Chinese Herbal Medicine for Irritable Bowel Syndrome: A Perspective of Local Immune Actions

Irritable bowel syndrome (IBS) is the functional gastrointestinal disorder, characterized by abdominal pain and altered bowel habits. The interest in intestinal immune activation as a potential disease mechanism for IBS has increased exponentially in recent years. This study was designed to summarize the Chinese herbal medicine (CHM) that potentially exert protective effects against IBS through inhibition of intestinal immune activation. We detailed the current evidence that immune activation contributes to the pathology of IBS and discussed the potential mechanisms involved. Then, therapeutic effects and possible mechanisms related to immune response of herbal medicine prescriptions, extracts, and monomers were analyzed. The reasons leading to the aberrant and persistent immune activation noted in IBS are mainly associated with the increased number of mast cells, CD3[Formula: see text] T cells, and CD4[Formula: see text] T cells. The mechanisms mainly focused on the gut microbiota disorder induced alteration of the PGE2/COX2/SERT/5-HT, TLR4/MyD88/NF-κB, and BDNF/TrkB pathways. Most of the CHM alleviated IBS through interventions of intestinal immune activation via gut microbiota related to the TLR4/MyD88/NF-κB and SCF/c-kit pathways. We hope this review will provide some clues for the further development of novel candidate agents for IBS and other intestinal immune disorders.