Alantolactone suppresses inducible nitric oxide synthase and cyclooxygenase-2 expression by down-regulating NF-κB, MAPK and AP-1 via the MyD88 signaling pathway in LPS-activated RAW 264.7 cells

► We assessed the anti-inflammatory effect of alantolactone in LPS-induced RAW 264.7 cells and primary peritoneal macrophages. ► Alantolactone inhibited the production of NO, PGE2 and TNF-α by suppressing iNOS and COX-2 expression. ► Alantolactone modulated inflammatory responses by blocking NF-κB, MAPK and AP-1 activation. ► These effects were mediated via inhibition of the MyD88 signaling pathway.