title: Roles of reactive oxygen species and selected antioxidants in regulation of cellular metabolism.
abstract: Reactive oxygen species (ROS) are essential for life of aerobic organisms. They are produced in normal cells and formed as a result of exposure to numerous factors, both chemical and physical. In normal cells, oxygen derivatives are neutralized or eliminated owing to the presence of a natural defense mechanism that involves enzymatic antioxidants (glutathione peroxidase, superoxide dismutase, catalase) and water or fat-soluble non-enzymatic antioxidants (vitamins C and E, glutathione, selenium). Under certain conditions, however, ROS production during cellular metabolism also stimulated by external agents may exceed the natural ability of cells to eliminate them from the organism. The disturbed balance leads to the state known as oxidative stress inducing damage of DNA, proteins, and lipids. An inefficient repair mechanism may finally trigger the process of neoplastic transformation or cell death. Reactive oxygen species are also an integral part of signal transduction essential for intercellular communication. The balance between pro- and antioxidative processes determines normal cellular metabolism manifested by genes activation and/or proteins expression in response to exo- and endogenous stimuli.
authors.affiliation: Department of Toxicology and Carcinogenesis, Nofer Institute of Occupational Medicine, Lódź, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Stańczyk
authors.forename: Jolanta
authors.initials: J
authors.lastname: Gromadzińska
authors.forename: Wojciech
authors.initials: W
authors.lastname: Wasowicz
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002477:Cells / Q000378:metabolism*; D006801:Humans; D017382:Reactive Oxygen Species; D015398:Signal Transduction
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species