Boswellic acid acetate induces differentiation and apoptosis in leukemia cell lines

Boswellic acid acetate (BC-4), a compound isolated from the herb Boswellia carterii Birdw., can induce differentiation and apoptosis of leukemia cells . Based on cell morphology and NET reduction, BC-4 induced monocytic differ entiation of myeloid leukemia HL-60, U937 and ML-I cells at a dose under 12 .5 mu g/ml (24.2 mu M). BC-4 was a potent inducer, with 90% of the cells sh owing morphologic changes and 80-90% of the cells showing NET reduction. Sp ecific and non-specific esterase were also increased by BC-4. Based on benz idine staining assay, BC-4 failed to induce erythroid leukemia DS-19 and K5 62 cells differentiation. In contrast to its selective differentiation effe ct, BC-4 strongly inhibited growth of all cell lines tested. The growth inh ibition effect was dose- and time-dependent. In HL-60 cells, 20 mu g/ml (38 .8 mu M) of BC-4 decreased viable cell number by 60% at 24 h, whereas at 3 days there was virtually no viable cells. Morphologic and DNA fragmentation analysis proved that BC-4 induced cell apoptosis. The dual apoptotic and d ifferentiation effects of BC-4 suggest that it may be a powerful agent in t he treatment of leukemia. (C) 1998 Elsevier Science Ltd. All rights reserve d.