Responses of inflammation signaling pathway by saucerneol D from elicitor-treated Saururus chinensis on pro-inflammatory responses in LPS-stimulated Raw 264.7 cell

This study confirmed the association with inflammation-related proteins, mediators, and cytokines using saucerneol D from Saururus chinensis leaf, a useful ingredient increased through elicitor treatment. To confirm the anti-inflammatory effect, saucerneol D were treated with lipopolysaccharide, which induces pro-inflammatory factors in Raw 264.7 cell. The pro-inflammatory influences were measured by dint of chemical assay and western blotting as well as ELISA. As a result, the content of saucerneol D was changed when eicitor was treated by various concentration (1.5, and 3 mg/mL) in S. chinensis leaves. In addition, the expression levels of hyaluronidase and pro-inflammatory-related factors [nitric oxide (NO), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2)] were regulated according to the saucerneol D content in the elicitor-treated and non-treated groups. Therefore, after confirming that saucerneol D has an inhibitory effect on pro-inflammatory-related factors, saucerneol D was adjusted by concentration and compared with the control substance to verify the efficacy. Saucerneol D was adjusted to a concentration that did not toxic to macrophages through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Saucerneol D controlled at various concentrations inhibited iNOS and COX-2 proteins. NO produced by iNOS activity, prostaglandin E₂ (PGE₂), an inflammatory mediator produced by COX-2 activity, and pro-inflammatory cytokines [interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α)] were significantly suppressed. Therefore, it was confirmed that saucerneol D, an active ingredient increased by the elicitor treatment, could be used as a functional material that controls inflammatory factors.