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Wu PP, Cao BR, Tian FY, Gao ZB. Development of SV2A Ligands for Epilepsy Treatment: A Review of Levetiracetam, Brivaracetam, and Padsevonil. Neurosci Bull 2024; 40:594-608. [PMID: 37897555 PMCID: PMC11127901 DOI: 10.1007/s12264-023-01138-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 08/16/2023] [Indexed: 10/30/2023] Open
Abstract
Epilepsy is a common neurological disorder that is primarily treated with antiseizure medications (ASMs). Although dozens of ASMs are available in the clinic, approximately 30% of epileptic patients have medically refractory seizures; other limitations in most traditional ASMs include poor tolerability and drug-drug interactions. Therefore, there is an urgent need to develop alternative ASMs. Levetiracetam (LEV) is a first-line ASM that is well tolerated, has promising efficacy, and has little drug-drug interaction. Although it is widely accepted that LEV acts through a unique therapeutic target synaptic vesicle protein (SV) 2A, the molecular basis of its action remains unknown. Even so, the next-generation SV2A ligands against epilepsy based on the structure of LEV have achieved clinical success. This review highlights the research and development (R&D) process of LEV and its analogs, brivaracetam and padsevonil, to provide ideas and experience for the R&D of novel ASMs.
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Affiliation(s)
- Peng-Peng Wu
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bi-Rong Cao
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fu-Yun Tian
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhongshan, 528400, China.
| | - Zhao-Bing Gao
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhongshan, 528400, China.
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Mohs R, Bakker A, Rosenzweig‐Lipson S, Rosenblum M, Barton RL, Albert MS, Cohen S, Zeger S, Gallagher M. The HOPE4MCI study: A randomized double-blind assessment of AGB101 for the treatment of MCI due to AD. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2024; 10:e12446. [PMID: 38356475 PMCID: PMC10865488 DOI: 10.1002/trc2.12446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 10/25/2023] [Accepted: 12/27/2023] [Indexed: 02/16/2024]
Abstract
INTRODUCTION In addition to the accumulation of amyloid plaques and neurofibrillary tangles, the presence of excess neural activity is a pathological hallmark of Alzheimer's disease (AD) and a prognostic indicator for progression of AD pathology and clinical/cognitive worsening in mild cognitive impairment due to Alzheimer's disease (MCI due to AD). The HOPE4MCI clinical study tested the efficacy of a therapeutic with demonstrated ability to normalize heightened neural activity in the hippocampus in a randomized controlled trial of 78 weeks duration in patients with MCI due to AD. METHODS One hundred and sixty-four participants were randomized to placebo (n = 83) or AGB101 (n = 81), an extended-release formulation of low dose (220 mg) levetiracetam. The primary endpoint was the change in Clinical Dementia Rating Scale Sum of Boxes score (CDR-SB) comparing follow up at 18 months to baseline. The goal of the primary efficacy analysis was to estimate the difference between the AGB101 and placebo arms in the mean change of the primary endpoint. RESULTS The mean change in CDR-SB was estimated to be 1.12 (95% confidence interval [CI]: 0.66, 1.69) for the AGB101 arm and 1.22 (95% CI: 0.75, 1.78) for the placebo arm. The estimated difference between arms is -0.10 (95% CI: -0.85, 0.58), which was not statistically significant. In a prespecified analysis, the difference was -0.45 (95% CI: -1.43, 0.53) for ApoE-4 noncarriers and -0.10 (95% CI: -0.92, 0.72) for apolipoprotein E (ApoE)-4 carriers. DISCUSSION The possibility that ApoE-4 carriers and noncarriers will respond differently to therapeutic intervention is consistent with recently reported findings from biologics and the present results show further testing of AGB101 in patients with MCI due to AD who are noncarriers of the ApoeE-4 allele is warranted. Conclusions from the HOPE4MCI study are limited primarily due to the small sample size and results can only be regarded as a guide to future research.
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Affiliation(s)
| | - Arnold Bakker
- Department of Psychiatry and Behavioral SciencesJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Department of NeurologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Department of Psychological and Brain SciencesJohns Hopkins UniversityBaltimoreMarylandUSA
| | | | - Michael Rosenblum
- Department of BiostatisticsJohns Hopkins University Bloomberg School of Public HealthBaltimoreMarylandUSA
| | | | - Marilyn S. Albert
- Department of NeurologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | | | - Scott Zeger
- Department of BiostatisticsJohns Hopkins University Bloomberg School of Public HealthBaltimoreMarylandUSA
| | - Michela Gallagher
- AgeneBio, Inc.BaltimoreMarylandUSA
- Department of Psychological and Brain SciencesJohns Hopkins UniversityBaltimoreMarylandUSA
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JAMAL M, AZAM M, KHAN SA, UL-HAQ Z, SIMJEE SU. Levetiracetam ameliorates epileptogenesis by modulating the adenosinergic pathway in a kindling model of epilepsy in mice. Turk J Med Sci 2023; 53:1045-1057. [PMID: 38813043 PMCID: PMC10763745 DOI: 10.55730/1300-0144.5669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 10/26/2023] [Accepted: 03/07/2023] [Indexed: 05/31/2024] Open
Abstract
Background Levetiracetam (LEV) has been found to have an antihyperalgesic effect via acting on the adenosine system. However, the effects of LEV on the modulation of the adenosine system in the brain have not been elucidated in the prevention of seizures and epilepsy. The present study aimed to explore the possible LEV mechanisms of action in the adenosine signaling systems in an animal model of epilepsy. Methodology A docking study was initially performed to determine the possible interaction of LEV with adenosine A1 receptors (A1Rs) and equilibrative nucleoside transporters-1 (ENT1). The experimental study was divided into an acute seizure test (32 mice distributed into 4 groups) and a chronic kindling model study (40 mice distributed into 5 groups), followed by gene expression analysis and immunohistochemistry. The kindling model lasted 26 days and took 13 subconvulsive doses of pentylenetetrazole (PTZ) to completely kindle the mice in the PTZ control group. Gene expression changes in the A1Rs, potassium inwardly-rectifying channel 3.2 (Kir3.2), and ENT1 in the brain tissue samples of the mice following treatment with LEV were analyzed using reverse transcription-quantitative polymerase chain reaction, and immunohistochemistry was performed for the A1R protein expression. Results Docking studies predicted a significant interaction of LEV with A1Rs and ENT1 proteins. Results from the acute testing revealed that caffeine (100 mg/kg) and 8-cyclopentyl-1,3-dipropylxanthine (25 mg/kg) significantly reversed the antiseizure effects of LEV by reversing the percent protection and shortening the onset of the first myoclonic jerk (FMJ) and generalized clonic seizures (GCSs). In the PTZ-induced kindling, LEV demonstrated an increased gene expression of A1Rs and Kir3.2 in the brain. LEV also significantly reduced the gene expression of ENT1. Furthermore, the immunohistochemical analysis showed that LEV increased the protein expression of A1Rs in the brain. Conclusion Based on these results, it can be concluded that LEV modulates epileptogenesis by acting on the adenosine pathway in the central nervous system.
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Affiliation(s)
- Muhammad JAMAL
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, Faculty of Sciences, University of Karachi, Karachi,
Pakistan
| | - Muhammad AZAM
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, Faculty of Sciences, University of Karachi, Karachi,
Pakistan
| | - Salman Ali KHAN
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, Faculty of Sciences, University of Karachi, Karachi,
Pakistan
| | - Zaheer UL-HAQ
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, Faculty of Sciences, University of Karachi, Karachi,
Pakistan
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, Faculty of Sciences, University of Karachi, Karachi,
Pakistan
| | - Shabana Usman SIMJEE
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, Faculty of Sciences, University of Karachi, Karachi,
Pakistan
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, Faculty of Sciences, University of Karachi, Karachi,
Pakistan
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Metcalf CS, Gagangras S, Bulaj G, White HS. Synergistic effects of the galanin analog 810-2 with the antiseizure medication levetiracetam in rodent seizure models. Epilepsia 2022; 63:3090-3099. [PMID: 36177529 DOI: 10.1111/epi.17420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/25/2022] [Accepted: 09/26/2022] [Indexed: 01/11/2023]
Abstract
OBJECTIVE The use of many antiseizure medications (ASMs) is limited due to pharmacoresistance and dose-limiting side effects, suggesting an unmet need for novel therapeutic approaches. The neuropeptide galanin reduces seizures in several preclinical seizure and epilepsy models, but its clinical utility is limited due to rapid metabolism and poor blood-brain barrier penetration. The lead galanin analog 810-2 is systemically bioavailable and reduces seizures when administered alone. Further development of this analog, with the potential for use as an add-on therapy in patients with epilepsy, requires a better understanding of the use of this analog in combination with approved ASMs. We sought to evaluate 810-2 in combination with commonly used ASMs in rodent models of seizures. METHODS The mouse 6-Hz seizure assay was used to test efficacy of 810-2 in combination with levetiracetam (LEV), valproic acid (VPA), or lacosamide (LCM) using a 1:1 dose ratio in isobolographic studies. Further characterization was performed for the combination of 810-2 and LEV in the mouse corneal kindling and rat 6-Hz assays. RESULTS Whereas the combination of 810-2 with VPA and LCM yielded additive interactions, the combination of 810-2 with LEV demonstrated a synergistic interaction in the mouse 6-Hz assay. Supra-additive effects were also observed in the mouse corneal kindling and rat 6-Hz assays for this combination. SIGNIFICANCE The combination of 810-2 with LEV suggests the potential for this galanin analog to be further developed as an add-on therapy for patients with epilepsy, particularly when coadministered with LEV.
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Affiliation(s)
- Cameron S Metcalf
- Epilepsy Therapy Screening Program Contract Site, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - Saurabh Gagangras
- Epilepsy Therapy Screening Program Contract Site, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - Grzegorz Bulaj
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA, USA
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Yuan D, Yang G, Wu W, Li Q, Xu D, Ntim M, Jiang C, Liu J, Zhang Y, Wang Y, Zhu D, Kundu S, Li A, Xiao Z, Ma Q, Li S. Reducing Nav1.6 expression attenuates the pathogenesis of Alzheimer's disease by suppressing BACE1 transcription. Aging Cell 2022; 21:e13593. [PMID: 35353937 PMCID: PMC9124306 DOI: 10.1111/acel.13593] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/12/2022] [Accepted: 03/07/2022] [Indexed: 12/14/2022] Open
Abstract
Aberrant increases in neuronal network excitability may contribute to cognitive deficits in Alzheimer's disease (AD). However, the mechanisms underlying hyperexcitability of neurons are not fully understood. Voltage‐gated sodium channels (VGSC or Nav), which are involved in the formation of excitable cell's action potential and can directly influence the excitability of neural networks, have been implicated in AD‐related abnormal neuronal hyperactivity and higher incidence of spontaneous non‐convulsive seizures. Here, we have shown that the reduction of VGSC α‐subunit Nav1.6 (by injecting adeno‐associated virus (AAV) with short hairpin RNA (shRNA) into the hippocampus) rescues cognitive impairments and attenuates synaptic deficits in APP/PS1 transgenic mice. Concurrently, amyloid plaques in the hippocampus and levels of soluble Aβ are significantly reduced. Interfering with Nav1.6 reduces the transcription level of β‐site APP‐cleaving enzyme 1 (BACE1), which is Aβ‐dependent. In the presence of Aβ oligomers, knockdown of Nav1.6 reduces intracellular calcium overload by suppressing reverse sodium–calcium exchange channel, consequently increasing inactive NFAT1 (the nuclear factor of activated T cells) levels and thus reducing BACE1 transcription. This mechanism leads to a reduction in the levels of Aβ in APP/PS1 transgenic mice, alleviates synaptic loss, improves learning and memory disorders in APP/PS1 mice after downregulating Nav1.6 in the hippocampus. Our study offers a new potential therapeutic strategy to counteract hippocampal hyperexcitability and subsequently rescue cognitive deficits in AD by selective blockade of Nav1.6 overexpression and/or hyperactivity.
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Affiliation(s)
- De‐Juan Yuan
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
- Department of Neurology and Clinical Research Center of Neurological Disease The Second Affiliated Hospital of Soochow University Suzhou China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Institute of Neuroscience Soochow University Suzhou China
- The Affiliated Wuxi No. 2 People’s Hospital of Nanjing Medical University Wuxi China
| | - Guang Yang
- Department of Thoracic Surgery Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Wei Wu
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
| | - Qi‐Fa Li
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
| | - De‐en Xu
- Department of Neurology and Clinical Research Center of Neurological Disease The Second Affiliated Hospital of Soochow University Suzhou China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Institute of Neuroscience Soochow University Suzhou China
- The Affiliated Wuxi No. 2 People’s Hospital of Nanjing Medical University Wuxi China
| | - Michael Ntim
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
| | - Chun‐Yan Jiang
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
| | - Ji‐Chuan Liu
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
- Department of Neurology and Clinical Research Center of Neurological Disease The Second Affiliated Hospital of Soochow University Suzhou China
| | - Yue Zhang
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
| | - Ying‐Zi Wang
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
| | - Dan‐Dan Zhu
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
| | - Supratik Kundu
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
| | - Ai‐Ping Li
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
| | - Zhi‐Cheng Xiao
- Development and Stem Cells Program Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology Monash University Melbourne Victoria Australia
| | - Quan‐Hong Ma
- Department of Neurology and Clinical Research Center of Neurological Disease The Second Affiliated Hospital of Soochow University Suzhou China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Institute of Neuroscience Soochow University Suzhou China
| | - Shao Li
- Department of Physiology College of Basic Medical Sciences Liaoning Provincial Key Laboratory of Cerebral Diseases National‐Local Joint Engineering Research Center for Drug‐Research and Development (R&D) of Neurodegenerative Diseases Dalian Medical University Dalian China
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Ebada MA, Alkanj S, Ebada M, Abdelkarim AH, Diab A, Aziz MAE, Soliman AM, Fayed N, Bahbah EI, Negida A. Safety and Efficacy of Levetiracetam for the Management of Levodopa- Induced Dyskinesia in Patients with Parkinson's Disease: A Systematic Review. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2020; 18:317-325. [PMID: 30868968 DOI: 10.2174/1871527318666190314101314] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/28/2019] [Accepted: 03/07/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Levetiracetam, a novel antiepileptic drug, has shown antidyskinetic effects in experimental animal models of Parkinson's disease (PD). The tolerability and efficacy of levetiracetam in reducing the levodopa-induced dyskinesia (LID) in PD patients have not been established. Therefore, this study aims to synthesize evidence from published prospective clinical trials about the efficacy of levetiracetam for the management of LID in PD patients. METHODS We followed the PRISMA statement guidelines during the preparation of this systematic review. A computer literature search of PubMed, EBSCO, Scopus, MEDLINE, and the web of science was carried out. We selected prospective clinical trials assessing the anti-dyskinetic efficacy of levetiracetam for treating LID in patients with PD. The Abnormal Involuntary Movement Scale (AIMS), Clinical Global Impression Score (GCI), UPDRS III, and UPDRS IV were considered as the primary outcome measures; their data were extracted and reviewed. RESULTS Our review included seven clinical trials with a total of 150 patients. Of them, three studies were randomized controlled trials, and the remaining were open-label single arm trials. Four studies reported poor tolerability of the levetiracetam with mild anti-dyskinetic effects. Levetiracetam slightly improved the UPDRS-IV and AIMS scores with small effect size. In the remaining three studies, levetiracetam failed to exhibit any anti-dyskinetic effects. CONCLUSION Current evidence does not support the efficacy of the levetiracetam for treating LID in PD patients, however, due to the limited number of published randomized control trials (RCTs), further RCTs are required.
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Affiliation(s)
- Mahmoud A Ebada
- Faculty of Medicine, Zagazig University, Zagazig, Egypt.,Medical Research Group of Egypt
| | - Souad Alkanj
- Faculty of Medicine, Zagazig University, Zagazig, Egypt.,Medical Research Group of Egypt
| | | | - Ahmed H Abdelkarim
- Faculty of Medicine, Zagazig University, Zagazig, Egypt.,Medical Research Group of Egypt
| | - Ahmed Diab
- Medical Research Group of Egypt.,Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Mohamed A E Aziz
- Medical Research Group of Egypt.,Omr Shahin Mental Hospital, Egypt
| | - Ahmed M Soliman
- Medical Research Group of Egypt.,Faculty of Medicine, Al-Azhar University, Damietta, Egypt
| | - Notila Fayed
- Faculty of Medicine, Zagazig University, Zagazig, Egypt.,Medical Research Group of Egypt
| | - Eshak I Bahbah
- Medical Research Group of Egypt.,Faculty of Medicine, Al-Azhar University, Damietta, Egypt
| | - Ahmed Negida
- Faculty of Medicine, Zagazig University, Zagazig, Egypt.,Medical Research Group of Egypt
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Metcalf CS, Huff J, Thomson KE, Johnson K, Edwards SF, Wilcox KS. Evaluation of antiseizure drug efficacy and tolerability in the rat lamotrigine-resistant amygdala kindling model. Epilepsia Open 2019; 4:452-463. [PMID: 31440726 PMCID: PMC6698678 DOI: 10.1002/epi4.12354] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 07/09/2019] [Accepted: 07/21/2019] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE The lamotrigine-resistant amygdala kindling model uses repeated administration of a low dose of lamotrigine during the kindling process to produce resistance to lamotrigine, which also extends to some other antiseizure drugs (ASDs). This model of pharmacoresistant epilepsy has been incorporated into the testing scheme utilized by the Epilepsy Therapy Screening Program (ETSP). Although some ASDs have been evaluated in this model, a comprehensive evaluation of ASD prototypes has not been reported. METHODS Following depth electrode implantation and recovery, rats were exposed to lamotrigine (5 mg/kg, i.p.) prior to each stimulation during the kindling development process (~3 weeks). A test dose of lamotrigine was used to confirm that fully kindled rats were lamotrigine-resistant. Efficacy (unambiguous protection against electrically elicited convulsive seizures) was defined as a Racine score < 3 in the absence of overt compound-induced side effects. Various ASDs, comprising several mechanistic classes, were administered to fully kindled, lamotrigine-resistant rats. Where possible, multiple doses of each drug were administered in order to obtain median effective dose (ED50) values. RESULTS Five sodium channel blockers tested (eslicarbazepine, lacosamide, lamotrigine, phenytoin, and rufinamide) were either not efficacious or effective only at doses that were not well-tolerated in this model. In contrast, compounds targeting either GABA receptors (clobazam, clonazepam, phenobarbital) or GABA-uptake proteins (tiagabine) produced dose-dependent efficacy against convulsive seizures. Compounds acting to modulate Ca2+ channels show differential activity: Ethosuximide was not effective, whereas gabapentin was moderately efficacious. Ezogabine and valproate were also highly effective, whereas topiramate and levetiracetam were not effective at the doses tested. SIGNIFICANCE These results strengthen the conclusion that the lamotrigine-resistant amygdala kindling model demonstrates pharmacoresistance to certain ASDs, including, but not limited to, sodium channel blockers, and supports the utility of the model for helping to identify compounds with potential efficacy against pharmacoresistant seizures.
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Affiliation(s)
- Cameron S. Metcalf
- Anticonvulsant Drug Development Program, Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Jennifer Huff
- Anticonvulsant Drug Development Program, Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Kyle E. Thomson
- Anticonvulsant Drug Development Program, Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Kristina Johnson
- Anticonvulsant Drug Development Program, Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Sharon F. Edwards
- Anticonvulsant Drug Development Program, Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Karen S. Wilcox
- Anticonvulsant Drug Development Program, Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
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Age-Dependency of Levetiracetam Effects on Exocytotic GABA Release from Nerve Terminals in the Hippocampus and Cortex in Norm and After Perinatal Hypoxia. Cell Mol Neurobiol 2019; 39:701-714. [PMID: 31006090 DOI: 10.1007/s10571-019-00676-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/10/2019] [Indexed: 10/27/2022]
Abstract
Perinatal hypoxia can lead to multiple chronic neurological deficits, e.g., mental retardation, behavioral abnormalities, and epilepsy. Levetiracetam (LEV), 2S-(2-oxo-1-pyrrolidiny1) butanamide, is an anticonvulsant drug with proven efficiency in treating patients with focal and generalized seizures. Rats were underwent hypoxia and seizures at the age of 10-12 postnatal days (pd). The ambient level and depolarization-induced exocytotic release of [3H]GABA (γ-aminobutyric acid) were analyzed in nerve terminals in the hippocampus and cortex during development at the age of pd 17-19 and pd 24-26 (infantile stage), pd 38-40 (puberty) and pd 66-73 (young adults) in norm and after perinatal hypoxia. LEV had no effects on the ambient [3H]GABA level. The latter increased during development and was further elevated after perinatal hypoxia in nerve terminals in the hippocampus during the whole period and in the cortex in young adults. Exocytotic [3H]GABA release from nerve terminals increased after perinatal hypoxia during development in the hippocampus and cortex, however this effect was preserved at all ages during blockage of GABA transporters by NO-711 in the hippocampus only. LEV realized its anticonvulsant effects at the presynaptic site through an increase in exocytotic release of GABA. LEV exerted more significant effect after perinatal hypoxia than in norm. Action of LEV was strongly age-dependent and can be registered in puberty and young adults, but the drug was inert at the infantile stage.
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Pastukhov A, Borisova T. Levetiracetam-mediated improvement of decreased NMDA-induced glutamate release from nerve terminals during hypothermia. Brain Res 2018; 1699:69-78. [PMID: 30343685 DOI: 10.1016/j.brainres.2018.06.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/09/2018] [Accepted: 06/28/2018] [Indexed: 01/12/2023]
Abstract
A combination of a beneficial neuroprotectant, hypothermia, with targeted medication is a perspective therapeutic approach. Here, we analyzed both non-specific (deep and profound hypothermia, 27 °C and 17 °C, respectively) and targeted (anticonvulsant drug levetiracetam) modulation of l-[14C]glutamate release induced by activation of presynaptic NMDA, AMPA, and kainate receptors in rat brain nerve terminals (synaptosomes). Gradual dynamics of hypothermia-mediated decrease in synaptosomal l-[14C]glutamate release evoked by the receptor agonists NMDA-, AMPA-, and kainate (250 μM) has been demonstrated that can be of value for the justification of optimal temperature regimes in therapeutic hypothermia. 250 μM NMDA-induced l-[14C]glutamate release from nerve terminals was higher in the presence of levetiracetam (100 μM) as compared to that without the drug. Despite levetiracetam effects decreased in hypothermia, combined application of hypothermia and levetiracetam resulted in higher NMDA-induced l-[14C]glutamate release from nerve terminals as compared to that without the drug. These effects were not revealed for synaptosomal AMPA- and kainate-induced l-[14C]glutamate release in the presence of levetiracetam at the similar concentration. Therefore, levetiracetam administration significantly mitigated a hypothermia-induced decrease in NMDA receptor response at the presynaptic level and can be used for the targeted neurocorrection to reduce side effects of hypothermia in cardiac surgery. However, levetiracetam-mediated improvement of NMDA receptor response is not applicable in stroke, brain trauma and neonatal asphyxia therapies, where the main neuroprotective action of hypothermia is associated with prevention of damaging consequence of pre-existing acute glutamate exitotoxicity.
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Affiliation(s)
- A Pastukhov
- The Department of Neurochemistry, Palladin Institute of Biochemistry, NAS of Ukraine, 9 Leontovicha Street, Kiev 01030, Ukraine.
| | - T Borisova
- The Department of Neurochemistry, Palladin Institute of Biochemistry, NAS of Ukraine, 9 Leontovicha Street, Kiev 01030, Ukraine.
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Klitgaard H, Matagne A, Nicolas JM, Gillard M, Lamberty Y, De Ryck M, Kaminski RM, Leclercq K, Niespodziany I, Wolff C, Wood M, Hannestad J, Kervyn S, Kenda B. Brivaracetam: Rationale for discovery and preclinical profile of a selective SV2A ligand for epilepsy treatment. Epilepsia 2016; 57:538-48. [PMID: 26920914 DOI: 10.1111/epi.13340] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/26/2016] [Indexed: 12/13/2022]
Abstract
Despite availability of effective antiepileptic drugs (AEDs), many patients with epilepsy continue to experience refractory seizures and adverse events. Achievement of better seizure control and fewer side effects is key to improving quality of life. This review describes the rationale for the discovery and preclinical profile of brivaracetam (BRV), currently under regulatory review as adjunctive therapy for adults with partial-onset seizures. The discovery of BRV was triggered by the novel mechanism of action and atypical properties of levetiracetam (LEV) in preclinical seizure and epilepsy models. LEV is associated with several mechanisms that may contribute to its antiepileptic properties and adverse effect profile. Early findings observed a moderate affinity for a unique brain-specific LEV binding site (LBS) that correlated with anticonvulsant effects in animal models of epilepsy. This provided a promising molecular target and rationale for identifying selective, high-affinity ligands for LBS with potential for improved antiepileptic properties. The later discovery that synaptic vesicle protein 2A (SV2A) was the molecular correlate of LBS confirmed the novelty of the target. A drug discovery program resulted in the identification of anticonvulsants, comprising two distinct families of high-affinity SV2A ligands possessing different pharmacologic properties. Among these, BRV differed significantly from LEV by its selective, high affinity and differential interaction with SV2A as well as a higher lipophilicity, correlating with more potent and complete seizure suppression, as well as a more rapid brain penetration in preclinical models. Initial studies in animal models also revealed BRV had a greater antiepileptogenic potential than LEV. These properties of BRV highlight its promising potential as an AED that might provide broad-spectrum efficacy, associated with a promising tolerability profile and a fast onset of action. BRV represents the first selective SV2A ligand for epilepsy treatment and may add a significant contribution to the existing armamentarium of AEDs.
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