Inflammation is considered the root cause of various inflammatory diseases, including cancers. Decursinol angelate (DA), a pyranocoumarin compound obtained from the roots of Angelica gigas, has been reported to exhibit potent anti-inflammatory effects. In this study, the anti-inflammatory effects of DA on the MAP kinase and NFκB signaling pathways and the expression of pro-inflammatory cytokines were investigated in phorbol 12-myristate 13-acetate (PMA)-activated human promyelocytic leukemia (HL-60) and lipopolysaccharide (LPS)-stimulated macrophage (Raw 264.7) cell lines. PMA induced the activation of the MAP kinase-NFκB pathway and the production of pro-inflammatory cytokines in differentiated monocytes. Treatment with DA inhibited the activation of MAP kinases and the translocation of NFκB, and decreased the expression and exogenous secretion of IL-1β and IL-6. Furthermore, LPS-stimulated Raw 264.7 cells were found to have increased expression of M1 macrophage-associated markers, such as NADPH oxidase (NOX) and inducible nitric oxide synthase (iNOS), and the M2 macrophage-associated marker CD11b. LPS also activated pro-inflammatory cytokines and Erk-NFκB. Treatment with DA suppressed LPS-induced macrophage polarization and the inflammatory response by blocking Raf-ERK and the translocation of NFκB in Raw 264.7 cells. Treatment with DA also inhibited the expression of pro-inflammatory cytokines, such as IL-1β and IL-6, NOX, and iNOS in Raw 264.7 cells. These results suggest that DA has the potential to inhibit macrophage polarization and inflammation by blocking the activation of pro-inflammatory signals. These anti-inflammatory effects of DA may contribute to its potential use as a therapeutic strategy against various inflammation-induced cancers.
Keywords: MAP kinase; NFκB; cytokines; decursinol angelate; inflammation.