CXCL8 and rheumatoid arthritis: Malvidin-3-O-β glucoside, extracted from red grape skin extract powder, relieved RA symptoms by downregulating TNF-α, IL1, macrophage inflammatory protein 1a (MIP1a), IL-8, IL-6, NO, and NOx when a dose of 1, 10, and 100 μM was applied to human peripheral blood monocyte-derived macrophages for 24 h.