Induction of colony-stimulating factor(s) after administration of a traditional Chinese medicine, xiao-chai-hu-tang (Japanese name: shosaiko-to).

Colony stimulating factor (CSF)-rich serum was obtained from mice injected intraperitoneally (ip) with shosaiko-to, a traditional Chinese herbal medicine. Transfer of the CSF-rich serum into naive mice augmented the resistance against Listeria monocytogenes. A dose-dependent induction of CSF was observed in mice given shosaiko-to via intravenous route as well as via intraperitoneal route. Since the serum CSF induction was observed in both lipopolysaccharide (LPS)-responder C3H/He mice and LPS-non-responder C3H/HeJ mice, the effect of shosaiko-to seemed to be independent of possibly contaminating LPS. The level of serum CSF induced by shosaiko-to in athymic nude mice was similar to that in control euthymic mice, and the induction of CSF was completely blocked by the previous administration of carrageenan, a selective macrophage-blocker. In mice treated ip with shosaiko-to CSF activity was detected in the peritoneal cavity, the site of injection, and the time course was similar to that of serum CSF induction. In a bone marrow culture system, the composition of colonies formed by shosaiko-to-induced CSF was similar to that formed by standard GM-CSF. The CSF activity was scarcely affected by treatment of the sera with anti-M-CSF antibody. These results suggest that shosaiko-to augments the host defense by inducing mainly GM-CSF, and that CSF is produced by cells of macrophage lineage. In addition, it was shown that CSF could be induced even after oral administration of herbal medicines.