Fig. 4

Effect of DK226 on collagen-induced arthritis (CIA) in rat knee joints. a Effect of intra-articular hyaluronic acid (HA) (0.5 mg) or DK226 (0.5 mg HA-equiv, 26 nmol MTX-equiv) on knee swelling of the right knee (treated) shown on the left panel, and the effect in the left knee (untreated) shown on the right panel. b Histopathology of the right knee joints after treatment with intra-articular HA or DK226. Sections were stained with safranin O/fast green. T tibia, Mmeniscus, F femur. Scale bars indicate 100 μm. c and d Histologic analysis of synovial tissue (c) and lateral condyle of the femur (d). Values are means and standard error of the mean (SEM) (n = 3–10 in a, c and d: n = 3, Normal + vehicle; n = 9–10, CIA + vehicle, HA or DKA226). ^# P < 0.05: significantly different from Normal + vehicle group (Wilcoxon rank sum test). *P < 0.05: significantly different from HA group (Wilcoxon rank sum test)