Conseil national de recherches du Canada. Science des mesures et étalons
Extracts from the tubers of Stephania venosa (Blum) Spreng growing in Vietnam significantly inhibited cell proliferation against a number of cancer cells including HeLa, MDA-MB231 and MCF-7 cells. A bioassay-guided fractionation led to the isolation of four aporphine and one tetrahydroprotoberberine alkaloids: dehydrocrebanine 1, tetrahydropalmatine 2, stephanine 3, crebanine 4 and O-methylbulbocapnine 5. The characterization of these compounds was based on MS, NMR and published data. A study by structure–bioactivity relationship on these isolates showed that stephanine is the most active compound. Cell biological studies showed that stephanine induces the reverse of mitotic exit, eventually leading to cell death by apoptosis. This data suggests that stephanine has a unique mode of cell-killing activity against cancer cells, which is seldom observed with known synthetic compounds. In addition to its anticancer property, our data from an in vitro study showed that S. venosa also possesses effective antiplasmodial activity and stephanine was also the most interesting compound but is the most cytotoxic with the lowest selectivity index.