title: Benzene metabolites enhance reactive oxygen species generation in HL60 human leukemia cells.
abstract: Benzene is myelotoxic and leukemogenic in humans. The mechanisms leading to these effects, however have not been fully elucidated. One of the underlying mechanisms is believed to be the oxidative damage caused by its metabolites. A comparative study was undertaken to examine the relationships between reactive oxygen species (ROS) production, lipid peroxidation and subsequent cytotoxicity induced by five major benzene metabolites. The generation of ROS by benzene metabolites was demonstrated by the significant and dose-dependent increase of intracellular ROS formation in HL60 human promyelocytic leukemia cells in vitro. 1,4-Benzoquinone (BQ) was found to be the most potent metabolite in induction of ROS formation, followed by 1,2,4-benzenetriol (BT) and to a lesser extent, phenol (PH) and trans, trans-muconaldehyde (MD). No significant effect was observed when the cells were treated with trans, trans-muconic acid (MA). The enhancement of ROS production by BQ was effectively inhibited by the addition of catalase, deferoxamine (DFO) and dimethyl sulfoxide (DMSO), but unchanged by superoxide dismutase (SOD), suggest that hydrogen peroxide (H2O2) and hydroxyl radicals (OH) are the two major forms of ROS involved. The results also demonstrate that the ability of benzene metabolites in enhancing ROS generation is closely correlated to their capacity in causing lipid peroxidation and subsequent cytotoxicity. These findings together with earlier parallel observations on DNA damage suggest that ROS play an important role in the mechanism of carcinogenesis induced by benzene metabolites.
authors: Department of Community, Occupational and Family Medicine, National University of Singapore, Kent Ridge, Singapore.
authors: Y
authors: Y
authors: Shen
authors: H M
authors: HM
authors: Shen
authors: C Y
authors: CY
authors: Shi
authors: C N
authors: CN
authors: Ong
mesh_terms: D000447:Aldehydes / Q000378:metabolism / Q000633:toxicity; D001555:Benzene Derivatives / Q000378:metabolism / Q000633:toxicity*; D016227:Benzoquinones / Q000378:metabolism / Q000633:toxicity; D002273:Carcinogens / Q000378:metabolism / Q000633:toxicity*; D002374:Catalase / Q000494:pharmacology; D003676:Deferoxamine / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000494:pharmacology; D018922:HL-60 Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D006873:Hydroquinones / Q000378:metabolism / Q000633:toxicity; D017665:Hydroxyl Radical / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D010636:Phenols / Q000378:metabolism / Q000633:toxicity; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013011:Sorbic Acid / Q000031:analogs & derivatives / Q000378:metabolism / Q000633:toxicity; D013329:Structure-Activity Relationship; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D000447:Aldehydes; D001555:Benzene Derivatives; D016227:Benzoquinones; D002273:Carcinogens; D016166:Free Radical Scavengers; D006873:Hydroquinones; D010636:Phenols; D017382:Reactive Oxygen Species; C013038:hydroxyhydroquinone; C034476:muconaldehyde; D017665:Hydroxyl Radical; C005939:muconic acid; C004532:quinone; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase; D003676:Deferoxamine; D013011:Sorbic Acid; D004121:Dimethyl Sulfoxide