Pterostilbene and 3′-hydroxypterostilbene induced apoptosis in COLO205 cancer cells.

<p>Cells were treated with various concentrations (5, 10, 25 and 50 µM) of pterostilbene or 3′-hydroxypterostilbene for 24 h. (A) Determination of sub-G1 cells in COLO 205 cells by flow cytometry after PI staining as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111814#s2" target="_blank">Materials and Methods</a>. (B, C) After treatment, total cell lysates were prepared from COLO 205 cells and the cleavage of PARP, DFF-45, pro-caspase 8 and pro-caspase 9 were analyzed by Western blotting. (D) Kinetics of caspase activation in COLO 205 cells. Cells were treated with 25 and 50 µM of pterostilbene or 3′-hydroxypterostilbene for 24 h. Caspase activities were analyzed as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111814#s2" target="_blank">Materials and Methods</a>. (E) Cells were treated with 50 µM of pterostilbene or 3′-hydroxypterostilbene for 15 min. Mitochondrial membrane potential and ROS production were stained with DiOC6 (40 nM) and DCFH-DA (20 µM) and measured by flow cytometry. The values are expressed as means ±SE of triplicate tests. *<i>P</i><0.05 indicates statistically significant difference from the pterostilbene-treated group.