Fig. 4

Effect of EE extract on phosphatidylserine exposeure for B16 cells. Cells were exposed to 15 μg/ml EE extract for 0, 4, 8, 16, and 24 h. (a) Representative dot plots of Annexin V/PI staining detected by flow cytometry are shown. The upper left (UL) quadrant contains the necrotic (Annexin V−/ PI+) population. The upper right (UR) quadrant contains the late apoptotic/necrotic (Annexin V+/PI+) population. The lower left (LL) quadrant contains the vital (double negative) population. The lower right (LR) quadrant contains the early apoptotic (Annexin V+/PI-) population. The result is from one experiment representative of three similar experiments. (b) The percentage of necrotic cells, early apoptotic cells, viable cells and late apoptotic cells at 0, 4, 8, 16, and 24 h are indicated. Results are mean values ± SD of three independent experiments (n = 3). *p < 0.05 shows significant difference compared with control (0 h)