Dimethyl Fumarate Suppresses Collagen-Induced Arthritis by Regulating Inflammatory Responses.

Dimethyl fumarate (DMF) is approved for treating autoimmune and inflammatory diseases; however, its effectiveness in rheumatoid arthritis (RA) has not been thoroughly studied. This study used a collagen-induced arthritis (CIA) rat model to evaluate the effects of DMF on RA in vivo. Lewis rats were used to create an arthritis model using bovine type II collagen (CII) emulsified with incomplete Freund's adjuvant (IFA). Five groups of rats were randomly selected: vehicle-treated rats, DMF-treated rats, CIA-controlled rats, normal control rats, and methotrexate (MTX)-treated rats. Arthritis score and the measurement of hind paw swelling were measured as part of the clinical evaluation. Rats were sacrificed on day 28, and the hind ankle joints were collected for radiography and histological analysis. ELISA was also used to measure the plasma levels of tumor necrosis factor alpha (TNF-α) and anti-CII. DMF significantly reduced joint inflammation, cartilage degradation, CIA-induced arthritis score, and hind paw swelling. TNF-α and anti-CII levels were lower in the DMF-treated group than in the CIA control group. The immunoregulatory activity of DMF may have contributed to its amelioration of RA. DMF might be studied as a possible new medicinal agent for the treatment of RA.