Metabolism of Estrogenic Isoflavones in Domestic Animals

Lundh, Torbjörn

doi:10.3181/00379727-208-43828

Cited by 108 publications

(123 citation statements)

References 9 publications

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“…The very high concentration of equol in milk from especially cows grazing red clover was expected, since red clover has a high concentration of formononetin (0.8 to 11 mg/g DM) but also biochanin A (0.8 to 5 mg/g DM) depending on the part (flower, stem or leaves) and maturity of the plant, cultivar and environment (Sivesind and Seguin, 2005;Booth et al, 2006). Formononetin is metabolized by microbes in the rumen via daidzein to equol which is the major isoflavone absorbed to the blood circulation after feeding red clover/grass silage, whereas biochanin A is demethylated to genistein to form mainly p-ethyl phenol (Lundh, 1995). Unfortunately, the concentration of daidzein in herbage, and genistein in herbage and milk, could not been analysed in this experiment as previously described.…”

Section: Discussionmentioning

confidence: 99%

Phyto-oestrogens in herbage and milk from cows grazing white clover, red clover, lucerne or chicory-rich pastures

Andersen

Nielsen

Purup³

et al. 2009

Animal

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A grazing experiment was carried out to study the concentration of phyto-oestrogens in herbage for cattle and in milk during two periods (May and June). Forty-eight Danish Holstein cows were divided into four groups with four treatment diets; white clover, red clover, lucerne and chicory-rich pastures. Each experimental period lasted 15 days. Herbage samples from the first day and individual milk samples from the last day of the experimental period were analysed for phyto-oestrogens using LC-MS technique. The total concentration of phyto-oestrogens was 21 399 mg/kg dry matter (DM) for red clover and 238 to 466 mg/kg DM for the other three herbages mainly due to a much higher concentration of biochanin A, formononetin and glycitein in red clover. In the milk, the total concentration of phyto-oestrogens was 253 to 397 mg/l for red clover milk and 56 to 91 mg/l in the milk from the other three treatments. This was especially due to a higher concentration of equol, daidzein and formononetin in the red clover milk. The concentration of biochanin A was significantly higher in milk from the red clover treatment in May while no differences were observed in June. Enterodiol was similar across treatments while the concentration of enterolactone was significantly lower for red clover milk compared with the other treatments. Of the tested pastures, red clover appears to have the highest concentration and to be the best source of phyto-oestrogens, especially equol, in bovine milk.

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Section: Discussionmentioning

confidence: 99%

Phyto-oestrogens in herbage and milk from cows grazing white clover, red clover, lucerne or chicory-rich pastures

Andersen

Nielsen

Purup³

et al. 2009

Animal

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“…Higher net production of SECO for GH than GS incubated with ruminal microbiota may result from the higher initial concentration of SDG in GH than GS [32AE0 vs 9AE2 nmol (100 mg )1 )] as hydrolysation of SDG is known to produce SECO under the action of intestinal glycosidases from microbial origin (Saarinen et al 2002). Rumen micro-organisms readily hydrolyse isoflavones present in the glycoside form (Lundh 1995) and SDG is the glycoside form of SECO (Johnsson et al 2000). Therefore, higher concentration of SDG in GH than GS is the likely cause for the increased concentration of SECO with GH.…”

Section: Discussionmentioning

confidence: 99%

In vitrometabolism of flax lignans by ruminal and faecal microbiota of dairy cows

Côrtes

Gagnon

Benchaar

et al. 2008

Journal of Applied Microbiology

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Aims: To determine the in vitro conversion of plant lignans from two flax products (hull and seed) into the mammalian lignans, enterolactone and enterodiol, by bovine ruminal and faecal microbiota. Methods and Results: Flax seeds and hulls were incubated in vitro over a 96‐h time course with ruminal or faecal inoculum. Plant lignans in flax seeds and hulls averaged 9·2 and 32·0 nmol mg−1, respectively. The highest net production of enterodiol at 72 and 96 h of incubation was obtained with flax hulls incubated with faecal microbiota. There was no difference in net production of enterodiol between flax products within the first 24 h of incubation. In general, net production of enterolactone over the 96‐h time course was significantly higher for flax products incubated with ruminal than with faecal microbiota. Net production of enterolactone at 72 and 96 h of incubation was greater for flax hulls than flax seeds. Conclusions: Results of the present experiment suggest that, of the metabolites studied, the main mammalian lignan metabolite produced from flax hulls and seeds by ruminal microbiota is enterolactone while faecal microbiota leads mainly to the net production of enterodiol. Significance and Impact of the Study: This research will improve the understanding of the metabolic pathway of mammalian lignans in dairy cows, in order to enable targeted manipulation of their quantities in milk.

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“…Moreover, the microbiological metabolism of phytoestrogens in the intestines of geese is not well known yet. For example, in ruminants (Lund, 1995) genistein and daidzein may be transformed by microorganisms in the rumen to para-ethyl phenol and equol, respectively. These metabolites demonstrate weaker biological activity than their substrates.…”

Section: Discussionmentioning

confidence: 99%

Effects of dietary meals containing different levels of phytoestrogens on reproductive function in Bilgoraj ganders

Opałka

Kugla-Owczarska

Kamińska

et al. 2008

Acta Veterinaria Hungarica

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The aim of this study was to investigate how long-term feeding of ganders with diets containing different levels of phytoestrogens affects the morphometry of testes, plasma steroid levels, sperm parameters and reproductive performance. Male Bilgoraj geese were fed diets containing grass meal (with low phytoestrogen levels) and those containing alfalfa meal and soybean meal (with higher levels of phytoestrogens). Testes were obtained from ganders at the peak of mating and the ongoing laying period as well as at the beginning of photorefractoriness. The morphometric parameters were measured in frozen testicular sections. Blood was collected monthly from December to June, and plasma testosterone, androstenedione and corticosterone concentrations were determined. During the mating season, semen was collected and its quantity and quality were investigated. In the flocks (ganders with geese) reproductive output was noted. Seasonal changes were observed in the morphology of testes and in plasma testosterone, androstenedione and corticosterone concentrations in ganders. The feeding of ganders with dietary meals containing higher levels of phytoestrogens did not affect the plasma steroid contents or the majority of the morphometric parameters of testes, except for the height of the seminiferous epithelium, which was lowered. Moreover, diets with higher levels of phytoestrogens decreased the volume of ejaculates and the percentage of normal spermatozoa. However, these changes were not reflected in the fertilisation rates.

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Metabolism of Estrogenic Isoflavones in Domestic Animals

Cited by 108 publications

References 9 publications

Phyto-oestrogens in herbage and milk from cows grazing white clover, red clover, lucerne or chicory-rich pastures

Phyto-oestrogens in herbage and milk from cows grazing white clover, red clover, lucerne or chicory-rich pastures

In vitrometabolism of flax lignans by ruminal and faecal microbiota of dairy cows

Effects of dietary meals containing different levels of phytoestrogens on reproductive function in Bilgoraj ganders

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