Anti-arthritic and anti-inflammatory activity of combined pioglitazone and prednisolone on adjuvant-induced arthritis.

The aim of the present study was to evaluate the effect of combined treatment of pioglitazone (PGZ) and prednisolone (PDL) on the progression of adjuvant-induced arthritis in rats. Adjuvant arthritis was induced by single intra-dermal injection of 0.1 ml Freund's complete adjuvant (0.05% w/v Mycobacterium butyricum in mineral oil) into foot pads of left hind paws of Wistar rats of either sex. There were six experimental groups: Group I was healthy animals as control, Group II was arthritic animals without drug treatment, Group III was arthritic animals treated with a standard non-steroidal anti-inflammatory drug aspirin (100 mg/kg), Group IV was arthritic animals received PGZ (10 mg/kg) alone, Group V was arthritic animals received PDL (10 mg/kg) alone, and Group VI was arthritic animals treated with a combined suspension of PGZ and PDL (20 mg/kg). Drugs were administered daily orally at day 0 and continued upto 28th day after induction of arthritis. Induction of arthritis significantly increased hind paw volume (HPV), loss of body weight (BW), enhanced tibiotarsal joint thickness (TJT), and increased plasma tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 levels. Treatment with aspirin or combined suspension of PGZ and PDL in the arthritic animals produced significant reductions in HPV and TJT, normalized BW, and significantly decreased plasma levels of TNF-α and IL-6. These observations suggest that the combined administration of PGZ and PDL was effective in modulating the inflammatory response and suppress arthritis progression in experimental animal model. These findings may help to improve the treatment of rheumatoid arthritis.