Flavonoids from Rhynchosia minima root exerts anti-inflammatory activity in lipopolysaccharide-stimulated RAW 264.7 cells via MAPK/NF-κB signaling pathway

Rhynchosia minima root, a folk herbal medicine in southern China, is used to relieve itch and swelling. In this study, we examined the anti-inflammatory property of an ethanol fraction (EEF6) from R. minima root on lipopolysaccharide (LPS)-induced RAW 264.7 cells, as well as its underlying mechanism. The compound composition of EEF6 was determined by high-performance liquid chromatography-mass spectrometry. The result showed that five flavonoids compounds, 2′,4′,5,7-tetrahydroxyisoflavone, genistein-8-C-glucopyranoside, tricin, genistein, and daidzein, were identified in EEF6. In addition, EEF6 exhibited potent anti-inflammatory ability against LPS-stimulated RAW 264.7 cells via MAPK/NF-κB signaling pathways by decreasing the secretion of nitric oxide (NO), interleukin (IL)-6, TNF-α, and monocyte chemotactic protein (MCP)-1, inhibiting the translocation of p65 from cytoplasm to nucleus, and suppressing the phosphorylation of ERK, JNK, and p38. These results indicated that EEF6 could be a promising ingredient for inflammation management.