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Morris G, Walder K, Kloiber S, Amminger P, Berk M, Bortolasci CC, Maes M, Puri BK, Carvalho AF. The endocannabinoidome in neuropsychiatry: Opportunities and potential risks. Pharmacol Res 2021; 170:105729. [PMID: 34119623 DOI: 10.1016/j.phrs.2021.105729] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/31/2021] [Accepted: 06/09/2021] [Indexed: 02/08/2023]
Abstract
The endocannabinoid system (ECS) comprises two cognate endocannabinoid receptors referred to as CB1R and CB2R. ECS dysregulation is apparent in neurodegenerative/neuro-psychiatric disorders including but not limited to schizophrenia, major depressive disorder and potentially bipolar disorder. The aim of this paper is to review mechanisms whereby both receptors may interact with neuro-immune and neuro-oxidative pathways, which play a pathophysiological role in these disorders. CB1R is located in the presynaptic terminals of GABAergic, glutamatergic, cholinergic, noradrenergic and serotonergic neurons where it regulates the retrograde suppression of neurotransmission. CB1R plays a key role in long-term depression, and, to a lesser extent, long-term potentiation, thereby modulating synaptic transmission and mediating learning and memory. Optimal CB1R activity plays an essential neuroprotective role by providing a defense against the development of glutamate-mediated excitotoxicity, which is achieved, at least in part, by impeding AMPA-mediated increase in intracellular calcium overload and oxidative stress. Moreover, CB1R activity enables optimal neuron-glial communication and the function of the neurovascular unit. CB2R receptors are detected in peripheral immune cells and also in central nervous system regions including the striatum, basal ganglia, frontal cortex, hippocampus, amygdala as well as the ventral tegmental area. CB2R upregulation inhibits the presynaptic release of glutamate in several brain regions. CB2R activation also decreases neuroinflammation partly by mediating the transition from a predominantly neurotoxic "M1" microglial phenotype to a more neuroprotective "M2" phenotype. CB1R and CB2R are thus novel drug targets for the treatment of neuro-immune and neuro-oxidative disorders including schizophrenia and affective disorders.
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Affiliation(s)
- Gerwyn Morris
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Ken Walder
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Deakin University, Centre for Molecular and Medical Research, School of Medicine, Geelong, Australia
| | - Stefan Kloiber
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 33 Ursula Franklin Street, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Paul Amminger
- Orygen, Parkville, Victoria, Australia; Centre for Youth Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Michael Berk
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Orygen, The National Centre of Excellence in Youth Mental Health, Centre for Youth Mental Health, Florey Institute for Neuroscience and Mental Health and the Department of Psychiatry, The University of Melbourne, Melbourne, Australia
| | - Chiara C Bortolasci
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Michael Maes
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Department of Psychiatry, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Bangkok, Thailand; Department of Psychiatry, Medical University of Plovdiv, Plovdiv, Bulgaria
| | | | - Andre F Carvalho
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia.
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Bobrich M, Schwarz R, Ramer R, Borchert P, Hinz B. A simple LC-MS/MS method for the simultaneous quantification of endocannabinoids in biological samples. J Chromatogr B Analyt Technol Biomed Life Sci 2020; 1161:122371. [DOI: 10.1016/j.jchromb.2020.122371] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 06/30/2020] [Accepted: 09/02/2020] [Indexed: 01/15/2023]
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YÜCEL E, AKTUNA Z, KESKİL İ. Effects of Endocannabinoids in Pentilenetetrazole Induced Seizures In Mice. ACTA MEDICA ALANYA 2020. [DOI: 10.30565/medalanya.690410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Ramer R, Schwarz R, Hinz B. Modulation of the Endocannabinoid System as a Potential Anticancer Strategy. Front Pharmacol 2019; 10:430. [PMID: 31143113 PMCID: PMC6520667 DOI: 10.3389/fphar.2019.00430] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 04/04/2019] [Indexed: 12/16/2022] Open
Abstract
Currently, the involvement of the endocannabinoid system in cancer development and possible options for a cancer-regressive effect of cannabinoids are controversially discussed. In recent decades, a number of preclinical studies have shown that cannabinoids have an anticarcinogenic potential. Therefore, especially against the background of several legal simplifications with regard to the clinical application of cannabinoid-based drugs, an extended basic knowledge about the complex network of the individual components of the endocannabinoid system is required. The canonical endocannabinoid system consists of the endocannabinoids N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol as well as the Gi/o protein-coupled transmembrane cannabinoid receptors CB1 and CB2. As a result of extensive studies on the broader effect of these factors, other fatty acid derivatives, transmembrane and intracellular receptors, enzymes and lipid transporters have been identified that contribute to the effect of endocannabinoids when defined in the broad sense as “extended endocannabinoid system.” Among these additional components, the endocannabinoid-degrading enzymes fatty acid amide hydrolase and monoacylglycerol lipase, lipid transport proteins of the fatty acid-binding protein family, additional cannabinoid-activated G protein-coupled receptors such as GPR55, members of the transient receptor family, and peroxisome proliferator-activated receptors were identified as targets for possible strategies to combat cancer progression. Other endocannabinoid-related fatty acids such as 2-arachidonoyl glyceryl ether, O-arachidonoylethanolamine, N-arachidonoyldopamine and oleic acid amide showed an effect via cannabinoid receptors, while other compounds such as endocannabinoid-like substances exert a permissive action on endocannabinoid effects and act via alternative intracellular target structures. This review gives an overview of the modulation of the extended endocannabinoid system using the example of anticancer cannabinoid effects, which have been described in detail in preclinical studies.
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Affiliation(s)
- Robert Ramer
- Institute of Pharmacology and Toxicology, Rostock University Medical Center, Rostock, Germany
| | - Rico Schwarz
- Institute of Pharmacology and Toxicology, Rostock University Medical Center, Rostock, Germany
| | - Burkhard Hinz
- Institute of Pharmacology and Toxicology, Rostock University Medical Center, Rostock, Germany
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Schwarz R, Ramer R, Hinz B. Targeting the endocannabinoid system as a potential anticancer approach. Drug Metab Rev 2018; 50:26-53. [PMID: 29390896 DOI: 10.1080/03602532.2018.1428344] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The endocannabinoid system is currently under intense investigation due to the therapeutic potential of cannabinoid-based drugs as treatment options for a broad variety of diseases including cancer. Besides the canonical endocannabinoid system that includes the cannabinoid receptors CB1 and CB2 and the endocannabinoids N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol, recent investigations suggest that other fatty acid derivatives, receptors, enzymes, and lipid transporters likewise orchestrate this system as components of the endocannabinoid system when defined as an extended signaling network. As such, fatty acids acting at cannabinoid receptors (e.g. 2-arachidonoyl glyceryl ether [noladin ether], N-arachidonoyldopamine) as well as endocannabinoid-like substances that do not elicit cannabinoid receptor activation (e.g. N-palmitoylethanolamine, N-oleoylethanolamine) have raised interest as anticancerogenic substances. Furthermore, the endocannabinoid-degrading enzymes fatty acid amide hydrolase and monoacylglycerol lipase, lipid transport proteins of the fatty acid binding protein family, additional cannabinoid-activated G protein-coupled receptors, members of the transient receptor potential family as well as peroxisome proliferator-activated receptors have been considered as targets of antitumoral cannabinoid activity. Therefore, this review focused on the antitumorigenic effects induced upon modulation of this extended endocannabinoid network.
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Affiliation(s)
- Rico Schwarz
- a Institute of Pharmacology and Toxicology , Rostock University Medical Center , Rostock , Germany
| | - Robert Ramer
- a Institute of Pharmacology and Toxicology , Rostock University Medical Center , Rostock , Germany
| | - Burkhard Hinz
- a Institute of Pharmacology and Toxicology , Rostock University Medical Center , Rostock , Germany
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Shu HF, Yu SX, Zhang CQ, Liu SY, Wu KF, Zang ZL, Yang H, Zhou SW, Yin Q. Expression of TRPV1 in cortical lesions from patients with tuberous sclerosis complex and focal cortical dysplasia type IIb. Brain Dev 2013; 35:252-60. [PMID: 22647236 DOI: 10.1016/j.braindev.2012.04.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 04/12/2012] [Accepted: 04/28/2012] [Indexed: 01/19/2023]
Abstract
Tuberous sclerosis complex (TSC) and focal cortical dysplasia type IIb (FCDIIb) are recognized as causes of intractable epilepsy. Transient receptor potential vanilloid receptor 1 (TRPV1), a member of the transient receptor potential family, is the capsaicin receptor and is known to be involved in peripheral nociception. Recent evidence suggested that TRPV1 may be a contributing factor in epileptogenicity. Here, we evaluated the expression of TRPV1 in the cortical lesions of TSC and FCDIIb relative to normal control cortex. TRPV1 was studied in epilepsy surgery cases with TSC (cortical tubers; n=12) and FCDIIb (n=12) using immunocytochemistry, confocal analysis, and Western blotting (WB). Immunohistochemical location of the TRPV1 was predominately detected in the abnormal cell types, such as dysmorphic neurons, balloon cells (BCs) and giant cells. Co-localization assays further revealed that cells expressing TRPV1 mainly had a neuronal lineage, apart from some BCs in FCDIIb, which obviously were of astrocytic lineage. The increased TRPV1 expression within the dysplastic cortex of TSC and FCDIIb was confirmed by WB. Interestingly, both immunohistochemical and WB data indicated that TRPV1 might have both cytoplasm and nuclear distribution, suggesting a potential nuclear role of TRPV1. The over-expression of TRPV1 in cortical lesions of TSC and FCDIIb suggested the possible involvement of TRPV1 in the intrinsic and increased epileptogenicity of malformations of cortical development associated epilepsy diseases and may represent a potential antiepileptogenic target. However, the current data are merely descriptive, and further electrophysiological investigation is needed in the future.
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Affiliation(s)
- Hai-Feng Shu
- Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, 183 Xinqiao Main Street, Shapingba District, Chongqing 400037, China
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Sun FJ, Guo W, Zheng DH, Zhang CQ, Li S, Liu SY, Yin Q, Yang H, Shu HF. Increased expression of TRPV1 in the cortex and hippocampus from patients with mesial temporal lobe epilepsy. J Mol Neurosci 2012; 49:182-93. [PMID: 22936245 DOI: 10.1007/s12031-012-9878-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Accepted: 08/14/2012] [Indexed: 12/30/2022]
Abstract
Transient receptor potential vanilloid type-1 (TRPV1) is a ligand-gated nonselective cation channel that has been well characterized in peripheral pain pathway. Recent evidence from animal models of temporal lobe epilepsy (TLE) has supported the important role of TRPV1 in epileptogenesis. In this study, we investigated the expression and cellular distribution of TRPV1 in the temporal cortex (CTX) and hippocampus (HPC) from 26 patients with mesial TLE (MTLE) compared with 12 histologically normal samples. Reverse transcription-PCR and Western blotting revealed up-regulated mRNA and protein levels of TRPV1 in the MTLE group versus the control group. Immunohistochemistry data demonstrated that TRPV1 was mainly distributed in the cell bodies and dendrites of neurons. Double-labeled immunofluorescence further revealed that TRPV1 was localized on NeuN-positive neurons and GFAP-positive astrocytes, but not on HLA-positive microglia. In addition, its co-localization with glutamate and gamma-aminobutyric acid (GABA) indicated that TRPV1 was distributed on both glutamatergic and GABAergic neurons. Moreover, nerve growth factor, a sensitizing factor for TRPV1, was showed a higher expression pattern in MTLE patients. Taken together, our findings suggest that the overexpression and distribution patterns of TRPV1 might be involved in the pathogenesis and epileptogenesis of human MTLE.
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Affiliation(s)
- Fei-Ji Sun
- Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, 2-V Xinqiao Street, Chongqing 400037, China
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Kovacs FE, Knop T, Urbanski MJ, Freiman I, Freiman TM, Feuerstein TJ, Zentner J, Szabo B. Exogenous and endogenous cannabinoids suppress inhibitory neurotransmission in the human neocortex. Neuropsychopharmacology 2012; 37:1104-14. [PMID: 22048459 PMCID: PMC3306870 DOI: 10.1038/npp.2011.262] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Activation of CB(1) receptors on axon terminals by exogenous cannabinoids (eg, Δ(9)-tetrahydrocannabinol) and by endogenous cannabinoids (endocannabinoids) released by postsynaptic neurons leads to presynaptic inhibition of neurotransmission. The aim of this study was to characterize the effect of cannabinoids on GABAergic synaptic transmission in the human neocortex. Brain slices were prepared from neocortical tissues surgically removed to eliminate epileptogenic foci. Spontaneous GABAergic inhibitory postsynaptic currents (sIPSCs) were recorded in putative pyramidal neurons using patch-clamp techniques. To enhance the activity of cannabinoid-sensitive presynaptic axons, muscarinic receptors were continuously stimulated by carbachol. The synthetic cannabinoid receptor agonist WIN55212-2 decreased the cumulative amplitude of sIPSCs. The CB(1) antagonist rimonabant prevented this effect, verifying the involvement of CB(1) receptors. WIN55212-2 decreased the frequency of miniature IPSCs (mIPSCs) recorded in the presence of tetrodotoxin, but did not change their amplitude, indicating that the neurotransmission was inhibited presynaptically. Depolarization of postsynaptic pyramidal neurons induced a suppression of sIPSCs. As rimonabant prevented this suppression, it is very likely that it was due to endocannabinods acting on CB(1) receptors. This is the first demonstration that an exogenous cannabinoid inhibits synaptic transmission in the human neocortex and that endocannabinoids released by postsynaptic neurons suppress synaptic transmission in the human brain. Interferences of cannabinoid agonists and antagonists with synaptic transmission in the cortex may explain the cognitive and memory deficits elicited by these drugs.
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Affiliation(s)
- Flora E Kovacs
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Tim Knop
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Michal J Urbanski
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Ilka Freiman
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Thomas M Freiman
- Neurochirurgische Klinik, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Thomas J Feuerstein
- Neurochirurgische Klinik, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Josef Zentner
- Neurochirurgische Klinik, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Bela Szabo
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Freiburg i. Br., Germany,Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 25, D-79104 Freiburg i. Br., Germany, Tel: +49 761 203 5312, Fax: +49 761 203 5318, E-mail:
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Hofmann ME, Frazier CJ. Marijuana, endocannabinoids, and epilepsy: potential and challenges for improved therapeutic intervention. Exp Neurol 2011; 244:43-50. [PMID: 22178327 DOI: 10.1016/j.expneurol.2011.11.047] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 11/25/2011] [Accepted: 11/29/2011] [Indexed: 10/14/2022]
Abstract
Phytocannabinoids isolated from the cannabis plant have broad potential in medicine that has been well recognized for many centuries. It is presumed that these lipid soluble signaling molecules exert their effects in both the central and peripheral nervous system in large part through direct interaction with metabotropic cannabinoid receptors. These same receptors are also targeted by a variety of endogenous cannabinoids including 2-arachidonoyl glycerol and anandamide. Significant effort over the last decade has produced an enormous advance in our understanding of both the cellular and the synaptic physiology of endogenous lipid signaling systems. This increase in knowledge has left us better prepared to carefully evaluate the potential for both natural and synthetic cannabinoids in the treatment of a variety of neurological disorders. In the case of epilepsy, long standing interest in therapeutic approaches that target endogenous cannabinoid signaling systems are, for the most part, not well justified by available clinical data from human epileptics. Nevertheless, basic science experiments have clearly indicated a key role for endogenous cannabinoid signaling systems in moment to moment regulation of neuronal excitability. Further it has become clear that these systems can both alter and be altered by epileptiform activity in a wide range of in vitro and in vivo models of epilepsy. Collectively these observations suggest clear potential for effective therapeutic modulation of endogenous cannabinoid signaling systems in the treatment of human epilepsy, and in fact, further highlight key obstacles that would need to be addressed to reach that goal.
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Affiliation(s)
- Mackenzie E Hofmann
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, USA
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Kiss LE, Ferreira HS, Beliaev A, Torrão L, Bonifácio MJ, Learmonth DA. Design, synthesis, and structure–activity relationships of 1,3,4-oxadiazol-2(3H)-ones as novel FAAH inhibitors. MEDCHEMCOMM 2011. [DOI: 10.1039/c1md00136a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Nithipatikom K, Isbell MA, Endsley MP, Woodliff JE, Campbell WB. Anti-proliferative effect of a putative endocannabinoid, 2-arachidonylglyceryl ether in prostate carcinoma cells. Prostaglandins Other Lipid Mediat 2010; 94:34-43. [PMID: 21167293 DOI: 10.1016/j.prostaglandins.2010.12.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 11/16/2010] [Accepted: 12/08/2010] [Indexed: 12/31/2022]
Abstract
Endocannabinoids (ECs), anandamide (AEA) and 2-arachidonoylglycerol (2-AG), inhibit proliferation of carcinoma cells. Several enzymes hydrolyze ECs to reduce endogenous EC concentrations and produce eicosanoids that promote cell growth. In this study, we determined the effects of EC hydrolysis inhibitors and a putative EC, 2-arachidonylglyceryl ether (noladin ether, NE) on proliferation of prostate carcinoma (PC-3, DU-145, and LNCaP) cells. PC-3 cells had the least specific hydrolysis activity for AEA and administration of AEA effectively inhibited cell proliferation. The proliferation inhibition was blocked by SR141716A (a selective CB1R antagonist) but not SR144528 (a selective CB2R antagonist), suggesting a CB1R-mediated inhibition mechanism. On the other hand, specific hydrolysis activity for 2-AG was high and 2-AG inhibited proliferation only in the presence of EC hydrolysis inhibitors. NE inhibited proliferation in a concentration-dependent manner; however, SR141716A, SR144528 and pertussis toxin did not block the NE-inhibited proliferation, suggesting a CBR-independent mechanism of NE. A peroxisome proliferator-activated receptor gamma (PPARγ) antagonist GW9662 did not block the NE-inhibited proliferation, suggesting that PPARγ was not involved. NE also induced cell cycle arrest in G(0)/G(1) phase in PC-3 cells. NE inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB p65) and down-regulated the expression of cyclin D1 and cyclin E in PC-3 cells, suggesting the NF-κB/cyclin D and cyclin E pathways are involved in the arrest of G1 cell cycle and inhibition of cell growth. These results indicate therapeutic potentials of EC hydrolysis inhibitors and the enzymatically stable NE in prostate cancer.
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Affiliation(s)
- Kasem Nithipatikom
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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Hill AJ, Weston SE, Jones NA, Smith I, Bevan SA, Williamson EM, Stephens GJ, Williams CM, Whalley BJ. Δ⁹-Tetrahydrocannabivarin suppresses in vitro epileptiform and in vivo seizure activity in adult rats. Epilepsia 2010; 51:1522-32. [PMID: 20196794 DOI: 10.1111/j.1528-1167.2010.02523.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE We assessed the anticonvulsant potential of the phytocannabinoid Δ⁹-tetrahydrocannabivarin (Δ⁹-THCV) by investigating its effects in an in vitro piriform cortex (PC) brain slice model of epileptiform activity, on cannabinoid CB1 receptor radioligand-binding assays and in a generalized seizure model in rats. METHODS Δ⁹-THCV was applied before (10 μm Δ⁹-THCV) or during (10-50 μm Δ⁹-THCV) epileptiform activity induced by Mg²(+) -free extracellular media in adult rat PC slices and measured using multielectrode array (MEA) extracellular electrophysiologic techniques. The actions of Δ⁹-THCV on CB1 receptors were examined using [³H]SR141716A competition binding and [³⁵S]GTPγS assays in rat cortical membranes. Effects of Δ⁹-HCV (0.025-2.5 mg/kg) on pentylenetetrazole (PTZ)-induced seizures in adult rats were also assessed. RESULTS After induction of stable spontaneous epileptiform activity, acute Δ⁹ -THCV application (≥ 20 μm) significantly reduced burst complex incidence and the amplitude and frequency of paroxysmal depolarizing shifts (PDSs). Furthermore, slices pretreated with 10 μm Δ⁹-THCV prior to induction of epileptiform activity exhibited significantly reduced burst complex incidence and PDS peak amplitude. In radioligand-binding experiments, Δ⁹-THCV acted as a CB1 receptor ligand, displacing 0.5 nm [³H]SR141716A with a Ki∼290 nm, but exerted no agonist stimulation of [³⁵S]GTPγS binding. In PTZ-induced seizures in vivo, 0.25 mg/kg Δ⁹-THCV significantly reduced seizure incidence. DISCUSSION These data demonstrate that Δ⁹-THCV exerts antiepileptiform and anticonvulsant properties, actions that are consistent with a CB1 receptor-mediated mechanism and suggest possible therapeutic application in the treatment of pathophysiologic hyperexcitability states.
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Affiliation(s)
- Andrew J Hill
- School of Pharmacy, University of Reading, Whiteknights, Reading, Berkshire, UK
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Fu M, Xie Z, Zuo H. TRPV1: a potential target for antiepileptogenesis. Med Hypotheses 2009; 73:100-2. [PMID: 19328632 DOI: 10.1016/j.mehy.2009.01.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2008] [Revised: 11/23/2008] [Accepted: 01/06/2009] [Indexed: 10/21/2022]
Abstract
Epilepsy is one of the most common diseases in neurology department. It is caused by many different kinds of perturbances of normal balance of excitation and inhibition within the central nervous system. Current clinical antiepileptic drugs (AEDs) targets include ion channels, neurotransmitter transporters and neurotransmitter metabolic enzymes. They could control about 70-80% of the patients' symptoms; 20-30% patients develop to be intractable epilepsy sufferers. Moreover, antiepileptic drugs could not prevent formation of foci and disease process, but only alleviate symptoms of seizures at risk of different adverse effects as the consequences of large doses. Recently, impressive data on the actions of transient receptor potential vanilloid receptor 1 (TRPV1) prove it to be an inspiring antiepileptogenic target. TRPV1 activation modulates activity-dependent synaptic efficacy: (i) facilitating long-term potentiation (LTP) and suppressing long-term depression (LTD) of hippocampal neurons (ii) selectively inhibiting excitatory synapses onto hippocampal interneurons, which is expected to increase the excitability of innervated pyramidal cells. Nerve growth factor (NGF) can acutely and chronically upregulates TRPV1 expression, suggesting that TRPV1 channels would play an important role in the course of NGF regulated epileptogenesis. Endocannabinoid anandamide (AEA) is one of the TRPV1 endogenous agonists. It has been proved that, in the course of epilepsy, AEA levels increases due to enhanced formation and both exogenously administered and endogenously produced AEA display proconvulsant activity. Moreover, TRPV1 activation triggers apoptotic neuronal death of rat cortical cultures, which may be responsible, at least in part, for the volume loss of neocortex in chronic epilepsy. Our hypothesis may broaden the drug screening and designing for clinical strategies for epilepsy treatment.
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Affiliation(s)
- Min Fu
- Medical College, Tsinghua University, Beijing 100084, China
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Kozłowska H, Baranowska M, Schlicker E, Kozłowski M, Laudañski J, Malinowska B. Virodhamine relaxes the human pulmonary artery through the endothelial cannabinoid receptor and indirectly through a COX product. Br J Pharmacol 2008; 155:1034-42. [PMID: 18806815 DOI: 10.1038/bjp.2008.371] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE The endocannabinoid virodhamine is a partial agonist at the cannabinoid CB(1) receptor and a full agonist at the CB(2) receptor, and relaxes rat mesenteric arteries through endothelial cannabinoid receptors. Its concentration in the periphery exceeds that of the endocannabinoid anandamide. Here, we examined the influence of virodhamine on the human pulmonary artery. EXPERIMENTAL APPROACH Isolated human pulmonary arteries were obtained during resections for lung carcinoma. Vasorelaxant effects of virodhamine were examined on endothelium-intact vessels precontracted with 5-HT or KCl. KEY RESULTS Virodhamine, unlike WIN 55,212-2, relaxed 5-HT-precontracted vessels concentration dependently. The effect of virodhamine was reduced by endothelium denudation, two antagonists of the endothelial cannabinoid receptor, cannabidiol and O-1918, and a high concentration of the CB(1) receptor antagonist rimonabant (5 muM), but only slightly attenuated by the NOS inhibitor L-NAME and not affected by a lower concentration of rimonabant (100 nM) or by the CB(2) and vanilloid receptor antagonists SR 144528 and capsazepine, respectively. The COX inhibitor indomethacin and the fatty acid amide hydrolase inhibitor URB597 and combined administration of selective blockers of small (apamin) and intermediate and large (charybdotoxin) conductance Ca(2+)-activated K(+) channels attenuated virodhamine-induced relaxation. The vasorelaxant potency of virodhamine was lower in KCl- than in 5-HT-precontracted preparations. CONCLUSIONS AND IMPLICATIONS Virodhamine relaxes the human pulmonary artery through the putative endothelial cannabinoid receptor and indirectly through a COX-derived vasorelaxant prostanoid formed from the virodhamine metabolite, arachidonic acid. One or both of these mechanisms may stimulate vasorelaxant Ca(2+)-activated K(+) channels.
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Affiliation(s)
- H Kozłowska
- Department of Experimental Physiology, Medical University of Białystok, Białystok, Poland.
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15
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Snider NT, Sikora MJ, Sridar C, Feuerstein TJ, Rae JM, Hollenberg PF. The endocannabinoid anandamide is a substrate for the human polymorphic cytochrome P450 2D6. J Pharmacol Exp Ther 2008; 327:538-45. [PMID: 18698000 DOI: 10.1124/jpet.108.141796] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Members of the cytochrome P450 (P450) family of drug-metabolizing enzymes are present in the human brain, and they may have important roles in the oxidation of endogenous substrates. The polymorphic CYP2D6 is one of the major brain P450 isoforms and has been implicated in neurodegeneration, psychosis, schizophrenia, and personality traits. The objective of this study was to determine whether the endocannabinoid arachidonoylethanolamide (anandamide) is a substrate for CYP2D6. Anandamide is the endogenous ligand to the cannabinoid receptor CB1, which is also activated by the main psychoactive component in marijuana. Signaling via the CB1 receptor alters sensory and motor function, cognition, and emotion. Recombinant CYP2D6 converted anandamide to 20-hydroxyeicosatetraenoic acid ethanolamide and 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acid ethanolamides (EET-EAs) with low micromolar K(m) values. CYP2D6 further metabolized the epoxides of anandamide to form novel dioxygenated derivatives. Human brain microsomal and mitochondrial preparations metabolized anandamide to form hydroxylated and epoxygenated products, respectively. An inhibitory antibody against CYP2D6 significantly decreased the mitochondrial formation of the EET-EAs. To our knowledge, anandamide and its epoxides are the first eicosanoid-like molecules to be identified as CYP2D6 substrates. Our study suggests that anandamide may be a physiological substrate for brain mitochondrial CYP2D6, implicating this polymorphic enzyme as a potential component of the endocannabinoid system in the brain. This study also offers support to the hypothesis that neuropsychiatric phenotype differences among individuals with genetic variations in CYP2D6 could be ascribable to interactions of this enzyme with endogenous substrates.
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Affiliation(s)
- Natasha T Snider
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109-5632, USA
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16
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Muccioli GG, Stella N. An optimized GC-MS method detects nanomolar amounts of anandamide in mouse brain. Anal Biochem 2007; 373:220-8. [PMID: 17981259 DOI: 10.1016/j.ab.2007.09.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Accepted: 09/25/2007] [Indexed: 10/22/2022]
Abstract
The endocannabinoids anandamide and 2-arachidonoylglycerol, as well as several anandamide-related N-acylethanolamines, belong to a family of lipid transmitter that regulate fundamental physiological processes, including neurotransmission and neuroinflammation. Their precise quantification in biological matrices can be achieved by gas chromatography-mass spectrometry (GC-MS), but this method typically requires multiple time-consuming purification steps such as solid-phase extraction followed by HPLC. Here we report a novel solid-phase extraction procedure allowing for single-step, and thus higher throughput, purification of endocannabinoids and N-acylethanolamines before GC-MS quantification. We determined the minimal amount of mouse brain tissue required to reliably detect endocannabinoids and N-acylethanolamines when using this approach and provide direct evidence for quantification accuracy by using radioactive and deuterated standards spiked into mouse brain samples. Using this method, we found that mouse brain contains much higher levels of anandamide (>1 nmol/g tissue) than previously reported, whereas levels of 2-arachidonoylglycerol and other N-acylethanolamines are well within the range of previous reports. In addition, we show that mouse brain amounts of endocannabinoids and N-acylethanolamines differ depending on animal gender as well as on whether the tissue was fixed or not. Our study shows that endocannabinoid and N-acylethanolamine levels quantified in mouse brain by GC-MS depend closely on tissue amount and preparation as well as on animal gender and that, depending on such parameters, anandamide levels could be underestimated.
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Affiliation(s)
- Giulio G Muccioli
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
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17
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Vandevoorde S, Lambert DM. The Multiple Pathways of Endocannabinoid Metabolism: A Zoom Out. Chem Biodivers 2007; 4:1858-81. [PMID: 17712823 DOI: 10.1002/cbdv.200790156] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Séverine Vandevoorde
- Unité de chimie pharmaceutique et radiopharmacie, UCL/CMFA 7340, Avenue E. Mounier, B-1200 Brussels.
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18
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