Figure 1.

PCA relieves ACLT-induced osteoarthritis. Rats with surgically induced ACLT were treated with or without PCA for 0, 1, 2 and 4 weeks. Levels of (A) CTX–II and (B) CTX–I in the knee joints were tested by ELISA. (C) The degenerative changes in the articular cartilage were examined by Safranin-O/Fast Green staining. Rats undergoing sham surgery were used as a control. The results are shown as the percentage mean ± SEM (n=6). Statistical analysis: ANOVA with Tukey's post-hoc test; NS, **P<0.01 vs. sham; ^##P<0.01 vs. ACTL. Scale bars, 500 µm. ACLT, anterior cruciate ligament transection; CTX, C-terminal telopeptide of type I collagen; PCA, protocatechuic acid.