Effects of magnolol on DNA fragmentation and activation of apoptotic proteins in A431 cells. (A) DNA fragmentation. Cells were treated with magnolol (0-150 μM) for 48 hours, at the end of the treatment, adherent and non-adherent cells were collected and subjected to TUNEL assay. The gate M1 includes the apoptotic cells with fragmented DNA, which were positive for green fluorescence. The bar graph indicates the percentages of apoptotic cells with fragmented DNA. In each case, data represents mean ± SE of three observations. *p < 0.05 indicates statistical significant difference in magnolol treated groups compared with the control. (B) Effects of magnolol on the activation of apoptotic proteins in A431 cells. Cells were treated with magnolol for 24 and 48 h, cells were then collected. Cell lysates were prepared and subjected to SDS-PAGE and Western blot analysis. Membranes were probed with appropriate antibodies. Pictures are representative from three experiments.