The interleukin-18 inhibitory activities of echinocystic acid and its saponins from impatiens pritzellii var. hupehensis

Abstract

Echinocystic acid (1), an echinocystic acid saponin, 2, and four of its ester saponins, 3 - 6, obtained from the active fraction of Impatiens pritzellii var. hupehensis, an traditional Chinese medicine for rheumatoid arthritis, were investigated for their effects on lipopolysaccharide (LPS)-induced interleukin (IL)-18 in human peripheral blood mononuclear cells. Three of them, 1, 2 and 6, showed obvious activity to inhibit the production of IL-18, especially the ester saponins with a sugar chain at C-28, 6. Structure-activity relationships are discussed in brief. © 2009 Verlag der Zeitschrift für Naturforschung, Tübingen.