Figure 4.

Whole plant extracts induce cell death of tumor cells via apoptosis. (a)-(b) Caspase 3 activity (a) and cell death (b) of Colo205 tumor cells exposed to plant extracts 5, 10, and 11 for 24 or 48 h. Caspase 3 activity was determined as described in Materials and Methods. The columns depict changes in caspase 3 activity as the fold increase for each plant extract at both time periods. (c) Colo205 cells were treated with extract 5 (1.5 mg/mL), for 2 or 4 h, and cell lysates were prepared. After treatment, total protein extracts from the cells were separated by SDS-PAGE and analyzed by western blot analysis using anti-human PARP antibodies. Arrows indicate the full-length PARP protein (116 KDa; upper arrow), and its cleaved product (89 KDa; lower arrow), following exposure of the cells to plant extract 5. (d) DNA fragmentation in Colo205 cells exposed to plant extract 5. For detection of DNA fragmentation, DNA was extracted from Colo205 cells exposed to Etoposide (50 μL/mL; for 48 h) or extract 5 (1.5 mg/mL) for various time periods. From left to right: DNA extracted from control Colo205 cells, not exposed to any inducer (48 h; line 1); DNA extracted from cells exposed to extract 5 for 24 h (line 3), 48 h (line 5), 72 h (line 7), or Etoposide (line 9).