Effect of genistein against copper-induced lipid peroxidation of human high density lipoproteins (HDL).
Several studies have demonstrated that the isoflavone genistein exerts a protective effect against lipid peroxidation of low density lipoproteins (LDL). Aim of our study was to investigate whether genistein protects high density lipoproteins (HDL), isolated from normolipemic subjects, against Cu(++)-induced lipid peroxidation. Our results demonstrated that genistein exerts an inhibitory effect against Cu(++)-induced lipid peroxidation of HDL, as shown by the lower increase in the levels of conjugated dienes in lipoproteins oxidized after preincubation with different concentrations of genistein (0.5-2.5microM). Moreover the analysis of fluorescence emission spectra of tryptophan (Trp) and Laurdan (6-dodecanoyl-2-dimethyl-aminonaphthalene) demonstrated that genistein prevents the alterations of apoprotein structure and physico-chemical properties, associated with Cu(++)-triggered lipid peroxidation of lipoproteins. The protective effect exerted by genistein against oxidative damage of lipoproteins was realized at concentrations similar to those observed in plasma of human subjects consuming a traditional soy diet or receiving a soy supplement. Therefore, we suggested that antioxidant activity exerted by genistein against lipid peroxidation of HDL in vitro could be of physiological relevance.
Ferretti
G
G
Institute of Biochemistry, Faculty of Medicine, University of Ancona, Via Ranieri, I-60131, Ancona, Italy.
Bacchetti
T
T
Menanno
F
F
Curatola
G
G
D015081:2-Naphthylamine / Q000031:analogs & derivatives* / Q000032:analysis; D000975:Antioxidants / Q000494:pharmacology*; D001059:Apoproteins / Q000737:chemistry; D003300:Copper / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D005453:Fluorescence; D019833:Genistein / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007848:Laurates / Q000032:analysis; D015227:Lipid Peroxidation / Q000187:drug effects*; D008075:Lipoproteins, HDL / Q000378:metabolism*; D045730:Soy Foods; D014364:Tryptophan / Q000032:analysis
D000975:Antioxidants; D001059:Apoproteins; D007848:Laurates; D008075:Lipoproteins, HDL; D003300:Copper; D014364:Tryptophan; D015081:2-Naphthylamine; D019833:Genistein; C065580:laurdan