Effect of coumarins on HL-60 cell differentiation

Twenty-eight coumarins, including 7 furocoumarins, were examined for their activity of induction of terminal differentiation of human promyelocytic le ukemia cells (HL-60) by nitro blue tetrazolium (NBT) reducing, nonspecific esterase, specific esterase and phagocytic activities. Esculetin, nordalber gin, 6,7-dihydroxy-4- methylcoumarin and imperatorin had strong activity am ong the coumarins examined. HL-60 cells treated with these coumarins differ entiated into mature monocyte/macrophage. The structure-activity relationsh ip established from the results revealed that 6,7-dihydroxy moiety had an i mportant role in the induction of differentiation of HL-60.