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

The current state and future perspectives of cannabinoids in cancer biology.

Cancer Medicine

“To date, cannabinoids have been allowed in the palliative medicine due to their analgesic and antiemetic effects, but increasing number of preclinical studies indicates their anticancer properties. Cannabinoids exhibit their action by a modulation of the signaling pathways crucial in the control of cell proliferation and survival. Many in vitro and in vivo experiments have shown that cannabinoids inhibit proliferation of cancer cells, stimulate autophagy and apoptosis, and have also a potential to inhibit angiogenesis and metastasis. In this review, we present an actual state of knowledge regarding molecular mechanisms of cannabinoids’ anticancer action, but we discuss also aspects that are still not fully understood such as the role of the endocannabinoid system in a carcinogenesis, the impact of cannabinoids on the immune system in the context of cancer development, or the cases of a stimulation of cancer cells’ proliferation by cannabinoids. The review includes also a summary of currently ongoing clinical trials evaluating the safety and efficacy of cannabinoids as anticancer agents.”

https://www.ncbi.nlm.nih.gov/pubmed/29473338

http://onlinelibrary.wiley.com/doi/10.1002/cam4.1312/abstract

Exogenous Cannabinoid Efficacy: Merely a Pharmacokinetic Interaction?

Clinical Pharmacokinetics

“Endocannabinoid pharmacology is now relatively well understood with a number of endocannabinoids and endogenous cannabinoid neurotransmitters identified and the pharmacokinetics relatively well ascertained.

Further, the cannabinoid receptors are now molecularly and pharmacologically characterised and the cell processes involved in endocannabinoid transcription, synthesis, post-translational modification and protein expression are reported.

Endogenous cannabinoids have been shown to have key roles in immune and pain pathways and neuro-behavioural signalling including appetite regulation. Significant recent interest has thus been shown in understanding these pathways to guide the development of agents that inhibit the natural catabolism of endogenous cannabinoids to modify pain and appetite, and to synthesise antagonists for the treatment of disease such as obesity.

This research is concurrent with the renewed clinical interest in exogenous cannabinoids and their use in disease. However, the complex pharmacology and physiological effects of exogenous cannabinoids, either as individual components or in combination, as extracts or via administration of the whole plant in humans, are less well known.

Yet as with all other therapeutics, including those derived from plants, knowledge of the pharmacokinetics and dynamics of the complete plant, the individual chemical molecules and their synthetic versions, including formulations and excipients is a standard part of drug development.

This article covers the key pharmacological knowledge required to guide further exploration of the toxicity and efficacy of different cannabinoids and their formulations in blinded placebo-controlled studies.”

https://www.ncbi.nlm.nih.gov/pubmed/28921125

https://link.springer.com/article/10.1007%2Fs40262-017-0599-0

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

Limited Access to a High Fat Diet Alters Endocannabinoid Tone in Female Rats.

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“Emerging evidence suggest an impaired endocannabinoid activity in the pathophysiology of binge eating disorder (BED). Herein, we investigated whether endocannabinoid tone could be modified as a consequence of dietary-induced binge eating in female rats.

For this purpose, brain levels of the endocannabinoids anandamide (AEA) and 2-arachidonoyl glycerol (2-AG), as well as two endocannabinoid-like lipids, oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), were assessed in different brain areas involved in the hedonic feeding (i.e., prefrontal cortex, nucleus accumbens, amygdala, hippocampus, and hypothalamus).

The brain density of cannabinoid type-1 receptors (CB1) was also evaluated. Furthermore, we determined plasma levels of leptin, ghrelin, and corticosterone hormones, which are well-known to control the levels of endocannabioids and/or CB1 receptors in the brain.

To induce binge eating behavior, rats were subject to an intermittent and limited access to a high fat diet (HFD) (margarine). Three experimental groups were used, all with ad libitum access to chow: control (CTRL), with no access to margarine; low restriction (LR), with 2 h margarine access 7 days/week; high restriction (HR), with 2 h margarine access 3 days/week. Bingeing was established when margarine intake in the HR group exceeded that of the LR group.

Our results show that, compared to CTRL, AEA significantly decreased in the caudate putamen, amygdala, and hippocampus of HR group. In contrast, 2-AG significantly increased in the hippocampus while OEA decreased in the hypothalamus. Similar to the HR group, AEA and OEA decreased respectively in the amygdala and hypothalamus and 2-AG increased in the hippocampus of LR group. Moreover, LR group also had AEA decreased in the prefrontal cortex and increased in the nucleus accumbens. In both groups we found the same reduction of CB1 receptor density in the prefrontal cortex compared to CTRL. Also, LR and HR groups showed alterations in both ghrelin and corticosterone levels, while leptin remained unaltered.

In conclusion, our findings show a modified endocannabinoid tone due to margarine exposure, in several brain areas that are known to influence the hedonic aspect of food. Even if not uniquely specific to binge eating, margarine-induced changes in endocannabinoid tone could contributes to the development and maintenance of this behavior.”

https://www.ncbi.nlm.nih.gov/pubmed/29456490

https://www.frontiersin.org/articles/10.3389/fnins.2018.00040/full

Cannabinoids prevent depressive-like symptoms and alterations in BDNF expression in a rat model of PTSD.

 Cover image

“Posttraumatic stress disorder (PTSD) is a debilitating condition highly comorbid with depression. The endocannabinoid (eCB) system and brain-derived neurotrophic factor (BDNF) are suggestively involved in both disorders.

We examined whether cannabinoids can prevent the long-term depressive-like symptoms induced by exposure to the shock and situational reminders (SRs) model of PTSD. The CB1/2 receptor agonist WIN55,212-2 (0.5 mg/kg; i.p.), the fatty acid hydrolase (FAAH) inhibitor URB597 (0.3 mg/kg, i.p.) or vehicle were administered 2 h after severe shock.

Cannabinoids prevented the shock/SRs-induced alterations in social recognition memory, locomotion, passive coping, anxiety-like behavior, anhedonia, fear retrieval, fear extinction and startle response as well as the decrease in BDNF levels in the hippocampus and prefrontal cortex (PFC). Furthermore, significant correlations were found between depressive-like behaviors and BDNF levels in the brain.

The findings suggest that cannabinoids may prevent both depressive- and PTSD-like symptoms following exposure to severe stress and that alterations in BDNF levels in the brains’ fear circuit are involved in these effects.”

https://www.ncbi.nlm.nih.gov/pubmed/29458190

https://www.sciencedirect.com/science/article/pii/S027858461731000X

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/

Plasma N-acylethanolamine and endocannabinoid levels in burning mouth syndrome: potential role in disease pathogenesis.

Journal of Oral Pathology & Medicine

“The objective was to measure endocannabinoid (eCB) ligands and non-cannabinoid N-acylethanolamine (NAE) molecules in plasma from individuals with burning mouth syndrome (BMS), and to determine if plasma eCB/NAE levels correlated with pain, inflammation and depressive symptomatology in this cohort.

RESULTS:

Plasma levels of PEA, but not OEA, AEA or 2-AG, were significantly elevated in patients with BMS, when compared to plasma from healthy individuals. Plasma PEA, OEA and AEA levels correlated with depressive symptomatology.

CONCLUSIONS:

This is the first evidence to indicate that circulating eCB/NAE levels are altered in BMS.”

https://www.ncbi.nlm.nih.gov/pubmed/29436743

http://onlinelibrary.wiley.com/doi/10.1111/jop.12692/abstract

Neuroprotective Effects of MAGL (Monoacylglycerol Lipase) Inhibitors in Experimental Ischemic Stroke.

American Heart Association Learn and Live

“MAGL (monoacylglycerol lipase) is an enzyme that hydrolyzes the endocannabinoid 2-arachidonoylglycerol and regulates the production of arachidonic acid and prostaglandins-substances that mediate tissue inflammatory response. Here, we have studied the effects of the selective MAGL inhibitors JZL184 and MJN110 and their underlying molecular mechanisms on 3 different experimental models of focal cerebral ischemia.

Pharmacological inhibition of MAGL significantly attenuated infarct volume and hemispheric swelling. MAGL inhibition also ameliorated sensorimotor deficits, suppressed inflammatory response, and decreased the number of degenerating neurons. These beneficial effects of MAGL inhibition were not fully abrogated by selective antagonists of cannabinoid receptors, indicating that the anti-inflammatory effects are caused by inhibition of eicosanoid production rather than by activation of cannabinoid receptors.

Our results suggest that MAGL may contribute to the pathophysiology of focal cerebral ischemia and is thus a promising therapeutic target for the treatment of ischemic stroke.”

https://www.ncbi.nlm.nih.gov/pubmed/29440474

http://stroke.ahajournals.org/content/early/2018/02/12/STROKEAHA.117.019664