Immunopharmacology and InflammationAnti-inflammatory effect of quetiapine on collagen-induced arthritis of mouse

Quetiapine is an atypical antipsychotic and has also been used in the treatment of depression. Since anti-inflammatory effects of antidepressants are well established, we hypothesized that quetiapine may also exert anti-inflammatory effects. Thus this study was designed to examine the anti-inflammatory effect of quetiapine in murine collagen-induced arthritis. Mice were immunized with collagen type II for the induction of arthritis and treated with quetiapine (10 mg/kg) daily for 2 weeks. Mice were divided into 3 groups: control, CIA, and CIA + quetiapine treatment. Arthritic index and paw thickness were used to compare severity of arthritis. In additions, radiological and histological assessments were employed. Anti-type II collagen-specific antibody, interleukin-6 (IL-6), interleukin-17 (IL-17), and prostaglandin E2 (PGE2) were evaluated at the end of the treatment period. Both arthritic index and paw thickness were markedly improved in CIA + quetiapine treatment group compared with those in CIA groups (arthritic index; P < 0.01, paw thickness; P < 0.05). Radiologic assessment revealed decreased cartilage damage and bone erosion in CIA + quetiapine treatment group compared with those in CIA groups. Articular cartilage destruction observed in CIA group was not found in CIA + quetiapine group. The concentrations of anti-type II collagen-specific antibody, IL-6, IL-17, and PGE2 in CIA + quetiapine group were significantly lower than those in CIA groups (P < 0.05). Weight gain which is commonly observed with the treatment of antipsychotics was not observed. Taken together, these results suggest that quetiapine shows anti-inflammatory effects in murine collagen-induced arthritis.