Figure 4. Gambogic acid induces apoptosis of cancer cells.
A, Gambogic acid was used to treat HL-60 (black symbols) or Jurkat (white symbols) cells at concentrations of 0, 0.1, 0.2, 0.5, 2, 5 μM (from left to right). Cells were collected after 20 hrs, stained with FITC-Annexin V and PI, and the percentage of Annexin V-positive/PI-negative cells was determined. B, PPC1 cells were treated with gambogic acid at concentrations of 0, 0.5, 1, 2, 5, 10 μM. After 20 hrs, the cells were collected and the cell lysates were analyzed by SDS-PAGE/immunoblotting using anti-caspase 3 antibody. The positions of uncleaved proform and cleaved large subunit of the enzyme are indicated.