PTGS2 and ulcerative colitis: In 2,4,6-trinitrobenzenesulfonic acid (TNBS) induced ulcerative colitis rats, Wumeiwan could alleviate colonic tissue damage and improve disease activity index (DAI), the mechanisms might be related to reducing the levels of myeloperoxidase (MPO) activity, IL-6, and TNF-α, and decrease the expression of cyclooxygenase-2 (COX-2) protein (Ma et al., 2021).