The excretion of lignans in rats — evidence for an intestinal bacterial source for this new group of compounds

Axelson, Magnus; Setchell, K. D. R.

doi:10.1016/0014-5793(81)80322-5

Cited by 249 publications

(112 citation statements)

References 18 publications

Supporting

Mentioning

108

Contrasting

Unclassified

Order By: Relevance

“…In both species of rodents equol, not daidzein or genistein, was the major isoflavone in serum and urine. Equol was first isolated from rat urine two decades ago, characterized by mass spectrometry (Axelson et al, 1982;Axelson and Setchell, 1981), and its origin was found to be soy meal used in the manufacture of the rodent chow . It was shown subsequently to be a specific intestinal bacterial metabolite of the soy isoflavones, daidzin and daidzein (Borriello et al, 1985;.…”

Section: Brown and Setchellmentioning

confidence: 99%

“…The methanolic extract was diluted to 80% by the addition of water and then passed through a small column bed (7 cm ϫ 0.4 cm) of the lipophilic anion exchange gel, triethylaminohydroxypropyl Sephadex LH-20, prepared in the hydroxide form in 80% methanol column (Axelson and Setchell, 1980). This gel affords separation of neutral compounds, which pass directly through the gel, from phenolics, which are retained (Axelson and Setchell, 1981). After elution of the neutral compounds with 80% methanol, the column was washed with 5 mL of chloroform/methanol (1:1 by volume), and this was discarded.…”

Section: Serum and Urine Analysismentioning

confidence: 99%

See 1 more Smart Citation

Animal Models Impacted by Phytoestrogens in Commercial Chow: Implications for Pathways Influenced by Hormones

Brown

Setchell

2001

Laboratory Investigation

273

239

View full text Add to dashboard Cite

SUMMARY:It is generally not known that most commercial rodent diets are formulated with soy protein and deliver large daily doses of isoflavones to animals throughout their lifespan, including the in utero period. Here, we demonstrate that isoflavones are bioavailable and show that commercial rodent diets universally used by animal facilities lead to very high steady-state serum isoflavone concentrations in adult rats (2613 Ϯ 873 ng/mL) and mice (2338 Ϯ 531 ng/mL), exceeding the animal's endogenous estrogen level by 30,000-to 60,000-fold. We demonstrate the maternal-fetal intrauterine transfer of isoflavones in animals fed a standard Purina 5001 soy-containing diet and show that newborn rat pups have high serum isoflavones levels (540 Ϯ 174 ng/mL) that are maintained throughout the suckling period by passage of isoflavones into maternal milk. These findings have profound implications for all animal experiments, including multigenerational studies and studies of transgenic animals, especially if biochemical or morphological end-points are influenced by the hormonal or nonhormonal properties of phytoestrogens. These compounds have the potential to modulate genotypic and phenotypic expression in general, and therefore, all investigators should be vigilant to the phytoestrogen composition of commercial rodent diets because there is a history of potent biological effects in larger animals and in humans from high circulating isoflavone concentrations. (Lab Invest 2001, 81:735-747).A lthough phytoestrogens are ubiquitous in the plant kingdom, it is soybeans and foods made with purified soy proteins that are by far the greatest contributors of isoflavones to animal and human diets (Coward et

show abstract

Section: Brown and Setchellmentioning

confidence: 99%

Section: Serum and Urine Analysismentioning

confidence: 99%

Animal Models Impacted by Phytoestrogens in Commercial Chow: Implications for Pathways Influenced by Hormones

Brown

Setchell

2001

Laboratory Investigation

273

239

View full text Add to dashboard Cite

show abstract

“…Interestingly, previous rodent studies have documented highest blood concentrations of certain dietary phytochemicals in the portal circulation [12], hence, the greatest potency of such compounds might be seen in the liver.…”

Section: Probiotics and Phytochemical Metabolism-the Role Of Gut Flormentioning

confidence: 99%

Probiotics in Human Health and Disease: A New Avenue of Understanding between Diet, Disease and Metabolic Disorders

Wilcox¹

2013

J Prob Health

View full text Add to dashboard Cite

“…[15][16][17][18] Intestinal bacteria metabolize plant lignans by processes such as deglucosylation, demethylenation, ring cleavage, demethylation, dehydroxylation and oxidation. Several human intestinal bacteria that function in these processes have been isolated and characterized.…”

Section: -7)mentioning

confidence: 99%

Human Intestinal Bacterium, Strain END-2 Is Responsible for Demethylation as Well as Lactonization during Plant Lignan Metabolism

Hattori

2010

Biological & Pharmaceutical Bulletin

View full text Add to dashboard Cite

Plant lignans and isoflavones that have estrogen-like properties, are classified as phytoestrogens based on their activities and chemical structures.1,2) Experimental and epidemiological studies have shown that phytoestrogens have potential health benefits in treating hormone-dependent diseases such as breast and prostate cancers. 3-7)Because ingested plant lignans undergo metabolic degradation, their transformation and metabolites have been extensively studied. [8][9][10][11][12][13] The mammalian lignans, enterolactone (ENL) and enterodiol (END), are of considerable interest since their isolation from the urine of humans and other animals in 1980.14) Subsequent studies have verified that the origins of mammalian lignans are plant lignans and that intestinal bacteria play a critical role in the formation of ENL and END. [15][16][17][18] Intestinal bacteria metabolize plant lignans by processes such as deglucosylation, demethylenation, ring cleavage, demethylation, dehydroxylation and oxidation. Several human intestinal bacteria that function in these processes have been isolated and characterized. 10,11,[19][20][21][22] However, ENL and END have two enantiomeric, mirror image forms. The ENL that is transformed via the anaerobic incubation of pinoresinol diglucoside (PDG) from Eucommia ulmoides OLIV. with intestinal bacteria, assumes the (Ϫ)-form.10) On the other hand, the ENL that is obtained via incubation with secoisolariciresinol diglucoside (SDG) from flaxseed, assumes the (ϩ)-form.13) We investigated which bacteria are involved in the transformation of the respective enantiomeric forms.The human intestinal bacteria, Eggerthella (Eg.) sp. SDG-2 and strain ARC-1 enantioselectively dehydroxylate dihydroxyenterolactone (DHENL) and dihydroxyenterodiol (DHEND). Moreover, the bacterial strains, strain END-2 and Ruminococcus (R.) sp. END-1, which oxidize END to ENL were isolated from human feces.24) When strain END-2 was incubated with a mixture of (ϩ)-END and (Ϫ)-END, only (ϩ)-END was oxidized to (ϩ)-ENL, and (Ϫ)-END remained unchanged (Fig. 1). Conversely, R. sp. END-1 converted only (Ϫ)-END to (Ϫ)-ENL.Here, we further describe the substrate specificity and cooperative behavior of strain END-2 with strain ARC-1 during the metabolism of plant lignans. MATERIALS AND METHODSGeneral Fecal suspensions and intestinal bacteria were incubated in an anaerobic model EAN-140 incubator (Tabai Co., Osaka, Japan). Optical rotations were measured in MeOH using a DIP-360 automatic polarimeter (Jasco Co., Tokyo, Japan). H-1 H-correlated spectroscopy, heteronuclear multiple-quantum coherence, heteronuclear multiple-bond coherence and nuclear Overhauser effect spectroscopy experiments were performed using a Varian Unity 500 ( 1 H: 500 MHz, 13 C: 125 MHz) and a Varian Gemini 300 ( 1 H: 300 MHz, 13 C: 75 MHz). Samples were separated by TLC on plates precoated with silica gel 60-F 254 (0.25 mm, Merck Co., Darmstadt, Germany), and spots were detected under UV excitation or by exposure to I 2 vapor. Samples were also separated by chrom...

show abstract

The excretion of lignans in rats — evidence for an intestinal bacterial source for this new group of compounds

Cited by 249 publications

References 18 publications

Animal Models Impacted by Phytoestrogens in Commercial Chow: Implications for Pathways Influenced by Hormones

Animal Models Impacted by Phytoestrogens in Commercial Chow: Implications for Pathways Influenced by Hormones

Probiotics in Human Health and Disease: A New Avenue of Understanding between Diet, Disease and Metabolic Disorders

Human Intestinal Bacterium, Strain END-2 Is Responsible for Demethylation as Well as Lactonization during Plant Lignan Metabolism

Contact Info

Product

Resources

About