Genistein and Daidzein

YAMAGUCHI M and suGiMOTO E (2000) Stimulatory effect of genistein and daidzein on protein synthesis in osteoblastic MC3T3-E1 cells Activation of aminoacyl-tRNA synthetase. Mol Cell Biochem 214, 97-102. 

Recently, some of the specific faecal bacteria involved in the metabolism of dietary isoflavonoids were isolated (Hur et al., 2000). They have been shown to selectively convert genistin and daidzin to their respective aglycones. One of the isolated bacteria, under anoxic conditions, was further shown to metabolise genistein and daidzein to their respective dihydroxy-genistein and dihydroxy-daidzein. In the case of lignans, enterodiol and enterolactone were shown to be excreted in vivo only in rats harbouring a gut microflora (Rowland et al, 1999). 

In addition to the effects on blood lipids, it has been suggested that soy consumption has a beneficial action on arterial function and improves antioxidant status (Lichtenstein, 1998 and refs therein). Genistein and daidzein were shown to have antioxidant properties in vitro (Kerry and Abbey, 1998), to enhance endothelium-dependent vasodilation and to reduce the development of atherosclerosis in monkeys (Honore et al, 1997 Wagner et al, 1997). 

Isoflavones have been implicated in goiter induction. Soybean extracts inhibit reactions catalyzed by thyroid peroxidase (TPO), essential to the synthesis of thyroid hormones (Divi et al., 1997). Genistein and daidzein (at about 1-10 p,M of IC50) may act as alternative substrates for tyrosine iodination (Divi et al., 1997). Furthermore, genistein and daidzein have also been shown to cause the irreversible inactivation of TPO in the presence of hydrogen peroxide. Genistein also inhibits thyroxine synthesis in the presence of iodinated... 

An inverse correlation between thyroid cancer risk and phytoestrogens was recently proposed as a result of a multi-ethnic population-based case control study conducted in the San Francisco Bay Area (Hom-Ross et al., 2002). In this study, dietary habits and phytoestrogen consumption were assessed by a food-frequency questionnaire and by a nutrient database. The outcome of the study was that soy-based foods and alfalfa sprouts were associated with a reduction of thyroid cancer risk, whereas a Western diet did not influence cancer risk. No difference was observed between American and Asian women or between pre- and postmenopausal women. Furthermore, among the few compounds examined, the isoflavones genistein and daidzein and the lignan secoisolariciresinol were the phytoestrogens most frequently associated with risk reduction (Horn-Ross et al., 2002). 

YU o, JUNG w, SHI J, CROES R A, FADER G M, MCGONIGLE B and ODELL J T (2000) Production of the isoflavones genistein and daidzein in non-legume dicot and monocot tissues. Plant Physiol. 124 (2) 781-94. 

BARNES, K.A., SMITH, R.A., WILLIAMS, K., DAMANT, A.P., SHEPHERD, MJ.A., Microbore high performance liquid chromatography/electrospray ionization mass spectrometry method for the determination of the phytoestrogens genistein and daidzein in comminuted baby foods and soya flour, Rapid Comm. Mass Spectrom., 1998,12,130-138. 

Doerge D.R., Churchwell M.I., and Delclos K.B., 2000. Online sample preparation using restricted-access media in the analysis of the soy isoflavones, genistein and daidzein, in rat serum using liquid chromatography electrospray mass spectrometry. Rapid Commun Mass Spectrom 14 673. 

Satterfield, M., Black, D.M., and Brodbelt, J.S., Detection of the isoflavone aglycones genistein and daidzein in urine using solid-phase microextraction-high-performance liquid chromatography-electrospray ionization mass spectrometry, J. Chromatogr. B, 759, 33, 2001. 

Schoefer, L., Mohan, R., Braune, A., Birringer, M., and Blaut, M., Anaerobic C-ring cleavage of genistein and daidzein by Eubacterium ramulus, FEMS Microbiol Lett., 208, 197, 2002. 

Isoflavonoids include the isoflavones genistein and daidzein, which occur mainly as the glycosides genistin and daidzin (see Figure 7.2), respectively, in soybeans and consequently in a wide range of soy-derived foods and to a lesser extent in other legumes. Traditional... 

FIGURE 7.2 Chemical structures of the main soy (genistein and daidzein) and red clover (biochanin A and formononetin) isoflavonoids (aglycones and glucosides). 

Fanti P, Sawaya PB, Custer LJ, Franke AA. 1999. Serum levels and metabolic clearance of the isoflavones genistein and daidzein in hemodialysis patients. J Am Soc Nephrol... 

Gardner C, Chatterjee L, Morris J, Franke AA. 2008. Effects of isoflavone supplements versus soy foods on blood concentrations of genistein and daidzein. J Nutr Biochem. 

Mishra SK, Abbot SE, Choudhury Z, Cheng M, Khatab N, Maycock NJ, Zavery A, Aaronson PI. 2000. Endothelium-dependent relaxation of rat aorta and main pulmonary artery by the phytoestrogens genistein and daidzein. Cardiovasc Res 46 539-546. 

Gercel-Taylor C, Feitelson AK, Taylor DD. 2004. Inhibitory effect of genistein and daidzein on ovarian cancer cell growth. Anticancer Res 24 795-800. 

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