ANTIOXIDANTS, HELICOBACTER-PYLORI AND STOMACH-CANCER IN VENEZUELA

A randomized chemoprevention trial on precancerous lesions of the stom ach is being conducted in Tachira State, Venezuela, The aims of the st udy are to evaluate the efficacy of vitamin supplementation in prevent ing the progression rate of precancerous lesions, Here we report on th e pilot phase of the study in which two antioxidant preparations were evaluated on their ability to raise antioxidant levels in plasma and i n gastric juice, The study aimed also to determine the antibiotic sens itivity profiles of Helicobacter pylori isolates prevalent in the area , Forty-three subjects with precancerous lesions (chronic gastritis, c hronic atrophic gastritis, intestinal metaplasia and dysplasia) of the stomach were randomized to one of two antioxidant treatments, Treatme nt 1 (250 mg of standard vitamin C, 200 mg of vitamin E and 6 mg of be ta-carotene three times a day) or treatment 2 (150 mg of standard vita min C, 500 mg of slow release vitamin C, 75 mg of vitamin E and 15 mg of beta-carotene once a day) for 7 days, Blood levels of total vitamin C, beta-carotene and alpha-tocopherol and gastric juice levels of asc orbic acid and total vitamin C were measured before and after treatmen t on day 8. Both treatments increased the plasma levels of total vitam in C, beta-carotene and alpha-tocopherol/cholesterol but not those of ascorbic acid or total vitamin C in gastric juice, Treatment 1 was the best choice and resulted in a greater increase in the plasma levels o f beta-carotene and beta-tocopherol. H. pylori was cultured from 90% o f the gastric biopsies; 35 isolates were identified which were highly resistant to metronidazole, a front-line antibiotic recommended agains t H. pylori in other settings.