Fig. 7

The inhibitory effects of pimaric and kaurenoic acids in the pro-inflammatory cytokine-induced catabolic expression in primary culture articular chondrocytes. Primary cultured articular chondrocytes were exposed to pimaric acid (0–50 µg/mL) in the absence or presence of (a) IL-1β (1 ng/mL), (b) TNF-α (10 ng/mL) and (c) LPS (10 ng/mL) for 24 h. Thereafter, mRNA expression of anabolic or catabolic factors was analyzed. Chondrocytes were exposed to kaurenoic acid (0–50 µg/mL) in the absence or presence of (g) IL-1β (1 ng/mL), (h) TNF-α (10 ng/mL), and (i) LPS (10 ng/mL) for 24 h. Thereafter, mRNA expression of anabolic or catabolic factors was analyzed. In addition, semi-quantification results are presented in (d, e, f, j, k, and l). The results are representative of at least six independent experiments. Values are presented as mean ± standard error of the mean (SEM) (*P < 0.05, **P < 0.01, and ***P < 0.001 vs. IL-1β, TNF-α, or LPS only), as analyzed via one-way ANOVA