Figure 9

Caspase 3/7 activation by Siamois polyphenols and withaferin A in K562 and K562/Adr cells. A) K562 and K562/Adr cells were either left untreated or treated with 100 μM of quercetin (Q), kaempferol (K), eriodictyol (E), WP283 (WP) or 6 μM of withaferin A (WA) for 12 h. Caspase-3 activity present in cell lysates was determined by a fluorescent in vitro assay upon incubation of cell lysate with Ac-DEVD-fmk substrate. B) K562 and K562/Adr cells were either left untreated or treated with 100 μM quercetin for 6, 12, 24, 36 or 48 h. Caspase-3 activity present in cell lysates was determined by a fluorescent in vitro assay upon incubation of cell lysate with Ac-DEVD-fmk substrate. C) Percentage of living cells, following treatment with withaferin A (10 μM) or quercetin (100 μM) in the presence or absence of ZVAD fmk (50 μM), inhibitor of caspases. In all conditions, except control, cells were cultivated in medium containing 1% DMSO. After 48 h of cultivation, % dead cells were stained by annexin V/propidiumiodide followed by flow cytometry measurement. % Living cells is obtained by subtracting % dead cells. Data of two independent experiments, each done in duplicate, are presented as mean ± S.E.M.