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Devinsky O, Jones NA, Cunningham MO, Jayasekera BAP, Devore S, Whalley BJ. Cannabinoid treatments in epilepsy and seizure disorders. Physiol Rev 2024; 104:591-649. [PMID: 37882730 DOI: 10.1152/physrev.00049.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 10/17/2023] [Accepted: 10/22/2023] [Indexed: 10/27/2023] Open
Abstract
Cannabis has been used to treat convulsions and other disorders since ancient times. In the last few decades, preclinical animal studies and clinical investigations have established the role of cannabidiol (CBD) in treating epilepsy and seizures and support potential therapeutic benefits for cannabinoids in other neurological and psychiatric disorders. Here, we comprehensively review the role of cannabinoids in epilepsy. We briefly review the diverse physiological processes mediating the central nervous system response to cannabinoids, including Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiol, and terpenes. Next, we characterize the anti- and proconvulsive effects of cannabinoids from animal studies of acute seizures and chronic epileptogenesis. We then review the clinical literature on using cannabinoids to treat epilepsy, including anecdotal evidence and case studies as well as the more recent randomized controlled clinical trials that led to US Food and Drug Administration approval of CBD for some types of epilepsy. Overall, we seek to evaluate our current understanding of cannabinoids in epilepsy and focus future research on unanswered questions.
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Affiliation(s)
- Orrin Devinsky
- Department of Neurology, NYU Grossman School of Medicine, New York, New York, United States
- Department of Neurosurgery, NYU Grossman School of Medicine, New York, New York, United States
- Department of Psychiatry, NYU Grossman School of Medicine, New York, New York, United States
| | | | - Mark O Cunningham
- Discipline of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - B Ashan P Jayasekera
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Department of Neurosurgery, Royal Victoria Hospital, Newcastle upon Tyne, United Kingdom
| | - Sasha Devore
- Department of Neurology, NYU Grossman School of Medicine, New York, New York, United States
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Suleymanova EM, Karan AA, Borisova MA, Volobueva MN, Bolshakov AP. Expression of Cytokines and Neurodegeneration in the Rat Hippocampus and Cortex in the Lithium-Pilocarpine Model of Status Epilepticus and the Role of Modulation of Endocannabinoid System. Int J Mol Sci 2023; 24:ijms24076509. [PMID: 37047481 PMCID: PMC10095234 DOI: 10.3390/ijms24076509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/26/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023] Open
Abstract
A significant body of evidence shows that neuroinflammation is one of the key processes in the development of brain pathology in trauma, neurodegenerative disorders, and epilepsy. Various brain insults, including severe and prolonged seizure activity during status epilepticus (SE), trigger proinflammatory cytokine release. We investigated the expression of the proinflammatory cytokines interleukin-1β (Il1b) and interleukin-6 (Il6), and anti-inflammatory fractalkine (Cx3cl1) in the hippocampus, entorhinal cortex, and neocortex of rats 24 h, 7 days, and 5 months after lithium-pilocarpine SE. We studied the relationship between cytokine expression and neuronal death in the hippocampus and evaluated the effect of modulation of endocannabinoid receptors on neuroinflammation and neurodegeneration after SE. The results of the present study showed that inhibition of endocannabinoid CB1 receptors with AM251 early after SE had a transient neuroprotective effect that was absent in the chronic period and did not affect the development of spontaneous seizures after SE. At the same time, AM251 reduced the expression of Il6 in the chronic period after SE. Higher Cx3cl1 levels were found in rats with more prominent hippocampal neurodegeneration.
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Xue B, Zhang X, Wang Y. Bench to bedside: Multiple facets of cannabinoid control in epilepsy. Neurochem Int 2020; 141:104898. [PMID: 33159980 DOI: 10.1016/j.neuint.2020.104898] [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: 07/20/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 11/27/2022]
Abstract
Epilepsy is a neurological disease recognized as the consequence of excessive neuronal excitability. Endocannabinoid system, the critical regulator of synaptic inhibition in brain, was supposed to be closely involved in epilepsy. Cannabinoid receptors mostly locate on presynaptic terminals of both excitatory and inhibitory neurons, but with characteristic distribution varying in different brain areas and synapses. Endocannabinoids are synthesized in postsynaptic neurons and retrogradely act on presynaptic cannabinoid receptors. Accumulating evidence suggest that the expression of cannabinoid receptors and synthesis or breakdown of endocannabinoids were cell-type specifically altered and spatiotemporally regulated in seizures, and intervention of the expression of cannabinoid receptors or the level of endocannabinoids could affect seizure actions. Further in clinic, cannabidiol as an add-on treatment could reduce seizures in patients with treatment-resistant epilepsy, but the underlying mechanisms are still unclear and independent of the endocannabinoid system. Therefore, we review recent advances from bench to bedside, to address the cannabinoid control on seizures, discuss the existing confusion in current studies and provide directions for further research, which may be clinically important for the design of cannabinoid-based precise therapeutic interventions for epilepsy.
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Affiliation(s)
- Bao Xue
- Institute of Brain Science and Disease, Qingdao University, No. 308, Ningxia Road, Qingdao, 266071, China; School of Basic Medicine, Qingdao University, No. 308, Ningxia Road, Qingdao, 266071, China
| | - Xia Zhang
- Institute of Brain Science and Disease, Qingdao University, No. 308, Ningxia Road, Qingdao, 266071, China
| | - Ying Wang
- Institute of Brain Science and Disease, Qingdao University, No. 308, Ningxia Road, Qingdao, 266071, China.
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Rosenberg EC, Patra PH, Whalley BJ. Therapeutic effects of cannabinoids in animal models of seizures, epilepsy, epileptogenesis, and epilepsy-related neuroprotection. Epilepsy Behav 2017; 70:319-327. [PMID: 28190698 PMCID: PMC5651410 DOI: 10.1016/j.yebeh.2016.11.006] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 11/03/2016] [Indexed: 12/21/2022]
Abstract
The isolation and identification of the discrete plant cannabinoids in marijuana revived interest in analyzing historical therapeutic claims made for cannabis in clinical case studies and anecdotes. In particular, sources as old as the 11th and 15th centuries claimed efficacy for crude marijuana extracts in the treatment of convulsive disorders, prompting a particularly active area of preclinical research into the therapeutic potential of plant cannabinoids in epilepsy. Since that time, a large body of literature has accumulated describing the effects of several of the >100 individual plant cannabinoids in preclinical models of seizures, epilepsy, epileptogenesis, and epilepsy-related neuroprotection. We surveyed the literature for relevant reports of such plant cannabinoid effects and critically reviewed their findings. We found that acute CB1R agonism in simple models of acute seizures in rodents typically produces anti-convulsant effects whereas CB1R antagonists exert converse effects in the same models. However, when the effects of such ligands are examined in more complex models of epilepsy, epileptogenesis and neuroprotection, a less simplistic narrative emerges. Here, the complex interactions between (i) brain regions involved in a given model, (ii) relative contributions of endocannabinoid signaling to modulation of synaptic transmission in such areas, (iii) multi-target effects, (iv) cannabinoid type 1 and type 2 receptor signaling interactions and, (v) timing, (vi) duration and (vii) localization of ligand administration suggest that there is both anti-epileptic therapeutic potential and a pro-epileptic risk in up- and down-regulation of endocannabinoid signaling in the central nervous system. Factors such receptor desensitization and specific pharmacology of ligands used (e.g. full vs partial agonists and neutral antagonists vs inverse agonists) also appear to play an important role in the effects reported. Furthermore, the effects of several plant cannabinoids, most notably cannabidiol (CBD) and cannabidavarin (CBDV), in models of seizures, epilepsy, epileptogenesis, and neuroprotection are less ambiguous, and consistent with reports of therapeutically beneficial effects of these compounds in clinical studies. However, continued paucity of firm information regarding the therapeutic molecular mechanism of CBD/CBDV highlights the continued need for research in this area in order to identify as yet under-exploited targets for drug development and raise our understanding of treatment-resistant epilepsies. The recent reporting of positive results for cannabidiol treatment in two Phase III clinical trials in treatment-resistant epilepsies provides pivotal evidence of clinical efficacy for one plant cannabinoid in epilepsy. Moreover, risks and/or benefits associated with the use of unlicensed Δ9-THC containing marijuana extracts in pediatric epilepsies remain poorly understood. Therefore, in light of these paradigm-changing clinical events, the present review's findings aim to drive future drug development for newly-identified targets and indications, identify important limitations of animal models in the investigation of plant cannabinoid effects in the epilepsies, and focuses future research in this area on specific, unanswered questions regarding the complexities of endocannabinoid signaling in epilepsy. This article is part of a Special Issue titled Cannabinoids and Epilepsy.
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Affiliation(s)
- Evan C. Rosenberg
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA
| | - Pabitra H. Patra
- Department of Pharmacy, School of Chemistry, Food & Nutritional Sciences and Pharmacy, University of Reading, Whiteknights, Reading, Berkshire RG6 6AP, UK
| | - Benjamin J. Whalley
- Department of Pharmacy, School of Chemistry, Food & Nutritional Sciences and Pharmacy, University of Reading, Whiteknights, Reading, Berkshire RG6 6AP, UK,Corresponding author: (B.J. Whalley)
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Long-Term Intake of Uncaria rhynchophylla Reduces S100B and RAGE Protein Levels in Kainic Acid-Induced Epileptic Seizures Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:9732854. [PMID: 28386293 PMCID: PMC5343263 DOI: 10.1155/2017/9732854] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/13/2017] [Accepted: 01/24/2017] [Indexed: 12/19/2022]
Abstract
Epileptic seizures are crucial clinical manifestations of recurrent neuronal discharges in the brain. An imbalance between the excitatory and inhibitory neuronal discharges causes brain damage and cell loss. Herbal medicines offer alternative treatment options for epilepsy because of their low cost and few side effects. We established a rat epilepsy model by injecting kainic acid (KA, 12 mg/kg, i.p.) and subsequently investigated the effect of Uncaria rhynchophylla (UR) and its underlying mechanisms. Electroencephalogram and epileptic behaviors revealed that the KA injection induced epileptic seizures. Following KA injection, S100B levels increased in the hippocampus. This phenomenon was attenuated by the oral administration of UR and valproic acid (VA, 250 mg/kg). Both drugs significantly reversed receptor potentiation for advanced glycation end product proteins. Rats with KA-induced epilepsy exhibited no increase in the expression of metabotropic glutamate receptor 3, monocyte chemoattractant protein 1, and chemokine receptor type 2, which play a role in inflammation. Our results provide novel and detailed mechanisms, explaining the role of UR in KA-induced epileptic seizures in hippocampal CA1 neurons.
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Wong JC, Escayg A. Turning Up the Heat on Endocannabinoid Signaling. Epilepsy Curr 2016; 16:414-415. [PMID: 27857628 PMCID: PMC5106110 DOI: 10.5698/1535-7511-16.6.414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Fox CK, Glass HC, Sidney S, Smith SE, Fullerton HJ. Neonatal seizures triple the risk of a remote seizure after perinatal ischemic stroke. Neurology 2016; 86:2179-86. [PMID: 27164703 DOI: 10.1212/wnl.0000000000002739] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 03/01/2016] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES To determine incidence rates and risk factors of remote seizure after perinatal arterial ischemic stroke. METHODS We retrospectively identified a population-based cohort of children with perinatal arterial ischemic stroke (presenting acutely or in a delayed fashion) from a large Northern Californian integrated health care system. We determined incidence and predictors of a remote seizure (unprovoked seizure after neonatal period, defined as 28 days of life) by survival analyses, and measured epilepsy severity in those with active epilepsy (≥1 remote seizure and maintenance anticonvulsant treatment) at last follow-up. RESULTS Among 87 children with perinatal stroke, 40 (46%) had a seizure in the neonatal period. During a median follow-up of 7.1 years (interquartile range 3.2-10.5), 37 children had ≥1 remote seizure. Remote seizure risk was highest during the first year of life, with a 20% (95% confidence interval [CI] 13%-30%) cumulative incidence by 1 year of age, 46% (CI 35%-58%) by 5 years, and 54% (CI 41%-67%) by 10 years. Neonatal seizures increased the risk of a remote seizure (hazard ratio 2.8, CI 1.3-5.8). Children with neonatal seizures had a 69% (CI 48%-87%) cumulative incidence of remote seizure by age 10 years. Among the 24 children with active epilepsy at last follow-up, 8 (33%) were having monthly seizures despite an anticonvulsant and 7 (29%) were on more than one anticonvulsant. CONCLUSIONS Remote seizures and epilepsy, including medically refractory epilepsy, are common after perinatal stroke. Neonatal seizures are associated with nearly 3-fold increased remote seizure risk.
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Affiliation(s)
- Christine K Fox
- From the Departments of Neurology (C.K.F., H.C.G., H.J.F.), Pediatrics (C.K.F., H.C.G., H.J.F.), and Epidemiology and Biostatistics (H.C.G.), University of California, San Francisco; the Division of Research (S.S.), Kaiser Permanente Northern California, Oakland; and the Division of Pediatric Neurology (S.E.S.), Kaiser Permanente Oakland Medical Center, CA.
| | - Hannah C Glass
- From the Departments of Neurology (C.K.F., H.C.G., H.J.F.), Pediatrics (C.K.F., H.C.G., H.J.F.), and Epidemiology and Biostatistics (H.C.G.), University of California, San Francisco; the Division of Research (S.S.), Kaiser Permanente Northern California, Oakland; and the Division of Pediatric Neurology (S.E.S.), Kaiser Permanente Oakland Medical Center, CA
| | - Stephen Sidney
- From the Departments of Neurology (C.K.F., H.C.G., H.J.F.), Pediatrics (C.K.F., H.C.G., H.J.F.), and Epidemiology and Biostatistics (H.C.G.), University of California, San Francisco; the Division of Research (S.S.), Kaiser Permanente Northern California, Oakland; and the Division of Pediatric Neurology (S.E.S.), Kaiser Permanente Oakland Medical Center, CA
| | - Sabrina E Smith
- From the Departments of Neurology (C.K.F., H.C.G., H.J.F.), Pediatrics (C.K.F., H.C.G., H.J.F.), and Epidemiology and Biostatistics (H.C.G.), University of California, San Francisco; the Division of Research (S.S.), Kaiser Permanente Northern California, Oakland; and the Division of Pediatric Neurology (S.E.S.), Kaiser Permanente Oakland Medical Center, CA
| | - Heather J Fullerton
- From the Departments of Neurology (C.K.F., H.C.G., H.J.F.), Pediatrics (C.K.F., H.C.G., H.J.F.), and Epidemiology and Biostatistics (H.C.G.), University of California, San Francisco; the Division of Research (S.S.), Kaiser Permanente Northern California, Oakland; and the Division of Pediatric Neurology (S.E.S.), Kaiser Permanente Oakland Medical Center, CA
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Abstract
Cannabis has been used for centuries to treat seizures. Recent anecdotal reports, accumulating animal model data, and mechanistic insights have raised interest in cannabis-based antiepileptic therapies. In this study, we review current understanding of the endocannabinoid system, characterize the pro- and anticonvulsive effects of cannabinoids [e.g., Δ9-tetrahydrocannabinol and cannabidiol (CBD)], and highlight scientific evidence from pre-clinical and clinical trials of cannabinoids in epilepsy. These studies suggest that CBD avoids the psychoactive effects of the endocannabinoid system to provide a well-tolerated, promising therapeutic for the treatment of seizures, while whole-plant cannabis can both contribute to and reduce seizures. Finally, we discuss results from a new multicenter, open-label study using CBD in a population with treatment-resistant epilepsy. In all, we seek to evaluate our current understanding of cannabinoids in epilepsy and guide future basic science and clinical studies.
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Affiliation(s)
- Evan C Rosenberg
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY, 10016, USA
| | - Richard W Tsien
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY, 10016, USA
| | - Benjamin J Whalley
- School of Pharmacy, The University of Reading, Whiteknights, Reading, RG6 6AP, UK
| | - Orrin Devinsky
- Department of Neurology, Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, 10016, UK.
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9
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Soltesz I, Alger BE, Kano M, Lee SH, Lovinger DM, Ohno-Shosaku T, Watanabe M. Weeding out bad waves: towards selective cannabinoid circuit control in epilepsy. Nat Rev Neurosci 2015; 16:264-77. [PMID: 25891509 PMCID: PMC10631555 DOI: 10.1038/nrn3937] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Endocannabinoids are lipid-derived messengers, and both their synthesis and breakdown are under tight spatiotemporal regulation. As retrograde signalling molecules, endocannabinoids are synthesized postsynaptically but activate presynaptic cannabinoid receptor 1 (CB1) receptors to inhibit neurotransmitter release. In turn, CB1-expressing inhibitory and excitatory synapses act as strategically placed control points for activity-dependent regulation of dynamically changing normal and pathological oscillatory network activity. Here, we highlight emerging principles of cannabinoid circuit control and plasticity, and discuss their relevance for epilepsy and related comorbidities. New insights into cannabinoid signalling may facilitate the translation of the recent interest in cannabis-related substances as antiseizure medications to evidence-based treatment strategies.
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Affiliation(s)
- Ivan Soltesz
- Department of Anatomy and Neurobiology, University of California, Irvine, California 92697, USA
| | - Bradley E Alger
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Sang-Hun Lee
- Department of Anatomy and Neurobiology, University of California, Irvine, California 92697, USA
| | - David M Lovinger
- Section on Synaptic Pharmacology, Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, US National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Takako Ohno-Shosaku
- Department of Impairment Study, Graduate School of Medical Science, Kanazawa University, Kanazawa 920-0942, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
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Attenuation of kainic acid-induced status epilepticus by inhibition of endocannabinoid transport and degradation in guinea pigs. Epilepsy Res 2015; 111:33-44. [PMID: 25769371 DOI: 10.1016/j.eplepsyres.2015.01.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 11/26/2014] [Accepted: 01/14/2015] [Indexed: 02/08/2023]
Abstract
Status epilepticus (SE) is a medical emergency associated with a high rate of mortality if not treated promptly. Exogenous and endogenous cannabinoids have been shown to possess anticonvulsant properties both in vivo and in vitro. Here we study the influence of endocannabinoid metabolism on the development of kainic acid-induced SE in guinea pigs. For this purpose, the inhibitors of endocannabinoid transport, AM404, and enzymatic (fatty acid amide hydrolase) degradation, URB597, were applied. Cannabinoid CB1 receptor antagonist, AM251, was also tested. Animal behavior as well as local electric field potentials in four structures: medial septum, hippocampus, entorhinal cortex and amygdala were analyzed when AM404 (120nmol), URB597 (4.8nmol) or AM251 (20nmol) were administrated alone or together with 0.4μg of kainic acid. All substances were injected i.c.v. AM404, URB597 or AM251 administered alone did not alter markedly local field potentials of all four studied structures in the long-term compared with their basal activity. AM404 and URB597 significantly alleviated kainic acid-induced SE, decreasing behavioral manifestations, duration of seizure events and SE in general without changing the amplitude of local field potentials. AM251 did not produce distinct effects on SE in terms of our experimental paradigm. There was no apparent change of the seizure initiation pattern when kainic acid was coadministrated with AM404, URB597 or AM251. The present study provides electrophysiologic and behavioral evidences that inhibition of endocannabinoid metabolism plays a protective role against kainic acid-induced SE and may be employed for therapeutic purposes. Further investigations of the influences of cannabinoid-related compounds on SE genesis and especially epileptogenesis are required.
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Analysis in conditional cannabinoid 1 receptor-knockout mice reveals neuronal subpopulation-specific effects on epileptogenesis in the kindling paradigm. Neurobiol Dis 2015; 73:334-47. [DOI: 10.1016/j.nbd.2014.08.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 08/01/2014] [Indexed: 01/04/2023] Open
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Abstract
The antiepileptic potential of Cannabis sativa preparations has been historically recognized. Recent changes in legal restrictions and new well-documented cases reporting remarkably strong beneficial effects have triggered an upsurge in exploiting medical marijuana in patients with refractory epilepsy. Parallel research efforts in the last decade have uncovered the fundamental role of the endogenous cannabinoid system in controlling neuronal network excitability raising hopes for cannabinoid-based therapeutic approaches. However, emerging data show that patient responsiveness varies substantially, and that cannabis administration may sometimes even exacerbate seizures. Qualitative and quantitative chemical variability in cannabis products and personal differences in the etiology of seizures, or in the pathological reorganization of epileptic networks, can all contribute to divergent patient responses. Thus, the consensus view in the neurologist community is that drugs modifying the activity of the endocannabinoid system should first be tested in clinical trials to establish efficacy, safety, dosing, and proper indication in specific forms of epilepsies. To support translation from anecdote-based practice to evidence-based therapy, the present review first introduces current preclinical and clinical efforts for cannabinoid- or endocannabinoid-based epilepsy treatments. Next, recent advances in our knowledge of how endocannabinoid signaling limits abnormal network activity as a central component of the synaptic circuit-breaker system will be reviewed to provide a framework for the underlying neurobiological mechanisms of the beneficial and adverse effects. Finally, accumulating evidence demonstrating robust synapse-specific pathophysiological plasticity of endocannabinoid signaling in epileptic networks will be summarized to gain better understanding of how and when pharmacological interventions may have therapeutic relevance.
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Affiliation(s)
- István Katona
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony u. 43, Budapest, 1083, Hungary.
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13
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Auricular electroacupuncture reduced inflammation-related epilepsy accompanied by altered TRPA1, pPKCα, pPKCε, and pERk1/2 signaling pathways in kainic acid-treated rats. Mediators Inflamm 2014; 2014:493480. [PMID: 25147437 PMCID: PMC4131505 DOI: 10.1155/2014/493480] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 07/07/2014] [Accepted: 07/08/2014] [Indexed: 12/23/2022] Open
Abstract
Background. Inflammation is often considered to play a crucial role in epilepsy by affecting iron status and metabolism. In this study, we investigated the curative effect of auricular acupuncture and somatic acupuncture on kainic acid- (KA-) induced epilepsy in rats. Methods. We established an epileptic seizure model in rats by KA (12 mg, ip). The 2 Hz electroacupuncture (EA) was applied at auricular and applied at Zusanli and Shangjuxu (ST36-ST37) acupoints for 20 min for 3 days/week for 6 weeks beginning on the day following the KA injection. Results. The electrophysiological results indicated that neuron overexcitation occurred in the KA-treated rats. This phenomenon could be reversed among either the auricular EA or ST36-ST37 EA treatment, but not in the sham-control rats. The Western blot results revealed that TRPA1, but not TRPV4, was upregulated by injecting KA and could be attenuated by administering auricular or ST36-ST37 EA, but not in the sham group. In addition, potentiation of TRPA1 was accompanied by increased PKCα and reduced PKCε. Furthermore, pERK1/2, which is indicated in inflammation, was also increased by KA. Furthermore, the aforementioned mechanisms could be reversed by administering auricular EA and could be partially reversed by ST36-ST37 EA. Conclusions. These results indicate a novel mechanism for treating inflammation-associated epilepsy and can be translated into clinical therapy.
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14
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Pitkänen A, Huusko N, Ndode-Ekane XE, Kyyriäinen J, Lipponen A, Lipsanen A, Sierra A, Bolkvadze T. Gender issues in antiepileptogenic treatments. Neurobiol Dis 2014; 72 Pt B:224-32. [PMID: 24912075 DOI: 10.1016/j.nbd.2014.05.037] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Revised: 05/23/2014] [Accepted: 05/29/2014] [Indexed: 12/12/2022] Open
Abstract
Disease modification of epilepsy refers to the alleviation of epileptogenesis or comorbidities after genetic or acquired epileptogenic brain insults. There are currently 30 proof-of-concept experimental pharmacologic studies that have demonstrated some beneficial disease-modifying effects. None of these studies, however, has yet passed from the laboratory to the clinic. The International League Against Epilepsy and American Epilepsy Society working groups on antiepileptogenic (AEG) therapies recently released recommendations for conducting preclinical AEG studies, taking into account many of the critiques raised by previous study designs. One of the issues relates to the lack of analysis of AEG efficacy in both sexes. A review of the literature reveals that most of the preclinical studies have been performed using male rodents, whereas clinical study cohorts include both males and females. Therefore, it is important to determine whether sex differences should be taken into account to a greater extent than they have been historically at different phases of experimental studies. Here we address the following questions based on analysis of available experimental AEG studies: (a) whether sex differences should be considered when searching for novel AEG targets, (b) how sex differences can affect the preclinical AEG study designs and analysis of outcome measures, and (c) what factors should be considered when examining the effect of sex on outcome of clinical AEG trials or the clinical use of AEGs.
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Affiliation(s)
- Asla Pitkänen
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland; Department of Neurology, Kuopio University Hospital, PO Box 1777, FIN-70211 Kuopio, Finland.
| | - Noora Huusko
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - Xavier Ekolle Ndode-Ekane
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - Jenni Kyyriäinen
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - Anssi Lipponen
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - Anu Lipsanen
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - Alejandra Sierra
- Biomedical Imaging Unit, A. I. Virtanen Institute for Molecular Sciences, University of Eastern, Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - Tamuna Bolkvadze
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
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15
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Abstract
Descriptions of epileptic seizures and epilepsy date back to antiquity, and research into fundamental mechanisms of epilepsy in animal models, as well as patients, has been carried out for over a century. Studies of epileptogenesis, however, as distinct from ictogenesis, have been pursued for only a few decades, and antiepileptogenesis, the prevention of epilepsy or its progression, and the reversal of the epileptogenic process or cure, are relatively recent interests of the basic research community. The goal to develop antiepileptogenic interventions would be greatly facilitated by the identification of reliable biomarkers of epileptogenesis that could be used to create cost-effective, high-throughput screening models for potential antiepileptogenic compounds, as well as enrich patient populations and serve as surrogate endpoints for clinical trials. Without such biomarkers, the cost for clinical validation of antiepileptogenic interventions would be prohibitive. Epileptogenic mechanisms, antiepileptogenic interventions, and biomarkers are likely to be specific for the many different causes of epilepsy, which include genetic influences, cell loss and synaptic plasticity, malformations of cortical development, and autoimmune disorders, to name but a few. A high priority is currently being placed on investigations to elucidate fundamental mechanisms of epileptogenesis and identify biomarkers for specific models of human epilepsy, such as mesial temporal lobe epilepsy with hippocampal sclerosis, traumatic brain injury, and a variety of pediatric diseases, including tuberous sclerosis and West syndrome.
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Affiliation(s)
- Asla Pitkänen
- />Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- />Department of Neurology, Kuopio University Hospital, Kuopio, Finland
| | - Jerome Engel
- />Department of Neurology, Neurobiology, and Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, 710 Westwood Plaza, Los Angeles, CA 90095-1769 USA
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Simonato M, Löscher W, Cole AJ, Dudek FE, Engel J, Kaminski RM, Loeb JA, Scharfman H, Staley KJ, Velíšek L, Klitgaard H. Finding a better drug for epilepsy: preclinical screening strategies and experimental trial design. Epilepsia 2012; 53:1860-7. [PMID: 22708847 DOI: 10.1111/j.1528-1167.2012.03541.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The antiepileptic drugs (AEDs) introduced during the past two decades have provided several benefits: they offered new treatment options for symptomatic treatment of seizures, improved ease of use and tolerability, and lowered risk for hypersensitivity reactions and detrimental drug-drug interactions. These drugs, however, neither attenuated the problem of drug-refractory epilepsy nor proved capable of preventing or curing the disease. Therefore, new preclinical screening strategies are needed to identify AEDs that target these unmet medical needs. New therapies may derive from novel targets identified on the basis of existing hypotheses for drug-refractory epilepsy and the biology of epileptogenesis; from research on genetics, transcriptomics, and epigenetics; and from mechanisms relevant for other therapy areas. Novel targets should be explored using new preclinical screening strategies, and new technologies should be used to develop medium- to high-throughput screening models. In vivo testing of novel drugs should be performed in models mimicking relevant aspects of drug refractory epilepsy and/or epileptogenesis. To minimize the high attrition rate associated with drug development, which arises mainly from a failure to demonstrate sufficient clinical efficacy of new treatments, it is important to define integrated strategies for preclinical screening and experimental trial design. An important tool will be the discovery and implementation of relevant biomarkers that will facilitate a continuum of proof-of-concept approaches during early clinical testing to rapidly confirm or reject preclinical findings, and thereby lower the risk of the overall development effort. In this review, we overview some of the issues related to these topics and provide examples of new approaches that we hope will be more successful than those used in the past.
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Affiliation(s)
- Michele Simonato
- Section of Pharmacology, Department of Clinical and Experimental Medicine, University of Ferrara, and National Institute of Neuroscience, via Fossato di Mortara 17-19, Ferrara, Italy.
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Rattka M, Brandt C, Löscher W. Do proconvulsants modify or halt epileptogenesis? Pentylenetetrazole is ineffective in two rat models of temporal lobe epilepsy. Eur J Neurosci 2012; 36:2505-20. [DOI: 10.1111/j.1460-9568.2012.08143.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Hofmann ME, Frazier CJ. Marijuana, endocannabinoids, and epilepsy: potential and challenges for improved therapeutic intervention. Exp Neurol 2011; 244:43-50. [PMID: 22178327 DOI: 10.1016/j.expneurol.2011.11.047] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 11/25/2011] [Accepted: 11/29/2011] [Indexed: 10/14/2022]
Abstract
Phytocannabinoids isolated from the cannabis plant have broad potential in medicine that has been well recognized for many centuries. It is presumed that these lipid soluble signaling molecules exert their effects in both the central and peripheral nervous system in large part through direct interaction with metabotropic cannabinoid receptors. These same receptors are also targeted by a variety of endogenous cannabinoids including 2-arachidonoyl glycerol and anandamide. Significant effort over the last decade has produced an enormous advance in our understanding of both the cellular and the synaptic physiology of endogenous lipid signaling systems. This increase in knowledge has left us better prepared to carefully evaluate the potential for both natural and synthetic cannabinoids in the treatment of a variety of neurological disorders. In the case of epilepsy, long standing interest in therapeutic approaches that target endogenous cannabinoid signaling systems are, for the most part, not well justified by available clinical data from human epileptics. Nevertheless, basic science experiments have clearly indicated a key role for endogenous cannabinoid signaling systems in moment to moment regulation of neuronal excitability. Further it has become clear that these systems can both alter and be altered by epileptiform activity in a wide range of in vitro and in vivo models of epilepsy. Collectively these observations suggest clear potential for effective therapeutic modulation of endogenous cannabinoid signaling systems in the treatment of human epilepsy, and in fact, further highlight key obstacles that would need to be addressed to reach that goal.
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Affiliation(s)
- Mackenzie E Hofmann
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, USA
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Pro-epileptic effects of the cannabinoid receptor antagonist SR141716 in a model of audiogenic epilepsy. Epilepsy Res 2011; 96:250-6. [PMID: 21733658 DOI: 10.1016/j.eplepsyres.2011.06.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 06/09/2011] [Accepted: 06/11/2011] [Indexed: 01/06/2023]
Abstract
Endocannabinoid system and its CB1 receptors are suggested to provide endogeneous protection against seizures. The present study examines whether CB1 receptors contribute to resistance to seizures and kindling epileptogenesis in a model of audiogenic epilepsy. Three groups of Wistar rats were used: rats unsusceptible to audiogenic seizures, rats with acquired resistance to audiogenic seizures and rats with reproducible audiogenic running seizures. Chronic treatment with the CB1 receptor antagonist SR141716 (5 daily dosing of 30mg/kg) did not change innate resistance to audiogenic seizures in non-epileptic rats but reverted acquired seizure resistance in rats which lost their epileptic sensitivity with repeated testing. In the latter rats, audiogenic running seizures reappeared for at least two weeks after the end of treatment. In rats with reproducible seizure response, acutely, SR lengthened audiogenic seizures due to prolongation or appearance, de novo, of post-running limbic clonus without any effect on running seizure per se. This limbic component mimicked audiogenic kindling and indicated propagation of sound-induced brainstem seizure to the limbic forebrain. After chronic SR administration the incidence of the limbic clonus remained to be increased for at least two weeks. The present study supports the hypothesis about a role of CB1 receptors in endogeneous anticonvulsive mechanisms of the brain.
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Lin YW, Hsieh CL. Oral Uncaria rhynchophylla (UR) reduces kainic acid-induced epileptic seizures and neuronal death accompanied by attenuating glial cell proliferation and S100B proteins in rats. JOURNAL OF ETHNOPHARMACOLOGY 2011; 135:313-320. [PMID: 21402140 DOI: 10.1016/j.jep.2011.03.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 12/15/2010] [Accepted: 03/05/2011] [Indexed: 05/30/2023]
Abstract
AIM OF THE STUDY Epilepsy is a common clinical syndrome with recurrent neuronal discharges in cerebral cortex and hippocampus. Here we aim to determine the protective role of Uncaria rhynchophylla (UR), an herbal drug belong to Traditional Chinese Medicine (TCM), on epileptic rats. MATERIALS AND METHODS To address this issue, we tested the effect of UR on kainic acid (KA)-induced epileptic seizures and further investigate the underlying mechanisms. RESULTS Oral UR successfully decreased neuronal death and discharges in hippocampal CA1 pyramidal neurons. The population spikes (PSs) were decreased from 4.1 ± 0.4 mV to 2.1 ± 0.3 mV in KA-induced epileptic seizures and UR-treated groups, respectively. Oral UR protected animals from neuronal death induced by KA treatment (from 34 ± 4.6 to 191.7 ± 48.6 neurons/field) through attenuating glial cell proliferation and S100B protein expression but not GABAA and TRPV1 receptors. CONCLUSIONS The above results provide detail mechanisms underlying the neuroprotective action of UR on KA-induced epileptic seizure in hippocampal CA1 neurons.
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Affiliation(s)
- Yi-Wen Lin
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
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Abstract
Prevention of epileptogenesis after brain trauma is an unmet medical challenge. Recent molecular profiling studies have provided an insight into molecular changes that contribute to formation of ictogenic neuronal networks, including genes regulating synaptic or neuronal plasticity, cell death, proliferation, and inflammatory or immune responses. These mechanisms have been targeted to prevent epileptogenesis in animal models. Favourable effects have been obtained using immunosuppressants, antibodies blocking adhesion of leucocytes to endothelial cells, gene therapy driving expression of neurotrophic factors, pharmacological neurostimulation, or even with conventional antiepileptic drugs by administering them before the appearance of genetic epilepsy. Further studies are needed to clarify the optimum time window and aetiological specificity of treatments. Questions related to adverse events also need further consideration. Encouragingly, the recent experimental studies emphasise that the complicated process of epileptogenesis can be favourably modified, and that antiepileptogenesis as a treatment indication might not be an impossible mission.
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Affiliation(s)
- Asla Pitkänen
- Department of Neurobiology, A I Virtanen Institute for Molecular Sciences, University of Eastern Finland, and Department of Neurology, Kuopio University Hospital, Kuopio, Finland.
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