title: Dietary alpha-tocopherol prevents dehydroepiandrosterone-induced lipid peroxidation in rat liver microsomes and mitochondria.
abstract: Dehydroepiandrosterone (DHEA), an adrenal steroid, causes lipid peroxidation in rat liver microsomes and mitochondria and induces hepatocarcinogenesis. It was investigated whether alpha-tocopherol, a naturally occurring free radical chain terminator, could decrease lipid peroxidation. When DHEA-free diet supplemented with increasing concentrations of alpha-tocopherol (25, 50, 100, 200, 400 and 1000 mg/kg diet) was fed to rats for 7 days, a marked lipid peroxidation (measured as thiobarbituric acid reactive substances formation) was observed at concentrations 25 and 50 mg/kg in liver microsomes and mitochondria isolated from these animals. Lipid peroxidation was significantly reduced at concentrations > or = 100 mg/kg. When DHEA (500 mg/kg diet) was fed to rats simultaneously with increasing concentrations of alpha-tocopherol, strong lipid peroxidation was observed at alpha-tocopherol concentrations < or = 200 mg/kg diet. However, microsomes and mitochondria isolated from livers of rats fed alpha-tocopherol at doses of 400 and 1000 mg/kg diet produced only negligible amounts of thiobarbituric acid reactive substances. The data show that high concentrations of alpha-tocopherol in the diet decrease DHEA-induced microsomal and mitochondrial lipid peroxidation. Our results support the concept that alpha-tocopherol can protect against DHEA-induced lipid peroxidation and consequently against steroid-induced liver cell damage and, perhaps, also tumour development.
authors.affiliation: Department of Biochemistry, Medical University of Gdansk, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Swierczynski
authors.forename: Z
authors.initials: Z
authors.lastname: Kochan
authors.forename: D
authors.initials: D
authors.lastname: Mayer
mesh_terms: D000818:Animals; D003687:Dehydroepiandrosterone / Q000037:antagonists & inhibitors / Q000633:toxicity*; D005527:Food, Fortified; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects*; D008930:Mitochondria, Liver / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014810:Vitamin E / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D014810:Vitamin E; D003687:Dehydroepiandrosterone