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/

Cannabinoids attenuate the effects of aging upon neuroinflammation and neurogenesis.

Abstract

“WIN-55,212-2 (WIN-2) can elicit anti-inflammatory and cognitive-enhancing effect in aged rats. The current study was designed to determine the differential role of the endocannabinoid receptor sub-types 1 (CB1) and 2 (CB2) and transient receptor potential vanilloid 1 receptor (TRPV1) in the reduction of age-associated brain inflammation and their effects on neurogenesis in the dentate gyrus of aged rats. Our results demonstrate that 1) the antagonist actions of WIN-2 at the TRPV1 receptor are responsible for the reduction in microglial activation and 2) the agonist actions of WIN-2 at CB1/2 receptors can trigger neurogenesis in the hippocampus of aged rats. Chronic treatment with WIN-2 established an anti-inflammatory cytokine profile within the hippocampus. Our results provide insight into the role of the endocannabinoid and vanilloid systems upon two different and detrimental aspects of normal and pathological aging, chronic neuroinflammation and decline in neurogenesis.”

http://www.ncbi.nlm.nih.gov/pubmed/19385063

The endocannabinoid system in ageing: a new target for drug development.

Abstract

“Endocannabinoids are a new class of lipids, which include amides, esters and ethers of long chain polyunsaturated fatty acids. 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. AEA is released “on demand” from membrane lipids, and its activity at the receptors is limited by cellular uptake followed by intracellular hydrolysis. Together with AEA and congeners, the proteins which bind, synthesize, transport and hydrolyze AEA form the “endocannabinoid system”. Endogenous cannabinoids are present in the central nervous system and in peripheral tissues, suggesting a physiological role as broad spectrum modulators. This review summarizes the main features of the endocannabinoid system, and the latest advances on its involvement in ageing of central and peripheral cells. In addition, the therapeutic potential of recently developed drugs able to modulate the endocannabinoid tone for the treatment of ageing and age-related human pathologies will be reviewed.”

http://www.ncbi.nlm.nih.gov/pubmed/17100593

Curing addiction with cannabis medicines

“Smokers trying to quit in the future could do it with the help of cannabis based medicines, according to research from The University of Nottingham.

Teams of pharmacologists, studying the cannabis-like compounds which exist naturally in our bodies (endocannabinoids), are exploring the potential for medical treatment. This includes treating conditions as diverse as obesity, diabetes, depression and addiction to substances like nicotine.

Scientists have known about endocannabinoids since the mid-1990s. This led to an explosion in the number of researchers looking into the future medical uses of cannabinoids and cannabis compounds.

Dr Steve Alexander, Associate Professor in the School of Biomedical Sciences, focused on a number of these projects in editing the first themed podcast for the British Journal of Pharmacology.

Dr Alexander said: “It is clear that there is very realistic potential for cannabinoids as medicines. Scientists are looking at a range of possible applications.”

One of these researchers is Professor David Kendall, a cellular pharmacologist at the University: “The brain is full of cannabinoid receptors. And so, not surprisingly with diseases like depression and anxiety, there’s a great deal of interest in exploiting these receptors and in doing so, developing anti-depressant compounds.”

Addiction is a real target – researchers like Professor Kendall believe the endocannabinoids could be a crucial link to addictive behaviour: “We know that the endocannabinoid system is intimately involved in reward pathways and drug seeking behaviour. So this tends to indicate that that if the link involving endocannabinoids and the reward pathway, using inhibitors, can be interrupted, it could turn down the drive to seek addictive agents like nicotine.”

Because cannabinoids have also been shown to bring down blood pressure, it is hoped that related compounds can be used in patients with conditions like hypertension.

Dr Michael Randall, a cardiovascular pharmacologist at the University has looked at how endocannabinoids cause blood vessels to relax. “This could have many implications,” Dr Randall said. “The endocannabinoids appear to lower blood pressure under certain conditions; states of shock for example. If the endocannabinoids are of physiological importance, this could have real therapeutic possibilities.”

“In terms of getting better medicines the endocannabinoid system has a lot to offer,” said Dr Alexander. “The range of cannabis-related medicines is currently limited, but by increasing our knowledge in this area we can increase our stock.”

The University of Nottingham”

http://www.brightsurf.com/news/headlines/36296/Curing_addiction_with_cannabis_medicines.html

Medical Marijuana as Treatment for Alcoholism & Addiction

Medical marijuana is frequently in the news, and hopefully the growing awareness of the benefits of medical marijuana will lead to more sensible regulations and deeper research into why cannabis is so helpful in treating so many different conditions. Among the conditions that medical marijuana can treatis addiction, whether to drugs or alcohol.”

“Medical Marijuana as a Recovery Treatment”

“Marijuana as a recovery treatment is controversial, not least because there is conflicting research about whether medical marijuana is or is not addictive. However, many studies have found that medical marijuana is not addictive, or as harmful, as other drugs such as alcohol and opiates. Additionally, several studies have shown that marijuana can be an effective treatment for recovery from other substances.”

Read more: http://www.unitedpatientsgroup.com/blog/2012/07/26/medical-marijuana-as-treatment-for-alcoholism-addiction/

Marijuana To Control Alcohol Abuse

By Senior News Editor
Reviewed by John M. Grohol, Psy.D. on December 1, 2009

New Strategy Uses Pot To Control Alcohol Abuse “A new research effort has a provocative outcome as University of California-Berkeley researchers suggest substituting cannabis for treatment of heavy alcohol abuse.

Research published in BioMed Central’s open access Harm Reduction Journal features a poll of 350 cannabis users, finding that 40 percent used cannabis to control their alcohol cravings, 66 percent as a replacement for prescription drugs and 26 percent for other, more potent illegal drugs.

Amanda Reiman carried out the study at the UC-Berkeley Patient’s Group, a medical cannabis dispensary.

She said, “Substituting cannabis for alcohol has been described as a radical alcohol treatment protocol. This approach could be used to address heavy alcohol use in the British Isles – people might substitute cannabis, a potentially safer drug than alcohol with less negative side effects, if it were socially acceptable and available.”

Reiman found that 65 percent of people reported using cannabis as a substitute because it has fewer adverse side effects than alcohol, illicit or prescription drugs, 34 percent because it has less withdrawal potential and 57.4 percent because cannabis provides better symptom management.

Reiman believes this discovery brings up two important points.

“First, self-determination, the right of an individual to decide which treatment or substance is most effective and least harmful for them. Secondly, the recognition that substitution might be a viable alternative to abstinence for those who can’t or won’t completely stop using psychoactive substances.”

Speaking about legalization of cannabis, Reiman added, “The economic hardship of the Great Depression helped bring about the end of alcohol prohibition. Now, as we are again faced with economic struggles, the U.S. is looking to marijuana as a potential revenue generator.

“Public support is rising for the legalization of recreational use and remains high for the use of marijuana as a medicine. The hope is that this interest will translate into increased research support and the removal of current barriers to conducting such research, such as the Schedule I/Class B status of marijuana.””

http://psychcentral.com/news/2009/12/01/marijuana-to-control-alcohol-abuse/9863.html

Blockade of the cannabinoid CB1 receptor and alcohol dependence: preclinical evidence and preliminary clinical data.

Abstract

“The present paper summarizes the results of a number of pharmacological studies implicating the cannabinoid CB(1) receptor in the neural circuitry regulating different alcohol-related behaviors in rodents. Specifically, cannabinoid CB(1) receptor antagonists–including the prototype, rimonabant–have been reported to suppress: (a) acquisition and maintenance of alcohol drinking behavior under the 2-bottle “alcohol vs water” choice regimen; (b) the increase in alcohol intake occurring after a period of alcohol abstinence (an experimental model of alcohol relapse); (c) alcohol’s reinforcing and motivational properties measured in rats trained to perform a specific task (e.g., lever-pressing) to access alcohol; (d) reinstatement of extinguished alcohol-seeking behavior triggered in rats by a nicotine challenge or presentation of cues previously associated to alcohol availability (another model of alcohol relapse). Additional data indicate that the opioid receptor antagonists, naloxone and naltrexone, synergistically potentiate the suppressing effect of rimonabant on alcohol intake and alcohol’s motivational properties in rats. Conversely, the two clinical studies conducted to date (one in alcohol-dependent individuals and one in nontreatment-seeking heavy alcohol drinkers) yielded less conclusive results. Unfortunately, the recent discontinuation–due to the occurrence of some psychiatric adverse effects–of all trials with cannabinoid CB(1) receptor antagonists apparently hinders further investigations on the potential of rimonabant in the treatment of alcohol dependence.”

http://www.ncbi.nlm.nih.gov/pubmed/20201816

Cannabinoid receptor 1 blocker rimonabant (SR 141716) for treatment of alcohol dependence: results from a placebo-controlled, double-blind trial.

Abstract

“Multiple lines of evidence suggest that the endocannabinoid system is implicated in the development of alcohol dependence. In addition, in animal models, the cannabinoid receptor 1 blocker rimonabant was found to decrease alcohol consumption, possibly by indirect modulation of dopaminergic neurotransmission. This was a 12-week double-blind, placebo-controlled, proof-of-concept study to assess the possible efficacy of the cannabinoid receptor 1 antagonist rimonabant 20 mg/d (2 x 10 mg) in the prevention of relapse to alcohol in recently detoxified alcohol-dependent patients. A total of 260 patients were included, 258 were exposed to medication, and 208 (80.6%) were men. Patients had an alcohol history of 15 years on average. More patients in the rimonabant group (94/131 [71.8%]) completed treatment compared with the placebo group (79/127 [62.2%]). Although there was a modest effect of rimonabant with respect to relapse rate, there were no statistically significant differences between treatment groups. Approximately 41.5% of the rimonabant group had relapsed to drinking at the end of the study compared with 47.7% of the placebo group (obtained from Kaplan-Meier-curve). Differences were more marked but not statistically significant in patients who relapsed to heavy drinking: 27.7% versus 35.6%, respectively. Safety and tolerance of the drug were good. Similar rates of adverse events were reported between the 2 groups; less patients experienced serious events or discontinued the treatment with rimonabant compared with placebo. Rates of depression-related events were low (3.8% with rimonabant compared with 1.6% with placebo). Patients on rimonabant lost weight (Mean, -1.7 kg) compared with baseline, whereas there was no such change in the placebo group. Weight loss was more pronounced in patients with a higher body mass index. In addition, there was a significant decrease in leptin levels in the rimonabant group compared with baseline. Lack of efficacy in this study may be explained by a very high response rate in the placebo group and a relatively short treatment duration. Taking the substantial numbers of animal studies suggesting a possible role of CB1 antagonists for the treatment of alcohol dependence into account, it seems worthwhile to further test cannabinoid blockers in the treatment of alcoholism.”

http://www.ncbi.nlm.nih.gov/pubmed/18480689

Positron Emission Tomography Shows Elevated Cannabinoid CB (1) Receptor Binding in Men with Alcohol Dependence.

Abstract

“BACKGROUND:

Several lines of evidence link cannabinoid (CB) type 1 (CB (1) ) receptor-mediated endogenous CB (eCB) signaling to the etiology of alcohol dependence (AD). However, to date, only peripheral measures of eCB function have been collected in living humans with AD and no human in vivo data on the potentially critical role of the brain CB (1) receptor in AD have been published. This is an important gap in the literature, because recent therapeutic developments suggest that these receptors could be targeted for the treatment for AD.”

 

“CONCLUSIONS:

These findings agree with preclinical evidence and provide the first, albeit still preliminary in vivo evidence suggesting a role for brain CB (1) receptors in AD. The current study design does not answer the important question of whether elevated CB (1) receptors are a preexisting vulnerability factor for AD or whether elevations develop as a consequence of AD.”

http://www.ncbi.nlm.nih.gov/pubmed/22551199

A Critical Role for the Cannabinoid CB1 Receptors in Alcohol Dependence and Stress-Stimulated Ethanol Drinking

“Although many people drink alcohol regularly, only some become addicted. Several studies have shown that genetic and environmental factors contribute to individual differences in the vulnerability to the effects of alcohol. Among the environmental factors, stress is perhaps the most important trigger for relapse after a period of abstinence. Here we show that ethanol withdrawal symptoms were completely absent in cannabinoid CB1 receptor-deficient mice, although acute effects of ethanol and ethanol tolerance and preference were basically normal. Furthermore, foot-shock stress had no affect on alcohol preference in Cnr1−/− mice, although it induced a dramatic increase in Cnr1+/+ animals. These results reveal a critical role for the CB1 receptor in clinically important aspects of alcohol dependence and provide a rationale for the use of CB1 receptor antagonists in the treatment of alcohol addiction.”

“In summary, the endocannabinoid system does not seem to be crucial for the rewarding effects of ethanol and the manifestation of normal ethanol drinking behaviors. However, it appears to play an important role in the manifestation of stress-induced alcohol drinking and ethanol withdrawal. These results support the notion that the neuronal mechanisms involved in drug reinforcement are dissociable from those involved in withdrawal and reinstatement. Indeed, our results demonstrate that ethanol tolerance and physical dependence can be separated. Thus, CB1 receptor antagonists may be useful for the treatment of alcohol addiction.”

http://www.jneurosci.org/content/23/6/2453.long