An evaluation of the antioxidant and potential pro-oxidant properties of food additives and of trolox C, vitamin E and probucol.
The food additives propyl gallate and vanillin inhibited iron ion-dependent lipid peroxidation in rat-liver microsomes, but stimulated formation of a deoxyribose degrading species, probably hydroxyl radical, from ferric-EDTA and hydrogen peroxide. Propyl gallate accelerated DNA damage by the anti-tumour antibiotic bleomycin, although vanillin did not. The water-soluble vitamin E analogue Trolox C also stimulated bleomycin-dependent DNA damage, but not hydroxyl radical generation from ferric-EDTA and H2O2. Indeed, Trolox C was found to be a powerful scavenger of hydroxyl radical (rate constant greater than 10(10) M-1s-1). Probucol did not stimulate oxidative damage in any of the systems tested, and is a powerful inhibitor of lipid peroxidation in rat liver microsomes. The ESR spectrum of the radical produced by one electron-oxidation of probucol in ethanol is described.
Department of Biochemistry, University of London King's College, United Kingdom.
O I
OI
Aruoma
P J
PJ
Evans
H
H
Kaur
L
L
Sutcliffe
B
B
Halliwell
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001547:Benzaldehydes / Q000494:pharmacology; D001578:Benzopyrans / Q000494:pharmacology*; D001761:Bleomycin / Q000494:pharmacology; D055598:Chemical Phenomena; D002621:Chemistry; D002839:Chromans / Q000494:pharmacology*; D004249:DNA Damage; D004578:Electron Spin Resonance Spectroscopy; D005503:Food Additives / Q000494:pharmacology*; D005609:Free Radicals; D007501:Iron / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D011435:Propyl Gallate / Q000494:pharmacology; D051381:Rats; D014810:Vitamin E / Q000494:pharmacology*
D000975:Antioxidants; D001547:Benzaldehydes; D001578:Benzopyrans; D002839:Chromans; D005503:Food Additives; D005609:Free Radicals; D001761:Bleomycin; D014810:Vitamin E; D011435:Propyl Gallate; C100058:vanillin; D007501:Iron; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid