Figure 4. A, Effect of naringenin (NG) on gene expression of MMP-1, MMP-3, MMP-13, ADAMTS-4, and ADAMTS-5 in rat chondrocytes. The rat articular chondrocytes were cultured for 2 days and were incubated with 20 and 40 μM of NG for 3 h. Subsequently, the cells were incubated in IL-1β (20 ng/mL) for 24 h with a negative control of absence of IL-1β. B, Effect of NG on proliferation of rat chondrocytes. Seeding of chondrocytes was performed (2×105 cells/mL) for 24 h under varying concentrations of naringenin ranging from 10 to 100 μM. The proliferation of cells was estimated by sulforhodamine-B (SRB) assay. Data are reported as means±SEM. *P≤0.05, compared to IL-1 β; #P≤0.05 and # #P≤0.01, compared to IL-1β (ANOVA with Bonferonni’s post hoc multiple corrections).
