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Zhou C, Satpute V, Yip KL, Anderson LL, Hawkins N, Kearney J, Arnold JC. A high seizure burden increases several prostaglandin species in the hippocampus of a Scn1a +/- mouse model of Dravet syndrome. Prostaglandins Other Lipid Mediat 2024; 172:106836. [PMID: 38599513 DOI: 10.1016/j.prostaglandins.2024.106836] [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: 01/09/2024] [Revised: 04/02/2024] [Accepted: 04/05/2024] [Indexed: 04/12/2024]
Abstract
Dravet syndrome is an intractable epilepsy with a high seizure burden that is resistant to current anti-seizure medications. There is evidence that neuroinflammation plays a role in epilepsy and seizures, however few studies have specifically examined neuroinflammation in Dravet syndrome under conditions of a higher seizure burden. Here we used an established genetic mouse model of Dravet syndrome (Scn1a+/- mice), to examine whether a higher seizure burden impacts the number and morphology of microglia in the hippocampus. Moreover, we examined whether a high seizure burden influences classical inflammatory mediators in this brain region. Scn1a+/- mice with a high seizure burden induced by thermal priming displayed a localised reduction in microglial cell density in the granule cell layer and subgranular zone of the dentate gyrus, regions important to postnatal neurogenesis. However, microglial cell number and morphology remained unchanged in other hippocampal subfields. The high seizure burden in Scn1a+/- mice did not affect hippocampal mRNA expression of classical inflammatory mediators such as interleukin 1β and tumour necrosis factor α, but increased cyclooxygenase 2 (COX-2) expression. We then quantified hippocampal levels of prostanoids that arise from COX-2 mediated metabolism of fatty acids and found that Scn1a+/- mice with a high seizure burden displayed increased hippocampal concentrations of numerous prostaglandins, notably PGF2α, PGE2, PGD2, and 6-K-PGF1A, compared to Scn1a+/- mice with a low seizure burden. In conclusion, a high seizure burden increased hippocampal concentrations of various prostaglandin mediators in a mouse model of Dravet syndrome. Future studies could interrogate the prostaglandin pathways to further better understand their role in the pathophysiology of Dravet syndrome.
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Affiliation(s)
- Cilla Zhou
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia; Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Vaishali Satpute
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Ka Lai Yip
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Lyndsey L Anderson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Nicole Hawkins
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Jennifer Kearney
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Jonathon C Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia.
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2
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Manduca A, Buzzelli V, Rava A, Feo A, Carbone E, Schiavi S, Peruzzi B, D'Oria V, Pezzullo M, Pasquadibisceglie A, Polticelli F, Micale V, Kuchar M, Trezza V. Cannabidiol and positive effects on object recognition memory in an in vivo model of Fragile X Syndrome: Obligatory role of hippocampal GPR55 receptors. Pharmacol Res 2024; 203:107176. [PMID: 38583687 DOI: 10.1016/j.phrs.2024.107176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 04/03/2024] [Accepted: 04/04/2024] [Indexed: 04/09/2024]
Abstract
Cannabidiol (CBD), a non-psychotomimetic constituent of Cannabis sativa, has been recently approved for epileptic syndromes often associated with Autism spectrum disorder (ASD). However, the putative efficacy and mechanism of action of CBD in patients suffering from ASD and related comorbidities remain debated, especially because of the complex pharmacology of CBD. We used pharmacological, immunohistochemical and biochemical approaches to investigate the effects and mechanisms of action of CBD in the recently validated Fmr1-Δexon 8 rat model of ASD, that is also a model of Fragile X Syndrome (FXS), the leading monogenic cause of autism. CBD rescued the cognitive deficits displayed by juvenile Fmr1-Δexon 8 animals, without inducing tolerance after repeated administration. Blockade of CA1 hippocampal GPR55 receptors prevented the beneficial effect of both CBD and the fatty acid amide hydrolase (FAAH) inhibitor URB597 in the short-term recognition memory deficits displayed by Fmr1-Δexon 8 rats. Thus, CBD may exert its beneficial effects through CA1 hippocampal GPR55 receptors. Docking analysis further confirmed that the mechanism of action of CBD might involve competition for brain fatty acid binding proteins (FABPs) that deliver anandamide and related bioactive lipids to their catabolic enzyme FAAH. These findings demonstrate that CBD reduced cognitive deficits in a rat model of FXS and provide initial mechanistic insights into its therapeutic potential in neurodevelopmental disorders.
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Affiliation(s)
- Antonia Manduca
- Dept. Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy; Dept. Science, Roma Tre University, Rome, Italy; Neuroendocrinology, Metabolism and Neuropharmacology Unit, IRCCS Fondazione Santa Lucia, Rome, Italy.
| | | | | | | | | | | | - Barbara Peruzzi
- Bone Physiopathology Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Valentina D'Oria
- Confocal Microscopy Core Facility, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Marco Pezzullo
- Histology Core Facility, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | | | - Vincenzo Micale
- Dept. Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Martin Kuchar
- Forensic Laboratory of Biologically Active Substances, Dept. Chemistry of Natural Compounds, University of Chemistry and Technologies, Prague, Czech Republic; Psychedelic Research Center, National Institute of Mental Health, Klecany, Czech Republic
| | - Viviana Trezza
- Dept. Science, Roma Tre University, Rome, Italy; Neuroendocrinology, Metabolism and Neuropharmacology Unit, IRCCS Fondazione Santa Lucia, Rome, Italy.
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3
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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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4
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Javadzadeh Y, Santos A, Aquilino MS, Mylvaganam S, Urban K, Carlen PL. Cannabidiol Exerts Anticonvulsant Effects Alone and in Combination with Δ 9-THC through the 5-HT1A Receptor in the Neocortex of Mice. Cells 2024; 13:466. [PMID: 38534310 DOI: 10.3390/cells13060466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 02/15/2024] [Accepted: 02/27/2024] [Indexed: 03/28/2024] Open
Abstract
Cannabinoids have shown potential in drug-resistant epilepsy treatment; however, we lack knowledge on which cannabinoid(s) to use, dosing, and their pharmacological targets. This study investigated (i) the anticonvulsant effect of Cannabidiol (CBD) alone and (ii) in combination with Delta-9 Tetrahydrocannabinol (Δ9-THC), as well as (iii) the serotonin (5-HT)1A receptor's role in CBD's mechanism of action. Seizure activity, induced by 4-aminopyridine, was measured by extracellular field recordings in cortex layer 2/3 of mouse brain slices. The anticonvulsant effect of 10, 30, and 100 µM CBD alone and combined with Δ9-THC was evaluated. To examine CBD's mechanism of action, slices were pre-treated with a 5-HT1A receptor antagonist before CBD's effect was evaluated. An amount of ≥30 µM CBD alone exerted significant anticonvulsant effects while 10 µM CBD did not. However, 10 µM CBD combined with low-dose Δ9-THC (20:3 ratio) displayed significantly greater anticonvulsant effects than either phytocannabinoid alone. Furthermore, blocking 5-HT1A receptors before CBD application significantly abolished CBD's effects. Thus, our results demonstrate the efficacy of low-dose CBD and Δ9-THC combined and that CBD exerts its effects, at least in part, through 5-HT1A receptors. These results could address drug-resistance while providing insight into CBD's mechanism of action, laying the groundwork for further testing of cannabinoids as anticonvulsants.
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Affiliation(s)
- Yasaman Javadzadeh
- Krembil Research Institute, University Health Network, Toronto, ON M5S 0T8, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Alexandra Santos
- Krembil Research Institute, University Health Network, Toronto, ON M5S 0T8, Canada
| | - Mark S Aquilino
- Krembil Research Institute, University Health Network, Toronto, ON M5S 0T8, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Shanthini Mylvaganam
- Krembil Research Institute, University Health Network, Toronto, ON M5S 0T8, Canada
| | | | - Peter L Carlen
- Krembil Research Institute, University Health Network, Toronto, ON M5S 0T8, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 1A1, Canada
- Department of Medicine (Neurology), University Health Network, Toronto, ON M5G 2C4, Canada
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5
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Kollipara R, Langille E, Tobin C, French CR. Phytocannabinoids Reduce Seizures in Larval Zebrafish and Affect Endocannabinoid Gene Expression. Biomolecules 2023; 13:1398. [PMID: 37759798 PMCID: PMC10526363 DOI: 10.3390/biom13091398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/31/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
Cannabis has demonstrated anticonvulsant properties, and about thirty percent of epileptic patients do not have satisfactory seizure management with standard treatment and could potentially benefit from cannabis-based intervention. Here, we report the use of cannabinoids to treat pentylenetetrazol (PTZ)-induced convulsions in a zebrafish model, their effect on gene expression, and a simple assay for assessing their uptake in zebrafish tissues. Using an optimized behavioral assay, we show that cannabidiol (CBD) and cannabichromene (CBC) and cannabinol (CBN) are effective at reducing seizures at low doses, with little evidence of sedation, and our novel HPLC assay indicates that CBC is effective with the lowest accumulation in larval tissues. All cannabinoids tested were effective at higher concentrations. Pharmacological manipulation of potential receptors demonstrates that Gpr55 partially mediates the anticonvulsant effects of CBD. Treatment of zebrafish larvae with endocannabinoids, such as 2-arachidonoylglycerol (2-AG) and anandamide (AEA), altered larvae movement, and the expression of genes that regulate their metabolism was affected by phytocannabinoid treatment, highlighting the possibility that changes to endocannabinoid levels may represent one facet of the anticonvulsant effect of phytocannabinoids.
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Affiliation(s)
- Roshni Kollipara
- Department of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL A1B 3V6, Canada; (R.K.); (C.T.)
| | - Evan Langille
- Department of Chemistry, Faculty of Science, Memorial University of Newfoundland, St. John’s, NL A1B 3X7, Canada;
| | - Cameron Tobin
- Department of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL A1B 3V6, Canada; (R.K.); (C.T.)
| | - Curtis R. French
- Department of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL A1B 3V6, Canada; (R.K.); (C.T.)
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Knap B, Nieoczym D, Kundap U, Kusio-Targonska K, Kukula-Koch W, Turski WA, Gawel K. Zebrafish as a robust preclinical platform for screening plant-derived drugs with anticonvulsant properties-a review. Front Mol Neurosci 2023; 16:1221665. [PMID: 37701853 PMCID: PMC10493295 DOI: 10.3389/fnmol.2023.1221665] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/25/2023] [Indexed: 09/14/2023] Open
Abstract
Traditionally, selected plant sources have been explored for medicines to treat convulsions. This continues today, especially in countries with low-income rates and poor medical systems. However, in the low-income countries, plant extracts and isolated drugs are in high demand due to their good safety profiles. Preclinical studies on animal models of seizures/epilepsy have revealed the anticonvulsant and/or antiepileptogenic properties of, at least some, herb preparations or plant metabolites. Still, there is a significant number of plants known in traditional medicine that exert anticonvulsant activity but have not been evaluated on animal models. Zebrafish is recognized as a suitable in vivo model of epilepsy research and is increasingly used as a screening platform. In this review, the results of selected preclinical studies are summarized to provide credible information for the future development of effective screening methods for plant-derived antiseizure/antiepileptic therapeutics using zebrafish models. We compared zebrafish vs. rodent data to show the translational value of the former in epilepsy research. We also surveyed caveats in methodology. Finally, we proposed a pipeline for screening new anticonvulsant plant-derived drugs in zebrafish ("from tank to bedside and back again").
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Affiliation(s)
- Bartosz Knap
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Lublin, Poland
| | - Dorota Nieoczym
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland
| | - Uday Kundap
- Canada East Spine Center, Saint John Regional Hospital, Horizon Health Center, Saint John, NB, Canada
| | - Kamila Kusio-Targonska
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Lublin, Poland
| | - Wirginia Kukula-Koch
- Department of Pharmacognosy with Medicinal Plants Garden, Medical University, Lublin, Poland
| | - Waldemar A. Turski
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Lublin, Poland
| | - Kinga Gawel
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Lublin, Poland
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7
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Aguiar AFL, Campos RMP, Isaac AR, Paes-Colli Y, Carvalho VM, Sampaio LS, de Melo Reis RA. Long-Term Treatment with Cannabidiol-Enriched Cannabis Extract Induces Synaptic Changes in the Adolescent Rat Hippocampus. Int J Mol Sci 2023; 24:11775. [PMID: 37511537 PMCID: PMC10380262 DOI: 10.3390/ijms241411775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
The endocannabinoid system (eCS) is widely distributed in mammalian tissues and it is classically formed by cannabinoid receptors, endogenous bioactive lipids and its synthesis and degradation enzymes. Due to the modulatory role of eCS in synaptic activity in the Central Nervous System (CNS), phytocannabinoids have been increasingly used for the treatment of neurological disorders, even though little is known in terms of the long-term effect of these treatments on CNS development, mainly in the timeframe that comprises childhood and adolescence. Furthermore, an increased number of clinical trials using full-spectrum Cannabis extracts has been seen, rather than the isolated form of phytocannabinoids, when exploring the therapeutical benefits of the Cannabis plant. Thus, this study aims to evaluate the effect of cannabidiol (CBD)-enriched Cannabis extract on synaptic components in the hippocampus of rats from adolescence to early adulthood (postnatal day 45 to 60). Oral treatment of healthy male Wistar rats with a CBD-enriched Cannabis extract (3 mg/kg/day CBD) during 15 days did not affect food intake and water balance. There was also no negative impact on locomotor behaviour and cognitive performance. However, the hippocampal protein levels of GluA1 and GFAP were reduced in animals treated with the extract, whilst PSD95 levels were increased, which suggests rearrangement of glutamatergic synapses and modulation of astrocytic features. Microglial complexity was reduced in CA1 and CA3 regions, but no alterations in their phagocytic activity have been identified by Iba-1 and LAMP2 co-localization. Collectively, our data suggest that CBD-enriched Cannabis treatment may be safe and well-tolerated in healthy subjects, besides acting as a neuroprotective agent against hippocampal alterations related to the pathogenesis of excitatory and astrogliosis-mediated disorders in CNS.
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Affiliation(s)
- Andrey F L Aguiar
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21941902, Brazil
| | - Raquel M P Campos
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21941902, Brazil
| | - Alinny R Isaac
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro 21941902, Brazil
| | - Yolanda Paes-Colli
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21941902, Brazil
| | - Virgínia M Carvalho
- Faculty of Pharmacy, Federal University of Rio de Janeiro, Rio de Janeiro 21941902, Brazil
| | - Luzia S Sampaio
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21941902, Brazil
| | - Ricardo A de Melo Reis
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21941902, Brazil
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8
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Hippocampal expression of the cannabinoid receptor type 1 in canine epilepsy. Sci Rep 2023; 13:3138. [PMID: 36823232 PMCID: PMC9950490 DOI: 10.1038/s41598-023-29868-3] [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: 03/22/2022] [Accepted: 02/11/2023] [Indexed: 02/25/2023] Open
Abstract
Canine drug-resistant epilepsy is a prevailing issue in veterinary neurology. Alternative or additional treatment with cannabinoids is showing promising results in seizure management. A crucial component of the endocannabinoid system, cannabinoid receptor type 1 (CB1R), is heavily involved in the control of neurotransmitter release. Knowledge of its distribution in the epileptic brain would serve a better understanding of disease pathology and application of cannabinoids in dogs with epilepsy. CB1R distribution was assessed in sub-regions of hippocampus of dogs with idiopathic epilepsy, structural epilepsy and without cerebral pathology. In dogs with idiopathic epilepsy, significantly decreased CB1R expression compared to control animals was observed in CA1. In dogs with structural epilepsy, a significant increase in CB1R signal intensity in comparison to controls was observed. CB1R expression was higher in the structural group as compared to the idiopathic. Double immunofluorescence showed co-localization between CB1R and an astrocytic marker in about 50% of cells, regardless of the diagnosis. In summary, CB1R expression in canine hippocampus undergoes modification by the epileptic process and the direction of this change depends on the etiology of the disease. The distinct disease-associated CB1R expression needs to be considered in new treatment development for dogs with epilepsy.
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9
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Del Pozo A, Barker-Haliski M. Cannabidiol reveals a disruptive strategy for 21st century epilepsy drug discovery. Exp Neurol 2023; 360:114288. [PMID: 36471511 PMCID: PMC9789191 DOI: 10.1016/j.expneurol.2022.114288] [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: 09/27/2022] [Revised: 11/11/2022] [Accepted: 11/25/2022] [Indexed: 11/27/2022]
Abstract
Over 30 antiseizure medicines (ASMs) have been uncovered in a diversity of preclinical seizure and epilepsy models, with several critical inflection points in the 20th century fundamentally transforming ASM discovery. This commentary aims to review the historical relevance of cannabidiol's (CBD; Epidiolex) approval for epilepsy in the context of other ASMs brought to market. Further, we highlight how CBD's approval may represent an inflection point for 21st century ASM discovery. CBD is one of the main phytocannabinoids of Cannabis sativa. Unlike its related phytocannabinoid, Δ9-tetrahydrocannabinol, CBD does not exert any euphorigenic, tolerance, or withdrawal effects at anticonvulsant doses. CBD also possess marked anti-inflammatory effects, offering the tantalizing potential of a new pharmacological approach in epilepsy. For decades, hints of the anticonvulsant profile of CBD had been suggested with a small handful of studies in rodent seizure models, yet difficulties in formulation, compounded by the social and regulatory pressures related to medical use of cannabis plant-derived agents constrained any clinical implementation. Nonetheless, CBD possesses a broad antiseizure profile in preclinical seizure and epilepsy models, but the transformative impact of CBD'-s approval came because of studies in a rodent model of the orphan disease Dravet syndrome (DS). DS is a pediatric developmental epileptic encephalopathy with high mortality, frequent spontaneous recurrent seizures, and marked resistance to conventional ASMs, such as phenytoin and carbamazepine. CBD was approved for DS by the US Food and Drug Administration in 2018 after convincing efficacy was established in randomized, placebo-controlled trials in children. Because of the clinical approval of CBD as a novel, cannabis plantderived ASM for DS, CBD has revealed a new strategy in ASM discovery to reignite 21st century therapeutic development for epilepsy. In this commentary, we review the major preclinical and clinical milestones of the late 20th century that made CBD, a compound historically subjected to regulatory restrictions, a key driver of a new discovery strategy for epilepsy in the 21st century.
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Affiliation(s)
- Aaron Del Pozo
- Department of Pharmacy, University of Washington, Seattle, WA 98195, United States of America
| | - Melissa Barker-Haliski
- Department of Pharmacy, University of Washington, Seattle, WA 98195, United States of America.
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Erridge S, Holvey C, Coomber R, Hoare J, Khan S, Platt MW, Rucker JJ, Weatherall MW, Beri S, Sodergren MH. Clinical Outcome Data of Children Treated with Cannabis-Based Medicinal Products for Treatment Resistant Epilepsy - Analysis from the UK Medical Cannabis Registry. Neuropediatrics 2023; 54:174-181. [PMID: 36539215 PMCID: PMC10166640 DOI: 10.1055/a-2002-2119] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND There is a paucity of high-quality evidence of the efficacy and safety of cannabis-based medicinal products in treatment of treatment-resistant epilepsy (TRE) in children. METHODS A case series of children (<18 years old) with TRE from the UK Medical Cannabis Registry was analyzed. Primary outcomes were ≥50% reduction in seizure frequency, changes in the Impact of Pediatric Epilepsy Score (IPES), and incidence of adverse events. RESULTS Thirty-five patients were included in the analysis. Patients were prescribed during their treatment with the following: CBD isolate oils (n = 19), CBD broad-spectrum oils (n = 17), and CBD/Δ9-THC combination therapy (n = 17). Twenty-three (65.7%) patients achieved a ≥50% reduction in seizure frequency. 94.1% (n = 16) of patients treated with CBD and Δ9-THC observed a ≥50% reduction in seizure frequency compared to 31.6% (n = 6) and 17.6% (n = 3) of patients treated with CBD isolates and broad-spectrum CBD products, respectively (p< 0.001). Twenty-six (74.3%) adverse events were reported by 16 patients (45.7%). The majority of these were mild (n = 12; 34.2%) and moderate (n = 10; 28.6%). CONCLUSION The results of this study demonstrate a positive signal of improved seizure frequency in children treated with Cannabis-based medicinal products (CBMPs) for TRE. Moreover, the results suggest that CBMPs are well-tolerated in the short term. The limitations mean causation cannot be determined in this open-label, case series.
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Affiliation(s)
- Simon Erridge
- Department of Surgery & Cancer, Imperial College London, London, United Kingdom.,Department of Medicine, Sapphire Medical Clinics, London, United Kingdom
| | - Carl Holvey
- Department of Medicine, Sapphire Medical Clinics, London, United Kingdom
| | - Ross Coomber
- Department of Medicine, Sapphire Medical Clinics, London, United Kingdom.,Department of Trauma & Orthopaedics, St Georges NHS Healthcare Trust, London, United Kingdom
| | - Jonathan Hoare
- Department of Surgery & Cancer, Imperial College London, London, United Kingdom.,Department of Medicine, Sapphire Medical Clinics, London, United Kingdom
| | - Shaheen Khan
- Department of Medicine, Sapphire Medical Clinics, London, United Kingdom.,Department of Palliative Medicine, Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Michael W Platt
- Department of Surgery & Cancer, Imperial College London, London, United Kingdom.,Department of Medicine, Sapphire Medical Clinics, London, United Kingdom
| | - James J Rucker
- Department of Medicine, Sapphire Medical Clinics, London, United Kingdom.,Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, London, United Kingdom.,Centre for Affective Disorders, South London & Maudsley NHS Foundation Trust, London, United Kingdom
| | - Mark W Weatherall
- Department of Medicine, Sapphire Medical Clinics, London, United Kingdom.,Department of Neurology, Buckinghamshire Healthcare NHS Trust, Amersham, United Kingdom
| | - Sushil Beri
- Department of Surgery & Cancer, Imperial College London, London, United Kingdom.,Department of Medicine, Sapphire Medical Clinics, London, United Kingdom
| | - Mikael H Sodergren
- Department of Surgery & Cancer, Imperial College London, London, United Kingdom.,Department of Medicine, Sapphire Medical Clinics, London, United Kingdom
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Anderson LL, Bahceci DA, Hawkins NA, Everett-Morgan D, Banister SD, Kearney JA, Arnold JC. Heterozygous deletion of Gpr55 does not affect a hyperthermia-induced seizure, spontaneous seizures or survival in the Scn1a+/- mouse model of Dravet syndrome. PLoS One 2023; 18:e0280842. [PMID: 36701411 PMCID: PMC9879440 DOI: 10.1371/journal.pone.0280842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
A purified preparation of cannabidiol (CBD), a cannabis constituent, has been approved for the treatment of intractable childhood epilepsies such as Dravet syndrome. Extensive pharmacological characterization of CBD shows activity at numerous molecular targets but its anticonvulsant mechanism(s) of action is yet to be delineated. Many suggest that the anticonvulsant action of CBD is the result of G protein-coupled receptor 55 (GPR55) inhibition. Here we assessed whether Gpr55 contributes to the strain-dependent seizure phenotypes of the Scn1a+/- mouse model of Dravet syndrome. The Scn1a+/- mice on a 129S6/SvEvTac (129) genetic background have no overt phenotype, while those on a [129 x C57BL/6J] F1 background exhibit a severe phenotype that includes hyperthermia-induced seizures, spontaneous seizures and reduced survival. We observed greater Gpr55 transcript expression in the cortex and hippocampus of mice on the seizure-susceptible F1 background compared to those on the seizure-resistant 129 genetic background, suggesting that Gpr55 might be a genetic modifier of Scn1a+/- mice. We examined the effect of heterozygous genetic deletion of Gpr55 and pharmacological inhibition of GPR55 on the seizure phenotypes of F1.Scn1a+/- mice. Heterozygous Gpr55 deletion and inhibition of GPR55 with CID2921524 did not affect the temperature threshold of a thermally-induced seizure in F1.Scn1a+/- mice. Neither was there an effect of heterozygous Gpr55 deletion observed on spontaneous seizure frequency or survival of F1.Scn1a+/- mice. Our results suggest that GPR55 antagonism may not be a suitable anticonvulsant target for Dravet syndrome drug development programs, although future research is needed to provide more definitive conclusions.
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Affiliation(s)
- Lyndsey L. Anderson
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Medicine and Health, Discipline of Pharmacology, Sydney Pharmacy School, The University of Sydney, Sydney, NSW, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia
| | - Dilara A. Bahceci
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Medicine and Health, Discipline of Pharmacology, Sydney Pharmacy School, The University of Sydney, Sydney, NSW, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia
| | - Nicole A. Hawkins
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Evanston, IL, United States of America
| | - Declan Everett-Morgan
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia
| | - Samuel D. Banister
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Chemistry, The University of Sydney, Sydney, NSW, Australia
| | - Jennifer A. Kearney
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Evanston, IL, United States of America
| | - Jonathon C. Arnold
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Medicine and Health, Discipline of Pharmacology, Sydney Pharmacy School, The University of Sydney, Sydney, NSW, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia
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12
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Harman T, Udoh M, McElroy DL, Anderson LL, Kevin RC, Banister SD, Ametovski A, Markham J, Bladen C, Doohan PT, Greba Q, Laprairie RB, Snutch TP, McGregor IS, Howland JG, Arnold JC. MEPIRAPIM-derived synthetic cannabinoids inhibit T-type calcium channels with divergent effects on seizures in rodent models of epilepsy. Front Physiol 2023; 14:1086243. [PMID: 37082241 PMCID: PMC10110893 DOI: 10.3389/fphys.2023.1086243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 03/17/2023] [Indexed: 04/22/2023] Open
Abstract
Background: T-type Ca2+ channels (Cav3) represent emerging therapeutic targets for a range of neurological disorders, including epilepsy and pain. To aid the development and optimisation of new therapeutics, there is a need to identify novel chemical entities which act at these ion channels. A number of synthetic cannabinoid receptor agonists (SCRAs) have been found to exhibit activity at T-type channels, suggesting that cannabinoids may provide convenient chemical scaffolds on which to design novel Cav3 inhibitors. However, activity at cannabinoid type 1 (CB1) receptors can be problematic because of central and peripheral toxicities associated with potent SCRAs. The putative SCRA MEPIRAPIM and its analogues were recently identified as Cav3 inhibitors with only minimal activity at CB1 receptors, opening the possibility that this scaffold may be exploited to develop novel, selective Cav3 inhibitors. Here we present the pharmacological characterisation of SB2193 and SB2193F, two novel Cav3 inhibitors derived from MEPIRAPIM. Methods: The potency of SB2193 and SB2193F was evaluated in vitro using a fluorometric Ca2+ flux assay and confirmed using whole-cell patch-clamp electrophysiology. In silico docking to the cryo-EM structure of Cav3.1 was also performed to elucidate structural insights into T-type channel inhibition. Next, in vivo pharmacokinetic parameters in mouse brain and plasma were determined using liquid chromatography-mass spectroscopy. Finally, anticonvulsant activity was assayed in established genetic and electrically-induced rodent seizure models. Results: Both MEPIRAPIM derivatives produced potent inhibition of Cav3 channels and were brain penetrant, with SB2193 exhibiting a brain/plasma ratio of 2.7. SB2193 was further examined in mouse seizure models where it acutely protected against 6 Hz-induced seizures. However, SB2193 did not reduce spontaneous seizures in the Scn1a +/- mouse model of Dravet syndrome, nor absence seizures in the Genetic Absence Epilepsy Rat from Strasbourg (GAERS). Surprisingly, SB2193 appeared to increase the incidence and duration of spike-and-wave discharges in GAERS animals over a 4 h recording period. Conclusion: These results show that MEPIRAPIM analogues provide novel chemical scaffolds to advance Cav3 inhibitors against certain seizure types.
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Affiliation(s)
- Thomas Harman
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Michael Udoh
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Dan L. McElroy
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Lyndsey L. Anderson
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Richard C. Kevin
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Samuel D. Banister
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Adam Ametovski
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Jack Markham
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Chris Bladen
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | - Peter T. Doohan
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Quentin Greba
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Robert B. Laprairie
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Terrance P. Snutch
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Iain S. McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - John G. Howland
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jonathon C. Arnold
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
- *Correspondence: Jonathon C. Arnold,
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13
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Zavala-Tecuapetla C, Luna-Munguia H, López-Meraz ML, Cuellar-Herrera M. Advances and Challenges of Cannabidiol as an Anti-Seizure Strategy: Preclinical Evidence. Int J Mol Sci 2022; 23:ijms232416181. [PMID: 36555823 PMCID: PMC9783044 DOI: 10.3390/ijms232416181] [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: 10/29/2022] [Revised: 11/24/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022] Open
Abstract
The use of Cannabis for medicinal purposes has been documented since ancient times, where one of its principal cannabinoids extracted from Cannabis sativa, cannabidiol (CBD), has emerged over the last few years as a promising molecule with anti-seizure potential. Here, we present an overview of recent literature pointing out CBD's pharmacological profile (solubility, metabolism, drug-drug interactions, etc.,), CBD's interactions with multiple molecular targets as well as advances in preclinical research concerning its anti-seizure effect on both acute seizure models and chronic models of epilepsy. We also highlight the recent attention that has been given to other natural cannabinoids and to synthetic derivatives of CBD as possible compounds with therapeutic anti-seizure potential. All the scientific research reviewed here encourages to continue to investigate the probable therapeutic efficacy of CBD and its related compounds not only in epilepsy but also and specially in drug-resistant epilepsy, since there is a dire need for new and effective drugs to treat this disease.
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Affiliation(s)
- Cecilia Zavala-Tecuapetla
- Laboratory of Physiology of Reticular Formation, National Institute of Neurology and Neurosurgery, Insurgentes Sur 3877, La Fama, Mexico City 14269, Mexico
- Correspondence:
| | - Hiram Luna-Munguia
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, Queretaro 76230, Mexico
| | - María-Leonor López-Meraz
- Instituto de Investigaciones Cerebrales, Universidad Veracruzana, Luis Castelazo Ayala s/n, Col. Industrial Ánimas, Xalapa 91190, Mexico
| | - Manola Cuellar-Herrera
- Epilepsy Clinic, Hospital General de México Dr. Eduardo Liceaga, Dr. Balmis 148, Doctores, Mexico City 06720, Mexico
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14
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Colvin EK, Hudson AL, Anderson LL, Kumar RP, McGregor IS, Howell VM, Arnold JC. An Examination of the Anti-Cancer Properties of Plant Cannabinoids in Preclinical Models of Mesothelioma. Cancers (Basel) 2022; 14:cancers14153813. [PMID: 35954477 PMCID: PMC9367527 DOI: 10.3390/cancers14153813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/14/2022] [Accepted: 08/01/2022] [Indexed: 02/06/2023] Open
Abstract
Simple Summary Mesothelioma is a deadly disease with few treatment options. Phytocannabinoids derived from the cannabis plant are garnering interest for their anti-cancer properties, however very little is known about their effects in mesothelioma. We aimed to assess whether phytocannabinoids have anti-cancer effects in mesothelioma and potential modes of action. We showed that several phytocannabinoids inhibited growth of mesothelioma cells, with two phytocannabinoids, cannabidiol (CBD) and cannabigerol (CBG), being the most potent. CBD and CBG also inhibited mesothelioma cell migration and invasion. Gene expression analysis highlighted signalling pathways that play a role in how CBD and CBG may exert their anti-cancer effects. CBD and CBG were unable to increase survival in a rat model of mesothelioma but this may be due to limitations in the drug delivery method. Abstract Mesothelioma is an aggressive cancer with limited treatment options and a poor prognosis. Phytocannabinoids possess anti-tumour and palliative properties in multiple cancers, however their effects in mesothelioma are unknown. We investigated the anti-cancer effects and potential mechanisms of action for several phytocannabinoids in mesothelioma cell lines. A panel of 13 phytocannabinoids inhibited growth of human (MSTO and H2452) and rat (II-45) mesothelioma cells in vitro, and cannabidiol (CBD) and cannabigerol (CBG) were the most potent compounds. Treatment with CBD or CBG resulted in G0/G1 arrest, delayed entry into S phase and induced apoptosis. CBD and CBG also significantly reduced mesothelioma cell migration and invasion. These effects were supported by changes in the expression of genes associated with the cell cycle, proliferation, and cell movement following CBD or CBG treatment. Gene expression levels of CNR1, GPR55, and 5HT1A also increased with CBD or CBG treatment. However, treatment with CBD or CBG in a syngeneic orthotopic rat mesothelioma model was unable to increase survival. Our data show that cannabinoids have anti-cancer effects on mesothelioma cells in vitro and alternatives of drug delivery may be needed to enhance their effects in vivo.
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Affiliation(s)
- Emily K. Colvin
- Bill Walsh Translational Cancer Research Laboratory, Kolling Institute, St Leonards 2065, Australia
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney 2006, Australia
| | - Amanda L. Hudson
- Bill Walsh Translational Cancer Research Laboratory, Kolling Institute, St Leonards 2065, Australia
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney 2006, Australia
- Correspondence: (A.L.H.); (J.C.A.); Tel.: +61-2-9926-4722 (A.L.H.); +61-2-9351-0812 (J.C.A.)
| | - Lyndsey L. Anderson
- Lambert Initiative for Cannabinoid Therapeutics, University of Sydney, Sydney 2050, Australia
- Department of Pharmacology, Sydney Pharmacy School, University of Sydney, Sydney 2006, Australia
- Brain and Mind Centre, University of Sydney, Sydney 2050, Australia
| | - Ramyashree Prasanna Kumar
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia
| | - Iain S. McGregor
- Lambert Initiative for Cannabinoid Therapeutics, University of Sydney, Sydney 2050, Australia
- Brain and Mind Centre, University of Sydney, Sydney 2050, Australia
| | - Viive M. Howell
- Bill Walsh Translational Cancer Research Laboratory, Kolling Institute, St Leonards 2065, Australia
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney 2006, Australia
| | - Jonathon C. Arnold
- Lambert Initiative for Cannabinoid Therapeutics, University of Sydney, Sydney 2050, Australia
- Department of Pharmacology, Sydney Pharmacy School, University of Sydney, Sydney 2006, Australia
- Brain and Mind Centre, University of Sydney, Sydney 2050, Australia
- Correspondence: (A.L.H.); (J.C.A.); Tel.: +61-2-9926-4722 (A.L.H.); +61-2-9351-0812 (J.C.A.)
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15
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MacPhail SL, Bedoya-Pérez MA, Cohen R, Kotsirilos V, McGregor IS, Cairns EA. Medicinal Cannabis Prescribing in Australia: An Analysis of Trends Over the First Five Years. Front Pharmacol 2022; 13:885655. [PMID: 35620292 PMCID: PMC9127064 DOI: 10.3389/fphar.2022.885655] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 03/31/2022] [Indexed: 11/13/2022] Open
Abstract
A regulatory framework allowing legal access to medicinal cannabis (MC) products has operated in Australia since November 2016. MC prescribing by healthcare practitioners (HCPs) is primarily conducted through the Special Access Scheme - Category B (SAS-B) pathway, through which prescribers apply to the Therapeutic Goods Administration (TGA–the federal regulator) for approval to prescribe a category of product to an individual patient suffering from a specific indication. The dataset collected by the TGA provides a unique opportunity to examine MC prescribing trends over time in the Australian population. Here we analysed this TGA SAS-B dataset since inception with respect to age, gender, product type (e.g., oil, flower, etc.), CBD content, indication treated, and prescriber location. Results are presented descriptively as well as being analysed using non-linear regression models. Relationship between variables were explored via correspondence analyses. Indications were classified with reference to the International Statistical Classification of Diseases and Related Health Problems (10th Revision). As of 31 August 2021, a total of 159,665 SAS-B approvals had been issued for MC products, 82.4% of were since January 2020. Leading indications for approvals were for pain, anxiety, and sleep disorders. Oil products were the most popular product type, while CBD-dominant products (≥98% CBD) accounted for 25.1% of total approvals. Approvals for flower products increased markedly during 2020–2021, as did approvals involving younger age groups (18–31 years old), male patients, and non-CBD dominant products. A disproportionate number of SAS-B MC applications (around 50%) came from HCPs in the state of Queensland. Associations between patient gender and age and/or indication with product type were found. For example, approvals for oil products were commonly associated with approvals for pain. While, overall prescribing increased dramatically over the last 2 years of analysis, stabilization of approval numbers is evident for some indications, such as pain. Current prescribing practices do not always reflect provided TGA guidance documents for MC prescribing. While acknowledging some limitations around the SAS-B dataset, it provides a unique and valuable resource with which to better understand current prescribing practices and utilisation of MC products within Australia.
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Affiliation(s)
- Sara L MacPhail
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia.,School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - Miguel A Bedoya-Pérez
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia.,School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - Rhys Cohen
- School of Social Sciences, Department of Sociology, Macquarie University, Sydney, NSW, Australia.,Cannabis Consulting Australia, Sydney, NSW, Australia
| | - Vicki Kotsirilos
- NICM Health Research Institute, Western Sydney University, Sydney, NSW, Australia
| | - Iain S McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia.,School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - Elizabeth A Cairns
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia.,School of Psychology, The University of Sydney, Sydney, NSW, Australia
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16
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Anderson LL, Doohan PT, Hawkins NA, Bahceci D, Thakur GA, Kearney JA, Arnold JC, Arnold JC. The endocannabinoid system impacts seizures in a mouse model of Dravet syndrome. Neuropharmacology 2022; 205:108897. [PMID: 34822817 PMCID: PMC9514665 DOI: 10.1016/j.neuropharm.2021.108897] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/07/2021] [Accepted: 11/20/2021] [Indexed: 10/19/2022]
Abstract
Dravet syndrome is a catastrophic childhood epilepsy with multiple seizure types that are refractory to treatment. The endocannabinoid system regulates neuronal excitability so a deficit in endocannabinoid signaling could lead to hyperexcitability and seizures. Thus, we sought to determine whether a deficiency in the endocannabinoid system might contribute to seizure phenotypes in a mouse model of Dravet syndrome and whether enhancing endocannabinoid tone is anticonvulsant. Scn1a+/- mice model the clinical features of Dravet syndrome: hyperthermia-induced seizures, spontaneous seizures and reduced survival. We examined whether Scn1a+/- mice exhibit deficits in the endocannabinoid system by measuring brain cannabinoid receptor expression and endocannabinoid concentrations. Next, we determined whether pharmacologically enhanced endocannabinoid tone was anticonvulsant in Scn1a+/- mice. We used GAT229, a positive allosteric modulator of the cannabinoid (CB1) receptor, and ABX-1431, a compound that inhibits the degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG). The Scn1a+/- phenotype is strain-dependent with mice on a 129S6/SvEvTac (129) genetic background having no overt phenotype and those on an F1 (129S6/SvEvTac x C57BL/6J) background exhibiting a severe epilepsy phenotype. We observed lower brain cannabinoid CB1 receptor expression in the seizure-susceptible F1 compared to seizure-resistant 129 strain, suggesting an endocannabinoid deficiency might contribute to seizure susceptibility. GAT229 and ABX-1431 were anticonvulsant against hyperthermia-induced seizures. However, subchronic ABX1431 treatment increased spontaneous seizure frequency despite reducing seizure severity. Cnr1 is a putative genetic modifier of epilepsy in the Scn1a+/- mouse model of Dravet syndrome. Compounds that increase endocannabinoid tone could be developed as novel treatments for Dravet syndrome.
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Affiliation(s)
- Lyndsey L. Anderson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, NSW 2050, Australia,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia,Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
| | - Peter T. Doohan
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, NSW 2050, Australia,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia,Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
| | - Nicole A. Hawkins
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Dilara Bahceci
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, NSW 2050, Australia,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia,Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
| | - Ganesh A. Thakur
- Department of Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, MA 02115, USA
| | - Jennifer A. Kearney
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Jonathon C. Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, NSW 2050, Australia,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia,Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
| | - Jonathon C Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, NSW 2050, Australia.
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17
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Shapiro L, Escayg A, Wong JC. Cannabidiol Increases Seizure Resistance and Improves Behavior in an Scn8a Mouse Model. Front Pharmacol 2022; 13:815950. [PMID: 35153788 PMCID: PMC8826257 DOI: 10.3389/fphar.2022.815950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/04/2022] [Indexed: 12/11/2022] Open
Abstract
Voltage-gated sodium channel genes are an important family of human epilepsy genes. De novo missense mutations in SCN8A (encoding Nav1.6) are associated with a spectrum of clinical presentation, including multiple seizure types, movement disorders, intellectual disability, and behavioral abnormalities such as autism. Patients with SCN8A mutations are often treated with multiple antiepileptic drugs, the most common being sodium channel blockers. Cannabidiol (CBD) has been included as a component of treatment regimens for some SCN8A patients; however, to date, there are no clinical trials that have evaluated the therapeutic potential of CBD in patients with SCN8A mutations. In the current manuscript, we demonstrated a dose-dependent increase in seizure resistance following CBD treatment in mice expressing the human SCN8A mutation R1620L (RL/+). We also found that CBD treatment improved social behavior and reduced hyperactivity in the RL/+ mutants. Our findings suggest that CBD may be beneficial in patients with SCN8A-associated disease.
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Affiliation(s)
- Lindsey Shapiro
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Jennifer C Wong
- Department of Human Genetics, Emory University, Atlanta, GA, United States
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18
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Anderson LL, Udoh M, Everett-Morgan D, Heblinski M, McGregor IS, Banister SD, Arnold JC. Olivetolic acid, a cannabinoid precursor in Cannabis sativa, but not CBGA methyl ester exhibits a modest anticonvulsant effect in a mouse model of Dravet syndrome. J Cannabis Res 2022; 4:2. [PMID: 34980287 PMCID: PMC8725448 DOI: 10.1186/s42238-021-00113-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 12/07/2021] [Indexed: 12/17/2022] Open
Abstract
Objective Cannabigerolic acid (CBGA), a precursor cannabinoid in Cannabis sativa, has recently been found to have anticonvulsant properties in the Scn1a+/- mouse model of Dravet syndrome. Poor brain penetration and chemical instability of CBGA limits its potential as an anticonvulsant therapy. Here, we examined whether CBGA methyl ester, a more stable analogue of CBGA, might have superior pharmacokinetic and anticonvulsant properties. In addition, we examined whether olivetolic acid, the biosynthetic precursor to CBGA with a truncated (des-geranyl) form, might possess minimum structural requirements for anticonvulsant activity. We also examined whether olivetolic acid and CBGA methyl ester retain activity at the epilepsy-relevant drug targets of CBGA: G-protein-coupled receptor 55 (GPR55) and T-type calcium channels. Methods The brain and plasma pharmacokinetic profiles of CBGA methyl ester and olivetolic acid were examined following 10 mg/kg intraperitoneal (i.p.) administration in mice (n = 4). The anticonvulsant potential of each was examined in male and female Scn1a+/- mice (n = 17–19) against hyperthermia-induced seizures (10–100 mg/kg, i.p.). CBGA methyl ester and olivetolic acid were also screened in vitro against T-type calcium channels and GPR55 using intracellular calcium and ERK phosphorylation assays, respectively. Results CBGA methyl ester exhibited relatively limited brain penetration (13%), although somewhat superior to that of 2% for CBGA. No anticonvulsant effects were observed against thermally induced seizures in Scn1a+/- mice. Olivetolic acid also showed poor brain penetration (1%) but had a modest anticonvulsant effect in Scn1a+/- mice increasing the thermally induced seizure temperature threshold by approximately 0.4°C at a dose of 100 mg/kg. Neither CBGA methyl ester nor olivetolic acid displayed pharmacological activity at GPR55 or T-type calcium channels. Conclusions Olivetolic acid displayed modest anticonvulsant activity against hyperthermia-induced seizures in the Scn1a+/- mouse model of Dravet syndrome despite poor brain penetration. The effect was, however, comparable to the known anticonvulsant cannabinoid cannabidiol in this model. Future studies could explore the anticonvulsant mechanism(s) of action of olivetolic acid and examine whether its anticonvulsant effect extends to other seizure types. Supplementary Information The online version contains supplementary material available at 10.1186/s42238-021-00113-w.
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Affiliation(s)
- Lyndsey L Anderson
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia.,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, 2006, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia
| | - Michael Udoh
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia.,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, 2006, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia
| | - Declan Everett-Morgan
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia
| | - Marika Heblinski
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia.,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, 2006, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia
| | - Iain S McGregor
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia.,School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Samuel D Banister
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia.,School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Jonathon C Arnold
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2050, Australia. .,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, 2006, Australia. .,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, 2050, Australia.
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19
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Caraballo R, Reyes G, Demirdjian G, Huaman M, Gutierrez R. Long-term use of cannabidiol-enriched medical cannabis in a prospective cohort of children with drug-resistant developmental and epileptic encephalopathy. Seizure 2022; 95:56-63. [PMID: 34999381 DOI: 10.1016/j.seizure.2022.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/21/2021] [Accepted: 01/02/2022] [Indexed: 01/29/2023] Open
Abstract
OBJECTIVE We report our findings regarding effectiveness, safety, and tolerability of cannabidiol (CBD)-enriched medical cannabis as add-on therapy in children with drug-resistant epileptic encephalopathies (DEEs) after a median follow-up of 20 months. METHODS A prospective cohort study was conducted to assess effectiveness, safety, and tolerability of CBD-enriched medical cannabis oil added to standard antiseizure medications in children with drug-resistant DEE seen at a single center. RESULTS Between October 2018 and March 2020, 59 patients were enrolled. Mean age at enrollment was 10.5 years (range, 2-17 years). Median treatment duration was 20 months (range, 12-32). Median age at first seizure was 8 months (range, 1 day - 10 years). At the end of follow-up, 78% of the children had a ≥ 50% decrease in seizure frequency and 47.5% had a > 75% decrease. Seven patients (11.9%) were seizure free. The number of seizures was reduced from a median of 305/month to 90/month, amounting to a mean reduction of 57% and a median reduction of 71% (p < 0.0001). Adverse effects were mostly mild or moderate. CBD was discontinued in 17 patients (28.8%) due to lack of response to treatment, increased seizure frequency, intolerance to the drug, or poor compliance. CONCLUSION In children with drug-resistant DEEs, long-term treatment of CBD-enriched medical cannabis as an adjuvant therapy to antiseizure therapy was found to be safe, well tolerated, and effective. Sustained reductions in seizure frequency and improvement of aspects of daily living were observed compared to our preliminary findings.
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Affiliation(s)
- Roberto Caraballo
- Department of Neurology, Hospital de Pediatría "Prof. Dr. Juan P Garrahan", Combate de los Pozos 1881, Buenos Aires CP 1245, Argentina.
| | - Gabriela Reyes
- Department of Neurology, Hospital de Pediatría "Prof. Dr. Juan P Garrahan", Combate de los Pozos 1881, Buenos Aires CP 1245, Argentina
| | - Graciela Demirdjian
- Health Technology Assessment Unit Coordinator, Hospital de Pediatría "Juan P. Garrahan", Buenos Aires, Argentina.
| | - Marina Huaman
- Department of Neurology, Hospital de Pediatría "Prof. Dr. Juan P Garrahan", Combate de los Pozos 1881, Buenos Aires CP 1245, Argentina.
| | - Robinson Gutierrez
- Department of Neurology, Hospital de Pediatría "Prof. Dr. Juan P Garrahan", Combate de los Pozos 1881, Buenos Aires CP 1245, Argentina
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20
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Cannabidiol-enriched medical cannabis as add-on therapy in children with treatment-resistant West syndrome: A study of eight patients. Seizure 2021; 92:238-243. [PMID: 34624613 DOI: 10.1016/j.seizure.2021.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/15/2021] [Accepted: 10/02/2021] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE Here we present a series of patients with WS that were refractory to antiseizure medications and the ketogenic diet and who were treated with cannabidiol-enriched cannabis oil (CBD) as add-on therapy analyzing efficacy, safety, and tolerability. MATERIAL AND METHODS Medical records of eight patients with WS treated with CBD at a ratio of cannabidiol:Δ-9-tetrahydrocannabinol (CBD:THC) of 25:1 seen between May 2020 and March 2021 were retrospectively analyzed. In all patients CBD was started as add-on therapy. RESULTS Eight patients (six female and two male) who received CBD for treatment-resistant WS were evaluated. Ages ranged from 16 to 22 months. The etiology was unknown in five and structural in three. Initial CBD dose was 2 mg/kg/day which was uptitrated to a median dose of 12 mg/kg/day (range, 2-25). Prior to CBD initiation, patients had a mean of 63 seizures per day (range, 31-79). After a follow-up of between 6 and 13 months, a 75-99% decrease in seizure frequency was observed in two patients, a 50-74% decrease in two, a less than 50% decrease in three, and no changes in seizure frequency were seen in the remaining patient. The index of EEG abnormalities improved between 20 and 80% in seven patients concurrently with the reduction in seizures. Adverse effects were mild and transient. Somnolence was observed in one patient, nausea and vomiting in one, and behavior disturbances and irritability in another patient. CONCLUSION This study evaluating the use of cannabidiol-enriched cannabis oil in children with WS showed that four (50%) of eight had a more than 50% seizure reduction with good tolerability.
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21
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Anderson LL, Heblinski M, Absalom NL, Hawkins NA, Bowen M, Benson MJ, Zhang F, Bahceci D, Doohan PT, Chebib M, McGregor IS, Kearney JA, Arnold JC. Cannabigerolic acid, a major biosynthetic precursor molecule in cannabis, exhibits divergent effects on seizures in mouse models of epilepsy. Br J Pharmacol 2021; 178:4826-4841. [PMID: 34384142 PMCID: PMC9292928 DOI: 10.1111/bph.15661] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/26/2021] [Accepted: 08/10/2021] [Indexed: 11/28/2022] Open
Abstract
Background and Purpose Cannabis has been used to treat epilepsy for millennia, with such use validated by regulatory approval of cannabidiol (CBD) for Dravet syndrome. Unregulated artisanal cannabis‐based products used to treat children with intractable epilepsies often contain relatively low doses of CBD but are enriched in other phytocannabinoids. This raises the possibility that other cannabis constituents might have anticonvulsant properties. Experimental Approach We used the Scn1a+/− mouse model of Dravet syndrome to investigate the cannabis plant for phytocannabinoids with anticonvulsant effects against hyperthermia‐induced seizures. The most promising, cannabigerolic acid (CBGA), was further examined against spontaneous seizures and survival in Scn1a+/− mice and in electroshock seizure models. Pharmacological effects of CBGA were surveyed across multiple drug targets. Key Results The initial screen identified three phytocannabinoids with novel anticonvulsant properties: CBGA, cannabidivarinic acid (CBDVA) and cannabigerovarinic acid (CBGVA). CBGA was most potent and potentiated the anticonvulsant effects of clobazam against hyperthermia‐induced and spontaneous seizures, and was anticonvulsant in the MES threshold test. However, CBGA was proconvulsant in the 6‐Hz threshold test and a high dose increased spontaneous seizure frequency in Scn1a+/− mice. CBGA was found to interact with numerous epilepsy‐relevant targets including GPR55, TRPV1 channels and GABAA receptors. Conclusion and Implications These results suggest that CBGA, CBDVA and CBGVA may contribute to the effects of cannabis‐based products in childhood epilepsy. Although these phytocannabinoids have anticonvulsant potential and could be lead compounds for drug development programmes, several liabilities would need to be overcome before CBD is superseded by another in this class.
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Affiliation(s)
- L L Anderson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - M Heblinski
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - N L Absalom
- School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - N A Hawkins
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - M Bowen
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,School of Psychology, Faculty of Science, The University of Sydney, Sydney, New South Wales, Australia
| | - M J Benson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,School of Psychology, Faculty of Science, The University of Sydney, Sydney, New South Wales, Australia
| | - F Zhang
- School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - D Bahceci
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - P T Doohan
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - M Chebib
- School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - I S McGregor
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,School of Psychology, Faculty of Science, The University of Sydney, Sydney, New South Wales, Australia
| | - J A Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - J C Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
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22
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Anderson LL, Etchart MG, Bahceci D, Golembiewski TA, Arnold JC. Cannabis constituents interact at the drug efflux pump BCRP to markedly increase plasma cannabidiolic acid concentrations. Sci Rep 2021; 11:14948. [PMID: 34294753 PMCID: PMC8298633 DOI: 10.1038/s41598-021-94212-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/25/2021] [Indexed: 12/19/2022] Open
Abstract
Cannabis is a complex mixture of hundreds of bioactive molecules. This provides the potential for pharmacological interactions between cannabis constituents, a phenomenon referred to as “the entourage effect” by the medicinal cannabis community. We hypothesize that pharmacokinetic interactions between cannabis constituents could substantially alter systemic cannabinoid concentrations. To address this hypothesis we compared pharmacokinetic parameters of cannabinoids administered orally in a cannabis extract to those administered as individual cannabinoids at equivalent doses in mice. Astonishingly, plasma cannabidiolic acid (CBDA) concentrations were 14-times higher following administration in the cannabis extract than when administered as a single molecule. In vitro transwell assays identified CBDA as a substrate of the drug efflux transporter breast cancer resistance protein (BCRP), and that cannabigerol and Δ9-tetrahydrocannabinol inhibited the BCRP-mediated transport of CBDA. Such a cannabinoid-cannabinoid interaction at BCRP transporters located in the intestine would inhibit efflux of CBDA, thus resulting in increased plasma concentrations. Our results suggest that cannabis extracts provide a natural vehicle to substantially enhance plasma CBDA concentrations. Moreover, CBDA might have a more significant contribution to the pharmacological effects of orally administered cannabis extracts than previously thought.
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Affiliation(s)
- Lyndsey L Anderson
- Brain and Mind Centre, Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia.,Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, 94 Mallett St, Camperdown, NSW, 2050, Australia
| | - Maia G Etchart
- Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, 94 Mallett St, Camperdown, NSW, 2050, Australia
| | - Dilara Bahceci
- Brain and Mind Centre, Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
| | - Taliesin A Golembiewski
- Brain and Mind Centre, Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
| | - Jonathon C Arnold
- Brain and Mind Centre, Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia. .,Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, 94 Mallett St, Camperdown, NSW, 2050, Australia.
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23
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Satpute Janve V, Anderson LL, Bahceci D, Hawkins NA, Kearney JA, Arnold JC. The Heat Sensing Trpv1 Receptor Is Not a Viable Anticonvulsant Drug Target in the Scn1a +/- Mouse Model of Dravet Syndrome. Front Pharmacol 2021; 12:675128. [PMID: 34079465 PMCID: PMC8165383 DOI: 10.3389/fphar.2021.675128] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/27/2021] [Indexed: 11/13/2022] Open
Abstract
Cannabidiol has been approved for the treatment of drug-resistant childhood epilepsies including Dravet syndrome (DS). Although the mechanism of anticonvulsant action of cannabidiol is unknown, emerging data suggests involvement of the transient receptor potential cation channel subfamily V member 1 (Trpv1). Pharmacological and genetic studies in conventional seizure models suggest Trpv1 is a novel anticonvulsant target. However, whether targeting Trpv1 is anticonvulsant in animal models of drug-resistant epilepsies is not known. Thus, we examined whether Trpv1 affects the epilepsy phenotype of the F1.Scn1a +/- mouse model of DS. We found that cortical Trpv1 mRNA expression was increased in seizure susceptible F1.Scn1a +/- mice with a hybrid genetic background compared to seizure resistant 129.Scn1a +/- mice isogenic on 129S6/SvEvTac background, suggesting Trpv1 could be a genetic modifier. Previous studies show functional loss of Trpv1 is anticonvulsant. However, Trpv1 selective antagonist SB-705498 did not affect hyperthermia-induced seizure threshold, frequency of spontaneous seizures or survival of F1.Scn1a +/- mice. Surprisingly, Trpv1 deletion had both pro- and anti-seizure effects. Trpv1 deletion did not affect hyperthermia-induced seizure temperature thresholds of F1.Scn1a +/- ; Trpv1 +/- at P14-16 but was proconvulsant at P18 as it reduced seizure temperature thresholds. Conversely, Trpv1 deletion did not alter the frequency of spontaneous seizures but reduced their severity. These results suggest that Trpv1 is a modest genetic modifier of spontaneous seizure severity in the F1.Scn1a +/- model of DS. However, the opposing pro- and anti-seizure effects of Trpv1 deletion and the lack of effects of Trpv1 inhibition suggest that Trpv1 is unlikely a viable anticonvulsant drug target in DS.
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Affiliation(s)
- Vaishali Satpute Janve
- Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, Sydney, NSW, Australia.,Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Lyndsey L Anderson
- Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, Sydney, NSW, Australia.,Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Dilara Bahceci
- Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, Sydney, NSW, Australia.,Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Nicole A Hawkins
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Jennifer A Kearney
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Jonathon C Arnold
- Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, Sydney, NSW, Australia.,Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
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24
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Martin LJ, Banister SD, Bowen MT. Understanding the complex pharmacology of cannabidiol: Mounting evidence suggests a common binding site with cholesterol. Pharmacol Res 2021; 166:105508. [PMID: 33610721 DOI: 10.1016/j.phrs.2021.105508] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/28/2021] [Accepted: 02/16/2021] [Indexed: 12/19/2022]
Abstract
Cannabidiol is claimed to bind to a large number of protein targets based on in vitro assays. This suggests opportunities for a wide range of therapeutic applications. On the other hand, the existence of phytochemical 'nuisance compounds' suggests some measure of caution - these compounds are capable of altering membrane biophysical properties and changing protein function without directly contacting a binding site. Like cannabidiol, cholesterol alters membrane properties, but it also binds directly to membrane proteins through abundant cholesterol recognition sites. We present the evidence that cannabidiol and cholesterol may bind to the same site on some proteins. As a starting point for further research, we also used blind docking to show that cannabidiol binds to a cholesterol binding site on the CB1 receptor. Elucidation of the mechanism(s) of action of cannabidiol will assist the prioritisation of in vitro hits across targets, improve the success rate of medicinal chemistry campaigns, and ultimately benefit patient populations by focusing resources on programs with the most translational potential.
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Affiliation(s)
- Lewis J Martin
- The University of Sydney, Brain and Mind Centre, The Lambert Initiative for Cannabinoid Therapeutics, Sydney, NSW, Australia; The University of Sydney, Brain and Mind Centre, Sydney, NSW, Australia; The University of Sydney, Faculty of Science, School of Psychology, NSW, Australia
| | - Samuel D Banister
- The University of Sydney, Brain and Mind Centre, The Lambert Initiative for Cannabinoid Therapeutics, Sydney, NSW, Australia; The University of Sydney, Brain and Mind Centre, Sydney, NSW, Australia
| | - Michael T Bowen
- The University of Sydney, Brain and Mind Centre, The Lambert Initiative for Cannabinoid Therapeutics, Sydney, NSW, Australia; The University of Sydney, Brain and Mind Centre, Sydney, NSW, Australia; The University of Sydney, Faculty of Science, School of Psychology, NSW, Australia.
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25
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Anderson LL, Ametovski A, Lin Luo J, Everett-Morgan D, McGregor IS, Banister SD, Arnold JC. Cannabichromene, Related Phytocannabinoids, and 5-Fluoro-cannabichromene Have Anticonvulsant Properties in a Mouse Model of Dravet Syndrome. ACS Chem Neurosci 2021; 12:330-339. [PMID: 33395525 DOI: 10.1021/acschemneuro.0c00677] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Cannabis-based products are increasingly being used to treat refractory childhood epilepsies such as Dravet syndrome. Cannabis contains at least 140 terpenophenolic compounds known as phytocannabinoids. These include the known anticonvulsant compound cannabidiol (CBD) and several molecules showing emergent anticonvulsant properties in animal models. Cannabichromene (CBC) is a phytocannabinoid frequently detected in artisanal cannabis oils used in the community by childhood epilepsy patients. Here we examined the brain and plasma pharmacokinetic profiles of CBC, cannabichromenic acid (CBCA), cannabichromevarin (CBCV), and cannabichromevarinic acid (CBCVA) following intraperitoneal administration in mice. The anticonvulsant potential of each was then tested against hyperthermia-induced seizures in the Scn1a+/- mouse model of Dravet syndrome. All phytocannabinoids within the CBC series were readily absorbed and showed substantial brain penetration (brain-plasma ratios ranging from 0.2 to 5.8). Anticonvulsant efficacy was evident with CBC, CBCA, and CBCVA, each significantly increasing the temperature threshold at which Scn1a+/- mice had a generalized tonic-clonic seizure. We synthesized a fluorinated derivative of CBC (5-fluoro-CBC), which showed improved brain penetration relative to the parent CBC molecule but not any greater anticonvulsant effect. Since CBC and derivatives are anticonvulsant in a model of intractable pediatric epilepsy, they may constitute part of the mechanism through which artisanal cannabis oils are anticonvulsant in patients.
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Affiliation(s)
- Lyndsey L. Anderson
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
| | - Adam Ametovski
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Jia Lin Luo
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Declan Everett-Morgan
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
| | - Iain S. McGregor
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Samuel D. Banister
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Jonathon C. Arnold
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia
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26
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Vega-García A, Feria-Romero I, García-Juárez A, Munguia-Madera AC, Montes-Aparicio AV, Zequeida-Muñoz E, Garcia-Albavera E, Orozco-Suárez S. Cannabinoids: A New Perspective on Epileptogenesis and Seizure Treatment in Early Life in Basic and Clinical Studies. Front Behav Neurosci 2021; 14:610484. [PMID: 33510627 PMCID: PMC7835327 DOI: 10.3389/fnbeh.2020.610484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 11/26/2020] [Indexed: 01/19/2023] Open
Abstract
Neural hyperexcitability in the event of damage during early life, such as hyperthermia, hypoxia, traumatic brain injury, status epilepticus, or a pre-existing neuroinflammatory condition, can promote the process of epileptogenesis, which is defined as the sequence of events that converts a normal circuit into a hyperexcitable circuit and represents the time that occurs between the damaging event and the development of spontaneous seizure activity or the establishment of epilepsy. Epilepsy is the most common neurological disease in the world, characterized by the presence of seizures recurring without apparent provocation. Cannabidiol (CBD), a phytocannabinoid derived from the subspecies Cannabis sativa (CS), is the most studied active ingredient and is currently studied as a therapeutic strategy: it is an anticonvulsant mainly used in children with catastrophic epileptic syndromes and has also been reported to have anti-inflammatory and antioxidant effects, supporting it as a therapeutic strategy with neuroprotective potential. However, the mechanisms by which CBD exerts these effects are not entirely known, and the few studies on acute and chronic models in immature animals have provided contradictory results. Thus, it is difficult to evaluate the therapeutic profile of CBD, as well as the involvement of the endocannabinoid system in epileptogenesis in the immature brain. Therefore, this review focuses on the collection of scientific data in animal models, as well as information from clinical studies on the effects of cannabinoids on epileptogenesis and their anticonvulsant and adverse effects in early life.
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Affiliation(s)
- Angélica Vega-García
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Iris Feria-Romero
- Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, "Dr. Bernardo Sepúlveda", Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, IMSS, Ciudad de México, Mexico
| | - Anais García-Juárez
- División de Ciencias Biológicas y Ambientales, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Guadalajara, Mexico
| | - Ana Ch Munguia-Madera
- Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, "Dr. Bernardo Sepúlveda", Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, IMSS, Ciudad de México, Mexico
| | - Alexia V Montes-Aparicio
- Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, "Dr. Bernardo Sepúlveda", Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, IMSS, Ciudad de México, Mexico
| | | | | | - Sandra Orozco-Suárez
- Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, "Dr. Bernardo Sepúlveda", Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, IMSS, Ciudad de México, Mexico
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27
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Anderson LL, Etchart MG, MacNair L, Land MH, Mosesova IA, Bonn-Miller MO, Arnold JC. In Vitro Screening of Three Commercial Cannabis-Based Products on ATP-Binding Cassette and Solute-Carrier Transporter Function. Cannabis Cannabinoid Res 2020; 7:304-317. [PMID: 33998860 DOI: 10.1089/can.2020.0053] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Introduction: Legalization of medicinal cannabis around the world has led to an increase in the use of commercial cannabis-based products in the community. These cannabis-based products are being used in combination with conventional drugs to treat a variety of health conditions. Moreover, recreational cannabis-based products may be used in combination with other drugs. In this setting, there is increased potential for drug-drug interactions (DDIs) involving commercial cannabis-based products. Since DDIs can lead to serious adverse events, drug regulatory bodies require that every investigational drug be evaluated for DDI potential at metabolic enzymes and transporters. However, this seldom occurs for cannabis-based products due to legislation in many jurisdictions allowing a direct pathway to market. This study aimed to examine the inhibitory potential of three commercially available cannabis-based products at human ATP-binding cassette (ABC) and solute-carrier (SLC) transporters. Materials and Methods: Three commercial cannabis-based products (Spectrum Yellow™, Tweed Argyle, and Spectrum Red™) that contain differing concentrations of cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC) were evaluated for DDI potential at 12 drug transporters. HEK293 cells or vesicles expressing human ABC transporters (ABCB1, ABCC2, ABCG2, or ABCB11) and SLC transporters (SLC22A1, SLC22A2, SLC22A6, SLC22A8, SLCO1B1, SLCO1B3, SLC47A1, and SLC47A2) were used to measure transporter function. Results: Spectrum Yellow and Tweed Argyle inhibited ABCG2 transporter function. The IC50 value of Spectrum Yellow based on CBD and Δ9-THC content was 4.5 μM for CBD and 0.20 μM for Δ9-THC, and the IC50 value of Tweed Argyle was 9.3 μM for CBD and 6.0 μM for Δ9-THC. Tweed Argyle also inhibited ABCB11 transporter function with an IC50 value of 11.9 μM for CBD and 7.7 μM for Δ9-THC. SLC22A6, SLC22A1, SLC22A2, SLCO1B1, and SLCO1B3 transporter functions were modestly inhibited by high concentrations of the cannabis-based products. The three cannabis-based products did not inhibit ABCB1, ABCC2, SLC47A1, SLC47A2, or SLC22A8 transporters. Discussion: Novel findings were that the cannabis-based products inhibited ABCB11, SLC22A6, SLC22A1, SLC22A2, SLCO1B1, and SLCO1B3 (although modestly in most instances). Spectrum Yellow and Tweed Argyle potently inhibited ABCG2, and future in vivo DDI studies could be conducted to assess whether cannabis products affect the pharmacokinetics of medications that are ABCG2 substrates.
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Affiliation(s)
- Lyndsey L Anderson
- Brain and Mind Centre, The University of Sydney, Sydney, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
| | - Maia G Etchart
- Brain and Mind Centre, The University of Sydney, Sydney, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, Australia
| | - Laura MacNair
- Canopy Growth Corporation, Smiths Falls, Ontario, Canada
| | - M Hunter Land
- Canopy Growth Corporation, Smiths Falls, Ontario, Canada
| | | | | | - Jonathon C Arnold
- Brain and Mind Centre, The University of Sydney, Sydney, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
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Benson MJ, Anderson LL, Low IK, Luo JL, Kevin RC, Zhou C, McGregor IS, Arnold JC. Evaluation of the Possible Anticonvulsant Effect of Δ 9-Tetrahydrocannabinolic Acid in Murine Seizure Models. Cannabis Cannabinoid Res 2020; 7:46-57. [PMID: 33998858 PMCID: PMC8864425 DOI: 10.1089/can.2020.0073] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Introduction: The cannabinoid Δ9-tetrahydrocannabinolic acid (Δ9-THCA) has long been suggested in review articles and anecdotal reports to be anticonvulsant; yet, there is scant evidence supporting this notion. The objective of this study was to interrogate the anticonvulsant potential of Δ9-THCA in various seizure models—the Scn1a+/− mouse model of Dravet syndrome, the 6-Hz model of psychomotor seizures and the maximal electroshock (MES) model of generalized tonic-clonic seizures. Materials and Methods: We examined the effect of acute Δ9-THCA treatment against hyperthermia-induced seizures, and subchronic treatment on spontaneous seizures and survival in the Scn1a+/− mice. We also studied the effect of acute Δ9-THCA treatment on the critical current thresholds in the 6-Hz and MES tests using outbred Swiss mice. Highly purified Δ9-THCA was used in the studies or a mixture of Δ9-THCA and Δ9-THC. Results: We observed mixed anticonvulsant and proconvulsant effects of Δ9-THCA across the seizure models. Highly pure Δ9-THCA did not affect hyperthermia-induced seizures in Scn1a+/− mice. A Δ9-THCA/Δ9-THC mixture was anticonvulsant in the 6-Hz threshold test, but purified Δ9-THCA and Δ9-THC had no effect. Conversely, both Δ9-THCA and Δ9-THC administered individually were proconvulsant in the MES threshold test but had no effect when administered as a Δ9-THCA/Δ9-THC mixture. The Δ9-THCA/Δ9-THC mixture, however, increased spontaneous seizure severity and increased mortality of Scn1a+/− mice. Discussion: The anticonvulsant profile of Δ9-THCA was variable depending on the seizure model used and presence of Δ9-THC. Because of the unstable nature of Δ9-THCA, further exploration of Δ9-THCA through formal anticonvulsant drug development is problematic without stabilization. Future studies may better focus on determining the mechanisms by which combined Δ9-THCA and Δ9-THC alters seizure thresholds, as this may uncover novel targets for the control of refractory partial seizures.
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Affiliation(s)
- Melissa J Benson
- Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Faculty of Science, School of Psychology, The University of Sydney, Sydney, New South Wales, Australia
| | - Lyndsey L Anderson
- Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Ivan K Low
- Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia
| | - Jia Lin Luo
- Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Faculty of Science, School of Psychology, The University of Sydney, Sydney, New South Wales, Australia
| | - Richard C Kevin
- Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Faculty of Science, School of Psychology, The University of Sydney, Sydney, New South Wales, Australia
| | - Cilla Zhou
- Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Iain S McGregor
- Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Faculty of Science, School of Psychology, The University of Sydney, Sydney, New South Wales, Australia
| | - Jonathon C Arnold
- Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
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29
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Anderson LL, Low IK, McGregor IS, Arnold JC. Interactions between cannabidiol and Δ 9 -tetrahydrocannabinol in modulating seizure susceptibility and survival in a mouse model of Dravet syndrome. Br J Pharmacol 2020; 177:4261-4274. [PMID: 32608111 DOI: 10.1111/bph.15181] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/28/2020] [Accepted: 06/24/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE Extracts from the cannabis plant can dramatically improve the health of children suffering from refractory epilepsies such as Dravet syndrome. These extracts typically contain cannabidiol (CBD), a phytocannabinoid with well-documented anticonvulsant effects, but may also contain Δ9 -tetrahydrocannabinol (Δ9 -THC). It is unclear whether the presence of Δ9 -THC modulates the anticonvulsant efficacy of CBD. Here, we utilized the Scn1a+/- mouse model of Dravet syndrome to examine this question. EXPERIMENTAL APPROACH Scn1a+/- mice recapitulate core features of Dravet syndrome, including hyperthermia-induced seizures, early onset spontaneous seizures and sudden death. We assessed the effects on CBD and Δ9 -THC alone, and in combination on hyperthermia-induced seizures, spontaneous seizures and premature mortality. KEY RESULTS Administered alone, CBD (100 mg·kg-1 i.p.) was anticonvulsant against hyperthermia-induced seizures as were low (0.1 and 0.3 mg·kg-1 i.p.) but not higher doses of Δ9 -THC. A subthreshold dose of CBD (12 mg·kg-1 ) enhanced the anticonvulsant effects of Δ9 -THC (0.1 mg·kg-1 ). Sub-chronic oral administration of Δ9 -THC or CBD alone did not affect spontaneous seizure frequency or mortality while, surprisingly, their co-administration increased the severity of spontaneous seizures and overall mortality. CONCLUSION AND IMPLICATIONS Low doses of Δ9 -THC are anticonvulsant against hyperthermia-induced seizures in Scn1a+/- mice, effects that are enhanced by a sub-anticonvulsant dose of CBD. However, proconvulsant effects and increased premature mortality are observed when CBD and Δ9 -THC are sub-chronically dosed in combination. The possible explanations and implications of this are discussed.
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Affiliation(s)
- Lyndsey L Anderson
- Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia
| | - Ivan K Low
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia
| | - Iain S McGregor
- Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,School of Psychology, Faculty of Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Jonathon C Arnold
- Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia
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