(S)-p38MAPKinhibitor III is a methylsulfanylimidazole that inhibits p38 MAP kinase (IC50 = 0.90 μM in vitro). It is cell-permeable, potently blocking the release of TNF-α and IL-1β from human peripheral blood mononuclear cells (IC50s = 0.37 and 0.044 μM, respectively).
p38MAPKinhibitor IV is an ATP-competitive inhibitor of p38 MAP kinases with IC50 values of 0.13, 0.55, 5.47, and 8.63 μM for p38α, p38β, p38x, and p38δ, respectively, in vitro.[1] It also inhibits LPS-induced TNF-α and IL-1β cytokine production (IC50s = 22 and 44 nM, respectively) in human peripheral blood mononuclear cells.