Category Archives: Endocannabinoid System

Effect of anandamide in Plasmodium Berghei-infected mice.

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“Eryptosis, the suicidal death of erythrocytes, is characterized by exposure of phosphatidylserine at the erythrocyte surface and cell shrinkage.

Triggers of eryptosis include anandamide.

Enhanced eryptosis of infected human erythrocytes is expected to delay the development of parasitaemia during infection with Plasmodium, the parasite causing malaria.

The present experiments aimed to test, whether anandamide influences eryptosis, parasite growth and/or host survival during in vitro or in vivo infection with Plasmodia.

In vivo administration of anandamide blunted the parasitaemia and significantly enhanced the survival of P. berghei-infected mice.

In conclusion, anandamide stimulated eryptosis of infected erythrocytes thus counteracting parasitaemia and a lethal course of the disease.”

http://www.ncbi.nlm.nih.gov/pubmed/20798520

Cannabinoid receptor 2 modulates susceptibility to experimental cerebral malaria through a CCL17-dependent mechanism.

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“Cerebral malaria (CM) is a severe and often fatal complication of Plasmodium falciparum infection. It is characterized by parasite sequestration, a breakdown of the blood-brain-barrier and a strong inflammation in the brain.

We investigated the role of the cannabinoid receptor 2 (CB2), an important modulator of neuroinflammatory responses, in experimental cerebral malaria (ECM).

Strikingly, mice with a deletion of the CB2-encoding gene (Cnr2-/-) mice inoculated with Plasmodium berghei ANKA-erythrocytes exhibited enhanced survival and a diminished blood-brain-barrier disruption.

Therapeutic application of a specific CB2 antagonist also conferred increased ECM resistance in wild type mice.

Hematopoietic-derived immune cells were responsible for the enhanced protection in bone-marrow-chimeric (BM)-Cnr2-/- mice. Mixed BM-chimeras further revealed that CB2-expressing cells contributed to ECM development. A heterogeneous CD11b+ cell population, containing macrophages and neutrophils, expanded in the Cnr2-/- spleen after infection and expressed macrophage mannose receptors, arginase-1 activity and IL-10.

Also in the Cnr2-/-brain CD11b+ cells that expressed selected anti-inflammatory markers accumulated and expression of inflammatory mediators IFN-γ and TNF-α was reduced.

Finally, the M2-macrophage chemokine CCL17 was identified as essential factor for enhanced survival in the absence of CB2, since CCL17 x Cnr2 double-deficient mice were fully susceptible to ECM.

Thus, targeting CB2 may be promising for the development of alternative treatment regimes of ECM.”

http://www.ncbi.nlm.nih.gov/pubmed/27474745

Selective activation of CB2 receptor improves efferocytosis in cultured macrophages.

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“Recent evidence indicates that the defective ability to clear apoptotic cells by macrophages (efferocytosis) and the resultant apoptotic cells accumulation in atherosclerotic plaques play an important role during the progression of unstable plaques.

The cannabinoid type 2 receptor (CB2), has recently been emerging as a new target to reduce vulnerability and promote stability of plaques, however, the underlying mechanisms have not been studied in detail. In the present study, we investigated whether selective activation of CB2 improves efferocytosis of macrophages.

SIGNIFICANCE:

The selective activation of CB2 improves efferosytosis of normal-cultured and OxLDL-loaded macrophages, which might provide a novel mechanism on how CB2 activation reduces vulnerability and promotes stability of atherosclerotic plaques.”

http://www.ncbi.nlm.nih.gov/pubmed/27474129

The therapeutic potential of the phytocannabinoid cannabidiol for Alzheimer’s disease.

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“Alzheimer’s disease (AD) is the most common neurodegenerative disorder, characterized by progressive loss of cognition. Over 35 million individuals currently have AD worldwide. Unfortunately, current therapies are limited to very modest symptomatic relief.

The brains of AD patients are characterized by the deposition of amyloid-β and hyperphosphorylated forms of tau protein. AD brains also show neurodegeneration and high levels of oxidative stress and inflammation.

The phytocannabinoid cannabidiol (CBD) possesses neuroprotective, antioxidant and anti-inflammatory properties and reduces amyloid-β production and tau hyperphosphorylation in vitro.

CBD has also been shown to be effective in vivo making the phytocannabinoid an interesting candidate for novel therapeutic interventions in AD, especially as it lacks psychoactive or cognition-impairing properties.

CBD treatment would be in line with preventative, multimodal drug strategies targeting a combination of pathological symptoms, which might be ideal for AD therapy.

Thus, this review will present a brief introduction to AD biology and current treatment options before outlining comprehensively CBD biology and pharmacology, followed by in-vitro and in-vivo evidence for the therapeutic potential of CBD. We will also discuss the role of the endocannabinioid system in AD before commenting on the potential future of CBD for AD therapy (including safety aspects).”

http://www.ncbi.nlm.nih.gov/pubmed/27471947

Cannabinoids in pain and inflammation.

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“Cannabinoids exhibit medicinal properties including analgesic, anti-inflammatory and immunosuppressive properties. This paper reviews some of the recent findings in the study of cannabinoids in pain and inflammation. Some of the effects of cannabinoids are receptor mediated and others are receptor independent. Endocannabinoids naturally reduce pain and are cerebroprotective. Natural and synthetic cannabinoids have the potential to reduce nociception, reverse the development of allodynia and hyperalgesia, reduce inflammation and inflammatory pain and protect from secondary tissue damage in traumatic head injury.”

http://www.ncbi.nlm.nih.gov/pubmed/15265314

The future of cannabinoids as analgesic agents: a pharmacologic, pharmacokinetic, and pharmacodynamic overview.

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“For thousands of years, physicians and their patients employed cannabis as a therapeutic agent.

Despite this extensive historical usage, in the Western world, cannabis fell into disfavor among medical professionals because the technology available in the 1800s and early 1900s did not permit reliable, standardized preparations to be developed.

However, since the discovery and cloning of cannabinoid receptors (CB1 and CB2) in the 1990s, scientific interest in the area has burgeoned, and the complexities of this fascinating receptor system, and its endogenous ligands, have been actively explored.

Recent studies reveal that cannabinoids have a rich pharmacology and may interact with a number of other receptor systems-as well as with other cannabinoids-to produce potential synergies.

Cannabinoids-endocannabinoids, phytocannabinoids, and synthetic cannabinoids-affect numerous bodily functions and have indicated efficacy of varying degrees in a number of serious medical conditions.

Cannabinoid receptor agonists and/or molecules that affect the modulation of endocannabinoid synthesis, metabolism, and transport may, in the future, offer extremely valuable tools for the treatment of a number of currently intractable disorders.”

 http://www.ncbi.nlm.nih.gov/pubmed/17890938

Blood pressure regulation by endocannabinoids and their receptors

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“Cannabinoids and their endogenous and synthetic analogs exert powerful hypotensive and cardiodepressor effects by complex mechanisms involving direct and indirect effects on myocardium and vasculature.

On the one hand, endocannabinoids and cannabinoid receptors have been implicated in the hypotensive state associated with hemorrhagic, endotoxic and cardiogenic shock, and advanced liver cirrhosis.

On the other hand, there is emerging evidence suggesting that the endocannabinergic system plays an important role in the cardiovascular regulation in hypertension.

This review is aimed to discuss the in vivo hypotensive and cardiodepressant effects of cannabinoids mediated by cannabinoid and TRPV1 receptors, and focuses on the novel therapeutical strategies offered by targeting the endocannabinoid system in the treatment of hypertension.

The endocannabinergic system plays an important cardiovascular regulatory role not only in pathophysiological conditions associated with excessive hypotension but also in hypertension.

Thus, the pharmacological manipulation of this system may offer novel therapeutic approaches in a variety of cardiovascular disorders.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2225528/

A frequent polymorphism in the coding exon of the human cannabinoid receptor (CNR1) gene.

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“The central cannabinoid receptor (CB1) mediates the pharmacological activities of cannabis, the endogenous agonist anandamide and several synthetic agonists.

The cloning of the human cannabinoid receptor (CNR1) gene facilitates molecular genetic studies in disorders like Gilles de la Tourette syndrome (GTS), obsessive compulsive disorder (OCD), Parkinsons disease, Alzheimers disease or other neuro psychiatric or neurological diseases, which may be predisposed or influenced by mutations or variants in the CNR1 gene.

We detected a frequent silent mutation (1359G–>A) in codon 453 (Thr) of the CNR1 gene that turned out to be a common polymorphism in the German population. Allele frequencies of this polymorphism are 0.76 and 0.24, respectively.

We developed a simple and rapid polymerase chain reaction (PCR)-based assay by artificial creation of a Msp I restriction site in amplified wild-type DNA (G-allele), which is destroyed by the silent mutation (A-allele).

The intragenic CNR1 polymorphism 1359(G/A) should be useful for association studies in neuro psychiatric disorders which may be related to anandamide metabolism disturbances.”

http://www.ncbi.nlm.nih.gov/pubmed/10441206

Endocannabinoid analogues exacerbate marble-burying behavior in mice via TRPV1 receptor.

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“Activation of cannabinoid CB(1) receptor is shown to inhibit marble-burying behavior (MBB), a behavioral model for assessing obsessive-compulsive disorder (OCD).

Anandamide, an endogenous agonist at CB(1) receptor also activates the transient receptor potential vanilloid type 1 (TRPV1) channels but at a higher concentration.

Furthermore, anandamide-mediated TRPV1 effects are opposite to that of the CB(1) receptor. Therefore, the present study was carried out to investigate the influence of low and high doses of anandamide on MBB in CB(1) and TRPV1 antagonist pre-treated mice.

Thus, the study indicates the biphasic influence of anandamide on MBB, and chronic administration of capsazepine either alone or with URB597 might be an effective tool in the treatment of OCD.”

http://www.ncbi.nlm.nih.gov/pubmed/22248639

Facilitation of CB1 receptor-mediated neurotransmission decreases marble burying behavior in mice.

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“Obsessive-compulsive disorder (OCD) is a common psychiatric disorder characterized by the occurrence of obsessions and compulsions.

Glutamatergic abnormalities have been related to the pathophysiology of OCD.

Cannabinoids inhibit glutamate release in the central nervous system, but the involvement of drugs targeting the endocannabinoid system has not yet been tested in animal models of repetitive behavior.

Thus, the aim of the present study was to verify the effects of the CB1 receptor agonist WIN55,212-2, the inhibitor of anandamide uptake AM404 and the anandamide hydrolysis inhibitor URB597, on compulsive-associate behavior in male C57BL/6J mice submitted to the marble burying test (MBT), an animal model used for anti-compulsive drug screening.

These results suggest a potential role for drugs acting on the cannabinoid system in modulating compulsive behavior.”

http://www.ncbi.nlm.nih.gov/pubmed/21111767