Induction of Arthritis

The 5% carrageenan/kaolin-induced arthritic rat model was prepared as described previously [10]. Animals were briefly anesthetized with 3% isoflurane in a N₂O/O₂ mixture. Arthritic inflammation was induced by a single injection of 3% carrageenan/kaolin suspended in 100 μL of pyrogen-free sterile saline, into left knee joints. To evaluate the arthritic progression of carrageenan/kaolin-induced arthritis rat, three different parameters were measured: knee thickness, weight distribution ratio (WDR), and using knee flexion test squeaking scores. These were considered behavioral indicators of carrageenan/kaolin-induced arthritis through checking for 6 days. As arthritis progression, redness and swelling of knee joints and arthritic pain started to appear and reached a maximum on day 1 after the carrageenan/kaolin injection. Daily JC3 injections 5 or 10 mg/kg were started 24 h after the carrageenan/kaolin injection and continued for 5 days. All behavioral tests were performed blinded.