Antitumor Effects of the Partially Purified Polysaccharides from Antrodia Camphorata and the Mechanism of Its Action

Antrodia camphorata is a popular folk medicine that has attracted great attention due to its fame for antitumor activity against cancer. However, there is little information available about its action. In the present study , we purified a unique polysaccharide component from A. camphorata mycelia (AC-PS) and found that it has pronounced anti-tumor effects on both in vitro and in vivo model. Our results showed that AC-PS alone did not show any direct cytotoxic effect to human leukemic U937 cells, even at high concentration (200 mug/ml). However, it could inhibit the proliferation of U937 cells via activation of mononuclear cells (MNCs). Treatment of U937 cells with AC-PS-stimulated- MNC-CM could significantly inhibit its proliferation with 55.3% growth inhibition rate. The in vitro antitumor activity was substantiated by the in vivo therapeutical study of AC- PS in sarcoma 180-bearing mice. Intraperitoneal and oral administration of AC-PS, 100 and 200 mg/kg significantly suppressed the tumor growth with the inhibition rate of 69.1% and 58.8%, respectively. In vivo studies also showed that several immunoparameters, such as the spontaneous proliferation of spleen cells, after AC-PS administration, were two-fold higher than in control mice. Furthermore, the cytolytic activity of spleen cells also increased from 9.8 +/- 1.1% in control mice to 34.2 +/- 5.5% and 48.2 +/- 2.5%, after oral and intraperitoneal treatment , respectively. Besides, the mice serum interleukin-12 levels increased significantly by AC-PS treatment. Considering all these results, it is suggested that AC-PS elicit its anti-tumor effect by promoting a Th 1-dominant state and killer activities. (C) 2004 Elsevier Inc. All rights reserved.