Effect of immunostimulatory ribomunyl on the preventive treatment of rat adjuvant arthritis with cyclosporine and methotrexate

Abstract

Objective: To study the effects of ribomunyl, an oral ribosomal immunostimulant frequently used to prevent recurrent oropharyngeal and bronchopulmonary infections in children and adults, on adjuvant arthritis as well as its effect on methotrexate and cyclosporine treatment.

Methods: Rats with adjuvant induced arthritis were preventively treated orally with the following drugs: cyclosporin A (CSA, 2.5 mg/kg/day); ribomunyl (RIB, 25 mg/kg/day, 4 days a week); methotrexate (MTX, 0.6 mg/kg/week), and the combinations CSA + RIB, MTX + RIB, CSA + MTX, CSA + MTX + RIB for the period of 50 days from adjuvant application. Levels of serum albumin, serum nitrite/nitrate concentrations, hind paw swelling, arthrograms, and bone destruction were measured in rats as variables of the inflammation and destructive arthritis associated changes.

Results: Preventive treatment with low doses of CSA and MTX significantly inhibited both markers of inflammation and arthritis. The combination CSA + MTX was more effective on all evaluated measures than any of its components alone. RIB alone improved arthrogram scores and decreased serum nitrite/nitrate concentrations in arthritic rats. The combination of RIB with the low dose of CSA or MTX enhanced the beneficial effects of these drugs. The best preventive effect was observed with the combination of 3 agents, CSA + MTX + RIB.

Conclusion: Our results show ribomunyl to have the potential to improve some inflammation and arthritis associated changes in rat adjuvant arthritis and to enhance the preventive effect of MTX and CSA and their combination.