Compound 5 induces apoptosis in A549 lung cancer cells. A) Fluorescence images of A549 lung cancer cells showing fragmented nuclei after DAPI staining. Scale bar: 10 µm, B) Detection of DNA fragmentation by agarose gel electrophoresis. Cells were treated and genomic DNA was extracted and electrophoresed on 1.5% agarose gels. M: DNA molecular weight marker; C: vehicle-treated control cells; 1%: 1% DMSO-treated cells; 5%: 5% DMSO-treated cells; C.5: Compound 5-treated cells. Arrows indicate DNA fragments. Three experiments were performed with similar results.