Curcumin represses the activity of inhibitor-κB kinase in dextran sulfate sodium-induced colitis by S-nitrosylation

- Curcumin alleviates the DSS-induced colitis.
- Curcumin reduces the production of inflammatory factors and nitrite formation.
- Protein S-nitrosylation can be protected by curcumin in colonic inflammation.
- The activity of IKK and NF-κB may be regulated by curcumin-mediated S-nitrosylation.

In this study, we investigated the preventive effects of curcumin using dextran sulfate sodium (DSS)-induced colitis and the potential role of curcumin in regulation of anti-inflammation through S-nitrosylation. After curcumin treatment for 6 days, the body weight and disease activity index of DSS-induced mice was alleviated and the colonic length was also rescued. Western blot presented that the protein expression of iNOS can be reduced by curcumin. Consistently, mRNA level of iNOS and pro-inflammatory cytokines, such as TNFα, IL-1β, and IL-6, was also repressed. Moreover, Curcumin reduced the amount of nitrite in DSS-induced colitis but not affected total S-nitrosylation level on proteins on day 6, indicating that curcumin inhibited NO oxidation. Furthermore, the protection of S-nitrosylation on IKKβ in DSS-induced colitis for 6 days by curcumin caused the repression of IκB phosphorylation and NF-κB activation. In conclusion, this study verified that curcumin-mediated S-nitrosylation may be as an important regulator for anti-inflammation in DSS-induced colitis of mice.