Pot Chemical May Curb Inflammation

Marijuana's active ingredient may curb inflammation and help
treat skin allergies.

That news comes from researchers including Meliha Karsak, PhD, and Thomas
Tuting, MD, of Germany's University of Bonn.

Marijuana's key compound, THC, is a type of chemical called a cannabinoid.
The brain contains two types of cannabinoid receptors.

Karsak and colleagues studied mice born with or without cannabinoid
receptors. The mice wore ear tags to identify them; those ear tags contained
nickel.

The mice without cannabinoid receptors were particularly likely to have
allergic skin reactions to the nickel in the ear tags.

The scientists reasoned that the mice's allergies may have been linked to
their lack of cannabinoid receptors.

Karsak's team tested that theory in several experiments.

First, they turned off cannabinoid receptors in healthy mice. Those mice
then became more likely to develop skin inflammation near their nickel ear
tags.

Next, the researchers exposed other mice with cannabinoid receptors to a
skin irritant. Some of the mice got THC shots after being exposed to the
irritant. Others got a THC skin lotion before and after exposure to the
irritant.

The THC shot and lotion both helped soothe the mice's inflamed skin.

"If we dabbed THC solution onto the animals' skin shortly before and
after applying the allergen, a lot less swelling occurred than normal,"
Tuting says in a University of Bonn news release.

In the journal Science, the researchers write that their study
"strongly suggests" that the body's cannabinoid system can help tame
inflammation and that THC skin lotions have "promising potential" for
treating skin allergies caused by contact with irritating chemicals.

However, the researchers didn't test the THC lotion on skin allergies in
people.

By Miranda Hitti
Reviewed by Louise Chang
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