Antitumor Activity of Methanol Extract from Roots of Agrimonia pilosa LEDEB.

To evaluate the antitumor activity of Agrimonia pilosa LEDEB., the effects of the methanol extract from roots of the plant (AP-M) on several transplantable rodent tumors were investigated. AP-M significantly prolonged the life span of S180-, Meth-A fibrosarcoma- and MM-2 mammary carcinoma-bearing mice by intraperitoneal (i.p.) pre- or postmedication. AP-M also inhibited the growth of S-180 solid type tumor. On the other hand, the prolongation of life span induced by AP-M on S-180 ascites type tumor-bearing mice was markedly minimized or abolished by the pretreatment of cyclophosphamide. AP-M showed considerably strong cytotoxicity on MM-2 cells in vitro, but the effect was diminished to one-tenth by the addition of serum to the culture. Against the host animals, the peripheral white blood cells in mice were significantly increased from 2 to 5 days after the i.p. injection of AP-M. On 4th day after the injection of AP-M, the peritoneal exudate cells which possessed the cytotoxic activity on MM-2 cells in vitro were also increased to about 5-fold those in the non-treated control. The spleen of the mice was enlarged, and the spleen cells possessed the capacity to uptake 3H-thymidine. However, AP-M did not show direct migration activity like other mitogens against spleen cells from non-treated mice. These results indicate that the roots of Agrimonia pilosa contain some antitumor constituents, and possible mechanisms of the antitumor activity may be some host-mediated actions and direct cytotoxicity.