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

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“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

Evaluation of oral cannabinoid-containing medications for the management of interferon and ribavirin-induced anorexia, nausea and weight loss in patients treated for chronic hepatitis C virus

  “The systemic and cognitive side effects of hepatitis C virus (HCV) therapy may be incapacitating, necessitating dose reductions or abandonment of therapy. Oral cannabinoid-containing medications (OCs) ameliorate chemotherapy-induced nausea and vomiting, as well as AIDS wasting syndrome. The efficacy of OCs in managing HCV treatment-related side effects is unknown.”

 

“Although formal studies are lacking, there is anecdotal evidence that cannabis may be beneficial by alleviating common side effects associated with interferon-ribavirin, including anorexia, nausea, weight loss and insomnia. Despite the potential benefits of cannabis, concerns related to the long-term medical complications of inhaled cannabis use and the inability to legally obtain this product limit the use of it as a therapeutic intervention.”

“Oral cannabinoid-containing medications (OCs) have multiple potential therapeutic uses due to their analgesic, antiemetic, anticonvulsant, bronchodilatory and anti-inflammatory effects. They have been shown in clinical trials to ameliorate chemotherapy-induced nausea, to benefit those with AIDS wasting syndrome and to reduce spasticity in multiple sclerosis patients.”

“CONCLUSIONS:

The present retrospective cohort analysis found that OC use is often effective in managing HCV treatment-related symptoms that contribute to weight loss, and may stabilize weight decline once initiated.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2662895/

Recent advantages in cannabinoid research.

Abstract

“Although the active component of cannabis Delta9-THC was isolated by our group 35 years ago, until recently its mode of action remained obscure. In the last decade it was established that Delta9-THC acts through specific receptors – CB1 and CB2 – and mimics the physiological activity of endogenous cannabinoids of two types, the best known representatives being arachidonoylethanolamide (anandamide) and 2-arachidonoylglycerol (2-AG). THC is officially used against vomiting caused by cancer chemotherapy and for enhancing appetite, particularly in AIDS patients. Illegally, usually by smoking marijuana, it is used for ameliorating the symptoms of multiple sclerosis, against pain, and in a variety of other diseases. A synthetic cannabinoid, HU-211, is in advanced clinical tests against brain damage caused by closed head injury. It may prove to be valuable against stroke and other neurological diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/10575284

Cannabis and endocannabinoid modulators: Therapeutic promises and challenges

Abstract

  “The discovery that botanical cannabinoids such as delta-9 tetrahydrocannabinol exert some of their effect through binding specific cannabinoid receptor sites has led to the discovery of an endocannabinoid signaling system, which in turn has spurred research into the mechanisms of action and addiction potential of cannabis on the one hand, while opening the possibility of developing novel therapeutic agents on the other. This paper reviews current understanding of CB1, CB2, and other possible cannabinoid receptors, their arachidonic acid derived ligands (e.g. anandamide; 2 arachidonoyl glycerol), and their possible physiological roles. CB1 is heavily represented in the central nervous system, but is found in other tissues as well; CB2 tends to be localized to immune cells. Activation of the endocannabinoid system can result in enhanced or dampened activity in various neural circuits depending on their own state of activation. This suggests that one function of the endocannabinoid system may be to maintain steady state. The therapeutic action of botanical cannabis or of synthetic molecules that are agonists, antagonists, or which may otherwise modify endocannabinoid metabolism and activity indicates they may have promise as neuroprotectants, and may be of value in the treatment of certain types of pain, epilepsy, spasticity, eating disorders, inflammation, and possibly blood pressure control.”

Summary

“The discovery of an endocannabinoid signaling system has opened new possibilities for research into understanding the mechanisms of marijuana actions, the role of the endocannabinoid system in homeostasis, and the development of treatment approaches based either on the phytocannabinoids or novel molecules. CB1 agonists may have roles in the treatment of neuropathic pain, spasticity, nausea and emesis, cachexia, and potentially neuroprotection after stroke or head injury. Agonists and antagonists of peripheral CB receptors may be useful in the treatment of inflammatory and autoimmune disorders, as well as hypertension and other cardiovascular diseases. CB1 antagonists may find utility in management of obesity and drug craving. Other novel agents that may not be active at CB receptor sites, but might otherwise modify cannabinoid transport or metabolism, may also have a role in therapeutic modification of the endocannabinoid system. While the short and long term toxicities of the newer compounds are not known, one must expect that at least some of the acute effects (psychotropic effects; hypotension) may be shared by CB agonists. While there are few, long-term serious toxicities attributable to marijuana, extrapolation to newer and more potent agonists, antagonists, and cannabinoid system modulators cannot be assumed. CB1 agonists have the potential in animal models to produce drug preference and drug seeking behaviors as well as tolerance and abstinence phenomena similar to, though not generally as severe as those of other drugs of addiction. There is increasing evidence from human observations that withdrawal from the phytocannabinoids can produce an abstinence syndrome characterized primarily by irritability, sleep disturbance, mood disturbance, and appetite disturbance in chronic heavy users, therefore, such possible effects will need to be considered in the evaluation of newer shorter acting and more potent agonists.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2544377/

Medicinal cannabis: is delta9-tetrahydrocannabinol necessary for all its effects?

Abstract

  “Cannabis is under clinical investigation to assess its potential for medicinal use, but the question arises as to whether there is any advantage in using cannabis extracts compared with isolated Delta9-trans-tetrahydrocannabinol (Delta9THC), the major psychoactive component. We have compared the effect of a standardized cannabis extract (SCE) with pure Delta9THC, at matched concentrations of Delta9THC, and also with a Delta9THC-free extract (Delta9THC-free SCE), using two cannabinoid-sensitive models, a mouse model of multiple sclerosis (MS), and an in-vitro rat brain slice model of epilepsy. Whilst SCE inhibited spasticity in the mouse model of MS to a comparable level, it caused a more rapid onset of muscle relaxation, and a reduction in the time to maximum effect compared with Delta9THC alone. The Delta9THC-free extract or cannabidiol (CBD) caused no inhibition of spasticity. However, in the in-vitro epilepsy model, in which sustained epileptiform seizures were induced by the muscarinic receptor agonist oxotremorine-M in immature rat piriform cortical brain slices, SCE was a more potent and again more rapidly-acting anticonvulsant than isolated Delta9THC, but in this model, the Delta9THC-free extract also exhibited anticonvulsant activity. Cannabidiol did not inhibit seizures, nor did it modulate the activity of Delta9THC in this model. Therefore, as far as some actions of cannabis were concerned (e.g. antispasticity), Delta9THC was the active constituent, which might be modified by the presence of other components. However, for other effects (e.g. anticonvulsant properties) Delta9THC, although active, might not be necessary for the observed effect. Above all, these results demonstrated that not all of the therapeutic actions of cannabis herb might be due to the Delta9THC content.”

http://www.ncbi.nlm.nih.gov/pubmed/14738597

High hopes for new marijuana drug

Marijuana

“Researchers have developed a synthetic compound which gives the benefits of marijuana without the high.

US researchers are developing a marijuana-derived synthetic compound to relieve pain and inflammation without the mood-altering side effects associated with other marijuana based drugs.

Professor Sumner Burstein, from the University of Massachusetts Medical School in Worcester, presented his team’s findings at last week’s national meeting of the American Chemical Society in Boston.

He is hopeful about the potential of the synthetic compound to treat a variety of conditions, including chronic pain, arthritis and Multiple Sclerosis.

The synthetic compound is called ajulemic acid, and has a formula based on that of THC. It has already produced encouraging results in animal studies of pain and inflammation, and is currently being tested on humans.

Exactly how ajulemic acid works is still under investigation but it appears to suppress chemical mediators, such as prostaglandins and cytokines, known to cause inflammation.

“We believe the compound will replace aspirin and similar drugs in most applications because of its lack of toxic side effects”, said Professor Burstein, referring to extensive animal studies, as well as a safety trial of the compound conducted in France last year among 15 healthy volunteers.

No clinically adverse effects were reported, including gastrointestinal ulcers, which have been associated with other non-steroidal anti-inflammatory compounds such as aspirin and ibuprofen.

But most significantly, no mood-altering side effects were reported. With an increasing number of medically beneficial compounds being found in marijuana, such as THC and CBD, researchers have been searching for years for ways to utilise these therapeutically without their associated “high”. They have had little success until now.

“Some people want the high,” admits Professor Burstein. “But the medical community wants efficacy without this effect.”

As well as animal studies of their own that show the compound is as potent a painkiller as morphine, Professor Burstein notes other promising animal studies that have been published. In rodent models of rheumatoid arthritis, the compound prevented joint damage. Tests of MS in rats showed the drug relieves muscle stiffness associated with the disease.

It is now undergoing tests in Germany in a group of 21 patients with chronic pain who take ajulemic acid orally twice daily, in capsule form.

Depending on these results, which will be available in about six weeks, the researchers predict the synthetic compound could be on offer by prescription within two years.

It could also be a promising alternative to current drugs used to treat arthritis, such as COX-2 inhibitors. These have been linked to adverse side effects, including heart attacks and stroke.”

http://www.abc.net.au/science/articles/2002/08/26/656786.htm?fb_action_ids=460011707368809&fb_action_types=og.likes&fb_source=aggregation&fb_aggregation_id=288381481237582

Cannabis drug ‘fights pain without high’

   “Scientists have developed a cannabis-based medicine which relieves chronic pain without any of the “high” normally associated with the drug.

They believe the discovery could pave the way for cannabis-based medication to become available by prescription within two years.

Much of the controversy surrounding the medicinal use of cannabis has centred on fears that it would be used solely for its mood-altering effects.

However, scientists at the University of Massachusetts in the United States say their discovery should help authorities to overcome these fears.

Dr Sumner Burstein and colleagues say early trials of the medication in animals and healthy patients have been promising.

The medication, called ajulemic acid or CT3, has been manufactured in laboratories.

It maximises the medicinal effects of tertrahydrocannabinol – the key ingredient of cannabis – without any of the mind-altering effects.

‘More effective’

In animal tests, this compound was found to be between 10 to 50 times more effective at reducing pain than tetrahydrocannabinol.

Those tests showed that ajulemic acid was very effective at preventing the joint damage associated with arthritis and relieving the muscle stiffness associated with multiple sclerosis.”

Read more: http://news.bbc.co.uk/2/hi/health/2207478.stm

Marijuana-Derived Compound Targets Pain, Inflammation

   “Researchers are developing a marijuana-derived synthetic compound to relieve pain and inflammation without the mood-altering side effects associated with other marijuana based drugs.

  They say the compound could improve treatment of a variety of conditions, including chronic pain, arthritis and multiple sclerosis. Their findings were presented at the 224th national meeting of the American Chemical Society, the world’s largest scientific society.

   The compound, called ajulemic acid, has produced encouraging results in animal studies of pain and inflammation. It is undergoing tests in a group of people with chronic pain and could be available by prescription within two to three years, the researchers say.

 “We believe that [the compound] will replace aspirin and similar drugs in most applications primarily because of a lack of toxic side effects,” says Sumner Burstein, Ph.D., lead investigator in the study and a professor in the department of biochemistry and molecular pharmacology at the University of Massachusetts Medical School in Worcester. “The indications so far are that it’s safe and effective,” he added.”

Read more: http://www.sciencedaily.com/releases/2002/08/020822071026.htm

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