RESUMO
OBJECTIVE: To explore the mechanism of action of Juanbi Capsules, a Chinese medicine for invigorating the kidney and replenishing qi, in preventing osteoarthritis of the knee in rabbits. METHODS: Seventy-two 4-month-old, Japanese long-eared white rabbits were randomly divided into 6 groups: control (group A), model (group B), Chinese drug; high-dose (group C), Chinese drug; mid-dose (group D), Chinese drug; low-dose (group E), and drug control (group F). With the exception of the rabbits in group A, each rabbit was subjected to plaster cast fixation for 6 weeks to induce osteoarthritis. In addition, rabbits were administrated with an intragastric injection of the Chinese drug (groups C, D and E) or an aminoglucose hydrochloride capsule (group F) for 4 weeks. Blood was drawn from the central ear artery for serum MMP-2 and MMP-9 concentrations, and the knee joint cartilage was harvested for gross observation and light microscopy. RESULTS: There were significant differences in serum MMP-2 and MMP-9 concentrations between group B and groups C, D and E (P < 0.05), with no significant differences between groups D and F. Histological results showed various changes in tissue staining with treatment, with osteophyte and bone cyst formation, and superficial erosion in the articular surface of the cartilage; in some cases, the defect reached the mid-layer of the cartilage, and these changes were lower than those in the model group. CONCLUSION: Juanbi Capsules assist in preventing osteoarthritis in the rabbit, possibly by decreasing serum MMP-2 and MMP-9 levels.
