Tag Archives: CB1

Therapeutic Potential of Non-Psychotropic Cannabidiol in Ischemic Stroke.

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“Cannabis contains the psychoactive component delta⁸-tetrahydrocannabinol (delta⁸-THC), and the non-psychoactive components cannabidiol (CBD), cannabinol, and cannabigerol.

It is well-known that delta⁸-THC and other cannabinoid CB₁ receptor agonists are neuroprotective during global and focal ischemic injury.

Additionally, delta⁸-THC also mediates psychological effects through the activation of the CB₁ receptor in the central nervous system.

In addition to the CB₁ receptor agonists, cannabis also contains therapeutically active components which are CB₁ receptor independent.

Of the CB₁ receptor-independent cannabis, the most important is CBD.

In the past five years, an increasing number of publications have focused on the discovery of the anti-inflammatory, anti-oxidant, and neuroprotective effects of CBD.

In particular, CBD exerts positive pharmacological effects in ischemic stroke and other chronic diseases, including Parkinson’s disease, Alzheimer’s disease, and rheumatoid arthritis.

The cerebroprotective action of CBD is CB₁ receptor-independent, long-lasting, and has potent anti-oxidant activity. Importantly, CBD use does not lead to tolerance.

In this review, we will discuss the therapeutic possibility of CBD as a cerebroprotective agent, highlighting recent pharmacological advances, novel mechanisms, and therapeutic time window of CBD in ischemic stroke.”

https://www.ncbi.nlm.nih.gov/pubmed/27713349

NSAIDs, Opioids, Cannabinoids and the Control of Pain by the Central Nervous System.

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“Nonsteroidal anti-inflammatory drugs (NSAIDs) act upon peripheral tissues and upon the central nervous system to produce analgesia. A major central target of NSAIDs is the descending pain control system. The rostral structures of the descending pain control system send impulses towards the spinal cord and regulate the transmission of pain messages. Key structures of the descending pain control system are the periaqueductal gray matter (PAG) and the rostral ventromedial region of the medulla (RVM), both of which are critical targets for endogenous opioids and opiate pharmaceuticals. NSAIDs also act upon PAG and RVM to produce analgesia and, if repeatedly administered, induce tolerance to themselves and cross-tolerance to opioids. Experimental evidence shows that this is due to an interaction of NSAIDs with endogenous opioids along the descending pain control system. Analgesia by NSAIDs along the descending pain control system also requires an activation of the CB1 endocannabinoid receptor. Several experimental approaches suggest that opioids, NSAIDs and cannabinoids in PAG and RVM cooperate to decrease GABAergic inhibition and thus enhance the descending flow of impulses that inhibit pain.”

 https://www.ncbi.nlm.nih.gov/pubmed/27713305

Leveraging allostery to improve G protein-coupled receptor (GPCR)-directed therapeutics: cannabinoid receptor 1 as a discovery target.

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“Allosteric modulators of G-protein coupled receptors (GPCRs) hold the promise of improved pharmacology and safety over typical orthosteric GPCR ligands.

These features are particularly relevant to the cannabinoid receptor 1 (CB1R) GPCR, since typical orthosteric CB1R ligands are associated with adverse events that limit their translational potential.

Areas covered: The contextual basis for applying allostery to CB1R is considered from pharmacological, drug-discovery, and medicinal standpoints.

Rational design of small-molecule CB1R allosteric modulators as potential pharmacotherapeutics would be greatly facilitated by direct experimental characterization of structure-function correlates underlying the biological activity of chemically-diverse CB1R allosteric modulators, CB1R allosteric ligand-binding binding pockets, and amino acid contact residues critical to allosteric ligand engagement and activity.

In these regards, designer covalent probes exhibiting well-characterized molecular pharmacology as CB1R allosteric modulators are emerging as valuable molecular reporters enabling experimental interrogation of CB1R allosteric site(s) and informing the design of new CB1R agents as drugs.

Expert opinion: Synthesis and pharmacological profiling of CB1R allosteric ligands will continue to provide valuable insights into CB1R structure-function correlates. The resulting data should expand the repertoire of novel agents capable of exerting therapeutic benefit by modulating CB1R-dependent signaling.”

 https://www.ncbi.nlm.nih.gov/pubmed/27712124

Cannabinoid CB1 receptors in distinct circuits of the extended amygdala determine fear responsiveness to unpredictable threat.

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“The brain circuits underlying behavioral fear have been extensively studied over the last decades.

Here, we show that the endocannabinoid system acting in synaptic circuits of the extended amygdala can explain the fear response profile during exposure to unpredictable threat.

Using fear training with predictable or unpredictable cues in mice, combined with local and cell-type-specific deficiency and rescue of cannabinoid type 1 (CB1) receptors, we found that presynaptic CB1 receptors on distinct amygdala projections to bed nucleus of the stria terminalis (BNST) are both necessary and sufficient for the shift from phasic to sustained fear in response to an unpredictable threat.

These results thereby identify the causal role of a defined protein in a distinct brain pathway for the temporal development of a sustained state of anxious apprehension during unpredictability of environmental influences, reminiscent of anxiety symptoms in humans.”

https://www.ncbi.nlm.nih.gov/pubmed/27698427

Anandamide Suppresses Proinflammatory T Cell Responses In Vitro through Type-1 Cannabinoid Receptor-Mediated mTOR Inhibition in Human Keratinocytes.

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“The endocannabinoid system comprises cannabinoid receptors 1 and 2 (CB1 and CB2), their endogenous ligands, anandamide (AEA) and 2-arachidonoylglycerol, and metabolic enzymes of these ligands.

The endocannabinoid system has recently been implicated in the regulation of various pathophysiological processes of the skin that include immune competence and/or tolerance of keratinocytes, the disruption of which might promote the development of skin diseases.

Recent evidence showed that CB1 in keratinocytes limits the secretion of proinflammatory chemokines, suggesting that this receptor might also regulate T cell dependent inflammatory diseases of the skin.

In this article, we sought to investigate the cytokine profile of IFN-γ-activated keratinocytes, and found that CB1 activation by AEA suppressed production and release of signature TH1- and TH17-polarizing cytokines, IL-12 and IL-23, respectively. We also set up cocultures between a conditioned medium of treated keratinocytes and naive T cells to disclose the molecular details that regulate the activation of highly proinflammatory TH1 and TH17 cells.

AEA-treated keratinocytes showed reduced an induction of IFN-γ-producing TH1 and IL-17-producing TH17 cells, and these effects were reverted by pharmacological inhibition of CB1.

Further analyses identified mammalian target of rapamycin as a proinflammatory signaling pathway regulated by CB1, able to promote either IL-12 and IL-23 release from keratinocytes or TH1 and TH17 polarization.

Taken together, these findings demonstrate that AEA suppresses highly pathogenic T cell subsets through CB1-mediated mammalian target of rapamycin inhibition in human keratinocytes.

Thus, it can be speculated that the latter pathway might be beneficial to the physiological function of the skin, and can be targeted toward inflammation-related skin diseases.”

https://www.ncbi.nlm.nih.gov/pubmed/27694494

THC (Δ9-Tetrahydrocannabinol) Exerts Neuroprotective Effect in Glutamate-affected Murine Primary Mesencephalic Cultures Through Restoring Mitochondrial Membrane Potential and Anti-apoptosis Involving CB1 Receptor-dependent Mechanism.

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“Aging-related neurodegenerative diseases, such as Parkinson’s disease (PD) or related disorders, are an increasing societal and economic burden worldwide.

Δ9-Tetrahydrocannabinol (THC) is discussed as a neuroprotective agent in several in vitro and in vivo models of brain injury. However, the mechanisms by which THC exhibits neuroprotective properties are not completely understood.

In the present study, we investigated neuroprotective mechanisms of THC in glutamate-induced neurotoxicity in primary murine mesencephalic cultures, as a culture model for PD.

THC protected dopaminergic neurons and other cell types of primary dissociated cultures from glutamate-induced neurotoxicity.

Moreover, THC significantly counteracted the glutamate-induced mitochondrial membrane depolarization and apoptosis.

In conclusion, THC exerts anti-apoptotic and restores mitochondrial membrane potential via a mechanism dependent on CB1 receptor.

It strengthens the fact that THC has a benefit on degenerative cellular processes occurring, among others, in PD and other neurodegenerative diseases by slowing down the progression of neuronal cell death.”

https://www.ncbi.nlm.nih.gov/pubmed/27654887

http://onlinelibrary.wiley.com/wol1/doi/10.1002/ptr.5712/full

Tetrahydropyrazolo[4,3-c]pyridine derivatives as potent and peripherally selective cannabinoid-1 (CB1) receptor inverse agonists.

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“Peripherally restricted CB1 receptor inverse agonists hold potential as useful therapeutics to treat obesity and related metabolic diseases without causing undesired CNS-mediated adverse effects. We identified a series of tetrahydropyrazolo[4,3-c]pyridine derivatives as potent and highly peripherally selective CB1 receptor inverse agonists. This discovery was achieved by introducing polar functional groups into the molecule, which increase the topological polar surface area and reduce its brain-penetrating ability.”

https://www.ncbi.nlm.nih.gov/pubmed/27671499

“Tetrahydroindazole derivatives as potent and peripherally selective cannabinoid-1 (CB1) receptor inverse agonists. A series of potent and receptor-selective cannabinoid-1 (CB1) receptor inverse agonists has been discovered. Peripheral selectivity of the compounds was assessed by a mouse tissue distribution study, in which the concentrations of a test compound in both plasma and brain were measured. A number of peripherally selective compounds have been identified through this process. Compound 2p was further evaluated in a 3-week efficacy study in the diet-induced obesity (DIO) mouse model. Beneficial effects on plasma glucose were observed from the compound-treated mice.”  https://www.ncbi.nlm.nih.gov/pubmed/27671496

The endocannabinoid anandamide causes endothelium-dependent vasorelaxation in human mesenteric arteries.

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“The endocannabinoid anandamide (AEA) causes vasorelaxation in animal studies.

Although circulating AEA levels are increased in many pathologies, little is known about its vascular effects in humans. The aim of this work was to characterise the effects of AEA in human arteries.

Post hoc analysis of the data set showed that overweight patients and those taking paracetamol had reduced vasorelaxant responses to AEA.

These data show that AEA causes moderate endothelium-dependent, NO-dependent vasorelaxation in human mesenteric arteries via activation of CB1 receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/27633407

The syntheses of isotopically labelled CB-1 antagonists for the treatment of obesity.

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“BMS-725519, BMS-811064, and BMS-812204 are potent and selective central cannabinoid receptor antagonists that have been investigated for the treatment of human obesity. To further understand their biotransformation profiles, radiolabelled and stable-labelled products were required. This paper describes the utility of [14 C]1,1-carbonyldiimidazole as a radiolabelling reagent for the syntheses of carbonyl-labelled [14 C]BMS-725519, [14 C]BMS-811064, and [14 C]BMS-812204. The syntheses of stable-labelled [13 C6 ]BMS-725519 and [13 CD3 13 CD2 ]BMS-812204 synthesized from of [13 C6 ]4-chloroacetophenone and [13 CD3 13 CD2 ]iodoethane, respectively, are also described.”

http://www.ncbi.nlm.nih.gov/pubmed/27624665

High-Intensity Swimming Exercise Decreases Glutamate-Induced Nociception by Activation of G-Protein-Coupled Receptors Inhibiting Phosphorylated Protein Kinase A.

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“Several studies in humans have reported that improved pain control is associated with exercise in a variety of painful conditions, including osteoarthritis, fibromyalgia, and neuropathic pain.

Despite the growing amount of experimental data on physical exercise and nociception, the precise mechanisms through which high-intensity exercise reduces pain remain elusive.

Since the glutamatergic system plays a major role in pain transmission, we firstly analyzed if physical exercise could be able to decrease glutamate-induced nociception through G-protein-coupled receptor (G-PCR) activation.

The second purpose of this study was to examine the effect of exercising upon phosphorylation of protein kinase A (PKA) isoforms induced by intraplantar (i.pl.) glutamate injection in mice.

Our results demonstrate that high-intensity swimming exercise decreases nociception induced by glutamate and that i.pl. or intrathecal injections of cannabinoid, opioid, and adenosine receptor antagonists, AM281, naloxone, and 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), respectively, prevent this effect.

Furthermore, the peripheral A1 and opioid receptors, but not CB1, are also involved in exercise’s effect. We also verified that glutamate injection increases levels of phosphorylated PKA (p-PKA). High-intensity swimming exercise significantly prevented p-PKA increase.

The current data show the direct involvement of the glutamatergic system on the hyponociceptive effect of high-intensity swimming exercise as well as demonstrate that physical exercise can activate multiple intracellular pathways through G-PCR activation, which share the same endogenous mechanism, i.e., inhibition of p-PKA.”

http://www.ncbi.nlm.nih.gov/pubmed/27624384