Marijuana and its receptor protein in brain control epilepsy

“VCU study is first to test anticonvulsant potential of marijuana and brain recurrent seizures. 

Ingredients in marijuana and the cannabinoid receptor protein produced naturally in the body to regulate the central nervous system and other bodily functions play a critical role in controlling spontaneous seizures in epilepsy, according to a new study by researchers at Virginia Commonwealth University.

The study, the first to look at marijuana and the brain’s cannabinoid system in live animals with spontaneous, recurrent seizures, suggests new avenues that researchers can explore in their search for more-effective drugs to treat epileptic patients who don’t respond to today’s anticonvulsant medications or surgery.

The results appear in the Oct. 1 issue of the Journal of Pharmacology and Experimental Therapeutics.

“Although marijuana is illegal in the United States, individuals both here and abroad report that marijuana has been therapeutic for them in the treatment of a variety of ailments, including epilepsy,” says Dr. Robert J. DeLorenzo, professor of neurology in the VCU School of Medicine.

 “If we can understand how marijuana works to end seizures, we may be able to develop novel drugs that might do a better job of treating epileptic seizures.” 

Epilepsy is one of the most common neurological conditions, characterized by spontaneously recurrent seizures. Approximately 1 percent of Americans have epilepsy, and 30 percent of those patients are resistant to conventional anticonvulsant drug treatments.

Cannabinoids have been used as a natural remedy for seizures for thousands of years, and studies since at least 1974 have found that the primary psychoactive compound in marijuana displays anticonvulsant properties.” 

More:http://www.news.vcu.edu/news/Marijuana_and_its_receptor_protein_in_brain_control_epilepsy

GW Pharmaceuticals: Giving New Meaning To ‘High Potential’

“GW Pharmaceuticals (GWPH) is an UK-based biopharmaceutical company focused on the discovery and development of cannabinoid-based products for a wide range of indications. GW has established a technology platform based on genetically modified cannabis plants and has become a leader in plant-derived cannabinoid therapeutics.

 GW’s lead program is Sativex, a cannabis extract based oromucosal spray whose main actives are the cannabinoids delta-9- tetrahydrocannabinol (THC), and cannabidiol (CBD). It is approved for the treatment of multiple sclerosis (MS) spasticity in 21 countries outside of the U.S and already marketed in seven countries (eight following Italian launch in Q213).

…While MS spasticity has provided proof-of-concept in the worldwide approvability of Sativex, a more meaningful commercial opportunity is in the treatment of opioid-refractory cancer pain. Sativex has been tested in two Phase II trials in cancer pain. The trials have demonstrated that Sativex is safe and effective when used in addition to opioids in patients whose cancer pain is not sufficiently managed by opioids alone. Based on these results, GW has initiated three Phase III trials. The first two are expected to complete during 2014 and support an FDA filing.”

More: http://seekingalpha.com/article/1490392-gw-pharmaceuticals-giving-new-meaning-to-high-potential

Cannabinoids for gastrointestinal diseases: potential therapeutic applications.

“Delta(9)-Tetrahydrocannabinol (the active ingredient of marijuana), as well as endogenous and synthetic cannabinoids, exert many biological functions by activating two types of cannabinoid receptors, CB(1) and CB(2) receptors. CB(1) receptors have been detected on enteric nerves, and pharmacological effects of their activation include gastroprotection, reduction of gastric and intestinal motility and reduction of intestinal secretion.

 The digestive tract also contains endogenous cannabinoids (i.e., the endocannabinoids anandamide and 2-aracidonylglycerol) and mechanisms for endocannabinoid inactivation (i.e., endocannabinoids uptake and enzymatic degradation). Cannabinoid receptors, endocannabinoids and the proteins involved in endocannabinoids inactivation are collectively referred as the ‘endogenous cannabinoid system’.

 A pharmacological modulation of the endogenous cannabinoid system could provide new therapeutics for the treatment of a number of gastrointestinal diseases, including nausea and vomiting, gastric ulcers, irritable bowel syndrome, Crohn’s disease, secretory diarrhoea, paralytic ileus and gastroesophageal reflux disease. Some cannabinoids are already in use clinically, for example, nabilone and delta(9)-tetrahydrocannabinol are used as antiemetics.”

http://www.ncbi.nlm.nih.gov/pubmed/12517253

The pharmacologic and clinical effects of medical cannabis.

“Cannabis, or marijuana, has been used for medicinal purposes for many years. Several types of cannabinoid medicines are available in the United States and Canada. Dronabinol (schedule III), nabilone (schedule II), and nabiximols (not U.S. Food and Drug Administration approved) are cannabis-derived pharmaceuticals.

Medical cannabis or medical marijuana, a leafy plant cultivated for the production of its leaves and flowering tops, is a schedule I drug, but patients obtain it through cannabis dispensaries and statewide programs. The effect that cannabinoid compounds have on the cannabinoid receptors (CB(1) and CB(2) ) found in the brain can create varying pharmacologic responses based on formulation and patient characteristics. The cannabinoid Δ(9) -tetrahydrocannabinol has been determined to have the primary psychoactive effects; the effects of several other key cannabinoid compounds have yet to be fully elucidated. Dronabinol and nabilone are indicated for the treatment of nausea and vomiting associated with cancer chemotherapy and of anorexia associated with weight loss in patients with acquired immune deficiency syndrome. However, pain and muscle spasms are the most common reasons that medical cannabis is being recommended.

Studies of medical cannabis show significant improvement in various types of pain and muscle spasticity. Reported adverse effects are typically not serious, with the most common being dizziness. Safety concerns regarding cannabis include the increased risk of developing schizophrenia with adolescent use, impairments in memory and cognition, accidental pediatric ingestions, and lack of safety packaging for medical cannabis formulations. This article will describe the pharmacology of cannabis, effects of various dosage formulations, therapeutics benefits and risks of cannabis for pain and muscle spasm, and safety concerns of medical cannabis use.”

http://www.ncbi.nlm.nih.gov/pubmed/23386598

The endocannabinoid nervous system: unique opportunities for therapeutic intervention.

“The active principle in marijuana, Delta(9)-tetrahydrocannabinol (THC), has been shown to have wide therapeutic application for a number of important medical conditions, including pain, anxiety, glaucoma, nausea, emesis, muscle spasms, and wasting diseases. Delta(9)-THC binds to and activates two known cannabinoid receptors found in mammalian tissue, CB1 and CB2. The development of cannabinoid-based therapeutics has focused predominantly on the CB1 receptor, based on its predominant and abundant localization in the CNS.

Like most of the known cannabinoid agonists, Delta(9)-THC is lipophilic and relatively nonselective for both receptor subtypes.

Clinical studies show that nonselective cannabinoid agonists are relatively safe and provide therapeutic efficacy, but that they also induce psychotropic side effects. Recent studies of the biosynthesis, release, transport, and disposition of anandamide are beginning to provide an understanding of the role of lipid transmitters in the CNS. This review attempts to link current understanding of the basic biology of the endocannabinoid nervous system to novel opportunities for therapeutic intervention.

This new knowledge may facilitate the development of cannabinoid receptor-targeted therapeutics with improved safety and efficacy profiles.”

http://www.ncbi.nlm.nih.gov/pubmed/11448725

Fatty acid amide hydrolase: a potential target for next generation therapeutics.

Abstract

“Endocannabinoids are amides, esters and ethers of long chain polyunsaturated fatty acids, which act as new lipid mediators. Anandamide (N-arachidonoylethanolamine; AEA) and 2-arachidonoylglycerol are the main endogenous agonists of cannabinoid receptors, able to mimic several pharmacological effects of Delta(9)-tetrahydrocannabinol, the active principle of Cannabis sativa preparations like hashish and marijuana. The activity of AEA at its receptors is limited by cellular uptake through a specific membrane transporter, followed by intracellular degradation by a fatty acid amide hydrolase (FAAH). Growing evidence demonstrates that FAAH is the critical regulator of the endogenous levels of AEA, suggesting that it may serve as an attractive therapeutic target for the treatment of human disorders. In particular, FAAH inhibitors may be next generation therapeutic drugs of potential value for the treatment of pathologies in the central nervous system and in the periphery. Here, the potential applications of these inhibitors for human disease will be reviewed, with an emphasis on the properties of hydro(pero)xy-anandamides. In fact, these oxygenated derivatives of AEA are the most powerful inhibitors of FAAH of natural origin as yet discovered. In addition, new insights into the promoter region of FAAH gene will be presented, and the therapeutic potential of mimetics of transcription factors of this gene in the management of human infertility will be discussed.”

http://www.ncbi.nlm.nih.gov/pubmed/16472164

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

Nonpsychotropic Cannabinoid Receptors Regulate Microglial Cell Migration

“During neuroinflammation, activated microglial cells migrate toward dying neurons, where they exacerbate local cell damage. The signaling molecules that trigger microglial cell migration are poorly understood. In this paper, we show that pathological overstimulation of neurons by glutamate plus carbachol dramatically increases the production of the endocannabinoid 2-arachidonylglycerol (2-AG) but only slightly increases the production of anandamide and does not affect the production of two putative endocannabinoids, homo-γ-linolenylethanolamide and docosatetraenylethanolamide. We further show that pathological stimulation of microglial cells with ATP also increases the production of 2-AG without affecting the amount of other endocannabinoids. Using a Boyden chamber assay, we provide evidence that 2-AG triggers microglial cell migration. This effect of 2-AG occurs through CB2 and abnormal-cannabidiol-sensitive receptors, with subsequent activation of the extracellular signal-regulated kinase 1/2 signal transduction pathway. It is important to note that cannabinol and cannabidiol, two nonpsychotropic ingredients present in the marijuana plant, prevent the 2-AG-induced cell migration by antagonizing the CB2 and abnormal-cannabidiol-sensitive receptors, respectively. Finally, we show that microglial cells express CB2 receptors at the leading edge of lamellipodia, which is consistent with the involvement of microglial cells in cell migration. Our study identifies a cannabinoid signaling system regulating microglial cell migration. Because this signaling system is likely to be involved in recruiting microglial cells toward dying neurons, we propose that cannabinol and cannabidiol are promising nonpsychotropic therapeutics to prevent the recruitment of these cells at neuroinflammatory lesion sites.”

“Because marijuana produces remarkable beneficial effects, patients with multiple sclerosis, for example, commonly use this plant as a therapeutic agent; however, we still lack essential information on the mechanistic basis of these beneficial effects.”

“The marijuana plant, Cannabis sativa, contains >60 cannabinoid compounds, the best known being Δ9-tetrahydrocannabinol (THC), cannabinol (CBN), and cannabidiol (CBD) (for review, see. Cannabinoid compounds produce their biological effects by acting through at least three cannabinoid receptors (see Table1). These include the cloned cannabinoid CB1 receptors, which are expressed predominately in the CNS, the cloned cannabinoid CB2 receptors, which are expressed predominately by immune cells, and the abnormal-cannabidiol-sensitive receptors (hereafter referred to as abn-CBD receptors). The latter receptors have not been cloned yet, but they have been pinpointed pharmacologically in mice lacking CB1 and CB2 receptors and are also known as anandamide (AEA) receptors.”

“We also show that CBN and CBD, two nonpsychotropic bioactive compounds of marijuana, may antagonize the 2-AG-induced recruitment of microglial cells. This is in agreement with the fact that nabilone, a synthetic analog of THC, produces minimal palliative effects against multiple sclerosis symptoms, whereas smoking cannabis is reported to be beneficial. Therefore, our results suggest that bioactive cannabinoids present in the marijuana plant, such as CBN and CBD, are likely to underlie the increased efficacy of cannabis versus nabilone and therefore hold promise as nonpsychotropic therapeutics to treat neuroinflammation.”

http://www.jneurosci.org/content/23/4/1398.long

The endocannabinoid signaling system: a potential target for next-generation therapeutics for alcoholism

“Alcoholism is a complex disorder affecting modern society in many ways, yet there are few effective treatment strategies currently available.”

“Research into the endocannabinoid signaling system has grown exponentially in recent years following the discovery of cannabinoid receptors (CB) and their endogenous ligands, such as anandamide (AEA) and 2-arachidonoylglycerol (2-AG). Important advances have been made in our understanding of the endocannabinoid signaling system in various aspects of alcoholism, including alcohol-seeking behavior. Alcohol increases the synthesis or impairs the degradation of endocannabinoids, leading to a locally elevated endocannabinoid tone within the brain. Elevated endocannabinoid tone might be expected to result in compensatory down-regulation of CB1 receptors or dampened signal transduction. Following release, endocannabinoids diffuse back to the presynaptic neuron where they act as short-range modulators of synaptic activity by altering neurotransmitter release and synaptic plasticity. Mice treated with the CB1 receptor antagonist SR141716A (rimonabant) or homozygous for a deletion of the CB1 receptor gene exhibit reduced voluntary alcohol intake. CB1 knockout mice also show increased alcohol sensitivity, withdrawal, and reduced conditioned place preference. Conversely, activation of CB1 receptor promotes alcohol intake. Recent studies also suggest that elevated endocannabinoid tone due to impaired degradation contributes to high alcohol preference and self-administration. These effects are reversed by local administration of rimonabant, suggesting the participation of the endocannabinoid signaling system in high alcohol preference and self-administration. These recent advances will be reviewed with an emphasis on the endocannabinoid signaling system for possible therapeutic interventions of alcoholism.”

“Overwhelmingly, recent studies suggest that cannabinoids and alcohol activate similar reward pathways. The CB1 receptors also seem to regulate the reinforcing properties of alcohol. The discovery of cannabinoid receptors and their endogenous ligands set a landmark in cannabinoid research. These discoveries impacted significantly on alcohol research, too, since there is now considerable evidence that endocannabinoid signaling plays a key role in alcohol addiction, and this has promising clinical consequences. The purpose of this article is to analyze the interaction between alcohol and endocannabinoid signaling, paying particular attention to the reward mechanism. Therapeutic aspects driving from these new insights are also discussed.”

“THERAPEUTIC OPPORTUNITY”

“Although the detailed physiology, biochemistry and pathophysiology of the endocannabinoid signaling system have not been fully investigated, there is already overwhelming evidence to indicate that pharmacological modulation of the endocannabinoid signaling system could provide new treatments for a number of disease states, including alcohol addiction. Recently it was reported that rimonabant holds an important therapeutic role in treating liver fibrosis and alcohol abuse accounts for more than half of the prevalence of liver fibrosis and cirrhosis in the western world. Therefore, it is important to examine whether alcohol-induced liver fibrosis and cirrhosis results in increased endocannabinoid levels and rimonabant reverses alcohol-induced liver fibrosis/cirrhosis. In terms of drug development, the CB1 receptor antagonist rimonabant has progressed furthest and is in late phase III trials for the treatment of obesity and as an aid for smoking cessation. An NIAAA clinical study of the effectiveness of rimonabant to reduce voluntary alcohol drinking has progressed to phase I trials. Pending results of the clinical trials, rimonabant could become an important addition to the limited arsenal of effective treatments for alcoholism. During drug abuse there are changes in endocannabinoid levels in various brain regions. Therefore, drugs which regulate the level of endocannabinoids by inhibiting their metabolism (FAAH inhibitors such as URB597) or uptake (AM404) could locally target sites while limiting effects in uninvolved cognitive areas to produce a higher therapeutic value. Cannabinoid interactions with the dopamine system have been offered as a possible mechanism for some of the therapeutic potential of cannabinoid-based drugs in alcoholism. A recent study provides evidence of the ability of CB1 receptor antagonist to mitigate alcohol-withdrawal symptoms, and block the formation of physical dependency by inhibiting alcohol intake. Recent data on the role of CB1 receptors in alcohol drinking behavior, including alcohol tolerance as discussed in the earlier sections, clearly suggest that agents such as CB1 receptor antagonists, including rimonabant, will be promising therapeutic agents for the treatment of alcoholism.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1975858/

Addiction and the pharmacology of cannabis: implications for medicine and the law.

Abstract

“The topic of drug addiction or misuse of drugs has numerous far-reaching ramifications into areas such as neuroscience, medicine and therapeutics, toxicology, epidemiology, national and international economics and politics, and the law. The general principles of drug addiction are first summarised. A recurring and intrinsic problem is lack of adequate characterisation of the independent variable, namely the drug taken. Secondly, it is not feasible to allocate subjects randomly to treatments. Thirdly, the heterogeneity of different forms of addiction precludes facile generalisations. “A problem drug user is anyone who experiences social, psychological, physical, or legal problems related to intoxication, and/or regular excessive consumption, and/or dependence as a consequence of their use of drugs” (UK Advisory Council on Misuse of Drugs, 1982). Cannabis is a genus of flowering plants whose products are used as recreational drugs. Claims have been made for a range of therapeutic properties. Its two main active principles are delta9 – tetrahydrocannabinol (THC) and cannabidiol (CBD). These compounds have contrasting pharmacological properties. THC is suspected of causing psychotic phenomena, but CBD seems more sedative and may even be antipsychotic. The past use of cannabis, particularly the concentrations of THC and CBD, can be monitored with hair analysis. Recent studies involving the administration of THC and CBD to human subjects are reviewed. Suggestions are made for further research into the pharmacology and toxicology of CBD. Such data may also point to a more rational evidence-based approach to the legal control of cannabis preparations.”

http://www.ncbi.nlm.nih.gov/pubmed/19306615