In VitroAntiinflammatory Activity of a New Sesquiterpene Lactone Isolated fromSiegesbeckia glabrescens

A new sesquiterpene lactone was isolated from Siegesbeckia glabrescens as an inhibitor of nitric oxide and prostaglandin E 2 synthesis in the LPS‐activated RAW264.7 macrophage cell line. It dose‐dependently decreased the protein and mRNA levels of inducible nitric oxide synthase and cyclooxygenase‐2. Reporter gene assay revealed that the compound attenuated the LPS‐induced DNA transcriptional activity of nuclear factor‐kappa B (NF‐κB). In addition, it inhibited the nuclear translocation of the p65 subunit of NF‐κB by blocking the inhibitory kappa B‐α degradation. This compound from Siegesbeckia glabrescens might be beneficial for the treatment of inflammation‐related diseases. Copyright © 2011 John Wiley & Sons, Ltd.