Activation of Macrophage by PCSC22 Isolated from Poria cocos Sclerotium / 체질인류학회지

ABSTRACT

The sclerotium of Poria cocos Wolf, which grows on the roots of pine trees, has long been used as a sedative, diuretic, and anti-inflammatory agent. The accumulating data revealed that certain ingredients of the sclerotium of Poria cocos showed anti-tumor activities. Although the mechanism of anti-tumor activity is not known, the polysaccharides may potentiate the host defense mechanism through the activation of immune system. In the present study we show that PCSC22, a polysaccharide isolated from the sclerotium of Poria cocos with one percent sodium carbonate, significantly induces nitric oxide (NO). Immunohistochemical staining of inducible NO synthase (iNOS) showed that the increase of NO was due to the induction of iNOS production. To further study the mechanism responsible for the induction of iNOS gene expression, we investigated the effect of PCSC22 on the activation of p38 kinase, which is important in the gene expression of inflammatory cytokines including iNOS. Western blot assay showed that PCSC22 produced phosphorylation of p38 kinase. In conclusion, we demonstrate that PCSC stimulates macrophages to express iNOS gene through the activation of p38 kinase.