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

Experimental cannabinoid 2 receptor inhibition in CNS injury-induced immunodeficiency syndrome.

“Severe central nervous system (CNS) injury, such as stroke, traumatic brain injury or spinal cord injury, is known to increase susceptibility to infections. The increased susceptibility to infection is due to an impaired immune response and is referred to as CNS injury-induced immune deficiency syndrome (CIDS).

The cannabinoid 2 receptor (CB2 R) on immune cells presents a potential therapeutic target in CIDS as activation of this receptor has been shown to be involved in immunosuppression.

Our findings suggest that inhibition of CB2 R signaling in animals with CIDS challenged with endotoxin restored peripheral leukocyte recruitment without detrimental impact on infarct size.

We conclude that the endocannabinoid system is involved in the impaired immune response following CNS injury and future studies should further explore the CB2 R pathway in order to develop novel therapies for CIDS.”

http://www.ncbi.nlm.nih.gov/pubmed/26999797

β-caryophyllene, a dietary cannabinoid, complexed with β-cyclodextrin produced anti-hyperalgesic effect involving the inhibition of Fos expression in superficial dorsal horn.

“Evaluate the anti-hyperalgesic effect of the complex containing β-caryophyllene (βCP) and β-cyclodextrin (βCD) in a non-inflammatory chronic muscle pain mice model and investigated its action on superficial dorsal horn of the lumbar spinal cord.

The characterization tests indicated that βCP were efficiently incorporated into βCD. The oral treatment with βCP-βCD, at all doses tested, produced a significant reduction on mechanical hyperalgesia and a significant increase in muscle withdrawal thresholds, without produce any alteration in force. In addition, βCP-βCD was able to significantly decrease Fos expression in the superficial dorsal horn.

SIGNIFICANCE:

Thus, βCP-βCD attenuates the non-inflammatory chronic muscle pain in mice and inhibits the Fos expression in the lumbar spinal cord.”

http://www.ncbi.nlm.nih.gov/pubmed/26883973

“β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.”  http://www.ncbi.nlm.nih.gov/pubmed/23138934

“β (beta)-cyclodextrin: 7-membered sugar ring molecule”  https://en.wikipedia.org/wiki/Cyclodextrin

Effect of cannabinoids on CGRP release in the isolated rat lumbar spinal cord.

“Cannabinoids produce analgesia through a variety of mechanisms.

It has been proposed that one mechanism is by modulating the release of CGRP in the spinal cord pain pathways.

Previous studies have reported that cannabinoids, particularly CB2 receptor agonists, can modulate CGRP release in the isolated rat spinal cord.

These results question the role of spinal cord cannabinoid receptors in the regulation of CGRP signalling.”

http://www.ncbi.nlm.nih.gov/pubmed/26762784

CB1 cannabinoid receptor enrichment in the ependymal region of the adult human spinal cord

Figure 1

“Cannabinoids are involved in the regulation of neural stem cell biology and their receptors are expressed in the neurogenic niches of adult rodents.

In the spinal cord of rats and mice, neural stem cells can be found in the ependymal region, surrounding the central canal, but there is evidence that this region is largely different in adult humans: lacks a patent canal and presents perivascular pseudorosettes, typically found in low grade ependymomas.

Using Laser Capture Microdissection, Taqman gene expression assays and immunohistochemistry, we have studied the expression of endocannabinoid system components (receptors and enzymes) at the human spinal cord ependymal region.

We observe that ependymal region is enriched in CB1 cannabinoid receptor, due to high CB1 expression in GFAP+ astrocytic domains. However, in human spinal cord levels that retain central canal patency we found ependymal cells with high CB1 expression, equivalent to the CB1HIGH cell subpopulation described in rodents.

Our results support the existence of ependymal CB1HIGH cells across species, and may encourage further studies on this subpopulation, although only in cases when central canal is patent. In the adult human ependyma, which usually shows central canal absence, CB1 may play a different role by modulating astrocyte functions.”

http://www.nature.com/articles/srep17745

CB 1Cannabinoid Receptor Agonist Inhibits Matrix Metalloproteinase Activity in Spinal Cord Injury: A Possible Mechanism of Improved Recovery.

“Increased matrix metalloproteinase (MMP) activity contributes to glial scar formation that inhibits the repair path after spinal cord injury (SCI). We examined whether treatment with N-​(2-​chloroethyl)-​5Z,​8Z,​11Z,​14Z-​eicosatetraenamide (ACEA), a selective synthetic cannabinoid receptor (CB1R) agonist, inhibits MMP and improves functional and histological recovery in a mouse spinal cord compression injury model…

Collectively these data demonstrate that post-injury CB1R agonism can improve SCI outcome and also indicate marked attenuation of MMP-9 proteolytic enzyme activity as a biochemical mechanism.”

http://www.ncbi.nlm.nih.gov/pubmed/25881484

http://www.thctotalhealthcare.com/category/spinal-cord-injury/

Cannabinoids to treat spinal cord injury.

“Spinal Cord Injury (SCI) is a devastating condition for which there is no standard treatment beyond rehabilitation strategies. In this review, we discuss the current knowledge on the use of cannabinoids to treat this condition.

The endocannabinoid system is expressed in the intact spinal cord, and it is dramatically upregulated after lesion. Endogenous activation of this system counteracts secondary damage following SCI, and treatments with endocannabinoids or synthetic cannabinoid receptor agonists promote a better functional outcome in experimental models.

The use of cannabinoids in SCI is a new research field and many questions remain open. Here, we discuss caveats and suggest some future directions that may help to understand the role of cannabinoids in SCI and how to take advantage of this system to regain functions after spinal cord damage.”

http://www.ncbi.nlm.nih.gov/pubmed/25805333

http://www.thctotalhealthcare.com/category/spinal-cord-injury/

Protective effects of cannabidiol on lesion-induced intervertebral disc degeneration.

“Disc degeneration is a multifactorial process that involves hypoxia, inflammation, neoinnervation, accelerated catabolism, and reduction in water and glycosaminoglycan content…

Cannabidiol (CBD) is the major nonpsychotropic phytocannabinoid of Cannabis sativa (up to 40% of Cannabis extracts). Contrary to most cannabinoids, CBD does not produce psychotomimetic or cognitive effects. Interesting, in the last years it has been suggest that CBD produces a plethora of others pharmacological effects, including antioxidant, neuroprotective, anti-proliferative, anti-anxiety, hypnotic and antiepileptic, anti-nausea, anti-ischemic, anti-hyperalgesic, and anti-inflammatory…

The present study investigated the effects of cannabidiol intradiscal injection in the coccygeal intervertebral disc degeneration induced by the needle puncture model using magnetic resonance imaging (MRI) and histological analyses…

 Cannabidiol significantly attenuated the effects of disc injury induced by the needle puncture. Considering that cannabidiol presents an extremely safe profile and is currently being used clinically, these results suggest that this compound could be useful in the treatment of intervertebral disc degeneration.

 In summary our study revealed anti-degenerative effects of intradiscal microinjection of CBD 120 nmol. CBD represents one of the most promising candidates present in the Cannabis sativa plant for clinical use due to its remarkable lack of cognitive or psychotomimetic actions.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4269422/

http://www.thctotalhealthcare.com/category/spinal-cord-injury/

Cannabinoid CB2 receptor (CB2R) stimulation delays rubrospinal mitochondrial-dependent degeneration and improves functional recovery after spinal cord hemisection by ERK1/2 inactivation.

“Spinal cord injury (SCI) is a devastating condition… Modulation of the endocannabinoid system (ECS) counteracts neurodegeneration, and pharmacological modulation of type-2 cannabinoid receptor (CB2R) is a promising therapeutic target for several CNS pathologies, including SCI…

These findings implicate the ECS, particularly CB2R, as part of the endogenous neuroprotective response that is triggered after SCI.

Thus, CB2R modulation might represent a promising therapeutic target that lacks psychotropic effects and can be used to exploit ECS-based approaches to counteract neuronal degeneration.”

http://www.ncbi.nlm.nih.gov/pubmed/25188514

http://www.thctotalhealthcare.com/category/spinal-cord-injury/

Therapeutic potential of cannabinoid medicines.

Drug Testing and Analysis

“Cannabis was extensively used as a medicine throughout the developed world in the nineteenth century but went into decline early in the twentieth century ahead of its emergence as the most widely used illicit recreational drug later that century. Recent advances in cannabinoid pharmacology alongside the discovery of the endocannabinoid system (ECS) have re-ignited interest in cannabis-based medicines.

The ECS has emerged as an important physiological system and plausible target for new medicines. Its receptors and endogenous ligands play a vital modulatory role in diverse functions including immune response, food intake, cognition, emotion, perception, behavioural reinforcement, motor co-ordination, body temperature, wake/sleep cycle, bone formation and resorption, and various aspects of hormonal control. In disease it may act as part of the physiological response or as a component of the underlying pathology.

In the forefront of clinical research are the cannabinoids delta-9-tetrahydrocannabinol and cannabidiol, and their contrasting pharmacology will be briefly outlined. The therapeutic potential and possible risks of drugs that inhibit the ECS will also be considered. This paper will then go on to review clinical research exploring the potential of cannabinoid medicines in the following indications: symptomatic relief in multiple sclerosis, chronic neuropathic pain, intractable nausea and vomiting, loss of appetite and weight in the context of cancer or AIDS, psychosis, epilepsy, addiction, and metabolic disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/24006213

http://onlinelibrary.wiley.com/doi/10.1002/dta.1529/abstract