Synthetic cannabinoid receptor agonists and antagonists: implication in CNS disorders.

“Since the discovery of the cannabinoid receptors, numerous studies associate the endocannabinoid system with several physiological and pathological processes including cancer, appetite, fertility, memory, neuropathic and inflammatory pain, obesity, and neurodegenerative diseases.

Over the last two decades, several researches have been dedicated extensively on the cannabinoid receptors ligands since the direct activation of cannabinoid receptors results in several beneficial effects, in the brain and in the periphery.

During past years, cannabinoid CB1 and CB2 receptor ligands from plants or lab were rapidly developed and then various new structures were reported to be cannabinoids.

The CB1 and CB2 receptor ligands offer several therapeutic opportunities for several CNS-related diseases.

Based on the scientific literature, this review provides an overview of CB1 and CB2 receptor synthetic ligands obtained from drug research and in particular those synthesized for therapeutic purposes and potential clinical applications for central nervous system disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/27193072

Difference and Influence of Inactive and Active States of Cannabinoid Receptor Subtype CB2: From Conformation to Drug Discovery.

“Cannabinoid receptor 2 (CB2), a G protein-coupled receptor (GPCR), is a promising target for the treatment of neuropathic pain, osteoporosis, immune system, cancer, and drug abuse.”

http://www.ncbi.nlm.nih.gov/pubmed/27186994

Functional selectivity of CB2 cannabinoid receptor ligands at a canonical and non-canonical pathway.

“The CB2 cannabinoid receptor remains a tantalizing, but unrealized therapeutic target. CB2 receptor ligands belong to varied structural classes and display extreme functional selectivity. Here we have screened diverse CB2 receptor ligands at canonical (inhibition of adenylyl cyclase) and non-canonical (arrestin recruitment) pathways. The non-classical cannabinoid, CP55940 was the most potent agonist for both pathways, while the classical cannabinoid ligand JWH133 was the most efficacious agonist amongst all the ligands profiled in cyclase assays. In the cyclase assay, other classical cannabinoids showed little (Δ9THC, KM233) to no efficacy (L759633 and L759656). Most aminoalkylindoles including WIN55212-2 were moderate efficacy agonists. The cannabilactone AM1710 was equi-efficacious to CP55940 to inhibit adenylyl cyclase, albeit with lower potency. In the arrestin recruitment assays, all classical cannabinoid ligands failed to recruit arrestins, indicating a bias towards G protein coupling for this class of compound. All aminoalkylindoles tested, except for WIN55212-2 and UR144, failed to recruit arrestin. WIN55212-2 was a low efficacy agonist for arrestin recruitment, while UR144 was arrestin biased with no significant inhibition of cyclase. Endocannabinoids were G protein biased with no arrestin recruitment. The diarylpyrazole antagonist, SR144528 was an inverse agonist in cyclase and arrestin recruitment assays while the aminoalkylindole AM630 and carboxamide JTE907 were inverse agonists in cyclase but low efficacy agonists in arrestin recruitment assays. Thus CB2 receptor ligands display strong and varied functional selectivity at both pathways. Therefore extreme care must be exercised when using these compounds to infer the role of CB2 receptors in vivo.”

http://www.ncbi.nlm.nih.gov/pubmed/27194477

Opposite roles of cannabinoid receptors 1 and 2 in hepatocarcinogenesis.

“The endocannabinoid system (ECS) exerts key roles in the development of liver fibrosis and fatty liver, two diseases that promote the development of hepatocellular carcinoma (HCC).

Although cannabinoids exert potent antitumour effects in vitro, the contribution of the ECS to carcinogenesis in vivo remains elusive.

CONCLUSIONS:

Similar to their role in fibrogenesis, CB1 and CB2 exert opposite effects on hepatocarcinogenesis and may provide novel therapeutic targets.”

http://www.ncbi.nlm.nih.gov/pubmed/27196571

A Central Move for CB2 Receptors.

“The function of the CB2 cannabinoid receptor in the brain has long been a matter of debate. In this issue of Neuron, Stempel et al. (2016) describe a mechanism whereby endocannabinoid production leads to a cell-intrinsic hyperpolarization that controls self activity.”

http://www.ncbi.nlm.nih.gov/pubmed/27196970

MicroRNA let-7d is a target of cannabinoid CB1 receptor and controls cannabinoid signaling.

“Cannabinoid CB1 receptor, the molecular target of endocannabinoids and cannabis active components, is one of the most abundant metabotropic receptors in the brain. Cannabis is widely used for both recreational and medicinal purposes.

Despite the ever-growing fundamental roles of microRNAs in the brain, the possible molecular connections between the CB1 receptor and microRNAs are surprisingly unknown. Here, by using reporter gene constructs that express interaction sequences for microRNAs in human SH-SY5Y neuroblastoma cells, we show that CB1 receptor activation enhances the expression of several microRNAs, including let-7d.

Taken together, these findings provide the first evidence for a bidirectional link between the CB1 receptor and a microRNA, namely let-7d, and thus unveil a new player in the complex process of cannabinoid action.”

http://www.ncbi.nlm.nih.gov/pubmed/27179908

Interactions between cannabinoid receptor agonists and mu opioid receptor agonists in rhesus monkeys discriminating fentanyl.

“Cannabinoid receptor agonists such as delta-9-tetrahydrocannabinol (Δ9-THC) enhance some (antinociceptive) but not other (positive reinforcing) effects of mu opioid receptor agonists, suggesting that cannabinoids might be combined with opioids to treat pain without increasing, and possibly decreasing, abuse.

These data indicate that the discriminative stimulus effects of nalbuphine are more sensitive to attenuation by cannabinoids than those of fentanyl. That the discriminative stimulus effects of some opioids are more susceptible to modification by drugs from other classes has implications for developing maximally effective therapeutic drug mixtures with reduced abuse liability.”

http://www.ncbi.nlm.nih.gov/pubmed/27184925

Phytocannabinoids and cannabimimetic drugs: recent patents in central nervous system disorders.

“Starting from the chemical structure of phytocannabinoids, isolated from Cannabis sativa plant, research groups designed numerous cannabimimetic drugs.

These compounds according to their activities can be partial, full agonists and antagonists of cannabinoid receptors.

Anecdotal reports and scientific studies described beneficial properties of cannabinoids and their derivatives in several pathological conditions like neurological and neuropsychiatric disorders, and in many other diseases ranging from cancer, atherosclerosis, stroke, hypertension, inflammatory related disorders, and autoimmune diseases.

The cannabinoid CB1 receptor was considered particularly interesting for therapeutic approaches in neurological diseases, because primarily expressed by neurons of the central nervous system. In many experimental models, these drugs act via this receptor, however, CB1 receptor independent mechanisms have been also described. Furthermore, endogenous ligands of cannabinoid receptors, the endocannabinoids, are potent modulators of the synaptic function in the brain. In neurological diseases, numerous studies reported modulation of the levels of endocannabinoids according to the phase of the disease and its progression.

CONCLUSIONS:

Finally, although the study of the mechanisms of action of these compounds is still unsolved, many reports and patents strongly suggest therapeutic potential of these compounds in neurological diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/27184693

Beyond Cannabis: Plants and the Endocannabinoid System.

“Plants have been the predominant source of medicines throughout the vast majority of human history, and remain so today outside of industrialized societies.

One of the most versatile in terms of its phytochemistry is cannabis, whose investigation has led directly to the discovery of a unique and widespread homeostatic physiological regulator, the endocannabinoid system.

While it had been the conventional wisdom until recently that only cannabis harbored active agents affecting the endocannabinoid system, in recent decades the search has widened and identified numerous additional plants whose components stimulate, antagonize, or modulate different aspects of this system.

These include common foodstuffs, herbs, spices, and more exotic ingredients: kava, chocolate, black pepper, and many others that are examined in this review.”

http://www.ncbi.nlm.nih.gov/pubmed/27179600

Potentiation of cannabinoid-induced cytotoxicity in Mantle Cell Lymphoma through modulation of ceramide metabolism

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“Ceramide accumulation is a widely described event in cancers after various treatments.

Ceramide levels are elevated in Mantle Cell Lymphoma (MCL) cells following treatment with cannabinoids.

In previous publications we and others observed that induction of ceramide accumulation by cannabinoids leads to apoptosis in MCL, glioma and pancreatic cancer.

Here, we investigated the pathways of ceramide accumulation in the MCL cell line Rec-1 using the stable endocannabinoid analogue R(+)-methanandamide (R-MA).

Our findings suggest that R-MA induces cell death in MCL via CB1-mediated upregulation of the de novo ceramide synthesis pathway.

This is the first study showing that the cytotoxic effect of a cannabinoid can be enhanced by modulation of ceramide metabolism.

The results suggest that interference with ceramide conversion may provide a tool to enhance the targeted cell death-promoting effects of cannabinoids in MCL and other malignant lymphomas overexpressing the CB1 receptor.

Cannabinoids have been suggested as a new non-toxic therapeutic option for cancer treatment.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3077284/