Tag Archives: endocannabinoids

Endocannabinoids and the gastrointestinal tract.

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“In the past centuries, different preparations of marijuana have been used for the treatment of gastrointestinal (GI) disorders, such as GI pain, gastroenteritis and diarrhea.

 Delta9-tetrahydrocannabinol (THC; the active component of marijuana), as well as endogenous and synthetic cannabinoids, exert their biological functions on the gastrointestinal tract by activating two types of cannabinoid receptors, cannabinoid type 1 receptor (CB1 receptor) and cannabinoid type 2 receptor (CB2 receptor). While CB1 receptors are located in the enteric nervous system and in sensory terminals of vagal and spinal neurons and regulate neurotransmitter release, CB2 receptors are mostly distributed in the immune system, with a role presently still difficult to establish.

Under pathophysiological conditions, the endocannabinoid system conveys protection to the GI tract, eg from inflammation and abnormally high gastric and enteric secretion.

 For such protective activities, the endocannabinoid system may represent a new promising therapeutic target against different GI disorders, including frankly inflammatory bowel diseases (eg, Crohn’s disease), functional bowel diseases (eg, irritable bowel syndrome), and secretion- and motility-related disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/16751708

The endocannabinoid system in the physiology and pathophysiology of the gastrointestinal tract.

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“Numerous investigations have recently demonstrated the important roles of the endocannabinoid system in the gastrointestinal (GI) tract under physiological and pathophysiological conditions.

 In the GI tract, cannabinoid type 1 (CB1) receptors are present in neurons of the enteric nervous system and in sensory terminals of vagal and spinal neurons, while cannabinoid type 2 receptors are located in immune cells. Activation of CB1 receptors was shown to modulate several functions in the GI tract, including gastric secretion, gastric emptying and intestinal motility.

Under pathophysiological conditions induced experimentally in rodents, the endocannabinoid system conveys protection to the GI tract (e.g. from inflammation and abnormally high gastric and enteric secretions).

Such protective activities are largely in agreement with anecdotal reports from folk medicine on the use of Cannabis sativa extracts by subjects suffering from various GI disorders.

 Thus, the endocannabinoid system may serve as a potentially promising therapeutic target against different GI disorders, including frankly inflammatory bowel diseases (e.g. Crohn’s disease), functional bowel diseases (e.g. irritable bowel syndrome) and secretion- and motility-related disorders.

As stimulation of this modulatory system by CB1 receptor agonists can lead to unwanted psychotropic side effects, an alternative and promising avenue for therapeutic applications resides in the treatment with CB1 receptor agonists that are unable to cross the blood-brain barrier, or with compounds that inhibit the degradation of endogenous ligands (endocannabinoids) of CB1 receptors, hence prolonging the activity of the endocannabinoid system.”

http://www.ncbi.nlm.nih.gov/pubmed/16133420

Cannabidiol, a constituent of Cannabis sativa, modulates sleep in rats.

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“Delta(9)-tetrahydrocannabinol (Delta(9)-THC) and cannabidiol (CBD) are two major constituents of Cannabis sativa. Delta(9)-THC modulates sleep, but no clear evidence on the role of CBD is available.

In order to determine the effects of CBD on sleep, it was administered intracerebroventricular (icv) in a dose of 10 microg/5 microl at the beginning of either the lights-on or the lights-off period. We found that CBD administered during the lights-on period increased wakefulness (W) and decreased rapid eye movement sleep (REMS). No changes on sleep were observed during the dark phase. Icv injections of CBD (10 microg/5microl) induced an enhancement of c-Fos expression in waking-related brain areas such as hypothalamus and dorsal raphe nucleus (DRD). Microdialysis in unanesthetized rats was carried out to characterize the effects of icv administration of CBD (10 microg/5 microl) on extracellular levels of dopamine (DA) within the nucleus accumbens. CBD induced an increase in DA release. Finally, in order to test if the waking properties of CBD could be blocked by the sleep-inducing endocannabinoid anandamide (ANA), animals received ANA (10 microg/2.5 microl, icv) followed 15 min later by CBD (10 microg/2.5 microl). Results showed that the waking properties of CBD were not blocked by ANA.

 In conclusion, we found that CBD modulates waking via activation of neurons in the hypothalamus and DRD. Both regions are apparently involved in the generation of alertness. Also, CBD increases DA levels as measured by microdialysis and HPLC procedures.

Since CBD induces alertness, it might be of therapeutic value in sleep disorders such as excessive somnolence.”

http://www.ncbi.nlm.nih.gov/pubmed/16844117

[The modulatory role of endocannabinoids in sleep].

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“The endogenous cannabinoid, or endocannabinoid, system is present in the central nervous system (CNS) of rodents and humans. This system includes receptors, endogenous ligands and enzymes. The presence of cannabinoid receptors, called CB1, in the CNS has been reported in the cerebral cortex, the hippocampus, the cerebellum and the brain stem. This neuroanatomical location suggests that this receptor could modify several physiological functions, such as the consolidation of memory, motor control and the generation of sleep.

 

Recent reports have described the presence of lipids in the CNS that bind to the CB1 receptor. Administration of said molecules induces cannabimimetic effects, and hence it has been suggested that these lipids are endogenous cannabinoids or endocannabinoids. Anandamide, 2-arachidonylglycerol, virodhamine, noladin ether and N-arachidonyldopamine are molecules that belong to the endocannabinoid family. Anandamide has received more attention from researchers because it was the first endocannabinoid to be reported. Pharmacological experiments have shown that this endocannabinoid induces several different intracellular and behavioural changes.

CONCLUSIONS:

In this study, we review the most important pharmacological aspects of exogenous cannabinoids and the neurobiological role played by the endocannabinoid system, including endogenous and exogenous ligands and receptors. We also examine their pharmacological effects on different behaviours, with particular attention given to the modulation of sleep.”

http://www.ncbi.nlm.nih.gov/pubmed/18297624

The role of the CB1 receptor in the regulation of sleep.

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“During the 1990s, transmembranal proteins in the central nervous system (CNS) that recognize the principal compound of marijuana, the delta-9-tetrahydrocannabinol (Delta9-THC) were described. The receptors were classified as central or peripheral, CB1 and CB2, respectively. To this date, it has been documented the presence in the CNS of specific lipids that bind naturally to the CB1/CB2 receptors.

The family of endogenous cannabinoids or endocannabinoids comprises oleamide, arachidonoylethanolamine, 2-arachidonylglycerol, virodhamine, noladin ether and N-arachidonyldopamine. Pharmacological experiments have shown that those compounds induce cannabimimetic effects. Endocannabinoids are fatty acid derivates that have a variety of biological actions, most notably via activation of the cannabinoid receptors. The endocannabinoids have an active role modulating diverse neurobiological functions, such as learning and memory, feeding, pain perception and sleep generation.

Experimental evidence shows that the administration of Delta9-THC promotes sleep.

 The activation of the CB1 receptor leads to an induction of sleep, this effect is blocked via the selective antagonist.

Since the system of the endogenous cannabinoids is present in several species, including humans, this leads to the speculation of the neurobiological role of the endocannabinoid system on diverse functions such as sleep modulation.

This review discusses the evidence of the system of the endocannabinoids as well as their physiological role in diverse behaviours, including the modulation of sleep.”

http://www.ncbi.nlm.nih.gov/pubmed/18514375

Functional role for cannabinoids in respiratory stability during sleep.

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“Serotonin, acting in the peripheral nervous system, can exacerbate sleep-related apnea, and systemically administered serotonin antagonists reduce sleep-disordered respiration in rats and bulldogs. Because cannabinoid receptor agonists are known to inhibit the excitatory effects of serotonin on nodose ganglion cells, we examined the effects of endogenous (oleamide) and exogenous (delta9-tetrahydrocannabinol; delta9THC) cannabimimetic agents on sleep-related apnea…

Our data show that delta9THC and oleamide each stabilized respiration during all sleep stages… This observation suggests an important role for endocannabinoids in maintaining autonomic stability during sleep…

CONCLUSIONS:

This study demonstrates potent suppression of sleep-related apnea by both exogenous and endogenous cannabinoids. These findings are of relevance to the pathogenesis and pharmacological treatment of sleep-related breathing disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/12071539

Circulating endocannabinoids and N-acyl-ethanolamides in patients with sleep apnea–specific role of oleoylethanolamide.

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“OBJECTIVE:  The endocannabinoid system promotes diverse effects on fat and glucose metabolism as well as on energy balance and sleep regulation. The role of N-acylethanolamides like oleoylethanolamide (OEA) and other endocannabinoids such as anandamide (AEA) and 2-arachidonyl-glycerol (2-AG) has not yet been investigated in patients with sleep apnea.

 

CONCLUSIONS: These results indicate that among the three analyzed fatty acid derivatives, OEA plays a specific role in patients with sleep apnea. Together with animal data, the 2-fold elevation of OEA serum concentrations could be interpreted as a neuroprotective mechanism against chronic oxidative stressors and a mechanism to promote wakefulness in patients with nocturnal sleep deprivation and daytime hypersomnolence.”

http://www.ncbi.nlm.nih.gov/pubmed/20429051

 

The endocannabinoid system is dysregulated in multiple sclerosis and in experimental autoimmune encephalomyelitis

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“The ability of cannabinoids to modulate both inflammatory and degenerative neuronal damage prompted investigations on the potential benefits of such compounds in multiple sclerosis (MS) and in animal models of this disorder. Here we measured endocannabinoid levels, metabolism and binding, and physiological activities in 26 patients with MS (17 females, aged 19–43 years), 25 healthy controls and in mice with experimental autoimmune encephalomyelitis (EAE), a preclinical model of MS.

 Our results show that MS and EAE are associated with significant alterations of the endocannabinoid system. We found that anandamide (AEA), but not 2-arachidonoylglycerol (2-AG), was increased in the CSF of relapsing MS patients. AEA concentrations were also higher in peripheral lymphocytes of these patients, an effect associated with increased synthesis and reduced degradation of this endocannabinoid. Increased synthesis, reduced degradation, and increased levels of AEA were also detected in the brains of EAE mice in the acute phase of the disease, possibly accounting for its anti-excitotoxic action in this disorder. Accordingly, neurophysiological recordings from single neurons confirmed that excitatory transmission in EAE slices is inhibited by CB1 receptor activation, while inhibitory transmission is not.

Our study suggests that targeting the endocannabinoid system might be useful for the treatment of MS.”

http://brain.oxfordjournals.org/content/130/10/2543.abstract

Israeli Study Finds Patients with Chronic Disease Benefit from Marijuana

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“A new study out of Israel looks to change that. Led by Zach Klein, a specialist in medical marijuana policy and the director of the documentary Prescribed Grass, researchers at Tel Aviv University tested medical marijuana on 19 nursing home residents. Patients were treated with cannabis in the form of powder, oil, vapor, or smoke three times daily over the course of a year.

 Seventeen of the 19 patients regained lost weight, and symptoms of pain, stiffness, tremors, insomnia, and PTSD decreased drastically. Their moods and communication skills also improved, and they had fewer nightmares and flashbacks, according to Klein.

“After I found this, everything has been better,” Moshe Rute, a Holocaust survivor stricken by nightmares and the effects of a stroke told the Times of Israel. “I’m still a Holocaust child, but I’m finally able to better cope.”

The 80-year-old Hadarim resident is one of 11,000 Israelis with permits from the government to use marijuana for medical purposes, a number that is growing rapidly.

“This is just the tip of the iceberg. It’s the future,” Klein said to the Times. “This is God’s doing, and it’s marvelous in our eyes.”

Perhaps as important as the improvement in pain management and quality of life was marijuana’s ability to replace some of the medication taken by the patients. By the end of the study, 72 percent were able to reduce the number of drugs they were taking daily. This includes medication for Parkinson’s disease, pain relievers, antipsychotics, and mood stabilizers, many of which can have debilitating and severe side effects.

“We know how to extend life, but sometimes it’s not pleasant and can cause a great deal of suffering, so we’re looking to alleviate this, to add quality to longevity,” head nurse Inbal Sikorin told the Times. “Cannabis meets this need. Almost all our patients are eating again, and their moods have improved tremendously.”

The country that discovered tetrahydrocannabinol (THC) the psychoactive ingredient in cannabis, in the 1960’s doesn’t have the stigma attached to marijuana that the United States does, as even senior rabbis have no qualms with its use or spread.

Klein is working on a new study at Israel’s Reuth Medical Center, in which he hopes to establish a connection between medical cannabis and improved swallowing. One of the biggest concerns with chronically ill patients is food intake, and Klein believes that cannabis, which can stimulate regions of the brain associated with swallowing reflexes, will have a positive impact.”

http://americannewsreport.com/nationalpainreport/israeli-study-finds-patients-with-chronic-disease-benefit-from-marijuana-8818444.html

Modulation of The Balance Between Cannabinoid CB1 and CB2 Receptor Activation During Cerebral Ischemic/Reperfusion Injury

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“A number of investigations have shown that CB2 receptor activation has anti-inflammatory therapeutic potential in various CNS diseases, such as multiple sclerosis, traumatic brain injury and Alzheimer’s disease. Because inflammatory responses have been shown to be important contributors to secondary injury following cerebral ischemia; the CB2 receptor has been investigated as a potential therapeutic target in stroke…

The most striking changes were obtained by combing a CB1 antagonist with a CB2 agonist. This combination elevated the cerebral blood flow during ischemia and reduced infarction by 75%…during cerebral ischemia/reperfusion injury, inhibition of CB1 receptor activation is protective while inhibition of CB2 receptor activation is detrimental.

 The greatest degree of neuroprotection was obtained by combining an inhibitor of CB1 activation with an exogenous CB2 agonist.

In conclusion, the results of this investigation demonstrate dynamic changes in the expression of CB1 and CB2 receptors during cerebral ischemic/reperfusion injury in mice. The effects of stimulation of these receptors on damage ischemia/reperfusion injury differed dramatically. Stimulation of the CB2 receptor was found to be neuroprotective, while inhibition of the CB1 receptor was also protective,too. The combination of a CB2 agonist and a CB1 antagonist provided the greatest degree of protection and indicated a synergistic effect derived from combining these agents. Therefore, changing the balance of stimulation of these receptors by endogenous cannabinoids may provide an important therapeutic strategy during stroke.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2577828/