Cell Viability Assay

3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay was used to determine the effect of the treatment on cell viability. MDA-MB-231 cell lines were cultured in 96-well plates. When the cells became adherent after 24 hours, the cell culture medium in the experimental group was replaced with 100 μL medium containing different concentrations of ginsenoside 20(S)-Rg3 (0, 10, 80, 150 µmol/L) and curcumin (0, 10, 30, 50, 90 µg/mL). Cells in the control group were only treated with the same medium. One hour after the treatment, the cells were radiated and then incubated at 37 °C. After 24, 48, and 72 hours of exposure to ginsenoside 20(S)-Rg3, curcumin, and radiation. The MTT solution (0.5 mg/ml final concentration) was added and incubated for an additional four hours at 37 °C. The liquid was removed, and 100 μL of the MTT solvent was added, and then it was shaken for 10 min. Finally, spectrophotometric absorbance was measured at 570 nm using ELISA reader, and the optical density (OD) for each well was determined.