Abstract
In this study, tomentosin, a sesquiterpene lactone was isolated from Inulae flos and its biological activities were investigated. The effects of tomentosin on the production of inflammatory mediators as well as on nuclear factor (NF)-κB and mitogen-activated protein (MAP) kinase activation were evaluated in RAW264.7 cells. Tomentosin decreased the production of nitric oxide (NO) and prostaglandin E2 (PGE2) by suppressing the protein expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2, respectively. Additionally, tomentosin reduced the release of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Tomentosin not only attenuated lipopolysaccharide (LPS)-induced NF-κB activation via the abrogation of inhibitory (I)κBα degradation and caused a subsequent decrease in nuclear p65 level, but it also suppressed the phosphorylation of MAP kinases (p38 and c-Jun N terminal kinase (JNK)). These results indicate that tomentosin exerts anti-inflammatory activities through the inhibition of inflammatory mediators (NO, iNOS, PGE2, COX-2, TNF-α, and IL-6) by regulating NF-κB activation and phosphorylation of p38/JNK kinases in macrophages, thus suggesting that tomentosin could be a potential agent for the treatment of inflammatory diseases.
