Effects of the selective CB
agonist, JWH133 on CIA mice. JWH133 (1 mg/kg/day or 4 mg/kg/day) or vehicle (n = 12 each) was injected intraperitoneally twice daily from day 15 to day 35. The arthritis severity was recorded as the arthritis score (A) and paw thickness (B). Overtime analysis of arthritis score and paw thickness by 2-way ANOVA revealed significant difference between vehicle group and 4 mg/kg/day grope (p < 0.01). Representative hematoxylin and eosin staining of ankle joints from normal mice and from mice with CIA after the treatment with vehicle or JWH133 (4 mg/kg/day) are shown (C). Bar, 200 μm. Inflammatory cell infiltration in the ankle joints was evaluated with the histological score (D). Representative radiographs of the ankle joints of normal mice and CIA mice treated with vehicle or JWH133 (4 mg/kg/day) (E). Arrows indicate bone erosion. Bone erosion in the bilateral MTP joints was evaluated with the bone destruction score (F). Splenocytes from normal mice and CIA mice treated with vehicle or JWH133 (4 mg/kg/day) were cultured with CII for 72 h. Concentrations of IFN-γ (G) and IL-17 (H) in the cultured supernatant were measured by ELISA. N: normal, V: vehicle, J: JWH133, NS: not significant. Serum samples were obtained at day 36 from normal mice and CIA mice treated with vehicle or JWH133 (4 mg/kg/day), and anti-CII IgG1 antibody level was measured by ELISA (I). Values are the mean ± SEM. *p < 0.05 versus vehicle.