Isoflavonoids metabolism

PAIVA, N.L., OOMMEN, A, HARRISON, M.J, DIXON, R.A., Regulation of isoflavonoid metabolism in alfalfa, Plant Cell, Tissue and Organ Cult., 1994, 38, 213-220. 

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). 

MORTON M S, MATOS-FERREIRA A, ABRANCHES-MONTEIRO L, CORREIA R, BLACKLOCK N, CHAN P S, CHENG 0, LLOYD s, CHIEH-PING w and GRIFFITHS K (1997) Measurement and metabolism of isoflavonoids and lignans in the human male. Cancer Lett. 114 (1-2) 145-51. 

DIXON, R.A., STEELE, C.L., Flavonoids and isoflavonoids - a gold mine for metabolic engineering, Trends Plant Sci., 1999, 4, 394-400. 

Isoflavonoid has been used as dietary biomarkers [103,104], It has been further established that isoflavonoids influence receptor expression [105] and induce immune changes [106,107], The individual variation in metabolism of isoflavones has also been extansively studied [108,109], It has been further demonstrated that flavonoids show antiinflammatory effects on adjuvant arthritis [110], and protect mice from two types of lethal shock caused by endotoxin [111],... 

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. ... 

Hodgson JM, Croft KD, Puddey IB, Mori TA, Beilin LJ. Soybean isoflavonoids and their metabolic products inhibit in vitro lipoprotein oxidation in serum. J. Nutr. Biochem. 7, 664-669, 1996. 

Wiseman H, Casey K, Bowey EA et al. Influence of 10 wk of soy consumption on plasma concentrations and excretion of isoflavonoids and on gut microfiora metabolism in healthy adults. Am. J. Clin. Nutr. 80, 692-699, 2004. 

Dixon RA, Steele CL. 1999. Flavonoids and isoflavonoids—a goldmine for metabolic engineering. Trends Plant Sci 4 394 -00. 

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. 

Deavours BE, Dixon RA. 2005. Metabolic engineering of isoflavonoid biosynthesis in alfalfa. Plant Physiol 138 2245-2259. 

Dixon RA, Choundhary AD, Dalkin K, Edwards R, Fahrendorf T, Gowni G, Harrison MJ, Lamb CJ, Loake GJ, Maxwell CA, Orr J, Paiva NL. 1992. Molecular biology of stress-induced phenylpropanoid and isoflavonoid biosynthesis in alfalfa. In Stafford HA, Ibrahim RK, Eds. Phenolic Metabolism in Plants. New York Plenum, pp. 91-138. 

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