ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.

Posted on April 19, 2016 by David

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

Cannabinoid CB1 receptors and mTORC1 signalling pathway interact to modulate glucose homeostasis.

Posted on November 14, 2015 by David

“The endocannabinoid system (ECS) is an inter-cellular signalling mechanism that is present in the islets of Langerhans and plays a role in the modulation of insulin secretion and beta-cell mass expansion.

The mammalian target of rapamycin complex 1 (mTORC1) is a key intra-cellular pathway involved in energy homeostasis and known to importantly affect pancreatic islet’s physiology.

These findings suggest a functional interaction between the ECS and the mTORC1 pathway within the endocrine pancreas and at the whole organism level, which could have implications for the development of new therapeutic approaches for pancreatic beta-cell diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/26563389

Emerging role of cannabinoids in gastrointestinal and liver diseases: basic and clinical aspects.

Posted on February 19, 2015 by David

“A multitude of physiological effects and putative pathophysiological roles have been proposed for the endogenous cannabinoid system in the gastrointestinal tract, liver and pancreas.

These range from effects on epithelial growth and regeneration, immune function, motor function, appetite control, fibrogenesis and secretion.

Cannabinoids have the potential for therapeutic application in gut and liver diseases.

Two exciting therapeutic applications in the area of reversing hepatic fibrosis as well as antineoplastic effects may have a significant impact in these diseases.

This review critically appraises the experimental and clinical evidence supporting the clinical application of cannabinoid receptor-based drugs in gastrointestinal, liver and pancreatic diseases.

Application of modern pharmacological principles will most probably expand the selective modulation of the cannabinoid system peripherally in humans.

We anticipate that, in addition to the approval in several countries of the CB(1) antagonist, rimonabant, for the treatment of obesity and associated metabolic dysfunctions, other cannabinoid modulators are likely to have an impact on human disease in the future, including hepatic fibrosis and neoplasia.”

http://www.ncbi.nlm.nih.gov/pubmed/18397936

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

Therapeutic potential of cannabinoid medicines.

Posted on September 6, 2013 by David

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

The endocannabinoid system and its therapeutic exploitation.

Posted on May 24, 2013 by David

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“The term ‘endocannabinoid’ – originally coined in the mid-1990s after the discovery of membrane receptors for the psychoactive principle in Cannabis, Delta9-tetrahydrocannabinol and their endogenous ligands – now indicates a whole signalling system that comprises cannabinoid receptors, endogenous ligands and enzymes for ligand biosynthesis and inactivation. This system seems to be involved in an ever-increasing number of pathological conditions. With novel products already being aimed at the pharmaceutical market little more than a decade since the discovery of cannabinoid receptors, the endocannabinoid system seems to hold even more promise for the future development of therapeutic drugs. We explore the conditions under which the potential of targeting the endocannabinoid system might be realized in the years to come.” http://www.ncbi.nlm.nih.gov/pubmed/15340387

http://www.nature.com/nrd/journal/v3/n9/full/nrd1495.html

Cannabinoid derivatives induce cell death in pancreatic MIA PaCa-2 cells via a receptor-independent mechanism.

Posted on January 21, 2013 by David

“Cannabinoids (CBs) are implicated in the control of cell survival in different types of tumors, but little is known about the role of CB system in pancreatic cancer. Herein, we investigated the in vitro antitumor activity of CBs and the potential role of their receptors in human pancreatic cancer cells MIA PaCa-2…

These findings exclude the involvement of CB receptors in the regulation of MIA PaCa-2 cell growth and put AM251 forward as a candidate for the development of novel compounds worthy to be tested in this type of neoplasia.”

http://www.ncbi.nlm.nih.gov/pubmed/16500647

The role of the pancreatic endocannabinoid system in glucose metabolism.

Posted on January 21, 2013 by David

“The endogenous cannabinoid system participates in the regulation of energy homeostasis, and this fact led to the identification of a new group of therapeutic agents for complicated obesity and diabetes. Cannabinoid receptor antagonists are now realities in clinical practice. The use of such antagonists for reducing body weight gain, lowering cholesterol and improving glucose homeostasis is based on the ability of the endocannabinoids to coordinately regulate energy homeostasis by interacting with central and peripheral targets, including adipose tissue, muscle, liver and endocrine pancreas. In this review we will analyse the presence of this system in the main cell types of the islets of Langerhans, as well as the physiological relevance of the endocannabinoids and parent acylethanolamides in hormone secretion and glucose homeostasis. We will also analyse the impact that these findings may have in clinical practice and the potential outcome of new therapeutic strategies for modulating glucose homeostasis and insulin/glucagon secretion.”

http://www.ncbi.nlm.nih.gov/pubmed/19285263

Presence of functional cannabinoid receptors in human endocrine pancreas.

Posted on January 21, 2013 by David

“We examined the presence of functional cannabinoid receptors 1 and 2 (CB1, CB2) in isolated human islets, phenotyped the cells producing cannabinoid receptors and analysed the actions of selective cannabinoid receptor agonists on insulin, glucagon and somatostatin secretion in vitro. We also described the localisation on islet cells of: (1) the endocannabinoid-producing enzymes N-acyl-phosphatidyl ethanolamine-hydrolysing phospholipase D and diacylglycerol lipase; and (2) the endocannabinoid-degrading enzymes fatty acid amidohydrolase and monoacyl glycerol lipase.

RESULTS:

Human islets of Langerhans expressed CB1 and CB2 (also known as CNR1 and CNR2) mRNA and CB1 and CB2 proteins, and also the machinery involved in synthesis and degradation of 2-AG (the most abundant endocannabinoid, levels of which were modulated by glucose). Immunofluorescence revealed that CB1 was densely located in glucagon-secreting alpha cells and less so in insulin-secreting beta cells. CB2 was densely present in somatostatin-secreting delta cells, but absent in alpha and beta cells. In vitro experiments revealed that CB1 stimulation enhanced insulin and glucagon secretion, while CB2 agonism lowered glucose-dependent insulin secretion, showing these cannabinoid receptors to be functional.

CONCLUSIONS/INTERPRETATION:

Together, these results suggest a role for endogenous endocannabinoid signalling in regulation of endocrine secretion in the human pancreas.”

http://www.ncbi.nlm.nih.gov/pubmed/18092149

Regulation, function, and dysregulation of endocannabinoids in models of adipose and beta-pancreatic cells and in obesity and hyperglycemia.

Posted on January 21, 2013 by David

“Cannabinoid CB(1) receptor blockade decreases weight and hyperinsulinemia in obese animals and humans in a way greatly independent from food intake.

The objective of this study was to investigate the regulation and function of the endocannabinoid system in adipocytes and pancreatic beta-cells.

Endocannabinoid enzyme and adipocyte protein expression, and endocannabinoid and insulin levels were measured.

RESULTS:

Endocannabinoids are present in adipocytes with levels peaking before differentiation, and in RIN-m5F beta-cells, where they are under the negative control of insulin. Chronic treatment of adipocytes with insulin is accompanied by permanently elevated endocannabinoid signaling, whereas culturing of RIN-m5F beta-cells in high glucose transforms insulin down-regulation of endocannabinoid levels into up-regulation. Epididymal fat and pancreas from mice with diet-induced obesity contain higher endocannabinoid levels than lean mice. Patients with obesity or hyperglycemia caused by type 2 diabetes exhibit higher concentrations of endocannabinoids in visceral fat or serum, respectively, than the corresponding controls. CB(1) receptor stimulation increases lipid droplets and decreases adiponectin expression in adipocytes, and it increases intracellular calcium and insulin release in RIN-m5F beta-cells kept in high glucose.

CONCLUSIONS:

Peripheral endocannabinoid overactivity might explain why CB(1) blockers cause weight-loss independent reduction of lipogenesis, of hypoadiponectinemia, and of hyperinsulinemia in obese animals and humans.”

http://jcem.endojournals.org/content/91/8/3171.long

Mechanisms for the coupling of cannabinoid receptors to intracellular calcium mobilization in rat insulinoma beta-cells.

Posted on January 21, 2013 by David

“In RIN m5F rat insulinoma beta-cells, agonists at cannabinoid CB(1) receptors modulate insulin release. Here we investigated in these cells the effect of the activation of cannabinoid CB(1) and CB(2) receptors on intracellular Ca(2+) ([Ca(2+)](i)). The CB(1) agonist arachidonoyl-chloro-ethanolamide (ACEA), and the CB(2) agonist JWH133, elevated [Ca(2+)](i) in a way sensitive to the inhibitor of phosphoinositide-specific phospholipase C (PI-PLC), U73122 (but not to pertussis toxin and forskolin), and independently from extracellular Ca(2+). PI-PLC-dependent Ca(2+) mobilization by ACEA was entirely accounted for by activation of inositol-1,3,4-phosphate (IP(3)) receptors on the endoplasmic reticulum (ER), whereas the effect of JWH133 was not sensitive to all tested inhibitors of IP(3) and ryanodine receptors. ACEA, but not JWH133, significantly inhibited the effect on [Ca(2+)](i) of bombesin, which acts via G(q/11)- and PI-PLC-coupled receptors in insulinoma cells. The endogenous CB(1) agonists, anandamide and N-arachidonoyldopamine, which also activate transient receptor potential vanilloid type 1 (TRPV1) receptors expressed in RIN m5F cells, elevated [Ca(2+)](i) in the presence of extracellular Ca(2+) in a way sensitive to both CB(1) and TRPV1 antagonists. These results suggest that, in RIN m5F cells, CB(1) receptors are coupled to PI-PLC-mediated mobilization of [Ca(2+)](i) and might inhibit bombesin signaling.”

http://www.ncbi.nlm.nih.gov/pubmed/17585904