SOD1 and colitis: By mediating the degradation of Keap1 in the cytoplasm, Nrf2/HO-1 signaling is activated, further significantly increasing the activities of the antioxidant enzymes SOD and GSH-Px, reducing the activities of myeloperoxidase (MPO) and MDA and caspase-3, and inhibiting the levels of the proinflammatory cytokines IL-6, TNF-α and IL-1β in colitis (56, 57).