[Activation of macrophages with Hochu-ekkito].

We attempted to analyse the mode of action of Hochu-ekkito on host defense mechanism, especially the effect of the drug on macrophage activation. Peptone-induced murine peritoneal exudate macrophages were incubated with/without Hochu-ekkito and interferon-gamma (IFN-gamma) for 16 hours at 37 degrees C, and then the supernatants harvested were assayed for the activities of TNF, IL-1 and prostaglandin E2. Cytotoxic activity of the macrophages against 51Cr-labeled EL-4 tumor cells was also assayed. It was found that Hochu-ekkito rendered macrophages cytotoxic against EL-4 cells. Hochu-ekkito also augmented the production of TNF, IL-1 or Prostaglandin E2 from macrophages. Synergistic effect of IFN-gamma for augmenting production of TNF or cytotoxic activity was noted. These results suggested that Hochu-ekkito activated macrophages directly in vitro.