Activation of murine peritoneal macrophages by intraperitoneal administration of a traditional Chinese herbal medicine, xiao-chai-hu-tang (Japanese name: shosaiko-to).

Macrophage activation by a traditional Chinese herbal medicine, xiao-chai-hu-tang (Japanese name: shosaiko-to), was investigated. Intraperitoneal (i.p.) administration of shosaiko-to into (BALB/c x DBA/2)F1 mice resulted in marked activation of macrophages with respect to phagocytic and lysosomal enzyme activities (acid phosphatase and N-acetyl-beta-D-glucosaminidase) compared with the control. The maximal responses were induced by an i.p. injection of 3 mg shosaiko-to 4 days previously. Enhanced activities induced by shosaiko-to were also seen in C3H/HeJ mice, which is a non-responder strain to bacterial lipopolysaccharide (LPS). Significant macrophage accumulation in the peritoneal cavity and increased lysosomal enzyme activities were observed in mice injected with shosaiko-to. Shosaiko-to exhibited significant cytostasis-inducing activity. In addition, the administration of shosaiko-to led to a moderate expression of Ia antigen on the surface of peritoneal macrophages. These results suggest that shosaiko-to is a potent macrophage activator.