The Effects of <italic>Mannyeon-hwan</italic> on Acetic Acid-induced Ulcerative Colitis in Rats

Objectives: This study was designed to verify the effects of <i>Mannyeon-hwan</i> (MNH) on acetic acid-induced ulcerative colitis in rats.Methods: Ulcerative colitis was induced in male Sprague-Dawley rats weighing approximately 250 g by injecting acetic acid through the anus. Rats were classified into four groups: normal group, control group (acetic-acid, AA), low concentration group (AA+MNH(L)), and high concentration group (AA+MNH(H)). Body weight, visual evaluation of the colonic mucosa, anatomical histological changes, and changes in the expression of proteins in colon tissue were compared and analyzed.Results: Compared to the control group, the MNH groups showed significant recovery from weight loss and mucosal damage. The expression of inflammatory proteins such as TNF-α, IL-6, IL-1β, NF-κB p65, MPO, and COX-2 were significantly decreased in the MNH groups compared to those in the AA group. In the MNH groups, significant changes in proteins involved in apoptosis such as caspase-3, BAX, and Bcl-2 were observed compared to those in the AA group. Additionally, changes in the expression of TNF-α, IL-6, IL-1β, NF-κB p65, BAX, and Bcl-2 were greater in the MNH(H) group than those in the MNH(L) group.Conclusion: <i>Mannyeon-hwan</i> was found to be effective in suppressing inflammation of the colonic mucosa in ulcerative colitis, inhibiting the expression of inflammation-related proteins, and suppressing damage to the colonic mucosa by regulating the expression of apoptosis-related proteins.