Effects of casticin on TRAIL-induced apoptosis in gastric cancer cells.

<p>Casticin enhanced TRAIL-induced apoptotic cell death measured using flow cytometric analysis (A and B), cell apoptosis ELISA detection kit (C and D) in BGC-823, SGC-7901, and MGC-803 cells (mean±SD, n=3). <sup>*</sup><i>P<0.05</i> vs. treatment with DMSO or 0 h; <sup>#</sup><i>P<0.05</i> vs. treatment with 1 µmol/l casticin or TRAIL at the same concentration alone for 6 h. The enzymatic activities of caspase-3(E), -8(F), and -9(G) were determined by incubation of 20 µg of total protein with 200 µM chromogenic substrate (Ac-DEVD-<i>p</i>NA or Ac-IETD-<i>p</i>NA or Ac-LEHD-<i>p</i>NA) in 100 µl assay buffer for 2 h at 37 °C. The release of chromophore <i>p</i>-nitroanilide (<i>p</i>NA) was monitored by a spectrophotometer (405 nm). Data shown are the mean±S.D (n = 3). * <i>p</i><0.01 vs. 0.1% DMSO; # <i>p</i><0.05 vs. treatment with casticin and TRAIL alone. The cleavage of PARP was examined by western blotting analysis in BGC-823 and SGC-7901 cells (H).</p>