Effects of 3'-isovaleryl-4'-senecioylkhellactone from Peucedanum japonicum Thunberg on PMA-stimulated inflammatory response in A549 human lung epithelial cells.

Peucedanum japonicum Thunberg (PJT) has been used in traditional medicine to treat colds, coughs, fevers and other inflammatory diseases. The goal of this study was to investigate whether 3'-isovaleryl-4'-senecioylkhellactone (IVSK) from PJT has anti-inflammatory effects on lung epithelial cells. Anti-inflammatory effects of IVSK was evaluated using phorbol 12-myristate 13-acetate (PMA)-stimulated A549 cells and regular human lung epithelial cells as a reference. IVSK reduced the secretion of inflammatory mediators, interleukin (IL)-8 and monocyte chemoattractant protein-1 (MCP-1) and the mRNA expression of IL-6, IL-8, MCP-1 and IL-1β. Additionally, it inhibited the phosphorylation of IκB kinase (IKK), p65, Iκ-Bα and mitogen-activated protein kinases (MAPKs) p38, JNK, and ERK in A549 cells stimulated with PMA. Moreover, the binding affinity of activator protein-1 (AP-1) and nuclear factor-κB (NF-κB) was significantly reduced in the luciferase assay, and nuclear translocation was markedly inhibited by IVSK in the immunocytochemistry. These findings indicate that IVSK can protect against inflammation through the AP-1 and NF-κB pathway and could possibly be used as a lead compound for the treatment of inflammatory lung diseases.