Paclitaxel suppresses collagen-induced arthritis: a reevaluation

Objective: To reevaluate the suppressive effect of paclitaxel (PTX) liposome on collagen-induced arthritis (CIA) in rats and explore its mechanisms. Methods: Female Lewis rats were immunized with bovine type II collagen (CII) to induce arthritis. The rats with CIA were randomly divided into three groups: 5% GS control group, 2.5 mg/kg PTX treatment group and 1 mg/kg methotrexate (MTX) positive control group. The drugs were administered by intraperitoneal injection on the second day after arthritis onset. The body weights, arthritis scores and paw volumes were observed consecutively. The ankle joints of rats were collected for X-ray examination and histological evaluation. Serum samples were collected to test the levels of anti-CII antibodies and cytokines. Results: Body weights were not significantly affected after PTX or MTX treatments (p>0.05). Compared with 5% GS control or MTX treatment groups, PTX group showed significant decrease of arthritis scores and paw volumes (p<0.05). Radiographic and histologic evaluation provided evidence that rats with PTX treatment had less synovial proliferation and bone erosion. In addition, the levels of anti-CII antibodies as well as serum tumor necrosis factor (TNF)-alpha and vascular endothelial growth factor (VEGF) levels were remarkably lower in PTX group than those in 5% GS controls (p<0.05). Conclusions: PTX inhibits the progression of CIA in rats and prevents the destruction of joints. The mechanism might be related to its inhibition on the levels of serum anti-CII antibodies, TNF-alpha and VEGF.