Carcinogenic antioxidants. Diethylstilboestrol, hexoestrol and 17 alpha-ethynyloestradiol.
The synthetic oestrogens diethylstilboestrol, hexoestrol and 17 alpha-ethynyloestradiol are known to be carcinogenic, yet they all exert antioxidant properties in vitro in that they are good inhibitors of iron ion-dependent lipid peroxidation. In rat liver microsomes incubated with Fe(III)-ascorbate or Fe(III)-ADP/NADPH and also in ox-brain phospholipid liposomes incubated with Fe(III)-ascorbate; the overall order of effectiveness of the compounds tested as inhibitors of lipid peroxidation was diethylstilboestrol > hexoestrol > 17 alpha-ethynyloestradiol > 4-hydroxytamoxifen > 17 beta-oestradiol > tamoxifen. Compounds acting as antioxidants towards lipids may also exert pro-oxidant effects towards other molecules such as DNA and thus must never be assumed to be safe for human use.
Wiseman
H
H
Pharmacology Group, King's College, University of London, UK.
Halliwell
B
B
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002273:Carcinogens / Q000494:pharmacology*; D004054:Diethylstilbestrol / Q000494:pharmacology*; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D006589:Hexestrol / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D013629:Tamoxifen / Q000031:analogs & derivatives / Q000494:pharmacology
D000975:Antioxidants; D002273:Carcinogens; D013629:Tamoxifen; D006589:Hexestrol; C016601:afimoxifene; D004997:Ethinyl Estradiol; D004054:Diethylstilbestrol