Radioprotective effects of two traditional Chinese medicine prescriptions: si-wu-tang and si-jun-zi-tang

We performed this study to determine the effect of Si-Wu-Tang, a basic prescription of traditional Oriental medicine as a blood-building decoction (Chinese medical concept: Bu-Xie), Si-Jun-Zi-Tang, a basic prescription as an energy tonic (Chinese medical concept: Bu-Qi) and its major ingredients on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of mice irradiated with high and low dose of gamma-irradiation. Si-Wu-Tang administration before irradiation protected the jejunal crypts (p < 0.0005), increased the formation of endogenous spleen colonies (p < 0.05) and reduced the frequency of radiation-induced apoptosis (p < 0.05). In an experiment on the effect of ingredients of Si-Wu-Tang, the result indicated that extract of Danggui and Baishaoyao might have a major radioprotective effect. The radioprotective effect of Si-Jun-Zi-Tang and its ingredients were not as significant as that of Si-Wu-Tang. Although the mechanisms of this inhibitory effect remain to be elucidated, these results indicate that Si-Wu-Tang might be a useful radioprotector, especially since it is a relatively nontoxic natural product. Further studies are needed to characterize better the protective nature of Si-Wu-Tang extract and its ingredients.