SC-560

SC-560 is a potent and selective COX-1 inhibitor with an IC₅₀ of 9 nM. IC50 & Target: IC50: 9 nM (COX-1), 6.3 μM (COX-2)^[1] In Vitro: Preincubation of COX-1 with SC-560 inhibits the conversion of arachidonic acid to PGE2 in a concentration-dependent manner. The IC₅₀ of SC-560 for COX-2 is 6.3 μM, nearly 1,000-fold higher than with COX-1^[1]. SC-560 shows a dose and time dependent inhibitory effect on HCC cell growth. SC-560 also inhibits colony formation in soft agar and induces apoptosis in HCC cells in a dose-dependent manner. Moreover, SC-560 decreases the levels of the anti-apoptotic proteins survivin and XIAP and activates caspase 3 and 7 in a dose and time dependent fashion^[2]. In Vivo: Oral dosing with either 10 or 30 mg/kg SC-560 1 hour before assay completely inhibits ionophore-stimulated TxB2production, indicating that SC-560 is orally bioavailable and inhibits COX-1 in vivo^[1]. SC-560 extensively distributes into rat tissues, and has a CL approaching hepatic plasma flow. The drug displays low less than 15% and formulation dependent bioavailability after oral administration and demonstrates kidney toxicity^[3].