Downregulation of matrix metalloproteinase-13 by the root extract of Cyathula officinalis Kuan and its constituents in IL-1β-treated chondrocytes.

The roots of Cyathula officinalis Kuan are widely used in Chinese medicine for the treatment of inflammatory disorders. Here, the ability of C. officinalis Kuan to downregulate matrix metalloproteinase (MMP)-13 was examined since MMP-13 is an important enzyme for the degradation of the cartilage collagen matrix, especially under arthritic conditions. The ethanol extract of C. officinalis Kuan as well as the N-hexane and chloroform soluble fractions were found to potently inhibit MMP-13 induction in IL-1 β-treated SW1353 cells, a human chondrosarcoma cell line, at 50-200 µg/mL. Activity-guided separation led to the isolation of six compounds, palmitic acid (1), β-sitosterol (2), α-spinasterol (3), atractylenolide I (4), 1,3-diacetoxy-tetradeca-6E,12E-dien-8,10-dyn (5), and N-trans-feruloyl-3-methyldopamine (6). Among these, 4 and 5 exhibited MMP-13 downregulating activity in IL-1 β-treated SW1353 cells. And 4 also showed anti-oedematous activity against λ-carageenan-induced paw edema in mice at 20-200 mg/kg, p. o. The results of this study provide information that can help elucidate the action mechanism of C. officinalis Kuan. In addition, the results presented here suggest that C. officinalis Kuan and its constituents may have the potential for chondroprotection against cartilage degrading disorders.