Category Archives: Endocannabinoid System

[The endocannabinoid system role in the pathogenesis of obesity and depression].

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“Excessive consumption and obesity do not always have to be strictly pathological. The adjustment of food intake as well as the pleasure of eating are the results of the circulation of neurotransmitters, hormones and glucocorticoids which have an ability to regulate the activity of many receptors connected with G protein, including endocannabinoid receptors.

The key role of endocannabinoids in pathogenesis of obesity is their overproduction by adipose cells.

Endocannabinoids (eCBs) affect CB1 receptors and increase hunger, willingness to intake food, decrease peristalsis and delay stomach emptying.

In obese people increased levels of both central and peripheral endocannabinoids are observed. It may be connected with higher availability of endocannabinoid precursors to synthesis from adipose tissue and lipids.

Raised concentration of eCBs in the body may be the consequence of their catabolism dysfunction. There is a positive correlation between amount the number of receptors in the peripheral tissues and obesity increase.

It is thought that expression of CB1 receptors in mesolimbic system is connected with motivation to consume food in response to rewarding factor.

The appetite increase after cannabinoids use is probably caused by rewarding action of the consumed food and it results from excessive dopaminergic transmission in award system.

The pharmacological inhibition of endocannabinoids activity leads to weight loss, but may also have negative consequences such as decreased mood, reduced tolerance of pain, intensified anxiety, anhedonia, depressive symptoms, even suicidal thoughts.

In post mortem examinations a decrease in CB1 receptor density in grey matter of glial cells in patients with major depression was identified. The pleiotropic and extensive activity of endocannabinoid system can influence a range of neurotransmitters thereby modulating the psychiatric life phenomena, simultaneously being involved in metabolism control and energetic system of human body.

Hence it is a link between metabolic disorders and depression and anxiety disorders. Therefore, in obese people depressive comorbidity is higher and it significantly worsens prognosis and decreases life quality.”

http://www.ncbi.nlm.nih.gov/pubmed/26277182

Synthesis and biological evaluation of (3′,5′-dichloro-2,6-dihydroxy-biphenyl-4-yl)-aryl/alkyl-methanone selective CB2 inverse agonist.

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“Cannabinoid receptor 2 (CB2) selective agonists and inverse agonists possess significant potential as therapeutic agents for regulating inflammation and immune function.

Although CB2 agonists have received the greatest attention, it is emerging that inverse agonists also manifest anti-inflammatory activity.

In process of designing new cannabinoid ligands we discovered that the 2,6-dihydroxy-biphenyl-aryl methanone scaffold imparts inverse agonist activity at CB2 receptor without functional activity at CB1. To further explore the scaffold we synthesized a series of (3′,5′-dichloro-2,6-dihydroxy-biphenyl-4-yl)-aryl/alkyl-methanone analogs and evaluated the CB1 and CB2 affinity, potency, and efficacy.

The studies reveal that an aromatic C ring is required for inverse agonist activity and that substitution at the 4 position is optimum. The resorcinol moiety is required for optimum CB2 inverse agonist activity and selectivity. Antagonist studies against CP 55,940 demonstrate that the compounds 41 and 45 are noncompetitive antagonists at CB2.”

http://www.ncbi.nlm.nih.gov/pubmed/26275680

Cannabinoids for the Treatment of Agitation and Aggression in Alzheimer’s Disease.

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“Alzheimer’s disease (AD) is frequently associated with neuropsychiatric symptoms (NPS) such as agitation and aggression, especially in the moderate to severe stages of the illness. The limited efficacy and high-risk profiles of current pharmacotherapies for the management of agitation and aggression in AD have driven the search for safer pharmacological alternatives.

Over the past few years, there has been a growing interest in the therapeutic potential of medications that target the endocannabinoid system (ECS).

The behavioural effects of ECS medications, as well as their ability to modulate neuroinflammation and oxidative stress, make targeting this system potentially relevant in AD.

This article summarizes the literature to date supporting this rationale and evaluates clinical studies investigating cannabinoids for agitation and aggression in AD.

Letters, case studies, and controlled trials from four electronic databases were included. While findings from six studies showed significant benefits from synthetic cannabinoids-dronabinol or nabilone-on agitation and aggression, definitive conclusions were limited by small sample sizes, short trial duration, and lack of placebo control in some of these studies.

Given the relevance and findings to date, methodologically rigorous prospective clinical trials are recommended to determine the safety and efficacy of cannabinoids for the treatment of agitation and aggression in dementia and AD.”

The Endocannabinoid System and its Modulation by Phytocannabinoids

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“The endocannabinoid system is currently defined as the ensemble of the two 7-transmembrane-domain and G protein-coupled receptors for Δ9-tetrahydrocannabinol (but not for most other plant cannabinoids or phytocannabinoids)—cannabinoid receptor type-1 (CB1R) and cannabinoid receptor type-2 (CB2R); their two most studied endogenous ligands, the “endocannabinoids” N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol (2-AG); and the enzymes responsible for endocannabinoid metabolism.

However, anandamide and 2-AG, and also the phytocannabinoids, have more molecular targets than just CB1R and CB2R.

Furthermore, the endocannabinoids, like most other lipid mediators, have more than just one set of biosynthetic and degrading pathways and enzymes, which they often share with “endocannabinoid-like” mediators that may or may not interact with the same proteins as Δ9-tetrahydrocannabinol and other phytocannabinoids.

In some cases, these degrading pathways and enzymes lead to molecules that are not inactive and instead interact with other receptors.

Finally, some of the metabolic enzymes may also participate in the chemical modification of molecules that have very little to do with endocannabinoid and cannabinoid targets.

Here, we review the whole world of ligands, receptors, and enzymes, a true “endocannabinoidome”, discovered after the cloning of CB1R and CB2R and the identification of anandamide and 2-AG, and its interactions with phytocannabinoids.”

http://www.ncbi.nlm.nih.gov/pubmed/26271952

http://link.springer.com/article/10.1007%2Fs13311-015-0374-6

Safety and Toxicology of Cannabinoids.

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“There is extensive research on the safety, toxicology, potency, and therapeutic potential of cannabis.

However, uncertainty remains facilitating continued debate on medical and recreational cannabis policies at the state and federal levels.

This review will include a brief description ofcannabinoids and the endocannabinoid system; a summary of the acute and long-term effects of cannabis; and a discussion of the therapeutic potential of cannabis.

The conclusions about safety and efficacy will then be compared with the current social and political climate to suggest future policy directions and general guidelines.”

http://www.ncbi.nlm.nih.gov/pubmed/26269228

Dissecting the cannabinergic control of behavior: The where matters.

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“The endocannabinoid system is the target of the main psychoactive component of the plant Cannabis sativa, the Δ9 -tetrahydrocannabinol (THC).

This system is composed by the cannabinoid receptors, the endogenous ligands, and the enzymes involved in their metabolic processes, which works both centrally and peripherally to regulate a plethora of physiological functions.

This review aims at explaining how the site-specific actions of the endocannabinoid system impact on memory and feeding behavior through the cannabinoid receptors 1 (CB1 R).

Centrally, CB1 R is widely distributed in many brain regions, different cell types (e.g. neuronal or glial cells) and intracellular compartments (e.g. mitochondria).

Interestingly, cellular and molecular effects are differentially mediated by CB1 R according to their cell-type localization (e.g. glutamatergic or GABAergic neurons).

Thus, understanding the cellular and subcellular function of CB1 R will provide new insights and aid the design of new compounds in cannabinoid-based medicine.”

http://www.ncbi.nlm.nih.gov/pubmed/26260530

On the effects of CP 55-940 and other cannabinoid receptor agonists in C6 and U373 cell lines.

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“Cannabinoid receptor (CBs) agonists affect the growth of tumor cells via activation of deadly cascades. The spectrum of action of these agents and the precise role of the endocannabinoid system (ECS) on oncogenic processes remain elusive.

Herein we compared the effects of synthetic (CP 55-940 and WIN 55,212-2) and endogenous (anandamide or AEA) CBs agonists (10-20 μM) on morphological changes, cell viability, and induction of apoptosis in primary astrocytes and in two glioblastoma cell lines (C6 and U373 cells) in order to characterize their possible differential actions on brain tumor cells.

None of the CBs agonist tested induced changes in cell viability or morphology in primary astrocytes.

In contrast, CP 55-940 significantly decreased cell viability in C6 and U373 cells at 5 days of treatment, whereas AEA and WIN 55,212-2 moderately decreased cell viability in both cell lines. Treatment of U373 and C6 for 3 and 5 days with AEA or WIN 55,212-2 produced discrete morphological changes in cell bodies, whereas the exposure to CP 55-940 induced soma degradation. CP 55-940 also induced apoptosis in both C6 and U373 cell lines.

Our results support a more effective action of CP 55-940 to produce cell death of both cell lines through apoptotic mechanisms. Comparative aspects between cannabinoids with different profiles are necessary for the design of potential treatments against glial tumors.”

http://www.ncbi.nlm.nih.gov/pubmed/26255146

Microinjection of orexin-A into the rat locus coeruleus nucleus induces analgesia via cannabinoid type-1 receptors.

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“Locus coeruleus (LC) nucleus is involved in noradrenergic descending pain modulation.

LC receives dense orexinergic projections from the lateral hypothalamus. Orexin-A and -B are hypothalamic peptides which modulate a variety of brain functions via orexin type-1 (OX1) and orexin type-2 (OX2) receptors.

Previous studies have shown that activation of OX1 receptors induces endocannabinoid synthesis and alters synaptic neurotransmission by retrograde signaling via affecting cannabinoid type-1 (CB1) receptors.

In the present study the interaction of orexin-A and endocannabinoids was examined at the LC level in a rat model of inflammatory pain…

This data show that, activation of OX1 receptors in the LC can induce analgesia and also the blockade of OX1 or CB1 receptors is associated with hyperalgesia during formalin test.

Our findings also suggest that CB1 receptors may modulate the analgesic effect of orexin-A.

These results outline a new mechanism by which orexin-A modulates the nociceptive processing in the LC nucleus.”

http://www.ncbi.nlm.nih.gov/pubmed/26254729

The role of the peripheral cannabinoid system in the pathogenesis of detrusor overactivity evoked by increased intravesical osmolarity in rats.

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“The cannabinoid receptors CB1 and CB2 are localized in the urinary bladder and play a role in the regulation of its function. We investigated the pathomechanisms through which hyperosmolarity induces detrusor overactivity (DO)…

These results demonstrate that hyperosmolar-induced DO is mediated by CB1 and CB2 receptors. Therefore, the cannabinoid pathway could potentially be a target for the treatment of urinary bladder dysfunction.”

http://www.ncbi.nlm.nih.gov/pubmed/26243021

Cannabis, Cannabinoids, and Cerebral Metabolism: Potential Applications in Stroke and Disorders of the Central Nervous System.

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“No compound has generated more attention in both the scientific and recently in the political arena as much as cannabinoids.

These diverse groups of compounds referred collectively as cannabinoids have both been vilified due to its dramatic and potentially harmful psychotropic effects and glorified due to its equally dramatic and potential application in a number of acute and chronic neurological conditions.

Previously illegal to possess, cannabis, the plant where natural form of cannabinoids are derived, is now accepted in a growing number of states for medicinal purpose, and some even for recreational use, increasing opportunities for more scientific experimentation.

The purpose of this review is to summarize the growing body of literature on cannabinoids and to present an overview of our current state of knowledge of the human endocannabinoid system in the hope of defining the future of cannabinoids and its potential applications in disorders of the central nervous system, focusing on stroke.”

http://www.ncbi.nlm.nih.gov/pubmed/26238742