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IACM-Bulletin of June 28, 2015
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Science/Human — Laws, which allow the medical use of cannabis in the USA, do not increase the use in adolescents
Cannabis use did not increase among teenagers in the states of the USA in which medical cannabis has become legal, researchers of Columbia University in New York, USA, reported on 15 June 2015. The new analysis is the most comprehensive effort to date to answer a much-debated question: Does decriminalization of cannabis lead more adolescents to begin using it? The study found that states that had legalized medical use had higher prevailing rates of teenage cannabis use before enacting the laws, compared with states where the drug remains illegal. Those higher levels were unaffected by the changes in the law, the study found.
The report, published in The Lancet Psychiatry, covered a 24-year period and was based on surveys of more than one million adolescents in 48 states. A primary concern on both sides of the debate over medical cannabis has been that loosening cannabis restrictions might send the wrong message to young people, and make the drug both more available and more appealing. Teenagers who develop and sustain a heavy, daily habit increase their risk of having cognitive difficulties later on, several studies suggest.
New York Times of 15 June 2015
Science/Human — Reviews on medical benefits of cannabis confirm good evidence for some diseases
Moderate- or high-quality evidence supports the use of cannabis for some medical conditions, but not for others, according to two reviews of past research, published in the Journal of the American Medical Association (JAMA). After reviewing 80 randomized trials that included nearly 6,500 people, researchers found moderate support for using cannabis to treat chronic pain and muscle spasms and involuntary movements.
The evidence wasn't as strong to support cannabis use for nausea and vomiting due to chemotherapy, sleep disorders, HIV-related weight loss and Tourette syndrome, concluded Penny Whiting of University Hospitals Bristol NHS Foundation Trust in the UK and her collaborators. This review was commissioned by the Swiss Federal Office of Public Health. A second review published in the same journal by Dr Kevin Hill of McLean Hospital in Belmont (USA) found similar results. In that review, Hill found high-quality evidence to support the use of cannabis in people with chronic or neuropathic pain, and muscle problems related to multiple sclerosis.
News in brief
Canada — Vancouver regulates cannabis dispensaries
The Vancouver city council has voted to regulate and license the roughly 100 medical cannabis retailers in the city, making it the first city in Canada to do so and drawing fire from Health Minister Rona Ambrose.
USA — Colorado high court ruled that workers can be fired for the medical use of cannabis
The Colorado Supreme Court ruled on 15 June that companies may fire their employees for off-the-job use of medical cannabis that is permitted under state law because cannabis remains outlawed by the federal government.
USA — The Obama administration just made medical cannabis research easier
A long-standing bureaucratic obstacle to privately-funded medical cannabis research has just been removed, effective immediately. The government has removed the necessity for researches to submit a research proposal to a so-called Public Health Service board to review its scientific validity and ethical soundness. Researchers now have to submit their proposal only to the FDA (Food and Drug Administration).
Washington Post of 22 June 2015
Science/Human — THC may be detectable in blood plasma several days after last consumption in frequent cannabis users
In a study with 28 chronic frequent cannabis smokers, who stopped cannabis use, THC concentration in blood plasma was above 2 ng/ml in 16 participants 48 hours after last use. THC-COOH was measurable in 3 of 5 blood samples 30 days after last use and median THC plasma-concentration was 0.3 ng/ml in these 5 blood plasma samples.
National Institute on Drug Abuse, Baltimore, USA.
Karschner EL, et al. Drug Test Anal. 2015 Jun 11. [in press]
Science/Cells — CBD causes relaxation of human arteries
The effects of CBD on endothelial cells of human arteries were investigated. From their research authors concluded that “this study shows, for the first time, that CBD causes vasorelaxation of human mesenteric arteries via activation” of CB1 receptors and vanilloid receptors.
School of Medicine, University of Nottingham, UK.
Stanley CP, et al. Cardiovasc Res. 2015 Jun 19. [in press]
Science/Animal — CBD may be beneficial in heart attacks
Acute myocardial infarction was induced in rabbits, and the effects of intravenous CBD doses of 0.1 mg/kg body weight were investigated. Authors concluded that CBD therapy reduced infarction size and facilitated restoration of heart function and this has potential therapeutic utility.
University Hospital Gasthuisberg, Leuven, Belgium.
Feng Y, et al. J Cardiovasc Pharmacol. 2015 Jun 9. [in press]
Science/Cells — CBD and THC reduce viability of myeloma cells
OWC Pharmaceutical Research, an Israeli company, announced that different combinations of THC and CBD decreased survival of multiple myeloma cells in a concentration-dependent manner. Multiple myeloma is a cancer of plasma cells, a type of white blood cells. The results present up to more than 60% malignant cell death. THC and CBD in different ratios were more effective than THC or CBD alone.
Science/Animal — CBD may cause memory loss and this effect may be reduced by caffeine
CBD was shown to reduce memory and cause reduction in anxiety in zebra fish. A long-term pre-treatment with caffeine reduced memory loss. Authors wrote that “these results indicated that zebrafish have responses to CBD anxiolytic properties that are comparable to other animal models, and high doses changed memory retention.”
Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
Nazario LR et al. Pharmacol Biochem Behav. 2015;135:210-216.
Science/Human — Positive THC findings in hair may be due to external exposition to THC
In a study with 10 participants, who rolled cannabis cigarettes on five consecutive days without consuming cannabis, THCA and THC could be detected in the hair samples from all participants. Authors wrote that “this finding is of particular interest in interpreting THC-positive hair results of children or partners of cannabis users, where such a transfer can occur due to close body contact.”
Institute of Forensic Medicine, Forensic Toxicology, Medical Center - University of Freiburg, Germany.
Moosmann B, et al. Drug Test Anal. 2015 June 21. [in press]
Science — Nine new cannabinoids were detected in high potency cannabis
Nine new cannabinoids were isolated from a high potency cannabis variety. These compounds, which were present in low concentrations, include four hexahydrocannabinols, four tetrahydrocannabinols, and one hydroxylated cannabinol.
National Center for Natural Products Research, The University of Mississippi, USA.
Ahmed SA, et al. Phytochemistry. 2015 Jun 17;117:194-199.
Science/Animal — The high presence of CB2 receptors may be a marker for inflammation in the brain in early stages of Alzheimer’s disease
In a mouse model of Alzheimer’s disease (AD) CB2 receptors were observed, in particular, in amyloid plaques. Authors wrote that their study “indicates that a CB2-specific radiotracer can be used as a biomarker of neuroinflammation in the early preclinical stages of AD, when no significant neuronal loss has yet developed.”
Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, USA.
Savonenko AV, et al. PLoS One 2015;10(6):e0129618.
Science — Stress influences endocannabinoid levels
A review on the effects of stress on the endocannabinoid system shows that stress evokes different changes in the two endocannabinoids, anandamide (AEA) and 2-arachidonoyl glycerol (2-AG), with stress exposure reducing AEA levels and increasing 2-AG levels. Additionally, in almost every brain region examined, exposure to chronic stress reliably causes a down-regulation or loss of CB1 receptors.
Hotchkiss Brain Institute, University of Calgary, Canada.
Morena M, et al. Neuropsychopharmacology. 2015 Jun 12 [in press]
Science/Cells — The activation of CB1 and A1 receptors produces additive neuroprotection against glutamate
The neurotransmitter glutamate produces nerve damage in the brain after brain injury. New research shows that that both CB1 and A1 receptors produce additive cumulative neuroprotection against glutamate-induced toxicity of nerve cells in the hippocampus, a certain brain region.
CICS-UBI - Health Sciences Research Center, University of Beira Interior, Covilhã, Portugal.