Ligands for cannabinoid receptors, promising anticancer agents.

Posted on January 15, 2016 by David

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“Cannabinoid compounds are unique to cannabis and provide some interesting biological properties.

These compounds along with endocannabinoids, a group of neuromodulator compounds in the body especially in brain, express their effects by activation of G-protein-coupled cannabinoid receptors, CB1 and CB2.

There are several physiological properties attributed to the endocannabinoids including pain relief, enhancement of appetite, blood pressure lowering during shock, embryonic development, and blocking of working memory.

On the other hand, activation of endocannabinoid system may be suppresses evolution and progression of several types of cancer.

According to the results of recent studies, CB receptors are over-expressed in cancer cell lines and application of multiple cannabinoid or cannabis-derived compounds reduce tumor size through decrease of cell proliferation or induction of cell cycle arrest and apoptosis along with desirable effect on decrease of tumor-evoked pain.

Therefore, modulation of endocannabinoid system by inhibition of fatty acid amide hydrolase (FAAH), the enzyme, which metabolized endocannabinoids, or application of multiple cannabinoid or cannabis-derived compounds, may be appropriate for the treatment of several cancer subtypes. This review focuses on how cannabinoid affect different types of cancers.”

http://www.ncbi.nlm.nih.gov/pubmed/26764235

http://www.thctotalhealthcare.com/category/cancer/

GPR55 – a putative “type 3” cannabinoid receptor in inflammation.

Posted on December 17, 2015 by David

“G protein-coupled receptor 55 (GPR55) shares numerous cannabinoid ligands with CB1 and CB2 receptors despite low homology with those classical cannabinoid receptors. The pharmacology of GPR55 is not yet fully elucidated; however, GPR55 utilizes a different signaling system and downstream cascade associated with the receptor.

Therefore, GPR55 has emerged as a putative “type 3″ cannabinoid receptor, establishing a novel class of cannabinoid receptor.

Furthermore, the recent evidence of GPR55-CB1 and GPR55-CB2 heteromerization along with its broad distribution from central nervous system to peripheries suggests the importance of GPR55 in various cellular processes and pathologies and as a potential therapeutic target in inflammation.”

http://www.ncbi.nlm.nih.gov/pubmed/26669245

Small Molecules from Nature Targeting G-Protein Coupled Cannabinoid Receptors: Potential Leads for Drug Discovery and Development.

Posted on December 15, 2015 by David

“The cannabinoid molecules are derived from Cannabis sativa plant which acts on the cannabinoid receptors types 1 and 2 (CB1 and CB2) which have been explored as potential therapeutic targets for drug discovery and development.

Currently, there are numerous cannabinoid based synthetic drugs used in clinical practice like the popular ones such as nabilone, dronabinol, and Δ9-tetrahydrocannabinol mediates its action through CB1/CB2receptors.

In recent years, many phytocannabinoids have been isolated from plants other than Cannabis. Several studies have shown that these phytocannabinoids show affinity, potency, selectivity, and efficacy towards cannabinoid receptors and inhibit endocannabinoid metabolizing enzymes, thus reducing hyperactivity of endocannabinoid systems.

Also, these naturally derived molecules possess the least adverse effects opposed to the synthetically derived cannabinoids. Therefore, the plant based cannabinoid molecules proved to be promising and emerging therapeutic alternative.

The present review provides an overview of therapeutic potential of ligands and plants modulating cannabinoid receptors that may be of interest to pharmaceutical industry in search of new and safer drug discovery and development for future therapeutics.”

http://www.ncbi.nlm.nih.gov/pubmed/26664449

Computational Prediction and Biochemical Analyses of New Inverse Agonists for the CB1 Receptor.

Posted on December 4, 2015 by David

“Human cannabinoid type 1 (CB1) G-protein coupled receptor is a potential therapeutic target for obesity.

The previously predicted and experimentally validated ensemble of ligand-free conformations of CB1 are used here to predict the binding sites for known CB1-selective inverse agonists including rimonabant and its seven known derivatives.

This binding pocket, which differs significantly from previously published models, is used to identify 16 novel compounds expected to be CB1 inverse agonists by exploiting potential new interactions.

We show experimentally that two of these compounds exhibit inverse agonist properties including inhibition of basal and agonist-induced G-protein coupling activity, as well as an enhanced level of CB1 cell surface localization.

This demonstrates the utility of using the predicted binding sites for an ensemble of CB1 receptor structures for designing new CB1 inverse agonists.”

http://www.ncbi.nlm.nih.gov/pubmed/26633590

The Cannabinoid Receptor CB1 Interacts with the WAVE1 Complex and Plays a Role in Actin Dynamics and Structural Plasticity in Neurons.

Posted on October 27, 2015 by David

“The molecular composition of the cannabinoid type 1 (CB1) receptor complex beyond the classical G-protein signaling components is not known.

Using proteomics on mouse cortex in vivo, we pulled down proteins interacting with CB1 in neurons and show that the CB1 receptor assembles with multiple members of the WAVE1 complex and the RhoGTPase Rac1 and modulates their activity…

This study reports novel signaling mechanisms for cannabinoidergic modulation of the nervous system and demonstrates a previously unreported role for the WAVE1 complex in therapeutic applications of cannabinoids.”

http://www.ncbi.nlm.nih.gov/pubmed/26496209

GPR55 promotes migration and adhesion of colon cancer cells indicating a role in metastasis.

Posted on October 7, 2015 by David

“Tumor cell migration and adhesion constitute essential features of metastasis. G protein-coupled receptor 55 (GPR55), a lysophospholipid receptor, has been shown to play an important role in carcinogenesis. Here, we investigated the involvement of GPR55 in migration and metastasis of colon cancer cells.

GPR55 antagonist CID16020046, cannabidiol, a putative GPR55 antagonist, and GPR55 siRNA were used to block GPR55 activity in HCT116 colon cancer cells.

In a mouse model of metastasis, the arrest of HCT116 cancer cells in the liver was reduced after treatment with CID16020046 or cannabidiol.

CONCLUSIONS AND IMPLICATIONS:

GPR55 is involved in the migratory behavior of colon carcinoma cells and may serve as a pharmacological target for the prevention of metastasis.”

http://www.ncbi.nlm.nih.gov/pubmed/26436760

“Pharmacological Characterization of GPR55, A Putative Cannabinoid Receptor” http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2874616/

Endocannabinoids and the Immune System in Health and Disease.

Posted on September 27, 2015 by David

“Endocannabinoids are bioactive lipids that have the potential to signal through cannabinoid receptors to modulate the functional activities of a variety of immune cells.

Their activation of these seven-transmembranal, G protein-coupled receptors sets in motion a series of signal transductional events that converge at the transcriptional level to regulate cell migration and the production of cytokines and chemokines.

There is a large body of data that supports a functional relevance for 2-arachidonoylglycerol (2-AG) as acting through the cannabinoid receptor type 2 (CB2R) to inhibit migratory activities for a diverse array of immune cell types.

However, unequivocal data that supports a functional linkage of anandamide (AEA) to a cannabinoid receptor in immune modulation remains to be obtained.

Endocannabinoids, as typical bioactive lipids, have a short half-life and appear to act in an autocrine and paracrine fashion.

Their immediate effective action on immune function may be at localized sites in the periphery and within the central nervous system.

It is speculated that endocannabinoids play an important role in maintaining the overall “fine-tuning” of the immune homeostatic balance within the host.”

http://www.ncbi.nlm.nih.gov/pubmed/26408161

Endocannabinoids and Their Pharmacological Actions.

Posted on September 27, 2015 by David

“The endocannabinoid system consists of G protein-coupled cannabinoid CB1 and CB2 receptors, of endogenous compounds known as endocannabinoids that can target these receptors, of enzymes that catalyse endocannabinoid biosynthesis and metabolism, and of processes responsible for the cellular uptake of some endocannabinoids.

This review presents in vitro evidence that most or all of the following 13 compounds are probably orthosteric endocannabinoids since they have all been detected in mammalian tissues in one or more investigation, and all been found to bind to cannabinoid receptors, probably to an orthosteric site: anandamide, 2-arachidonoylglycerol, noladin ether, dihomo-γ-linolenoylethanolamide, virodhamine, oleamide, docosahexaenoylethanolamide, eicosapentaenoylethanolamide, sphingosine, docosatetraenoylethanolamide, N-arachidonoyldopamine, N-oleoyldopamine and haemopressin.

In addition, this review describes in vitro findings that suggest that the first eight of these compounds can activate CB1 and sometimes also CB2 receptors and that another two of these compounds are CB1 receptor antagonists (sphingosine) or antagonists/inverse agonists (haemopressin).

Evidence for the existence of at least three allosteric endocannabinoids is also presented. These endogenous compounds appear to target allosteric sites on cannabinoid receptors in vitro, either as negative allosteric modulators of the CB1 receptor (pepcan-12 and pregnenolone) or as positive allosteric modulators of this receptor (lipoxin A4) or of the CB2 receptor (pepcan-12).

Also discussed are current in vitro data that indicate the extent to which some established or putative orthosteric endocannabinoids seem to target non-cannabinoid receptors and ion channels, particularly at concentrations at which they have been found to interact with CB1 or CB2 receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/26408156

G protein-coupled receptor 18: A potential role for endocannabinoid signalling in metabolic dysfunction.

Posted on September 5, 2015 by David

“Endocannabinoids are products of dietary fatty acids that are modulated by an alteration in food intake levels.

Overweight and obese individuals have substantially higher circulating levels of the arachidonic acid-derived endocannabinoids, anandamide and 2-arachidonoyl glycerol, and show an altered pattern of cannabinoid receptor expression.

These cannabinoid receptors are part of a large family of G protein-coupled receptors (GPCRs).

GPCRs are major therapeutic targets for various diseases within the cardiovascular, neurological, gastrointestinal and endocrine systems, as well as metabolic disorders such as obesity and type 2 diabetes mellitus.

Obesity is considered a state of chronic low grade inflammation elicited by an immunological response.

Interestingly, the newly deorphanised G protein-coupled receptor GPR18, which is considered to be a putative cannabinoid receptor, is proposed to have an immunological function.

In this review, the current scientific knowledge on GPR18 is explored including its localisation, signalling pathways and pharmacology.

Importantly, the involvement of nutritional factors and potential dietary regulation of GPR18 and its (patho)physiological roles are described.

Further research on this receptor and its regulation will enable a better understanding of the complex mechanisms of GPR18 and its potential as a novel therapeutic target for treating metabolic disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26337420

The Endocannabinoid System and its Modulation by Phytocannabinoids

Posted on August 15, 2015 by David

“The endocannabinoid system is currently defined as the ensemble of the two 7-transmembrane-domain and G protein-coupled receptors for Δ9-tetrahydrocannabinol (but not for most other plant cannabinoids or phytocannabinoids)—cannabinoid receptor type-1 (CB1R) and cannabinoid receptor type-2 (CB2R); their two most studied endogenous ligands, the “endocannabinoids” N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol (2-AG); and the enzymes responsible for endocannabinoid metabolism.

However, anandamide and 2-AG, and also the phytocannabinoids, have more molecular targets than just CB1R and CB2R.

Furthermore, the endocannabinoids, like most other lipid mediators, have more than just one set of biosynthetic and degrading pathways and enzymes, which they often share with “endocannabinoid-like” mediators that may or may not interact with the same proteins as Δ9-tetrahydrocannabinol and other phytocannabinoids.

In some cases, these degrading pathways and enzymes lead to molecules that are not inactive and instead interact with other receptors.

Finally, some of the metabolic enzymes may also participate in the chemical modification of molecules that have very little to do with endocannabinoid and cannabinoid targets.

Here, we review the whole world of ligands, receptors, and enzymes, a true “endocannabinoidome”, discovered after the cloning of CB1R and CB2R and the identification of anandamide and 2-AG, and its interactions with phytocannabinoids.”

http://www.ncbi.nlm.nih.gov/pubmed/26271952

http://link.springer.com/article/10.1007%2Fs13311-015-0374-6