Vasoactive intestinal peptide as a healing mediator in Crohn's disease.

The vasoactive intestinal peptide/pituitary adenylate cyclase-activating peptide (VIP/PACAP) system is considered as a paradigm for the use of a neuroendocrine-immune mediator in therapy. We review the role of VIP in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis as a murine model of Crohn's disease. VIP treatment led to the recovery of clinical factors, the amelioration of parameters related to the recruitment and traffic of cell populations, and the balance of inflammatory mediators derived from granulocytes, antigen-presenting cells and T lymphocytes including Th1, Th2 and Th17. Finally, the most recent data validate its therapeutic role through the modulation of TLR2 and 4 receptors.