2.5. Cell viability assay

Cellular viability was detected by the Cell Counting Kit-8 (Beyotime Biotechnology, Shanghai, China). Cells were cultured in 96-well plates at 100 μl volume per well. After drugs treatment, 10 μl CCK8 solution was added in the medium directly and incubated for 2 h at 37 °C. The absorbance of each well was determined at 450 nm by a Microplate Reader (Bio-Rad, Hercules, CA, USA).