Differentiation-inducing effects of verticinone, an isosteroidal alkaloid isolated from the bulbus of Fritillaria ussuriensis, on human promyelocytic leukemia HL-60 cells.

The inducer of differentiation of human promyelocytic leukemia HL-60 cells is commonly accepted to have potential therapeutic importance. Verticinone, one of the major isosteroidal alkaloids from the bulbus of Fritillaria ussuriensis, was found to inhibit the growth of HL-60 cells by inducing these cells to differentiate toward granulocytes. Importantly, the combination of verticinone with all-trans retinoic acid (ATRA), a well-known inducer of HL-60 cells into granulocytic lineages, was more effective than either alone, suggesting its therapeutic use in minimizing the effective dose of ATRA.