Fig. 2.

Protective effects of DAS on chondrocytes induced by H₂O₂. A The chemical structures of DAS. B Effects of DAS on chondrocyte activity. After being cultured with DAS (0.5, 1, 2.5, 5, 10, 15 and 20 μM) for 24 h, cell proliferation was determined by CCK8 assay. C Effects of DAS on chondrocyte activity. After being cultured with DAS (2.5 and 5 μM) for different treatment times (12, 24, 48 and 72 h), cell proliferation was determined by CCK8 assay. D Chondrocytes were pretreated with DAS (0.5, 1, 2.5, and 5 μM) for 24 h in the presence and absence of H₂O₂ (200 μM), and cell activity was measured by CCK8 assay. The values are mean ± SD. #p < 0.05 versus control group, *p < 0.05, **p < 0.01, and ***p < 0.001 versus control group. E Morphological analysis of chondrocytes after different treatments (magnification ×100, scale bar = 100 μm). F Chondrocyte phenotype, glycosaminoglycan production and matrix degradation were evaluated by Safranin O staining (magnification ×100, scale bar = 100 μm). G Statistical analysis of Safranin O staining