Effects of Shiranuhi flower extracts and fractions on lipopolysaccharide-induced inflammatory responses in murine RAW 264.7 cells

Objective: In this study, we evaluated the anti-inflammatory effect of Shiranuhi flower in RAW 264.7 cells. Methods: The effects of the extracts and solvent fractions on cell viability and LPS-induced inflammatory responses were investigated in RAW 264.7 cells. Results: The results showed that the ethyl acetate fraction (HEF) significantly decreased NO production in RAW 264.7 cells; however, cell viability was not affected. In addition, ELISA assay revealed that HEF significantly inhibited the productions of PGE(2), TNF-alpha, and IL-6. As well, using Western blot analysis, it was observed that HEF significantly reduced the expression levels of iNOS and COX-2 in a dose dependent manner. Furthermore, we detected a reduced phosphorylation of mitogen-activated protein kinases such as p38, JNK, and ERK1/2. This indicates that HEF regulates LPS-induced inflammatory responses, at least in part, via suppressing the MAPK signaling pathway. Correlation analysis also showed that anti-inflammatory activities were highly correlated to antioxidant activities in this study. Characterization of the Shiranuhi flowers for flavonoid contents using HPLC showed varied quantity of narirutin and hesperidin. Conclusion: Overall, the results demonstrate that HEF may be a potential anti-inflammatory agent. In addition, our findings contribute to understanding the molecular mechanism underlying the anti-inflammatory effect of Shiranuhi flower.