Bufalin as a New Potent Inducer of Differentiation of Human Leukemia Cells-A Story of the Search for Active Substances from Oriental Medicines-

Chan'su the dried toad venom preparation, has been used for centuries as a cardiotonic a local anesthetic and in the treatment of ecphyma. Bufadienol ides are major effective components of Chan'so. Their pharmacological activities have been studies to date. However, their pharmacokinetic and metabolism have not been studied. Considering variously divergent pharmacological actions of bufadienolides we decided to examine their metabolism and their other biological activites. We isolated and purified various components of bufadienolides. Cinobufagin and bufalin are prominent components. Firstly we examined metabolism of cinobufagin and found that this compound was extensively metabolized into various metabolites by mixed-function oxidase and deacetylase.