Article Type

Original Study


Objective To investigate the effect of pentoxifylline (PTX) and pioglitazone (Pg), each alone and in combination with methotrexate (MTX), on rheumatoid arthritis (RA) induced experimentally in male albino rats. Background Individuals have long feared RA as one of the most disabling types of arthritis. It is estimated that over 46 million individuals have arthritis, ~1% worldwide. Material and methods One hundred and eighty adult male albino rats were used in the present study. MTX was administered intraperitoneally at a dose of 0.25 mg/kg daily. PTX was administered intraperitoneally at a dose of 150 mg/kg/rat/day, whereas Pg was administered orally at a dose of 3 mg/kg/day. All doses were administered for a period of 2 weeks. RA was induced by two methods: adjuvant-induced arthritis and pristane-induced arthritis (PIA). Adjuvant-induced arthritis was induced by an intradermal injection of 0.1 ml of complete Freund adjuvant. This type of arthritis appears about 8-12 days after injection. PIA was induced by a single intradermal injection with 0.2 ml pristane at the base of the tail. PIA develops in 2-3 weeks after injection and progresses with a relapsing course that persists for months. Results The anti-inflammatory properties of these drugs were confirmed by reduction of erythrocyte sedimentation rate, serum rheumatoid factor level, serum C-reactive protein level, serum tumor necrosis factor-a level, serum nitrite level, and blood superoxide dismutase level, whereas antioxidant activities were confirmed by an increase in the blood reduced glutathione level. Our study showed that Pg alone exerts portentous effects in the treatment of RA. However, it was more active in combination with MTX. Conclusion Our study showed that Pg was the most potent drug in treating arthritic rats, followed by PTX, with lesser potency in treating arthritic rats. When comparing the two combinations, the combination of Pg with MTX was the most potent one. The second combination was the combination of PTX with MTX.