Induction of apoptosis and loss of mitochondrial membrane potential (MMP) in STE- treated cultured cells.

<p>(A) Induction of apoptosis in STE-treated mammalian cells was determined by annexin V-FITC and PI double staining. Apoptotic cells were analyzed flow cytometrically, and a dot plot representation of annexin-V-FITC-fluorescence (<i>x</i>-axis) vs PI-fluorescence (<i>y-</i>axis) has been displayed. Mitochondrial membrane potential in STE-treated HepG2 cells (B) and A549 cells (C) were monitored flow cytometrically by using the fluorescent probe Rhodamine 123. MMP was determined using a FACS Calibur flow cytometer (BD) with excitation at 488 and emission at 535 nm. Results are expressed as a histogram analysis, average of three experiments with SEM [P<0.05 vs control (STE-untreated cell), n = 3].