YS121

YS121 is a dual inhibitor of mPGES-1 (IC₅₀ = 3.9 μM) and 5-LO (IC₅₀ = 4.1 μM). It effectively inhibits PGE2 and LT synthesis in both cell free and intact cell assays. Moreover, YS121 (1.5 mg/kg, intraperitoneal) reduced pleural levels of PGE2 and LTB4 while blocking exudate formation and leukocyte infiltration in carrageenan-induced rat pleurisy. YS121 has minor effects on Cox-1 and Cox-2, inhibiting these enzymes 24.8% and 38%, respectively, at 10 μM.