Public Release: 28-Jun-2016 Cannabinoids remove plaque-forming Alzheimer's proteins from brain cells
IMAGE: Preliminary lab studies by Salk Professor David Schubert suggest that the molecule THC reduces beta amyloid proteins in human neurons. view more
Credit: Salk Institute
LA JOLLA -- Salk Institute scientists have found preliminary evidence that tetrahydrocannabinol (THC) and other compounds found in marijuana can promote the cellular removal of amyloid beta, a toxic protein associated with Alzheimer's disease.
While these exploratory studies were conducted in neurons grown in the laboratory, they may offer insight into the role of inflammation in Alzheimer's disease and could provide clues to developing novel therapeutics for the disorder.
"Although other studies have offered evidence that cannabinoids might be neuroprotective against the symptoms of Alzheimer's, we believe our study is the first to demonstrate that cannabinoids affect both inflammation and amyloid beta accumulation in nerve cells," says Salk Professor David Schubert, the senior author of the paper.
Alzheimer's disease is a progressive brain disorder that leads to memory loss and can seriously impair a person's ability to carry out daily tasks. It affects more than five million Americans according to the National Institutes of Health, and is a leading cause of death. It is also the most common cause of dementia and its incidence is expected to triple during the next 50 years.
It has long been known that amyloid beta accumulates within the nerve cells of the aging brain well before the appearance of Alzheimer's disease symptoms and plaques. Amyloid beta is a major component of the plaque deposits that are a hallmark of the disease. But the precise role of amyloid beta and the plaques it forms in the disease process remains unclear.
In a manuscript published in June 2016's Aging and Mechanisms of Disease, Salk team studied nerve cells altered to produce high levels of amyloid beta to mimic aspects of Alzheimer's disease.
The researchers found that high levels of amyloid beta were associated with cellular inflammation and higher rates of neuron death. They demonstrated that exposing the cells to THC reduced amyloid beta protein levels and eliminated the inflammatory response from the nerve cells caused by the protein, thereby allowing the nerve cells to survive.
"Inflammation within the brain is a major component of the damage associated with Alzheimer's disease, but it has always been assumed that this response was coming from immune-like cells in the brain, not the nerve cells themselves," says Antonio Currais, a postdoctoral researcher in Schubert's laboratory and first author of the paper. "When we were able to identify the molecular basis of the inflammatory response to amyloid beta, it became clear that THC-like compounds that the nerve cells make themselves may be involved in protecting the cells from dying."
Brain cells have switches known as receptors that can be activated by endocannabinoids, a class of lipid molecules made by the body that are used for intercellular signaling in the brain. The psychoactive effects of marijuana are caused by THC, a molecule similar in activity to endocannabinoids that can activate the same receptors. Physical activity results in the production of endocannabinoids and some studies have shown that exercise may slow the progression of Alzheimer's disease.
Schubert emphasized that his team's findings were conducted in exploratory laboratory models, and that the use of THC-like compounds as a therapy would need to be tested in clinical trials.
In separate but related research, his lab found an Alzheimer's drug candidate called J147 that also removes amyloid beta from nerve cells and reduces the inflammatory response in both nerve cells and the brain. It was the study of J147 that led the scientists to discover that endocannabinoids are involved in the removal of amyloid beta and the reduction of inflammation.
Other authors on the paper include Oswald Quehenberger and Aaron Armando at the University of California, San Diego; and Pamela Maher and Daniel Daughtery at the Salk Institute.
The study was supported by the National Institutes of Health, The Burns Foundation and The Bundy Foundation.
About Salk Institute:
Every cure has a starting point. The Salk Institute embodies Jonas Salk's mission to dare to make dreams into reality. Its internationally renowned and award-winning scientists explore the very foundations of life, seeking new understandings in neuroscience, genetics, immunology and more. The Institute is an independent nonprofit organization and architectural landmark: small by choice, intimate by nature and fearless in the face of any challenge. Be it cancer or Alzheimer's, aging or diabetes, Salk is where cures begin. Learn more at: salk.edu.
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*** National Cancer Institute at the National Institutes of Health ***
Cannabis and Cannabinoids (PDQ®), Cancer Antitumor Effects, Prion prevention, Pain management, muscle relaxer, and Palliative Medicine
Cannabis and Cannabinoids (PDQ®)
Antitumor Effects Appetite Stimulation Analgesia
Cannabinoids are a group of 21-carbon–containing terpenophenolic compounds produced uniquely by Cannabis sativa and Cannabis indica species.[1,2] These plant-derived compounds may be referred to as phytocannabinoids. Although delta-9-tetrahydrocannabinol (THC) is the primary psychoactive ingredient, other known compounds with biologic activity are cannabinol, cannabidiol (CBD), cannabichromene, cannabigerol, tetrahydrocannabivarin, and delta-8-THC. CBD, in particular, is thought to have significant analgesic and anti-inflammatory activity without the psychoactive effect (high) of delta-9-THC.
Antitumor Effects One study in mice and rats suggested that cannabinoids may have a protective effect against the development of certain types of tumors. During this 2-year study, groups of mice and rats were given various doses of THC by gavage. A dose-related decrease in the incidence of hepatic adenoma tumors and hepatocellular carcinoma was observed in the mice. Decreased incidences of benign tumors (polyps and adenomas) in other organs (mammary gland, uterus, pituitary, testis, and pancreas) were also noted in the rats. In another study, delta-9-THC, delta-8-THC, and cannabinol were found to inhibit the growth of Lewis lung adenocarcinoma cells in vitro and in vivo . In addition, other tumors have been shown to be sensitive to cannabinoid-induced growth inhibition.[5-8]
Cannabinoids may cause antitumor effects by various mechanisms, including induction of cell death, inhibition of cell growth, and inhibition of tumor angiogenesis invasion and metastasis.[9-12] One review summarizes the molecular mechanisms of action of cannabinoids as antitumor agents. Cannabinoids appear to kill tumor cells but do not affect their nontransformed counterparts and may even protect them from cell death. These compounds have been shown to induce apoptosis in glioma cells in culture and induce regression of glioma tumors in mice and rats. Cannabinoids protect normal glial cells of astroglial and oligodendroglial lineages from apoptosis mediated by the CB1 receptor.
The effects of delta-9-THC and a synthetic agonist of the CB2 receptor were investigated in hepatocellular carcinoma (HCC). Both agents reduced the viability of hepatocellular carcinoma cells in vitro and demonstrated antitumor effects in hepatocellular carcinoma subcutaneous xenografts in nude mice. The investigations documented that the anti-HCC effects are mediated by way of the CB2 receptor. Similar to findings in glioma cells, the cannabinoids were shown to trigger cell death through stimulation of an endoplasmic reticulum stress pathway that activates autophagy and promotes apoptosis. Other investigations have confirmed that CB1 and CB2 receptors may be potential targets in non-small cell lung carcinoma  and breast cancer.
An in vitro study of the effect of CBD on programmed cell death in breast cancer cell lines found that CBD induced programmed cell death, independent of the CB1, CB2, or vanilloid receptors. CBD inhibited the survival of both estrogen receptor–positive and estrogen receptor–negative breast cancer cell lines, inducing apoptosis in a concentration-dependent manner while having little effect on nontumorigenic, mammary cells.
CBD has also been demonstrated to exert a chemopreventive effect in a mouse model of colon cancer. In the experimental system, azoxymethane increased premalignant and malignant lesions in the mouse colon. Animals treated with azoxymethane and CBD concurrently were protected from developing premalignant and malignant lesions. In in vitro experiments involving colorectal cancer cell lines, the investigators found that CBD protected DNA from oxidative damage, increased endocannabinoid levels, and reduced cell proliferation.
Another investigation into the antitumor effects of CBD examined the role of intercellular adhesion molecule-1 (ICAM-1). ICAM-1 expression has been reported to be negatively correlated with cancer metastasis. In lung cancer cell lines, CBD upregulated ICAM-1, leading to decreased cancer cell invasiveness.
In an in vivo model using severe combined immunodeficient mice, subcutaneous tumors were generated by inoculating the animals with cells from human non-small cell lung carcinoma cell lines. Tumor growth was inhibited by 60% in THC-treated mice compared with vehicle-treated control mice. Tumor specimens revealed that THC had antiangiogenic and antiproliferative effects. However, research with immunocompetent murine tumor models has demonstrated immunosuppression and enhanced tumor growth in mice treated with THC.[21,22]
In addition, both plant-derived and endogenous cannabinoids have been studied for anti-inflammatory effects. A mouse study demonstrated that endogenous cannabinoid system signaling is likely to provide intrinsic protection against colonic inflammation. As a result, a hypothesis that phytocannabinoids and endocannabinoids may be useful in the risk reduction and treatment of colorectal cancer has been developed.[24-27]
Appetite Stimulation Many animal studies have previously demonstrated that delta-9-THC and other cannabinoids have a stimulatory effect on appetite and increase food intake. It is believed that the endogenous cannabinoid system may serve as a regulator of feeding behavior. The endogenous cannabinoid anandamide potently enhances appetite in mice. Moreover, CB1 receptors in the hypothalamus may be involved in the motivational or reward aspects of eating.
Analgesia Understanding the mechanism of cannabinoid-induced analgesia has been increased through the study of cannabinoid receptors, endocannabinoids, and synthetic agonists and antagonists. The CB1 receptor is found in both the central nervous system (CNS) and in peripheral nerve terminals. Similar to opioid receptors, increased levels of the CB1 receptor are found in regions of the brain that regulate nociceptive processing. CB2 receptors, located predominantly in peripheral tissue, exist at very low levels in the CNS. With the development of receptor-specific antagonists, additional information about the roles of the receptors and endogenous cannabinoids in the modulation of pain has been obtained.[31,32]
Cannabinoids may also contribute to pain modulation through an anti-inflammatory mechanism; a CB2 effect with cannabinoids acting on mast cell receptors to attenuate the release of inflammatory agents, such as histamine and serotonin, and on keratinocytes to enhance the release of analgesic opioids has been described.[33-35] One study reported that the efficacy of synthetic CB1- and CB2-receptor agonists were comparable with the efficacy of morphine in a murine model of tumor pain.
J Neurosci. 2007 Sep 5;27(36):9537-44.
Nonpsychoactive cannabidiol prevents prion accumulation and protects neurons against ***prion*** toxicity.
*** Our results suggest that CBD may protect neurons against the multiple molecular and cellular factors involved in the different steps of the neurodegenerative process, which takes place during prion infection. When combined with its ability to target the brain and its lack of toxic side effects, CBD may represent a promising new anti-prion drug.
Report of a parent survey of cannabidiol-enriched cannabis use in pediatric treatment-resistant epilepsy
Brenda E. Porter x Brenda E. Porter Search for articles by this author , Catherine Jacobson x Catherine Jacobson Search for articles by this author Correspondence Corresponding author. email Received: May 24, 2013; Received in revised form: July 23, 2013; Accepted: August 30, 2013; DOI: http://dx.doi.org/10.1016/j.yebeh.2013.08.037 Abstract Full Text Images/Data References Related Articles To view the full text, please login as a subscribed user or purchase a subscription. Click here to view the full text on ScienceDirect.
Severe childhood epilepsies are characterized by frequent seizures, neurodevelopmental delays, and impaired quality of life. In these treatment-resistant epilepsies, families often seek alternative treatments. This survey explored the use of cannabidiol-enriched cannabis in children with treatment-resistant epilepsy. The survey was presented to parents belonging to a Facebook group dedicated to sharing information about the use of cannabidiol-enriched cannabis to treat their child's seizures. Nineteen responses met the following inclusion criteria for the study: a diagnosis of epilepsy and current use of cannabidiol-enriched cannabis. Thirteen children had Dravet syndrome, four had Doose syndrome, and one each had Lennox–Gastaut syndrome and idiopathic epilepsy. The average number of antiepileptic drugs (AEDs) tried before using cannabidiol-enriched cannabis was 12. Sixteen (84%) of the 19 parents reported a reduction in their child's seizure frequency while taking cannabidiol-enriched cannabis. Of these, two (11%) reported complete seizure freedom, eight (42%) reported a greater than 80% reduction in seizure frequency, and six (32%) reported a 25–60% seizure reduction. Other beneficial effects included increased alertness, better mood, and improved sleep. Side effects included drowsiness and fatigue. Our survey shows that parents are using cannabidiol-enriched cannabis as a treatment for their children with treatment-resistant epilepsy. Because of the increasing number of states that allow access to medical cannabis, its use will likely be a growing concern for the epilepsy community. Safety and tolerability data for cannabidiol-enriched cannabis use among children are not available. Objective measurements of a standardized preparation of pure cannabidiol are needed to determine whether it is safe, well tolerated, and efficacious at controlling seizures in this pediatric population with difficult-to-treat seizures.
Marijuana and Epilepsy
Original Contribution| January 11, 2012 Association Between Marijuana Exposure and Pulmonary Function Over 20 Years
Conclusion Occasional and low cumulative marijuana use was not associated with adverse effects on pulmonary function.
Cannabidiol inhibits lung cancer cell invasion and metastasis via intercellular adhesion molecule-1
Cannabinoids inhibit cancer cell invasion via increasing tissue inhibitor of matrix metalloproteinases-1 (TIMP-1).
Cannabis in Palliative Medicine: Improving Care and Reducing Opioid-Related Morbidity
Published online before print March 28, 2011, J HOSP PALLIAT CARE August 2011 vol. 28 no. 5 297-303
Published online ahead of print August 30, 2010 CMAJ 10.1503/cmaj.091414
Smoked cannabis for chronic neuropathic pain: a randomized controlled trial
Our results support the claim that smoked cannabis reduces pain, improves mood and helps sleep. We believe that our trial provides a methodological approach that may be considered for further research. Clinical studies using inhaled delivery systems, such as vaporizers,32,33 are needed.
Cases J. 2009; 2: 7487.
Published online 2009 May 18
Standardized natural product cannabis in pain management and observations at a Canadian compassion society: a case report
The roughly 4000 members of the Green Cross Society find similar benefit from standardized natural product cannabis medicine. To follow, will be publication of the Society's demographic data regarding use for various conditions such as arthritis, fybromyalgia, HIV/AIDS, and chronic pain, to name a few. A breakdown of the illnesses, what strains (cannabinoid profiles) is most effective, and at what dosages will be published at a later time.
Effect of D9-tetrahydrocannabinol, a cannabinoid receptor agonist, on the triggering of transient lower oesophageal sphincter relaxations in dogs and humans
These findings confirm previous findings in dogs and indicate that CB receptors are also involved in the triggering of TLESRs in humans.
Drugs: 9 July 2010 - Volume 70 - Issue 10 - pp 1245-1254
Pharmacological Management of Pain in Patients with Multiple Sclerosis
Cannabinoids have been among the few treatments studied in well designed, randomized, placebo-controlled trials for central neuropathic pain. In the largest of these trials, which included 630 subjects, a 15-week comparison between Δ9-tetrahydrocannabinol and placebo was performed. More patients receiving active treatment perceived an improvement in pain than those receiving placebo, although approximately 20% of subjects reported worsening of pain while on active treatment.
Cannabinoids control spasticity and tremor in a multiple sclerosis model
The exacerbation of these signs after antagonism of the CB1 and CB2 receptors, notably the CB1 receptor, using SR141716A and SR144528 (ref. 8) indicate that the endogenous cannabinoid system may be tonically active in the control of tremor and spasticity. This provides a rationale for patients' indications of the therapeutic potential of cannabis in the control of the symptoms of multiple sclerosis2, and provides a means of evaluating more selective cannabinoids in the future.