Tumor necrosis factor eliciting fractions separated from Pseudostellaria heterophylla

Tumor necrosis factor (TNF) could be induced in the serum of ICR mice bearing Ehrlich ascites tumor (EAT) cells by the i.v. administration of antitumor fractions (PH-I A, PH-I B, PH-I C, PH-I Ca, PH-I Cb) separated from the roots of Pseudostellaria heterophylla. TNF could also be detected in the ascitic fluid of EAT-bearing mice 2 h after i.v. injection with PH-I C, PH-I Ca or PH-I Cb. The proliferation of EAT cells was found to be significantly suppressed after the administration of these fractions. Our results suggest that the antitumor activity of P. heterophylla may be related, at least in part, to its capacity to induce TNF production in vivo. The strongest TNF eliciting and antitumor activity was found in the PH-I Cb fraction which is an acidic polysaccharide or proteoglycan with molecular weight of approximately 5000.