The antioxidant action of synthetic oestrogens involves decreased membrane fluidity: relevance to their potential use as anticancer and cardioprotective agents compared to tamoxifen?
The synthetic oestrogens diethylstilboestrol, hexoestrol and 17 alpha-ethynyloestradiol are known to be good antioxidants, and we now report that they decrease membrane fluidity, in ox-brain phospholipid liposomes. The order of effectiveness was diethylstilboestrol > hexoestrol > 17 alpha-ethynyloestradiol and a good positive correlation was demonstrated between decreased membrane fluidity and antioxidant ability (measured as inhibition of liposomal lipid peroxidation: correlation coefficient, r = 0.99). This ability of diethylstilboestrol, hexoestrol and 17 alpha-ethynyloestradiol to decrease membrane fluidity is suggested, therefore, to be the mechanism of their antioxidant action. The membrane-modulating antioxidant action of these synthetic oestrogens is compared to that of tamoxifen and their potential use as anticancer and cardioprotective agents is discussed.
Wiseman
H
H
Pharmacology Group, King's College, University of London, UK.
Quinn
P
P
D000970:Antineoplastic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D002316:Cardiotonic Agents / Q000494:pharmacology*; D004161:Diphenylhexatriene; D045166:Estradiol Congeners / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008081:Liposomes; D008560:Membrane Fluidity / Q000187:drug effects*; D015394:Molecular Structure; D013629:Tamoxifen / Q000494:pharmacology*
D000970:Antineoplastic Agents; D000975:Antioxidants; D002316:Cardiotonic Agents; D045166:Estradiol Congeners; D008081:Liposomes; D013629:Tamoxifen; D004161:Diphenylhexatriene