Fig. 2.

In vitro arctiin treatment regulates cartilage extracellular matrix (ECM) homeostasis. A The cell viability of arctiin-treated chondrocytes at 2.5, 5, or 10 μM concentration following stimulation with 10 ng/mL IL-1β (n = 6). B The transcript levels of anabolic genes, including Col2a1 and Acan, were quantified with real-time RT-PCR using GAPDH as the internal reference (n = 4). C The transcript levels of the catabolic genes Mmp13 and Adamts5 were quantified with real-time RT-PCR (n = 4). D, E Immunofluorescence staining indicated the expression of ECM synthesis markers: COLII and ACAN, and the ECM degrading enzymes: MMP13 and ADAMTS5 (n = 3). F The protein levels of COLII, ACAN, MMP13, and ADAMTS5 were determined using Western blot assays (n = 3). Values represent mean ± SD. Statistically, significant differences are indicated by ^# where p < 0.05, ^## where p < 0.01 compared with the IL-1β group or * where p < 0.05, ** where p < 0.01 between the indicated groups