Soy isoflavone supplementation elevates erythrocyte superoxide dismutase, but not plasma ceruloplasmin in postmenopausal breast cancer survivors

Abstract

Soy isoflavone antioxidant effects may help prevent breast cancer re-occurrence, but isoflavone estrogen-like actions may increase breast cancer risk. These isoflavone actions can be reflected by effects on two copper enzymes activities, superoxide dismutase 1 (SOD 1), which has antioxidant function relevant to breast cancer prevention, and ceruloplasmin, which has its synthesis up-regulated by estrogen, and for which high values are associated with high breast cancer risk. A soy isoflavone-rich concentrate supplement was examined for effects on these two copper enzyme activities in post-menopausal breast cancer survivors (n = 7) in a crossover design with a placebo (24 days on supplement or placebo; 14 day wash out). The soy concentrate, but not the placebo, increased erythrocyte SOD 1 activities, but not ceruloplasmin activities or protein. The effect on superoxide dismutase activities was not likely due to increased copper intake since analysis of the soy extract showed little copper. The effect on superoxide dismutase was not accompanied by a change in urinary contents of 8-deoxyhydroxyguanosine, a DNA oxidant product, though perhaps this would change with a longer intervention. In summary, in regard to two copper enzyme activities, an isoflavone-rich soy concentrate showed an antioxidant effect considered relevant to breast cancer, but not an effect associated with estrogenic activity and increased breast cancer risk.

Acute reduction of serum 8-iso-PGF2-alpha and advanced oxidation protein products in vivo by a polyphenol-rich beverage; a pilot clinical study with phytochemical and in vitro antioxidant characterization

“…The latter lack of effect occurred even if isoflavones were added well in excess of what oral intake could produce in serum samples. Similarly, a 4-week intake of an isoflavone concentrate can raise erythrocyte contents of the antioxidant enzyme superoxide dismutase 1, but this effect would not be expected to occur immediately after a single intake of isoflavones [10]. …”

Dietary administration of soybean isoflavones enhances the immunity of white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus

“…SI have been shown to exhibit antioxidant effects both in vitro and in vivo . Disilvestro et al. (2005) reported that SI given in capsules elevate erythrocyte superoxide dismutase in human.…”

Nutraceuticals and Nutraceutical Supplementation Criteria in Cancer: A Literature Survey

“…The biomarker of cancer such as metalloproteinases [109], vitamin D hydroxylase [110], interleukins [111], omega-3 fatty acids [112], induced neutropenia [113], DNA adducts [114], DNA methylases [115], polymorphism [116], superoxide dismutase [117] have been discovered as potent indicators of nutraceutical chemopreventive mechanism. Still the action of phytochemicals and role of bacteria is not understood [118,119].…”