Cannabinoid contents in cannabis products seized in Sao Paulo, Brazil, 2006-2007

A rapid and simple method was optimized for determination of Delta(9)-tetrahydrocannabinol (Delta(9)-THC), cannabidiol (CBD), and cannabinol (CBN) contents in cannabis products by gas chromatography with flame-ionization detection (GC-FID), using diazepam as internal standard. All parameters of validation of the method such as linearity, intraassay precision, and limits of detection and quantification of the analytes were satisfactory. Using the described method, cannabinoid contents of 55 cannabis product samples seized in Sao Paulo City, Brazil, in 2006 and 2007 were measured. Delta(9)-THC content in marijuana and hashish samples varied between 0.08% and 5.5%, with an average of 2.5%. The phenotypic ratio showed that the products were able to be designated as ""drug type.""

Modulation of Mediotemporal and Ventrostriatal Function in Humans by Delta 9-Tetrahydrocannabinol A Neural Basis for the Effects of Cannabis sativa on Learning and Psychosis

Context: Cannabis sativa use can impair verbal learning, provoke acute psychosis, and increase the risk of schizophrenia. It is unclear where C sativa acts in the human brain to modulate verbal learning and to induce psychotic symptoms. Objectives: To investigate the effects of 2 main psychoactive constituents of C sativa, Delta 9-tetrahydrocannabinol (Delta 9-THC) and cannabidiol, on regional brain function during verbal paired associate learning. Design: Subjects were studied on 3 separate occasions using a block design functional magnetic resonance imaging paradigm while performing a verbal paired associate learning task. Each imaging session was preceded by the ingestion of Delta 9-THC (10 mg), cannabidiol (600 mg), or placebo in a double-blind, randomized, placebo-controlled, repeated-measures, within-subject design. Setting: University research center. Participants: Fifteen healthy, native English-speaking, right-handed men of white race/ethnicity who had used C sativa 15 times or less and had minimal exposure to other illicit drugs in their lifetime. Main Outcome Measures: Regional brain activation ( blood oxygen level-dependent response), performance in a verbal learning task, and objective and subjective ratings of psychotic symptoms, anxiety, intoxication, and sedation. Results: Delta 9-Tetrahydrocannabinol increased psychotic symptoms and levels of anxiety, intoxication, and sedation, whereas no significant effect was noted on these parameters following administration of cannabidiol. Performance in the verbal learning task was not significantly modulated by either drug. Administration of Delta 9-THC augmented activation in the parahippocampal gyrus during blocks 2 and 3 such that the normal linear decrement in activation across repeated encoding blocks was no longer evident. Delta 9-Tetrahydrocannabinol also attenuated the normal time-dependent change in ventrostriatal activation during retrieval of word pairs, which was directly correlated with concurrently induced psychotic symptoms. In contrast, administration of cannabidiol had no such effect. Conclusion: The modulation of mediotemporal and ventrostriatal function by Delta 9-THC may underlie the effects of C sativa on verbal learning and psychotic symptoms, respectively.

Endocannabinoid system and psychiatry: in search of a neurobiological basis for detrimental and potential therapeutic effects.

Public concern on mental health has noticeably increased given the high prevalence of neuropsychiatric disorders. Cognition and emotionality are the most affected functions in neuropsychiatric disorders, i.e., anxiety disorders, depression, and schizophrenia. In this review, most relevant literature on the role of the endocannabinoid (eCB) system in neuropsychiatric disorders will be presented. Evidence from clinical and animal studies is provided for the participation of CB1 and CB2 receptors (CB1R and CB2R) in the above mentioned neuropsychiatric disorders. CBRs are crucial in some of the emotional and cognitive impairments reported, although more research is required to understand the specific role of the eCB system in neuropsychiatric disorders. Cannabidiol (CBD), the main non-psychotropic component of the Cannabis sativa plant, has shown therapeutic potential in several neuropsychiatric disorders. Although further studies are needed, recent studies indicate that CBD therapeutic effects may partially depend on facilitation of eCB-mediated neurotransmission. Last but not least, this review includes recent findings on the role of the eCB system in eating disorders. A deregulation of the eCB system has been proposed to be in the bases of several neuropsychiatric disorders, including eating disorders. Cannabis consumption has been related to the appearance of psychotic symptoms and schizophrenia. In contrast, the pharmacological manipulation of this eCB system has been proposed as a potential strategy for the treatment of anxiety disorders, depression, and anorexia nervosa. In conclusion, the eCB system plays a critical role in psychiatry; however, detrimental consequences of manipulating this endogenous system cannot be underestimated over the potential and promising perspectives of its therapeutic manipulation.

Distribution of free and conjugated cannabinoids in human bile samples.

The metabolism of Δ(9)-tetrahydrocannabinol (THC) is relatively complex, and over 80 metabolites have been identified. However, much less is known about the formation and fate of cannabinoid conjugates. Bile excretion is known to be an important route for the elimination of phase II metabolites. A liquid chromatography-tandem mass spectrometry LC-MS/MS procedure for measuring cannabinoids in oral fluid was adapted, validated and applied to 10 bile samples. THC, 11-hydroxy-Δ(9)-tetrahydrocannabinol (11-OH-THC), 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THCCOOH), cannabinol (CBN), cannabidiol (CBD), Δ(9)-tetrahydrocannabinolic acid A (THC-A), 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol glucuronide (THCCOOH-gluc) and Δ(9)-tetrahydrocannabinol glucuronide (THC-gluc) were determined following solid-phase extraction and LC-MS/MS. High concentrations of THCCOOH-gluc were found in bile samples (range: 139-21,275 ng/mL). Relatively high levels of THCCOOH (7.7-1548 ng/mL) and THC-gluc (38-1366 ng/mL) were also measured. THC-A, the plant precursor of THC, was the only cannabinoid that was not detected. These results show that biliary excretion is an important route of elimination for cannabinoids conjugates and that their enterohepatic recirculation is a significant factor to consider when analyzing blood elimination profiles of cannabinoids. Furthermore, we suggest that the bile is the matrix of choice for the screening of phase II cannabinoid metabolites.

Consommation de cannabis : quels sont les risques ?

Abstract - Cannabis: what are the risks ? Cannabinoids from cannabis have a dual use and display often opposite pharmacological properties depending on the circumstances of use and the administered dose. Cannabinoids constitute mainly a recreative or addictive substance, but also a therapeutic drug. They can be either neurotoxic or neuroprotector, carcinogenic or an anti-cancer drug, hyperemetic or antiemetic, pro-inflammatory or anti-inflammatory... Improvement in in-door cultivation techniques and selection of high yield strains have resulted in a steadily increase of THC content. Cannabis is the most frequently prohibited drug used in Switzerland and Western countries. About half of teenagers have already experimented cannabis consumption. About 10% of cannabis users smoke it daily and can be considered as cannabis-dependant. About one third of these cannabis smokers are chronically intoxicated. THC, the main psychoactive drug interacts with the endocannnabinoid system which is made of cellular receptors, endogenous ligands and a complex intra-cellular biosynthetic, degradation and intra-cellular messengers machinery. The endocannabinoid system plays a major role in the fine tuning of the nervous system. It is thought to be important in memory, motor learning, and synaptic plasticity. At psychoactive dose, THC impairs psychomotor and neurocognitive performances. Learning and memory abilities are diminished. The risk to be responsible of a traffic car accident is slightly increased after administration of cannabis alone and strongly increased after combined use of alcohol and cannabis. With the exception of young children, cannabis intake does not lead to potentially fatal intoxication. However, cannabis exposure can act as trigger for cardiovascular accidents in rare vulnerable people. Young or vulnerable people are more at risk to develop a psychosis at adulthood and/or to become cannabis-dependant. Epidemiological studies have shown that the risk to develop a schizophrenia at adulthood is increased for cannabis smokers, especially for those who are early consumers. Likewise for the risk of depression and suicide attempt. Respiratory disease can be worsen after cannabis smoking. Pregnant and breast-feeding mothers should not take cannabis because THC gets into placenta and concentrates in breast milk. The most sensitive time-period to adverse side-effects of cannabis starts from foetus and extends to adolescence. The reason could be that the endocannabinoid system, the main target of THC, plays a major role in the setup of neuronal networks in the immature brain. The concomitant use of other psychoactive drugs such as alcohol, benzodiazepines or cocaine should be avoided because of possible mutual interactions. Furthermore, it has been demonstrated that a cross-sensitisation exists between most addictive drugs at the level of the brain reward system. Chronic use of cannabis leads to tolerance and withdrawals symptoms in case of cannabis intake interruption. Apart from the aforementioned unwanted side effects, cannabis displays useful and original medicinal properties which are currently under scientific evaluation. At the moment the benefit/risk ratio is not yet well assessed. Several minor phytocannabinoids or synthetic cannabinoids devoid of psychoactive properties could find their way in the modern pharmacopoeia (e.g. ajulemic acid). For therapeutic purposes, special cannabis varieties with unique cannabinoids composition (e.g. a high cannabidiol content) are preferred over those which are currently used for recreative smoking. The administration mode also differs in such a way that inhalation of carcinogenic pyrolytic compounds resulting from cannabis smoking is avoided. This can be achieved by inhaling cannabis vapors at low temperature with a vaporizer device. Résumé Les cannabinoïdes contenus dans la plante de cannabis ont un double usage et possèdent des propriétés opposées suivant les circonstances et les doses employées. Les cannabinoïdes, essentiellement drogue récréative ou d'abus pourraient, pour certains d'entre eux, devenir des médicaments. Selon les conditions d'utilisation, ils peuvent être neurotoxiques ou neuroprotecteurs, carcinogènes ou anticancéreux, hyper-émétiques ou antiémétiques, pro-inflammatoires ou anti-inflammatoires... Les techniques de culture sous serre indoor ainsi que la sélection de variétés de cannabis à fort potentiel de production ont conduit à un accroissement notable des taux de THC. Le cannabis est la drogue illégale la plus fréquemment consommée en Suisse et ailleurs dans le monde occidental. Environ la moitié des jeunes ont déjà expérimenté le cannabis. Environ 10 % des consommateurs le fument quotidiennement et en sont devenus dépendants. Un tiers de ces usagers peut être considéré comme chroniquement intoxiqué. Le THC, la principale substance psychoactive du cannabis, interagit avec le "système endocannabinoïde". Ce système est composé de récepteurs cellulaires, de ligands endogènes et d'un dispositif complexe de synthèse, de dégradation, de régulation et de messagers intra-cellulaires. Le système endocannabinoïde joue un rôle clé dans le réglage fin du système nerveux. Les endocannabinoïdes régulent la mémorisation, l'apprentissage moteur et la plasticité des liaisons nerveuses. À dose psychoactive, le THC réduit les performances psychomotrices et neurocognitives. Les facultés d'apprentissage et de mémorisation sont diminuées. Le risque d'être responsable d'un accident de circulation est augmenté après prise de cannabis, et ceci d'autant plus que de l'alcool aura été consommé parallèlement. À l'exception des jeunes enfants, la consommation de cannabis n'entraîne pas de risque potentiel d'intoxication mortelle. Toutefois, le cannabis pourrait agir comme facteur déclenchant d'accident cardiovasculaire chez de rares individus prédisposés. Les individus jeunes, et/ou vulnérables ont un risque significativement plus élevé de développer une psychose à l'âge adulte ou de devenir dépendant au cannabis. Des études épidémiologiques ont montré que le risque de développer une schizophrénie à l'âge adulte était augmenté pour les consommateurs de cannabis et ceci d'autant plus que l'âge de début de consommation était précoce. Il en va de même pour le risque de dépression. Les troubles respiratoires pourraient être exacerbés par la prise de cannabis. Les femmes enceintes et celles qui allaitent ne devraient pas consommer de cannabis car le THC traverse la barrière hémato-placentaire, en outre, il se concentre dans le lait maternel. La période de la vie la plus sensible aux effets néfastes du cannabis correspond à celle allant du foetus à l'adolescent. Le système endocannabinoïde sur lequel agit le THC serait en effet un acteur majeur orchestrant le développement des réseaux neuronaux dans le cerveau immature. La prise concomitante d'autres psychotropes comme l'alcool, les benzodiazépines ou la cocaïne conduit à des renforcements mutuels de leurs effets délétères. De plus, il a été montré l'existence d'une sensibilité croisée pour la majorité des psychotropes qui agissent sur le système de la récompense, le cannabis y compris, ce qui augmente ainsi le risque de pharmacodépendance. La prise régulière de doses élevées de cannabis entraîne l'apparition d'une tolérance et de symptômes de sevrage discrets à l'arrêt de la consommation. À part les effets négatifs mentionnés auparavant, le cannabis possède des propriétés médicales originales qui sont l'objet d'études attentives. Plusieurs cannabinoïdes mineurs naturels ou synthétiques, comme l'acide ajulémique, pourraient trouver un jour une place dans la pharmacopée. En usage thérapeutique, des variétés particulières de cannabis sont préférées, par exemple celles riches en cannabidiol non psychoactif. Le mode d'administration diffère de celui utilisé en mode récréatif. Par exemple, la vaporisation des cannabinoïdes à basse température est préférée à l'inhalation du "joint".

Consommation de cannabis : quels sont les risques?

Résumé - Les cannabinoïdes contenus dans la plante de cannabis ont un double usage et possèdent des propriétés opposées suivant les circonstances et les doses employées. Les cannabinoïdes, essentiellement drogue récréative ou d'abus pourraient, pour certains d'entre eux, devenir des médicaments. Selon les conditions d'utilisation, ils peuvent être neurotoxiques ou neuroprotecteurs, carcinogènes ou anticancéreux, hyper-émétiques ou antiémétiques, pro-inflammatoires ou anti-inflammatoires. . . Les techniques de culture sous serre indoor ainsi que la sélection de variétés de cannabis à fort potentiel de production ont conduit à un accroissement notable des taux de THC. Le cannabis est la drogue illégale la plus fréquemment consommée en Suisse et ailleurs dans le monde occidental. Environ la moitié des jeunes ont déjà expérimenté le cannabis. Environ 10 % des consommateurs le fument quotidiennement et en sont devenus dépendants. Un tiers de ces usagers peut être considéré comme chroniquement intoxiqué. Le THC, la principale substance psychoactive du cannabis, interagit avec le « système endocannabinoïde ». Ce système est composé de récepteurs cellulaires, de ligands endogènes et d'un dispositif complexe de synthèse, de dégradation, de régulation et de messagers intra-cellulaires. Le système endocannabinoïde joue un rôle clé dans le réglage fin du système nerveux. Les endocannabinoïdes régulent la mémorisation, l'apprentissage moteur et la plasticité des liaisons nerveuses. À dose psychoactive, le THC réduit les performances psychomotrices et neurocognitives. Les facultés d'apprentissage et de mémorisation sont diminuées. Le risque d'être responsable d'un accident de circulation est augmenté après prise de cannabis, et ceci d'autant plus que de l'alcool aura été consommé parallèlement. À l'exception des jeunes enfants, la consommation de cannabis n'entraîne pas de risque potentiel d'intoxication mortelle. Toutefois, le cannabis pourrait agir comme facteur déclenchant d'accident cardiovasculaire chez de rares individus prédisposés. Les individus jeunes, et/ou vulnérables ont un risque significativement plus élevé de développer une psychose à l'âge adulte ou de devenir dépendant au cannabis. Des études épidémiologiques ont montré que le risque de développer une schizophrénie à l'âge adulte était augmenté pour les consommateurs de cannabis et ceci d'autant plus que l'âge de début de consommation était précoce. Il en va de même pour le risque de dépression. Les troubles respiratoires pourraient être exacerbés par la prise de cannabis. Les femmes enceintes et celles qui allaitent ne devraient pas consommer de cannabis car le THC traverse la barrière hémato-placentaire, en outre, il se concentre dans le lait maternel. La période de la vie la plus sensible aux effets néfastes du cannabis correspond à celle allant du foetus à l'adolescent. Le système endocannabinoïde sur lequel agit le THC serait en effet un acteur majeur orchestrant le développement des réseaux neuronaux dans le cerveau immature. La prise concomitante d'autres psychotropes comme l'alcool, les benzodiazépines ou la cocaïne conduit à des renforcements mutuels de leurs effets délétères. De plus, il a été montré l'existence d'une sensibilité croisée pour la majorité des psychotropes qui agissent sur le système de la récompense, le cannabis y compris, ce qui augmente ainsi le risque de pharmacodépendance. La prise régulière de doses élevées de cannabis entraîne l'apparition d'une tolérance et de symptômes de sevrage discrets à l'arrêt de la consommation. À part les effets négatifs mentionnés auparavant, le cannabis possède des propriétés médicales originales qui sont l'objet d'études attentives. Plusieurs cannabinoïdes mineurs naturels ou synthétiques, comme l'acide ajulémique, pourraient trouver un jour une place dans la pharmacopée. En usage thérapeutique, des variétés particulières de cannabis sont préférées, par exemple celles riches en cannabidiol non psychoactif. Le mode d'administration diffère de celui utilisé en mode récréatif. Par exemple, la vaporisation des cannabinoïdes à basse température est préférée à l'inhalation du « joint »

Analysis of cannabinoids in oral fluid by liquid chromatography-tandem mass spectrometry

A sensitive method was developed for quantifying a wide range of cannabinoids in oral fluid (OF) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These cannabinoids include a dagger(9)-tetrahydrocannabinol (THC), 11-hydroxy-a dagger(9)-tetrahydrocannabinol (11-OH-THC), 11-nor-9-carboxy-a dagger(9)-tetrahydrocannabinol (THCCOOH), cannabinol (CBN), cannabidiol (CBD), a dagger(9)-tetrahydrocannabinolic acid A (THC-A), 11-nor-9-carboxy-a dagger(9)-tetrahydrocannabinol glucuronide (THCCOOH-gluc), and a dagger(9)-tetrahydrocannabinol glucuronide (THC-gluc). Samples were collected using a Quantisal (TM) device. The advantages of performing a liquid-liquid extraction (LLE) of KCl-saturated OF using heptane/ethyl acetate versus a solid-phase extraction (SPE) using HLB copolymer columns were determined. Chromatographic separation was achieved in 11.5 min on a Kinetex (TM) column packed with 2.6-mu m core-shell particles. Both positive (THC, 11-OH-THC, CBN, and CBD) and negative (THCCOOH, THC-gluc, THCCOOH-gluc, and THC-A) electrospray ionization modes were employed with multiple reaction monitoring using a high-end AB Sciex API 5000 (TM) triple quadrupole LC-MS/MS system. Unlike SPE, LLE failed to extract THC-gluc and THCCOOH-gluc. However, the LLE method was more sensitive for the detection of THCCOOH than the SPE method, wherein the limit of detection (LOD) and limit of quantification (LOQ) decreased from 100 to 50 pg/ml and from 500 to 80 pg/ml, respectively. The two extraction methods were successfully applied to OF samples collected from volunteers before and after they smoked a homemade cannabis joint. High levels of THC were measured soon after smoking, in addition to significant amounts of THC-A. Other cannabinoids were found in low concentrations. Glucuronide conjugate levels were lower than the method's LOD for most samples. Incubation studies suggest that glucuronides could be enzymatically degraded by glucuronidase prior to OF collection

Hemispheric language asymmetry in first episode psychosis and schizotypy : the role of cannabis consumption and cognitive disorganization

Cannabis use has been related to an elevated psychosis risk and attenuated cognitive functioning. Cannabis-related cognitive impairments are also observed in populations along the psychosis dimension. We here investigated whether a potential behavioural marker of the psychosis dimension (attenuated functional hemispheric asymmetry) is even further attenuated in individuals using cannabis (CU) versus those not using cannabis (nCU). We tested 29 patients with first episode psychosis (FEP; 11 CU) and 90 healthy controls (38 CU) on lateralized lexical decisions assessing left hemisphere language dominance. In patients, psychotic symptoms were assessed (PANSS). In controls, self-reported schizotypy was assessed (O-LIFE questionnaire). Results indicated that nCU FEP patients had a relative reduced hemispheric asymmetry, as did controls with increasing cognitive disorganisation scores, in particular when belonging to the group of nCU controls. Positive, disorganised and negative PANSS scores in patients and negative and positive schizotypy in controls were unrelated to hemispheric asymmetry. These findings suggest that cannabis use balances rather than exacerbates uncommon hemispheric laterality patterns. Moreover, in healthy populations, the potential stabilisation of typical hemispheric asymmetry in CU might be most relevant to individuals with elevated cognitive disorganisation. We discuss the potential beneficial and harmful effects of cannabis use along the psychosis dimension together with propositions for future studies that should account for the mediating role of additional substances (e.g. nicotine), cannabis composition (e.g. cannabidiol content), and individual differences (e.g. physical health, or absence of significant polysubstance use).

E-Cigarettes: A Review of New Trends in Cannabis Use.

The emergence of electronic cigarettes (e-cigs) has given cannabis smokers a new method of inhaling cannabinoids. E-cigs differ from traditional marijuana cigarettes in several respects. First, it is assumed that vaporizing cannabinoids at lower temperatures is safer because it produces smaller amounts of toxic substances than the hot combustion of a marijuana cigarette. Recreational cannabis users can discretely "vape" deodorized cannabis extracts with minimal annoyance to the people around them and less chance of detection. There are nevertheless several drawbacks worth mentioning: although manufacturing commercial (or homemade) cannabinoid-enriched electronic liquids (e-liquids) requires lengthy, complex processing, some are readily on the Internet despite their lack of quality control, expiry date, and conditions of preservation and, above all, any toxicological and clinical assessment. Besides these safety problems, the regulatory situation surrounding e-liquids is often unclear. More simply ground cannabis flowering heads or concentrated, oily THC extracts (such as butane honey oil or BHO) can be vaped in specially designed, pen-sized marijuana vaporizers. Analysis of a commercial e-liquid rich in cannabidiol showed that it contained a smaller dose of active ingredient than advertised; testing our laboratory-made, purified BHO, however, confirmed that it could be vaped in an e-cig to deliver a psychoactive dose of THC. The health consequences specific to vaping these cannabis preparations remain largely unknown and speculative due to the absence of comprehensive, robust scientific studies. The most significant health concerns involve the vaping of cannabinoids by children and teenagers. E-cigs could provide an alternative gateway to cannabis use for young people. Furthermore, vaping cannabinoids could lead to environmental and passive contamination.

Medicinal cannabis: is delta9-tetrahydrocannabinol necessary for all its effects?

Cannabis is under clinical investigation to assess its potential for medicinal use, but the question arises as to whether there is any advantage in using cannabis extracts compared with isolated Delta9-trans-tetrahydrocannabinol (Delta9THC), the major psychoactive component. We have compared the effect of a standardized cannabis extract (SCE) with pure Delta9THC, at matched concentrations of Delta9THC, and also with a Delta9THC-free extract (Delta9THC-free SCE), using two cannabinoid-sensitive models, a mouse model of multiple sclerosis (MS), and an in-vitro rat brain slice model of epilepsy. Whilst SCE inhibited spasticity in the mouse model of MS to a comparable level, it caused a more rapid onset of muscle relaxation, and a reduction in the time to maximum effect compared with Delta9THC alone. The Delta9THC-free extract or cannabidiol (CBD) caused no inhibition of spasticity. However, in the in-vitro epilepsy model, in which sustained epileptiform seizures were induced by the muscarinic receptor agonist oxotremorine-M in immature rat piriform cortical brain slices, SCE was a more potent and again more rapidly-acting anticonvulsant than isolated Delta9THC, but in this model, the Delta9THC-free extract also exhibited anticonvulsant activity. Cannabidiol did not inhibit seizures, nor did it modulate the activity of Delta9THC in this model. Therefore, as far as some actions of cannabis were concerned (e.g. antispasticity), Delta9THC was the active constituent, which might be modified by the presence of other components. However, for other effects (e.g. anticonvulsant properties) Delta9THC, although active, might not be necessary for the observed effect. Above all, these results demonstrated that not all of the therapeutic actions of cannabis herb might be due to the Delta9THC content

Cannabinoids inhibit human keratinocyte proliferation through a non-CB1/CB2 mechanism and have a potential therapeutic value in the treatment of psoriasis

Background: Cannabinoids from cannabis (Cannabis sativa) are anti-inflammatory and have inhibitory effects on the proliferation of a number of tumorigenic cell lines, some of which are mediated via cannabinoid receptors. Cannabinoid (CB) receptors are present in human skin and anandamide, an endogenous CB receptor ligand, inhibits epidermal keratinocyte differentiation. Psoriasis is an inflammatory disease also characterised in part by epidermal keratinocyte hyper-proliferation. Objective: We investigated the plant cannabinoids Delta-9 tetrahydrocannabinol, cannabidiol, cannabinol and cannabigerol for their ability to inhibit the proliferation of a hyper-proliferating human keratinocyte cell line and for any involvement of cannabinoid receptors. Methods: A keratinocyte proliferation assay was used to assess the effect of treatment with cannabinoids. Cell integrity and metabolic competence confirmed using lactate-dehydrogenase and adenosine tri-phosphate assays. To determine the involvement of the receptors, specific agonist and antagonist were used in conjunction with some phytocannabinoids. Western blot and RT-PCR analysis confirmed presence of CB1 and CB2 receptors. Results: The cannabinoids tested all inhibited keratinocyte proliferation in a concentration-dependent manner. The selective CB2 receptor agonists JWH015 and BML190 elicited only partial inhibition, the non-selective CB agonist HU210 produced a concentration-dependent response, the activity of theses agonists were not blocked by either C81 /C82 antagonists. Conclusion: The results indicate that while CB receptors may have a circumstantial role in keratinocyte proliferation, they do not contribute significantly to this process. Our results show that cannabinoids inhibit keratinocyte proliferation, and therefore support a potential role for cannabinoids in the treatment of psoriasis. (c) 2006 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Phytocannabinoids as novel therapeutic agents in CNS disorders

The Cannabis sativa herb contains over 100 phytocannabinoid (pCB) compounds and has been used for thousands of years for both recreational and medicinal purposes. In the past two decades, characterisation of the body's endogenous cannabinoid (CB) (endocannabinoid, eCB) system (ECS) has highlighted activation of central CB1 receptors by the major pCB, Δ9-tetrahydrocannabinol (Δ9-THC) as the primary mediator of the psychoactive, hyperphagic and some of the potentially therapeutic properties of ingested cannabis. Whilst Δ9-THC is the most prevalent and widely studied pCB, it is also the predominant psychotropic component of cannabis, a property that likely limits its widespread therapeutic use as an isolated agent. In this regard, research focus has recently widened to include other pCBs including cannabidiol (CBD), cannabigerol (CBG), Δ9tetrahydrocannabivarin (Δ9-THCV) and cannabidivarin (CBDV), some of which show potential as therapeutic agents in preclinical models of CNS disease. Moreover, it is becoming evident that these non-Δ9-THC pCBs act at a wide range of pharmacological targets, not solely limited to CB receptors. Disorders that could be targeted include epilepsy, neurodegenerative diseases, affective disorders and the central modulation of feeding behaviour. Here, we review pCB effects in preclinical models of CNS disease and, where available, clinical trial data that support therapeutic effects. Such developments may soon yield the first non-Δ9-THC pCB-based medicines.

Cannabidivarin-rich cannabis extracts are anticonvulsant in mouse and rat via a CB 1 receptor-independent mechanism

BACKGROUND AND PURPOSE Epilepsy is the most prevalent neurological disease and is characterized by recurrent seizures. Here, we investigate (i) the anticonvulsant profiles of cannabis-derived botanical drug substances (BDSs) rich in cannabidivarin (CBDV) and containing cannabidiol (CBD) in acute in vivo seizure models and (ii) the binding of CBDV BDSs and their components at cannabinoid CB 1 receptors. EXPERIMENTAL APPROACH The anticonvulsant profiles of two CBDV BDSs (50–422 mg·kg −1 ) were evaluated in three animal models of acute seizure. Purified CBDV and CBD were also evaluated in an isobolographic study to evaluate potential pharmacological interactions. CBDV BDS effects on motor function were also investigated using static beam and grip strength assays. Binding of CBDV BDSs to cannabinoid CB 1 receptors was evaluated using displacement binding assays. KEY RESULTS CBDV BDSs exerted significant anticonvulsant effects in the pentylenetetrazole (≥100 mg·kg −1 ) and audiogenic seizure models (≥87 mg·kg −1 ), and suppressed pilocarpine-induced convulsions (≥100 mg·kg −1 ). The isobolographic study revealed that the anticonvulsant effects of purified CBDV and CBD were linearly additive when co-administered. Some motor effects of CBDV BDSs were observed on static beam performance; no effects on grip strength were found. The Δ 9 -tetrahydrocannabinol and Δ 9 -tetrahydrocannabivarin content of CBDV BDS accounted for its greater affinity for CB 1 cannabinoid receptors than purified CBDV. CONCLUSIONS AND IMPLICATIONS CBDV BDSs exerted significant anticonvulsant effects in three models of seizure that were not mediated by the CB 1 cannabinoid receptor and were of comparable efficacy with purified CBDV. These findings strongly support the further clinical development of CBDV BDSs for the treatment of epilepsy.

Voltage-gated sodium (NaV) channel blockade by plant cannabinoids does not confer anticonvulsant effects per se

Cannabidiol (CBD) is a non-psychoactive, well-tolerated, anticonvulsant plant cannabinoid, although its mechanism(s) of seizure suppression remains unknown. Here, we investigate the effect of CBD and the structurally similar cannabinoid, cannabigerol (CBG), on voltage-gated Na+ (NaV) channels, a common anti-epileptic drug target. CBG’s anticonvulsant potential was also assessed in vivo. CBD effects on NaV channels were investigated using patch-clamp recordings from rat CA1 hippocampal neurons in brain slices, human SH-SY5Y (neuroblastoma) cells and mouse cortical neurons in culture. CBG effects were also assessed in SH-SY5Y cells and mouse cortical neurons. CBD and CBG effects on veratridine-stimulated human recombinant NaV1.1, 1.2 or 1.5 channels were assessed using a membrane potential-sensitive fluorescent dye high-throughput assay. The effect of CBG on pentyleneterazole-induced (PTZ) seizures was assessed in rat. CBD (10M) blocked NaV currents in SH-SY5Y cells, mouse cortical neurons and recombinant cell lines, and affected spike parameters in rat CA1 neurons; CBD also significantly decreased membrane resistance. CBG blocked NaV to a similar degree to CBD in both SH-SY5Y and mouse recordings, but had no effect (50-200mg/kg) on PTZ-induced seizures in rat. CBD and CBG are NaV channel blockers at micromolar concentrations in human and murine neurons and recombinant cells. In contrast to previous reports investigating CBD, CBG had no effect upon PTZ-induced seizures in rat, indicating that NaV blockade per se does not correlate with anticonvulsant effects.

Cannabinoids and epilepsy

Cannabis has been used for centuries to treat seizures. Recent anecdotal reports, accumulating animal model data, and mechanistic insights have raised interest in cannabis-based antiepileptic therapies. In this study, we review current understanding of the endocannabinoid system, characterize the pro- and anticonvulsive effects of cannabinoids [e.g., Δ9-tetrahydrocannabinol and cannabidiol (CBD)], and high-light scientific evidence from pre-clinical and clinical trials of cannabinoids in epilepsy. These studies suggest that CBD avoids the psychoactive effects of the endocannabinoid system to provide a well-tolerated, promising therapeutic for the treatment of seizures, while whole-plant cannabis can both contribute to and reduce seizures. Finally, we discuss results from a new multicenter, open-label study using CBD in a population with treatment-resistant epilepsy. In all, we seek to evaluate our current understanding of cannabinoids in epilepsy and guide future basic science and clinical studies.