The Endocannabinoid System: A Potential Target for the Treatment of Various Diseases

ijms-logo“The Endocannabinoid System (ECS) is primarily responsible for maintaining homeostasis, a balance in internal environment (temperature, mood, and immune system) and energy input and output in living, biological systems.

In addition to regulating physiological processes, the ECS directly influences anxiety, feeding behaviour/appetite, emotional behaviour, depression, nervous functions, neurogenesis, neuroprotection, reward, cognition, learning, memory, pain sensation, fertility, pregnancy, and pre-and post-natal development.

The ECS is also involved in several pathophysiological diseases such as cancer, cardiovascular diseases, and neurodegenerative diseases. In recent years, genetic and pharmacological manipulation of the ECS has gained significant interest in medicine, research, and drug discovery and development.

The distribution of the components of the ECS system throughout the body, and the physiological/pathophysiological role of the ECS-signalling pathways in many diseases, all offer promising opportunities for the development of novel cannabinergic, cannabimimetic, and cannabinoid-based therapeutic drugs that genetically or pharmacologically modulate the ECS via inhibition of metabolic pathways and/or agonism or antagonism of the receptors of the ECS. This modulation results in the differential expression/activity of the components of the ECS that may be beneficial in the treatment of a number of diseases.

This manuscript in-depth review will investigate the potential of the ECS in the treatment of various diseases, and to put forth the suggestion that many of these secondary metabolites of Cannabis sativa L. (hereafter referred to as “C. sativa L.” or “medical cannabis”), may also have potential as lead compounds in the development of cannabinoid-based pharmaceuticals for a variety of diseases.”

https://pubmed.ncbi.nlm.nih.gov/34502379/

https://www.mdpi.com/1422-0067/22/17/9472

 

“Cannabis sativa L. as a Natural Drug Meeting the Criteria of a Multitarget Approach to Treatment”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7830475/

Experimental Cannabinoid 2 Receptor Activation by Phyto-Derived and Synthetic Cannabinoid Ligands in LPS-Induced Interstitial Cystitis in Mice.

molecules-logo“Interstitial cystitis (IC) is a chronic bladder disorder with unclear etiology.

The endocannabinoid system has been identified as a key regulator of immune function, with experimental evidence for the involvement of cannabinoid receptors in bladder inflammation.

This study used intravital microscopy (IVM) and behavioral testing in lipopolysaccharide-induced IC, to investigate the anti-inflammatory analgesic effects of a natural dietary sesquiterpenoid, beta-caryophyllene (BCP), which is present in cannabis among other plants, and has reported agonist actions at the cannabinoid 2 receptor (CB2R).

BCP’s anti-inflammatory actions were compared to the synthetic CB2R-selective cannabinoid, HU308, and to an FDA-approved clinical treatment (dimethyl sulfoxide: DMSO). IVM data revealed that intravesical instillation of BCP and/or HU308 significantly reduces the number of adhering leukocytes in submucosal bladder venules and improves bladder capillary perfusion.

The effects of BCP were found to be comparable to that of the selective CB2R synthetic cannabinoid, HU308, and superior to intravesical DMSO treatment. Oral treatment with BCP was also able to reduce bladder inflammation and significantly reduced mechanical allodynia in experimental IC.

Based on our findings, we believe that CB2R activation may represent a viable therapeutic target for IC, and that drugs that activate CB2R, such as the generally regarded as safe (GRAS) dietary sesquiterpenoid, BCP, may serve as an adjunct and/or alternative treatment option for alleviating symptoms of inflammation and pain in the management of IC.”

https://www.ncbi.nlm.nih.gov/pubmed/31766439

https://www.mdpi.com/1420-3049/24/23/4239

“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

“Beta-caryophyllene is a dietary cannabinoid.”   https://www.ncbi.nlm.nih.gov/pubmed/18574142

ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.

Image result for Curr Clin Pharmacol.

“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

Intrathecal cannabinoid-1 receptor agonist prevents referred hyperalgesia in acute acrolein-induced cystitis in rats.

“We investigated the capacity of intrathecal arachidonyl-2′-chloroethylamide (ACEA), a cannabinoid-1 receptor (CB1R) agonist, to inhibit referred hyperalgesia and increased bladder contractility resulting from acute acrolein-induced cystitis in rats…

These findings suggest that pain arising from cystitis may be inhibited by activation of spinal CB1R but the acute local response of the bladder appeared to be unaffected by stimulation of spinal CB1R.”

http://www.ncbi.nlm.nih.gov/pubmed/26069885

The anti-hyperalgesic actions of the cannabinoid anandamide and the putative CB2 receptor agonist palmitoylethanolamide in visceral and somatic inflammatory pain.

“The therapeutic effects of the cannabinoid anandamide and the putative CB2 agonist palmitoylethanolamide were tested in a model of persistent visceral pain (turpentine inflammation of the urinary bladder)…

The results confirm the analgesic potential of endogenous ligands at cannabinoid receptor sites.

The anti-nociceptive effect of the putative CB2 receptor agonist, palmitoylethanolamide, is particularly interesting since it is believed to be a peripherally mediated effect.

This observation might be exploited to separate central psychotropic effects from peripheral analgesic actions of the cannabinoids, under inflammatory conditions.”

http://www.ncbi.nlm.nih.gov/pubmed/9696473

Cannabinoid receptor 2 is increased in acutely and chronically inflamed bladder of rats.

“Cannabinoid receptors are expressed in the urinary bladder and may affect bladder function… CB2 receptors may be a viable target for pharmacological treatment of bladder inflammation and associated pain…

In this study, we have shown that CB1 and CB2 are present in the bladder and its innervation, and that expression of CB2 is increased in the bladders of rats with acute and chronic cystitis. Bladder inflammation and pain is the summation of a number of biological events, including participation of the endocannabinoid system.

The endocannabinoid system could play an important role in modulation of severity of bladder inflammation and pain, and it may be possible to take advantage of the cannabinoid system in the bladder to decrease inflammation and resultant pain.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2592089/

Anandamide-evoked activation of vanilloid receptor 1 contributes to the development of bladder hyperreflexia and nociceptive transmission to spinal dorsal horn neurons in cystitis.

  Figure 4.

“The role of anandamide in the development of inflammatory hyperalgesia and visceral hyperreflexia was studied in the rat urinary bladder…

These results suggest that anandamide, through activating TRPV1, contributes to the development of hyperreflexia and hyperalgesia during cystitis.”

http://www.jneurosci.org/content/24/50/11253.long

Increased cannabinoid receptor 1-immunoreactive nerve fibers in overactive and painful bladder disorders and their correlation with symptoms.

“To study the expression of cannabinoid receptor 1 (CB1) in human urinary bladder hypersensitivity and overactivity disorders, and correlate changes with symptoms. Cannabinoid receptor agonists have been shown to modulate urinary bladder contractility and reduce pain after bladder inflammation; their clinical efficacy on lower urinary tract symptoms was demonstrated in the Cannabinoids in Multiple Sclerosis study…

CONCLUSIONS:

The results of this study suggest that increased nerve fibers, which express CB1, may be related to bladder pain in PBS (painful bladder syndrome) and urgency in IDO (idiopathic detrusor overactivity).

Our findings support clinical trials of CB1 agonists in bladder disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/20346490

Differential expression of functional cannabinoid receptors in human bladder detrusor and urothelium.

“Although cannabinoid receptor expression has been demonstrated in human brain and other peripheral neuronal tissues, definitive expression of these receptors in the human bladder has not been reported. Consequently we investigated the expression of functional cannabinoid 1 and 2 receptors in human bladder detrusor and urothelium…

CONCLUSIONS:

Together these findings suggest a physiological role of cannabinoid 1 and 2 receptors in the human bladder.

Moreover, these results confirm the presence of functional cannabinoid 1 and 2 receptors in the human bladder, which can serve as a target for drugs acting on symptoms of interstitial cystitis/painful bladder syndrome.”

http://www.ncbi.nlm.nih.gov/pubmed/19237176