Antimetastatic and immunomodulating properties of a new herbal prescription, Bojung-bangam-tang.

We investigated the antimetastatic effect of Bojung-bangam-tang, a new herbal prescription, on liver metastasis by the inoculation of colon 26-L5 carcinoma cells into the portal vein. Oral administration of Bojung-bangam-tang for 15 days from day 7 before tumor inoculation significantly inhibited liver metastasis in a dose-dependent manner. Bojung-bangam-tang enhanced the mitogenic activity of BALB/c whole splenocytes induced by various mitogenic stimuli. Oral administration of Bojung-bangam-tang, by itself, could not induce the production of interleukin (IL)-12 or IFN-gamma by macrophages, but enhanced the potential of macrophages to produce cytokines in response to lipopolysaccharide (LPS). Experiments using macrophage- or natural killer (NK) cell-deficient mice revealed that the antimetastatic effect of Bojung-bangam-tang is mediated by macrophages rather than NK cells. Bojung-bangam-tang caused a marked increase of production of Th1 cytokine (IFN-gamma) and decrease of production of Th2 cytokine (IL-4) by splenocytes stimulated with concanavalin A (Con A). These results indicated that oral administration of Bojung-bangam-tang inhibited the liver metastasis of colon 26-L5 cells through a mechanism leading to a Th1 dominant immune state and activation of macrophages. Thus, Bojung-bangam-tang may be useful for the prevention of cancer metastasis. Copyright 2002 Elsevier Science B.V.