Effects of co-treatment with pioglitazone and methotrexate on experimentally induced rheumatoid arthritis in Wistar albino rats

OBJECTIVES Rheumatoid arthritis (RA) is a chronic inflammatory disease primarily affecting the synovial joints of the body. Methotrexate (MTX) is considered as a mainstay in the management of RA. However, monotherapy with MTX in RA is often limited by potential long-term toxicity. The present study was conducted to evaluate if MTX-pioglitazone combination therapy has an add-on benefit over monotherapy with MTX or pioglitazone on disease activity in male Wistar rats in adjuvant-induced arthritis model. MATERIALS AND METHODS Arthritis was induced by single subcutaneous injection of complete Freund's adjuvant (CFA) in thirty male Wistar albino rats. They were then divided into five equal groups, which included two control groups (arthritic and nonarthritic), pioglitazone-treated (1.35 mg/kg daily), MTX-treated (0.225 mg/kg daily), and MTX + pioglitazone-treated. The disease-modifying action of the drugs was assessed by various physiological, hematological, and biochemical parameters along with histopathological and radiological analysis of affected joints. The experimental data were statistically assessed by one-way ANOVA. RESULTS There was a significant reduction of disease activity in the MTX monotherapy group when compared with disease control. However, pioglitazone monotherapy group failed to demonstrate any significant effect on disease activity. The MTX-pioglitazone combination group demonstrated greater suppression of disease activity as compared to MTX and pioglitazone monotherapy and disease control group (P < 0.05). CONCLUSION The present study demonstrates that the combination therapy of MTX with pioglitazone offers better control of disease activities in RA as compared to MTX or pioglitazone monotherapy.