Effects of Shiranuhi flower extracts and fractions on lipopolysaccharide-induced inflammatory responses in murine RAW 264.7 cells
Abstract 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 PGE2, TNF-α, 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.