Pubdate: Mon, 28 Feb 2000
Source: United Press International
Copyright: 2000 United Press International


NEW YORK - The chemical in marijuana that produces a
"high" has shown promise as a weapon against deadly brain tumors,
Spanish researchers have shown in early research.

In the study on rats a research team from Complutense University and
Autonoma University in Madrid found that marijuana's active ingredient
- -- called THC -- killed tumor cells in advanced cases of glioma, a
quick-killing cancer for which there is currently no effective
treatment. But, the scientists stress, it is unlikely that lighting up
a joint will do anything to prevent or cure cancer.

Lead researcher Manuel Guzman says he hopes to start studies in humans
in about a year.

Guzman says, "we observed a very remarkable growth inhibiting

Also, about one third of the treated rats lived "significantly longer"
than those given no drug, some up to about three times as long.

He injected the active compounds -- called cannabinoids -- directly
into the brain cancers.

Guzman, who is with Complutense University, says that the current
experiment, published in the March issue of Nature Medicine, tested
THC at very low doses and at a late stage, when untreated mice were
already starting to die.

He predicts that THC should work better if given earlier.

The scientists decided to test the marijuana drug in brain tumors
after laboratory studies showed that THC killed glioma cells while
leaving normal brain cells unharmed.

Researchers are not sure why, but Guzman's team says the drug caused a
buildup of a fat molecule called ceramide, which provoked a death
spiral in cancer cells.

The scientists say, "These results may provide the basis for a new
therapeutic approach for the treatment of malignant gliomas."

Asked if this work suggests that smoking pot may be an effective way
to fight or prevent cancer, Guzman says no. "When one smokes, only a
small part of the cannanbinoids are expected to reach the tumor," he

Pharmacologist Daniele Piomelli, a marijuana researcher who was not
involved with the Spanish study, was more emphatic. His answer was,
"No, with a capital letter."

"It is very important that the public does not get the impression that
from smoking pot cancer may be cured," says Piomelli, who is concerned
that cancer patients may learn about the study and decide to pass up
proven therapies in place of a joint.

"Lives are at stake here," he says.

Piomelli wrote a commentary on the Spanish research for Nature

Piomelli says that this is the first convincing study to show that a
marijuana-based drug treatment may combat cancer. If the drug works as
well in humans, he says, "Then this will be a paper of great

But, he points out that it will take a lot of testing, both in animals
and in people, to prove it is effective.

He says, "A lot of research in rats and mice didn't pan

Several laboratories are exploring the potential of compounds from
marijuana for treatment of such conditions as multiple sclerosis,
excessive weight loss related to AIDS or cancer and pain, he says.

Scientists are also trying to develop drugs that deliver therapeutic
benefits without unwanted side effects, such as the "high" and
amnesia, says Piomelli, who is with the University of California, Irvine. 
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