Monthly Archives: January 2017

Cannabinoids in the treatment of glaucoma.

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“The leading cause of irreversible blindness is glaucoma, a disease normally characterized by the development of ocular hypertension and consequent damage to the optic nerve at its point of retinal attachment. This results in a narrowing of the visual field, and eventually results in blindness.

A number of drugs are available to lower intraocular pressure (IOP), but, occasionally, they are ineffective or have intolerable side-effects for some patients and can lose efficacy with chronic administration.

The smoking of marijuana has decreased IOP in glaucoma patients. Cannabinoid drugs, therefore, are thought to have significant potential for pharmaceutical development.

The discovery of ocular cannabinoid receptors implied an explanation for the induction of hypotension by topical cannabinoid applications, and has stimulated a new phase of ophthalmic cannabinoid research.

Featured within these investigations is the possibility that at least some cannabinoids may ameliorate optic neuronal damage through suppression of N-methyl-D-aspartate receptor hyperexcitability, stimulation of neural microcirculation, and the suppression of both apoptosis and damaging free radical reactions, among other mechanisms.

Separation of therapeutic actions from side-effects now seems possible through a diverse array of novel chemical, pharmacological, and formulation strategies.”

 https://www.ncbi.nlm.nih.gov/pubmed/12182967

The gastrointestinal tract – a central organ of cannabinoid signaling in health and disease

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“In ancient medicine, extracts of the marijuana plant Cannabis sativa were used against diseases of the gastrointestinal (GI) tract.

Today, our knowledge of the ingredients of the Cannabis plant has remarkably advanced enabling us to use a variety of herbal and synthetic cannabinoid (CB) compounds to study the endocannabinoid system (ECS), a physiologic entity that controls tissue homeostasis with the help of endogenously produced CBs and their receptors.

After many anecdotal reports suggested beneficial effects of Cannabis in GI disorders, it was not surprising to discover that the GI tract accommodates and expresses all the components of the ECS.

The following review summarizes important and recent findings on the role of CB receptors and their ligands in the GI tract with emphasis on GI disorders, such as irritable bowel syndrome, inflammatory bowel disease, and colon cancer.”

https://www.ncbi.nlm.nih.gov/pubmed/27561826

[Cannabinoid applications in glaucoma].

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“Glaucoma is a slowly progressive optic neuropathy that is one of the leading causes of legal blindness throughout the world.

Currently there is a limited group of topical drugs for the medical treatment of glaucoma is currently limited, and research needs to be focused on new therapeutic horizons, such as the potential usefulness of the cannabinoid agonists for the treatment of glaucoma.

To review the current scientific literature related to the beneficial effects derived from the different ways of administration of cannabinoids indicated for the glaucomatous optic neuropathy.

Cannabinoid receptors have shown an intense expression in ocular tissues implicated in the regulation of the intraocular pressure, as well as inner layers of the retina. Through activation of CB1 and CB1 specific receptors and through other still unknown pathways, the cannabinoid agonists have shown both a clear hypotensive, as well as an experimentally proved neuroprotective effect on retinal ganglion cells.

CONCLUSIONS:

Some cannabinoid agonists (WIN 55212-2, anandamide) have demonstrated, in experimental studies, to act as «ideal drugs» in the management of glaucoma, as they have been shown to have good tolerability after topical application, efficiently reduce intraocular pressure, and behave as neuroprotectors on retinal ganglion cells.”

https://www.ncbi.nlm.nih.gov/pubmed/21414525

Neural contractions in colonic strips from patients with diverticular disease: role of endocannabinoids and substance P

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“Diverticulosis is a common disease of not completely defined pathogenesis. Motor abnormalities of the intestinal wall have been frequently described but very little is known about their mechanisms. We investigated in vitro the neural response of colonic longitudinal muscle strips from patients undergoing surgery for complicated diverticular disease (diverticulitis).

Neural control of colon motility is profoundly altered in patients with diverticulitis. Their raised levels of anandamide, apparent desensitisation of the presynaptic neural cannabinoid CB1 receptor, and the SR141716 induced intrinsic response, suggest that endocannabinoids may be involved in the pathophysiology of complications of colonic diverticular disease.

Agents acting on the endocannabinoid system could eventually find therapeutic application in colonic inflammatory and motility disorders.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1856307/

Neuroimmmune interactions of cannabinoids in neurogenesis: focus on interleukin-1β (IL-1β) signalling.

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Biochemical Society Transactions

“Neuroimmune networks and the brain endocannabinoid system contribute to the maintenance of neurogenesis.

Activation of cannabinoid receptors suppresses chronic inflammatory responses through the attenuation of pro-inflammatory mediators. Moreover, the endocannabinoid system directs cell fate specification of NSCs (neural stem cells) in the CNS (central nervous system).

The aim of our work is to understand better the relationship between the endocannabinoid and the IL-1β (interleukin-1β) associated signalling pathways and NSC biology, in order to develop therapeutical strategies on CNS diseases that may facilitate brain repair.

NSCs express functional CB1 and CB2 cannabinoid receptors, DAGLα (diacylglycerol lipase α) and the NSC markers SOX-2 and nestin. We have investigated the role of CB1 and CB2 cannabinoid receptors in the control of NSC proliferation and in the release of immunomodulators [IL-1β and IL-1Ra (IL-1 receptor antagonist)] that control NSC fate decisions. Pharmacological blockade of CB1 and/or CB2 cannabinoid receptors abolish or decrease NSC proliferation, indicating a critical role for both CB1 and CB2 receptors in the proliferation of NSC via IL-1 signalling pathways.

Thus the endocannabinoid system, which has neuroprotective and immunomodulatory actions mediated by IL-1 signalling cascades in the brain, could assist the process of proliferation and differentiation of embryonic or adult NSCs, and this may be of therapeutic interest in the emerging field of brain repair.

In summary, cannabinoids and IL-1β seem to play antagonistic roles in neurogenesis: although cannabinoids increase proliferation and induce formation and maturation of new neurons, IL-1β blocks proliferation and formation of new neurons, inducing a shift towards a glial fate. This may be important in situations such as in aging, neurodegenerative diseases, and lesions of the brain and spinal cord.”

http://www.biochemsoctrans.org/content/41/6/1577.long

Diuretic effects of cannabinoid agonists in mice

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“Cannabinoids both increase urine output and decrease urinary frequency in human subjects. However, these effects have not been systematically evaluated in intact mice, a species commonly used to evaluate the effects of novel cannabinoids.

The present studies investigated whether cannabinoid agonists reliably produce diuresis in mice at doses comparable to those that produce other cannabinoid effects and, further, identified the receptors that may mediate these effects.

These findings suggest that mice may provide a model for understanding the mixed effects of marijuana on urine output, as described in clinical studies, and aid in the development of targeted cannabinoid based therapies for bladder dysfunction.

Clinical studies have reported beneficial effects of smoked or aerosolized cannabis on bladder dysfunction in patients with multiple sclerosis, primarily by decreasing urinary frequency in these subjects following marijuana use. These reports contrast with the earlier clinical reports demonstrating increase in urine output after cannabis administration.

Our findings in mice demonstrate a dose related increase or decrease in urine output, providing a platform for understanding the mixed effects on urine output observed with marijuana in various clinical studies. As noted earlier in a study with rats, the diuresis induced by THC in mice also is weakly naturetic compared to furosemide and further investigations in this area may yield a new, clinically beneficial diuretic.

In contrast, our data suggest that development of peripherally selective cannabinoid CB1 agonists may be beneficial for patients suffering from bladder dysfunction.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3872476/

Diuretic effects of cannabinoids.

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“These data indicate that cannabinoids have robust diuretic effects in rats that are mediated via CB1 receptor mechanisms.

Overall, our data indicate that diuresis is a CB1-mediated effect that may serve as a reliable and objective physiologic measure of cannabinoid action in rats; the circumstances under which these results represent a potential therapeutic benefit or potential liability of cannabinoids remain to be determined.

The implications of these findings currently are poorly understood, although a better understanding of mechanisms and sites of action by which cannabinoids increase urine loss may lead to the rational development of novel cannabinergic medications.”  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3533417/

“Diuretics are medicines that help reduce the amount of water in the body. Diuretics are used to treat the buildup of excess fluid in the body that occurs with some medical conditions such ascongestive heart failure, liver disease, and kidney disease. Some diuretics are also prescribed to treat high bloodpressure. These drugs act on the kidneys to increase urine output. This reduces the amount of fluid in the bloodstream,which in turn lowers blood pressure.” http://medical-dictionary.thefreedictionary.com/diuretics

Cannabinol and cannabidiol exert opposing effects on rat feeding patterns.

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“Increased food consumption following ∆(9)-tetrahydrocannabinol-induced cannabinoid type 1 receptor agonism is well documented.

However, possible non-∆(9)-tetrahydrocannabinol phytocannabinoid-induced feeding effects have yet to be fully investigated. Therefore, we have assessed the effects of the individual phytocannabinoids, cannabigerol, cannabidiol and cannabinol, upon feeding behaviors.

Cannabinol induced a CB(1)R-mediated increase in appetitive behaviors via significant reductions in the latency to feed and increases in consummatory behaviors via increases in meal 1 size and duration. Cannabinol also significantly increased the intake during hour 1 and total chow consumed during the test. Conversely, cannabidiol significantly reduced total chow consumption over the test period. Cannabigerol administration induced no changes to feeding behavior.

This is the first time cannabinol has been shown to increase feeding. Therefore, cannabinol could, in the future, provide an alternative to the currently used and psychotropic ∆(9)-tetrahydrocannabinol-based medicines since cannabinol is currently considered to be non-psychotropic.

Furthermore, cannabidiol reduced food intake in line with some existing reports, supporting the need for further mechanistic and behavioral work examining possible anti-obesity effects of cannabidiol.”

https://www.ncbi.nlm.nih.gov/pubmed/22543671

Tetrahydrocannabinol and endocannabinoids in feeding and appetite.

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“The physiological control of appetite and satiety, in which numerous neurotransmitters and neuropeptides play a role, is extremely complex. Here we describe the involvement of endocannabinoids in these processes.

These endogenous neuromodulators enhance appetite in animals.

The same effect is observed in animals and in humans with the psychotropic plant cannabinoid Delta(9)-tetrahydrocannabinol, which is an approved appetite-enhancing drug.

The CB(1) cannabinoid receptor antagonist SR141716A blocks the effects on feeding produced by the endocannabinoids. If administered to mice pups, this antagonist blocks suckling.

In obese humans, it causes weight reduction.

Very little is known about the physiological and biochemical mechanisms involved in the effects of Delta(9)-tetrahydrocannabinol and the cannabinoids in feeding and appetite.”

https://www.ncbi.nlm.nih.gov/pubmed/12182965

Cannabis sativa and the endogenous cannabinoid system: therapeutic potential for appetite regulation.

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“The herb Cannabis sativa (C. sativa) has been used in China and on the Indian subcontinent for thousands of years as a medicine.

However, since it was brought to the UK and then the rest of the western world in the late 19th century, its use has been a source of controversy. Indeed, its psychotropic side effects are well reported but only relatively recently has scientific endeavour begun to find valuable uses for either the whole plant or its individual components.

Here, we discuss evidence describing the endocannabinoid system, its endogenous and exogenous ligands and their varied effects on feeding cycles and meal patterns.

Furthermore we also critically consider the mounting evidence which suggests non-Δ(9) tetrahydrocannabinol phytocannabinoids play a vital role in C. sativa-induced feeding pattern changes.

Indeed, given the wide range of phytocannabinoids present in C. sativa and their equally wide range of intra-, inter- and extra-cellular mechanisms of action, we demonstrate that non-Δ(9) tetrahydrocannabinol phytocannabinoids retain an important and, as yet, untapped clinical potential.”

https://www.ncbi.nlm.nih.gov/pubmed/21213357