Ginkgo has protective effect against radiation damage

[nightowl]

Protective effect found for ginkgo against radiation damage


A report published in the October 11, 2009 issue of the International Journal of Low Radiation added evidence to a protective effect for Ginkgo biloba against radiation damage. Ginkgo biloba is a tree species whose leaves have been used for centuries in Chinese medicine. Ginkgo leaf extract contains antioxidant compounds called ginkgolides and bilobalides which help scavenge free radicals that attack nearly all components of the cell, including DNA.

In their article, Chang-Mo Kang of the Korea Institute of Radiological and Medical Sciences in Taegu and colleagues describe their use of an assay for radiation-induced programmed cell death (apoptosis) to evaluate the protective effect of ginkgo extract against radiation exposure that occurs during accidents or occupational overexposure. In one experiment, white blood cells from human donors aged 18 to 50 were treated with one of four concentrations of ginkgo extract or a 9 percent saline solution before being exposed to gamma rays.



The researchers found a significant dose-dependent reduction in apoptotic cells among those treated with ginkgo. While radiation-induced apoptosis occurred in nearly one third of irradiated cells not treated with ginkgo, the number declined to 5 percent or less in cells treated with the herb.

In another experiment, mice were treated with ginkgo extract or saline before and after receiving whole body ionizing radiation. Mice that did not undergo radiation served as controls. Examination of the animals' spleens found that treatment with ginkgo maintained organ size comparable with that of animals that did not receive radiation, while spleens in irradiated animals that did not receive ginkgo were significantly smaller.

In their discussion of the findings, the authors note that cell-damaging free radicals and reactive oxygen species can be generated in excess under numerous conditions, including exposure to environmental chemicals, specific drugs, and during normal aging.

"These results indicate that the radioprotective effects of ginkgo extracts administered prior to radiation are due to the OH radical scavenging activity," the authors write. "Therefore, ginkgo extract should be useful for the protection of radiosensitive organs against free radicals.