Cannabinoid Receptors, Mental Pain and Suicidal Behavior: a Systematic Review.

Current Psychiatry Reports

“The current serotonin-based biological model of suicidal behavior (SB) may be too simplistic. There is emerging evidence that other biomarkers and biological systems may be involved in SB pathophysiology. The literature on the endocannabinoid (EC) systems and SB is limited. The objective of the present article is to review all available information on the relationship between cannabinoid receptors (CB1 and CB2 receptors), and SB and/or psychological pain.

RECENT FINDINGS:

Our review is limited by the small number and heterogeneity of studies identified: (1) an autopsy study describing elevated levels of CB1 receptor activity in the prefrontal cortex and suicide in both depression and alcoholism and (2) studies supporting the involvement of both CB1 and CB2 receptors in the regulation of neuropathic pain and stress-induced analgesia. We conclude that cannabinoid receptors, particularly CB1 receptors, may become promising targets for the development of novel therapeutic tools for the treatment of SB.”

https://www.ncbi.nlm.nih.gov/pubmed/29546501

https://link.springer.com/article/10.1007%2Fs11920-018-0880-4

Cannabinoid Receptors and the Endocannabinoid System: Signaling and Function in the Central Nervous System.

ijms-logo

“The biological effects of cannabinoids, the major constituents of the ancient medicinal plant Cannabis sativa (marijuana) are mediated by two members of the G-protein coupled receptor family, cannabinoid receptors 1 (CB1R) and 2. The CB1R is the prominent subtype in the central nervous system (CNS) and has drawn great attention as a potential therapeutic avenue in several pathological conditions, including neuropsychological disorders and neurodegenerative diseases. Furthermore, cannabinoids also modulate signal transduction pathways and exert profound effects at peripheral sites. Although cannabinoids have therapeutic potential, their psychoactive effects have largely limited their use in clinical practice. In this review, we briefly summarized our knowledge of cannabinoids and the endocannabinoid system, focusing on the CB1R and the CNS, with emphasis on recent breakthroughs in the field. We aim to define several potential roles of cannabinoid receptors in the modulation of signaling pathways and in association with several pathophysiological conditions. We believe that the therapeutic significance of cannabinoids is masked by the adverse effects and here alternative strategies are discussed to take therapeutic advantage of cannabinoids.”

https://www.ncbi.nlm.nih.gov/pubmed/29533978

http://www.mdpi.com/1422-0067/19/3/833

Chronic treatment with URB597 ameliorates post-stress symptoms in a rat model of PTSD.

Cover image volume 28, Issue 3

“Activating the endocannabinoid system has become a major focus in the search for novel therapeutics for anxiety and deficits in fear extinction, two defining features of PTSD. We examined whether chronic treatment with the fatty acid amide hydrolase (FAAH) inhibitor URB597 (0.2, 0.3, 0.4 mg/kg, i.p.) or the CB1/2 receptor agonist WIN55,212-2 (0.25, 0.5 mg/kg, i.p.) injected for 3 weeks to rats exposed to the shock and reminders model of PTSD would attenuate post-stress symptoms and affect basolateral amygdala (BLA) and CA1 CB1 receptors.

Exposure to shock and reminders enhanced acoustic startle response and impaired extinction. Rats exposed to shock and reminders and chronically treated with URB597 demonstrated normalized startle response and intact extinction kinetics. WIN55,212-2 only affected the startle response. The therapeutic effects of URB597 and WIN55,212-2 were found to be CB1 receptor dependent, as these effects were blocked when a low dose of the CB1 receptor antagonist AM251 (0.3 mg/kg, i.p. for 3 weeks) was co-administered. Moreover, URB597, but not WIN55,212-2, normalized the shock/reminders-induced upregulation in CB1 receptor levels in the BLA and CA1. One hour after the shock, N-arachidonoylethanolamine (AEA) was increased in the BLA and decreased in the CA1. Circulating 2-arachidonoylglycerol (2-AG) concentrations were decreased in shocked rats, with no significant effect in the BLA or CA1. FAAH activity was increased in the CA1 of shocked rats.

Chronic cannabinoid treatment with URB597 can ameliorate PTSD-like symptoms suggesting FAAH inhibitors as a potentially effective therapeutic strategy for the treatment of disorders associated with inefficient fear coping.”

https://www.ncbi.nlm.nih.gov/pubmed/29519609

http://www.europeanneuropsychopharmacology.com/article/S0924-977X(18)30045-2/fulltext

Extraction Method and Analysis of Cannabinoids in Cannabis Olive Oil Preparations.

“Recently, an increasing number of pharmacists had to supply medicinal products based on Cannabis sativa L. (Cannabaceae), prescribed by physicians to individual patients. 

Cannabis olive oil preparation is the first choice as a concentrated extract of cannabinoids, even though standardized operative conditions for obtaining it are still not available.

In this work, the impact of temperature and extraction time on the concentration of active principles was studied to harmonize the different compounding methods, optimize the extraction process, and reduce the variability among preparations.

https://www.ncbi.nlm.nih.gov/pubmed/29202510

https://www.thieme-connect.de/DOI/DOI?10.1055/s-0043-123074

“Therapeutic Use of Δ9-THC and Cannabidiol: Evaluation of a New Extraction Procedure for the Preparation of Cannabis-based Olive Oil.”  https://www.ncbi.nlm.nih.gov/pubmed/29189144

Absence of cannabinoid 1 receptor in beta cells protects against high-fat/high-sugar diet-induced beta cell dysfunction and inflammation in murine islets.

Diabetologia

“The cannabinoid 1 receptor (CB1R) regulates insulin sensitivity and glucose metabolism in peripheral tissues. CB1R is expressed on pancreatic beta cells and is coupled to the G protein Gαi, suggesting a negative regulation of endogenous signalling in the beta cell.

To assess the direct contribution of beta cell CB1R to metabolism, we designed a mouse model that allows us to determine the role of CB1R specifically in beta cells in the context of whole-body metabolism.

CONCLUSIONS/INTERPRETATION:

Our data demonstrate CB1R to be a negative regulator of beta cell function and a mediator of islet inflammation under conditions of metabolic stress. Our findings point to beta cell CB1R as a therapeutic target, and broaden its potential to include anti-inflammatory effects in both major forms of diabetes.”

https://www.ncbi.nlm.nih.gov/pubmed/29497784

https://link.springer.com/article/10.1007%2Fs00125-018-4576-4

Toxicity, Cannabinoids.

Cover of StatPearls

“Cannabinoids are a collective group of compounds that act on cannabinoid receptors. They include plant-derived phytocannabinoids, synthetic cannabinoids, and endogenously-derived endocannabinoids. The primary source of cannabinoid toxicity is from plant-derived cannabinoids and synthetic cannabinoids. These agents act as cannabinoid receptor agonists. More than 60 naturally occurring cannabinoids are found in the Sativa and Indica species of Cannabis, with delta-9 tetrahydrocannabinol (THC) being the main psychoactive compound. Other naturally occurring cannabinoids include cannabidiol and cannabinol. Marijuana is the most common colloquial name for crushed, dried leaves and flowers of the Cannabis plant. In recent years, there have been many reports of marijuana toxicity, primarily in the pediatric population, as medical and recreational marijuana has been legalized. The terms phytocannabinoids, marijuana and cannabis are used interchangeably. Synthetic cannabinoids were created for therapeutic and research purposes; however, despite legal efforts to limit their availability, synthetic cannabinoids have become an increasingly common drug of abuse, sold under various street names such as K2, Spice, and Black Mamba. Synthetic cannabinoids are associated with much more morbidity and mortality than the phytocannabinoids. Prescription preparations for medical usage include dronabinol, or pure THC, nabilone, a synthetic cannabinoid, and cannabidiol (CBD). Pharmaceutical use of cannabinoids is an ongoing field of research.”

https://www.ncbi.nlm.nih.gov/pubmed/29489164

https://www.ncbi.nlm.nih.gov/books/NBK482175/

Innovative Therapeutic Potential of Cannabinoid Receptors as Targets in Alzheimer’s disease and Less Well-Known Diseases.

“The discovery of cannabinoid receptors at the beginning of the 1990s, CB1 being cloned in 1990 and CB2 cloned in 1993, and the availability of selective and potent cannabimimetics could only be justified by the existence of endogenous ligands that are capable of binding to them. Thus, the characterisation and cloning of the first cannabinoid receptor (CB1) led to the isolation and characterisation of the first endocannabinoid, arachidonoylethanolamide (AEA), two years later and the subsequent identification of a family of lipid transmitters known as the fatty acid ester 2-arachidonoylglycerol (2-AG). The endogenous cannabinoid system is a complex signalling system that comprises transmembrane endocannabinoid receptors, their endogenous ligands (the endocannabinoids), the specific uptake mechanisms and the enzymatic systems related to their biosynthesis and degradation. The endocannabinoid system has been implicated in a wide diversity of biological processes, in both the central and peripheral nervous systems, including memory, learning, neuronal development, stress and emotions, food intake, energy regulation, peripheral metabolism, and the regulation of hormonal balance through the endocrine system. In this context, this article will review the current knowledge of the therapeutic potential of cannabinoid receptor as a target in Alzheimer’s disease and other less well-known diseases that include, among others, multiple sclerosis, bone metabolism, and Fragile X syndrome. The therapeutic applications will be addressed through the study of cannabinoid agonists acting as single drugs and multi-target drugs highlighting the CB2 receptor agonist.”

https://www.ncbi.nlm.nih.gov/pubmed/29484980

http://www.eurekaselect.com/160083/article

Impact of co-administration of oxycodone and smoked cannabis on analgesia and abuse liability.

Image result for neuropsychopharmacology

“Cannabinoids combined with opioids produce synergistic antinociceptive effects, decreasing the lowest effective antinociceptive opioid dose (i.e., opioid-sparing effects) in laboratory animals.

Although pain patients report greater analgesia when cannabis is used with opioids, no placebo-controlled studies have assessed the direct effects of opioids combined with cannabis in humans or the impact of the combination on abuse liability.

This double-blind, placebo-controlled, within-subject study determined if cannabis enhances the analgesic effects of low dose oxycodone using a validated experimental model of pain and its effects on abuse liability.

Cannabis enhances the analgesic effects of sub-threshold oxycodone, suggesting synergy, without increases in cannabis’s abuse liability. These findings support future research into the therapeutic use of opioid-cannabinoid combinations for pain.”

The Role of Cannabinoid Receptor 1 in the Immunopathology of Respiratory Syncytial Virus.

Mary Ann Liebert, Inc. publishers

“Endocannabinoid system plays an important role in pathophysiologic processes such as immune functions and impacts on disease severity.

Our previous study showed that cannabinoid receptor 2 (CB2) affects clinical course of respiratory syncytial virus (RSV) infection. In this study, we investigated the role of cannabinoid receptor 1 (CB1) in RSV immunopathology and its therapeutic potential in mice model.

This study and our previous finding indicated that endocannabinoid signaling regulates the inflammatory response to RSV infection, and is a potential therapeutic candidate for alleviation of RSV-associated immunopathology.”

https://www.ncbi.nlm.nih.gov/pubmed/29461930

http://online.liebertpub.com/doi/10.1089/vim.2017.0098

Role of the Endocannabinoid System in the Neurobiology of Suicide

Cover of The Neurobiological Basis of Suicide

“In the past decade, remarkable advances have been made in cannabinoid (CB) research. The brain endocannabinoid (eCB) system modulates several neurobiological processes and its dysfunction is suggested to be involved in the pathophysiology of mood and drug use disorders.

The CB1 receptor–mediated signaling, in particular, has been shown to play a critical role in the neural circuitry that mediates mood, motivation, and emotional behaviors. This chapter presents the data pertaining to the involvement of the eCB system in depression, suicide, and alcohol addiction.

It appears that the eCB system might have a critical role in the regulation of mood and emotional responses that are impaired in patients with depression and suicidal behavior.

The data provided in this chapter support the notion that the eCB system might be an additional target for the development of a drug against alcohol use, depression, and suicidal behavior.

Among therapeutic agents, antidepressants are the most widely used drugs for the treatment of depression-related disorders.”

https://www.ncbi.nlm.nih.gov/pubmed/23035286

https://www.ncbi.nlm.nih.gov/books/NBK107200/

“Antidepressant-like effect of Δ9-tetrahydrocannabinol and other cannabinoids isolated from cannabis sativa L. The antidepressant action of cannabis as well as the interaction between antidepressants and the endocannabinoid system has been reported. Results of this study show that Δ9-THC and other cannabinoids exert anti-depressant-like actions, and thus may contribute to the overall mood-elevating properties of cannabis.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2866040/