2.3 Cell viability
Cell viability was determined using the CCK-8 assay. HK-2 cells were inoculated into 96-well culture plates (1×104/well) and treated with leonurine and cisplatin for 24 h. Thereafter, 10 μL of CCK-8 reagent was added to each well, and the plate was cultured at 37 ℃ for 1 h. The OD value at 450 nm was then measured with an enzyme-labeling instrument to determine the cell survival rate.