Oxidative stress in familial adenomatous polyposis

The prooxidant/antioxidant imbalance in familial adenomatous polyposis (FAP ) is suggested by (i) the intimate connection between APC and prostaglandin H synthase-2 genes, (ii) the increase of the free radical-generating enzym e xanthine oxidase, and (iii) the decrease of antioxidant defences. In this research work we evaluated lipid peroxidation measuring the thiobarbituric acid (TBA) reactive products and we studied the activities of superoxide d ismutase (SOD) and catalase as well as the levels of ascorbate and tocopher ols in the peripheral blood cells from a total of 27 FAP patients and 83 no rmal controls. TBA-reactive products were determined according to a previou sly published method. SOD and catalase activities were determined by the sp ectrophotometric monitoring of the inhibition of pyrogallol autoxidation an d the hydrogen peroxide decomposition rate, respectively. Ascorbate levels were determined by a modified 2,4-dinitrophenylhydrazine method and tocophe rol levels by a modified Emmerie-Engle method. The levels of TBA-reactive p roducts were higher in FAP patients than in normal controls. Although no st atistically significant differences in SOD and catalase activities were obs erved between FAP patients and normal controls, we found that ascorbate and tocopherol levels were significantly lower in FAP patients than in normal controls, as assessed by the Mann-Whitney test. Hence, this finding of an i mbalance in the prooxidant/antioxidant status may contribute towards new st rategies for prevention and therapy in FAP patients. (C)1999 Lippincott Wil liams & Wilkins.