Antioxidants phytoestrogens

Phytoeslerogens have gained much interest in recent years because of their potential protective effects against many diseases and conditions including several forms of cancer, cardiovascular and neurodegenerative diseases, osteoporosis, and menopausal symptoms [59-68]. They impart antioxidant, phytoestrogenic, antiproliferative, and enzyme modulating activities within the human... 

The antioxidant properties of phytoestrogens have been studied in vitro and it has been suggested that these may be related to the chemical structure... 

Mitchell JH, Gardner PT, Mcphail DB et al. Antioxidant efficacy of phytoestrogens in chemical and biological model systems. Arch. Biochem. Biophys. 360, 142-148, 1998. 

Wiseman H, O Reilly J, Lim P et al. Antioxidant properties of the isofiavone phytoestrogen functional ingredient in soy products. In Functional Foods, the Consumer, the Products and the Evidence (M Sadler, M Saltmarsh, editors). Royal Society of Chemistry, Cambridge, pp. 80-86, 1998. 

Phytoestrogens at very low concentrations act as Antioxidants because they Up-regulate Antioxidant Enzyme Gene Expression... 

Figure 11.1 Mechanism of the up-regulation of antioxidant genes by phytoestrogens.

Hwang J, Wang J, Morazzoni P, Hodis HN, Sevanian A. 2003. The phytoestrogen equol increases nitric oxide availability by inhibiting superoxide production An antioxidant mechanism for cell-mediated LDL modification. Free Radic Biol Med 34 1271-1282. 

Siow RC, Li FY, Rowlands DJ, de Winter P, Mann GE. 2007. Cardiovascular targets for estrogens and phytoestrogens Transcriptional regulation of nitric oxide synthase and antioxidant defense genes. Free Radio Biol Med 42 909-925. 

Certain phytoestrogens have also been suggested to inhibit enzymes involved in estrogen biosynthesis and metabolism, as well as thyroid biosynthesis. Preliminary studies suggest they inhibit protein kinases and topoisomerases, as well as influence the cell cycle and subsequent proliferation, differentiation and apoptotic pathways. Interest in phytoestrogens, such as isoflavones, has increased since they are reported to exhibit some nonhormonal effects, such as antioxidation. 

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