Role of the endocannabinoid system in drug addiction.

Biochemical Pharmacology

“Drug addiction is a chronic relapsing disorder that produces a dramaticglobal health burden worldwide. Not effective treatment of drug addiction is currently available probably due to the difficulties to find an appropriate target to manage this complex disease raising the needs for further identification of novel therapeutic approaches.

The endocannabinoid system has been found to play a crucial role in the neurobiological substrate underlying drug addiction.

Endocannabinoids and cannabinoid receptors are widely expressed in the main areas of the mesocorticolimbic system that participate in the initiation and maintenance of drug consumption and in the development of compulsion and loss of behavioral control occurring during drug addiction.

The identification of the important role played by CB1 cannabinoid receptors in drug addiction encouraged the possible used of an early commercialized CB1 receptor antagonist for treating drug addiction.

However, the incidence of serious psychiatric adverse events leaded to the sudden withdrawal from the market of this CB1 antagonist and all the research programs developed by pharmaceutical companies to obtain new CB1 antagonists were stopped.

Currently, new research strategies are under development to target the endocannabinoid system for drug addiction avoiding these side effects, which include allosteric negative modulators of CB1 receptors and compounds targeting CB2 receptors.

Recent studies showing the potential role of CB2 receptors in the addictive properties of different drugs of abuse have open a promising research opportunity to develop novel possible therapeutic approaches.”

https://www.ncbi.nlm.nih.gov/pubmed/30217570

https://www.sciencedirect.com/science/article/abs/pii/S0006295218303952

Cannabinoid 1 Receptor Signaling on Hippocampal GABAergic Neurons Influences Microglial Activity.

Image result for frontiers in molecular neuroscience

“Microglia, the resident immune cells of the brain, play important roles in defending the brain against pathogens and supporting neuronal circuit plasticity. Chronic or excessive pro-inflammatory responses of microglia damage neurons, therefore their activity is tightly regulated.

Pharmacological and genetic studies revealed that cannabinoid type 1 (CB1) receptor activity influences microglial activity, although microglial CB1 receptor expression is very low and activity-dependent. The CB1 receptor is mainly expressed on neurons in the central nervous system (CNS)-with an especially high level on GABAergic interneurons.

Here, we determined whether CB1 signaling on this neuronal cell type plays a role in regulating microglial activity.

Our result suggests that CB1 receptor agonists can modulate microglial activity indirectly, through CB1 receptors on GABAergic neurons.

Altogether, we demonstrated that GABAergic neurons, despite their relatively low density in the hippocampus, have a specific role in the regulation of microglial activity and cannabinoid signaling plays an important role in this arrangement.”

https://www.ncbi.nlm.nih.gov/pubmed/30210289

https://www.frontiersin.org/articles/10.3389/fnmol.2018.00295/full

Cannabis sativa: A comprehensive ethnopharmacological review of a medicinal plant with a long history.

Journal of Ethnopharmacology

“Cannabis sativa L. (C. sativa) is an annual dioecious plant, which shares its origins with the inception of the first agricultural human societies in Asia. Over the course of time different parts of the plant have been utilized for therapeutic and recreational purposes, for instance, extraction of healing oils from seed, or the use of inflorescences for their psychoactive effects. The key psychoactive constituent in C. sativa is called Δ-9-tetrahydrocannabinol (D9-THC). The endocannabinoid system seems to be phylogenetically ancient, as it was present in the most primitive vertebrates with a neuronal network. N-arachidonoylethanolamine (AEA) and 2-arachidonoyl glycerol (2-AG) are the main endocannabinoids ligands present in the animal kingdom, and the main endocannabinoid receptors are cannabinoid type-1 (CB1) receptor and cannabinoid type-2 (CB2) receptor.

AIM OF THE STUDY:

The review aims to provide a critical and comprehensive evaluation, from the ancient times to our days, of the ethnological, botanical, chemical and pharmacological aspects of C. sativa, with a vision for promoting further pharmaceutical research to explore its complete potential as a therapeutic agent.

RESULTS AND CONCLUSIONS:

A detailed comparative analysis of the available resources for C. sativa confirmed its origin and traditional spiritual, household and therapeutic uses and most importantly its popularity as a recreational drug. The result of several studies suggested a deeper involvement of phytocannabinoids (the key compounds in C. sativa) in several others central and peripheral pathophysiological mechanisms such as food intake, inflammation, pain, colitis, sleep disorders, neurological and psychiatric illness. However, despite their numerous medicinal benefits, they are still considered as a menace to the society and banned throughout the world, except for few countries. We believe that this review will help lay the foundation for promoting exhaustive pharmacological and pharmaceutical studies in order to better understand the clinical relevance and applications of non-psychoactive cannabinoids in the prevention and treatment of life-threatening diseases and help to improve the legal status of C. sativa.”

https://www.ncbi.nlm.nih.gov/pubmed/30205181

https://www.sciencedirect.com/science/article/pii/S0378874118316611?via%3Dihub

Cellular localization and regulation of receptors and enzymes of the endocannabinoid system in intestinal and systemic inflammation.

“Surveys suggest that Cannabis provides benefit for people with inflammatory bowel disease.

However, mechanisms underlying beneficial effects are not clear. We performed in situ hybridization RNAscope® combined with immunohistochemistry to show cell-specific distribution and regulation of cannabinoid receptor 1 and 2 (CB1, CB2), G protein-coupled receptor 55 (GPR55), and monoacylglycerol lipase (MGL) mRNA in immune cells using murine models of intestinal and systemic inflammation.

In summary, our study reveals changes in gene expression of members of the endocannabinoid system in situ attesting particularly GPR55 and MGL a distinct cellular role in the regulation of the immune response to intestinal and systemic inflammation.”

https://www.ncbi.nlm.nih.gov/pubmed/30196316

https://link.springer.com/article/10.1007%2Fs00418-018-1719-0

The Endocannabinoid/Cannabinoid Receptor 2 System Protects Against Cisplatin-Induced Hearing Loss.

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“Previous studies have demonstrated the presence of cannabinoid 2 receptor (CB2R) in the rat cochlea which was induced by cisplatin. In an organ of Corti-derived cell culture model, it was also shown that an agonist of the CB2R protected these cells against cisplatin-induced apoptosis.

In the current study, we determined the distribution of CB2R in the mouse and rat cochleae and examined whether these receptors provide protection against cisplatin-induced hearing loss.

These data unmask a protective role of the cochlear endocannabinoid/CB2R system which appears tonically active under normal conditions to preserve normal hearing. However, an exogenous agonist is needed to boost the activity of endocannabinoid/CB2R system for protection against a more traumatic cochlear insult, as observed with cisplatin administration.”

https://www.ncbi.nlm.nih.gov/pubmed/30186120

https://www.frontiersin.org/articles/10.3389/fncel.2018.00271/full

Δ9-tetrahydrocannabivarin impairs epithelial calcium transport through inhibition of TRPV5 and TRPV6.

 Pharmacological Research

“Compounds extracted from the cannabis plant, including the psychoactive Δ9-tetrahydrocannabinol (THC) and related phytocannabinoids, evoke multiple diverse biological actions as ligands of the G protein-coupled cannabinoid receptors CB1 and CB2. In addition, there is increasing evidence that phytocannabinoids also have non-CB targets, including several ion channels of the transient receptor potential superfamily.

We investigated the effects of six non-THC phytocannabinoids on the epithelial calcium channels TRPV5 and TRPV6, and found that one of them, Δ9-tetrahydrocannabivarin (THCV), exerted a strong and concentration-dependent inhibitory effect on mammalian TRPV5 and TRPV6 and on the single zebrafish orthologue drTRPV5/6. Moreover, THCV attenuated the drTRPV5/6-dependent ossification in zebrafish embryos in vivo. Oppositely, 11-hydroxy-THCV (THCV-OH), a product of THCV metabolism in mammals, stimulated drTRPV5/6-mediated Ca2+ uptake and ossification.

These results identify the epithelial calcium channels TRPV5 and TRPV6 as novel targets of phytocannabinoids, and suggest that THCV-containing products may modulate TRPV5- and TRPV6-dependent epithelial calcium transport.”

https://www.ncbi.nlm.nih.gov/pubmed/30170189

https://linkinghub.elsevier.com/retrieve/pii/S1043661818311095

A Brief Background on Cannabis: From Plant to Medical Indications.

 Ingenta Connect

“Cannabis has been used as a medicinal plant for thousands of years.

As a result of centuries of breeding and selection, there are now over 700 varieties of cannabis that contain hundreds of compounds, including cannabinoids and terpenes.

Cannabinoids are fatty compounds that are the main biological active constituents of cannabis. Terpenes are volatile compounds that occur in many plants and have distinct odors.

Cannabinoids exert their effect on the body by binding to receptors, specifically cannabinoid receptors types 1 and 2. These receptors, together with endogenous cannabinoids and the systems for synthesis, transport, and degradation, are called the Endocannabinoid System.

The two most prevalent and commonly known cannabinoids in the cannabis plant are delta-9-tetrahydrocannabinol (THC) and cannabidiol.

The speed, strength, and type of effects of cannabis vary based on the route of administration. THC is rapidly distributed through the body to fatty tissues like the brain and is metabolized by the cytochrome P450 system to 11-hydroxy-THC, which is also psychoactive.

Cannabis and cannabinoids have been indicated for several medical conditions.

There is evidence of efficacy in the symptomatic treatment of nausea and vomiting, pain, insomnia, post-traumatic stress disorder, anxiety, loss of appetite, Tourette’s syndrome, and epilepsy. Cannabis has also been associated with treatment for glaucoma, Huntington’s Disease, Parkinson’s Disease, and dystonia, but there is not good evidence to support its efficacy. Side effects of cannabis include psychosis and anxiety, which can be severe.

Here, we provided a summary of the history of cannabis, its pharmacology, and its medical uses.”

https://www.ncbi.nlm.nih.gov/pubmed/30139415

Cannabinoids and reduced risk of hepatic steatosis in HIV-HCV co-infection: paving the way for future clinical research

Publication Cover

“Whether or not cannabis itself or cannabinoids contained in it may help to reduce hepatic steatosis in HIV-HCV coinfected patients remains an open question. The existing body of knowledge on the interactions between cannabis and the liver suggest a protective effect of cannabinoids on insulin resistance, diabetes, and NAFLD in the general population. Clinical research with randomized study designs is needed to evaluate the efficacy and safety of cannabis-based pharmacotherapies in HIV-HCV coinfected patients. Targeting the endocannabinoid system seems essential to differently manage several pathological conditions such as intestinal inflammation, obesity, diabetes and fatty liver disease. However, to date, few drugs have been tested in clinical trials. CB1-antagonists and CB2 agonists appear to be viable therapeutic options that need to be explored for the management of liver diseases. As HCV cure rates are coming close to 100% in the era of direct-acting antivirals, it is especially important to be able to identify modifiable risk factors of complications and death in HIV-HCV coinfected patients, as well as possible levers for intervention. Given the persistence of metabolic risk factors after HCV eradication, cannabis-based therapies need to be evaluated both as preventive and therapeutic tools in patients living with or at risk of liver steatosis, possibly in combination with existing conventional approaches.”

https://www.tandfonline.com/doi/full/10.1080/14787210.2018.1473764

VCE-004.3, A CANNABIDIOL AMINOQUINONE DERIVATIVE, PREVENTS BLEOMYCIN-INDUCED SKIN FIBROSIS AND INFLAMMATION TROUGH PPARγ- AND CB2 -DEPENDENT PATHWAYS.

Publication cover image

“The endocannabinoid system (ECS) as well as PPARγ are relevant targets for the development of novel compounds against fibrotic diseases such as Systemic Sclerosis (SSc), also called Scleroderma.

The aim of this study was to characterize VCE-004.3, a novel cannabidiol derivative, and to study it anti-inflammatory and anti-fibrotic activities.

CONCLUSION AND IMPLICATIONS:

VCE-004.3 is a novel semi-synthetic cannabidiol derivative behaving as a dual PPARγ/CB2 agonist and CB1 receptor modulator that could be considered for the development of novel therapies against different forms of Scleroderma.”

https://www.ncbi.nlm.nih.gov/pubmed/30033591

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14450

Endocannabinoid system, Stress and HPA axis.

European Journal of Pharmacology

“The endocannabinoid system (ECS), which is composed of the cannabinoid receptors types 1 and 2 (CB1 and CB2) for marijuana’s psychoactive ingredient ∆9-tetrahydrocannabinol (∆9-THC), the endogenous ligands (AEA and 2-AG) and the enzymatic systems involved in their biosynthesis and degradation, recently emerged as important modulator of emotional and non-emotional behaviors. In addition to its recreational actions, some of the earliest reports regarding the effects of Cannabis use on humans were related to endocrine system changes. Accordingly, the ∆9-THC and later on, the ECS signaling have long been known to regulate the hypothalamic-pituitary-adrenocortical (HPA) axis, which is the major neuroendocrine stress response system of mammals. However, how the ECS could modify the stress hormone secretion is not fully understood. Thus, the present article reviews current available knowledge on the role of the ECS signaling as important mediator of interaction between HPA axis activity and stressful conditions, which, in turn could be involved in the development of psychiatric disorders.”

https://www.ncbi.nlm.nih.gov/pubmed/30036537

https://www.sciencedirect.com/science/article/pii/S0014299918304138?via%3Dihub