Tag Archives: CB(1) and CB(2) receptors

Alterations in Brain Cannabinoid Receptor Levels Are Associated with HIV-Associated Neurocognitive Disorders in the ART Era: Implications for Therapeutic Strategies Targeting the Endocannabinoid System

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viruses-logo“HIV-associated neurocognitive disorders (HAND) persist despite the advent of antiretroviral therapy (ART), suggesting underlying systemic and central nervous system (CNS) inflammatory mechanisms.

The endogenous cannabinoid receptors 1 and 2 (CB1 and CB2) modulate inflammatory gene expression and play an important role in maintaining neuronal homeostasis. Cannabis use is disproportionately high among people with HIV (PWH) and may provide a neuroprotective effect for those on ART due to its anti-inflammatory properties. However, expression profiles of CB1 and CB2 in the brains of PWH on ART with HAND have not been reported.

In this study, biochemical and immunohistochemical analyses were performed to determine CB1 and CB2 expression in the brain specimens of HAND donors.

Immunoblot revealed that CB1 and CB2 were differentially expressed in the frontal cortices of HAND brains compared to neurocognitively unimpaired (NUI) brains of PWH. CB1 expression levels negatively correlated with memory and information processing speed. CB1 was primarily localized to neuronal soma in HAND brains versus a more punctate distribution of neuronal processes in NUI brains. CB1 expression was increased in cells with glial morphology and showed increased colocalization with an astroglial marker.

These results suggest that targeting the endocannabinoid system may be a potential therapeutic strategy for HAND.”

https://pubmed.ncbi.nlm.nih.gov/34578323/

https://www.mdpi.com/1999-4915/13/9/1742

The potential of cannabinoids and inhibitors of endocannabinoid degradation in respiratory diseases

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European Journal of Pharmacology“The global incidence of respiratory diseases and complications is increasing. Therefore, new methods of treatment, as well as prevention, need to be investigated.

A group of compounds that should be considered for use in respiratory diseases is cannabinoids. There are three groups of cannabinoids – plant-derived phytocannabinoids, synthetic cannabinoids, and endogenous endocannabinoids including the enzymes responsible for their synthesis and degradation.

All cannabinoids exert their biological effects through either type 1 cannabinoid receptors (CB1) and/or type 2 cannabinoid receptors (CB2). In numerous studies (in vitro and in vivo), cannabinoids and inhibitors of endocannabinoid degradation have shown beneficial anti-inflammatory, antioxidant, anti-cancer, and anti-fibrotic properties.

Although in the respiratory system, most of the studies have focused on the positive properties of cannabinoids and inhibitors of endocannabinoid degradation. There are few research reports discussing the negative impact of these compounds. This review summarizes the properties and mechanisms of action of cannabinoids and inhibitors of endocannabinoid degradation in various models of respiratory diseases.

A short description of the effects selected cannabinoids have on the human respiratory system and their possible use in the fight against COVID-19 is also presented. Additionally, a brief summary is provided of cannabinoid receptors properties and their expression in the respiratory system and cells of the immune system.”

https://pubmed.ncbi.nlm.nih.gov/34648805/

“Phytocannabinoids are terpenophenolic compounds produced by specialized parts of the Cannabis sativa plant and are found in high concentrations in marijuana and hashish. In most of models, these compounds have shown positive biological properties. Anti-inflammatory, anti-oxidant, anti-cancer and anti-fibrotic actions are especially emphasized.”

https://www.sciencedirect.com/science/article/pii/S0014299921007160?via%3Dihub

Cannabinoids and Cancer

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cancers-logo“Cannabinoids, active components of the plant Cannabis sativa, had been used for centuries in ancient medicine as therapeutic remedies for a variety of conditions, before becoming stigmatized due to their psychoactive effects.

In the second half of the 19th century, phyto-cannabinoids have been re-evaluated after the discovery of the chemical structure and isolation of different substances, and the subsequent development of cannabinoid-based drugs that have been FDA approved mainly to treat chemotherapy-induced nausea, insomnia and appetite, epilepsy, spasticity, and pain management.

Then, the elucidation of the endocannabinoid system, from the initial type 1 and type 2 (CB1 and CB2) cannabinoid receptors and their endogenous ligands (especially N-arachidonoylethanolamine, or anandamide, and 2-arachidonoylglycerol) to the emerging complexity of a wider system made up of additional putative receptors, ligands and enzymes, altogether termed endocannabinoidome, has further boosted research into the therapeutic potential of phyto-, endo- and even syntho-(synthetic) cannabinoids, cancer treatment included.”

https://pubmed.ncbi.nlm.nih.gov/34503268/

https://www.mdpi.com/2072-6694/13/17/4458/htm

Localisation of Cannabinoid and Cannabinoid-Related Receptors in the Horse Ileum

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Journal of Equine Veterinary Science“Colic is a common digestive disorder in horses and one of the most urgent problems in equine medicine. A growing body of literature has indicated that the activation of cannabinoid receptors could exert beneficial effects on gastrointestinal inflammation and visceral hypersensitivity.

The localisation of cannabinoid and cannabinoid-related receptors in the intestine of the horse has not yet been investigated. The purpose of this study was to immunohistochemically localise the cellular distribution of canonical and putative cannabinoid receptors in the ileum of healthy horses.

Distal ileum specimens were collected from six horses at the slaughterhouse. The tissues were fixed and processed to obtain cryosections which were used to investigate the immunoreactivity of canonical cannabinoid receptors 1 (CB1R) and 2 (CB2R), and three putative cannabinoid-related receptors: nuclear peroxisome proliferator-activated receptor-alpha (PPARα), transient receptor potential ankyrin 1 and serotonin 5-HT1a receptor (5-HT1aR).

Cannabinoid and cannabinoid-related receptors showed a wide distribution in the ileum of the horse.

The epithelial cells showed immunoreactivity for CB1R, CB2R and 5-HT1aR. Lamina propria inflammatory cells showed immunoreactivity for CB2R and 5-HT1aR. The enteric neurons showed immunoreactivity for CB1R, transient receptor potential ankyrin 1 and PPARα. The enteric glial cells showed immunoreactivity for CB1R and PPARα. The smooth muscle cells of the tunica muscularis and the blood vessels showed immunoreactivity for PPARα.

The present study represents a histological basis which could support additional studies regarding the distribution of cannabinoid receptors during gastrointestinal inflammatory diseases as well as studies assessing the effects of non-psychotic cannabis-derived molecules in horses for the management of intestinal diseases.”

https://pubmed.ncbi.nlm.nih.gov/34416995/

“Horses are often affected by gastrointestinal pathologies. Researchers are searching for new therapies for equine gastrointestinal diseases. New products with cannabinoid receptor agonists have been produced for horses. Cannabinoid receptors showed a wide distribution in the ileum of the horse. Activation of cannabinoids receptors could attenuate intestinal inflammation.”

https://www.sciencedirect.com/science/article/abs/pii/S073708062100318X?via%3Dihub

 

Cannabis sativa L. as a Natural Drug Meeting the Criteria of a Multitarget Approach to Treatment

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ijms-logo“Cannabis sativa L. turned out to be a valuable source of chemical compounds of various structures, showing pharmacological activity. The most important groups of compounds include phytocannabinoids and terpenes.

The pharmacological activity of Cannabis (in epilepsy, sclerosis multiplex (SM), vomiting and nausea, pain, appetite loss, inflammatory bowel diseases (IBDs), Parkinson’s disease, Tourette’s syndrome, schizophrenia, glaucoma, and coronavirus disease 2019 (COVID-19)), which has been proven so far, results from the affinity of these compounds predominantly for the receptors of the endocannabinoid system (the cannabinoid receptor type 1 (CB1), type two (CB2), and the G protein-coupled receptor 55 (GPR55)) but, also, for peroxisome proliferator-activated receptor (PPAR), glycine receptors, serotonin receptors (5-HT), transient receptor potential channels (TRP), and GPR, opioid receptors.

The synergism of action of phytochemicals present in Cannabis sp. raw material is also expressed in their increased bioavailability and penetration through the blood-brain barrier. This review provides an overview of phytochemistry and pharmacology of compounds present in Cannabis extracts in the context of the current knowledge about their synergistic actions and the implications of clinical use in the treatment of selected diseases.”

https://pubmed.ncbi.nlm.nih.gov/33466734/

https://www.mdpi.com/1422-0067/22/2/778

Therapeutic Attributes of Endocannabinoid System against Neuro-Inflammatory Autoimmune Disorders

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molecules-logo“In humans, various sites like cannabinoid receptors (CBR) having a binding affinity with cannabinoids are distributed on the surface of different cell types, where endocannabinoids (ECs) and derivatives of fatty acid can bind. The binding of these substance(s) triggers the activation of specific receptors required for various physiological functions, including pain sensation, memory, and appetite.

The ECs and CBR perform multiple functions via the cannabinoid receptor 1 (CB1); cannabinoid receptor 2 (CB2), having a key effect in restraining neurotransmitters and the arrangement of cytokines. The role of cannabinoids in the immune system is illustrated because of their immunosuppressive characteristics. These characteristics include inhibition of leucocyte proliferation, T cells apoptosis, and induction of macrophages along with reduced pro-inflammatory cytokines secretion.

The review seeks to discuss the functional relationship between the endocannabinoid system (ECS) and anti-tumor characteristics of cannabinoids in various cancers.

The therapeutic potential of cannabinoids for cancer-both in vivo and in vitro clinical trials-has also been highlighted and reported to be effective in mice models in arthritis for the inflammation reduction, neuropathic pain, positive effect in multiple sclerosis and type-1 diabetes mellitus, and found beneficial for treating in various cancers.

In human models, such studies are limited; thereby, further research is indispensable in this field to get a conclusive outcome. Therefore, in autoimmune disorders, therapeutic cannabinoids can serve as promising immunosuppressive and anti-fibrotic agents.”

https://pubmed.ncbi.nlm.nih.gov/34205169/

https://www.mdpi.com/1420-3049/26/11/3389

Cancer Initiation, Progression and Resistance: Are Phytocannabinoids from Cannabis sativa L. Promising Compounds?

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molecules-logo“Cannabis sativa L. is a source of over 150 active compounds known as phytocannabinoids that are receiving renewed interest due to their diverse pharmacologic activities. Indeed, phytocannabinoids mimic the endogenous bioactive endocannabinoids effects through activation of CB1 and CB2 receptors widely described in the central nervous system and peripheral tissues.

All phytocannabinoids have been studied for their protective actions towards different biological mechanisms, including inflammation, immune response, oxidative stress that, altogether, result in an inhibitory activity against the carcinogenesis.

The role of the endocannabinoid system is not yet completely clear in cancer, but several studies indicate that cannabinoid receptors and endogenous ligands are overexpressed in different tumor tissues.

Recently, in vitro and in vivo evidence support the effectiveness of phytocannabinoids against various cancer types, in terms of proliferation, metastasis, and angiogenesis, actions partially due to their ability to regulate signaling pathways critical for cell growth and survival.

The aim of this review was to report the current knowledge about the action of phytocannabinoids from Cannabis sativa L. against cancer initiation and progression with a specific regard to brain, breast, colorectal, and lung cancer as well as their possible use in the therapies. We will also report the known molecular mechanisms responsible for such positive effects.

Finally, we will describe the actual therapeutic options for Cannabis sativa L. and the ongoing clinical trials.”

https://pubmed.ncbi.nlm.nih.gov/34063214/

https://www.mdpi.com/1420-3049/26/9/2668

The Interplay between the Immune and the Endocannabinoid Systems in Cancer

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cells-logo“The therapeutic potential of Cannabis sativa has been recognized since ancient times. Phytocannabinoids, endocannabinoids and synthetic cannabinoids activate two major G protein-coupled receptors, subtype 1 and 2 (CB1 and CB2). Cannabinoids (CBs) modulate several aspects of cancer cells, such as apoptosis, autophagy, proliferation, migration, epithelial-to-mesenchymal transition and stemness. Moreover, agonists of CB1 and CB2 receptors inhibit angiogenesis and lymphangiogenesis in vitro and in vivo. Low-grade inflammation is a hallmark of cancer in the tumor microenvironment (TME), which contains a plethora of innate and adaptive immune cells. These cells play a central role in tumor initiation and growth and the formation of metastasis. CB2 and, to a lesser extent, CB1 receptors are expressed on a variety of immune cells present in TME (e.g., T cells, macrophages, mast cells, neutrophils, NK cells, dendritic cells, monocytes, eosinophils). The activation of CB receptors modulates a variety of biological effects on cells of the adaptive and innate immune system. The expression of CB2 and CB1 on different subsets of immune cells in TME and hence in tumor development is incompletely characterized. The recent characterization of the human cannabinoid receptor CB2-Gi signaling complex will likely aid to design potent and specific CB2/CB1 ligands with therapeutic potential in cancer.”

https://pubmed.ncbi.nlm.nih.gov/34064197/

https://www.mdpi.com/2073-4409/10/6/1282

The Molecular targets of Cannabinoids in the treatment of Cancer and Inflammation

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“In this review we discuss the emerging evidence for the effectiveness of cannabinoids in the treatment of cancer and inflammation. The remarkable effects complete the traditional evidence for their successful application in the treatment of pain and cancer-related side effects.

Results: Cannabinoids are described in three different forms, comprising endo- phyto- and synthetic compounds that exert biological effects. The molecular and cellular pathways of endogenous cannabinoids in the maintenance of homeostasis are well documented. In addition to classical cannabinoid receptors type 1 and 2, Vanilloid receptors and G protein-coupled receptor 55 were identified as common receptors. Subsequently, the effectiveness of phyto- and synthetic cannabinoids mediated by cannabinoid receptors has been demonstrated in the treatment of inflammatory diseases including neurodegenerative diseases as well as gastrointestinal and respiratory inflammations.

Another accepted property of cannabinoids is their anti-cancer effects. Cannabinoids were found to be effective in the treatment of lung, colorectal, prostate, breast, pancreas and hepatic cancers. The anticancer effects of cannabinoids were characterized by their anti-proliferative property, inhibition of cancer cells migration, suppression of vascularization and induction of apoptosis.

Conclusion: The current review provides and overview the role of endocannabinoid system in the mediation of physiological functions, the type and expression of cannabinoids receptors under physiological and pathological conditions. In additions, the molecular pathways involved in the effects of cannabinoids and the effectiveness of cannabinoids in the treatment of inflammations and cancers are highlighted.”

https://pubmed.ncbi.nlm.nih.gov/33902407/

https://www.eurekaselect.com/193013/article

THC Reduces Ki67-Immunoreactive Cells Derived from Human Primary Glioblastoma in a GPR55-Dependent Manner

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cancers-logo

“Glioblastoma (GBM) is the most frequent malignant tumor of the central nervous system in humans with a median survival time of less than 15 months.

∆9-Tetrahydrocannabinol (THC) and cannabidiol (CBD) are the best-characterized components of Cannabis sativa plants with modulating effects on cannabinoid receptors 1 and 2 (CB1 and CB2) and on orphan receptors such as GPR18 or GPR55. Previous studies have demonstrated anti-tumorigenic effects of THC and CBD in several tumor entities including GBM, mostly mediated via CB1 or CB2.

In this study, we investigated the non-CB1/CB2 effects of THC on the cell cycle of GBM cells isolated from human tumor samples.

Cell cycle entry was measured after 24 h upon exposure by immunocytochemical analysis of Ki67 as proliferation marker. The Ki67-reducing effect of THC was abolished in the presence of CBD, whereas CBD alone did not cause any changes. To identify the responsible receptor for THC effects, we first characterized the cells regarding their expression of different cannabinoid receptors: CB1, CB2, GPR18, and GPR55. Secondly, the receptors were pharmacologically blocked by application of their selective antagonists AM281, AM630, O-1918, and CID16020046 (CID), respectively. All examined cells expressed the receptors, but only in presence of the GPR55 antagonist CID was the THC effect diminished. Stimulation with the GPR55 agonist lysophosphatidylinositol (LPI) revealed similar effects as obtained for THC. The LPI effects were also inhibited by CBD and CID, confirming a participation of GPR55 and suggesting its involvement in modifying the cell cycle of patient-derived GBM cells.”

https://pubmed.ncbi.nlm.nih.gov/33802282/

“Glioblastoma (GBM) is the most frequent primary brain tumor entity with poor prognosis and resistance to current standard therapies. Cannabinoids, such as tetrahydrocannabinol (THC) and cannabidiol (CBD) are discussed as promising compounds for individualized treatment, as they exert anti-tumor effects by binding to cannabinoid-specific receptors. However, their pharmacology is highly diverse and complex. The present study was designed to verify (1) whether cannabinoids show even any effect in GBM cells derived from primary human tumor samples and (2) to identify the receptor responsible for those effects. Our findings revealed that THC reduces the number of Ki67 immunoreactive nuclei, a cell cycle marker through the orphan cannabinoid receptor GPR55. The data suggest a therapeutic potential of cannabinoids in those GBM with functional and responsive GPR55.”

https://www.mdpi.com/2072-6694/13/5/1064