09/06/2007 00:00:00
New frontier for medical cannabis -- topical pot
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New frontier for medical cannabis -- topical pot
Anti-inflammatory traits helped heal skin of mice in study.
Skin allergies may be the next reason to use marijuana -- a topical
form, at least.
Scientists have long suspected that marijuana, used for recreational
purposes and to help fight chronic pain, nausea and even some mental
disorders like anxiety and depression, also had anti-inflammatory
effects in the body.
Now they think they know why.
In a study published in the current issue of the journal Science,
researchers show exactly how they think that works, elucidating how the
body's own cannabinoids, compounds that are similar to the ones found in
marijuana, reduce inflammation.
Mice had a harder time healing from wounds caused by ear tags used to
identify them when researchers blocked their internal cannabinoids, said
Dr. Meliha Karsak, lead author and scientist in molecular neurobiology
at the University of Bonn in Germany. Cannabinoids are involved in many
of the body's daily functions, scientists believe, but they're still
trying to figure out how.
Mice also healed faster from skin allergies with topical THC, the main
psychoactive ingredient in marijuana and other plants, she said.
Dr. Frank Lucido, a Berkeley physician who was not involved in the study
but regularly recommends medical marijuana, said the plant's
anti-inflammatory effects didn't surprise him. He has had patients who
say their psoriasis, an immune disease that affects the skin and joints,
and asthma get better when they smoke marijuana.
In the 1980s, scientists discovered receptors in the body that respond
to active compounds in cannabis, Karsak said. Once activated with THC
and other chemicals from marijuana, the receptors had effects
downstream, for instance changing a person's mood and perception. Since
then, two main receptors have been studied: One is more prevalent in the
central nervous system, the other in the periphery.
The one in the periphery seems to respond to cannabinoids in
inflammation and is found in cells of the immune system, said Dr. Donald
Abrams, a San Francisco General Hospital physician who has studied the
effects of marijuana use in HIV patients.
"Most people have believed for some time that the cannabinoid system is
involved in modulating the immune system," he said.
But experts say they're uncertain how such a controversial chemical
could reach the hands of patients with skin allergies.Scientists would
have to develop a product that had more effect on the cannabinoid
receptors in the periphery than in the brain and spinal cord where the
psychotropic effects would be more common, said Dr. Ben Cravatt, a
researcher in the study and professor in cell biology at the Scripps
Research Institute in La Jolla.
Karsak, however, said the experiments on mice showed that the dose of
THC in a topical cream for humans would be small enough to avoid
psychotropic effects. She also doubted that people could extract enough
THC from the cream to be used as a recreational drug.
Contact with substances like poison oak can easily cause a blistering,
allergic skin reaction, said Dr. Stephen Katz, a dermatologist and head
of the National Institute of Arthritis and Musculoskeletal and Skin
Diseases. Topical steroids and other medications work well against
dermatitis, he said, adding that he didn't think enough was known about
cannabinoids and skin reactions to create a medication from cannabinoids.
Dr. Mark Dahl, chairman of dermatology at the Mayo Clinic College of
Medicine in Arizona, cautioned patients against using marijuana for
their skin allergies. "I doubt that if they had a rash, rubbing their
marijuana plant would make much difference," he said.
California is the only state to allow physicians to recommend marijuana
for any medical purpose, unlike other states that dictate its use in
specific ailments, Lucido said.
Seventy-five percent of the patients Lucido treats with marijuana
complain of chronic pain. The rest have post-traumatic stress disorder,
depression, anxiety, headaches or muscle spasms, like in patients with
multiple sclerosis.
He said he hoped the study would convince politicians to invest in more
research about cannabinoids and help get more states to pass medical
marijuana laws.
This article appeared on page B - 3 of the San Francisco Chronicle
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/06/09/POT.TMP
Posted by The Legalise Cannabis Alliance http://www.lca-uk.org/
Source:
http://www.ukcia.org/news/shownewsarticle.php?articleid=12597
Author:
San Francisco Chronicler via UKCIA
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