title: Antioxidant enzymes and human diseases.
abstract: OBJECTIVE
  To describe the importance of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, and catalase working together in human cells against toxic reactive oxygen species, their relationship with several pathophysiologic processes and their possible therapeutic implications.
  
  
  CONCLUSIONS
  Reactive oxygen species (ROS) are involved in the cell growth, differentiation, progression, and death. Low concentrations of ROS may be beneficial or even indispensable in processes such as intracellular signaling and defense against micro-organisms. Nevertheless, higher amounts of ROS play a role in the aging process as well as in a number of human disease states, including cancer, ischemia, and failures in immunity and endocrine functions. As a safeguard against the accumulation of ROS, several nonenzymatic and enzymatic antioxidant activities exist. Therefore, when oxidative stress arises as a consequence of a pathologic event, a defense system promotes the regulation and expression of these enzymes.
authors.affiliation: Department of Molecular Biology and Biochemistry, Faculty of Sciences, University of Málaga, Spain. jmates@uma.es
authors.forename: J M
authors.initials: JM
authors.lastname: Matés
authors.forename: C
authors.initials: C
authors.lastname: Pérez-Gómez
authors.forename: I
authors.initials: I
authors.lastname: Núñez de Castro
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism*; D004194:Disease; D005979:Glutathione Peroxidase / Q000378:metabolism*; D006801:Humans; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase