Researchers conducted a study in which two groups of mice received an oral dose of 100 milligrams per kilogram of EGb 761 ginkgo biloba once per day. At the start of the study, all of the mice - including a control group of mice not dosed with gingko biloba - had been tested for general brain function and for signs of brain damage. These included weakness of front limbs, the inability to bear weight and lack of spontaneous motor movement.

In one of the groups of ginkgo-treated mice, the researchers knocked out the gene that regulates the production of the HO-1 enzyme, a known antioxidant that has been shown in animal tests to protect against inflammation. A second group of the ginkgo-treated mice was left genetically unmodified. After seven days, they blocked an artery leading to one side of the brain to deliberately induce an ischemic stroke in all of the mice, including those that had not received doses of ginkgo biloba. At 1, 2 and 22 hours following the induced stroke, they retested brain function.

According to their findings, which were published in the journal Stroke, the mice that had received ginkgo biloba extract suffered 50.9 percent less neurological dysfunction than either the untreated mice or the mice in which the HO-1 antioxidant had been knocked out. In addition, the damaged areas in the brains of the normal gingko-treated mice were 48.2 percent smaller than in the other mice.

The researchers believe that gingko is responsible for increasing the levels of HO-1, which then protects the brain from free radicals shown to concentrate at the site of an ischemic stroke. "Our results suggest that some element or elements in ginkgo actually protect brain cells during stroke," says researcher Sylvain Dore. "If further work confirms what we've seen, we could theoretically recommend a daily regimen of ginkgo to people at high risk of stoke as a preventive measure against brain damage."

News Release: Ginkgo reduces brain damage from stroke by 50 percent www.naturalnews.com  April 2, 2009