Figure 2.

The concentration-dependent effects of CH2Cl2 and MeOH extracts (0-200 μg/ml) and 7-hydroxy-8-(4-hydroxy-3-methylbutoxy) comarin (armenin), 8-hydroxy-7-(4-hydroxy-3-methylbutoxy) comarin (isoarmenin) and deoxylacarol on the viability of K562 and HL-60 cells. Among three compounds armenin exhibited high cytotoxic activity against apoptosis-proficient HL-60 and apoptosis-resistant K562 cells, with IC50 values ranging from 22.5 to 71.1 μM with much less cytotoxic effects on normal human lymphocytes. Paclitaxel 1 μM was used as positive control. Values were mean±SD of at least three independent experiments, each in triplicates. +P < 0.05, ++P < 0.01 and +++P < 0.001 compared to control.