Latest advances in cannabinoid receptor agonists.

“Since the discovery of cannabinoid receptors and their endogenous ligands in early 1990s, the endocannabinoid system has been shown to play a vital role in several pathophysiological processes. It has been targeted for the treatment of several diseases including neurodegenerative diseases (Parkinson’s disease, Alzheimer’s disease, Huntington’s disease and MS), cancer, obesity, inflammatory bowel disease, neuropathic and inflammatory pain. The last decade has witnessed remarkable advances in the development of cannabinergic ligands displaying high selectivity and potency towards two subtypes of cannabinoid receptors, namely CB1 and CB2.”

 “…we highlight the latest advances made in the development of cannabinoid agonists and summarize recently disclosed, novel chemical scaffolds as CB-selective agonists…”

 

“CONCLUSIONS:

Our analysis reveals prolific patenting activity mainly in the CB2 selective agonist area. Limiting the BBB penetrability, thereby, leading to peripherally restricted CB1/CB2 agonists and enhancing CB2-selectivity emerge as likely prerequisites for avoidance of adverse central CB1 mediated side effects.”

http://www.ncbi.nlm.nih.gov/pubmed/19939187

From cannabis to the endocannabinoid system: refocussing attention on potential clinical benefits.

Image result for West Indian Med J

“Cannabis sativa is one of the oldest herbal remedies known to man. Over the past four thousand years, it has been used for the treatment of numerous diseases but due to its psychoactive properties, its current medicinal usage is highly restricted. In this review, we seek to highlight advances made over the last forty years in the understanding of the mechanisms responsible for the effects of cannabis on the human body and how these can potentially be utilized in clinical practice. During this time, the primary active ingredients in cannabis have been isolated, specific cannabinoid receptors have been discovered and at least five endogenous cannabinoid neurotransmitters (endocannabinoids) have been identified. Together, these form the framework of a complex endocannabinoid signalling system that has widespread distribution in the body and plays a role in regulating numerous physiological processes within the body. Cannabinoid ligands are therefore thought to display considerable therapeutic potential and the drive to develop compounds that can be targeted to specific neuronal systems at low enough doses so as to eliminate cognitive side effects remains the ‘holy grail’ of endocannabinoid research.”

http://www.ncbi.nlm.nih.gov/pubmed/23155985

FAAH and MAGL inhibitors: therapeutic opportunities from regulating endocannabinoid levels.

Abstract

 “Apart from their widespread recreational abuse, the psychoactive preparations of the plant Cannabis sativa and its major psychotropic component, Delta9-tetrahydrocannabinol (THC), are also known for their medicinal properties. Following the identification of receptors for THC – the cannabinoid CB1 and CB2 receptors – in mammals, various pharmaceutical strategies have attempted to exploit the properties of the cannabinoid system while minimizing psychotropic side effects. The cloning of the cannabinoid CB1 and CB2 receptors enabled the discovery of the endogenous agonists of the receptors, the endocannabinoids, and eventually led to the identification of enzymes that catalyze endocannabinoid inactivation. Unlike exogenously administered THC and synthetic CB1 and CB2 agonists, the endocannabinoids that are produced endogenously following the onset of several pathologies may act in a site- and time-specific manner to minimize the consequences of such conditions. This observation has suggested the possibility of targeting endocannabinoid-degrading enzymes to prolong the precisely regulated pro-homeostatic action of endocannabinoids. Two major enzymes have been cloned and investigated thoroughly: fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). Inhibitors of these enzymes have demonstrated therapeutic benefit in animal models of several disorders, including neuropathic pain, anxiety and inflammatory bowel diseases, as well as against the proliferation and migration of cancer cells. This review describes the major biochemical properties of FAAH and MAGL, and the design and pharmacological properties of inhibitors of these enzymes.”

http://www.ncbi.nlm.nih.gov/pubmed/20047159

Cannabidiol, extracted from Cannabis sativa, selectively inhibits inflammatory hypermotility in mice

 “Cannabidiol is a Cannabis-derived non-psychotropic compound that exerts a plethora of pharmacological actions, including anti-inflammatory, neuroprotective and antitumour effects, with potential therapeutic interest. However, the actions of cannabidiol in the digestive tract are largely unexplored. In the present study, we investigated the effect of cannabidiol on intestinal motility in normal (control) mice and in mice with intestinal inflammation.”

“Cannabidiol selectively reduces croton oil-induced hypermotility in mice in vivo and this effect involves cannabinoid CB1 receptors and FAAH. In view of its low toxicity in humans, cannabidiol may represent a good candidate to normalize motility in patients with inflammatory bowel disease.”

“The plant Cannabis sativa contains more than 60 terpenophenolic compounds, named phytocannabinoids. The best-studied phytocannabinoid is Δ9-tetrahydrocannabinol, which binds specific G-protein-coupled receptors, named cannabinoid (CB1 and CB2) receptors. The well-known psychotropic effects of Δ9-tetrahydrocannabinol, which are largely mediated by activation of brain cannabinoid CB1 receptors, have always raised a number of clinical and ethical problems. Therefore, a valid therapeutic alternative may be the use of non-psychotropic phytocannabinoids, including cannabidiol (CBD). CBD, unlike Δ9-tetrahydrocannabinol, has very low affinity for both cannabinoid CB1 and CB2 receptors, although it has been proposed that CBD may modulate endocannabinoid function through its ability to inhibit the hydrolysis of anandamide and to act as a transient receptor potential vanilloid 1 agonist. CBD is a major component of Sativex, a preparation of cannabinoids, which has been approved by Health Canada for the treatment of neuropathic pain in multiple sclerosis.”

“The pharmacological profile of CBD has been recently reviewed. Briefly stated, CBD has been shown to exert (1) antioxidant, neuroprotective and antiproliferative actions in cultured cells and (2) anti-anxiety, hypnotic, anticonvulsant, neuroprotective, antinausea, anti-ischaemic, anticancer and notably anti-inflammatory effects in rodents in vivo. The anti-inflammatory effects of CBD have been demonstrated in both acute and chronic experimental models of inflammation, that is, paw oedema and arthritis.”

“In conclusion, we have shown that the marijuana component CBD normalize intestinal motility in an experimental model of ileitis. In vitro results showed antispasmodic actions of CBD on intestinal ileal segments. The inhibitory effect of CBD involves, at least in vivo, cannabinoid CB1 receptors and FAAH. In view of its safety records in humans (an average daily dose of about 700 mg/day for 6 weeks was found to be non-toxic, relative to placebo, in clinical trials; and because CBD reduced motility during inflammation and not in physiological conditions, CBD might be considered as a good candidate to be clinically evaluated for the treatment of hypermotility associated with inflammatory bowel disease.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2451037/

Cannabinoids for the treatment of inflammation.

“Cannabinoids are effective at suppressing immune and inflammation functions in leukocytes in vitro, and in animal models of acute inflammation, such as the mouse hind paw, ear and air pouch models, as well as gastrointestinal, pulmonary, myocardial, vascular, periodontal, neural, hepatic, pancreatic and arthritic inflammation models.

The non-psychoactive cannabinoid receptor CB2 is emerging as a critical target for cannabinoid regulation of inflammation, and thus CB2-selective agonists are undergoing intense investigation and research. This review discusses the evidence for cannabinoid regulation of inflammation across a range of models and highlights the most promising drug candidates.”

http://www.ncbi.nlm.nih.gov/pubmed/17520866

Cannabinoid-based drugs as anti-inflammatory therapeutics.

“In the nineteenth century, marijuana was prescribed by physicians for maladies ranging from eating disorders to rabies. However, as newer, more effective drugs were discovered and as the potential for abuse of marijuana was recognized, its use as a therapeutic became restricted, and only recently has its therapeutic potential been re-evaluated.

 

 Recent studies in animal models and in humans have produced promising results for the treatment of various disorders – such as obesity, cancer, and spasticity and tremor due to neuropathology – with drugs based on marijuana-derived cannabinoids.

 

 Moreover, as I discuss here, a wealth of information also indicates that these drugs have immunosuppressive and anti-inflammatory properties; therefore, on the basis of this mode of action, the therapeutic usefulness of these drugs in chronic inflammatory diseases is now being reassessed.”

 

http://www.ncbi.nlm.nih.gov/pubmed/15864274

Cannabinoids as novel anti-inflammatory drugs

Figure 1

“Cannabinoids are a group of compounds that mediate their effects through cannabinoid receptors. The discovery of Δ9-tetrahydrocannabinol (THC) as the major psychoactive principle in marijuana, as well as the identification of cannabinoid receptors and their endogenous ligands, has led to a significant growth in research aimed at understanding the physiological functions of cannabinoids. Cannabinoid receptors include CB1, which is predominantly expressed in the brain, and CB2, which is primarily found on the cells of the immune system. The fact that both CB1 and CB2 receptors have been found on immune cells suggests that cannabinoids play an important role in the regulation of the immune system. Recent studies demonstrated that administration of THC into mice triggered marked apoptosis in T cells and dendritic cells, resulting in immunosuppression. In addition, several studies showed that cannabinoids downregulate cytokine and chemokine production and, in some models, upregulate T-regulatory cells (Tregs) as a mechanism to suppress inflammatory responses. The endocannabinoid system is also involved in immunoregulation. For example, administration of endocannabinoids or use of inhibitors of enzymes that break down the endocannabinoids, led to immunosuppression and recovery from immune-mediated injury to organs such as the liver. Manipulation of endocannabinoids and/or use of exogenous cannabinoids in vivo can constitute a potent treatment modality against inflammatory disorders. This review will focus on the potential use of cannabinoids as a new class of anti-inflammatory agents against a number of inflammatory and autoimmune diseases that are primarily triggered by activated T cells or other cellular immune components.”

“Cannabis, commonly known as marijuana, is a product of the Cannabis sativa plant and the active compounds from this plant are collectively referred to as cannabinoids. For several centuries, marijuana has been used as an alternative medicine in many cultures and, recently, its beneficial effects have been shown in: the treatment of nausea and vomiting associated with cancer chemotherapy; anorexia and cachexia seen in HIV/AIDS patients; and in neuropathic pain and spasticity in multiple sclerosis. Cannabinoid pharmacology has made important advances in recent years after the discovery of the cannabinoid receptors (CB1 and CB2). Cannabinoid receptors and their endogenous ligands have provided an excellent platform for the investigation of the therapeutic effects of cannabinoids. It is well known that CB1 and CB2 are heterotrimeric Gi/o-protein-coupled receptors and that they are both expressed in the periphery and the CNS. However, CB1 expression is predominant in the CNS, especially on presynaptic nerves, and CB2 is primarily expressed on immune cells.”

“Cannabinoids are potent anti-inflammatory agents and they exert their effects through induction of apoptosis, inhibition of cell proliferation, suppression of cytokine production and induction of T-regulatory cells (Tregs).”

“Executive summary

  • Cannabinoids, the active components of Cannabis sativa, and endogenous cannabinoids mediate their effects through activation of specific cannabinoid receptors known as cannabinoid receptor 1 and 2 (CB1 and CB2).
  • The cannabinoid system has been shown both in vivo and in vitro to be involved in regulating the immune system through its immunomodulatory properties.
  • Cannabinoids suppress inflammatory response and subsequently attenuate disease symptoms. This property of cannabinoids is mediated through multiple pathways such as induction of apoptosis in activated immune cells, suppression of cytokines and chemokines at inflammatory sites and upregulation of FoxP3+ regulatory T cells.
  • Cannabinoids have been tested in several experimental models of autoimmune disorders such as multiple sclerosis, rheumatoid arthritis, colitis and hepatitis and have been shown to protect the host from the pathogenesis through induction of multiple anti-inflammatory pathways.
  • Cannabinoids may also be beneficial in certain types of cancers that are triggered by chronic inflammation. In such instances, cannabinoids can either directly inhibit tumor growth or suppress inflammation and tumor angiogenesis.”                      http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2828614/

The cannabinergic system as a target for anti-inflammatory therapies.

“Habitual cannabis use has been shown to affect the human immune system, and recent advances in endocannabinoid research provide a basis for understanding these immunomodulatory effects. Cell-based experiments or in vivo animal testing suggest that regulation of the endocannabinoid circuitry can impact almost every major function associated with the immune system.

 These studies were assisted by the development of numerous novel molecules that exert their biological effects through the endocannabinoid system. Several of these compounds were tested for their effects on immune function, and the results suggest therapeutic opportunities for a variety of inflammatory diseases such as multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease, atherosclerosis, allergic asthma, and autoimmune diabetes through modulation of the endocannabinoid system.”

http://www.ncbi.nlm.nih.gov/pubmed/16918457

Therapeutic potential of cannabinoid-based drugs.

Abstract

“Cannabinoid-based drugs modeled on cannabinoids originally isolated from marijuana are now known to significantly impact the functioning of the endocannabinoid system of mammals. This system operates not only in the brain but also in organs and tissues in the periphery including the immune system. Natural and synthetic cannabinoids are tricyclic terpenes, whereas the endogenous physiological ligands are eicosanoids. Several receptors for these compounds have been extensively described, CB1 and CB2, and are G protein-coupled receptors; however, cannabinoid-based drugs are also demonstrated to function independently of these receptors. Cannabinoids regulate many physiological functions and their impact on immunity is generally antiinflammatory as powerful modulators of the cytokine cascade. This anti-inflammatory potency has led to the testing of these drugs in chronic inflammatory laboratory paradigms and even in some human diseases. Psychoactive and nonpsychoactive cannabinoid-based drugs such as Delta9-tetrahydrocannabinol, cannabidiol, HU-211, and ajulemic acid have been tested and found moderately effective in clinical trials of multiple sclerosis, traumatic brain injury, arthritis, and neuropathic pain. Furthermore, although clinical trials are not yet reported, preclinical data with cannabinoid-based drugs suggest efficacy in other inflammatory diseases such as inflammatory bowel disease, Alzheimer’s disease, atherosclerosis, and osteoporosis.”

http://www.ncbi.nlm.nih.gov/pubmed/17713029

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