Pubdate: Sat, 09 Jun 2007
Source: San Francisco Chronicle (CA)
Page: B - 3
Copyright: 2007 Hearst Communications Inc.
Contact:  http://www.sfgate.com/chronicle/
Details: http://www.mapinc.org/media/388
Author: Kavita Mishra, Chronicle Staff Writer
Bookmark: http://www.mapinc.org/mmj.htm (Marijuana - Medicinal)

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 a 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 for use 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. 
- ---
MAP posted-by: Richard Lake