MPO and colitis: The levels of COX, MPO, and PGE2 in the colon tissue significantly increased in animals with induced colitis fed with feed without beta-glucans (CβG- vs. HβG-) at both time points; however, a significantly greater increase in COX levels was found at 7 days, while a significantly greater increase in MPO and PGE levels was observed at 3 days after TNBS administration.