Tag Archives: CB2

Anti-inflammatory cannabinoids in diet: Towards a better understanding of CB(2) receptor action?

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“The endocannabinoid system is an ancient lipid signaling network which in mammals modulates neuronal functions, inflammatory processes, and is involved in the aetiology of certain human lifestyle diseases, such as Crohn’s disease, atherosclerosis and osteoarthritis.

The system is able to downregulate stress-related signals that lead to chronic inflammation and certain types of pain, but it is also involved in causing inflammation-associated symptoms, depending on the physiological context.

The cannabinoid type-2 (CB2) receptor, which unlike the CB1 receptor does not induce central side effects, has been shown to be a promising therapeutic target. While CB1 receptor antagonists/inverse agonists are of therapeutic value, also CB2 receptor ligands including agonists are of pharmacological interest.

 Although the endocannabinoid system is known to be involved in the regulation of energy homoeostasis and metabolism (mainly via CB1 receptors) there was hitherto no direct link between food intake and cannabinoid receptor activation. Our recent finding that beta-caryophyllene, a ubiquitous lipohilic plant natural product, selectively binds to the CB2 receptor and acts as a full agonist is unexpected…

In the case of the dietary natural product beta-caryophyllene, a full CB2 receptor-selective agonist in vitro, potent anti-inflammatory cannabimimetic effects are observed. Intriguingly, the lowest oral dose tested (5 mg/Kg) of this widespread and apparently non-toxic compound, which is also an FDA-approve food additive, was the most effective. Maybe this strengthens the hypothesis that beta-caryophyllene is indeed a dietary cannabinoid, thus inferring that by eating this compound the endocannabinoid system may be modulated in a beneficial way…”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2633791/

Cannabinoid Receptor 2-Mediated Attenuation of CXCR4-Tropic HIV Infection in Primary CD4+ T Cells

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“Agents that activate cannabinoid receptor pathways have been tested as treatments for cachexia, nausea or neuropathic pain in HIV-1/AIDS patients… Cannabinoid agonists activate the CB1R and CB2R cannabinoid receptors…

Cannabinoid agonists are currently under investigation for the treatment of AIDS-associated cachexia, nausea, and neuropathic pain. One such drug, dronabinol (Δ9-THC; Marinol®), has won Food and Drug Administration (FDA) approval for treatment of HIV-associated anorexia. Additionally, the prescription of smoked or ingested cannabis (marijuana) for treatment of AIDS-related symptoms has been approved…. Despite the use of cannabinoids by HIV/AIDS patients, few studies have investigated the impact of such drugs in regard to viral pathogenesis or immune regulation…

….Indeed, both smoked marijuana and dronabinol were reported to increase total CD4+ T cell number and naïve T cell number over a 21-day period. A decrease in viral load was also observed in these patients. Similarly, in SIV infected rhesus macaques, Δ9-THC exposure reduced viral load and CD4+ T cell depletion, significantly increasing animal survival over an 11 month period.

. Our findings suggest that CB2R activation in CD4+ T cells can inhibit actin reorganization and impair productive infection following cell-free or cell-associated viral acquisition of CXCR4-tropic HIV-1 in resting cells.

Therefore, the clinical use of CB2R agonists in the treatment of AIDS symptoms may also exert beneficial adjunctive antiviral effects against CXCR4-tropic viruses in late stages of HIV-1 infection.

Further study of cannabinoids and other neuroendocrine regulators that selectively modulate immune function may result in the discovery of new anti-viral drugs that can also mitigate AIDS-associated symptoms.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3309010/

Cannabinoid Inhibition of Macrophage Migration to the Trans-Activating (Tat) Protein of HIV-1 Is Linked to the CB2 Cannabinoid Receptor

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“Macrophage-like cells are primary targets for infection by HIV-1…  In the present study, the exogenous cannabinoids δ-9-tetrahydrocannabinol (THC) and (−)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl) cyclohexanol (CP55940) were shown to significantly inhibit migration of human U937 macrophage-like cells to the Tat protein in a concentration-related manner….

Collectively, the pharmacological and biochemical knockdown data indicate that cannabinoid-mediated modulation of macrophage migration to the HIV-1 Tat protein is linked to the CB2 cannabinoid receptor. Furthermore, these results suggest that the CB2 cannabinoid receptor has potential to serve as a therapeutic target for ablation of HIV-1-associated untoward inflammatory response…

,,, the CB2 receptor has the potential to serve as a molecular target for ablating hyperinflammatory responses of macrophage-like cells while avoiding untoward psychotropic effects caused by activation of the CB1 receptor.

 In conclusion, the immunosuppressive and anti-inflammatory properties of select cannabinoids may have profound therapeutic potential in moderating HIV-associated immunopathology, including microglial activation, chemokine/cytokine dysregulation, and monocyte infiltration in the CNS.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2846023/

Attenuation of HIV-1 replication in macrophages by cannabinoid receptor 2 agonists.

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“Previous studies showed that activation of the CB2 can attenuate inflammatory responses and affect HIV-1 infectivity in T cells and microglia. Here, we report that CB2 agonists can also act as immunomodulators on HIV-1-infected macrophages.

   We speculate that these findings indicate that prevention of viral entry is not a central mechanism for CB2-mediated suppression in viral replication.

However, CB2 may affect the HIV-1 replication machinery.

Results from a single-round infection with the pseudotyped virus revealed a marked decrease in HIV-1 LTR activation by the CB2 ligands.

Together, these results indicate that CB2 may offer a means to limit HIV-1 infection in macrophages.”

http://www.ncbi.nlm.nih.gov/pubmed/23463725

The role of the CB1 receptor in the regulation of sleep.

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“During the 1990s, transmembranal proteins in the central nervous system (CNS) that recognize the principal compound of marijuana, the delta-9-tetrahydrocannabinol (Delta9-THC) were described. The receptors were classified as central or peripheral, CB1 and CB2, respectively. To this date, it has been documented the presence in the CNS of specific lipids that bind naturally to the CB1/CB2 receptors.

The family of endogenous cannabinoids or endocannabinoids comprises oleamide, arachidonoylethanolamine, 2-arachidonylglycerol, virodhamine, noladin ether and N-arachidonyldopamine. Pharmacological experiments have shown that those compounds induce cannabimimetic effects. Endocannabinoids are fatty acid derivates that have a variety of biological actions, most notably via activation of the cannabinoid receptors. The endocannabinoids have an active role modulating diverse neurobiological functions, such as learning and memory, feeding, pain perception and sleep generation.

Experimental evidence shows that the administration of Delta9-THC promotes sleep.

 The activation of the CB1 receptor leads to an induction of sleep, this effect is blocked via the selective antagonist.

Since the system of the endogenous cannabinoids is present in several species, including humans, this leads to the speculation of the neurobiological role of the endocannabinoid system on diverse functions such as sleep modulation.

This review discusses the evidence of the system of the endocannabinoids as well as their physiological role in diverse behaviours, including the modulation of sleep.”

http://www.ncbi.nlm.nih.gov/pubmed/18514375

Beneficial effect of the non-psychotropic plant cannabinoid cannabigerol on experimental inflammatory bowel disease.

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“Inflammatory bowel disease (IBD) is an incurable disease which affects millions of people in industrialised countries. Anecdotal and scientific evidence suggest that Cannabis use may have a positive impact in IBD patients.

 Here, we investigated the effect of cannabigerol (CBG), a non-psychotropic Cannabis-derived cannabinoid, in a murine model of colitis…

  In conclusion, CBG attenuated murine colitis, reduced nitric oxide production in macrophages (effect being modulated by the CB(2) receptor) and reduced ROS formation in intestinal epithelial cells.

CBG could be considered for clinical experimentation in IBD patients.”

http://www.ncbi.nlm.nih.gov/pubmed/23415610

Activation of Cannabinoid CB2 Receptor-Mediated AMPK/CREB Pathway Reduces Cerebral Ischemic Injury.

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“The type 2 cannabinoid receptor (CB2R) was recently shown to mediate neuroprotection in ischemic injury. However, the role of CB2Rs in the central nervous system, especially neuronal and glial CB2Rs in the cortex, remains unclear. We, therefore, investigated anti-ischemic mechanisms of cortical CB2R activation in various ischemic models….

  Collectively, these data demonstrate that cortical CB2R activation by TC (trans-caryophyllene, a CB2R agonist,), ameliorates ischemic injury, potentially through modulation of AMPK/CREB signaling, and suggest that cortical CB2Rs might serve as a putative therapeutic target for cerebral ischemia.”

http://www.ncbi.nlm.nih.gov/pubmed/23414569

Modulation of Cannabinoid Receptor Activation as a Neuroprotective Strategy for EAE and Stroke

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“These results provide evidence that alteration of the activation patterns of the various cannabinoid receptors warrant consideration for future therapeutic strategies.

Interest in the medicinal use of Cannabis sativa (marijuana) has a long historical record, extending back thousands of years. In comparison to the extensive history for medicinal applications of marijuana, the existence of an “endocannabinoid system”, with important homeostatic and pathologic functions, has only recently gained appreciation. The endocannabinoid system consists of endogenously produced cannabinoids, their receptors, and the enzymes responsible for their synthesis and degradation…

Although used in ancient Greece, Rome, and China for therapeutic purposes, concern about the use of cannabinoids as a drug of abuse has dampened interest in developing the potential therapeutic benefits of these compounds. However, a better understanding of the biologic effects has led recently to an upsurge in interest for the development of therapeutic drugs through modification of the endocannabinoid system. An additional incentive was provided by the development of synthetic cannabinoid analogs and specific inhibitors of cannabinoid receptors. Several excellent reviews cover the therapeutic potential of cannabinoids….

The present review is focused on the effects of CB2 receptor activation in models of multiple sclerosis (experimental autoimmune encephalomyelitis) and stroke (middle cerebral occlusion/reperfusion).

In summary, selective CB2 receptor agonists and CB1 receptor antagonists have significant potential for neuroprotection in animal models of two devastating diseases that currently lack effective treatment options.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2855650/

[Expression of cannabinoid receptor 2 in squamous cell carcinoma].

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“The expression of CB2 protein and mRNA levels were detected in normal human skin and squamous cell carcinoma… Both the normal skin and squamous cell carcinoma expressed CB2, which was localized mainly in the basal cell layer and prickle cell layer in human skin with low expressions in the subcutaneous tissue.

 

CONCLUSION:

Squamous cell carcinoma over-expresses CB2 at both the protein and mRNA levels. High expression of CB2 in squamous cell carcinoma suggests an important role of CB2 in the tumorigenesis and development of squamous cell carcinoma.”

http://www.ncbi.nlm.nih.gov/pubmed/20335147