Pubdate: Sunday, 5 March 2000
Source: Association for Cannabis as Medicine (ACM), Germany
Contact: info@acmed.org
Address: Arnimstrasse 1a, D-50825 Cologne, Germany
Website: http://www.acmed.org
Phone: +49-221-912 30 33
Fax: +49-221-130 05 91
Cannabis science news
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ACM-Bulletin of 5 March 2000
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NEW MAIL ADDRESS of the ACM (see below)
* Science: THC destroys brain cancer in animal research
* Science: Cannabinoids reduce tremor in animal model of
multiple sclerosis
* Science: Smoking marijuana my increase risk of heart attack
1.
Science: THC destroys brain cancer in animal research
Delta-9-tetrahydrocannbinol (THC), the major active component
of the cannabis plant, and a synthetic cannabinoid induced a
remarkable regression of a usually fatal type of brain tumour
when tested on laboratory rats, Spanish researchers said on 28
February in the journal Nature Medicine.
Malignant gliomas, a quick-killing cancer for which there is
currently no effective treatment, were induced in 45 rats. A third
were treated with THC, and another third with the cannabinoid
agonist WIN-55,212-2, while the remainder were left untreated.
Within 18 days the untreated rats died. But the two cannabinoids
had a dramatic effect, destroying the tumours in a third of the
treated rats over a period of seven days, and prolonging the life of
another third by up to six weeks.
12 days after cell injection THC or WIN-55,212-2 were
continually injected directly at the site of tumour inoculation over a
period of 7 days. THC administration was ineffective in 3 animals
and increased the survival of 9 rats up to 19-35 days. The tumour
was completely eradicated in 3 of the treated animals. Likewise
the synthetic cannabinoid was ineffective in 6 rats, increased the
survival of 4 rats up to 19-43 days; and completely eradicated the
tumour in 5 animals.
The team led by Dr Manuel Guzman from the Complutense
university in Madrid said: "These results may provide the basis for
a new therapeutic approach for the treatment of malignant
gliomas." He said that the current experiment tested THC at very
low doses and at a late stage, when untreated rats were already
starting to die. He predicts that THC should work better if given
earlier. But cancer treatments that work in animals may be too
toxic or not effective in humans.
Cannabinoids are thought to kill tumour cells by inducing
programmed cell death, or apoptosis, via an intracellular signalling
mechanism. Experiments carried out with two subclones of glioma
cells in culture demonstrated that cannabinoids signal apoptosis by
a pathway involving cannabinoid receptors, sustained
accumulation of the lipid ceramide and Raf-1/ERK (extracellular
signal-regulated kinase) activation, inducing a cascade of
reactions that leads to cell death.
In a commentary for Nature Medicine, Dr. Daniele Piomelli, from
the University of California at Irvine, said the findings could have
important implications. This would be the first convincing study to
show that a marijuana-based drug treatment may combat cancer.
If the drug works as well in humans, Piomelli says, "then this will
be a paper of great importance." But it would take a lot of testing,
both in animals and in people, to prove it is effective. The smoking
of marihuana would not be effective.
(Sources: Galve-Roperph I, Sanchez C, Cortesz ML, Gomez del
Pulgar T, Izquierdo M, Guzman M: Antitumoral action of
cannabinoids: involvement of sustained ceramide accumulation
and ERK activation. Nature Medicine 6, 313-319 (2000); Piomelli
D: Nature Medicine 6, 255-256, (2000); UPI of 28 February 2000;
AP of 29 February 2000; Reuters of 29 February 2000; PA News
of 29 February 2000, personel communication by Manual Guzman)
2.
Science: Cannabinoids reduce tremor in animal model of multiple
sclerosis
In the journal Nature scientists said on 1 March they had for the
first time scientifically demonstrated the link between cannabis
and the suppression of multiple sclerosis (MS) symptoms. The
study with mice suffering from chronic allergic encephalomyelitis
(CREAE) -- an animal model for MS -- found that cannabinoids
ameliorated CREAE symptoms.
The mouse MS study "is the first to show definitive objective
evidence that synthetic compounds, which stimulate the receptor
that cannabis (marijuana) binds to, can alleviate spasticity and
tremor in an MS-like condition. This gives a rationale of why
patients may perceive benefit from taking cannabis and supports
the establishment of a clinical trial to assess the benefit of medical
cannabis in MS," Lorna Layward, head of research of the
Multiple Sclerosis Society of Great Britain and Northern Ireland,
said.
In the study, led by David Baker of University College in London,
the researchers injected THC, other cannabinoid receptor agonists
and antagonists into mice with CREAE. Layward said it was now
up to drug companies to develop compounds that mimicked
cannabis but avoided the side-effects experienced by cannabis
smokers. The scientists cautioned the research is in the
preliminary stages; whether similar results can be obtained in
large-scale human studies is unknown.
(Sources: UPI of 2 March 2000, Reuters of 2 March 2000; PA
News of 2 March 2000)
3.
Science: Smoking marijuana my increase risk of heart attack
Smoking marijuana significantly increases the risk of a heart
attack for middle-aged and elderly users during the first hour after
using the drug, researchers reported on 2 March. They said they
were not sure whether the marijuana itself or other components of
smoke such as carbon monoxide were responsible for it.
The study by Dr. Murray Mittleman, a professor at Harvard
Medical School and director of cardiovascular epidemiology at
Beth Israel-Deaconess Medical Centre, and colleagues were
being presented at an American Heart Association (AHA)
conference in San Diego. The heart attack risk was 4.8 times
higher during the first hour following marijuana use than it was
during times of non-use. In the second hour, the relative risk
dropped to 1.7.
"These effects may pose significant risk, especially in people with
unrecognised coronary disease," Mittleman said. Mittleman's
research team collected information from 3,882 people who had
heart attacks. Of that group, 124 were identified as current
marijuana users, including 37 who said they smoked the drug
within 24 hours before their heart attack and nine who reported
smoking pot within an hour of their first symptoms.
The increased risk is nowhere near what is seen with other drugs -
- like the 25-fold spike in heart attack risk from cocaine -- and
may not even be as dangerous as taking a jog might be for a
sedentary person. But, Mittleman, says, "The risk is there. It's
real." Other studies have shown that younger marijuana smokers
are not at a greater risk for heart attacks.
(Sources: Reuters of 2 March 2000, UPI of 2 March 2000, AP of
2 March 2000)
4.
News in brief
***USA:
A panel of the state Medical Quality Assurance Commission of
Washington will consider whether to make anyone suffering
certain debilitating symptoms eligible to legally use marijuana for
medical purposes. Dr. Rob Killian is petitioning the board to add a
list of symptoms rather than specific diseases. The list suggested
by Killian includes: gastrointestinal symptoms such as nausea,
vomiting, anorexia, appetite loss and cramping; neurological
symptoms such as seizures, muscle spasms and spasticity; mood
disorders, including insomnia and post-traumatic stress disorder. A
final decision is expected on 2 June. (Source: Seattle Times of 2
March 2000)
5.
ONE YEAR AGO:
- World: U.N. report encourages research into the medical use of
cannabis
- Canada: Health Minister orders clinical trials
- Great Britain: Introduction of a bill for the medical use of
cannabis in Parliament
- USA: Introduction of a bill for the medical use of marijuana in
Congress
TWO YEARS AGO:
- The Netherlands: Marinol available
- USA: Resolution of the Judiciary Committee of the House of Representatives
against medical use of cannabis
(More at the ACM-Bulletin archive: http://www.acmed.org)
Association for Cannabis as Medicine (ACM)
NEW: Arnimstrasse 1a
NEW: D-50825 Cologne
Germany
Phone: +49-221-912 30 33
Fax: +49-221-130 05 91
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