Daidzein bioavailability

King, R.A., Daidzein conjugates are more bioavailable than genistein conjugates in rats. Am. 

The metabolism and bioavailability of isoflavonoids is likely to be of crucial importance to their ability to help protect human health against disease. Many studies have been published on the metabolism and bioavailability of isoflavones in adults. The metabolism of isoflavones is of particular interest because the potency of isoflavone metabolites differs from that of the parent compounds. The daidzein metabolite equol is three times as potent as is daidzein in an endometrial tumor line. Equol is also a more potent antioxidant in vitro (see Sections 7.3.5 and 7.4.2) ° and the clinical significance of the ability to form equol has been considered in depth. ... 

Intestinal microflora plays a key role in the metabolism and bioavailibility of isoflavones [86]. After ingestion, soybean isoflavones are hydrolyzed by intestinal glucosidases, which release the aglycones, daidzein and genistein, Fig. (16). 

Xu X, Wang H-J, Murphy PA, Cook L, Hendrich S. 1994. Daidzein is a more bioavailable soymilk isoflavone than is genistein in adult women. J Nutr 124 825-832. 

Fig. 78.1 Phenolics in human nutrition A microbiological perspective. Bioavailability of dietary compounds depends on the sum of molecular mechanisms underlying liberation of the compounds from dietary matrices, absorption, distribution into body tissues via blood circulation, metabolism (in the GI tract or target tissues), and elimination from the body. The keypad shows parameters of relevance to phenolic bioavailability. The two enlarged windows illustrate the diversity of both phenolics in food and microbial functions involved in phenolic conversion, with a focus on isoflavones and hgnans. Estimates of blood concentration of daidzein, equol, and enterolignans are...

Ruefer, C.E., MOseneder, J., Bub, A., Winterhalter, P., and Kulling, S.E. 2005. Bioavailability of the soybean isoflavone daidzein in the aglycone and glucoside form. In Macromolecules and their degradation products in food-Physiological, analytical and technological aspects. T. Elund, M. Schwartz et al. (Eds). 1, 53-56. 

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