Research Article

Cytotoxic Constituents of the Bark of Hypericum roeperianum towards Multidrug-Resistant Cancer Cells

Figure 3

Apoptosis induced by the crude extract (HRB), trichadonic acid, and doxorubicin after 24 h on CCRF-CEM leukemia cells as determined by annexin V/PI assay. Apoptosis was assessed by flow cytometry after annexin V-PI double staining. IC50 values were 13.71 µg/mL for HRB, 14.44 µM for trichadonic acid, and 0.02 µM for doxorubicin. Mean values ± SD of three independent experiments is shown. Data with different superscript letters are significantly different ().