TNF and colitis: These results show that the oxidative stress and the redox imbalance that occurred during TNFα-induced colitis are associated with an increase in the activities of the redox-sensitive MAP kinases, ERK1/2, p38MAPK, and JNK in the colon, and that only the activation of p38MAPK and ERK1/2 was prevented by the NADPH oxidase inhibitor and ROS scavenger, apocynin.