A daily dose of the Ginkgo biloba extract EGB 761 may help to protect brain cells from damage caused by a stroke, new research suggests.

Sylvain Doré and colleagues from John Hopkins University conducted a study in normal mice and HO-1 knockout mice, mice which lack the HO-1 gene. HO-1 acts as an antioxidant and has been shown to have a protective effect against inflammation in animal models. The researchers believed that the protective effects of the Ginkgo biloba extract were due to its enhancement of HO-1 production.

The mice were given 100 mg/kg of EGb 761 extract each day for seven days prior to inducing a stroke in the animals. After the stroke, the animals were tested for neurological function and brain cell damage. Neurological function was assessed before stroke induction and 1, 2, and 22 hours following induced-stroke.

Results showed normal mice which were treated with EGb 671 prior to stroke had 50.9% less neurological dysfunction and 48.2% less brain damage than untreated mice. No effects were seen in the HO-1 knockout mice, thus suggesting that the researchers' theory was correct.

In a second study by the group, EGb 671 was shown to significantly reduce brain cell damage when administered 5 minutes and 4.5 hours after induced stroke.

"Our results suggest that some element or elements in ginkgo actually protect brain cells during stroke," said Doré in a news release issued by Johns Hopkins University. "If further work confirms what we've seen, we could theoretically recommend a daily regimen of ginkgo to people at high risk of stroke as a preventive measure against brain damage."

Saleem S, Zhuang H, Biswal S, Christen Y, Doré S. Ginkgo biloba extract neuroprotective action is dependent on heme oxygenase 1 in ischemic reperfusion brain injury. Stroke. Published online before print October 9, 2008, doi: 10.1161/STROKEAHA.108.523480

News release: Mouse studies suggest daily dose of ginkgo may prevent brain cell damage after a stroke. Johns Hopkins Medicine Website. October 9th 2008.