title: Generation of reactive oxygen species by the faecal matrix.
abstract: 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.
  
  
  OBJECTIVE
  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.
authors.affiliation: Division of Toxicology and Cancer Risk Factors, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany.
authors.forename: R W
authors.initials: RW
authors.lastname: Owen
authors.forename: B
authors.initials: B
authors.lastname: Spiegelhalder
authors.forename: H
authors.initials: H
authors.lastname: Bartsch
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D001419:Bacteria / Q000378:metabolism; D002396:Catechols / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004492:Edetic Acid / Q000494:pharmacology; D005243:Feces / Q000737:chemistry* / Q000382:microbiology; D016166:Free Radical Scavengers / Q000494:pharmacology; D005841:Gentisates; D006801:Humans; D062385:Hydroxybenzoates / Q000032:analysis; D017665:Hydroxyl Radical / Q000378:metabolism; D019271:Hypoxanthine / Q000378:metabolism; D010833:Phytic Acid / Q000494:pharmacology; D017382:Reactive Oxygen Species; D020156:Salicylic Acid / Q000378:metabolism; D014969:Xanthine Oxidase / Q000378:metabolism
chemical_list: D002396:Catechols; D016166:Free Radical Scavengers; D005841:Gentisates; D062385:Hydroxybenzoates; D017382:Reactive Oxygen Species; D019271:Hypoxanthine; D017665:Hydroxyl Radical; C009135:2,3-dihydroxybenzoic acid; D010833:Phytic Acid; D004492:Edetic Acid; D014969:Xanthine Oxidase; D020156:Salicylic Acid; D001205:Ascorbic Acid; C010925:2,5-dihydroxybenzoic acid