caa a22 4500 475792858 CHVBK 20180406123715.0 cr unu---uuuuu 170329e20001201xx s 000 0 eng 10.1023/A:1011167023695 doi (NATIONALLICENCE)springer-10.1023/A:1011167023695 A Comparative Study of the Effects of Cholesterol, Beta-Sitosterol, Beta-Sitosterol Glucoside, Dehydro-epiandrosterone Sulphate and Melatonin on In Vitro Lipid Peroxidation [Elektronische Daten] [S.J. van Rensburg, W.M.U. Daniels, J.M. van Zyl, J.J.F. Taljaard] The free radical scavenging abilities of the structurally related steroids beta-sitosterol, beta-sitosterol glucoside (plant sterols and sterolins), cholesterol, and dehydroepiandrosterone sulphate (DHEAS) were compared with melatonin (an efficient free radical scavenger) in an in vitro system which measures lipid peroxidation of platelet membranes in the presence of iron (Fe2+). Lipid peroxidation is a process whereby cellular membranes are damaged due to the oxidative deterioration of polyunsaturated lipids, which may lead to cell death and disease in living organisms. Substances such as vitamin E protect cellular membranes against oxidative damage due to their chemical structures. The steroids cholesterol, beta-sitosterol, beta-sitosterol glucoside and dehydroepiandrosterone (DHEA) are structurally related to each other. During aging, serum concentrations of DHEA, DHEAS and melatonin decrease, while the concentration of cholesterol tends to increase. The aim of the present study was to compare the role these substances play in lipid peroxidation over a wide concentration range. At concentrations lower than the free iron in the reaction mixture, all the steroids investigated decreased lipid peroxidation. At higher concentrations, cholesterol and beta-sitosterol increased lipid peroxidation, while DHEAS and melatonin continued to decrease lipid peroxidation. Plenum Publishing Corporation, 2000 Lipid peroxidation nationallicence cholesterol nationallicence melatonin nationallicence DHEAS nationallicence plant sterols nationallicence aging nationallicence van Rensburg S.J. Department of Chemical Pathology, Tygerberg Hospital and University of Stellenbosch Medical School, South Africa aut Daniels W.M.U. Department of Medical Physiology and Biochemistry, University of Stellenbosch Medical School, South Africa aut van Zyl J.M. Department of Pharmacology, University of Stellenbosch Medical School, South Africa aut Taljaard J.J.F. Department of Chemical Pathology, Tygerberg Hospital and University of Stellenbosch Medical School, South Africa aut Metabolic Brain Disease Kluwer Academic Publishers-Plenum Publishers 15/4(2000-12-01), 257-265 0885-7490 15:4<257 2000 15 11011 https://doi.org/10.1023/A:1011167023695 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1011167023695 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- van Rensburg S.J. Department of Chemical Pathology, Tygerberg Hospital and University of Stellenbosch Medical School, South Africa aut NATIONALLICENCE 700 1- Daniels W.M.U. Department of Medical Physiology and Biochemistry, University of Stellenbosch Medical School, South Africa aut NATIONALLICENCE 700 1- van Zyl J.M. Department of Pharmacology, University of Stellenbosch Medical School, South Africa aut NATIONALLICENCE 700 1- Taljaard J.J.F. Department of Chemical Pathology, Tygerberg Hospital and University of Stellenbosch Medical School, South Africa aut NATIONALLICENCE 773 0- Metabolic Brain Disease Kluwer Academic Publishers-Plenum Publishers 15/4(2000-12-01), 257-265 0885-7490 15:4<257 2000 15 11011 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer