Anti-inflammatory effect of interleukin-10 in rabbit immune complex-induced colitis

Background: Interleukin-10 (IL-10) is an anti-inflammatory cytokine that downregulates the secretion of pro-inflammatory cytokines and additionally induces the secretion of anti-inflammatory cytokines, thus possibly leading to reduction of chronic inflammation in inflammatory bowel disease. In this study we evaluated the anti-inflammatory effect of IL-10 in a model of acute colitis in rabbits. Methods: Colitis was induced by rectal instillation of formalin, 0.65%, followed by intravenous infusion of 0.85 mi heat-aggregated rabbit immunoglobulin. Rabbits were treated with an intravenous bolus of recombinant human LL-IO (SCH52000), 100 mu g/kg (n = 14) or 500 mu g/kg (n = 14), 1 h before induction of colitis (control group, n = 12). Results: High-dose IL-10 improved macroscopic scores of inflammation and decreased tissue myeloperoxidase levels and Ieukotriene B-4 levels in dialysate fluid. Thromboxane B-2 and prostaglandin E-2 levels remained unaffected. Conclusion: IL-10 ameliorates acute colitis in this model. Consequently, this anti-inflammatory cytokine may have a role in the therapy of acute inflammatory bowel disease