Chunghyuldan (Daio-Orengedokuto in Japanese) (CHD) has been used as an antihyperlipidemic and antiischemic agent in Korea. To evaluate in vitro the efficacy of Chunghyuldans (CHDs) metabolized with and without human intestinal microflora against brain ischemia, we investigated its anti-inflammatory effect on LPS-induced RAW264.7 cells. Both metabolized CHD (MCHD) and CHD showed antioxidant activities in vitro, and inhibited nitric oxide (NO) and prostaglandin E2 (PGE2) productions in lipopolysaccharide (LPS)-induced RAW264.7 cells. These also inhibited enzyme activities and protein expressions of inducible NO synthase and cyclooxygenase-2 in LPS-induced RAW264.7 cells. MCHD-inhibitory activity against NO and PGE2 productions in LPS-induced RAW264.7 cells was more potent than those of CHD. These results suggest that CHD may show potent anti-inflammatory activity in vivo and can improve brain ischemia.