2.3. Cell viability assay

Cytotoxic effects of the flavanones were investigated by MTT assay. In short, the cells in 96‐well plates were incubated for 24 hr before treated with different concentrations of each flavanone (10, 20, 40, 80, and 100 µM) for 24 hr in 10 replicates. Subsequently, the medium was removed prior to addition of MTT into each well. After 3 hr of incubation at room temperature, the formanzan compound was dissolved by DMSO for 30 min. Finally, the absorbance was measured at 570 nm using VersaMax microplate reader (Molecular Devices LLC). The experiment was repeated three times.