The effects of saikosaponin on macrophage functions and lymphocyte proliferation.

The effects of saikosaponin-d (ssd), isolated from Bupleurum radix, on phagocytic functions of mouse peritoneal macrophages were investigated after treatment in vitro. The macrophages treated with ssd showed a significant increase in PMA-induced chemiluminescence. An increase in phagocytosis was detected after treatment with saikosaponin-b2 (0.1 microM) for 24 h in vitro, while a suppression of phagocytosis was observed following treatment with saikosaponins (0.5 microM). Treatment with ssd markedly increased the random migration of resident peritoneal macrophages, but did not affect the migration towards FMLP. We further investigated the effect of ssd on proliferative responses of spleen cells and found that ssd, which itself has no mitogenic activity, decreased spleen cell proliferative response to T-cell mitogen, but increased the response to B-cell mitogen.