[Progress in study on endocannabinoids and cannabinoid receptors in the treatment for neuropathic pain].

 

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“Endocannabinoids and cannabinoid receptors are expressed in various central pain modulation regions. They maintain in dynamic changes in the expression level and distribution under different pathological and physiological conditions. These changes possess advantage as well as disadvantage. Exogenous administration of endocannabinoids exerts analgesic effect in different pain models, which is mainly mediated by the cannabinoid CB1 and CB2 receptors. Inhibition of enzymes for degrading endocannabinoids in different pain models also shows analgesic effect due to the increased local levels of endocannabinoids.”

Selective modulator of cannabinoid receptor type 2 reduces memory impairment and infarct size during cerebral hypoperfusion and vascular dementia.

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“Vascular dementia is the highly devastating neurodegenerative disorder after Alzheimer’s disease (AD) and mainly found in aged people but the effectual therapeutic target is still not there.

Chronic cerebral hypoperfusion (CCH) has been broadly found in vascular dementia (VaD) patients. CCH is thought to link with neurodegenerative disorders and their subsequent cognitive deteriorate on.

This study has been framed to examine the role of a selective agonist of cannabinoid receptor type 2(CB2); 1-phenylisatin in CCH induced VaD.

These results indicate that 2VO induced CCH in rats, which was attenuated with the treatment of 1-phenylisatin.

Hence, it may be suggested that modulation of cannabinoid receptor may provide benefits in CCH as cognitive impairment and VaD.

Therefore, selective agonists of CB2 receptors may be a potential research target for the alleviation of VaD.”

http://www.ncbi.nlm.nih.gov/pubmed/27586843

The Influence of the CB1 Receptor Ligands on the Schizophrenia-Like Effects in Mice Induced by MK-801.

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“A growing body of psychiatric research has emerged, focusing on the role of endocannabinoid system in psychiatric disorders.

For example, the endocannabinoid system, via cannabinoid CB (CB1 and CB2) receptors, is able to control the function of many receptors, such as N-methyl-D-aspartate (NMDA) receptors connected strictly with psychosis or other schizophrenia-associated symptoms.

The aim of the present research was to investigate the impact of the CB1 receptor ligands on the symptoms typical for schizophrenia.

The present findings confirm that endocannabinoid system is able to modify a variety of schizophrenia-like responses, including the cognitive disturbances and hyperlocomotion in mice.

Antipsychotic-like effects induced by CB1 receptor antagonist, obtained in our research, confirm the potential effect of CB1 receptor blockade and could have important therapeutic implications on clinical settings, in the future.”

http://www.ncbi.nlm.nih.gov/pubmed/27577742

Activation of type 1 cannabinoid receptor (CB1R) promotes neurogenesis in murine subventricular zone cell cultures.

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“The endocannabinoid system has been implicated in the modulation of adult neurogenesis.

Here, we describe the effect of type 1 cannabinoid receptor (CB1R) activation on self-renewal, proliferation and neuronal differentiation in mouse neonatal subventricular zone (SVZ) stem/progenitor cell cultures.

There is an emerging consensus that endocannabinoid signaling plays a major role in adult neurogenesis.

Cannabinoids act on at least two types of receptors, the type 1 and type 2 cannabinoid receptors (CB1R and CB2R), which are, respectively, predominantly distributed in the central nervous system (CNS) and immune system, although some studies have described the presence of low levels of CB2R in the brain.

Taken together, these results demonstrate that CB1R activation induces proliferation, self-renewal and neuronal differentiation from mouse neonatal SVZ cell cultures.

 Collectively, CB1R agonists render neurons less excitable and thus promote neuroprotection.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3660454/

Endocannabinoids in the gut.

“The endocannabinoid system mainly consists of endogenously produced cannabinoids (endocannabinoids) and two G protein-coupled receptors (GPCRs), cannabinoid receptors 1 and 2 (CB1 and CB2). This system also includes enzymes responsible for the synthesis and degradation of endocannabinoids and molecules required for the uptake and transport of endocannabinoids. In addition, endocannabinoid-related lipid mediators and other putative endocannabinoid receptors, such as transient receptor potential channels and other GPCRs have been identified. Accumulating evidence indicates that the endocannabinoid system is a key modulator of gastrointestinal physiology, influencing satiety, emesis, immune function, mucosal integrity, motility, secretion, and visceral sensation. In light of therapeutic benefits of herbal and synthetic cannabinoids, the vast potential of the endocannabinoid system for the treatment of gastrointestinal diseases has been demonstrated. This review focuses on the role of the endocannabinoid system in gut homeostasis and in the pathogenesis of intestinal disorders associated with intestinal motility, inflammation and cancer. Finally, links between gut microorganisms and the endocannabinoid system are briefly discussed.”

http://www.ncbi.nlm.nih.gov/pubmed/27538961

Endocannabinoid dysregulation in cognitive and stress-related brain regions in the Nrg1 mouse model of schizophrenia.

 

“The endocannabinoid system is dysregulated in schizophrenia.

These results demonstrate for the first time in vivo interplay between Nrg1 and endocannabinoids in the brain.

Our results demonstrate that aberrant Nrg1 and endocannabinoid signalling may cooperate in the hippocampus to impair cognition in schizophrenia, and that Nrg1 deficiency alters endocannabinoid signalling in brain stress circuitry.”

http://www.ncbi.nlm.nih.gov/pubmed/27521758

Metabolism of endocannabinoids.

“Endocannabinoids belong to a group of ester, ether and amide derivatives of fatty acids, which are endogenous ligands of receptors CB1, CB2, TRPV1 and GPR55 that are included in the endocannabinoid system of the animal organism. The best known endocannabinoids are: N-arachidonylethanolamide called anandamide (AEA) and 2-arachidonoylglycerol (2-AG). They occur in all organisms, and their highest level is observed in the brain. In this review the mechanisms of synthesis and degradation of both AEA and 2-AG are shown. Endocannabinoids are synthesized from phospholipids (mainly phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol) located in the cell membrane. As a result of arachidonic acid transfer from phosphatidylcholine to phosphatidylethanolamine, N-arachidonoyl phosphatidylethanolamine is formed, which is hydrolyzed to AEA by phospholipase D, C and A2. However, 2-AG is formed during the hydrolysis of phosphatidylinositol catalyzed mainly by DAGL. The primary role of endocannabinoids is the activation of cannabinoid receptors. Both AEA and 2-AG are primarily agonists of the CB1 receptor and to a lower degree CB2 and TRPV1r eceptors, but 2-AG has stronger affinity for these receptors. Through activation of receptors, endocannabinoids affect cellular metabolism and participate in the metabolic processes by receptor-independent pathways. Endocannabinoids which are not bound to the receptors are degraded. The main enzymes responsible for the hydrolysis of AEA and 2-AG are FAAH and MAGL, respectively. Apart from hydrolytic degradation, endocannabinoids may also be oxidized by cyclooxygenase-2, lipoxygenases, and cytochrome P450. It has been shown that the metabolites of both endocannabinoids also have biological significance.”

http://www.ncbi.nlm.nih.gov/pubmed/27516570

Synthesis and Biological Evaluation of Thiophene-Based Cannabinoid Receptor Type 2 Radiotracers for PET Imaging.

“Over the past two decades, our understanding of the endocannabinoid system has greatly improved due to the wealth of results obtained from exploratory studies. Currently, two cannabinoid receptor subtypes have been well-characterized. The cannabinoid receptor type 1 (CB1) is widely expressed in the central nervous system, while the levels of the cannabinoid receptor type 2 (CB2) in the brain and spinal cord of healthy individuals are relatively low.”

http://www.ncbi.nlm.nih.gov/pubmed/27512365

Cross-validated stable-isotope dilution GC-MS and LC-MS/MS assays for monoacylglycerol lipase (MAGL) activity by measuring arachidonic acid released from the endocannabinoid 2-arachidonoyl glycerol.

“2-Arachidonoyl glycerol (2AG) is an endocannabinoid that activates cannabinoid (CB) receptors CB1 and CB2. Monoacylglycerol lipase (MAGL) inactivates 2AG through hydrolysis to arachidonic acid (AA) and glycerol, thus modulating the activity at CB receptors.” http://www.ncbi.nlm.nih.gov/pubmed/27511795

Medical Marijuana-Opportunities and Challenges

“Over the recent years, public and political opinions have demonstrated increasing support for the legalization of medical marijuana.

To date, 24 states as well as the District of Columbia have legalized cannabis for medical use, 4 states have legalized the recreational use of Marijuana.

Marijuana is derived from the hemp plant Cannabis sativa. Δ-9-tetrahydrocannabinol (THC) is the major psychoactive constituent of cannabis, while cannabidiol (CBD) is the major non-psychoactive constituent. THC is a partial agonist at CB1 and CB2 receptors, while CBD at high levels is an antagonist CB1 and CB2.

CB1 is abundantly expressed in the brain, and CB2 is expressed on immune cells (expression of CB2 on neurons remains controversial). The brain also produces endogenous cannabis-like substances (endocannabinoids) that bind and activate the CB1/CB2 receptors.

There is tremendous interest in harnessing the therapeutic potential of plant-derived and synthetic cannabinoids.

This Editorial provides an overview of diseases that may be treated by cannabinoids.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4948749/