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.
http://patients4medicalmarijuana.wordpress.com/2010/04/30/topical-cannabis-healing-salve/