Background: The formation of new blood vessels (angiogenesis) is a critical component in a variety of pathological settings, including solid tumor growth, macular degeneration, and atherosclerosis.
Methods and results: We have found that orally administered spironolactone inhibited the area of angiogenesis induced by basic fibroblast growth factor (bFGF) in a rabbit corneal micropocket assay. Additionally, spironolactone inhibited bFGF- and vascular endothelial growth factor-stimulated capillary endothelial cell proliferation in vitro, inhibited bFGF-stimulated capillary endothelial cell chemotaxis in vitro, and caused avascular zones when placed on the chick chorioallantoic membrane. Experiments analyzing spironolactone metabolites revealed that the major human metabolites 6 beta-hydroxy-7 alpha-thiomethyl spironolactone and canrenoic acid retained antiangiogenic activity. The antiangiogenic activity appears to be unrelated to the antiandrogenic and antimineralocorticoid effects of spironolactone.
Conclusions: These experiments hold promise for the potential use of spironolactone as an orally administered drug for the treatment of many diverse diseases dependent on angiogenesis.