XN protects mice from DSS-induced colitis and H2O2- or LPS-treated IEC-6 injury, possibly by the interaction between the α, β-unsaturated carbonyl moiety of XN and Cys99 in IKKβ, and thus by its ability to inhibit the IKKβ/NF-κB signaling pathway. Here, NFKB1 is linked to colitis.