Daidzein, soy isoflavone

Atkinson C, Frankenfeld CL, Lampe JW. 2005. Gut bacterial metabolism of the soy isoflavone daidzein Exploring the relevance to human health. Exp Biol Med (May-wood) 230 155-170. 

Heinonen SM, Hoikkala A, Wahala K, Adlercreutz H. 2003. Metabolism of the soy isoflavones daidzein, genistein and glycitein in human subjects. Identification of new metabolites having an intact isoflavonoid skeleton. J Steroid Biochem Mol Biol 87 285-299. 

Kulling SE, Honig DM, Metzler M. 2001. Oxidative metabolism of the soy isoflavones daidzein and genistein in humans in vitro and in vivo. J Agric Food Chem 49 3024-3033. 

Structural similarity of the isoflavones to estrogen has been responsible for claims that they are natural alternatives to hormone replacement therapy (HRT). Soy isoflavones are not usually present in humans, unless caused by acute or chronic administration of soy products in the diet. If not in the diet, supplementation is required. One synthetic isoflavone, ipriflavone, has been shown to increase bone mass in postmenopausal women. The soy isoflavone daidzein makes up 10%o of the metabolites of ipriflavone, and it appears to be one of the metabolites that inhibit osteoclast activity in vitro. A number of studies have been reported on the effects of soy protein and genistein on bone density in rats, and it appears that it is the isoflavones that are responsible for the beneficial effects. Positive data from studies with cultured bone cells support a... 

Figure 38.1 Formulas of flavone, Isoflavone, and major soy Isoflavones daidzein and genistein.

KING R A and BURSILL D B (1998) Plasma and urinary kinetics of the isoflavones daidzein and genistein after a single soy meal in humans. Am J Clin Nutr. 67 (5) 867-72. 

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. 

Interindividual variation in ability to metabolize daidzein to equol (more estrogenic and a more potent antioxidant than daidzein) could thus influence the potential health protective effects of soy isoflavones. The extent of gut microflora metabolism in humans is variable, approximately 35% of a Western population can produce equol. ... 

Liu M, Yanagihara N, Toyohira Y, Tsutsui M, Ueno S, Shinohara Y. 2007c. Dual effects of daidzein, a soy isoflavone, on catecholamine synthesis and secretion in cultured bovine adrenal medullary cells. Endocrinology 148 5348-5354. 

Isoflavones Daidzein Genistein Glycitein Soy flour, soybeans boiled, tofu, soy milk... 

Relatively high conformation to acceptable standards was found for coenzyme QIO (of Japanese origin), but poor conformation was found with lycopene. Nurmi et al. found wide variations in 15 soy isoflavone products examined. In their report, individual isoflavone levels were not claimed, but levels of three individual compounds, daidzein, genistein, and glycitein, fluctuated... 

High-throughput quantitation of the soy isoflavones genistein, daidzein, and equol in blood from human and animal studies was developed by Twaddle et al. [74] using positive-ion LC-ESI-MS in SIM or SRM mode. Samples were processed in 96-well plate format protein precipitation, enzymatic deconjugation by H. pomatia... 

Although the regulation of the sex hormone receptors at the transcriptional level may not be considered as a hormone-like activity, it is one of the ways to control the hormonal signal. Thus, it has been reported that genistein, at concentrations of 500 pg/g body weight, decreased ERa mRNA expression [62], In a similar way, it has been described that daidzein can decrease ER0 mRNA levels in the hypothalamus of newborn piglets [63], On the other hand, some authors find that soy isoflavones increase nerve growth factor mRNA and brain derived neurotrophic factor mRNA in rats [64, 65],... 

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