Cannabinoids in the management of chronic pain: a front line clinical perspective.

“Chronic pain is an escalating public health problem. Currently available treatments are inadequate to control chronic pain conditions, and there is a critical need for novel treatments.

Over a half century of elegant preclinical research has identified the presence of a sophisticated endocannabinoid system that is part of our natural pain and immune defense network.

Convergent work has supported the significant potential to exploit this system to decrease pain and inflammation.

Although the clinical research remains in its infancy, recent systematic reviews have found that 25 of 30 randomized controlled trials have demonstrated a significant analgesic effect.

The authors concluded that cannabinoids currently available for clinical use demonstrate a modest analgesic effect and are safe for the management of chronic pain.

There is a critical need for more translational research so that the excellent work of Dr. Itai Bab and our basic science colleagues around the world can move forward in providing novel cannabinoid-based medicines.

This should include more potent analgesics that are limited in side effects with several routes of delivery. Our patients deserve additional agents for pain control with a novel mechanism of action, and cannabinoids are the new frontier.”

http://www.ncbi.nlm.nih.gov/pubmed/26581068

Seeing over the horizon – targeting the endocannabinoid system for the treatment of ocular disease.

“The observation that marijuana reduces intraocular pressure was made by Hepler and Frank in the 1970s. Since then, there has been a significant body of work investigating cannabinoids for their potential use as therapeutics.

To date, no endocannabinoid system (ECS)-modulating drug has been approved for clinical use in the eye; however, recent advances in our understanding of the ECS, as well as new pharmacological tools, has renewed interest in the development of ocular ECS-based therapeutics.

This review summarizes the current state-of-affairs for the use of ECS-modulating drugs for the treatment of glaucoma and ocular inflammatory and ischemic disease.”

http://www.ncbi.nlm.nih.gov/pubmed/26565550

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

“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

Endocannabinoid regulation of nausea is mediated by 2-arachidonoylglycerol (2-AG) in the rat visceral insular cortex.

“Cannabinoid (CB) agonists suppress nausea in humans and animal models; yet, their underlying neural substrates remain largely unknown.

Evidence suggests that the visceral insular cortex (VIC) plays a critical role in nausea. Given the expression of CB1 receptors and the presence of endocannabinoids in this brain region, we hypothesized that the VIC endocannabinoid system regulates nausea…

Taken together, these findings provide compelling evidence that acute nausea selectively increases 2-AG in the VIC, and suggests that 2-AG signaling within the VIC regulates nausea by reducing neuronal activity in this forebrain region.”

Clinical Significance of Cannabinoid Receptors CB1 and CB2 Expression in Human Malignant and Benign Thyroid Lesions.

“The endocannabinoid system is comprised of cannabinoid receptors (CB1 and CB2), their endogenous ligands (endocannabinoids), and proteins responsible for their metabolism participate in many different functions indispensable to homeostatic regulation in several tissues, exerting also antitumorigenic effects.

The present study aimed to evaluate the clinical significance of CB1 and CB2 expression in human benign and malignant thyroid lesions.

Our data suggest that CB receptors may be involved in malignant thyroid transformation and especially CB2 receptor could serve as useful biomarker and potential therapeutic target in thyroid neoplasia.”

http://www.ncbi.nlm.nih.gov/pubmed/26539529

http://www.hindawi.com/journals/bmri/2015/839403/

Activation of Endocannabinoid System Is Associated with Persistent Inflammation in Human Aortic Aneurysm.

“Human aortic aneurysms have been associated with inflammation and vascular remodeling. Since the endocannabinoid system modulates inflammation and tissue remodeling, we investigated its components in human aortic aneurysms…

Our data provides evidence for endocannabinoid system activation in human aortic aneurysms, associated with persistent low-level inflammation and vascular remodeling.”

http://www.ncbi.nlm.nih.gov/pubmed/26539497

Crosstalk between endocannabinoid and immune systems: a potential dysregulation in depression?

“The endocannabinoid (eCB) system, an endogenous lipid signaling system, appears to be dysregulated in depression. The role of endocannabinoids (eCBs) as potent immunomodulators, together with the accumulating support for a chronic low-grade inflammatory profile in depression, suggests a compelling hypothesis for a fundamental impairment in their intercommunication, in depression.

OBJECTIVE:

We aim to review previous literature on individual associations between the immune and eCB systems and depression. It will focus on peripheral and central mechanisms of crosstalk between the eCB and immune systems. A potential dysregulation in this crosstalk will be discussed in the context of depression.

RESULTS:

Investigations largely report a hypoactivity of the eCB system and increased inflammatory markers in individuals with depression. Findings depict a multifaceted communication whereby immunocompetent and eCB-related cells can both influence the suppression and enhancement of the other’s activity in both the periphery and central nervous system. A dysregulation of the eCB system, as seen in depression, appears to be associated with central and peripheral concentrations of inflammatory agents implicated in the pathophysiology of this illness.

CONCLUSION:

The eCB and immune systems have been individually associated with and implicated in pathogenic mechanisms of depression. Both systems tightly regulate the other’s activity. As such, a dysregulation in this crosstalk has potential to influence the onset and maintenance of this neuropsychiatric illness. However, few studies have investigated both systems and depression conjointly. This review highlights the demand to consider joint eCB-immune interactions in the pathoetiology of depression.”

http://www.ncbi.nlm.nih.gov/pubmed/26483037

Endocannabinoid signaling mediates oxytocin-driven social reward.

Image result for Proc Natl Acad Sci U S A.

“Marijuana exerts profound effects on human social behavior, but the neural substrates underlying such effects are unknown. Here we report that social contact increases, whereas isolation decreases, the mobilization of the endogenous marijuana-like neurotransmitter, anandamide, in the mouse nucleus accumbens (NAc), a brain structure that regulates motivated behavior. The results indicate that anandamide-mediated signaling at CB1 receptors, driven by oxytocin, controls social reward. Deficits in this signaling mechanism may contribute to social impairment in autism spectrum disorders and might offer an avenue to treat these conditions.”  http://www.ncbi.nlm.nih.gov/pubmed/26504214

“In conclusion, our results illuminate a mechanism underlying the prosocial actions of oxytocin, and provide unexpected insights on possible neural substrates involved in the social facilitation caused by marijuana. Pharmacological modulation of oxytocin-driven anandamide signaling (by using, for example, FAAH inhibitors) might open new avenues to treat social impairment in autism spectrum disorders.”  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4653148/

Controlled downregulation of the cannabinoid CB1 receptor provides a promising approach for the treatment of obesity and obesity-derived type 2 diabetes.

“Increased activity of the endocannabinoid system has emerged as a pathogenic factor in visceral obesity, which is a risk factor for type 2 diabetes mellitus (T2DM).

The endocannabinoid system is composed of at least two G-protein-coupled receptors (GPCRs), the cannabinoid receptor type 1 (CB1), and the cannabinoid receptor type 2 (CB2).

Downregulation of CB1 activity in rodents and humans has proven efficacious to reduce food intake, abdominal adiposity, fasting glucose levels, and cardiometabolic risk factors.

Unfortunately, downregulation of CB1 activity by universally active CB1 inverse agonists has been found to elicit psychiatric side effects, which led to the termination of using globally active CB1 inverse agonists to treat diet-induced obesity.

Interestingly, preclinical studies have shown that downregulation of CB1 activity by CB1 neutral antagonists or peripherally restricted CB1 inverse agonists provided similar anorectic effects and metabolic benefits without psychiatric side effects seen in globally active CB1 inverse agonists.

Furthermore, downregulation of CB1 activity may ease endoplasmic reticulum and mitochondrial stress which are contributors to obesity-induced insulin resistance and type 2 diabetes.

This suggests new approaches for cannabinoid-based therapy in the management of obesity and obesity-related metabolic disorders including type 2 diabetes.”

http://www.ncbi.nlm.nih.gov/pubmed/26498013

Peripherally Restricted Cannabinoids for the Treatment of Pain.

“The use of cannabinoids for the treatment of chronic diseases has increased in the United States, with 23 states having legalized the use of marijuana.

Although currently available cannabinoid compounds have shown effectiveness in relieving symptoms associated with numerous diseases, the use of cannabis or cannabinoids is still controversial mostly due to their psychotropic effects (e.g., euphoria, laughter) or central nervous system (CNS)-related undesired effects (e.g., tolerance, dependence).

A potential strategy to use cannabinoids for medical conditions without inducing psychotropic or CNS-related undesired effects is to avoid their actions in the CNS.

This approach could be beneficial for conditions with prominent peripheral pathophysiologic mechanisms (e.g., painful diabetic neuropathy, chemotherapy-induced neuropathy).

In this article, we discuss the scientific evidence to target the peripheral cannabinoid system as an alternative to cannabis use for medical purposes, and we review the available literature to determine the pros and cons of potential strategies that can be used to this end.”

http://www.ncbi.nlm.nih.gov/pubmed/26497478