Ginkgo extract offers promise to cut stroke damage

By Will Dunham

WASHINGTON (Reuters) - Extract from the leaves of the ginkgo tree offers promise to minimize brain damage caused by a stroke, scientists said on Thursday.

Mice given daily doses of ginkgo biloba extract before having a stroke induced in the laboratory suffered only about half the damage as animals not given it, researchers at Johns Hopkins University in Baltimore wrote in the journal Stroke.

Mice who did not get ginkgo before a stroke but were given it five minutes after a stroke sustained nearly 60 percent less damage in the day after the stroke than those not given ginkgo. And mice given ginkgo 4-1/2 hours after a stroke had about a third less damage than those not given ginkgo.

The researchers said ginkgo may offer the same benefits in people -- which would be particularly important because not much can be done to protect the brain after a stroke.

"We tested the concept of preventive medicine by giving ginkgo before stroke and we showed protection," said Sylvain Dore of Johns Hopkins, who led the study.

"And the other thing we showed is the potential therapeutic application of ginkgo. So it was given after the stroke and we also showed protection," Dore said in a telephone interview.

Some stroke patients can benefit from a clot-busting drug called tissue plasminogen activator or tPA. But it can be given to patients only within about three hours of a stroke and only when doctors feel it would not worsen bleeding in the brain.

And tPA does not protect against the brain cell damage that occurs once blood flow is restored.