Tag Archives: Cannabinoids

Orexin-A represses satiety-inducing POMC neurons and contributes to obesity via stimulation of endocannabinoid signaling.

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“In the hypothalamic arcuate nucleus (ARC), proopiomelanocortin (POMC) neurons and the POMC-derived peptide α-melanocyte-stimulating hormone (α-MSH) promote satiety. POMC neurons receive orexin-A (OX-A)-expressing inputs and express both OX-A receptor type 1 (OX-1R) and cannabinoid receptor type 1 (CB1R) on the plasma membrane.

OX-A is crucial for the control of wakefulness and energy homeostasis and promotes, in OX-1R-expressing cells, the biosynthesis of the endogenous counterpart of marijuana’s psychotropic and appetite-inducing component Δ9-tetrahydrocannabinol, i.e., the endocannabinoid 2-arachidonoylglycerol (2-AG), which acts at CB1R.

We report that OX-A/OX-1R signaling at POMC neurons promotes 2-AG biosynthesis, hyperphagia, and weight gain by blunting α-MSH production via CB1R-induced and extracellular-signal-regulated kinase 1/2 activation- and STAT3 inhibition-mediated suppression ofPomcgene transcription. Because the systemic pharmacological blockade of OX-1R by SB334867 caused anorectic effects by reducing food intake and body weight, our results unravel a previously unsuspected role for OX-A in endocannabinoid-mediated promotion of appetite by combining OX-induced alertness with food seeking. Notably, increased OX-A trafficking was found in the fibers projecting to the ARC of obese mice (ob/oband high-fat diet fed) concurrently with elevation of OX-A release in the cerebrospinal fluid and blood of mice.

Furthermore, a negative correlation between OX-A and α-MSH serum levels was found in obese mice as well as in human obese subjects (body mass index > 40), in combination with elevation of alanine aminotransferase and γ-glutamyl transferase, two markers of fatty liver disease.

These alterations were counteracted by antagonism of OX-1R, thus providing the basis for a therapeutic treatment of these diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/27071101

Cannabinoid Receptors CB1 and CB2 Modulate the Electroretinographic Waves in Vervet Monkeys.

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“The expression patterns of the cannabinoid receptor type 1 (CB1R) and the cannabinoid receptor type 2 (CB2R) are well documented in rodents and primates.

In vervet monkeys, CB1R is present in the retinal neurons (photoreceptors, horizontal cells, bipolar cells, amacrine cells, and ganglion cells) and CB2R is exclusively found in the retinal glia (Müller cells). However, the role of these cannabinoid receptors in normal primate retinal function remains elusive.

Using full-field electroretinography in adult vervet monkeys, we recorded changes in neural activity following the blockade of CB1R and CB2R by the intravitreal administration of their antagonists (AM251 and AM630, resp.) in photopic and scotopic conditions.

Our results show that AM251 increases the photopic a-wave amplitude at high flash intensities, whereas AM630 increases the amplitude of both the photopic a- and b-waves.In scotopic conditions, both blockers increased the b-wave amplitude but did not change the a-wave amplitude.

These findings suggest an important role of CB1R and CB2R in primate retinal function.”

http://www.ncbi.nlm.nih.gov/pubmed/27069692

Analysis of endocannabinoid signaling elements and related proteins in lymphocytes of patients with Dravet syndrome.

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“Cannabidiol (CBD) reduces seizures in childhood epilepsy syndromes including Dravet syndrome (DS).

A formulation of CBD has obtained orphan drug designation for these syndromes and clinical trials are currently underway.

We believe of interest to investigate whether these potential targets are altered in DS, in particular whether the endocannabinoid system is dysregulated. To this end, lymphocytes from patients and controls were used for analysis of gene expression of transmitter receptors and transporters, ion channels, and enzymes associated with CBD effects, as well as endocannabinoid genes.

In conclusion, together with changes in the voltage-dependent calcium channel α-1h subunit, we found an upregulation of CB 2 receptors, associated with an activation of lymphocytes and changes in inflammation-related genes, in DS patients. Such changes were also reported in inflammatory disorders and may indirectly support the occurrence of a potential dysregulation of the endocannabinoid system in the brain.”

http://www.ncbi.nlm.nih.gov/pubmed/27069631

http://www.thctotalhealthcare.com/category/dravet-syndome/

Targeting the cannabinoid CB2 receptor to attenuate the progression of motor deficits in LRRK2-transgenic mice.

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“Most of cases of Parkinson’s disease (PD) have a sporadic origin, with their causes mostly unknown, although overexposure to some environmental factors has been found to occur in some cases. Other forms of parkinsonism are the consequence of dominant or recessive mutations in specific genes, e.g. α-synuclein, parkin and, more recently, leucine-rich repeat kinase 2 (LRRK2), whose G2019S mutation represents the most prevalent form of late-onset, autosomal dominant familial PD.

A transgenic mouse model expressing the G2019S mutation of LRRK2 is already available and apparently may represent a valuable experimental model for investigating PD pathogenesis and novel treatments.

We designed a long-term study with these animals aimed at: (i) elucidating the changes experienced by the endocannabinoid signaling system in the basal ganglia during the progression of the disease in these mice, paying emphasis in the CB2 receptor, which has emerged as a promising target in PD, and (ii) evaluating the potential of compounds selectively activating this CB2 receptor, as disease-modifying agents in these mice.

Our results unequivocally demonstrate that LRRK2 transgenic mice develop motor impairment consisting of small anomalies in rotarod performance (presumably reflecting a deficit in motor coordination and dystonia) and a strong deficiency in the hanging-wire test (reflecting muscle weakness), rather than hypokinesia which was difficult to be demonstrated in the actimeter. These behavioral responses occurred in absence of any evidence of reactive gliosis and neuronal losses, as well as synaptic deterioration in the basal ganglia, except an apparent impairment in autophagy reflected by elevated LAMP-1 immunolabelling in the striatum and substantia nigra.

Furthermore, there were no changes in the status of the CB2 receptor, as well as in other elements of the endocannabinoid signaling, in the basal ganglia, but, paradoxically, the selective activation of this receptor partially reversed the deficits in the hanging-wire test of LRRK2 transgenic mice. This was accompanied by normalization in LAMP-1 immunolabelling in the basal ganglia, although it is possible that other CNS structures, remaining to be identified, are involved in the behavioral improvement.

In summary, our data support the interest of the CB2 receptor as a potential pharmacological target in LRRK2 transgenic mice, although the neuronal substrates underlying these benefits might be not completely related to the basal ganglia and to the presumed parkinsonian features of these mice.”  http://www.ncbi.nlm.nih.gov/pubmed/27063942

Cannabinoid receptor 1 controls human mucosal-type mast cell degranulation and maturation in situ.

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“Because many chronic inflammatory and allergic disorders are intimately linked to excessive mast cell (MC) numbers and activation, it is clinically important to understand the physiologic mechanisms preventing excess MC accumulation/degranulation in normal human tissues.

Because endocannabinoids are increasingly recognized as neuroendocrine regulators of MC biology, we investigated how cannabinoid receptor (CB) 1 signaling affects human mucosal-type mast cells (hMMCs).

In human airway mucosa hMMC activation and maturation are subject to a potent inhibitory endocannabinoid tone through CB1 stimulation.

This invites one to target the endocannabinoid system in human airway mucosa as a novel strategy in the future management of allergic diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/23453134

Endocannabinoids and immune regulation

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“Cannabinoid pharmacology has made important advances in recent years after the discovery of the cannabinoid receptors.

These discoveries have added to our understanding of exogenous and endogenous cannabinoid signaling along with exploring the various pathways of their biosynthesis, molecular structure, inactivation, and anatomical distribution of their receptors throughout the body.

The endocannabinoid system is involved in immunoregulation and neuroprotection.

The discovery of cannabinoid receptors occurring naturally throughout the vertebrate body and the availability of highly selective and potent canabimimetics led to the identification of a naturally occurring lipid signaling system termed the endocannabinoid system.

Interestingly, the endocannabinoid system dates back very long in the evolution because it exists as an ancient plant signaling system regulating the plant immunity-related genes in response to infection and stress.

The main pharmacological functions of the endocannabinoid system include neuromodulation, controlling motor functions, cognition, emotional responses, homeostasis and motivation. However, in the periphery, this system is an important modulator of autonomic nervous system, the immune system and microcirculation.

There have been a number of recent studies which have demonstrated that the endocannabinoids have both inhibitory effects and stimulatory impact on the immune system and may be actually important in homeostasis or control of the immune reactions.

 The image of endocannabinoid system now appears to be of a modulatory complex which affects the physiological functions in peripheral tissues and can thus be considered as a potential therapeutic target in the future.
Thus, manipulation of endocannabinoids in vivo may constitute a novel treatment modality against inflammatory disorders.”
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3044336/

Distinctive effects of eicosapentaenoic and docosahexaenoic acids in regulating neural stem cell fate are mediated via endocannabinoid signalling pathways.

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“Emerging evidence suggests a complex interplay between the endocannabinoid system, omega-3 fatty acids and the immune system in the promotion of brain self-repair.

However, it is unknown if all omega-3 fatty acids elicit similar effects on adult neurogenesis and if such effects are mediated or regulated by interactions with the endocannabinoid system. This study investigated the effects of DHA and EPA on neural stem cell (NSC) fate and the role of the endocannabinoid signalling pathways in these effects.

EPA, but not DHA, significantly increased proliferation of NSCs compared to controls, an effect associated with enhanced levels of the endocannabinoid 2-arachidonylglycerol (2-AG) and p-p38 MAPK, effects attenuated by pre-treatment with CB1 (AM251) or CB2 (AM630) receptor antagonists.

Furthermore, in NSCs derived from IL-1β deficient mice, EPA significantly decreased proliferation and p-p38 MAPK levels compared to controls, suggesting a key role for IL-1β signalling in the effects observed. Although DHA similarly increased 2-AG levels in wild-type NSCs, there was no concomitant increase in proliferation or p-p38 MAPK activity. In addition, in NSCs from IL-1β deficient mice, DHA significantly increased proliferation without effects on p-P38 MAPK, suggesting effects of DHA are mediated via alternative signalling pathways.

These results provide crucial new insights into the divergent effects of EPA and DHA in regulating NSC proliferation and the pathways involved, and highlight the therapeutic potential of their interplay with endocannabinoid signalling in brain repair.”

http://www.ncbi.nlm.nih.gov/pubmed/27044662

The therapeutic use of cannabinoids: Forensic aspects.

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“Since 2013 in the Italian market has been introduced the Nabiximols, a drug containing two of the main active cannabinoids: Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). This drug has been approved in Italy in the treatment of Multiple Sclerosis (MS). It is an oral spray formulation and each puff of 100μl contains 2.7mg of Δ9-THC and 2.5mg of CBD.

In the present study we analyzed urine and blood samples collected from a group of 20 patients treated with Nabiximols in order to evaluate: blood Δ9-THC concentrations in relation to the dose administered and the duration of treatment and the potentiality of this medication to be used for drug habit.

The study was conducted on a sample group of patients affected by MS, of both sexes, age: 49-61 years, treated with Nabiximols for short (28 days) or long-term.

The results of our study allow affirming that it is unlikely to use this medication for drug habit or to sale it in the black market because of the low blood concentrations available and of its high costs.

These statements were confirmed by: (a) the low Δ9-THC concentrations in the pharmaceutical formulation; (b) the low blood concentrations produced by Nabiximols administration, more than 10 times smaller than the blood concentrations known to produce psychotropic effects; (c) the presence of CBD (Δ9-THC natural antagonist); (d) the route of administration (inhaled, not smoked).”

http://www.ncbi.nlm.nih.gov/pubmed/27038587

No more pain upon Gq-protein-coupled receptor activation: role of endocannabinoids.

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“Marijuana has been used to relieve pain for centuries.

The analgesic mechanism of its constituents, the cannabinoids, was only revealed after the discovery of cannabinoid receptors (CB1 and CB2) two decades ago.”

http://www.ncbi.nlm.nih.gov/pubmed/24494686

Cannabis and cancer: toward a new understanding

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“The treatment of cancer, including the disease itself and the symptoms associated with cancer and its therapy, is one of the most important emerging frontiers in cannabinoid therapeutics.

This Current Oncology supplement brings together the work of some of the leading minds around the world who have dedicated themselves and their laboratories to understanding the role of cannabis and cannabinoids in the pathophysiology and management of cancer.

It is an unfortunate reality of 2016 that many doctors still lack the basic knowledge about cannabis, cannabinoids, and the endocannabinoid system that would enable them to have an informed discussion with their patients, and that the knowledge gap gives rise to stigmatization, alienation, and a fracture of the doctor–patient relationship.

Our patient describes her experience in trying to find answers and assistance, and with the help of her treating oncologist, she succeeds in securing legal access to cannabinoids, with remarkable results. Stories of this kind are occurring too often to be ignored or written off as placebo responses or outliers. As a medical profession, we are duty-bound to follow up on such experiences with critical and balanced investigation.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4791146/