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 1 Combination of crude alkaloid and flavonoids acts synergistically to inhibit cell proliferation and colony formation in HCT116 cells. A: Cell viability of HCT116 cells (5 × 10⁴ cells/well) treated with the indicated concentrations of crude alkaloid extract of R. stricta (CAERS) and/or crude flavonoid extract of Z. officinale (CFEZO) for 24 h (white bars), 48 h (gray bars) and 72 h (light grey bars) were assess by trypan blue dye exclusion assay. The experiments were repeated five times in triplicates, and values are reported as the mean ± SD; B: For colony formation, HCT116 cells treated with the indicated concentrations of CAERS and/or CFEZO and counted under a dissection microscope and the experiment was repeated three times (magnification: × 6); C: Crystal violet staining of HCT116 cells grown in soft agarose assays to assess anchorage-independent growth. HCT116 cells were treated with CAERS (25 μg/mL), CFEZO (25 μg/mL), or a combination (3 μg/mL) for 2 wk (magnification: × 6).