Restoration of radiation injury by ginseng, 2

Some properties of the radioprotective substances in a ginseng extract that increased the 30-day survival ratio in irradiated mice were studied. Methanol-soluble fraction of the extract did not protect the irradiated animals. Acid or alkali (0.12 N) inactivated the extract at 600C. But the radioprotective activity was stable after heating the ginseng extract in physiological saline at pH 7 in a boiling-water bath for 15 min. The ginseng extract was separated into two fractions by CM-cellulose column chromatography. One of them (CM-A) was significantly efficacious at 5% level, and the other (CM-B) at 0.1% level with the doses proportional to their yields. CM-B, not containing saponin, was subjected to further purification, UV spectrum and a biuret test suggested the presence of protein in this fraction. The supernatant obtained after heating CM-B solution at pH 7 was separated into three fractions, namely G-I, G-II and G-III, by gel-chromatography with a Sephadex G-75 column. Both G-I (0.44 mg per animal) and G-III (0.84 mg, calculated dose) were significantly efficacious, but G-II (0.47 mg) was not. (author)