Cell viability assay
5 x 103 cells were seeded in 96-well plates and treated with different concentrations (0, 0.5, 1, and 5 μM) of empagliflozin with or without IL-1β (10 ng/ml) for 24 h. The equal volume of vehicle was used in the control group. To analyze cytotoxicity of empagliflozin on chondrocytes, CCK-8 assays (MCE, HY-K0301) were conducted according to the manufacturer’s instruction. The optical density (OD) value was read at a wavelength of 450 nm.