The results of the present study clearly show that eupafolin derived from Artemisia princeps Pampanini exerts anti-inflammatory effects by inhibiting the production of NO and PGE2, as well as their upstream enzymes, iNOS and COX-2, at the protein level mainly through inhibition of JNK phosphorylation and NF-κB p65 and AP-1/c-fos activation in LPS-treated RAW264.7 cells (Fig 8); eupafolin also suppresses the LPS-induced ALI and paw inflammation in mice. This evidence concerns the gene PTGS2 and acute respiratory distress syndrome.