Pubdate: Fri, 09 Sep 2005
Source: Mail and Guardian (South Africa)
Copyright: Mail & Guardian, 2005
Contact:  http://www.mg.co.za/mg/
Details: http://www.mapinc.org/media/254
Author: Alok Jha
Bookmark: http://www.mapinc.org/mmj.htm (Cannabis - Medicinal)

CANNABIS FOR SLIMMERS

Scientists have unveiled an unlikely weapon in the battle against the 
bulge: cannabis. More specifically, one of its key ingredients, which has 
been found to suppress appetite.

Anyone who has ever inhaled will know the feeling: an inescapable desire to 
eat everything in sight, a state called the munchies. It stems from the 
action of tetrahydrocannabinol (THC), one of the active ingredients in 
cannabis, on specific appetite-control receptors in the brain. The chemical 
also causes the body to lay down more fat.

But Roger Pertwee, a neuro-pharmacologist at Aberdeen University, Scotland, 
said at the British Association for the Advancement of Science's Festival 
of Science in Dublin, that there is more to the cannabis story.

"We've discovered, to our surprise, that cannabis, as well as containing a 
drug that boosts appetite, contains a drug which has a blocking effect," 
said Pertwee. "The work so far has been working with tissue. We've yet to 
see what this drug does when we give it to a whole organism, and what it 
does when we give it to humans."

The drug, known as tetrahydrocannabivarin (THCV), works on the same 
receptors as THC, but has entirely the opposite effect. The research will 
be published in the British Journal of Pharmacology.

THCV is not the first appetite suppressant to be inspired by cannabis. The 
drug Rimonabant works by blocking the brain receptors that the body's own 
cannabinoid compounds - released when we comfort eat - attach themselves 
to. Because the cannabinoids do not reach the receptors in a person taking 
Rimonabant, they will feel less compulsion to eat.

Why THCV does not manifest itself to people who smoke cannabis is a 
mystery, but Pertwee said it might have something to do with the 
proportions of the various ingredients in the drug. "The relative 
proportions of THC and THCV vary from cannabis to cannabis," he said.

"There is a large amount of THCV in Pakistani cannabis, which is the one 
used to make a medicine called 'tincture of cannabis" That contains about 
equal amounts of THC and THCV." Pertwee said that there were several 
promising medicinal compounds to be derived from cannabis, both for 
boosting the effects of the body's own cannabinoids and for blocking them.

Boosting the cannabinoids could bring pain relief, for example, and relieve 
spasms for sufferers of multiple sclerosis. Pertwee added that there was 
also evidence that the compounds had a protective effect against cancer.

As well as controlling appetite, developing drugs that block the body's 
cannabinoids could help people to quit smoking by stopping nicotine having 
any effect on the brain.
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MAP posted-by: Jay Bergstrom