Inhibitory Effects Of JEUD-38, A New Sesquiterpene Lactone From Inula Japonica Thunb, On NO Production By RAW264.7 Cells

Objective:Inula species has been demonstrated in terms of anti-tumor, anti-inflammatory, antibacterial, prevention of hepatitis and protection of liver, and the prevention and treatment of diabetes have better biological activity, with high medicinal value. Through previous study, we isolated 21 compounds from Inula japonica.Among them named 1-oxo-4αH-eudesma-5(6),11(13)-dien-12,8β-olide(JEUD-38) is a new sesquiterpene lactone.JEUD-38 has potent inhibitory effect against nitric oxide(NO) production in RAW264.7 cells by us previous study in order to clarity it’s mechanism, we evaluated the effect of JEUD-38 on nitric oxide synthase(i NOS) expression, nuclear factor-kappa-B(NF-kB) activation and mitogen-activated protein kinase expression(MAPKs) phosphorylation.Methods:Using lipopolysaccharide(LPS)-induced murine RAW264.7 macrophage cells were used in this study.1. The use of experimental research MTT to measure the JEUD-38 of cytotoxic effect on RAW264.7 cells; determine cell toxicity concentration range of compounds.2. The use of Griess reagent to find out the inhibition effect of JEUD-38 on NO production to detection the release of NO.3. Using the Western blot method research JEUD-38 on LPS-induced RAW264.7 cells against NO production mechanism; by detecting i NOS and its upstream of two protein pathways: NF-kB pathway and MAPKs phosphorylation level of the pathway.Results:JEUD-38 exhibits anti-inflammatory properties, can significantly reduce the LPS induced NO production, and concentration-dependent manner inhibited LPS-induced protein expression of i NOS. In the mechanism study found that JEUD-38 inhibited LPS-induced translocation of NF-kB, supressed phosphorylation and degradation of IkB-a in RAW264.7 cells. Meanwhile JEUD-38 inhibited LPS-stimulated MAPKs phosphorylation have shown a dose-dependent manner, the MAPKs including theextracellular signal-regulated kinase 1/2(ERK1/2) in, c-Jun N-terminal kinase(JNK) and p38.Conclusions:JEUD-38 inhibited NO production and iNOS expression through inhibiton of NF-?B and MAPK pathway. These results suggest that, JEUD-38 has good prospects in the prevention and treatment of inflammatory diseases. It is expected to become a promisiong candidate for therapy of inflammatory diseases.