Abstract: 

Many experimental studies have analyzed the damaging effects of oxidative stress on epithelial cells and in particular on intestinal luminal epithelia (alterations in permeability). The "in vitro" system most used to reproduce these qualities (morphologic and functional) and to observe the response under oxidative stress conditions is the cell line of human adenocarcinoma of the colon (Caco-2). These cell lines have been select for studies on oxidative stress because on histological analysis this cell architecture is similar to that of human adult colon epithelia. In fact this cell line is comprised precisely of at least 3 cytotypes some cells appear biochemical enzymatically typical of a normal adult intestine, others of the fetal colon and still others as those of normal adult colon. In this study Caco-2 cell lines are been used to show the effects that the antioxidant /pro-oxidant capacity and on possible morphological and physical/chemical changes induced by oxidant and antioxidant substance 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) and the a-tocopherol, on the cultural epithelium. The analyses morphological and chemical/physical measurement through histological analysis and Trans Epithelial Electrical Resistance (TEER). The results have shown that the a-tocopherol has antioxidant characteristics in presence of AAPH, while it is becoming hydrophilic pro-oxidant, when used alone or to elevated concentrations (0,30-0,40mg/ml).The chemical/physical measurement and histological analysis have shown that the cellular changes are tied to the antioxidant capacity of the cultural medium.