The induction of cytokine gene expression in murine peritoneal macrophages by Pseudostellaria heterophylla.

We have previously shown that a mitogenic fraction (PH-I) separated from Pseudostellaria heterophylla (P. heterophylla) could act as a priming agent for the release of tumor necrosis factor-alpha (TNF-alpha) in mice. In the present study, PH-I was further purified by gel filtration chromatography and the resulting three fractions (PH-I A, PH-I B and PH-I C) were assessed for the induction of TNF-alpha, interleukin-1-alpha (IL-1-alpha) and IL-1-beta gene expression in mice by enzyme-linked immunosorbent assay and polymerase chain reaction. It was found that fraction PH-I C from P. heterophylla was the most potent priming fraction among the three fractions for the induction of TNF-alpha in serum and the TNF-alpha mRNA in murine macrophages. Moreover, all three fractions were found to increase the expression of IL-1-alpha mRNA while PH-I C showed the most potent activating effect on the expression of IL-1-beta mRNA.