Effect of Ecd and IL-1 beta on chondrocytes. A Ecd treatment enhance chondrocytes viability. Chondrocytes at every concentration proliferate actively, with significant statistical differences observed between chondrocytes treated with Ecd and that of the control. Chondrocytes’ viability reaches its maximal beneficial effect at 10−8M Ecd after 10 days of culture. B and C IL-1β induce HIF-2α (encoded by Epas1) gene expression in chondrocytes. In this study, mouse articular chondrocytes are treated with IL-1β cytokines. The results showed that IL-1β can enhance Epas1 gene expression, while suppress collagen type II (Col2a1) gene expression. (Each value is the mean ± standard deviations; n = 8; *:p<0.05; **:p< 0.01; ***:p < 0.001).