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IACM-Bulletin of November 16, 2014
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Science/Animal — THC and CBD in combination with radiotherapy may be very effective in aggressive brain tumours
When the natural cannabinoids THC (delta-9-tetrahydrocannabinol) and CBD (cannabidiol) are used to treat cancer alongside radiotherapy treatment the growths can virtually disappear. The new research by specialists at St George's, University of London, studied the treatment of brain cancer tumours in cancer cells and mice and discovered that the most effective treatment was to combine THC and CBD together with radiotherapy.
Results demonstrated a duration- and dose-dependent reduction in viability of cancer cells with each cannabinoid. The combination of the two cannabinoids was more than additive. Similarly, pre-treating cells with THC and CBD together for 4 hours before irradiation increased their sensitivity to radiotherapy when compared with pre-treating with either of the cannabinoids individually. These results with cancer cells were confirmed in mice with glioma, an aggressive brain tumour. They showed dramatic reductions in tumour volumes when both cannabinoids were used with irradiation. In the treated group of mice the mean volume was reduced by nearly 90% on day 21 of treatment compared with the non-treated group (5.5 cubic millimetres versus 48.7 cubic millimetres). Researchers wrote that “our data highlight the possibility that these cannabinoids can prime glioma cells to respond better to ionizing radiation, and suggest a potential clinical benefit for glioma patients by using these two treatment modalities.”
Cannabis extract can have dramatic effect on brain cancer, says new research
USA — The two states Oregon and Alaska, as well as the capital Washington have voted for the legalisation of cannabis
Residents of the two states Oregon and Alaska, as well as the U.S. capital voted to legalize cannabis on 4 November. The Oregon and Alaska measures would legalize recreational cannabis use with a network of cannabis shops similar to those operating in Washington State and Colorado, which in 2012 voted to become the first U.S. states to allow cannabis use for recreational use.
A less far-reaching proposal in the District of Columbia (Washington D.C.) to allow cannabis possession but not retail sales won nearly 65 percent of the vote. Advocates have portrayed the District of Columbia measure as a civil rights issue; saying studies have shown that African Americans are disproportionately more likely to be arrested on cannabis charges than are people of other races.
The D.C. measure had been strongly favoured to pass but could still be halted during a review by the U.S. Congress, which has constitutional oversight over the capital. The measure would allow adults 21 and older to possess up to two ounces (57 grams) of cannabis and grow up to six plants.
Science/Human — First diagnosed HIV patients, who use cannabis, have lower viral load
At least daily cannabis use was associated with significant lower plasma HIV viral loads (pVL) in people first diagnosed to be HIV positive. This is the result of a study conducted by researchers of St. Paul's Hospital and the University of British Columbia in Vancouver, Canada. Scientists sought to investigate the possible effects of cannabis use on plasma HIV viral loads among recently seroconverted illicit drug users. They analysed the relationship between viral loads and high-intensity cannabis use among 88 participants who seroconverted following recruitment into the study between May 1996 and March 2012.
Researchers wrote that “consistent with the findings from recent in vitro and in vivo studies, including one conducted among lentiviral-infected primates, we observed a strong association between cannabis use and lower pVL following seroconversion among illicit drug-using participants. Our findings support the further investigation of the immunomodulatory or antiviral effects of cannabinoids among individuals living with HIV/AIDS.”
Science/Human — Cannabis use may be helpful in drug-resistant epilepsy according to case reports
Cannabis use may be helpful in epilepsy according to 18 case reports presented by scientists at the Department of Medicine of the University of Saskatchewan in Saskatoon, Canada. Eighteen patients had a prescription of medicinal cannabis from a total population of 800 patients with epilepsy in the epilepsy centre of the department. Eleven (61%) patients had drug-resistant epilepsy.
The mean consumption dose was 2 grams (range: 0.5-8) grams per day. Ten (56%) patients reported seizure exacerbation when they stopped the cannabis. Only two patients (11%) reported side effects, and all patients found medicinal cannabis very helpful for seizure control and improvement of mood disorder. Authors concluded that patients with epilepsy “using medicinal marijuana have a common profile. They are usually young single men with drug-resistant epilepsy and psychiatric comorbidity. Most used marijuana before formal prescription and all believe the drug was effective on their seizure control. Because of the concurrent use of other antiseizure medications, it is complex to estimate the actual effect of marijuana.”
News in brief
Science/Human — Cannabis use reduced grey brain matter in a small brain region
Brain imaging in 48 cannabis users and 62 non-using controls showed that cannabis users had significantly less brain volume in a small brain region (orbitofrontal gyrus) and higher functional connectivity in the orbitofrontal cortex network. Authors wrote that “longitudinal studies are needed to determine causality of these effects.”
Center for BrainHealth, University of Texas, Dallas, USA.
Filbey FM, et al. Proc Natl Acad Sci U S A. 2014 Nov 10. [in press]
USA — Voters in Florida did not pass medical cannabis law
Voters in Florida did not pass a proposal to legalize cannabis for medical purposes. That proposal was a constitutional amendment, which needed 60 percent of the vote to pass, but had just 57 percent support.
New York Times of 4 November 2014
Guam — Voters legalize the medical use of cannabis
During the general election of 4 November 56 percent of voters want the medicinal use of cannabis be legalized on Guam. Government now will be required to draw up rules and regulations for the dispensing and use of the drug. Guam is a territory of the United States in the western Pacific Ocean.
Guampdn.com of 4 November 2014
Denmark — Government funds research into the medical use of cannabis
The government decided to support medical research into the medical benefits of cannabis by 857 million kroner (about 145 million US dollars, 115 million euros).
Science/Animal — Cannabinoids may help in anxiety disorders
Activation of the endocannabinoid system by cannabinoids in a certain brain region (the periaqueductal grey) attenuates consequences of aversive stimuli. Researchers concluded that “this process may be considered for the development of additional treatments against panic and other anxiety-related disorders”.
Department of Pharmacology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Viana TG, et al. Psychopharmacology (Berl). 2014 Nov 13. [in press]
Science/Animal — Cannabinoids and diclofenac synergistically reduce neuropathic pain
Non-steroidal anti-inflammatory drugs such as diclofenac and inhibitors of MAGL (monoacylglycerol lipase), which inhibits the degradation of endocannabinoids reduced neuropathic pain in mice. The endocannabinoid effect was mediated by the CB1 receptor.
West Virginia University, Department of Psychology, Morgantown, USA.
Crowe MS, et al. Br J Pharmacol. 2014 Nov 13. [in press]
Science/Animal — THC has anti-inflammatory effects in monkey models of HIV infections
THC reduced inflammation in the bowel of macaques infected with the SI virus (SIV), which is similar to HIV in humans. Researchers wrote that THC mediated “suppression of gastrointestinal inflammation and maintenance of intestinal homeostasis.”
Tulane National Primate Research Center, Covington, USA.