Angelica gigas Nakai hot water extracts alleviate IL-6-induced ulcerative colitis by restoring intestinal barrier function

Abstract

BackgroundInflammatory bowel disease (IBD) is a chronic disease that includes Crohn's disease and ulcerative colitis (UC). Tight junctions (TJs) play an important role in intestinal barrier function. In intestinal epithelial cells, TJs are composed of different junction molecules, including claudin and occludin (OCLN), and regulate the paracellular permeability of water, ions, and macromolecules in adjacent cells. The TJ structure also provides a physical barrier to luminal inflammatory molecules, although impaired integrity and structure of the TJ barrier can result in the forcible activation of immune cells and inflammation.ObjectiveThis study aimed to investigate the protective effects of Angelica gigas Nakai extracts (AGNE) on intestinal barrier and TJ activation.ResultsAGNE exhibited no cytotoxic activity against Caco-2 cells and showed potent antioxidant activity. Moreover, AGNE treatment significantly increased transepithelial electrical resistance (TEER) values and reduced epithelial permeability. In addition, the expression of Zonula Occludens (ZO)-1 and OCLN increased in a concentration-dependent manner with AGNE treatment. Conversely, myosin light chain kinase (MLCK) expression decreased in a concentration-dependent manner upon AGNE treatment. Notably, the most significant improvement was observed in the AGNE 200 mu g/mL group compared to the IL-6 control group.ConclusionOur findings highlight the potential usefulness of AGNE as a novel therapeutic agent for maintaining epithelial barrier integrity in IBD.