An essential point of cytoprotection is that the prostaglandins are able to prevent chemical-induced gastric mucosal damage without affecting gastric acid secretion, this being originally suggested as a property specific to prostaglandins. Since then gastrointestinal cytoprotection has been shown with various agents (anticholinergic agents, H(2)RA, growth factors) and retinoids the latter differing from the actions of vitamin A. In examining the various components of gastrointestinal cytoprotection we have performed studies in isolated cells, stable cell lines, animal experiments, healthy human subjects, and in patients with gastrointestinal diseases. Our attention has focused on the effects of cytoprotective agents on cellular viability, mitochondrial and DNA damage, oxygen free radicals, natural antioxidant systems, mucosal biochemistry, vascular events, gastrointestinal mucosal protection as well as in their prevention of different human diseases. This paper gives a short overview on the different approaches for the exploring gastrointestinal cytoprotection.