Digitoxin

A cardiac glycoside; inhibits human recombinant α1β1, α2β2, and α3β1 subunit-containing Na+/K+-ATPases (Kis = 250, 63, and 136 nM, respectively); also inhibits hERG in HEK293 cells expressing hERG (IC50 = 11.1 nM); enhances developed tension and contractile force in electrically stimulated isolated guinea pig left atrial muscle at 0.2 and 0.4 µM, respectively; metabolized to digoxin in isolated rat liver microsomes; attenuates congestive heart failure and reduces myocardial hypertrophy in a rat model of myocardial infarction induced by coronary artery ligation at ~1 mg/kg per day); cytotoxic to a panel of 10 human cancer cell lines (IC50s = 12-76 nM)