Modification of radiation response in mice by ginsenosides, active components of Panax ginseng

We performed this study to determine the effect of extract of whole ginseng and ginsenosides (total saponin, panaxadiol and panaxatriol) on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of mice irradiated with high- and low-doses of gamma-radiation. The radioprotective effect of ginseng was compared with the effect of diethyldithiocarbamate (DDC). The jejunal crypts were protected by pretreatment with extract of whole ginseng (i.p.: 50 mg/kg of body weight at 12 and 36 hours before irradiation, p < 0.005). Extract of whole ginseng (p < 0.005), total saponin (p < 0.01) or panaxadiol (p < 0.05) administration before irradiation (i.p.: 50 mg/kg of body weight at 12 and 36 hours before irradiation) resulted in an increase in the formation of the endogenous spleen colony. The frequency of radiation-induced apoptosis in the intestinal crypt cells was also reduced by pretreatment with extract of whole ginseng (p < 0.05), total saponin (p < 0.005) or panaxadiol (p < 0.05) (i.p. at 12 and 36 hours before irradiation). The radioprotective effect on the jejunal crypts and apoptosis in the DDC-treated group appeared similar to that in the ginseng-treated groups. Treatment with DDC showed no significant modifying effects on the formation of the endogenous spleen colony. In the experiment on the effect of ginsenosides, the result indicated that panaxadiol might have a major radioprotective effect. Although the mechanisms of this inhibitory effect remain to be elucidated, these results indicated that ginseng might be a useful radioprotector, especially since it is a relatively nontoxic natural product. Further studies are needed to better characterize the protective nature of ginseng extract and each ginsenoside.