Background & aims: Increased intestinal permeability is one of the grastointestinal changes observed in alcoholic patients. However, there are no objective definitions as yet of how alcohol induces pathological changes in the various organs. The action of oxygen-free radicals during ethanol metabolism has been considered a determinant factor of these alterations. The present study was undertaken to determine the effect of niacin supplementation on intestinal permeability and oxidative stress in patients with alcoholic pellagra.
Methods: The study was divided into two phases: in Phase 1 we studied ten patients with pellagra before treatment with niacin, and in Phase 2 we studied the same patients after 27 days of treatment with niacin. Intestinal permeability was assessed by the (51)CrEDTA test and the antioxidant action of niacin supplementation was assessed by the determination of lipid peroxidation (plasma malondialdehyde, MDA), protein oxidation (plasma carbonyl group) and of the antioxidants plasma vitamin E and erythrocyte glutathione peroxidase.
Results: Comparison of intestinal permeability by the (51)CrEDTA test before and after niacin treatment showed a significant decrease in permeability from 4.29+/-1.92% to 1.90+/-1.19% (P<0.05). Assessment of oxidative stress showed a significant decrease (P<0.05) in lipid and protein peroxidation (MDA: 1.19+/-0.40-0.89+/-0.27 micromol/l; carbonyl groups: 2.22+/-0.36-1.84+/-0.40 nmol/mg protein).
Conclusions: The results suggest that niacin and vitamin E deficiency in patients with pellagra could be important factors in increased intestinal permeability and decreased antioxidant conditions, recovering to normal values after treatment with niacin, associated to alcohol abstinence and a balanced diet.