Anti-inflammatory effect of bee venom on antigen-induced arthritis in rabbits: influence of endogenous glucocorticoids.

AIM OF THE STUDY This study assessed the involvement of endogenous glucocorticoids (GCs) in the anti-arthritic properties of bee venom (BV) on antigen-induced arthritis (AIA) in rabbits. MATERIALS AND METHODS BV (1.5-6 microg/kg/day) was injected for 7 days before AIA induction, whereas the control group received sterile saline. The total and differential leukocyte count, PGE(2) levels in synovial fluid and synovial membrane cell infiltrate were evaluated. The contribution of GCs to BV action was assessed in rabbits treated with BV plus metyrapone, an inhibitor of GC synthesis, or RU-38 486, a steroid antagonist. RESULTS Treatment with BV (1.5 microg/kg/day) reduced the leukocyte count and PGE(2) level (18571+/-1909 cells/mm(3) and 0.49+/-0.05 ng/mL, respectively) as well as the cellular infiltrate compared with the control group (40968+/-5248 cells/mm(3) and 2.92+/-0.68 ng/mL, p<0.05). The addition of metyrapone to BV treatment completely reversed the inhibition of AIA, whereas RU-38 486 was ineffective. CONCLUSION Our data show that bee venom treatment prevents the development of antigen-induced arthritis in rabbits through the action of GCs.