Differential control of growth, apoptotic activity and gene expression in human colon cancer cells by extracts derived from medicinal herbs, Rhazya stricta and Zingiber officinale and their combination

Figure 3 Combination of crude alkaloid and flavonoid induce biochemical features of apoptosis. HCT116 cells were treated for 24 h with indicated concentrations of crude alkaloid extract of R. stricta (CAERS) and/or crude flavonoid extract of Z. officinale (CFEZO) and assayed for existence of apoptotic cell death. A: Fluorescent images from Hoechst 33342 staining (first and second rows) or acridine orange/ethidium bromide (third row) (arrows indicate nuclear condensation, DNA fragmentation, and perinuclear apoptotic bodies) (magnification: first row: × 20; second and third rows: × 40); B: Agarose gel showing DNA fragmentation in HCT116 cells; C: Comet assay showing formation of DNA tail in CAERS and CFEZO-treated HCT116 cells. Nuclei with damaged DNA have the appearance of a Comet with a bright head and a tail, whereas nuclei with undamaged DNA appear round with no tail.