SciCombinator

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Concept: Cannabinoids

309

Hair analysis for cannabinoids is extensively applied in workplace drug testing and in child protection cases, although valid data on incorporation of the main analytical targets, ∆9-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-THC (THC-COOH), into human hair is widely missing. Furthermore, ∆9-tetrahydrocannabinolic acid A (THCA-A), the biogenetic precursor of THC, is found in the hair of persons who solely handled cannabis material. In the light of the serious consequences of positive test results the mechanisms of drug incorporation into hair urgently need scientific evaluation. Here we show that neither THC nor THCA-A are incorporated into human hair in relevant amounts after systemic uptake. THC-COOH, which is considered an incontestable proof of THC uptake according to the current scientific doctrine, was found in hair, but was also present in older hair segments, which already grew before the oral THC intake and in sebum/sweat samples. Our studies show that all three cannabinoids can be present in hair of non-consuming individuals because of transfer through cannabis consumers, via their hands, their sebum/sweat, or cannabis smoke. This is of concern for e.g. child-custody cases as cannabinoid findings in a child’s hair may be caused by close contact to cannabis consumers rather than by inhalation of side-stream smoke.

Concepts: Cannabinoid receptor, Cannabis, Cannabinoid, Cannabidiol, Cannabinoids, Recreational drug use, Raphael Mechoulam

176

The psychoactive component of the cannabis resin and flowers, delta9-tetrahydrocannabinol (THC), was first isolated in 1964, and at least 70 other structurally related ‘phytocannabinoid’ compounds have since been identified. The serendipitous identification of a G-protein-coupled cannabinoid receptor at which THC is active in the brain heralded an explosion in cannabinoid research. Elements of the endocannabinoid system (ECS) comprise the cannabinoid receptors, a family of nascent lipid ligands, the ‘endocannabinoids’ and the machinery for their biosynthesis and metabolism. The function of the ECS is thus defined by modulation of these receptors, in particular, by two of the best-described ligands, 2-arachidonoyl glycerol and anandamide (arachidonylethanolamide). Research on the ECS has recently aroused enormous interest not only for the physiological functions, but also for the promising therapeutic potentials of drugs interfering with the activity of cannabinoid receptors. Many of the former relate to stress-recovery systems and to the maintenance of homeostatic balance. Among other functions, the ECS is involved in neuroprotection, modulation of nociception, regulation of motor activity, neurogenesis, synaptic plasticity and the control of certain phases of memory processing. In addition, the ECS acts to modulate the immune and inflammatory responses and to maintain a positive energy balance. This theme issue aims to provide the reader with an overview of ECS pharmacology, followed by discussions on the pivotal role of this system in the modulation of neurogenesis in the developing and adult organism, memory processes and synaptic plasticity, as well as in pathological pain and brain ageing. The volume will conclude with discussions that address the proposed therapeutic applications of targeting the ECS for the treatment of neurodegeneration, pain and mental illness.

Concepts: Receptor, Cannabinoid receptor, Tetrahydrocannabinol, Cannabis, Cannabidiol, Cannabinoids, Anandamide

68

Endogenous cannabinoids (endocannabinoids) are small molecules biosynthesized from membrane glycerophospholipid. Anandamide (AEA) is an endogenous intestinal cannabinoid that controls appetite and energy balance by engagement of the enteric nervous system through cannabinoid receptors. Here, we uncover a role for AEA and its receptor, cannabinoid receptor 2 (CB2), in the regulation of immune tolerance in the gut and the pancreas. This work demonstrates a major immunological role for an endocannabinoid. The pungent molecule capsaicin (CP) has a similar effect as AEA; however, CP acts by engagement of the vanilloid receptor TRPV1, causing local production of AEA, which acts through CB2. We show that the engagement of the cannabinoid/vanilloid receptors augments the number and immune suppressive function of the regulatory CX3CR1(hi) macrophages (Mϕ), which express the highest levels of such receptors among the gut immune cells. Additionally, TRPV1(-/-) or CB2(-/-) mice have fewer CX3CR1(hi) Mϕ in the gut. Treatment of mice with CP also leads to differentiation of a regulatory subset of CD4(+) cells, the Tr1 cells, in an IL-27-dependent manner in vitro and in vivo. In a functional demonstration, tolerance elicited by engagement of TRPV1 can be transferred to naïve nonobese diabetic (NOD) mice [model of type 1 diabetes (T1D)] by transfer of CD4(+) T cells. Further, oral administration of AEA to NOD mice provides protection from T1D. Our study unveils a role for the endocannabinoid system in maintaining immune homeostasis in the gut/pancreas and reveals a conversation between the nervous and immune systems using distinct receptors.

Concepts: Immune system, Diabetes mellitus type 1, Diabetes, Immunology, Receptor, Cannabinoid receptor, Cannabinoids, Anandamide

57

Natural cannabinoids and their synthetic substitutes are the most widely used recreational drugs. Numerous clinical cases describe acute toxic symptoms and neurological consequences following inhalation of the mixture of synthetic cannabinoids known as “Spice.” Here we report that an intraperitoneal administration of the natural cannabinoid Δ(9)-tetrahydrocannabinol (10 mg/kg), one of the main constituent of marijuana, or the synthetic cannabinoid JWH-018 (2.5 mg/kg) triggered electrographic seizures in mice, recorded by electroencephalography and videography. Administration of JWH-018 (1.5, 2.5 and 5 mg/kg) increased seizure spikes dose-dependently. Pretreatment of mice with AM-251 (5 mg/kg), a cannabinoid receptor 1-selective antagonist, completely prevented cannabinoid-induced seizures. These data imply that abuse of cannabinoids can be dangerous and represents an emerging public health threat. Additionally, our data strongly suggest that AM-251 could be used as a crucial prophylactic therapy for cannabinoid-induced seizures or similar life-threatening conditions.

Concepts: Electroencephalography, Cannabinoid receptor, Cannabis, Cannabinoid, Cannabinoids, Recreational drug use, HU-210

57

Increased medical and legal cannabis intake is accompanied by greater use of cannabis vaporization and more cases of driving under the influence of cannabis. Although simultaneous Δ(9)-tetrahydrocannabinol (THC) and alcohol use is frequent, potential pharmacokinetic interactions are poorly understood. Here we studied blood and plasma vaporized cannabinoid disposition, with and without simultaneous oral low-dose alcohol.

Concepts: Cannabinoid receptor, Cannabis, Cannabinoid, Cannabidiol, Cannabinoids, Vaporizer, Raphael Mechoulam

51

Recent analysis of the cannabinoid content of cannabis plants suggests a shift towards use of high potency plant material with high levels of Δ(9)-tetrahydrocannabinol (THC) and low levels of other phytocannabinoids, particularly cannabidiol (CBD). Use of this type of cannabis is thought by some to predispose to greater adverse outcomes on mental health and fewer therapeutic benefits. Australia has one of the highest per capita rates of cannabis use in the world yet there has been no previous systematic analysis of the cannabis being used. In the present study we examined the cannabinoid content of 206 cannabis samples that had been confiscated by police from recreational users holding 15 g of cannabis or less, under the New South Wales “Cannabis Cautioning” scheme. A further 26 “Known Provenance” samples were analysed that had been seized by police from larger indoor or outdoor cultivation sites rather than from street level users. An HPLC method was used to determine the content of 9 cannabinoids: THC, CBD, cannabigerol (CBG), and their plant-based carboxylic acid precursors THC-A, CBD-A and CBG-A, as well as cannabichromene (CBC), cannabinol (CBN) and tetrahydrocannabivarin (THC-V). The “Cannabis Cautioning” samples showed high mean THC content (THC+THC-A = 14.88%) and low mean CBD content (CBD+CBD-A = 0.14%). A modest level of CBG was detected (CBG+CBG-A = 1.18%) and very low levels of CBC, CBN and THC-V (<0.1%). "Known Provenance" samples showed no significant differences in THC content between those seized from indoor versus outdoor cultivation sites. The present analysis echoes trends reported in other countries towards the use of high potency cannabis with very low CBD content. The implications for public health outcomes and harm reduction strategies are discussed.

Concepts: Cannabinoid receptor, Tetrahydrocannabinol, Cannabis, Cannabinoid, Cannabidiol, Cannabinoids, New South Wales

42

Cannabidiol (CBD) is a phytocannabinoid with therapeutic properties for numerous disorders exerted through molecular mechanisms that are yet to be completely identified. CBD acts in some experimental models as an anti-inflammatory, anticonvulsant, anti-oxidant, anti-emetic, anxiolytic and antipsychotic agent, and is therefore a potential medicine for the treatment of neuroinflammation, epilepsy, oxidative injury, vomiting and nausea, anxiety and schizophrenia, respectively. The neuroprotective potential of CBD, based on the combination of its anti-inflammatory and anti-oxidant properties, is of particular interest and is presently under intense preclinical research in numerous neurodegenerative disorders. In fact, CBD combined with Δ(9) -tetrahydrocannabinol is already under clinical evaluation in patients with Huntington’s disease to determine its potential as a disease-modifying therapy. The neuroprotective properties of CBD do not appear to be exerted by the activation of key targets within the endocannabinoid system for plant-derived cannabinoids like Δ(9) -tetrahydrocannabinol, i.e. CB(1) and CB(2) receptors, as CBD has negligible activity at these cannabinoid receptors, although certain activity at the CB(2) receptor has been documented in specific pathological conditions (i.e. damage of immature brain). Within the endocannabinoid system, CBD has been shown to have an inhibitory effect on the inactivation of endocannabinoids (i.e. inhibition of FAAH enzyme), thereby enhancing the action of these endogenous molecules on cannabinoid receptors, which is also noted in certain pathological conditions. CBD acts not only through the endocannabinoid system, but also causes direct or indirect activation of metabotropic receptors for serotonin or adenosine, and can target nuclear receptors of the PPAR family and also ion channels.

Concepts: Receptor, Neurology, Serotonin, Cannabinoid receptor, Cannabis, Cannabinoid, Cannabidiol, Cannabinoids

35

The CB2 cannabinoid agonist LY2828360 lacked both toxicity and efficacy in a clinical trial for osteoarthritis. Whether LY2828360 suppresses neuropathic pain has not been reported and its signaling profile is unknown. In vitro, LY2828360 was a slowly acting but efficacious G protein-biased CB2 agonist, inhibiting cAMP accumulation and activating ERK1/2 signaling while failing to recruit arrestin, activate inositol phosphate signaling or internalize CB2 receptors. In wildtype (WT) mice, LY2828360 (3 mg/kg/day i.p. x 12 days) suppressed chemotherapy-induced neuropathic pain produced by paclitaxel without producing tolerance. Anti-allodynic efficacy of LY2828360 was absent in CB2KO mice. Morphine (10 mg/kg/day i.p. x 12 days) tolerance developed in CB2KO mice but not in WT mice with a history of LY2828360 treatment (3 mg/kg/day i.p. x 12 days). LY2828360-induced anti-allodynic efficacy was preserved in WT mice previously rendered tolerant to morphine (10 mg/kg/day i.p. x 12 days) but absent in morphine-tolerant CB2KO mice. Coadministration of LY2828360 (0.1 mg/kg/day i.p. x 12 days) with morphine (10 mg/kg/day x 12 days) blocked morphine tolerance in WT but not CB2KO mice. WT mice that received LY2828360 coadministered with morphine exhibited a trend (p=0.055) towards fewer naloxone-precipitated jumps compared to CB2KO mice. In conclusion, LY2828360 is a slowly signaling, G protein-biased CB2 agonist that attenuates chemotherapy-induced neuropathic pain without producing tolerance, and may prolong effective opioid analgesia while reducing opioid dependence. LY2828360 may be useful as a first line treatment in chemotherapy-induced neuropathic pain and may be highly efficacious in neuropathic pain states that are refractive to opioid analgesics.

Concepts: Opioid, Pain, Morphine, Cannabinoid receptor, Analgesic, Cannabis, Buprenorphine, Cannabinoids

31

The endocannabinoid system plays a key role in regulating a variety of physiological processes such as appetite control and energy balance, pain perception, and immune responses. Recent studies have implicated the endocannabinoid system in the regulation of bone cell activity and bone remodeling. These studies showed that endogenous cannabinoid ligands, cannabinoid receptors, and the enzymes responsible for ligand synthesis and breakdown all play important roles in bone mass and in the regulation of bone disease. These findings suggest that the endocannabinoid pathway could be of value as a therapeutic target for the prevention and treatment of bone diseases. Here, we review the role of the skeletal endocannabinoid system in the regulation of bone remodeling in health and disease.

Concepts: Medicine, Cannabinoids

28

Herbal smoking mixtures which are sold as incense or potpourri and often referred to as ‘Spice’ are actually inactive plant matter adulterated with alkylamino indole based synthetic cannabinoids such as JWH-018 and JWH-073. Due to the inclusion of five synthetic cannabinoids, including JWH-018 and JWH-073, as Schedule I drugs by the Drug Enforcement Agency (DEA) in March 2011, it has become necessary for forensic laboratories to develop analytical methods to test for the presence of metabolites of synthetic cannabinoids. When a new analyte of interest emerges, most laboratories strive to develop a sample preparation procedure and validate an analytical method as quickly as possible and therefore, rely on effective but time consuming traditional protocols such as solid phase and liquid-liquid extraction. This research focuses on the examination of all aspects of sample preparation and analytical method development to streamline the analysis of four urinary metabolites of JWH-018 and JWH-073. A detailed evaluation of the β-glucuronide hydrolysis step lead to the reduction of time required for hydrolysis from 1h at 50°C to only 10min at room temperature. By utilizing a salting-out assisted liquid-liquid extraction (SALLE) in place of traditional liquid-liquid extraction with a volatile solvent, processing time was saved and waste was reduced. The analysis run time was also shortened to one-third of a typical published run time by utilizing UPLC with isocratic conditions in place of conventional HPLC running a gradient method.

Concepts: Solubility, Benzene, Analytical chemistry, Diethyl ether, Cannabinoid, Cannabinoids, HU-210, Drug Enforcement Administration