Cell Viability Assay

Cell viability was evaluated using a Cell Counting Kit-8 (CCK-8) assay kit (Dojindo Laboratories Tokyo, Japan). Briefly, the cells were seeded into 96-well tissue culture plates at a density of 1 × 10⁴ cells/well and treated with the indicated concentrations of AT-I. After 24 or 48 h of incubation, 10 μL of CCK-8 solution was added and then the cells were incubated for a further 1 h. The absorbance of cells at 450 nm was measured using a microplate reader (Bio-Rad Laboratories, Richmond, CA, USA).