Apoptosis-enhancing effect of Honokiol on Temozolomide plus <i>O</i>^<i>6</i>-BG-treated GBM8401 SP cells.

<p>GBM8401 SP cells were treated with 0.05% DMSO (A), 5 μM Honokiol (B), 10 μM TMZ (C), 5 μM Honokiol combined with 10 μM TMZ (D), 10 μM TMZ plus 10 μM <i>O</i>^<i>6</i>-BG (E), and 5 μM Honokiol combined with 10 μM TMZ plus 10 μM <i>O</i>^<i>6</i>-BG (F) for 72 h, respectively. After harvest, cells were fixed and stained with PI for 30 min and the cell cycle was examined by flow cytometry. Honokiol enhanced <i>O</i>^<i>6</i>-BG combined with TMZ-mediated cytotoxicity through promoting the apoptotic cell death. H, Honokiol; T, TMZ; B, <i>O</i>^<i>6</i>-BG.