Comparative Effects of Curcumin and Tetrahydrocurcumin on Dextran Sulfate Sodium-induced Colitis and Inflammatory Signaling in Mice

BACKGROUND: Curcumin, a yellow ingredient of turmeric (Curcuma longa Linn, Zingiberaceae), has long been used in traditional folk medicine in the management of inflammatory disorders. Although curcumin has been reported to inhibit experimentally-induced colitis and carcinogenesis, the underlying molecular mechanisms remain largely unresolved. METHODS: Murine colitis was induced by dextran sulfate sodium (DSS) which mimics inflammatory bowel disease. Curcumin or tetrahydrocurcumin was given orally (0.1 or 0.25 mmol/kg body weight daily) for 7 days before and together with DSS administration (3% in tap water). Collected colon tissue was used for histologic and biochemical analyses. RESULTS: Administration of curcumin significantly attenuated the severity of DSS-induced colitis and the activation of NF-κB and STAT3 as well as expression of COX-2 and inducible nitric oxide synthase. In contrast to curcumin, its non-electrophilic analogue, tetrahydrocurcumin has much weaker inhibitory effects. CONCLUSIONS: Intragastric administration of curcumin inhibited the experimentally induced murine colitis, which was associated with inhibition of pro-inflammatory signaling mediated by NF-κB and STAT3.