The present study focused on the effect of a series of extracts and two 5,6,7-trioxygenated coumarins isolated from Pterocaulon polystachyum on the proliferation and differentiation of human promonocytic U-937 cells. The petroleum ether extract was the only extract that significantly reduced cell proliferation and induced cell differentiation. Treatment with pure 5-methoxy-6,7-methylenedioxycoumarin (C1) and 5-(3-methyl-2-butenyloxy)-6,7-methylenedioxycoumarin (C2), present in the petroleum ether extract, showed a time and concentration-dependent inhibition on cell proliferation. In addition, the coumarin derivatives were also able to induce CD88 functionality and NBT reduction, markers of monocytic cell differentiation. These results suggest that C1 and C2 might have a potential therapeutic role in the management of leukemia.
Copyright 2004 Elsevier Ireland Ltd.