Fig. 1

Effects of daphnoretin on chondrocyte toxicity in vitro. ATDC5 chondrocytes were treated with daphnoretin at different doses (0.5, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 µM) for 48 h. A Molecular structure of daphnoretin. B MTT assay was performed to check cell viability and determine the IC50 value of daphnoretin to be 72.97 µM. ATDC5 cells were treated with IL-1β (10 ng/mL) to induce the OA cell model, followed by treatment with daphnoretin (1, 2, 4 µM). C Cell viability was assessed by the MTT assay. D Flow cytometry was implemented to determine cell apoptosis. E Expression of Bax, Caspase-3 and Bcl2 was compared by WB. F The caspase-3 cell activity assay kit was adopted to examine the influence of daphnoretin on the apoptosis of mouse chondrocytes. *P < 0.05, **P < 0.01, ***P < 0.001 (vs. con group). &P < 0.05, &&P < 0.01, &&&P < 0.001 (vs. IL-1β group). N = 3