ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.

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“Cannabis sativa is also popularly known as marijuana. It is being cultivated and used by man for recreational and medicinal purposes from many centuries.

Study of cannabinoids was at bay for very long time and its therapeutic value could not be adequately harnessed due to its legal status as proscribed drug in most of the countries.

The research of drugs acting on endocannabinoid system has seen many ups and down in recent past. Presently, it is known that endocannabinoids has role in pathology of many disorders and they also serve “protective role” in many medical conditions.

Several diseases like emesis, pain, inflammation, multiple sclerosis, anorexia, epilepsy, glaucoma, schizophrenia, cardiovascular disorders, cancer, obesity, metabolic syndrome related diseases, Parkinson’s disease, Huntington’s disease, Alzheimer’s disease and Tourette’s syndrome could possibly be treated by drugs modulating endocannabinoid system.

Presently, cannabinoid receptor agonists like nabilone and dronabinol are used for reducing the chemotherapy induced vomiting. Sativex (cannabidiol and THC combination) is approved in the UK, Spain and New Zealand to treat spasticity due to multiple sclerosis. In US it is under investigation for cancer pain, another drug Epidiolex (cannabidiol) is also under investigation in US for childhood seizures. Rimonabant, CB1 receptor antagonist appeared as a promising anti-obesity drug during clinical trials but it also exhibited remarkable psychiatric side effect profile. Due to which the US Food and Drug Administration did not approve Rimonabant in US. It sale was also suspended across the EU in 2008.

Recent discontinuation of clinical trial related to FAAH inhibitor due to occurrence of serious adverse events in the participating subjects could be discouraging for the research fraternity. Despite of some mishaps in clinical trials related to drugs acting on endocannabinoid system, still lot of research is being carried out to explore and establish the therapeutic targets for both cannabinoid receptor agonists and antagonists.

One challenge is to develop drugs that target only cannabinoid receptors in a particular tissue and another is to invent drugs that acts selectively on cannabinoid receptors located outside the blood brain barrier. Besides this, development of the suitable dosage forms with maximum efficacy and minimum adverse effects is also warranted.

Another angle to be introspected for therapeutic abilities of this group of drugs is non-CB1 and non-CB2 receptor targets for cannabinoids.

In order to successfully exploit the therapeutic potential of endocannabinoid system, it is imperative to further characterize the endocannabinoid system in terms of identification of the exact cellular location of cannabinoid receptors and their role as “protective” and “disease inducing substance”, time-dependent changes in the expression of cannabinoid receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/27086601

Cannabinoids and autoimmune diseases: A systematic review.

“Cannabinoids have shown to have a variety effects on body systems. Through CB1 and CB2 receptors, amongst other, they exert an effect by modulating neurotransmitter and cytokine release.

Current research in the role of cannabinoids in the immune system shows that they possess immunosuppressive properties. They can inhibit proliferation of leucocytes, induce apoptosis of T cells and macrophages and reduce secretion of pro-inflammatory cytokines.

In mice models, they are effective in reducing inflammation in arthritis, multiple sclerosis, have a positive effect on neuropathic pain and in type 1 diabetes mellitus.

They are effective as treatment for fibromyalgia and have shown to have anti-fibrotic effect in scleroderma.

Studies in human models are scarce and not conclusive and more research is required in this field.

Cannabinoids can be therefore promising immunosuppressive and anti-fibrotic agents in the therapy of autoimmune disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26876387

http://www.thctotalhealthcare.com/category/autoimmune-disease/

Cannabidiol limits Tcell-mediated chronic autoimmune myocarditis: implications to autoimmune disorders and organ transplantation.

“Myocarditis is a major cause of heart failure and sudden cardiac death in young adults and adolescents. Many cases of myocarditis are associated with autoimmune processes in which cardiac myosin is a major autoantigen.

Conventional immunosuppressive therapies often provide unsatisfactory results and are associated with adverse toxicities during the treatment of autoimmune myocarditis.

Cannabidiol (CBD) is a non-psychoactive constituent of Marijuana which exerts antiinflammatory effects independent from classical cannabinoid receptors.

Recently 80 clinical trials have been reported investigating the effects of CBD in various diseases from inflammatory bowel disease to graft-versus-host disease.

CBD-based formulations are used for the management of multiple sclerosis in numerous countries, and CBD also received FDA approval for the treatment of refractory childhood epilepsy and glioblastoma multiforme.

Herein, using a well-established mouse model of experimental autoimmune myocarditis (EAM) induced by immunization with cardiac myosin emmulsified in adjuvant resulting in T cell-mediated inflammation, cardiomyocyte cell death, fibrosis and myocardial dysfunction, we studied the potential beneficial effects of CBD…

CBD may represent a promising novel treatment for management of autoimmune myocarditis and possibly other autoimmune disorders, and organ transplantation.”

http://www.ncbi.nlm.nih.gov/pubmed/26772776

The disease-modifying effects of a Sativex-like combination of phytocannabinoids in mice with experimental autoimmune encephalomyelitis are preferentially due to Δ9-tetrahydrocannabinol acting through CB1 receptors.

“Sativex®, an equimolecular combination of Δ9-tetrahydrocannabinol-botanical drug substance (Δ9-THC-BDS) and cannabidiol-botanical drug substance (CBD-BDS), is a licensed medicine that may be prescribed for alleviating specific symptoms of multiple sclerosis (MS) such as spasticity and pain.

However, further evidence suggest that it could be also active as disease-modifying therapy given the immunomodulatory, anti-inflammatory and cytoprotective properties of their two major components.

In this study, we investigated this potential in the experimental autoimmune encephalitis (EAE) model of MS in mice.

We compared the effect of a Sativex-like combination of Δ9-THC-BDS (10mg/kg) and CBD-BDS (10mg/kg) with Δ9-THC-BDS (20mg/kg) or CBD-BDS (20mg/kg) administered separately by intraperitoneal administration to EAE mice.

Treatments were initiated at the time that symptoms appear and continued up to the first relapse of the disease.

The results show that the treatment with a Sativex-like combination significantly improved the neurological deficits typical of EAE mice, in parallel with a reduction in the number and extent of cell aggregates present in the spinal cord which derived from cell infiltration to the CNS.

These effects were completely reproduced by the treatment with Δ9-THC-BDS alone, but not by CBD-BDS alone which only delayed the onset of the disease without improving disease progression and reducing the cell infiltrates in the spinal cord.

Next, we investigated the potential targets involved in the effects of Δ9-THC-BDS by selectively blocking CB1 or PPAR-γ receptors, and we found a complete reversion of neurological benefits and the reduction in cell aggregates only with rimonabant, a selective CB1 receptor antagonist.

Collectively, our data support the therapeutic potential of Sativex as a phytocannabinoid formulation capable of attenuating EAE progression, and that the active compound was Δ9-THC-BDS acting through CB1 receptors.”

A new formulation of cannabidiol in cream shows therapeutic effects in a mouse model of experimental autoimmune encephalomyelitis.

“The present study was designed to investigate the efficacy of a new formulation of alone, purified cannabidiol (CBD) (>98 %), the main non-psychotropic cannabinoid of Cannabis sativa, as a topical treatment in an experimental model of autoimmune encephalomyelitis (EAE), the most commonly used model for multiple sclerosis (MS)…

All these data suggest an interesting new profile of CBD that could lead to its introduction in the clinical management of MS and its associated symptoms at least in association with current conventional therapy.”

http://www.ncbi.nlm.nih.gov/pubmed/26489494

“Summarizing, we have shown that the topical administration of CBD can protect against the cascade of events (inflammation, oxidative injury and neuronal cell death) associated to the induction of EAE. Of note, topical CBD application was able to recover the hind limb lost sensitivity. This observation provides a rationale for evaluating its clinical translation that might represent a new concept in the management of MS. Finally, we suggest that CBD, devoid of psychoactive activity, could be potentially, safe and effective non invasive alternatives for alleviating neuroinflammation and neurodegeneration.”  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4618347/

HU-446 and HU-465, derivatives of the non-psychoactive cannabinoid cannabidiol, decrease the activation of encephalitogenic T cells.

“Cannabidiol (CBD), the non-psychoactive cannabinoid, has been previously shown by us to decrease peripheral inflammation and neuroinflammation in mouse experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS).

Here we have studied the anti-inflammatory effects of newly synthesized derivatives of natural (-)-CBD ((-)-8,9-dihydro-7-hydroxy-CBD; HU-446) and of synthetic (+)-CBD ((+)-8,9-dihydro-7-hydroxy-CBD; HU-465)…

These results suggest that HU-446 and HU-465 have anti-inflammatory potential in inflammatory and autoimmune diseases. ”

http://www.ncbi.nlm.nih.gov/pubmed/26259697

Preclinical evaluation of SMM-189, a cannabinoid receptor 2-specific inverse agonist.

“Cannabinoid receptor 2 agonists and inverse agonists are emerging as new therapeutic options for a spectrum of autoimmune-related disease.

Of particular interest, is the ability of CB2 ligands to regulate microglia function in neurodegenerative diseases and traumatic brain injury.

We have previously reported the receptor affinity of 3′,5′-dichloro-2,6-dihydroxy-biphenyl-4-yl)-phenyl-methanone (SMM-189) and the characterization of the beneficial effects of SMM-189 in the mouse model of mild traumatic brain injury.

Herein, we report the further characterization of SMM-189 as a potent and selective CB2 inverse agonist, which acts as a noncompetitive inhibitor of CP 55,940.

The ability of SMM-189 to regulate microglial activation, in terms of chemokine expression and cell morphology, has been determined.

Finally, we have determined that SMM-189 possesses acceptable biopharmaceutical properties indicating that the triaryl class of CB2 inverse agonists are viable compounds for continued preclinical development for the treatment of neurodegenerative disorders and traumatic brain injury.”

http://www.ncbi.nlm.nih.gov/pubmed/26196013

Cannabinoids Inhibit T-cells via Cannabinoid Receptor 2 in an in vitro Assay for Graft Rejection, the Mixed Lymphocyte Reaction

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“Cannabinoids are known to have anti-inflammatory and immunomodulatory properties.

Cannabinoid receptor 2 (CB2) is expressed mainly on leukocytes and is the receptor implicated in mediating many of the effects of cannabinoids on immune processes.

This study tested the capacity of Δ9-tetrahydrocannabinol (Δ9-THC) and of two CB2-selective agonists to inhibit the murine Mixed Lymphocyte Reaction (MLR), an in vitro correlate of graft rejection following skin and organ transplantation. Both CB2-selective agonists and Δ9-THC significantly suppressed the MLR in a dose dependent fashion…

Together, these data support the potential of this class of compounds as useful therapies to prolong graft survival in transplant patients.

Cannabinoids were reported to have effects on immune responses as early as the 1970s, but the basis for this activity was not understood until the cannabinoid receptors were cloned

Ideally, the anatomically disparate expression of CB1 and CB2 would allow for the use of compounds selective for CB2, and thus eliminate the unwanted psychoactive effects from CB1 activation, while maintaining the anti-inflammatory and immunosuppressive properties.

CB2-selective cannabinoids have been proposed as possible candidates to block graft rejection.

The results presented in this paper show that Δ9-THC, a mixed CB1/CB2 agonist, and two CB2-selective agonists can inhibit the Mixed Lymphocyte Reaction (MLR), an in vitro correlate of organ and skin graft rejection.”

 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3864984/

Cannabidiol, a non-psychoactive cannabinoid, leads to EGR2-dependent anergy in activated encephalitogenic T cells.

“Cannabidiol (CBD), the main non-psychoactive cannabinoid, has been previously shown by us to ameliorate clinical symptoms and to decrease inflammation in myelin oligodendrocyte glycoprotein (MOG)35-55-induced mouse experimental autoimmune encephalomyelitis model of multiple sclerosis as well as to decrease MOG35-55-induced T cell proliferation and IL-17 secretion. However, the mechanisms of CBD anti-inflammatory activities are unclear.

We found that CBD leads to upregulation of CD69 and lymphocyte-activation gene 3 (LAG3) regulatory molecules on CD4+CD25-accessory T cells. This subtype of CD4+CD25-CD69+LAG3+ T cells has been recognized as induced regulatory phenotype promoting anergy in activated T cells.

Indeed, we observed that CBD treatment results in upregulation of EGR2 (a key T cell anergy inducer) mRNA transcription in stimulated TMOG cells. This was accompanied by elevated levels of anergy promoting genes such as IL-10 (anti-inflammatory cytokine), STAT5 (regulatory factor), and LAG3 mRNAs, as well as of several enhancers of cell cycle arrest (such as Nfatc1, Casp4, Cdkn1a, and Icos).

Moreover, CBD exposure leads to a decrease in STAT3 and to an increase in STAT5 phosphorylation in TMOG cells, positive and negative regulators of Th17 activity, respectively. In parallel, we observed decreased levels of major histocompatibility complex class II (MHCII), CD25, and CD69 on CD19+ B cells following CBD treatment, showing diminished antigen presenting capabilities of B cells and reduction in their pro-inflammatory functions.

CONCLUSIONS:

Our data suggests that CBD exerts its immunoregulatory effects via induction of CD4+CD25-CD69+LAG3+ cells in MOG35-55-activated APC/TMOG co-cultures. This is accompanied by EGR2-dependent anergy of stimulated TMOG cells as well as a switch in their intracellular STAT3/STAT5 activation balance leading to the previously observed decrease in Th17 activity.”

http://www.ncbi.nlm.nih.gov/pubmed/25880134

Full-text: http://www.jneuroinflammation.com/content/12/1/52

Regulation of inflammation by cannabinoids, the endocannabinoids 2-arachidonoyl-glycerol and arachidonoyl-ethanolamide, and their metabolites.

“2-Arachidonoyl-glycerol (2-AG) and arachidonyl-ethanolamide (AEA) are endocannabinoids that have been implicated in many physiologic disorders, including obesity, metabolic syndromes, hepatic diseases, pain, neurologic disorders, and inflammation.

Their immunomodulatory effects are numerous and are not always mediated by cannabinoid receptors, reflecting the presence of an arachidonic acid (AA) molecule in their structure, the latter being the precursor of numerous bioactive lipids that are pro- or anti-inflammatory.

2-AG and AEA can thus serve as a source of AA but can also be metabolized by most eicosanoid biosynthetic enzymes, yielding additional lipids.

In this regard, enhancing endocannabinoid levels by using endocannabinoid hydrolysis inhibitors is likely to augment the levels of these lipids that could regulate inflammatory cell functions.

This review summarizes the metabolic pathways involved in the biosynthesis and metabolism of AEA and 2-AG, as well as the biologic effects of the 2-AG and AEA lipidomes in the regulation of inflammation.”

http://www.ncbi.nlm.nih.gov/pubmed/25877930