Tag Archives: cannabinoid receptors

Role of cannabinoid receptor type 1 in rostral ventrolateral medulla in high-fat diet-induced hypertension in rats.

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“Stimulation of cannabinoid type 1 (CB1) receptor in the rostral ventrolateral medulla (RVLM) increases renal sympathetic activity (RSNA) and blood pressure (BP) in rats. Thus, we hypothesized that CB1 receptor in the RVLM may play a critical role in the development of obesity-induced hypertension.

METHODS:

To this end, we evaluated the levels of endocannabinoids and CB1 receptors in the RVLM in high-fat diet (HFD)-induced hypertensive rats. We then used pharmacological and molecular methods to examine the role of RVLM CB1 receptors in regulation of BP, heart rate (HR), and RSNA in obesity-induced hypertensive rats.

RESULTS:

We found that HFD-fed rats exhibited higher basal BP, HR, and RSNA than standard diet-fed rats, which were associated with increased levels of endocannabinoids and CB1 receptor expression in the RVLM. Furthermore, unilateral intra-RVLM microinjections of AM251 (0, 100, or 500 nM/0.5 μl/site) dose-dependently decreased BP, HR, and RSNA to a greater extent in HFD-fed rats than in standard diet-fed rats. Finally, siRNA-mediated knockdown of CB1 receptor expression in the RVLM robustly decreased BP, HR, and RSNA in HFD-fed rats.

CONCLUSION:

Taken together, our results suggested that enhanced CB1 receptor-mediated neurotransmissions in the RVLM may play a role in the development of obesity-induced hypertension.”

https://www.ncbi.nlm.nih.gov/pubmed/29493561

https://insights.ovid.com/crossref?an=00004872-201804000-00015

Hypoxia mimetic activity of VCE-004.8, a cannabidiol quinone derivative: implications for multiple sclerosis therapy.

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“Multiple sclerosis (MS) is characterized by a combination of inflammatory and neurodegenerative processes variously dominant in different stages of the disease. Thus, immunosuppression is the goal standard for the inflammatory stage, and novel remyelination therapies are pursued to restore lost function.

Cannabinoids such as 9Δ-THC and CBD are multi-target compounds already introduced in the clinical practice for multiple sclerosis (MS). Semisynthetic cannabinoids are designed to improve bioactivities and druggability of their natural precursors. VCE-004.8, an aminoquinone derivative of cannabidiol (CBD), is a dual PPARγ and CB2agonist with potent anti-inflammatory activity.

Activation of the hypoxia-inducible factor (HIF) can have a beneficial role in MS by modulating the immune response and favoring neuroprotection and axonal regeneration.

We investigated the effects of VCE-004.8 on the HIF pathway in different cell types.

CONCLUSIONS:

This study provides new significant insights about the potential role of VCE-004.8 for MS treatment by ameliorating neuroinflammation and demyelination.”

https://www.ncbi.nlm.nih.gov/pubmed/29495967

https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-018-1103-y

Toxicity, Cannabinoids.

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“Cannabinoids are a collective group of compounds that act on cannabinoid receptors. They include plant-derived phytocannabinoids, synthetic cannabinoids, and endogenously-derived endocannabinoids. The primary source of cannabinoid toxicity is from plant-derived cannabinoids and synthetic cannabinoids. These agents act as cannabinoid receptor agonists. More than 60 naturally occurring cannabinoids are found in the Sativa and Indica species of Cannabis, with delta-9 tetrahydrocannabinol (THC) being the main psychoactive compound. Other naturally occurring cannabinoids include cannabidiol and cannabinol. Marijuana is the most common colloquial name for crushed, dried leaves and flowers of the Cannabis plant. In recent years, there have been many reports of marijuana toxicity, primarily in the pediatric population, as medical and recreational marijuana has been legalized. The terms phytocannabinoids, marijuana and cannabis are used interchangeably. Synthetic cannabinoids were created for therapeutic and research purposes; however, despite legal efforts to limit their availability, synthetic cannabinoids have become an increasingly common drug of abuse, sold under various street names such as K2, Spice, and Black Mamba. Synthetic cannabinoids are associated with much more morbidity and mortality than the phytocannabinoids. Prescription preparations for medical usage include dronabinol, or pure THC, nabilone, a synthetic cannabinoid, and cannabidiol (CBD). Pharmaceutical use of cannabinoids is an ongoing field of research.”

https://www.ncbi.nlm.nih.gov/pubmed/29489164

https://www.ncbi.nlm.nih.gov/books/NBK482175/

Innovative Therapeutic Potential of Cannabinoid Receptors as Targets in Alzheimer’s disease and Less Well-Known Diseases.

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“The discovery of cannabinoid receptors at the beginning of the 1990s, CB1 being cloned in 1990 and CB2 cloned in 1993, and the availability of selective and potent cannabimimetics could only be justified by the existence of endogenous ligands that are capable of binding to them. Thus, the characterisation and cloning of the first cannabinoid receptor (CB1) led to the isolation and characterisation of the first endocannabinoid, arachidonoylethanolamide (AEA), two years later and the subsequent identification of a family of lipid transmitters known as the fatty acid ester 2-arachidonoylglycerol (2-AG). The endogenous cannabinoid system is a complex signalling system that comprises transmembrane endocannabinoid receptors, their endogenous ligands (the endocannabinoids), the specific uptake mechanisms and the enzymatic systems related to their biosynthesis and degradation. The endocannabinoid system has been implicated in a wide diversity of biological processes, in both the central and peripheral nervous systems, including memory, learning, neuronal development, stress and emotions, food intake, energy regulation, peripheral metabolism, and the regulation of hormonal balance through the endocrine system. In this context, this article will review the current knowledge of the therapeutic potential of cannabinoid receptor as a target in Alzheimer’s disease and other less well-known diseases that include, among others, multiple sclerosis, bone metabolism, and Fragile X syndrome. The therapeutic applications will be addressed through the study of cannabinoid agonists acting as single drugs and multi-target drugs highlighting the CB2 receptor agonist.”

https://www.ncbi.nlm.nih.gov/pubmed/29484980

http://www.eurekaselect.com/160083/article

Cannabidiol inhibits pathogenic T cells, decreases spinal microglial activation and ameliorates multiple sclerosis-like disease in C57BL/6 mice.

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British Journal of Pharmacology

“Cannabis extracts and several cannabinoids have been shown to exert broad anti-inflammatory activities in experimental models of inflammatory CNS degenerative diseases.

Clinical use of many cannabinoids is limited by their psychotropic effects. However, phytocannabinoids like cannabidiol (CBD), devoid of psychoactive activity, are, potentially, safe and effective alternatives for alleviating neuroinflammation and neurodegeneration.

Treatment with CBD during disease onset ameliorated the severity of the clinical signs of EAE.

CBD, a non-psychoactive cannabinoid, ameliorates clinical signs of EAE in mice, immunized against MOG. Suppression of microglial activity and T-cell proliferation by CBD appeared to contribute to these beneficial effects.”

https://www.ncbi.nlm.nih.gov/pubmed/21449980

“In summary, we have shown that CBD administered to MOG-immunized C57BL/6 mice, at the onset of EAE disease, reduced the severity of the clinical signs of EAE. CBD treatment was accompanied by diminished axonal loss and inflammation (infiltration of T cells and microglial activation). Moreover, CBD prevented proliferation of myelin-specific T cells in vitro. These observations suggest that CBD may have potential for alleviating MS-like pathology.” http://onlinelibrary.wiley.com/doi/10.1111/j.1476-5381.2011.01379.x/full

“Study Shows Cannabidiol (CBD) Improves MS-Like Symptoms”  http://www.prohealth.com/library/showarticle.cfm?libid=31211

Exogenous Cannabinoid Efficacy: Merely a Pharmacokinetic Interaction?

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Clinical Pharmacokinetics

“Endocannabinoid pharmacology is now relatively well understood with a number of endocannabinoids and endogenous cannabinoid neurotransmitters identified and the pharmacokinetics relatively well ascertained.

Further, the cannabinoid receptors are now molecularly and pharmacologically characterised and the cell processes involved in endocannabinoid transcription, synthesis, post-translational modification and protein expression are reported.

Endogenous cannabinoids have been shown to have key roles in immune and pain pathways and neuro-behavioural signalling including appetite regulation. Significant recent interest has thus been shown in understanding these pathways to guide the development of agents that inhibit the natural catabolism of endogenous cannabinoids to modify pain and appetite, and to synthesise antagonists for the treatment of disease such as obesity.

This research is concurrent with the renewed clinical interest in exogenous cannabinoids and their use in disease. However, the complex pharmacology and physiological effects of exogenous cannabinoids, either as individual components or in combination, as extracts or via administration of the whole plant in humans, are less well known.

Yet as with all other therapeutics, including those derived from plants, knowledge of the pharmacokinetics and dynamics of the complete plant, the individual chemical molecules and their synthetic versions, including formulations and excipients is a standard part of drug development.

This article covers the key pharmacological knowledge required to guide further exploration of the toxicity and efficacy of different cannabinoids and their formulations in blinded placebo-controlled studies.”

https://www.ncbi.nlm.nih.gov/pubmed/28921125

https://link.springer.com/article/10.1007%2Fs40262-017-0599-0

The Role of Cannabinoid Receptor 1 in the Immunopathology of Respiratory Syncytial Virus.

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Mary Ann Liebert, Inc. publishers

“Endocannabinoid system plays an important role in pathophysiologic processes such as immune functions and impacts on disease severity.

Our previous study showed that cannabinoid receptor 2 (CB2) affects clinical course of respiratory syncytial virus (RSV) infection. In this study, we investigated the role of cannabinoid receptor 1 (CB1) in RSV immunopathology and its therapeutic potential in mice model.

This study and our previous finding indicated that endocannabinoid signaling regulates the inflammatory response to RSV infection, and is a potential therapeutic candidate for alleviation of RSV-associated immunopathology.”

https://www.ncbi.nlm.nih.gov/pubmed/29461930

http://online.liebertpub.com/doi/10.1089/vim.2017.0098

Sex differences in antinociceptive response to Δ-9-tetrahydrocannabinol and CP 55,940 in the mouse formalin test.

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“Cannabinoids have shown promise for the treatment of intractable pain states and may represent an alternative pharmacotherapy for pain management.

A growing body of clinical evidence suggests a role for sex in pain perception and in cannabinoid response.

We examined cannabinoid sensitivity and tolerance in male and female mice expressing a desensitization-resistant form (S426A/S430A) of the cannabinoid type 1 receptor (CB1R).

Mice were assessed for acute and inflammatory nociceptive behaviors in the formalin test following pretreatment with either vehicle or mixed CB1R/CB2R agonists, Δ-9-tetrahydrocannabinol ([INCREMENT]-THC) (1-6 mg/kg) or CP 55,940 (0.06-0.2 mg/kg). Tolerance to the effects of 6 mg/kg [INCREMENT]-THC or 0.1 mg/kg CP 55,940 was examined by the formalin test following chronic daily dosing.

Female mice showed decreased sensitivity to the effects of [INCREMENT]-THC and CP 55,940 compared with male mice. The S426A/S430A mutation increased the attenuation of nociceptive behaviors for both agonists in both sexes. Female mice displayed delayed tolerance to [INCREMENT]-THC compared with male mice, whereas the S426A/S430A mutation conferred a delay in tolerance to [INCREMENT]-THC in both sexes. Male S426A/S430A mutant mice also display resistance to tolerance to CP 55,940 compared with wild-type controls.

This study demonstrates sex and genotype differences in response for two different cannabinoid agonists. The results underscore the importance of including both male and female mice in preclinical studies of pain and cannabinoid pharmacology.”

https://www.ncbi.nlm.nih.gov/pubmed/29461336

https://insights.ovid.com/crossref?an=00001756-900000000-98413

Limited Access to a High Fat Diet Alters Endocannabinoid Tone in Female Rats.

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“Emerging evidence suggest an impaired endocannabinoid activity in the pathophysiology of binge eating disorder (BED). Herein, we investigated whether endocannabinoid tone could be modified as a consequence of dietary-induced binge eating in female rats.

For this purpose, brain levels of the endocannabinoids anandamide (AEA) and 2-arachidonoyl glycerol (2-AG), as well as two endocannabinoid-like lipids, oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), were assessed in different brain areas involved in the hedonic feeding (i.e., prefrontal cortex, nucleus accumbens, amygdala, hippocampus, and hypothalamus).

The brain density of cannabinoid type-1 receptors (CB1) was also evaluated. Furthermore, we determined plasma levels of leptin, ghrelin, and corticosterone hormones, which are well-known to control the levels of endocannabioids and/or CB1 receptors in the brain.

To induce binge eating behavior, rats were subject to an intermittent and limited access to a high fat diet (HFD) (margarine). Three experimental groups were used, all with ad libitum access to chow: control (CTRL), with no access to margarine; low restriction (LR), with 2 h margarine access 7 days/week; high restriction (HR), with 2 h margarine access 3 days/week. Bingeing was established when margarine intake in the HR group exceeded that of the LR group.

Our results show that, compared to CTRL, AEA significantly decreased in the caudate putamen, amygdala, and hippocampus of HR group. In contrast, 2-AG significantly increased in the hippocampus while OEA decreased in the hypothalamus. Similar to the HR group, AEA and OEA decreased respectively in the amygdala and hypothalamus and 2-AG increased in the hippocampus of LR group. Moreover, LR group also had AEA decreased in the prefrontal cortex and increased in the nucleus accumbens. In both groups we found the same reduction of CB1 receptor density in the prefrontal cortex compared to CTRL. Also, LR and HR groups showed alterations in both ghrelin and corticosterone levels, while leptin remained unaltered.

In conclusion, our findings show a modified endocannabinoid tone due to margarine exposure, in several brain areas that are known to influence the hedonic aspect of food. Even if not uniquely specific to binge eating, margarine-induced changes in endocannabinoid tone could contributes to the development and maintenance of this behavior.”

https://www.ncbi.nlm.nih.gov/pubmed/29456490

https://www.frontiersin.org/articles/10.3389/fnins.2018.00040/full

Cannabinoids prevent depressive-like symptoms and alterations in BDNF expression in a rat model of PTSD.

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“Posttraumatic stress disorder (PTSD) is a debilitating condition highly comorbid with depression. The endocannabinoid (eCB) system and brain-derived neurotrophic factor (BDNF) are suggestively involved in both disorders.

We examined whether cannabinoids can prevent the long-term depressive-like symptoms induced by exposure to the shock and situational reminders (SRs) model of PTSD. The CB1/2 receptor agonist WIN55,212-2 (0.5 mg/kg; i.p.), the fatty acid hydrolase (FAAH) inhibitor URB597 (0.3 mg/kg, i.p.) or vehicle were administered 2 h after severe shock.

Cannabinoids prevented the shock/SRs-induced alterations in social recognition memory, locomotion, passive coping, anxiety-like behavior, anhedonia, fear retrieval, fear extinction and startle response as well as the decrease in BDNF levels in the hippocampus and prefrontal cortex (PFC). Furthermore, significant correlations were found between depressive-like behaviors and BDNF levels in the brain.

The findings suggest that cannabinoids may prevent both depressive- and PTSD-like symptoms following exposure to severe stress and that alterations in BDNF levels in the brains’ fear circuit are involved in these effects.”

https://www.ncbi.nlm.nih.gov/pubmed/29458190

https://www.sciencedirect.com/science/article/pii/S027858461731000X