Cytotoxicity of Crude Extract and Isolated Constituents of the Dichrostachys cinerea Bark towards Multifactorial Drug-Resistant Cancer Cells

Figure 3

Evaluation of apoptosis induced by the crude extract, betulinic acid (1), and doxorubicin on CCRF-CEM leukemia cells after 24 h as determined by annexin V/PI assay. Apoptosis was assessed by flow cytometry after annexin V-PI double staining. IC₅₀ values were 5.69 μg/mL for the crude extract, 8.80 μM for 1, and 0.02 μM for doxorubicin. Necrotic cells lose membrane integrity, allowing PI entry. Q9-LL: viable cells exhibit annexin V (-)/PI (-); Q9-LR: early apoptotic cells exhibit annexin (+)/PI (-); and Q9-UR and Q9-UL: late apoptotic cells or necrotic cells exhibit annexin V (+)/PI (+) or annexin V (-)/PI (+).