The Endocannabinoid System: An Osteopathic Perspective

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“A person is the product of dynamic interaction between body, mind, and spirit—This holistic principle is exemplified by cannabinoid receptors, which span the field of psychoneuroimmunology. Taken together, CB1, CB2, and their endocannabinoid ligands represent a microcosm of mind-body medicine. The primary purpose of the current article is to review the expanding endocannabinoid literature beginning with exogenous compounds—Cannabis and plant cannabinoids—and then shift to the endogenous system, highlighting embryology and development, neuroprotection, autonomics and immunity, inflammation, apoptosis, hunger and feeding, and nociception and pain.” http://jaoa.org/article.aspx?articleid=2093607

The multiplicity of action of cannabinoids: implications for treating neurodegeneration.

“The cannabinoid (CB) system is widespread in the central nervous system and is crucial for controlling a range of neurophysiological processes such as pain, appetite, and cognition. The endogenous CB molecules, anandamide, and 2-arachidonoyl glycerol, interact with the G-protein coupled CB receptors, CB(1) and CB(2).

These receptors are also targets for the phytocannabinoids isolated from the cannabis plant and synthetic CB receptor ligands.

The CB system is emerging as a key regulator of neuronal cell fate and is capable of conferring neuroprotection by the direct engagement of prosurvival pathways and the control of neurogenesis.

Many neurological conditions feature a neurodegenerative component that is associated with excitotoxicity, oxidative stress, and neuroinflammation, and certain CB molecules have been demonstrated to inhibit these events to halt the progression of neurodegeneration.

Such properties are attractive in the development of new strategies to treat neurodegenerative conditions of diverse etiology, such as Alzheimer’s disease, multiple sclerosis, and cerebral ischemia.

This article will discuss the experimental and clinical evidence supporting a potential role for CB-based therapies in the treatment of certain neurological diseases that feature a neurodegenerative component.”

http://www.ncbi.nlm.nih.gov/pubmed/20875047

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.”

The Endocannabinoid System in the Retina: From Physiology to Practical and Therapeutic Applications.

“Cannabis is one of the most prevalent drugs used in industrialized countries.

The main effects of Cannabis are mediated by two major exogenouscannabinoids: ∆9-tetrahydroxycannabinol and cannabidiol. They act on specific endocannabinoid receptors, especially types 1 and 2.

Mammals are endowed with a functional cannabinoid system including cannabinoid receptors, ligands, and enzymes.

This endocannabinoid signaling pathway is involved in both physiological and pathophysiological conditions with a main role in the biology of the central nervous system.

As the retina is a part of the central nervous system due to its embryonic origin, we aim at providing the relevance of studying the endocannabinoid system in the retina. Here, we review the distribution of the cannabinoid receptors, ligands, and enzymes in the retina and focus on the role of the cannabinoid system in retinal neurobiology.

This review describes the presence of the cannabinoid system in critical stages of retinal processing and its broad involvement in retinal neurotransmission, neuroplasticity, and neuroprotection.

Accordingly, we support the use of synthetic cannabinoids as new neuroprotective drugs to prevent and treat retinal diseases.

Finally, we argue for the relevance of functional retinal measures in cannabis users to evaluate the impact of cannabis use on human retinal processing.”

http://www.ncbi.nlm.nih.gov/pubmed/26881099

Functions of the CB1 and CB 2 receptors in neuroprotection at the level of the blood-brain barrier.

“The cannabinoid (CB) receptors are the main targets of the cannabinoids, which include plant cannabinoids, endocannabinoids and synthetic cannabinoids. Over the last few years, accumulated evidence has suggested a role of the CB receptors in neuroprotection.

The blood-brain barrier (BBB) is an important brain structure that is essential for neuroprotection. A link between the CB receptors and the BBB is thus likely, but this possible connection has only recently gained attention.

Cannabinoids and the BBB share the same mechanisms of neuroprotection and both protect against excitotoxicity (CB1), cell death (CB1), inflammation (CB2) and oxidative stress (possibly CB independent)-all processes that also damage the BBB.

Several examples of CB-mediated protection of the BBB have been found, such as inhibition of leukocyte influx and induction of amyloid beta efflux across the BBB.

Moreover, the CB receptors were shown to improve BBB integrity, particularly by restoring the tightness of the tight junctions. This review demonstrated that both CB receptors are able to restore the BBB and neuroprotection, but much uncertainty about the underlying signaling cascades still exists and further investigation is needed.”

http://www.ncbi.nlm.nih.gov/pubmed/24929655

Cannabinoids Promote Oligodendrocyte Progenitor Survival: Involvement of Cannabinoid Receptors and Phosphatidylinositol-3 Kinase/Akt Signaling

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“Cannabinoids exert pleiotropic actions in the CNS, including the inhibition of inflammatory responses and the enhancement of neuronal survival after injury… cannabinoid receptors are distributed widely in brain… Cannabinoids Promote Oligodendrocyte Progenitor Survival: Involvement of Cannabinoid Receptors and Phosphatidylinositol-3 Kinase/Akt Signaling.

Limited clinical studies have suggested that cannabis might ameliorate the symptomatology in multiple sclerosis patients, and beneficial effects of synthetic cannabinoids have been reported in vivoin rodent models of multiple sclerosis.

Apart from their actions on motor and pain pathways, cannabinoids regulate the immune response by reducing the production of inflammatory mediators by leukocytes, astrocytes, and microglia, which may contribute to their beneficial effects.

The results of the present study also point to a direct role of cannabinoids in promoting the survival of oligodendrocyte progenitors, particularly in unfavorable conditions, as would be the case in demyelinating diseases. Studies in progress are aimed to evaluate the function of cannabinoids in other models affecting oligodendroglial survival.

http://www.jneurosci.org/content/22/22/9742.long

Cannabidiol, neuroprotection and neuropsychiatric disorders.

“Cannabidiol (CBD) is a non-psychotomimetic phytocannabinoid derived from Cannabis sativa.

It has possible therapeutic effects over a broad range of neuropsychiatric disorders.

CBD attenuates brain damage associated with neurodegenerative and/or ischemic conditions.

It also has positive effects on attenuating psychotic-, anxiety- and depressive-like behaviors.

Moreover, CBD affects synaptic plasticity and facilitates neurogenesis.

The mechanisms of these effects are still not entirely clear but seem to involve multiple pharmacological targets.

In the present review, we summarized the main biochemical and molecular mechanisms that have been associated with the therapeutic effects of CBD, focusing on their relevance to brain function, neuroprotection and neuropsychiatric disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26845349

The Cannabinoid CB1/CB2 Agonist WIN55212.2 Promotes Oligodendrocyte Differentiation In Vitro and Neuroprotection During the Cuprizone-Induced Central Nervous System Demyelination.

“Different types of insults to the CNS lead to axon demyelination. Remyelination occurs when the CNS attempts to recover from myelin loss and requires the activation of oligodendrocyte precursor cells.

With the rationale that CB1 receptor is expressed in oligodendrocytes and marijuana consumption alters CNS myelination, we study the effects of the cannabinoid agonist WIN55212.2 in (1) an in vitro model of oligodendrocyte differentiation and (2) the cuprizone model for demyelination.

The cannabinoid agonist WIN55212.2 promotes oligodendrocyte differentiation in vitro.

Moreover, 0.5 mg/kg of the drug confers neuroprotection during cuprizone-induced demyelination, while 1 mg/kg aggravates the demyelination process.”

http://www.ncbi.nlm.nih.gov/pubmed/26842941

Cannabinoid receptors and their role in neuroprotection.

“Evidence has accumulated over the last few years suggesting that endocannabinoid-based drugs may potentially be useful to reduce the effects of neurodegeneration. In fact, exogenous and endogenous cannabinoids were shown to exert neuroprotection in a variety of in vitro and in vivo models of neuronal injury via different mechanisms,”

http://www.ncbi.nlm.nih.gov/pubmed/16052037

The endocannabinoid system as a target for the treatment of neuronal damage.

“Cannabinoids have been proposed as clinically promising neuroprotective molecules, based on their capability to normalize glutamate homeostasis, reducing excitotoxicity, to inhibit calcium influx, lowering intracellular levels and the subsequent activation of calcium-dependent destructive pathways, and to reduce the generation of reactive oxygen intermediates or to limit their toxicity, decreasing oxidative injury.

Cannabinoids are also able to decrease local inflammatory events by acting on glial processes that regulate neuronal survival, and to restore blood supply by reducing vasocontriction produced by several endothelium-derived factors.

Treatment of neurodegenerative disorders is a challenge for neuroscientists and neurologists. Unhappily, the efficacy of available medicines is still poor and there is an urgent need for novel neuroprotective agents. Cannabinoids can serve this purpose given their recognized antiexcitotoxic, antioxidant and anti-inflammatory properties.”

http://www.ncbi.nlm.nih.gov/pubmed/20230193