Embelin from the Japanese Ardisia herb is a small-molecular inhibitor that binds to the XIAP BIR3 domain with which Smac and caspsase-9 bind. Embelin inhibits cell growth of both PC-3 and LNCap cells in a dose-dependent manner, with IC50 values of 3.7 and 5.7 μM. While, the toxicity of Embelin in normal PrEC and in WI-38 cells is much lower with IC50 values of 20.1 μM and 19.3 μM. Treatment of PC-3 cells with 25 and 50 μM of embelin for 48 h, 30% and 75% of cells undergo apoptosis, representing approximately 3-and 9-fold increase as compared to untreated cells. Embelin also potently suppresses the biosynthesis of eicosanoids by selective inhibition of 5-lipoxygenase (5-LO) and Microsomal prostaglandin E2 synthase-1 (mPGES-1) with IC50 = 0.06 and 0.2 mM, respectively.