Luteolin 5-O-glucoside, a major flavonoidfrom Cirsium maackii, possesses anti-inflammatory activity. Luteolin 5-O-glucoside inhibits LPS-induced NO production and t-BHP-induced ROS generation. Luteolin 5-O-glucoside suppresses the expression of iNOS and COX-2 in macrophages.In Vitro: Luteolin 5-O-glucoside, at a non-toxic concentration, inhibits LPS-induced NO production and t-BHP-induced ROS generation in a dose-dependent manner in RAW 264.7 cells. Luteolin 5-O-glucoside also suppresses the expression of iNOS and COX-2 in LPS-stimulated macrophages.