Tag Archives: cannabinoid receptors

Cannabigerol Action at Cannabinoid CB1 and CB2 Receptors and at CB1–CB2 Heteroreceptor Complexes

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“Cannabigerol (CBG) is one of the major phytocannabinoids present in Cannabis sativa L. that is attracting pharmacological interest because it is non-psychotropic and is abundant in some industrial hemp varieties.

The aim of this work was to investigate in parallel the binding properties of CBG to cannabinoid CB1 (CB1R) and CB2 (CB2R) receptors and the effects of the compound on agonist activation of those receptors and of CB1–CB2 heteroreceptor complexes.

The results indicate that CBG is indeed effective as regulator of endocannabinoid signaling.

In conclusion, the results presented in this study reveal that the non-psychotropic phytocannabinoid, CBG, may exert beneficial actions with therapeutic potential via cannabinoid receptors.”

https://www.frontiersin.org/articles/10.3389/fphar.2018.00632/full

“International Multi-Centre Collaboration Reveals that Cannabigerol Acts Directly on Cannabinoid Receptors CB1 and CB2” https://www.prnewswire.com/news-releases/international-multi-centre-collaboration-reveals-that-cannabigerol-acts-directly-on-cannabinoid-receptors-cb1-and-cb2-300671024.html

Appraising the “entourage effect”: antitumor action of a pure cannabinoid versus a botanical drug preparation in preclinical models of breast cancer.

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“Breast cancer is the second leading cause of death among women. Although early diagnosis and development of new treatments have improved their prognosis, many patients present innate or acquired resistance to current therapies. New therapeutic approaches are therefore warranted for the management of this disease.

Extensive preclinical research has demonstrated that cannabinoids, the active ingredients of Cannabis sativa, trigger antitumor responses in different models of cancer. Most of these studies have been conducted with pure compounds, mainly Δ9-tetrahydrocannabinol (THC).

The cannabis plant, however, produces hundreds of other compounds with their own therapeutic potential and the capability to induce synergic responses when combined, the so-called “entourage effect”.

Here, we compared the antitumor efficacy of pure THC with that of a botanical drug preparation (BDP). The BDP was more potent than pure THC in producing antitumor responses in cell culture and animal models of ER+/PR+, HER2+ and triple-negative breast cancer. This increased potency was not due to the presence of the 5 most abundant terpenes in the preparation.

While pure THC acted by activating cannabinoid CB2 receptors and generating reactive oxygen species, the BDP modulated different targets and mechanisms of action. The combination of cannabinoids with estrogen receptor- or HER2-targeted therapies (tamoxifen and lapatinib, respectively) or with cisplatin, produced additive antiproliferative responses in cell cultures. Combinations of these treatments in vivo showed no interactions, either positive or negative.

Together, our results suggest that standardized cannabis drug preparations, rather than pure cannabinoids, could be considered as part of the therapeutic armamentarium to manage breast cancer.”

 https://www.ncbi.nlm.nih.gov/pubmed/29940172

Inhibition of endocannabinoid degradation rectifies motivational and dopaminergic deficits in the Q175 mouse model of Huntington’s disease.

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“Prominent motor deficits (e.g., chorea) that typify Huntington’s disease (HD) arise following a prolonged prodromal stage characterized by psychiatric disturbances. Apathy, a disorder of motivation characterized by diminished goal-directed behavior, is one of the earliest and most common psychiatric symptoms in HD, but the underlying neurobiology is unclear and treatment options are limited.

Alterations in the endocannabinoid (eCB) and dopamine systems represent prominent pathophysiological markers in HD that-similar to motivational deficits-present early and decline across disease progression. Whether changes in dopamine and eCB systems are associated with specific behavioral impairments in HD and whether these deficits are amenable to viable treatments is unknown.

Here, we show that dopaminergic encoding of effortful drive progressively declines with age in an HD mouse model, and is restored by elevating tissue levels of the eCB 2-arachidonoylglycerol (2-AG) through targeted inhibition of its enzymatic degradation.

This work supports aberrant dopaminergic encoding of reward as a neurobiological correlate of apathy in HD, and indicates that cannabinoid receptor-based therapies may benefit neuropsychiatric care for HD.”

https://www.ncbi.nlm.nih.gov/pubmed/29925886

https://www.nature.com/articles/s41386-018-0107-8

Cannabidiol did not induce teratogenicity or neurotoxicity in exposed zebrafish embryos.

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“Cannabidiol (CBD) is a non-psychotomimetic compound of the Cannabis sativa that has been used for the treatment of severe epilepsy as well as other diseases of nervous system. However, toxicity studies of CBD have great relevance to guarantee the patients safety.

In this context, morphological analyses of zebrafish can contribute to evaluate the teratogenic potential, as well as evaluation of acetylcholinesterase activity and motor activity of zebrafish are valuable tools to verify the neurotoxicity potential. In the present work, we use this methodology to test the toxicity of CBD to zebrafish embryos.

No malformation was observed in morphological analysis of embryos exposed to all tested concentrations of CBD.

Embryos exposed to CBD did not show differences in acetylcholinesterase activity, but embryos exposed to CBD 20-300 μg/L were 1.4 up to 1.7-fold more active when compared to the control. Despite that, at 48 hpf, motor activity returned to control values.

Our results suggest that the effects observed after CBD exposure are intimately related to CB1 receptor that is present in zebrafish since early stages of development. The present work showed early light effects induced by CBD exposure in concentrations that did not alter biochemical activity.”

 https://www.ncbi.nlm.nih.gov/pubmed/29902416
https://www.sciencedirect.com/science/article/pii/S0009279718302163

The Role of Cannabinoids in the Setting of Cirrhosis.

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“Although the mortality rates of cirrhosis are underestimated, its socioeconomic burden has demonstrated a significant global impact. Cirrhosis is defined by the disruption of normal liver architecture after years of chronic insult by different etiologies. Treatment modalities are recommended primarily in decompensated cirrhosis and specifically tailored to the different manifestations of hepatic decompensation. Antifibrogenic therapies are within an active area of investigation.

The endocannabinoid system has been shown to play a role in liver disease, and cirrhosis specifically, with intriguing possible therapeutic benefits. The endocannabinoid system comprises cannabinoid receptors 1 (CB1) and cannabinoid receptor 2 (CB2) and their ligands, endocannabinoids and exocannabinoids.

CB1 activation enhances fibrogenesis, whereas CB2 activation counteracts progression to fibrosis. Conversely, deletion of CB1 is associated with an improvement of hepatic fibrosis and steatosis, and deletion of CB2 results in increased collagen deposition, steatosis, and enhanced inflammation.

CB1 antagonism has also demonstrated vascular effects in patients with cirrhosis, causing an increase in arterial pressure and vascular resistance as well as a decrease in mesenteric blood flow and portal pressure, thereby preventing ascites. In mice with hepatic encephalopathy, CB1 blockade and activation of CB2 demonstrated improved neurologic score and cognitive function.

Endocannabinoids, themselves also have mechanistic roles in cirrhosis. Arachidonoyl ethanolamide (AEA) exhibits antifibrogenic properties by inhibition of HSC proliferation and induction of necrotic death. AEA induces mesenteric vasodilation and hypotension via CB1 induction. 2-arachidonoyl glycerol (2-AG) is a fibrogenic mediator independent of CB receptors, but in higher doses induces apoptosis of HSCs, which may actually show antifibrotic properties. 2-AG has also demonstrated growth-inhibitory and cytotoxic effects.

The exocannabinoid, THC, suppresses proliferation of hepatic myofibroblasts and stellate cells and induces apoptosis, which may reveal antifibrotic and hepatoprotective mechanisms. Thus, several components of the endocannabinoid system have therapeutic potential in cirrhosis.”

https://www.ncbi.nlm.nih.gov/pubmed/29890719

http://www.mdpi.com/2305-6320/5/2/52

Betacaryophyllene – A phytocannabinoid as potential therapeutic modality for human sepsis?

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“Sepsis is a clinical condition resulting from a dysregulated immune response to an infection that leads to organ dysfunction. Despite numerous efforts to optimize treatment, sepsis remains to be the main cause of death in most intensive care units.

The endogenous cannabinoid system (ECS) plays an important role in inflammation.

Cannabinoid receptor 2 (CB2R) activation is immunosuppressive, which might be beneficial during the hyper-inflammatory phase of sepsis.

Beta-caryophyllene (BCP) is a non-psychoactive natural cannabinoid (phytocannabinoid) found in Cannabis sativa and in essential oils of spices and food plants, that acts as a selective agonist of CB2R.

We propose BCP administration as novel treatment to reduce hyper-inflammation in human sepsis.”

 https://www.ncbi.nlm.nih.gov/pubmed/29317072
https://www.medical-hypotheses.com/article/S0306-9877(17)30861-7/fulltext

Ischemia/Reperfusion Model Impairs Endocannabinoid Signaling and Na+/K+ ATPase Expression and Activity in Kidney Proximal Tubule Cells.

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“LLC-PK1 cells, an immortalized epithelial cell line derived from pig renal proximal tubules, express all the major players of the endocannabinoid system (ECS) such as CB1, CB2 and TRPV1 receptor, as well as the main enzymes involved in the biosynthesis and degradation of the major endocannabinoids named 2-arachidonoylglycerol, 2-AG and anandamide, AEA.

Here we investigated whether the damages caused by ischemic insult either in vitro using LLC-PK1 cells exposed to antimycin A (an inductor of ATP-depletion) or in vivo using Wistar rats in a classic renal ischemia and reperfusion (IR) protocol, lead to changes in AEA and 2-AG levels, as well as altered expression of genes from the main enzymes involved in the regulation of the ECS.

Our data show that the mRNA levels of CB1 receptor gene were downregulated, while the transcript levels of monoacylglycerol lipase (MAGL), the main 2-AG degradative enzyme, are upregulated in LLC-PK1 cells after IR model. Accordingly, IR was accompanied by a significant reduction in the levels of 2-AG and AEA, as well as of the two endocannabinoid related molecules, oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) in LLC-PK1 cells. In kidney cortex homogenates, the AEA levels were selectively significantly decreased. In addition, we found that both the in vitro and in vivo model of IR caused a reduction in the expression and activity of the Na+/K+ATPase. These changes were reversed by the CB1/CB2 agonist WIN55,212, in a CB1-receptor dependent manner on LLC-PK1 IR model.

In conclusion, the ECS and Na+/K+ ATPase are down-regulated following IR model in LLC-PK1 cells and rat kidney. We suggest that CB1 agonists might represent a potential strategy to reverse the consequences of IR injury in kidney tissues.”

https://www.ncbi.nlm.nih.gov/pubmed/29890144

https://www.sciencedirect.com/science/article/pii/S0006295218302132

Activation of GPR55 increases neural stem cell proliferation and promotes early adult hippocampal neurogenesis

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“The cannabinoid system exerts functional regulation of neural stem cell (NSC) proliferation and adult neurogenesis, yet not all effects of cannabinoid-like compounds seen can be attributed to the cannabinoid 1 receptor (CB1 R) or cannabinoid 2 receptor (CB2 R).

The recently de-orphaned GPR55 has been shown to be activated by numerous cannabinoid ligands suggesting that GPR55 is a third cannabinoid receptor.

Here we examined the role of GPR55 activation in NSC proliferation and early adult neurogenesis.

CONCLUSIONS AND IMPLICATIONS:

Together, these findings suggest GPR55 activation as a novel target and strategy to regulate NSC proliferation and adult neurogenesis.”

https://www.ncbi.nlm.nih.gov/pubmed/29888782

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14387

“The orphan receptor GPR55 is a novel cannabinoid receptor”  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2095107/

A cannabinoid receptor 2 agonist reduces blood-brain barrier damage via induction of MKP-1 after intracerebral hemorrhage in rats.

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“The blood-brain barrier (BBB) disruption and the following development of brain edema, is the most life-threatening secondary injury after intracerebral hemorrhage (ICH).

This study is to investigate a potential role and mechanism of JWH133, a selected cannabinoid receptor type2 (CB2R) agonist, on protecting blood-brain barrier integrity after ICH.

CONCLUSIONS:

CB2R agonist alleviated neuroinflammation and protected blood-brain barrier permeability in a rat ICH model. Further molecular mechanisms revealed which is probably mediated by enhancing the expression of MKP-1, then inhibited MAPKs signal transduction.”

https://www.ncbi.nlm.nih.gov/pubmed/29886251

The relationship of endocannabinoidome lipid mediators with pain and psychological stress in women with fibromyalgia – a case control study.

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“Characterized by chronic widespread pain, generalized hyperalgesia, and psychological stress fibromyalgia (FM) is difficult to diagnose and lacks effective treatments.

The endocannabinoids – arachidonoylethanolamide (AEA), 2-arachidonoylglycerol (2-AG), and the related oleoylethanolamide (OEA), palmitoylethanolamide (PEA), and stearoylethanolamide (SEA) – are endogenous lipid mediators with analgesic and anti-inflammatory characteristics, in company with psychological modulating properties (e.g., stress and anxiety), and are included in a new emerging “ome”, the endocannabinoidome.

This case -control study compared the concentration differences of AEA, OEA, PEA, SEA, and 2-AG in 104 women with FM and 116 healthy controls (CON). All participants OEArated their pain, anxiety, depression, and current health status. The relationships between the lipid concentrations and the clinical assessments were investigated using powerful multivariate data analysis and traditional bivariate statistics. The concentrations of OEA, PEA, SEA, and 2-AG were significantly higher in FM than in CON; significance remained for OEA and SEA after controlling for BMI and age. 2-AG correlated positively with FM duration and BMI, and to some extent negatively with pain, anxiety, depression, and health status. In FM, AEA correlated positively with depression ratings.

The elevated circulating levels of endocannabinoidome lipids suggest that these lipids play a role in the complex pathophysiology of FM and might be signs of ongoing low-grade inflammation in FM. Although the investigated lipids are significantly altered in FM their biological roles are uncertain with respect to the clinical manifestations of FM. Thus, plasma lipids alone are not good biomarkers for FM.

PERSPECTIVE:

This study reports about elevated plasma levels of endocannabinoidome lipid mediators in FM. The lipids suitability to work as biomarkers for FM in the clinic were low, however their altered levels indicate that a metabolic asymmetry is ongoing in FM, which could serve as basis during explorative FM pain management.”

https://www.ncbi.nlm.nih.gov/pubmed/29885369

https://www.jpain.org/article/S1526-5900(18)30197-4/fulltext