Antioxidant activity of phytoestrogen type isoflavones in biomimetic environments

Abstract

The work aims to simulate in vitro the antioxidant activity of four phytoestrogen type isoflavones, whose effects are closer to those of estradiol (daidzein, formononetin, genistein, biochanin A) in biomimetic environments (in lecithin lipidic bi-layers and on silver nanoparticles), using the chemiluminescent system luminol–hydrogen peroxide, in phosphate buffer, pH 7.4. The contribution of a carrier protein, human serum albumin (HSA), to the antioxidant activity of these isoflavones has also been investigated. The rate of the fluorescence quenching of HSA by isoflavone as well as the binding constant of isoflavone to HSA, in both lecithin lipidic bi-layers and on silver nanoparticles, has also been investigated by fluorescence spectroscopy. The results are discussed with relevance to the oxidative stress process.