The herb Gingko biloba may reduce the amount of brain damage caused by a stroke
Ginkgo biloba as a standardized herbal extract is prescribed in several countries particularly for its medicinal properties in the brain. It protects neurons (brain nerve cells) from damage caused by free radical production. The current study was conducted by Johns Hopkins researchers finding a protective effect by Ginkgo biloba against the brain damage that occurs after a stroke.
"Ginkgo has long been touted for its positive effects on the brain and is even prescribed in Europe and Asia for memory loss," he stated. "Now we have a possible understanding for how ginkgo actually works to protect neurons from damage." The study is published online ahead of print in the October 9, 2008 issue of the journal Stroke, a journal of the American heart Association.
The scientists gave a group of the mice Ginkgo biloba extract or an inert substance to mice for seven days before inducing a stroke by blocking the middle cerebral artery. The researchers used normal mice as well as a strain that lack the gene that produces heme oxygenase-1 (HO-1), which has been shown to have an antioxidant effect as well as help protect against inflammation.
Tests of brain function and damage 1, 2 and 22 hours post-stroke revealed that pretreatment with ginkgo reduced neurologic dysfunction and damaged areas by approximately half compared to untreated mice, however, this effect was not seen in mice lacking HO-1. In other experiments, ginkgo was shown to elevate HO-1 levels, thereby increasing antioxidant activity to reduce free radical damage in the stroke-affected regions of the brain.
"It's still a large leap from rodent brains to human brains but these results strongly suggest that further research into the protective effects of ginkgo is warranted," Dr Doré, one of the participating researchers at Johns Hopkins commented. "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."