Tag Archives: CB2

Cannabichromene is a cannabinoid CB2 receptor agonist.

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British Journal of Pharmacology banner“Cannabichromene (CBC) is one of the most abundant phytocannabinoids in Cannabis spp. It has modest anti-nociceptive and anti-inflammatory effects and potentiates some effects of Δ9 – tetrahydrocannabinol (THC) in vivo. How CBC exerts these effects is poorly defined and there is little information about its efficacy at cannabinoid receptors. We sought to determine the functional activity of CBC at CB1 and CB2 receptors.

KEY RESULTS:

CBC activated CB2 but not CB1 receptors to produce a hyperpolarization of AtT20 cells. This activation was inhibited by a CB2 antagonist AM630, and sensitive to pertussis toxin. Application of CBC reduced activation of CB2 receptors (but not CB1 receptors) by subsequent co-application of CP55,940, an efficacious CB1 and CB2 agonist. Continuous CBC application induced loss of cell surface CB2 receptors and desensitisation of the CB2-induced hyperpolarization.

CONCLUSIONS AND IMPLICATIONS:

CBC is a selective CB2 receptor agonist displaying higher efficacy than THC in hyperpolarising AtT20 cells. CBC can also recruit CB2 receptor regulatory mechanisms. CBC may contribute to the potential therapeutic effectiveness of some cannabis preparations, potentially through CB2-mediated modulation of inflammation.”

https://www.ncbi.nlm.nih.gov/pubmed/31368508

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14815

Quetiapine induces myocardial necroptotic cell death through bidirectional regulation of cannabinoid receptors.

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Toxicology Letters

“Quetiapine is a common atypical antipsychotic used to treat mental disorders such as schizophrenia, bipolar disorder, and major depressive disorder. There has been increasing number of reports describing its cardiotoxicity. However, the molecular mechanisms underlying quetiapine-induced myocardial injury remain largely unknown.

Herein, we reported a novel cell death type, quetiapine-induced necroptosis, which accounted for quetiapine cardiotoxicity in mice and proposed novel therapeutic strategies.

Quetiapine-treated hearts showed inflammatory infiltration and evident fibrosis after 21-day continuous injection. The specific increases of protein levels of RIP3, MLKL and the phosphorylation of MLKL showed that quetiapine-induced necroptotic cell death both in vivo and in vitro. Pharmacologic blockade of necroptosis using its specific inhibitor Necrostatin-1 attenuated quetiapine-induced myocardial injury in mice.

In addition, quetiapine imbalanced the endocannabinoid system and caused opposing effects on two cannabinoid receptors (CB1R and CB2R).

Specific antagonists of CB1R (AM 281, Rimonabant), but not its agonist ACEA significantly ameliorated the heart histopathology induced by chronic quetiapine exposure. By contrast, specific agonists of CB2R (JWH-133, AM 1241), but not its antagonist AM 630 exerted beneficial roles against quetiapine cardiotoxicity.

The protective agents (AM 281, Rimonabant, AM 1241, and JWH-133) consistently inactivated the quetiapine-induced necroptosis signaling. Quetiapine bidirectionally regulates cannabinoid receptors and induces myocardial necroptosis, leading to cardiac toxic effects.

Therefore, pharmacologic inhibition of CB1R or activation of CB2R represents promising therapeutic strategies against quetiapine-induced cardiotoxicity.”

https://www.ncbi.nlm.nih.gov/pubmed/31220554

https://www.sciencedirect.com/science/article/pii/S0378427419301766?via%3Dihub

Alcohol-induced conditioned place preference is modulated by CB2 cannabinoid receptors and modifies levels of endocannabinoids in the mesocorticolimbic system.

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Pharmacology Biochemistry and Behavior

“The endocannabinoid (eCB) system is a particularly important neuronal mechanism implicated in alcohol use disorders. Animal models are key to broadening our knowledge of the neurobiological mechanisms underlying alcohol dependence.

This study has two main aims: i) to assess how eCB levels in different brain areas are modified by alcohol-induced conditioning place preference (CPP), and ii) to study how cannabinoid type 2 receptor (CB2R) is involved in alcohol-rewarding properties, using pharmacological manipulation in C57BL/6 mice.

Our results suggest that the eCB system is dysregulated throughout the mesocorticolimbic system by repeated alcohol exposure during the CPP paradigm, and that levels of anandamide (AEA) and several other N-acylethanolamines are markedly decreased in the medial prefrontal cortex and ventral midbrain of alcohol-CPP mice.

We also observed that the administering an antagonist/inverse agonist of the CB2R (AM630) during the acquisition phase of CPP reduced the rewarding effects of alcohol. However, activating CB2R signalling using the agonist JWH133 seems to reduce both alcohol- and food-rewarding behaviours. Therefore, our findings indicate that the rewarding effects of alcohol are related to its disruptive effect on AEA and other N-acylethanolamine signalling pathways.

Thus, pharmacological manipulation of CB2R is an interesting candidate treatment for alcohol use disorders.”

https://www.ncbi.nlm.nih.gov/pubmed/31220547

https://www.sciencedirect.com/science/article/pii/S0091305719300656?via%3Dihub

Opioid-Sparing Effects of Cannabinoids on Morphine Analgesia: Participation of CB1 and CB2 Receptors.

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British Journal of Pharmacology banner“Much of the opioid epidemic arose from abuse of prescription opioid drugs.

This study sought to determine if the combination of a cannabinoid with an opioid could produce additive or synergistic effects on pain, allowing reduction in the opioid dose needed for maximal analgesia.

CONCLUSIONS AND IMPLICATIONS:

The ability of a cannabinoid to produce an additive or synergistic effect on analgesia when combined with morphine varies with the pain assay and may be mediated by CB1 or CB2 receptors. These results hold the promise of using cannabinoids to reduce the dose of opioids for analgesia in certain pain conditions.”

https://www.ncbi.nlm.nih.gov/pubmed/31218677

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14769

Cannabidiol inhibits sucrose self-administration by CB1 and CB2 receptor mechanisms in rodents.

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Addiction Biology banner

“A growing number of studies suggest therapeutic applications of cannabidiol (CBD), a recently U.S. Food and Drug Administration (FDA)-approved medication for epilepsy, in treatment of many other neuropsychological disorders. However, pharmacological action and the mechanisms by which CBD exerts its effects are not fully understood.

Here, we examined the effects of CBD on oral sucrose self-administration in rodents and explored the receptor mechanisms underlying CBD-induced behavioral effects using pharmacological and transgenic approaches.

Systemic administration of CBD produced a dose-dependent reduction in sucrose self-administration in rats and in wild-type (WT) and CB1-/- mice but not in CB2-/- mice. CBD appeared to be more efficacious in CB1-/- mice than in WT mice.

Similarly, pretreatment with AM251, a CB1R antagonist, potentiated, while AM630, a selective CB2R antagonist, blocked CBD-induced reduction in sucrose self-administration, suggesting the involvement of CB1 and CB2 receptors.

Taken together, the present findings suggest that CBD may have therapeutic potential in reducing binge eating and the development of obesity.”

https://www.ncbi.nlm.nih.gov/pubmed/31215752

https://onlinelibrary.wiley.com/doi/abs/10.1111/adb.12783

The oncogenic role of CB2 in the progression of non-small-cell lung cancer.

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Biomedicine & Pharmacotherapy

“Several studies have verified the important role of cannabinoid and cannabinoid receptor agonists in tumor progression. However, little is known about the precise role of CB2 expression level in the progression of non-small-cell lung cancer (NSCLC).

The expression of CB2 in NSCLC tissues and corresponding paracancerous tissues was examined using immunohistochemical staining assay.

CONCLUSION:

Our data suggested that targeting CB2 may inhibit the growth and survival of NSCLC cells, which the Akt/mTOR/P70S6K pathway may be involved in. These results confer the pro-oncogenic role of CB2 in the progression of NSCLC, thus improving our understanding of CB2 in tumor progression.”

https://www.ncbi.nlm.nih.gov/pubmed/31176172

https://www.sciencedirect.com/science/article/pii/S0753332219321341?via%3Dihub

“Cannabinoid receptors, CB1 and CB2, as novel targets for inhibition of non-small cell lung cancer growth and metastasis. These results suggest that CB1 and CB2 could be used as novel therapeutic targets against NSCLC.”  https://www.ncbi.nlm.nih.gov/pubmed/21097714

The cannabinoid receptor 2 agonist, β-caryophyllene, improves working memory and reduces circulating levels of specific proinflammatory cytokines in aged male mice.

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Behavioural Brain Research“Age-related cognitive decline has been associated with proinflammatory cytokines, yet the precise relationship between cognitive decline and cytokine load remains to be elucidated. β-caryophyllene (BCP) is a cannabinoid receptor 2 (CB2) agonist with established anti-inflammatory effects that is known to improve memory and increase lifespan. It is of interest to explore the potential of BCP to reduce age-related cognitive decline and proinflammatory cytokine load. In this study, we assessed changes in circulating cytokines across the lifespan, memory performance in young and aged mice, and the effects of BCP on memory function and cytokine load. The plasma levels of 12 cytokines were assessed in male Swiss-Webster mice at 3, 12, and 18 months of age using multiplexed flow cytometry. Working memory was compared in 3 and 12 month-old mice using spontaneous alternations. A dose-response function (100-300 mg/kg, subchronic administration) for BCP-induced memory restoration was determined in 3 and 12 month-old mice. Finally, the effects on cytokine levels of the peak memory enhancing dose of BCP was assessed in 18 month-old mice. Circulating levels of several cytokines significantly increased with age. Multilinear regression analysis showed that IL-23 levels were most strongly associated with age. Aged mice showed deficits in working memory and higher levels of IL-23, both of which were reversed by BCP treatment. BCP appears to reverse age-associated impairments in memory and modulates cytokine production. IL-23 may play a significant role in the aging process, and future research should determine whether it has utility as a biomarker for novel anti-aging therapeutics.”

https://www.ncbi.nlm.nih.gov/pubmed/31173795

https://www.sciencedirect.com/science/article/pii/S0166432819304516?via%3Dihub

“β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.”   http://www.ncbi.nlm.nih.gov/pubmed/23138934

“Beta-caryophyllene is a dietary cannabinoid.”   https://www.ncbi.nlm.nih.gov/pubmed/18574142

Bipolar disorder and the endocannabinoid system.

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 Image result for acta neuropsychiatrica“Bipolar disorder (BD) is a debilitating, lifelong neuropsychiatric illness characterised by unsteady mood states which vacillate from (hypo)mania to depression. Despite the availability of pharmaceutical agents which can be effective in ameliorating the acute affective symptoms and prevent episodic relapse, BD is inadequately treated in a subset of patients.

The endocannabinoid system (ECS) is known to exert neuromodulatory effects on other neurotransmitter systems critical in governing emotions. Several studies ranging from clinical to molecular, as well as anecdotal evidence, have placed a spotlight on the potential role of the ECS in the pathophysiology of BD. In this perspective, we present advantages and disadvantages of cannabis use in the management of illness course of BD and provide mechanistic insights into how this system might contribute to the pathophysiology of BD.

RESULTS:

We highlight the putative role of selective cannabinoid receptor 2 (CB2) agonists in BD and briefly discuss findings which provide a rationale for targeting the ECS to assuage the symptoms of BD. Further, data encourage basic and clinical studies to determine how cannabis and cannabinoids (CBs) can affect mood and to investigate emerging CB-based options as probable treatment approaches.

CONCLUSION:

The probable role of the ECS has been almost neglected in BD; however, from data available which suggest a role of ECS in mood control, it is justified to support conducting comprehensive studies to determine whether ECS manipulation could positively affect BD. Based on the limited available data, we suggest that activation of CB2 may stabilise mood in this disorder.”

https://www.ncbi.nlm.nih.gov/pubmed/31159897

https://www.cambridge.org/core/journals/acta-neuropsychiatrica/article/bipolar-disorder-and-the-endocannabinoid-system/0C3191AF7BECA6D5A6EBED3C94CAA57B

A selective CB2 agonist protects against the inflammatory response and joint destruction in collagen-induced arthritis mice.

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Biomedicine & Pharmacotherapy

“Rheumatoid arthritis (RA) is a chronic, inflammatory, synovitis-dominated systemic disease with unknown etiology. RA is characterized by the involvement of multiple affected joints, symmetry, and invasive arthritis of the limbs, which can lead to joint deformity, cartilage destruction, and loss of function. Cannabinoid receptor 2 (CB2) has potent immunomodulatory and anti-inflammatory effects and is predominantly expressed in non-neuronal tissues. In the current study, the role of CB2 in the process of inflammatory bone erosion in RA was examined. The selective agonist or high-affinity ligand of CB2 (4-quinolone-3-carboxamides CB2 agonist, 4Q3C CB2agonist, 4Q3C) significantly reduced the severity of arthritis, decreased histopathological findings, and markedly reduced bone erosion in collagen-induced arthritis (CIA) mice. In addition, 4Q3C prevented an increase in the nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) ratio and inhibited the formation of osteoclasts in CIA mice. Furthermore, the expression of tumor necrosis factor-alpha, interleukin-1β, cyclooxygenase-2, and inducible nitric oxide synthase was lower in 4Q3C-treated CIA mice than in control CIA mice. Micro-computed tomography corroborated the finding that 4Q3C reduced joint destruction. These data clearly indicate that the CB2-selective agonist, 4Q3C, may have anti-inflammatory and anti-osteoclastogenesis effects in RA and may be considered to be a novel treatment for RA.”

https://www.ncbi.nlm.nih.gov/pubmed/31154267

https://www.sciencedirect.com/science/article/pii/S0753332219307528?via%3Dihub

CB2 Cannabinoid receptor agonist ameliorates novel object recognition but not spatial memory in transgenic APP/PS1 mice.

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Neuroscience Letters

“The cannabinoid receptor 2 (CB2R) has been considered as a potential therapeutic target to ameliorate the neuroinflammation and cognitive impairments of Alzheimer’s disease (AD). However, there has been little research on the diverse roles of CB2R in regulating different forms of cognitive abilities and underlying neuroinflammatory mechanisms. Thus, the focus of the present study was to investigate the effects of CB2R activation on cognitive abilities, activation and phenotype conversion of microglia, and dendrite complexity.

Results showed that CB2R activation normalized the cortex-dependent novel object recognition memory deficit in a novel object recognition test (P < 0.05) and CB2R activation was ineffective for hippocampus-dependent spatial cognitive dysfunction in the Morris water maze test (P > 0.05). Moreover, activation of CB2R did not affect the formation of plaque in either the cortex or hippocampus (P > 0.05). Interestingly, in the cortex but not in the hippocampus of APP/PS1 mice, there was decreased immunofluorescence intensity of Iba1, M1 to M2 microglial phenotype conversion, and restored dendritic complexity after a long treatment period of CB2R agonist (All P < 0.05).

Our results demonstrated that CB2R activation exerts a beneficial role in novel object recognition ability concomitant with region-specific regulation in microglia-mediated neuroinflammation and dendritic complexity in AD-model mice.”

https://www.ncbi.nlm.nih.gov/pubmed/31150731

https://www.sciencedirect.com/science/article/pii/S0304394019303581?via%3Dihub