Effect of RIAA in mice model of CIA. The DBA/1J mice were injected intradermally with 100 μg of bovine type II collagen. After 21 days the mice were given a booster dose. CIA was fully developed at day 28 when treatments initiated and continued for the next 14 days. The arthritis index was assessed every other day. (A) The mean arthritis index for 3 RIAA treatment groups (10, 50 and 250 mg/kg body weight), celecoxib-treated group (20 mg/kg body weight) and the vehicle-treated control group. Day 42 data are expressed as mean ± SEM. Mice in the non-diseased group had an arthritis index of 0 throughout the experiment and therefore the data points were not displayed. (B) After evaluation of the arthritis index was completed at day 42, mice were anesthetized, and a histological examination was performed in 3 RIAA treatment groups, celecoxib-treated group and the vehicle-treated group (mean ± SEM). *a significant difference (P < 0.05) in histology score compared to diseased control after Dunnett post-hoc adjustment.