Generation of reactive oxygen species by the faecal matrix

• Published in: Gut Vol. 46; no. 2; pp. 225 - 232
• Main Authors: Owen, R W, Spiegelhalder, B, Bartsch, H
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Society of Gastroenterology 01.02.2000; BMJ; BMJ Publishing Group LTD
• Subjects: Ascorbic Acid - pharmacology; Bacteria - metabolism; Biological and medical sciences; Catechols - analysis; Chromatography, High Pressure Liquid - methods; colorectal cancer; Deoxyribonucleic acid; Diet; DNA; Edetic Acid - pharmacology; faecal matrix; Fatty acids; Feces - chemistry; Feces - microbiology; Free Radical Scavengers - pharmacology; Free radicals; Gastroenterology. Liver. Pancreas. Abdomen; Gentisates; Humans; Hydroxybenzoates - analysis; Hydroxyl Radical - metabolism; Hypotheses; hypoxanthine; Hypoxanthine - metabolism; Iron; Lipid peroxidation; Medical sciences; Oxygen; phytic acid; Phytic Acid - pharmacology; Reactive Oxygen Species; Salicylic Acid - metabolism; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Studies; Tumors; xanthine oxidase; Xanthine Oxidase - metabolism; Germany; Human; Rectal disease; Pathogenesis; Cell biology; Biosynthesis; Malignant tumor; Chromatography; Colonic disease; Rectum; Digestive diseases; Intestinal disease; Colon; Hydroxyl
• ISSN: 0017-5749; 1468-3288; 1458-3288
• DOI: 10.1136/gut.46.2.225

BACKGROUND Reactive oxygen species are implicated in the aetiology of a range of human diseases and there is increasing interest in their role in the development of cancer. AIM To develop a suitable method for the detection of reactive oxygen species produced by the faecal matrix. METHODS A refined high performance liquid chromatography system for the detection of reactive oxygen species is described. RESULTS The method allows baseline separation of the products of hydroxyl radical attack on salicylic acid in the hypoxanthine/xanthine oxidase system, namely 2,5-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, and catechol. The increased efficiency and precision of the method has allowed a detailed evaluation of the dynamics of reactive oxygen species generation in the faecal matrix. The data show that the faecal matrix is capable of generating reactive oxygen species in abundance. This ability cannot be attributed to the bacteria present, but rather to a soluble component within the matrix. As yet, the nature of this soluble factor is not entirely clear but is likely to be a reducing agent. CONCLUSIONS The soluble nature of the promoting factor renders it amenable to absorption, and circumstances may exist in which either it comes into contact with either free or chelated iron in the colonocyte, leading to direct attack on cellular DNA, or else it initiates lipid peroxidation processes whereby membrane polyunsaturated fatty acids are attacked by reactive oxygen species propagating chain reactions leading to the generation of promutagenic lesions such as etheno based DNA adducts.