant IC50 was 67.90 ± 1.05, 60.48 ± 0.91, and 63.70 ± 0.30 by DPPH, ABTS and Hydroxyl radical scavenging activity methods, respectively. In vitro anti-acetylcholinesterase (AChE) IC50 was 0.87 ± 0.025 mg/mL for OPE and 2.45 ± 0.001 mg/mL for gallic acid. Molecular docking analysis for human AChE (4EY7) with donepezil, gallic acid, and acetylcholine showed binding energy ΔG values of -9.47, -3.72, and -5.69 Kcal/mol, respectively. Aluminum chloride injection (70 mg/Kg/day for 6 weeks) induced Alzheimer's-like disease in male rats. OPE (100 and 200 mg/kg/d) and gallic acid (50 mg/kg/d) were administered orally to experimental animals for 6 weeks in addition to aluminum chloride injection (as protective). OPE was found to protect against aluminum chloride-induced neuronal damage by decreasing both gene expression and activity of acetylcholinesterase (AChE) and a decrease in amyloid beta (Aβ42) protein level, thiobarbituric acid-reactive substances (TBARS), and nitric oxide (NO), and increased reduced glutathione (GSH) level and activity of the antioxidant enzymes in the brain tissues. Additionally, gene expressions for amyloid precursor protein (APP) and beta secretase enzyme (BACE1) were downregulated, whereas those for presinilin-2 (PSEN2) and beta cell lymphoma-2 (BCL2) were upregulated. Furthermore, the reverse of mitochondrial alternation and restored brain ultrastructure might underlie neuronal dysfunction in AD. In conclusion, our exploration of the neuroprotective effect of OPE in vivo reveals that OPE may be helpful in ameliorating brain oxidative stress, hence protecting from Alzheimer's disease progression.
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Affiliation(s)
- Nourhan Mohammad Abd El-Aziz
- Department of Food Technology, Arid Lands Cultivation Research Institute (ALCRI), City of Scientific Research and Technological Applications (SRTA-City), Alexandria 21934, Egypt
- Correspondence:
| | - Mohamed Gamal Shehata
- Department of Food Technology, Arid Lands Cultivation Research Institute (ALCRI), City of Scientific Research and Technological Applications (SRTA-City), Alexandria 21934, Egypt
- Food Research Section, R&D Division, Abu Dhabi Agriculture and Food Safety Authority (ADAFSA), Abu Dhabi P.O. Box 52150, United Arab Emirates
| | - Tawfiq Alsulami
- Department of Food Science & Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia
| | - Ahmed Noah Badr
- Food Toxicology and Contaminants Department, National Research Centre, Dokki, Cairo 12622, Egypt
| | - Marwa Ramadan Elbakatoshy
- Department of Food Technology, Arid Lands Cultivation Research Institute (ALCRI), City of Scientific Research and Technological Applications (SRTA-City), Alexandria 21934, Egypt
| | - Hatem Salama Ali
- Food Science Department, National Research Centre, Dokki, Cairo 12622, Egypt
| | - Sobhy Ahmed El-Sohaimy
- Department of Food Technology, Arid Lands Cultivation Research Institute (ALCRI), City of Scientific Research and Technological Applications (SRTA-City), Alexandria 21934, Egypt
- Department of Technology and Organization of Public Catering, Institute of Sport, Tourism and Service, South Ural State University (SUSU), 454080 Chelyabinsk, Russia
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The effect of combination pretreatment of donepezil and environmental enrichment on memory deficits in amyloid-beta-induced Alzheimer-like rat model. Biochem Biophys Rep 2022; 32:101392. [DOI: 10.1016/j.bbrep.2022.101392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/07/2022] [Accepted: 11/15/2022] [Indexed: 11/25/2022] Open
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Lushchekina SV, Masson P. Slow-binding inhibitors of acetylcholinesterase of medical interest. Neuropharmacology 2020; 177:108236. [PMID: 32712274 DOI: 10.1016/j.neuropharm.2020.108236] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 06/11/2020] [Accepted: 07/10/2020] [Indexed: 12/15/2022]
Abstract
Certain ligands slowly bind to acetylcholinesterase. As a result, there is a slow establishment of enzyme-inhibitor equilibrium characterized by a slow onset of inhibition prior reaching steady state. Three mechanisms account for slow-binding inhibition: a) slow binding rate constant kon, b) slow ligand induced-fit following a fast binding step, c) slow conformational selection of an enzyme form. The slow equilibrium may be followed by a chemical step. This later that can be irreversible has been observed with certain alkylating agents and substrate transition state analogs. Slow-binding inhibitors present long residence times on target. This results in prolonged pharmacological or toxicological action. Through several well-known molecules (e.g. huperzine) and new examples (tocopherol, trifluoroacetophenone and a 6-methyluracil alkylammonium derivative), we show that slow-binding inhibitors of acetylcholinesterase are promising drugs for treatment of neurological diseases such as Alzheimer disease and myasthenia gravis. Moreover, they may be of interest for neuroprotection (prophylaxis) against organophosphorus poisoning. This article is part of the special issue entitled 'Acetylcholinesterase Inhibitors: From Bench to Bedside to Battlefield'.
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Affiliation(s)
- Sofya V Lushchekina
- Laboratory of Computer Modeling of Biomolecular Systems and Nanomaterials, Emanuel Institute of Biochemical Physics of RAS, 4 Kosygina St., Moscow, 119334, Russia.
| | - Patrick Masson
- Laboratory of Neuropharmacology, Kazan Federal University, 18 Kremlyovskaya St., Kazan, 420008, Russia.
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Silkis IG. Role of Acetylcholine and GABAergic Inhibitory Transmission in Seizure Pattern Generation in Neural Networks Integrating the Neocortex, Hippocampus, Basal Ganglia, and Thalamus. NEUROCHEM J+ 2020. [DOI: 10.1134/s1819712420020129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Werner FM, Coveñas R. Neural Networks in Generalized Epilepsy and Novel Antiepileptic Drugs. Curr Pharm Des 2020; 25:396-400. [PMID: 30892153 DOI: 10.2174/1381612825666190319121505] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 03/13/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND In previous works, alterations of neurotransmitters and neuropeptides in the brain areas involved in generalized epilepsy have been reported. OBJECTIVE We reviewed the alterations of these neurotransmitters and neuropeptides in the following brain areas involved in generalized epilepsy: hippocampus, hypothalamus, thalamus and cerebral cortex. In these brain areas, the neural networks are also actualized. The mechanisms of action of newer antiepileptic drugs in the treatment of generalized epilepsy are also discussed. RESULTS Up-dating the neurotransmitter and neuropeptide alterations, we found that hippocampal GABAergic neurons presynaptically inhibit epileptogenic neurons via GABAB receptors. Epilepsy modulating neuropeptides (galanin, neuropeptide Y, dynorphin) are also involved. GABA deficiency, serotonin hyperactivity, dopamine hyperactivity and glutamate excitotoxicity can enhance ictogenesis: neurons containing these neurotransmitters form the main neural circuit. An increased excitability occurs when the alteration of these neurotransmitters is permanent. CONCLUSION In preclinical studies, the GABAB receptor agonist GS 39,783 exerted a good antiepileptic effect. Perampanel, an AMPA receptor antagonist, showed good clinical effects in the treatment of partial-onset seizures and primary generalized tonic-clonic seizures. In this treatment, perampanel can be combined with other antiepileptic drugs. Brivaracetam, which shows a high affinity for the synaptic vesicle 2A, exerted a good efficacy in the treatment of adult focal seizures and secondarily generalized tonic-clonic seizures.
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Affiliation(s)
- Felix-Martin Werner
- Höhere Berufsfachschule für Altenpflege und Ergotherapie der Euro Akademie, Pößneck, Pößneck, Germany.,Institute of Neurosciences of Castilla y Leon (INCYL), Laboratory of Neuroanatomy of the Peptidergic Systems, University of Salamanca, Salamanca, Spain
| | - Rafael Coveñas
- Institute of Neurosciences of Castilla y Leon (INCYL), Laboratory of Neuroanatomy of the Peptidergic Systems, University of Salamanca, Salamanca, Spain
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Wong JC, Thelin JT, Escayg A. Donepezil increases resistance to induced seizures in a mouse model of Dravet syndrome. Ann Clin Transl Neurol 2019; 6:1566-1571. [PMID: 31402621 PMCID: PMC6689688 DOI: 10.1002/acn3.50848] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 06/27/2019] [Accepted: 06/28/2019] [Indexed: 01/11/2023] Open
Abstract
De novo loss-of-function mutations in SCN1A are the main cause of Dravet syndrome, a catastrophic encephalopathy characterized by recurrent early-life febrile seizures, a number of other afebrile seizure types that are often refractory to treatment, and behavioral abnormalities including social deficits, motor dysfunction, and cognitive impairment. We previously demonstrated that the reversible acetylcholinesterase inhibitor, Huperzine A, increases seizure resistance in Scn1a mutants. In the present study, we evaluated the therapeutic potential of donepezil, a reversible acetylcholinesterase inhibitor approved by the Food and Drug Administration, in a mouse model of Dravet syndrome (Scn1a+/- ). We found that donepezil conferred robust protection against induced seizures in Scn1a+/- mutants.
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Affiliation(s)
- Jennifer C Wong
- Department of Human Genetics, Emory University, Atlanta, GA, 30322
| | | | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, GA, 30322
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10
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Werner FM, Coveñas R. Classical neurotransmitters and neuropeptides involved in generalized epilepsy in a multi-neurotransmitter system: How to improve the antiepileptic effect? Epilepsy Behav 2017; 71:124-129. [PMID: 25819950 DOI: 10.1016/j.yebeh.2015.01.038] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Revised: 01/27/2015] [Accepted: 01/28/2015] [Indexed: 12/20/2022]
Abstract
Here, we describe in generalized epilepsies the alterations of classical neurotransmitters and neuropeptides acting at specific subreceptors. In order to consider a network context rather than one based on focal substrates and in order to make the interaction between neurotransmitters and neuropeptides and their specific subreceptors comprehensible, neural networks in the hippocampus, thalamus, and cerebral cortex are described. In this disease, a neurotransmitter imbalance between dopaminergic and serotonergic neurons and between presynaptic GABAergic neurons (hypoactivity) and glutaminergic neurons (hyperactivity) occurs. Consequently, combined GABAA agonists and NMDA antagonists could furthermore stabilize the neural networks in a multimodal pharmacotherapy. The antiepileptic effect and the mechanisms of action of conventional and recently developed antiepileptic drugs are reviewed. The GASH:Sal animal model can contribute to examine the efficacy of antiepileptic drugs. The issues of whether the interaction of classical neurotransmitters with other subreceptors (5-HT7, metabotropic 5 glutaminergic, A2A adenosine, and alpha nicotinic 7 cholinergic receptors) or whether the administration of agonists/antagonists of neuropeptides might improve the therapeutic effect of antiepileptic drugs should be addressed. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic".
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Affiliation(s)
- Felix-Martin Werner
- Höhere Berufsfachschule für Altenpflege und Ergotherapie der Euro Akademie Pößneck, Pößneck, Germany; Institute of Neurosciences of Castilla y León (INCYL), Laboratory of Neuroanatomy of the Peptidergic Systems (Lab. 14), University of Salamanca, Salamanca, Spain.
| | - Rafael Coveñas
- Institute of Neurosciences of Castilla y León (INCYL), Laboratory of Neuroanatomy of the Peptidergic Systems (Lab. 14), University of Salamanca, Salamanca, Spain.
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Myhrer T, Aas P. Pretreatment and prophylaxis against nerve agent poisoning: Are undesirable behavioral side effects unavoidable? Neurosci Biobehav Rev 2016; 71:657-670. [PMID: 27773692 DOI: 10.1016/j.neubiorev.2016.10.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 09/28/2016] [Accepted: 10/19/2016] [Indexed: 10/20/2022]
Abstract
The threat of chemical warfare agents like nerve agents requires life saving measures of medical pretreatment combined with treatment after exposure. Pretreatment (pyridostigmine) may cause some side effects in a small number of individuals. A comprehensive research on animals has been performed to clarify effects on behavior. The results from these studies are far from unambiguous, since pyridostigmine may produce adverse effects on behavior in animals in relatively high doses, but not in a consistent way. Other animal studies have examined the potential of drugs like physostigmine, galantamine, benactyzine, trihexyphenidyl, and procyclidine, but they all produce marked behavioral impairment at doses sufficient to contribute to protection against a convulsant dose of soman. Attempts have also been made to develop a combination of drugs capable of assuring full protection (prophylaxis) against nerve agents. However, common to all combinations is that they at anticonvulsant doses cause behavioral deficits. Therefore, the use of limited pretreatment doses may be performed without marked side effects followed by post-exposure therapy with a combination of drugs.
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Affiliation(s)
- Trond Myhrer
- Norwegian Defence Research Establishment (FFI), Protection and Societal Security Division, Kjeller, Norway
| | - Pål Aas
- Norwegian Defence Research Establishment (FFI), Protection and Societal Security Division, Kjeller, Norway.
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Lavon O, Eisenkraft A, Blanca M, Raveh L, Ramaty E, Krivoy A, Atsmon J, Grauer E, Brandeis R. Is rivastigmine safe as pretreatment against nerve agents poisoning? A pharmacological, physiological and cognitive assessment in healthy young adult volunteers. Neurotoxicology 2015; 49:36-44. [DOI: 10.1016/j.neuro.2015.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 05/04/2015] [Accepted: 05/11/2015] [Indexed: 01/02/2023]
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Choice of approaches in developing novel medical countermeasures for nerve agent poisoning. Neurotoxicology 2014; 44:27-38. [DOI: 10.1016/j.neuro.2014.04.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 03/24/2014] [Accepted: 04/30/2014] [Indexed: 11/24/2022]
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de Araujo Furtado M, Rossetti F, Chanda S, Yourick D. Exposure to nerve agents: from status epilepticus to neuroinflammation, brain damage, neurogenesis and epilepsy. Neurotoxicology 2012; 33:1476-1490. [PMID: 23000013 DOI: 10.1016/j.neuro.2012.09.001] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Revised: 07/25/2012] [Accepted: 09/03/2012] [Indexed: 12/17/2022]
Abstract
Epilepsy is a common neurological disorder characterized by an initial injury due to stroke, traumatic brain injury, brain infection, or febrile seizures causing status epilepticus (SE). This phenomenon precedes recurrent (secondary) seizures, the latent period (period without seizures) and downstream appearance of spontaneous recurrent seizures (SRS). Epilepsy inducers include the organophosphorous (OP) compounds modified as chemical warfare nerve agents, such as soman. SE induced by soman is a result of cholinergic system hyperactivity caused by the irreversible inhibition of acetylcholinesterase, and the subsequent increase in the amount of the neurotransmitter acetylcholine at central and peripheral sites. SE leads to profound, permanent, complex and widespread brain damage and associated cognitive and behavioral deficits, accompanied by impaired neurogenesis. Several anticonvulsant and neuroprotective strategies have been studied in order to avoid the epileptogenesis which occurs after SE caused by soman exposure. In recent studies, we showed that SRS occur post-soman exposure and neuropathology can be reduced with diazepam (DZP) and valproic acid (VPA) when administered in combination treatment. These effects are accompanied by neurogenesis seen 15 days post-exposure in the hippocampal dentate gyrus (DG). This review discusses several findings about epilepsy induced by soman exposure such as behavioral changes, EEG anomalies, neuropathology, neuroinflammation, neurogenesis, possible circuitry changes and current strategies for treatment. The soman seizure model is an important model of temporal lobe epilepsy (TLE) and comparable in certain respects with well studied models in the literature such as pilocarpine and kainic acid. All these models together allow for a greater understanding of the different mechanisms of seizure induction, propagation and options for treatment. These studies are very necessary for current military and civilian treatment regimens, against OP nerve agent exposure, which fail to prevent SE resulting in severe neuropathology and epilepsy.
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Affiliation(s)
- Marcio de Araujo Furtado
- Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Franco Rossetti
- Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Soma Chanda
- Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Debra Yourick
- Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States.
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Cho Y, Kim WS, Hur GH, Ha YC. Minimum effective drug concentrations of a transdermal patch system containing procyclidine and physostigmine for prophylaxis against soman poisoning in rhesus monkeys. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2012; 33:1-8. [PMID: 22051905 DOI: 10.1016/j.etap.2011.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 08/25/2011] [Accepted: 10/07/2011] [Indexed: 05/31/2023]
Abstract
A transdermal patch system containing procyclidine, an N-methyl-d-aspartate receptor antagonist possessing anticholinergic action, and physostigmine, a reversible cholinesterase inhibitor, was developed, and its prophylactic efficacy against soman intoxication was investigated. Male rhesus monkeys were shaved on the dorsal area, attached with a matrix-type patch with various sizes (2×2 to 7×7 cm) for 24 or 72 h, and challenged with 2×LD₅₀ doses (13μg/kg) of soman. The smallest patch size for the protection against lethality induced by soman intoxication was 3×3cm, resulting in blood procyclidine concentration of 10.8 ng/ml, blood physostigmine concentration of 0.54 ng/ml, which are much lower concentrations than maximum sign-free doses, and blood cholinesterase inhibition of 42%. The drug concentrations and enzyme inhibition rate corresponding to a diverging point of survivability were presumably estimated to be around 7 ng/ml for procyclidine, 0.35 ng/ml for physostigmine, and 37% of enzyme inhibition. Separately, in combination with the patch treatment, the post treatment consisting of atropine (0.5 mg/kg) plus 1-[([4-(aminocarbonyl)pyridinio]methoxy)methyl]-2-[(hydroxyimino)methyl]pyridinium (HI-6, 50 mg/kg) exerted protection against 5×LD₅₀ challenge of soman, which means the posttreatment remarkably augmented the efficacy of the patch. Additionally, it was found that brain injuries induced by soman toxicity were effectively prevented by the patch treatment according to histopathological examinations. These results suggest that the patch system could be an effective alternative for diazepam, an anticonvulsant, and the current pyridostigmine pretreatment, and especially in combination with atropine plus HI-6, could be a choice for quality survival from nerve-agent poisoning.
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Affiliation(s)
- Young Cho
- Chemical Biological Defense Research Division, 5th R&D Center (5-4), Agency for Defense Development, Yuseong P.O. Box 35, Taejon 305-600, Republic of Korea.
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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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17
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Aracava Y, Pereira EFR, Akkerman M, Adler M, Albuquerque EX. Effectiveness of donepezil, rivastigmine, and (+/-)huperzine A in counteracting the acute toxicity of organophosphorus nerve agents: comparison with galantamine. J Pharmacol Exp Ther 2009; 331:1014-24. [PMID: 19741148 DOI: 10.1124/jpet.109.160028] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Galantamine, a centrally acting cholinesterase (ChE) inhibitor and a nicotinic allosteric potentiating ligand used to treat Alzheimer's disease, is an effective and safe antidote against poisoning with nerve agents, including soman. Here, the effectiveness of galantamine was compared with that of the centrally active ChE inhibitors donepezil, rivastigmine, and (+/-)huperzine A as a pre- and/or post-treatment to counteract the acute toxicity of soman. In the first set of experiments, male prepubertal guinea pigs were treated intramuscularly with one of the test drugs and 30 min later challenged with 1.5 x LD(50) soman (42 microg/kg s.c.). All animals that were pretreated with galantamine (6-8 mg/kg), 3 mg/kg donepezil, 6 mg/kg rivastigmine, or 0.3 mg/kg (+/-)huperzine A survived the soman challenge, provided that they were also post-treated with atropine (10 mg/kg i.m.). However, only galantamine was well tolerated. In subsequent experiments, the effectiveness of specific treatment regimens using 8 mg/kg galantamine, 3 mg/kg donepezil, 6 mg/kg rivastigmine, or 0.3 mg/kg (+/-)huperzine A was compared in guinea pigs challenged with soman. In the absence of atropine, only galantamine worked as an effective and safe pretreatment in animals challenged with 1.0 x LD(50) soman. Galantamine was also the only drug to afford significant protection when given to guinea pigs after 1.0 x LD(50) soman. Finally, all test drugs except galantamine reduced the survival of the animals when administered 1 or 3 h after the challenge with 0.6 or 0.7 x LD(50) soman. Thus, galantamine emerges as a superior antidotal therapy against the toxicity of soman.
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Affiliation(s)
- Yasco Aracava
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Weissman BA, Raveh L. Therapy against organophosphate poisoning: The importance of anticholinergic drugs with antiglutamatergic properties. Toxicol Appl Pharmacol 2008; 232:351-8. [DOI: 10.1016/j.taap.2008.07.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Revised: 06/23/2008] [Accepted: 07/07/2008] [Indexed: 10/21/2022]
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Chaudhry FA, Edwards RH, Fonnum F. Vesicular neurotransmitter transporters as targets for endogenous and exogenous toxic substances. Annu Rev Pharmacol Toxicol 2008; 48:277-301. [PMID: 17883368 DOI: 10.1146/annurev.pharmtox.46.120604.141146] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Exocytotic release of neurotransmitters requires their accumulation inside preformed secretory vesicles. Distinct vesicular transport activities translocate classical transmitters into synaptic vesicles energized by a H+ electrochemical gradient (Delta(mu(H+))), with subtle but important differences in dependence on the electrical and chemical components. The vesicular transporters also interact with toxic compounds and drugs. They mediate neuroprotection by sequestering toxic compounds as well as neurotransmitters into vesicles, reducing their concentration in the cytosol where they may have detrimental effects. Both therapeutic agents and psychostimulants interfering with vesicular transport have yielded insight into the pathogenesis of psychiatric as well as neurodegenerative diseases. Thus, specific inhibitors have helped to characterize both the physiological role and mechanism of vesicular neurotransmitter transport.
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Affiliation(s)
- Farrukh A Chaudhry
- Centre for Molecular Biology and Neuroscience, The Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway.
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Myhrer T. Neuronal structures involved in the induction and propagation of seizures caused by nerve agents: Implications for medical treatment. Toxicology 2007; 239:1-14. [PMID: 17689166 DOI: 10.1016/j.tox.2007.06.099] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Revised: 06/15/2007] [Accepted: 06/18/2007] [Indexed: 11/30/2022]
Abstract
In epilepsy research, studies have been made to identify brain areas critical for triggering and/or controlling propagated seizure activity. The purpose of the present study was to focus on a similar approach in nerve agent research by reviewing relevant literature to map potential trigger sites and propagation pathways for seizures. The piriform cortex and medial septal area emerge as prime target areas for soman-induced seizures. The cholinergic hyperactivation in the latter structures seems to induce increased glutamatergic activity in the piriform, entorhinal, and perirhinal cortices along with the hippocampal region. For prophylactic or early treatment, mapping of muscarinic subreceptors in the piriform cortex and medial septum would be guiding for designing anticholinergic drugs with optimal properties. Sustained seizures governed by glutamatergic over-activity may primarily be terminated by drugs with optimal glutamatergic antagonism primarily in the piriform, entorhinal, and perirhinal cortices. Studies of radiolabeled ligands to map subreceptors may provide specification of wanted drug properties to guide the choice among existing agents or to synthesize novel ones.
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Affiliation(s)
- Trond Myhrer
- Norwegian Defence Research Establishment, Protection Division, NO-2027, Kjeller, Norway.
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