Radioprotective effects of ginsan through the stimulation hematopoiesis and antioxidant enzymes

An immunomodulator ginsan which was isolated from Panax ginseng showed the mitogenic activity, generation of LAK cells, and secretion of several cytokines. In the extended effort to search other immunostimulatory effects, we evaluated protective effects of in vivo injected Ginsan against irradiation, by measuring the recovery of CFU-S, and the functioning of bone marrow (BM) and spleen cells. Ginsan was found to significantly increase the number of BM cells, spleen cells, granulocytes macrophage-colony forming cells (GM-CFC), and the number of circulating neutrophils, lymphocytes and platelets in irradiated mice. In addition, it induced endogenous production of cytokines such as IL-1, IL-6, IFN-g and IL-12, which are required for hematopoietic recovery, and was able to enhance Th1 function while interfering with the Th2 response in irradiated mice. We demonstrated that the pretreatment with Ginsan protected mice from lethal effects of ionizing radiation more effectively than given immediately or after the irradiation. A significant increase of the survival of Ginsan-treated group (100mg/kg) from LD50/30 7.54 Gy of PBS-injection to 10.93 Gy was observed. Moreover, the levels of the antioxidant enzymes such as SODs, catalase and gluthathion peroxidase were increased 1.5-2 fold in ginsan treated mice compared to the irradiated mice. These findings indicate that ginsan may be a promising agent to be used in reducing the time needed for reconstituting of hematopoietic cells after irradiation treatment