There is increasing interest in the use of combination therapy for rheumatoid arthritis and in the possibility of combining the conventional drug approach with newer antirheumatic therapy. The present study investigates the efficacy of long-term prophylactic enzyme therapy and combination therapy with cyclosporin A in rats with collagen-induced arthritis.
Rats with collagen-induced arthritis were administered the following drugs: cyclosporin A (5 mg/kg/day and 10 mg/kg/day orally); a mixture of enzymes containing pure substances (bromelain, trypsin, rutin) in the same ratio as in Phlogenzym (PHL, 150 mg/kg, twice daily intrarectally); and a combination of 5 mg/kg/day cyclosporin A plus 300 mg/kg/day PHL for a period of 50 days from the immunization. Levels of serum albumin, serum nitrite/nitrate concentrations, changes in hind paw swelling and bone erosions were measured in the rats as variables of inflammation and destructive arthritis-associated changes.
Treatment with 10 mg/kg cyclosporin A, as well as combination therapy with half dosages of cyclosporin A (5 mg/kg) plus PHL significantly inhibited both inflammation and destructive arthritis-associated changes. Significant differences in favor of combination therapy with 5 mg/kg CsA + 300 mg/kg PHL as compared to 5 mg/kg CsA alone were seen in hind paw swelling. Also, reduction of the radiographic scores was more significant in the combination therapy group. Five mg cyclosporin A or PHL alone reduced the disease markers studied to a lesser extent, and in the case of enzyme therapy this occurred at a later stage of arthritis development.
Our results show the inhibitory effect of enzyme therapy on collagen-induced arthritis in rats, as well as the efficacy of cyclosporin A given in low doses in combination with enzyme therapy, which may be useful in the treatment of rheumatoid arthritis.