Splitomicin (Splitomycin) is a selective Sir2p inhibitor. Splitomicin inhibits NAD+-dependent HDAC activity of Sir2 protein. Splitomicin induces dose-dependent inhibition of HDAC in the yeast extract with an IC50 of 60 μM.In Vitro: Splitomicin (10-333 μM; 24 hours) elicits antiproliferative effects in MCF-7 and H1299 cells in a dose-dependent manner in colony formation assay. Splitomicin (33 μM) fails to decrease the number of colonies, but Splitomicin (100 and 333 μM) effectively inhibits colony formation in MCF-7 and H1299 cells[2].In Vivo: Splitomicin (80 mg/kg with an intraperitoneal injection every 24 h for 5 days, in mice) enhances tissue factor (TF) activity in the arterial vessel wall and accelerates carotid artery thrombus formation in a photochemical injury model.