title: Evidence of increased formation of products retaining strong antioxidant activity from estradiol-17beta oxidation in the presence of human plasma lipoproteins.
abstract: Estradiol-17beta (E2) exhibits potent antioxidant effects that cause continuous suppression of metal-catalyzed oxidation of low-density-lipoprotein in vitro. We sought to learn whether unidentified oxidation products retaining strong antioxidant property may be generated from E2 incubated with lipoproteins and subjected to oxidation by reactive oxygen species generators. E2 oxidation was markedly stimulated in the presence of both LDL and high-density lipoprotein. We have isolated two novel products (less polar than E2), formed when E2 was oxidized with copper sulfate and hydrogen peroxide in the presence of lipoproteins). Both compounds had molecular weights of 306 on gas chromatography/mass spectrometry. They appear to be as strong as E2 in inhibiting LDL oxidation in vitro. Because of their increased hydrophobicity, they have the potential of being associated with LDL and offer promise as agents that can limit LDL oxidation, thereby contributing to cardioprotection.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Cincinnati Medical Center, OH, USA. Ravi.Subbiah@uc.edu
authors.forename: M T Ravi
authors.initials: MT
authors.lastname: Subbiah
authors.forename: William
authors.initials: W
authors.lastname: Abplanalp
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D019327:Copper Sulfate / Q000737:chemistry; D004958:Estradiol / Q000737:chemistry* / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects*; D008074:Lipoproteins / Q000097:blood* / Q000494:pharmacology*; D008075:Lipoproteins, HDL / Q000494:pharmacology; D008077:Lipoproteins, LDL / Q000494:pharmacology; D008970:Molecular Weight; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000737:chemistry
chemical_list: D000975:Antioxidants; D008074:Lipoproteins; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D017382:Reactive Oxygen Species; D004958:Estradiol; D006861:Hydrogen Peroxide; D019327:Copper Sulfate