The protein expression data of AA-induced ulcerative colitis demonstrate upregulation Cox-2, PGE2 and iNOS protein expression that leads to inflammation edema and intestinal hyperemia of the colon epithelium as compared to the normal colon; however, SA and PDRL pretreatment significantly suppressed the Cox-2, PGE2 and iNOS overexpression, probably due to suppression of ROS/RNS and restoration of antioxidative system and suppression of cytokines (TNF α, IL 6 and MPO), apoptotic injuries to the colon epithelium. Here, MPO is linked to ulcerative colitis.