REACTIVE OXYGEN SPECIES ACTIVITY AND LIPID-PEROXIDATION IN HELICOBACTER-PYLORI-ASSOCIATED GASTRITIS - RELATION TO GASTRIC-MUCOSAL ASCORBIC-ACID CONCENTRATIONS AND EFFECT OF HELICOBACTER-PYLORI ERADICATION

Background-Helicobacter pylori is an independent risk factor for gastr ic cancer, and this association may be due to the bacterium causing re active oxygen species mediated damage to DNA in the gastric epithelium , High dietary ascorbic acid intake may protect against gastric cancer by scavenging reactive oxygen species. Aims-To assess reactive oxygen species activity and damage in gastric mucosa in relation to gastric pathology and mucosal ascorbic acid level, and to determine the effect of H pylori eradication on these parameters. Patients-Gastric biopsy specimens were obtained for analysis from 161 patients undergoing endo scopy for dyspepsia. Methods-Reactive oxygen species activity and dama ge was assessed by luminol enhanced chemiluminescence and malondialdeh yde equivalent estimation respectively. Ascorbic acid concentrations w ere measured using HPLC. Results-Chemiluminescence and malondialdehyde levels in gastric mucosa were higher in patients with H pylori gastri tis than in those with normal histology. Successful eradication of the bacterium led to decreases in both parameters four weeks after treatm ent was completed. Gastric mucosal ascorbic acid and total vitamin C c oncentrations were not related to mucosal histology but correlated wea kly with reactive oxygen species activity (chemiluminescence and malod ialdehyde levels). Conclusions-Data suggest that reactive oxygen speci es play a pathological role in H pylori gastritis, bur mucosal ascorbi c acid is not depleted in this condition.