Curcumin is a tumeric-derived, water-insoluble polyphenol with potential beneficial health effects for humans. It has been shown to have preventive as well as therapeutic effects in chemically induced murine models of colitis. To investigate whether curcumin exerts a similar effect on the spontaneous colitis in interleukin (IL)-10 gene-deficient mice, we gavaged these mice daily for 2 weeks with 200 mg/kg per day curcumin emulsified in carboxymethyl cellulose, a food additive generally used as a viscosity modifier. Mice fed the curcumin/carboxymethyl cellulose mixture and those receiving carboxymethyl cellulose alone demonstrated similar reductions in histological injury score and colon weight/length ratio compared to water-fed controls. However, significant reductions in pro-inflammatory cytokine release in intestinal explant cultures were only seen in mice treated with the curcumin mixture. Our data demonstrate that in IL-10 gene-deficient mice, both oral curcumin and carboxymethyl cellulose, appear to have modifying effects on colitis. However, curcumin has additional anti-inflammatory effects mediated through a reduced production of potent pro-inflammatory mucosal cytokines.