Tag Archives: treatments

Cannabinoids and Parkinson’s disease.

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Abstract

“Cannabinoid-based medicines have been proposed as clinically promising therapies in Parkinson’s disease (PD), given the prominent modulatory function played by the cannabinoid signaling system in the basal ganglia. Supporting this pharmacological potential, the cannabinoid signaling system experiences a biphasic pattern of changes during the progression of PD. Thus, early and presymptomatic stages, characterized by neuronal malfunctioning but little evidence of neuronal death, are associated with desensitization/downregulation of CB(1) receptors. It was proposed that these losses may be part of the pathogenesis itself, since they can aggravate different cytotoxic insults which are controlled in part by cannabinoid signals, mainly excitotoxicity but also oxidative stress and glial activation. By contrast, intermediate and, in particular, advanced stages of parkinsonism characterized by a profound nigral degeneration and occurrence of major parkinsonian symptoms (e.g. bradykinesia), are associated with upregulatory responses of CB(1) receptors, possibly CB(2) receptors too, and the endocannabinoid ligands for both receptor types. This would explain the motor inhibition typical of this disease and the potential proposed for CB(1) receptor antagonists in attenuating the bradykinesia typical of PD. In addition, certain cannabinoid agonists have been proposed to serve as neuroprotective molecules in PD, given their well-demonstrated capability to reduce excitotoxicity, calcium influx, glial activation and, in particular, oxidative injury that cooperatively contribute to the degeneration of nigral neurons. However, the potential of cannabinoid-based medicines in PD have been still scarcely studied at the clinical level despite the existence of solid and promising preclinical evidence. Considering the relevance of these preclinical data, the need for finding treatments for motor symptoms that may be alternative to classic dopaminergic replacement therapy, and the lack of efficient neuroprotective strategies in PD, we believe it is of major interest to develop further studies that allow the promising expectations generated for these molecules to progress from the present preclinical evidence towards a real clinical application.”

http://www.ncbi.nlm.nih.gov/pubmed/19839934

An overview of Parkinson’s disease and the cannabinoid system and possible benefits of cannabinoid-based treatments.

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Abstract

“Parkinson’s disease (PD) is a slowly progressive neurodegenerative disorder with a heterogeneous clinical picture and a variable rate of progression. PD is characterized by degeneration of the pigmented neuromelanin bearing cells of the pars compacta of the substantia nigra that leads to a severe dopaminergic denervation of the striatum. Current treatments for PD rely on dopamine replacement therapy, most commonly with the dopamine precursor levodopa. Despite the many recent advances in the symptomatic treatment of PD, there is still no realistic prospect for a cure. In recent years, new data support the idea of a relevant role for the cannabinoid system in PD. As cannabinoids have neuroprotective properties, they have been proposed as potentially useful neuroprotective substances in PD, as well as to alleviate some symptoms in specific circumstances (i.e. parkinsonian tremor associated with overactivity to the subthalamic nucleus; levodopa-induced dyskinesia). By contrast, CB(1) receptor antagonists might be useful to reduce bradykinesia in patients refractory to classic levodopa treatment. The present article will review all data about the relationship between PD and the cannabinoid system including: i) the usefulness of cannabinoid-related compounds to alleviate some PD symptoms; ii) that cannabinoid-based compounds might provide protection against the progression of neuronal injury characteristic of this disease; iii) the influence of cannabinoids on local inflammatory events associated with the pathogenesis in PD. Collectively, all these evidence support that the management of the cannabinoid system might represent a new approach to the treatment of PD.”

http://www.ncbi.nlm.nih.gov/pubmed/17168732

Smoked Medical Cannabis May Be Beneficial as Treatment for Chronic Neuropathic Pain, Study Suggests.

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“Medicinal marijuana. A new study provides evidence that cannabis may offer relief to patients suffering from chronic neuropathic pain. (Credit: iStockphoto)”
 

“The medicinal use of cannabis has been debated by clinicians, researchers, legislators and the public at large for many years as an alternative to standard pharmaceutical treatments for pain, which may not always be effective and may have unwanted side effects. A new study by McGill University Health Centre (MUHC) and McGill University researchers provides evidence that cannabis may offer relief to patients suffering from chronic neuropathic pain.”

“This is the first trial to be conducted where patients have been allowed to smoke cannabis at home and to monitor their responses, daily,” says Dr. Mark Ware, lead author of the study, who is also Director of Clinical Research at the Alan Edwards Pain Management Unit at the MUHC and an assistant professor of anesthesia in McGill University’s Faculty of Medicine, and neuroscience researcher at the Research Institute of the MUHC.

In this study, low doses (25mg) of inhaled cannabis containing approximately 10% THC (the active ingredient in cannabis), smoked as a single inhalation using a pipe three times daily over a period of five days, offered modest pain reduction in patients suffering from chronic neuropathic pain (pain associated with nerve injury) within the first few days. The results also suggest that cannabis improved moods and helped patients sleep better. The effects were less pronounced in cannabis strains containing less than 10% THC.

“The patients we followed suffered from pain caused by injuries to the nervous system from post-traumatic (e.g. traffic accidents) or post-surgical (e.g. cut nerves) events, and which was not controlled using standard therapies” explains Dr. Ware. “This kind of pain occurs more frequently than many people recognize, and there are few effective treatments available. For these patients, medical cannabis is sometimes seen as their last hope.”

“This study marks an important step forward because it demonstrates the analgesic effects of cannabis at a low dose over a shot period of time for patients suffering from chronic neuropathic pain,” adds Dr. Ware. The study used herbal cannabis from Prairie Plant Systems (under contract to Health Canada to provide cannabis for research and medical purposes), and a 0% THC ‘placebo’ cannabis from the USA.”

Read more:http://www.sciencedaily.com/releases/2010/08/100830094926.htm

Marijuana-Like Chemical May Help Autism And Fragile X Syndrome Symptoms

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“American and European researchers have found that increasing natural marijuana-like chemicals in the brain may help correct behavioral issues related to autism.

Daniele Piomelli of UC Irvine and Olivier Manzoni of INSERM, the French national research agency, led the study, which could result in treatments of anxiety and cognitive defects in individuals with fragile X syndrome, the most common known genetic cause of autism, according to a press release by UC Irvine.

The study examined 2-AG, which naturally occurs in the brain and is in a class of chemicals called endocannabinoid transmitters. These transmitters allow for the efficient transport of electrical signals at synapses, which is severely limited in people with fragile X syndrome.

The researchers treated mice that exhibited symptoms of fragile X syndrome with novel compounds that correct 2-AG protein signaling in the brain. And the results were promising–the mice showed “dramatic behavioral improvements in maze tests measuring anxiety and open-space acceptance,” UCI reports.

Piomelli said this is the first study to identify the role of naturally-occuring endocannabinoids, which share a similar chemical structure with THC, the primary psychoactive component of marijuana. “What we hope is to one day increase the ability of people with fragile X syndrome to socialize and engage in normal cognitive functions,” said Piomelli, a UCI professor of anatomy and neurobiology.

“It would be either an oral or injected drug but that’s at the very end stage of drug discovery, and we are at the very early stage of drug discovery,” Kwang Mook Jung, a researcher on the study and UCI professor, told The Huffington Post.

In addition, his study of endocannabinoids could result in new treatments for anxiety, pain, depression and obesity, according to UCI.”

http://www.huffingtonpost.com/2012/09/27/marijuana-chemical-autism-fragile-x_n_1920320.html

 

Toward Fulfilling the Promise of Molecular Medicine in Fragile X Syndrome

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“Fragile X syndrome (FXS) is the most common inherited form of mental retardation and a leading known cause of autism. It is caused by loss of expression of the fragile X mental retardation protein (FMRP), an RNA-binding protein that negatively regulates protein synthesis. In neurons, multiple lines of evidence suggest that protein synthesis at synapses is triggered by activation of group 1 metabotropic glutamate receptors (Gp1 mGluRs) and that many functional consequences of activating these receptors are altered in the absence of FMRP. These observations have led to the theory that exaggerated protein synthesis downstream of Gp1 mGluRs is a core pathogenic mechanism in FXS. This excess can be corrected by reducing signaling by Gp1 mGluRs, and numerous studies have shown that inhibition of mGluR5, in particular, can ameliorate multiple mutant phenotypes in animal models of FXS. Clinical trials based on this therapeutic strategy are currently under way. FXS is therefore poised to be the first neurobehavioral disorder in which corrective treatments have been developed from the bottom up: from gene identification to pathophysiology in animals to novel therapeutics in humans. The insights gained from FXS and other autism-related single-gene disorders may also assist in identifying molecular mechanisms and potential treatment approaches for idiopathic autism…

It is already clear that diverse molecular mechanisms can contribute to the synaptic abnormalities that underlie ASDs. In order to design appropriate therapeutic strategies for idiopathic autism, it will be critical to identify biomarkers that report the pathophysiological processes at work in the brains of the affected individuals.

Based on these findings, treatments that successfully target protein synthesis pathways in the single-gene disorders mentioned above, including mGluR5 modulators, may very well have broader therapeutic applications in idiopathic autism.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3100156/

 

Would some cannabinoids ameliorate symptoms of autism?

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“Cannabidiol (CBD) is a major nonpsychotropic constituent of cannabis sativa, which unlike the other major constituent delta9-tetrahydrocannabinol (delta9-THC), is virtually inactive at both of its central nervous system receptors. In one study, cell-based calcium mobilization and electrophysiological assays were used to identify and characterize several novel cannabinoid TRPV2 agonists in cultured rat dorsal root ganglion neurons. Among these, CBD was found to be the most robust and potent, followed by delta9-THC and cannabinol. Those cannabinoids may, accordingly, possess the ability, due to their action as TRPV2 agonists, to increase the release of both oxytocin and vasopressin enhancing the stimulation of oxytocin receptor and V1a receptors at the same time. CBD displays a plethora of other actions including anticonvulsive, sedative, hypnotic, antipsychotic, anti-inflammatory and neuroprotective properties. CBD and delta9-THC are components of drugs commercialized, in certain countries, as treatments for neuropathic pain, overactive bladder, and spasticity in patients suffering from multiple sclerosis. Thus, despite their action on oxytocin and vasopressin release, CBD and delta9-THC may help in improving symptoms of ASD by their sedative, antipsychotic, anticonvulsant and tranquilizing effects. In addition, the cannabinoid system has already been shown to be implicated in social behavior in rats.
 
The administration of cannabinoids for children and adolescents suffering from ASD is a controversial legal and ethical issue. Instead, those cannabinoids may be tested when administered to animals presenting autistic symptoms. Animal models of autistic symptoms exist especially in rodents that have their oxytocin and/or vasopressin function impaired such as mice or rats lacking the oxytocin or vasopressin gene or one of their receptors]. Whenever cannabinoids were found efficient in animal models of autism, the rationale supporting their efficacy may outweigh their legal and ethical adversities, when administered to children in the setting of randomized controlled studies.”
 

Cannabinoids and neuroinflammation

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Abstract

“Growing evidence suggests that a major physiological function of the cannabinoid signaling system is to modulate neuroinflammation. This review discusses the anti-inflammatory properties of cannabinoid compounds at molecular, cellular and whole animal levels, first by examining the evidence for anti-inflammatory effects of cannabinoids obtained using in vivo animal models of clinical neuroinflammatory conditions, specifically rodent models of multiple sclerosis, and second by describing the endogenous cannabinoid (endocannabinoid) system components in immune cells. Our aim is to identify immune functions modulated by cannabinoids that could account for their anti-inflammatory effects in these animal models.”

Conclusion

“Cells involved in neuroinflammation express functional cannabinoid receptors and produce and degrade endocannabinoids, suggesting that the endocannabinoid signaling system has a regulatory function in the inflammatory response. Specifically, during neuroinflammation, there is an upregulation of components involved in the cannabinoid signaling system. This suggests that the cannabinoid signaling system participates in the complex development of this disease, which includes a tight orchestration of the various immune cells involved. If this is the case, the cannabinoid signaling machinery may provide ideal targets, since these would be more susceptible to pharmacological effects than those in the same system under healthy conditions. In line with this, cannabinoid compounds alter the functions of these cells, generally by eliciting anti-inflammatory effects. In the case of MS, neuroinflammation is accompanied by autoimmunity and suppressing the immune response may halt or even prevent associated symptoms. As seen in rodent models of MS, cannabinoids ameliorate the progression of and symptoms associated with neuroinflammation. Future experiments into the components that alter endocannabinoid production and degradation, cannabinoid receptor expression, and effects of cannabinoid receptor agonists on immune cells will provide the necessary information to design more effective treatments for neuroinflammation.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1574256/

CB1 receptor antagonists for the treatment of nicotine addiction.

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Abstract

“Tobacco smoking is the largest cause of avoidable death and disease in developed countries. It is now viewed as a complex bio-psycho-social problem for which effective pharmacological treatments are needed. Nicotine is considered to be the primary compound of tobacco smoke that establishes and maintains tobacco dependence. The addictive effect of nicotine is mediated by activation of the mesolimbic system and the release of dopamine in the nucleus accumbens. Recently, the existence of a specific functional interaction between nicotine and the endocannabinoid system has been reported. Co-administration of sub-threshold doses of a cannabinoid agonist and nicotine produces rewarding effects and chronic nicotine treatment increases endocannabinoid levels in limbic regions. The CB1 receptor plays a key role in this interaction. CB1 knockout mice are less sensitive to the motivational effects of nicotine although this depends on the experimental model. The selective CB1 antagonist, rimonabant (SR141716), reduces nicotine self-administration and nicotine-seeking behavior induced by conditioned cues in rats. Rimonabant appears to reduce nicotine addiction by attenuating the hyperactivation of the endocannabinoid system and the mesolimbic dopaminergic neuronal pathway. Rimonabant may be considered as a potential alternative to the current substitutive treatments of nicotine addiction and may offer a new hope for the treatment of smokers who wish to quit.”

http://www.ncbi.nlm.nih.gov/pubmed/15935455

Cannabinoid CB1 receptor antagonists as potential pharmacotherapies for drug abuse disorders.

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Abstract

“Since the discovery of the cannabinoid CB1 receptor (CB1R) in 1988, and subsequently of the CB2 receptor (CB2R) in 1993, there has been an exponential growth of research investigating the functions of the endocannabinoid system. The roles of CB1Rs have been of particular interest to psychiatry because of their selective presence within the CNS and because of their association with brain-reward circuits involving mesocorticolimbic dopamine systems. One potential role that has become of considerable focus is the ability of CB1Rs to modulate the effects of the drugs of abuse. Many drugs of abuse elevate dopamine levels, and the ability of CB1R antagonists or inverse agonists to modulate these elevations has suggested their potential application as pharmacotherapies for treating drug abuse disorders. With the identification of the selective CB1R antagonist, rimonabant, in 1994, and subsequently of other CB1R antagonists, there has been a rapid expansion of research investigating their ability to modulate the effects of the drugs of abuse. This review highlights some of the preclinical and clinical studies that have examined the effects of CB1R antagonists under conditions potentially predictive of their therapeutic efficacy as treatments for drug abuse disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/19367507

Drug Addiction

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Abstract

“Many drugs of abuse, including cannabinoids, opioids, alcohol and nicotine, can alter the levels of endocannabinoids in the brain. Recent studies show that release of endocannabinoids in the ventral tegmental area can modulate the reward-related effects of dopamine and might therefore be an important neurobiological mechanism underlying drug addiction. There is strong evidence that the endocannabinoid system is involved in drug-seeking behavior (especially behavior that is reinforced by drug-related cues), as well as in the mechanisms that underlie relapse to drug use. The cannabinoid CB1 antagonist/inverse agonist rimonabant has been shown to reduce the behavioral effects of stimuli associated with drugs of abuse, including nicotine, alcohol, cocaine, and marijuana. Thus, the endocannabinoid system represents a promising target for development of new treatments for drug addiction.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3039293/