Inhibitory effects of a new iridoids, patridoid I and II on TNF, iNOS and COX-2 expression in cultured murine macrophages

Possible role of anti-inflammatory effects of a new iridoids, patridoid I. II and II-A which were isolated from Patrinia saniculaefolia. examined by assessing their effects on tumor necrosis factor $\alpha$ (TN F$\alpha$) and 2 enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in the lipopolysaccaride (LPS)-stimulated murine macrophage-like cell line RAW 264.7. Among them. patridoid II consistently inhibited the production of TNF$\alpha$ and NO production in a dose dependent manner. But patridoid I and patrioid ll isomer palrioid ll-A. these compounds very weakly inhibited NO producion. Moreover. treatment of macrophage with these compounds, the decrease in NO products was accompanied by a decrease in iNOS protein level as assessed by Western Blot. But these compounds did not affect COX-2 protein expression in LPS-stimulated macrophage. Our results suggest that patridoid ll could become a leading compound for developing a novel of anti-inflammalory drugs.