Targeting the endocannabinoid system with cannabinoid receptor agonists: pharmacological strategies and therapeutic possibilities.

Philosophical Transactions of the Royal Society B: Biological Sciences: 367 (1607)

“Human tissues express cannabinoid CB(1) and CB(2) receptors that can be activated by endogenously released ‘endocannabinoids’ or exogenously administered compounds in a manner that reduces the symptoms or opposes the underlying causes of several disorders in need of effective therapy. Three medicines that activate cannabinoid CB(1)/CB(2) receptors are now in the clinic: Cesamet (nabilone), Marinol (dronabinol; Δ(9)-tetrahydrocannabinol (Δ(9)-THC)) and Sativex (Δ(9)-THC with cannabidiol). These can be prescribed for the amelioration of chemotherapy-induced nausea and vomiting (Cesamet and Marinol), stimulation of appetite (Marinol) and symptomatic relief of cancer pain and/or management of neuropathic pain and spasticity in adults with multiple sclerosis (Sativex). This review mentions several possible additional therapeutic targets for cannabinoid receptor agonists. These include other kinds of pain, epilepsy, anxiety, depression, Parkinson’s and Huntington’s diseases, amyotrophic lateral sclerosis, stroke, cancer, drug dependence, glaucoma, autoimmune uveitis, osteoporosis, sepsis, and hepatic, renal, intestinal and cardiovascular disorders. It also describes potential strategies for improving the efficacy and/or benefit-to-risk ratio of these agonists in the clinic. These are strategies that involve (i) targeting cannabinoid receptors located outside the blood-brain barrier, (ii) targeting cannabinoid receptors expressed by a particular tissue, (iii) targeting upregulated cannabinoid receptors, (iv) selectively targeting cannabinoid CB(2) receptors, and/or (v) adjunctive ‘multi-targeting’.”  https://www.ncbi.nlm.nih.gov/pubmed/23108552

“Targeting the endocannabinoid system with cannabinoid receptor agonists: pharmacological strategies and therapeutic possibilities”  http://rstb.royalsocietypublishing.org/content/367/1607/3353.long

Cannabinoid receptor signalling in neurodegenerative diseases: a potential role for membrane fluidity disturbance

Abstract

“Type-1 cannabinoid receptor (CB1) is the most abundant G-protein-coupled receptor (GPCR) in the brain. CB1 and its endogenous agonists, the so-called ‘endocannabinoids (eCBs)’, belong to an ancient neurosignalling system that plays important functions in neurodegenerative and neuroinflammatory disorders like Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis and multiple sclerosis. For this reason, research on the therapeutic potential of drugs modulating the endogenous tone of eCBs is very intense. Several GPCRs reside within subdomains of the plasma membranes that contain high concentrations of cholesterol: the lipid rafts. Here, the hypothesis that changes in membrane fluidity alter function of the endocannabinoid system, as well as progression of particular neurodegenerative diseases, is described. To this end, the impact of membrane cholesterol on membrane properties and hence on neurodegenerative diseases, as well as on CB1 signalling in vitro and on CB1-dependent neurotransmission within the striatum, is discussed. Overall, present evidence points to the membrane environment as a critical regulator of signal transduction triggered by CB1, and calls for further studies aimed at better clarifying the contribution of membrane lipids to eCBs signalling. The results of these investigations might be exploited also for the development of novel therapeutics able to combat disorders associated with abnormal activity of CB1.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3165948/

Role of CB1 cannabinoid receptors on GABAergic neurons in brain aging

“Brain aging is associated with cognitive decline that is accompanied by progressive neuroinflammatory changes. The endocannabinoid system (ECS) is involved in the regulation of glial activity and influences the progression of age-related learning and memory deficits.

Mice lacking the Cnr1 gene (Cnr1−/−), which encodes the cannabinoid receptor 1 (CB1), showed an accelerated age-dependent deficit in spatial learning accompanied by a loss of principal neurons in the hippocampus. The age-dependent decrease in neuronal numbers in Cnr1−/− mice was not related to decreased neurogenesis or to epileptic seizures. However, enhanced neuroinflammation characterized by an increased density of astrocytes and activated microglia as well as an enhanced expression of the inflammatory cytokine IL-6 during aging was present in the hippocampus of Cnr1−/− mice. The ongoing process of pyramidal cell degeneration and neuroinflammation can exacerbate each other and both contribute to the cognitive deficits. Deletion of CB1 receptors from the forebrain GABAergic, but not from the glutamatergic neurons, led to a similar neuronal loss and increased neuroinflammation in the hippocampus as observed in animals lacking CB1 receptors in all cells.

Our results suggest that CB1 receptor activity on hippocampal GABAergic neurons protects against age-dependent cognitive decline by reducing pyramidal cell degeneration and neuroinflammation.”

Cannabinoids as Therapeutic Agents for Ablating Neuroinflammatory Disease

“Cannabinoids have been reported to alter the activities of immune cells in vitro and in vivo. These compounds may serve as ideal agents for adjunct treatment of pathological processes that have a neuroinflammatory component. As highly lipophilic molecules, they readily access the brain. Furthermore, they have relatively low toxicity and can be engineered to selectively target cannabinoid receptors. To date, two cannabinoid receptors have been identified, characterized and designated CB1 and CB2. CB1 appears to be constitutively expressed within the CNS while CB2 apparently is induced during inflammation. The inducible nature of CB2 extends to microglia, the resident macrophages of the brain that play a critical role during early stages of inflammation in that compartment. Thus, the cannabinoid-cannabinoid receptor system may prove therapeutically manageable in ablating neuropathogenic disorders such as Alzheimer’s disease, multiple sclerosis, amyotrophic.”

“The marijuana plant, Cannabis sativa, has been consumed therapeutically and recreationally for centuries because of its medicinal and psychotropic attributes. Cannabis contains a complex array of substances, including a group of terpenoid-like, highly lipophilic compounds referred to as cannabinoids. To date, over 60 cannabinoids have been identified from the marijuana plant. Cannabinoids account for the majority of the effects attributed to marijuana that users experience, including euphoria, impaired perception and memory, and mild sedation. While cannabinoids have been used to abolish loss of appetite and to ablate nausea and pain in patients suffering from severe medical disorders, these compounds also possess immune modulatory properties that may prove detrimental to human health. However, accumulating evidence suggests that cannabinoids also may serve as therapeutic agents in neuropathogenic diseases, pathologically hallmarked by elicitation of pro-inflammatory factors by cells of the central nervous system (CNS) and infiltrated peripheral immunocytes. Cannabinoids have the potential to be ideal therapeutic candidates in abolishing inflammatory neuropathies in that they can readily penetrate the blood brain barrier (BBB) to access the brain, have low levels of toxicity, and can specifically exert their effects through cannabinoid receptors. The major cannabinoid receptor type that appears to be targeted in neuroinflammation is cannabinoid receptor 2 (CB2). This receptor has been identified in select cells of the CNS, can be induced on demand during early inflammatory events, and has been shown to attenuate pro-inflammatory cytokine production by microglia, the resident macrophages of the brain that play a central role in many neuropathological processes.”

“In the present review the immune modulatory properties of cannabinoids, including their relation to interaction with cannabinoid receptors as linked to inflammatory neuropathies will be discussed. Included in this review will be an overview of the signal transduction cascades associated with cannabinoid receptors, and the effects of cannabinoid receptor signaling on immune cell function and immunity, and more importantly in the CNS. These discussions will lay the groundwork for the critical element of this review, in which we explore the potential of cannabinoid receptors to serve as therapeutic targets to attenuate the elicitation of pro-inflammatory mediators during neuropathogenic diseases and disorders such as Alzheimer’s disease (AD), Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS), HIV Encephalitis (HIVE), Closed Head Injury (CHI) and Granulomatous Amebic Encephalitis (GAE).”

“It is apparent that therapeutic intervention at an early stage of neuroinflammation is critical. The recognition that microglia express CB2 and that its activation results in ablation of untoward immune responses indicates that this receptor may serve as an ideal therapeutic target. Cannabinoids, as highly lipophilic compounds, can readily penetrate the BBB and access the brain. Furthermore, these compounds can be designed to have low toxicity, minimal psychotropic properties, and to selectively target cells that express the CB2, particularly microglia that serve as endogenous immune cells of the CNS and that play a prominent role in neuroinflammatory processes.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2750822/

Can the benefits of cannabinoid receptor stimulation on neuroinflammation, neurogenesis and memory during normal aging be useful in AD prevention?

Abstract

“Background

Alzheimer’s disease has become a growing socio-economical concern in developing countries where increased life expectancy is leading to large aged populations. While curing Alzheimer’s disease or stopping its progression does not appear within reach in a foreseeable future, new therapies capable of delaying the pathogenesis would represent major breakthroughs.

Presentation of the hypothesis

The growing number of medical benefits of cannabinoids, such as their ability to regulate age-related processes like neuroinflammation, neurogenesis and memory, raise the question of their potential role as a preventive treatment of AD.

Testing the hypothesis

To test this hypothesis, epidemiological studies on long term, chronic cannabinoid users could enlighten us on the potential benefits of these compounds in normal and pathological ageing processes. Systematic pharmacological (and thus more mechanistic) investigations using animal models of Alzheimer’s disease that have been developed would also allow a thorough investigation of the benefits of cannabinoid pharmacotherapy in the pathogenesis of Alzheimer’s disease.

Implications of the hypothesis

The chronic administration of non-selective cannabinoids may delay the onset of cognitive deficits in AD patients; this will dramatically reduce the socio-economic burden of AD and improve the quality of life of the patients and their families.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3284401/

Anti-inflammatory property of the cannabinoid agonist WIN-55212-2 in a rodent model of chronic brain inflammation

“Cannabinoid receptors (CBr) stimulation induces numerous central and peripheral effects. A growing interest in the beneficial properties of manipulating the endocannabinoid system has lead to the possible involvement of CBr in the control of brain inflammation… Our results emphasize the potential use of CBr agonists in the regulation of inflammatory processes within the brain; this knowledge may lead to the use of CBr agonists in the treatment of neurodegenerative diseases associated with chronic neuroinflammation, such as Alzheimer disease.”

“The current report is the first to our knowledge to demonstrate the modulatory role of cannabinoids in an animal model of chronic neuroinflammation, pointing out the effectiveness of a CBr agonist on the consequences of LPS mediated neuroinflammation at a dose (0.5 mg/kg/day i.p. of WIN-55212-2) that does not impair performance in a patial memory task. These results further advocate for the manipulation of the endocannabinoid system to diminish the consequences of neuroinflammation in progression of AD and others inflammation-related diseases.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1852513/

Cannabinoid receptors and endocannabinoids: role in neuroinflammatory and neurodegenerative disorders.

Abstract

“The G-protein coupled receptors for Δ⁹-tetrahydrocannabinol, the major psychoactive principle of marijuana, are known as cannabinoid receptors of type 1 (CB₁) and 2 (CB₂) and play important functions in degenerative and inflammatory disorders of the central nervous system. Whilst CB₁ receptors are mostly expressed in neurons, where they regulate neurotransmitter release and synaptic strength, CB₂ receptors are found mostly in glial cells and microglia, which become activated and over-express these receptors during disorders such as Alzheimer’s disease, multiple sclerosis, amyotropic lateral sclerosis, Parkinson’s disease, and Huntington’s chorea. The neuromodulatory actions at CB₁ receptors by endogenous agonists (‘endocannabinoids’), of which anandamide and 2-arachidonoylglycerol are the two most studied representatives, allows them to counteract the neurochemical unbalances arising during these disorders. In contrast, the immunomodulatory effects of these lipophilic mediators at CB₂ receptors regulate the activity and function of glia and microglia. Indeed, the level of expression of CB₁ and CB₂ receptors or of enzymes controlling endocannabinoid levels, and hence the concentrations of endocannabinoids, undergo time- and brain region-specific changes during neurodegenerative and neuroinflammatory disorders, with the initial attempt to counteract excitotoxicity and inflammation. Here we discuss this plasticity of the endocannabinoid system during the aforementioned central nervous system disorders, as well as its dysregulation, both of which have opened the way to the use of either direct and indirect activators or blockers of CB₁ and CB₂ receptors for the treatment of the symptoms or progression of these diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/20632970

Inflammation and aging: can endocannabinoids help?

“Aging often leads to cognitive decline due to neurodegenerative process in the brain. As people live longer, a growing concern exist linked to long-term, slowly debilitating diseases that have not yet found a cure, such as Alzheimer’s disease. Recently, the role of neuroinflammation has attracted attention due to its slow onset, chronic nature and its possible role in the development of many different neurodegenerative diseases. In the future, treatment of chronic neuroinflammation may help counteract aspects of neurodegenerative disease. Our recent studies have focused upon the endocannabinoid system for its unique effects on the expression of neuroinflammation. The basis for the manipulation of the endocannabinoid system in the brain in combination with existing treatments for Alzheimer’s disease will be discussed in this review.”

“Endocannabinoids

Cannabinoid refers to naturally occurring or synthetic molecules mimicking the activity of plant-derived cannabinoids from Cannabis Sativa. Two types of cannabinoid receptors have been so far identified in the body, named CB1 and CB2. Discovery of cannabinoid receptors (CBr) lead to the finding of endogenous agonists for these receptors called endocannabinoids (EC). EC are derived from arachidonic acid, arachidonoylethanolamide (anandamide), and 2-arachidonoyl glycerol (2-AG), synthesized on-demand post-synaptically and released in response to the entry of calcium ions. These EC in combination with the two known CBr constitute the endocannabinoid system (ECS). In the central nervous system (CNS), CB1 is overwhelmingly represented over CB2 and particularly abundant in cortical regions, the hippocampus, cerebellum and basal ganglia while CB2 may be restricted to microglia or neurons in the brainstem  and cerebellum. Deactivation of the EC is due to a rapid enzymatic degradation in the synaptic cleft or after membrane transport. The ECS is thought to be a neuromodulator and an immunomodulator. In the CNS, the ECS can influence food intake, endocrine release, motor control, cognitive processes, emotions and perception. Cannabinoids treatment has been shown to be neuroprotective under many experimental conditions. Drugs that manipulate the ECS are currently evaluated in various diseases ranging from cancer to AIDS for their peripheral analgesic and immunosuppressive properties. Their anti-inflammatory actions may make them useful in the treatment of multiple sclerosis, Parkinson’s disease and AD. Very little in vivo evidence to support the use of EC receptor agonists has been reported, although in vitro studies have found evidence for their anti-inflammatory effectiveness. Our recent work demonstrated the anti-inflammatory effect of a chronic treatment of a low dose of the CBr agonist WIN-55,212-2 (without psychoactive effects) on the consequences of chronic neuroinflammation induced by the infusion of LPS into the 4th ventricle of young rats. Moreover, that same anti-inflammatory effect was found using a non-psychoactive dose given by slow subcutaneous infusion of WIN-55,212-2 to healthy aged rats; these rats also demonstrated improved spatial memory. Our ongoing work in aged rats has shown that treatment with the CBr agonist WIN-55,212-2 increases neurogenesis in the hippocampus. Our preliminary data suggest that the neurogenic and anti-inflammatory effects in aged rats are due to the agonist/antagonist properties of WIN-55,212-2 at multiple receptors.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2408719/

How Cannabinoids May Slow Brain Aging

Stoners aren’t known for their memory prowess but a new review suggests that drugs similar to marijuana’s active ingredients may hold promise for preventing— or even reversing— brain aging and possibly Alzheimer‘s and other degenerative brain diseases.

Read more: http://healthland.time.com/2012/10/29/how-cannabinoids-may-slow-brain-aging/#ixzz2AjCxutuI

Major Health Benefits of Medical Cannabis

“The benefits of medical marijuana plant are extensive, pervasive, and long-standing. Because of the way the cannabis impacts the Autonomic Nervous System which develops the breath and relaxes the body, prospective for health and curative characteristics are huge. Some of the major health benefits of medical cannabis are explained below:

Treats Migraines

Cannabis healing has been very effective in the treatment of migraine headaches. Migraine headaches are vascular in source and are often preceded by an air characterized by nausea, flashes of light, faintness or photosensitivity.

Slows Down Tumor Growth

Studies have shown that cannabis help in slow down the facsimile and slow down the production of cancer cells in body. It is also a natural antiemetic, which makes it effectual in plummeting the nausea and vomiting related with chemo and radiation therapies. So taking marijuana slows down the tumor growth too.

Relieves Symptoms of Chronic Diseases

Marijuana is one of the best natural pain relievers that can help sufferers of chronic pain live more relaxed lives. The side effects are often much less severe than the other common pain medications.

Prevents Alzheimer’s

Cannabis reduces the occurrence of depression in Alzheimer’s patients, which can help patients to keep up a higher level of brain function. That is a powerful way to keep patients performance for a longer time after the first onset of Alzheimer’s disease.

Treats Glaucoma

Some strains of this medicinal plant have been shown that, they are potentially decreasing the force that glaucoma can place on the optic nerve; thereby the patients can easily cut the critical condition by smoking or taking the marijuana edibles or medicines.

Prevents Seizures

Seizure is a kind of epilepsy which almost affects more than 2 millions of Americans and 30 millions of people worldwide. Epilepsy is a condition when some of the brain cells become abnormally excitable. People using marijuana to control epilepsy should be alert when there is any removal of any tablets which controls seizures may leave you more susceptible to the patient. Marijuana is no exception. Patients with epilepsy are advised to exercise caution when using oral THC because there is no enough sufficient knowledge about the convulsive or anti-convulsive properties of the single compound.

For ADD and ADHD

Many people who endure with ADD and/or ADHD find that medical cannabis recovers their knack to hub and their level of recital with definite tasks. There are no clinical studies on humans but there are some beginner studies have done on animals that point to less hyperactivity and impulsivity with the use of cannabinoids (the active medicines in cannabis).

Relieve PMS

Millions of women have an illness on Premenstrual Syndrome (PMS). PMS includes the symptoms of headaches, abdominal cramps, bloating and fluid retention. Many women report that they have tried several different medications but none as give any significant relief like Medical Marijuana. Cannabis medicine has shown to give symptomatic relief from all the unpleasant symptoms of PMS.

Calm Those With Tourette’s and OCD

Several psychological disorders have been known to be related with the medical benefits of marijuana as well. Taking weed of prescribed amount on regular basis can slow down the tics for those who are suffering from Tourette’s syndrome and Obsessive Compulsive Disorder (OCD). Yes some of the qualities in marijuana plant help the patient to calm themselves when any creation of intrusive thoughts which produces fear, uneasiness and abnormal behaviors.”

http://www.herbalmission.org/major-health-benefits-of-medical-cannabis.php