Tag Archives: agonists

Potent immunomodulatory activity of a highly selective cannabinoid CB2 agonist on immune cells from healthy subjects and patients with multiple sclerosis.

Posted on by
Reply

Image result for journal of neuroimmunology

“COR167, a novel CB2-selective high affinity agonist, was found to significantly inhibit, in a dose-dependent manner, the proliferation of both peripheral blood mononuclear cells and myelin basic protein-reactive T cell lines from normal healthy subjects and patients with relapsing-remitting multiple sclerosis (MS). In MS, a significantly higher inhibition was observed in patients on treatment with disease modifying drugs compared to those naive to treatment. The inhibitory activity of COR167 was exerted through a mixed mechanism involving atypical and incomplete shift of Th1 phenotype towards Th2 phenotype associated with slight reduction of IL-4 and IL-5 as well as strongly reduced levels of Th17-related cytokines. COR167 was also able to reduce in vitro migration of stimulated immunocompetent cells through human brain endothelium associated with a significant reduction of levels of several chemokines. These findings demonstrate that COR167 exerts potent immunomodulatory effects and confirm the cannabinoid CB2 receptor as a novel pharmacological target to counteract neuroinflammation.”

https://www.ncbi.nlm.nih.gov/pubmed/28041663

Synergistic attenuation of chronic pain using mu opioid and cannabinoid receptor 2 agonists.

Posted on by
Reply

Image result for neuropharmacology journal

“The misuse of prescription opiates is on the rise with combination therapies (e.g. acetaminophen or NSAIDs) resulting in severe liver and kidney damage. In recent years, cannabinoid receptors have been identified as potential modulators of pain and rewarding behaviors associated with cocaine, nicotine and ethanol in preclinical models. Yet, few studies have identified whether mu opioid agonists and CB2 agonists act synergistically to inhibit chronic pain while reducing unwanted side effects including reward liability.

We determined if analgesic synergy exists between the mu-opioid agonist morphine and the selective CB2 agonist, JWH015, in rodent models of acute and chronic inflammatory, post-operative, and neuropathic pain using isobolographic analysis. We also investigated if the MOR-CB2 agonist combination decreased morphine-induced conditioned place preference (CPP) and slowing of gastrointestinal transit. Co-administration of morphine with JWH015 synergistically inhibited preclinical inflammatory, post-operative and neuropathic-pain in a dose- and time-dependent manner; no synergy was observed for nociceptive pain. Opioid-induced side effects of impaired gastrointestinal transit and CPP were significantly reduced in the presence of JWH015.

Here we show that MOR + CB2 agonism results in a significant synergistic inhibition of preclinical pain while significantly reducing opioid-induced unwanted side effects.

The opioid sparing effect of CB2 receptor agonism strongly supports the advancement of a MOR-CB2 agonist combinatorial pain therapy for clinical trials.”

https://www.ncbi.nlm.nih.gov/pubmed/28007501

Cannabinoid 2 Receptor Agonist Improves Systemic Sensitivity to Insulin in High-Fat Diet/Streptozotocin-Induced Diabetic Mice.

Posted on by
Reply

Image result for cellular physiology and biochemistry

“The endocannabinoid signalling (ECS) system has been known to regulate glucose homeostasis.

Previous studies have suggested that the cannabinoid 2 (CB2) receptor may play a regulatory role on insulin secretion, immune modulation and insulin resistance.

Given that diabetes and insulin resistance are attributable to elevated inflammatory tone, we investigated the role of CB2 receptor on glucose tolerance and insulin sensitivity in high-fat diet (HFD)/streptozotocin (STZ)-induced mice.

Our data suggest a lipolytic role of SER601 in HFD/STZ-induced diabetic mice, which results in significant improvement of systemic insulin sensitivity.

Thus, the CB2 receptor may be considered a promising target for therapeutic development against insulin resistance and obesity-related diabetes.”

https://www.ncbi.nlm.nih.gov/pubmed/27960161

Compensatory activation of cannabinoid CB2 receptor inhibition of GABA release in the rostral ventromedial medulla (RVM) in inflammatory pain.

Posted on by
Reply

Image result for J Neurosci

“The rostral ventromedial medulla (RVM) is a relay in the descending pain modulatory system and an important site of endocannabinoid modulation of pain.

These studies demonstrate that endocannabinoid signaling to CB1- and CB2-receptors in adult RVM is altered in persistent inflammation.

The emergence of CB2 receptor function in the RVM provides additional rationale for the development of CB2 receptor-selective agonists as useful therapeutics for chronic inflammatory pain.”

https://www.ncbi.nlm.nih.gov/pubmed/27940994

Two Janus cannabinoids that are both CB2 agonists and CB1 antagonists.

Posted on by
Reply

Image result for J Pharmacol Exp Ther

“The cannabinoid signaling system includes two G protein coupled receptors, CB1 and CB2. These receptors are widely distributed throughout the body and have each been implicated in many physiologically important processes.

Though the cannabinoid signaling system has therapeutic potential, a persistent hurdle has remained the development of receptor-selective ligands. Because CB1 and CB2 are involved in diverse processes, it would be advantageous develop ligands that differentially engaging CB1 and CB2.

In summary we have determined that GW405833 and AM1710 are not only CB2 agonists but also CB1 antagonists, with distinctive and complex signaling properties. Thus experiments using these compounds must take into account their potential activity at CB1 receptors.”

https://www.ncbi.nlm.nih.gov/pubmed/27927913

Anti-inflammatory effect of cannabinoid agonist WIN55, 212 on mouse experimental colitis is related to inhibition of p38MAPK.

Posted on by
Reply

Image result for World J Gastroenterol

“To investigate the anti-inflammatory effect and the possible mechanisms of an agonist of cannabinoid (CB) receptors, WIN55-212-2 (WIN55), in mice with experimental colitis, so as to supply experimental evidence for its clinical use in future.

These results confirmed the anti-inflammatory effect and protective role of WIN55 on the mice with experimental colitis, and revealed that this agent exercises its action at least partially by inhibiting p38MAPK.

Furthermore, the results showed that SB203580, affected the expression of CB1 and CB2 receptors in the mouse colon, suggesting a close linkage and cross-talk between the p38MAPK signaling pathway and the endogenous CB system.”

https://www.ncbi.nlm.nih.gov/pubmed/27920472

Behavioral alterations in cystic fibrosis mice are prevented by cannabinoid treatment in infancy.

Posted on by
Reply

Image result for J Basic Clin Physiol Pharmacol.

“Substantial data have been accumulated regarding the molecular basis of cystic fibrosis (CF) pathogenesis, whereas the influence of biochemical impairments on brain processes has been the focus of much less attention. We have studied some behavioral parameters, such as motor activity and anxiety level, in a mice model of CF.

We have assumed that functioning of the endocannabinoid system could be impaired in CF (endocannabinoids are fatty acid derivatives, and fatty acid deficiency is considered a major factor in CF etiology). We have suggested that chronic treatment with cannabinoid receptors agonist during infancy would balance cannabinoid levels and prevent CF-related behavioral alterations.

Motor activity and anxiety level were studied in naïve adult CF mice (cftr-deficient mice) and compared with wild-type mice and to CF mice treated chronically with Δ9-tetrahydrocannabinol (Δ9-THC; endocannabinoid receptor agonist) during infancy (from days 7 to 28). Motor activity was tested in the tetrad, and level of anxiety in the plus maze, a month after cessation of treatment.

Motor activity decrease and elevated anxiety level were found in adult naïve CF mice compared with wild-type mice. CF mice treated with THC in infancy showed normal motor activity and anxiety levels in adulthood. Motor function alteration and elevated anxiety levels in CF can result from lack of CFTR-channel in neurons and disturbed activity of various brain areas, as well as being secondary and mediated by fatty acids deficiency, altered levels of endocannabinoids and their receptors.

It can be suggested that chronic treatment during infancy restores endocannabinoid function and thus prevents behavioral alterations.”

https://www.ncbi.nlm.nih.gov/pubmed/22865361

Functional selectivity at G-protein coupled receptors: Advancing cannabinoid receptors as drug targets.

Posted on by
Reply

 

Image result for Biochem Pharmacol

“The phenomenon of functional selectivity, whereby a ligand preferentially directs the information output of a G-protein coupled receptor (GPCR) along (a) particular effector pathway(s) and away from others, has redefined traditional GPCR signaling paradigms to provide a new approach to structure-based drug design.

The two principal cannabinoid receptors (CBRs) 1 and 2 belong to the class-A GPCR subfamily and are considered tenable therapeutic targets for several indications. Yet conventional orthosteric ligands (agonists, antagonists/inverse agonists) for these receptors have had very limited clinical utility due to their propensity to incite on-target adverse events. Chemically distinct classes of cannabinergic ligands exhibit signaling bias at CBRs toward individual subsets of signal transduction pathways.

In this review, we discuss the known signaling pathways regulated by CBRs and examine the current evidence for functional selectivity at CBRs in response to endogenous and exogenous cannabinergic ligands as biased agonists. We further discuss the receptor and ligand structural features allowing for selective activation of CBR-dependent functional responses. The design and development of biased ligands may offer a pathway to therapeutic success for novel CBR-targeted drugs.”

https://www.ncbi.nlm.nih.gov/pubmed/27890725

Biased Agonism of Three Different Cannabinoid Receptor Agonists in Mouse Brain Cortex

Posted on by
Reply

Image result for Front Pharmacol

“Cannabinoid receptors are able to couple to different families of G proteins when activated by an agonist drug. It has been suggested that different intracellular responses may be activated depending on the ligand.

The goal of the present study was to characterize the pattern of G protein subunit stimulation triggered by three different cannabinoid ligands, Δ9-THC, WIN55212-2, and ACEA in mouse brain cortex.

Results show that, in mouse brain cortex, cannabinoid agonists are able to significantly stimulate not only the classical inhibitory Gαi/osubunits but also other G subunits like Gαz, Gαq/11, and Gα12/13. Moreover, the specific pattern of G protein subunit activation is different depending on the ligand.

In conclusion, our results demonstrate that, in mice brain native tissue, different exogenous cannabinoid ligands are able to selectively activate different inhibitory and non-inhibitory Gα protein subtypes, through the activation of CB1 and/or CB2 receptors.

Results of the present study may help to understand the specific molecular pathways involved in the pharmacological effects of cannabinoid-derived drugs.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095132/

Cannabinoid receptors and TRPA1 on neuroprotection in a model of retinal ischemia.

Posted on by
Reply

Image result for Exp Eye Res.

“Retinal ischemia is a pathological event present in several retinopathies such as diabetic retinopathy and glaucoma, leading to partial or full blindness with no effective treatment available.

Since synthetic and endogenous cannabinoids have been studied as modulators of ischemic events in the central nervous system (CNS), the present study aimed to investigate the involvement of cannabinoid system in the cell death induced by ischemia in an avascular (chick) retina.

We observed that chick retinal treatment with a combination of WIN 55212-2 and cannabinoid receptor antagonists (either AM251/O-2050 or AM630) decreased the release of lactate dehydrogenase (LDH) induced by retinal ischemia in an oxygen and glucose deprivation (OGD) model.

Further, the increased availability of endocannabinoids together with cannabinoid receptor antagonists also had a neuroprotective effect.

Surprisingly, retinal exposure to any of these drugs alone did not prevent the release of LDH stimulated by OGD.

Since cannabinoids may also activate transient receptor potential (TRP) channels, we investigated the involvement of TRPA1 receptors (TRPA1) in retinal cell death induced by ischemic events.

We demonstrated the presence of TRPA1 in the chick retina, and observed an increase in TRPA1 content after OGD, both by western blot and immunohistochemistry.

In addition, the selective activation of TRPA1 by mustard oil (MO) did not worsen retinal LDH release induced by OGD, whereas the blockage of TRPA1 completely prevented the extravasation of cellular LDH in ischemic condition.

Hence, these results show that during the ischemic event there is an augment of TRPA1, and activation of this receptor is important in cell death induction.

The data also indicate that metabotropic cannabinoid receptors, both type 1 and 2, are not involved with the cell death found in the early stages of ischemia. Therefore, the study points to a potential role of TRPA1 as a target for neuroprotective approaches in retinal ischemia.”

https://www.ncbi.nlm.nih.gov/pubmed/27876485