The effect of supplementing a basal diet for dairy cows with "Soybean extract 40" (Biomedica, Prague, Czech Republic), containing 40% soybean isoflavones, on the contents of daidzein, glycitein, genistein, and equol in milk as well as fresh and mature yogurts was estimated. To determine the contents of these isoflavonoids, an efficient analytical LC-MS (TOF) technique was used. The "Soybean extract 40" used in our study contained an especially high proportion of daidzein (307gkg-1). In both milk and yogurt samples, the amounts of daidzein and its metabolite equol were significantly higher in samples obtained from cows that received the isoflavone extract-supplemented diet than from those that received the basal diet, as the precursor daidzein contributed to the increased equol concentrations. Fermentation caused significant changes in the daidzein and glycitein concentrations. With maturation, the concentrations of daidzein and equol were unaffected, while the glycitein concentration decreased significantly.

• Klíčová slova
• Bovine milk, Daidzein (PubChem CID: 5281708), Dairy products, Equol, Equol (PubChem CID: 382975), Genistein (PubChem CID: 5280961), Glycitein (PubChem CID: 5317750), Isoflavones, Phytoestrogens, Storage,
• MeSH
• chromatografie kapalinová MeSH
• equol analýza   MeSH
• Glycine max chemie   MeSH
• hmotnostní spektrometrie MeSH
• isoflavony analýza   MeSH
• jogurt analýza   MeSH
• mléko chemie   MeSH
• skot MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• daidzein MeSH Prohlížeč
• equol MeSH
• glycitein MeSH Prohlížeč
• isoflavony MeSH

BACKGROUND: Isoflavonoids seem to possess positive cardiovascular and other beneficial effects in humans. HYPOTHESIS: Their low bioavailability, however, indicates that small isoflavonoid metabolites formed by human microflora can significantly contribute to these activities. STUDY DESIGN: Testing antiplatelet activity ex vivo in human blood and interaction with transition metals in vitro. METHODS: The effect on platelet aggregation induced by different triggers (arachidonic acid, collagen, ADP, TRAP-6), and interactions with transition metals (iron and copper chelation/reduction) were evaluated against four isoflavonoid-specific metabolites: S-equol; O-desmethylangolensin; 2-(4-hydroxyphenyl) propionic acid (HPPA); and 4-ethylphenol. RESULTS: S-equol, 4-ethylphenol and O-desmethylangolensin blocked platelet aggregation induced by arachidonic acid and collagen. S-equol even matched the potency of acetylsalicylic acid in the case of collagen, which is the most physiological inducer of aggregation. Moreover, their effects in general seemed to be biologically relevant and attainable at achievable plasma concentrations, with the exception of HPPA which was ineffective. While only O-desmethylangolensin mildly chelated iron and copper, all four compounds markedly reduced cupric ions. Their direct free radical scavenging effects seem to have little clinical relevance. CONCLUSION: This study has shown that S-equol, O-desmethylangolensin and 4-ethylphenol, arising from isoflavonoid intake, can have biologically relevant effects on platelet aggregation.

• Klíčová slova
• Aggregation, Equol, Ethylphenol, Isoflavone, O-desmethylagolensin,
• MeSH
• agregace trombocytů účinky léků   MeSH
• Aspirin farmakologie   MeSH
• biologická dostupnost MeSH
• equol metabolismus   MeSH
• fenoly metabolismus   MeSH
• isoflavony metabolismus   farmakologie   MeSH
• lidé MeSH
• měď metabolismus   MeSH
• trombocyty účinky léků   MeSH
• železo metabolismus   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 4-ethylphenol MeSH Prohlížeč
• Aspirin MeSH
• equol MeSH
• fenoly MeSH
• isoflavony MeSH
• měď MeSH
• O-desmethylangolensin MeSH Prohlížeč
• železo MeSH

OBJECTIVE: Comparison of phytoestrogen treatment efficacy in menopausal women with and without ability to metabolise phytoestrogens. DESIGN: Clinical trial. SETTING: Department of Obstetrics and Gynaecology, Regional Hospital, Mlada Boleslav. METHODS: 28 menopausal women were treated with phytoestrogens in dose 80 mg daily. Before start and after finishing of treatment urinary concentrations of active metabolite S-equol were measured using ELISA method. Similarly before and after treatment Kupperman's index was measured. Patients with urinary concentrations of S-equol above 1 ng/ml were considered as S-equol producers, remaining patients formed control group. RESULTS: 16 out of 28 women were considered as S-equol producers, remainig 12 as a non-producers. Initial urinary concentrations of S-equol were 0.34 +/- 0.37 ng/ml in producers group and 0.29 +/- 0.30 ng/ml in non-producers. After finishing of therapy urinary concentration of S-equol increased to 10.67 +/- 11.57 ng/ml (p = 0.002) in producers group and 0.34 +/- 0.30 ng/ml (p = 0.701) in non-producers. Kupperman's index values were 23.44 +/- 11.57 in producers group and 17.25 +/- 7.78 in non-producers. After therapy value of Kupperman's index decreased to 14.44 +/- 9.97 (p = 0.003) in producers and to 12.00 +/- 7.18 (p = 0.100) in non-producers. No correlation between improvement in Kupperman's index and urinary concentration of S-equol after therapy was found similarly as between urinary concentration of S-equol before and after therapy in producents group. CONCLUSION: Significant phytoestrogen treatment effect in menopausal women producing S-equol was proven. Testing method for S-equol production introduced by our team togehter with suggested threshold urine concentration level of 1 ng/ml allows precise distinction of producers and non-producers of S-equol and subsequently to predict better treatment effect of phytoestrogens.

• MeSH
• beta receptor estrogenů agonisté   MeSH
• equol moč   MeSH
• fytoestrogeny terapeutické užití   MeSH
• lidé MeSH
• menopauza účinky léků   moč   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• beta receptor estrogenů MeSH
• equol MeSH
• fytoestrogeny MeSH

Phytoestrogens are naturally occurring nonsteroidal phenolic plant compounds that, due to their molecular structure and size, resemble vertebrate steroids estrogens. This review is focused on plant flavonoids isoflavones, which are ranked among the most estrogenic compounds. The main dietary sources of isoflavones for humans are soybean and soybean products, which contain mainly daidzein and genistein. When they are consumed, they exert estrogenic and/or antiestrogenic effects. Isoflavones are considered chemoprotective and can be used as an alternative therapy for a wide range of hormonal disorders, including several cancer types, namely breast cancer and prostate cancer, cardiovascular diseases, osteoporosis, or menopausal symptoms. On the other hand, isoflavones may also be considered endocrine disruptors with possible negative influences on the state of health in a certain part of the population or on the environment. This review deals with isoflavone classification, structure, and occurrence, with their metabolism, biological, and health effects in humans and animals, and with their utilization and potential risks.

• Klíčová slova
• biochanin A, daidzein, equol, formononetin, genistein, glycitein, isoflavones, phytoestrogens,
• MeSH
• equol chemie   klasifikace   metabolismus   MeSH
• fytoestrogeny chemie   klasifikace   metabolismus   MeSH
• genistein chemie   klasifikace   metabolismus   MeSH
• isoflavony chemie   klasifikace   metabolismus   MeSH
• lidé MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• biochanin A MeSH Prohlížeč
• daidzein MeSH Prohlížeč
• equol MeSH
• formononetin MeSH Prohlížeč
• fytoestrogeny MeSH
• genistein MeSH
• glycitein MeSH Prohlížeč
• isoflavony MeSH

Milk and dairy products are important sources of nutrients in the human diet because they contain a number of essential substances and other biologically active components. Many of these substances can be modified, and thus offer opportunities to use milk and dairy products as functional food. Isoflavones are particularly important in human nutrition due to their diverse pharmacological and antioxidant properties. The clinical effectiveness of isoflavone-rich products is believed to be dependent on their ability to metabolize daidzein to equol, which may directly exert cancer preventive effects. However, only approximately 30-40% of humans are able to produce equol, while animals, in general, produce equol. Equol is the predominant product of bacterial metabolism of isoflavones and can be found in various amounts in some food of animal origin, especially in milk. Therefore, milk and dairy products can be considered to be sources of equol for humans who are not able to produce this metabolite. When the content of isoflavones in milk is to be modified, two groups of factors should be considered, i.e., dietary factors that include the source of isoflavones and the processing effects on feedstuffs and animal factors that include the intake of isoflavones, ruminal and postruminal changes, and the health and physiological status of animals. The approximate content of isoflavones in milk can be predicted using carry-over rates for different dietary sources or using a formula that describes the relationship between equol concentration in milk and formononetin intake. Processing and storage can affect the content and profile of isoflavones in milk and dairy products.

• Klíčová slova
• carry-over, cows, dairy, health, isoflavone, metabolism,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The degradation of red clover isoflavones was studied in vitro using a rumen fluid buffer system. Various amounts of red clover extract (5-75 mg) together with hay or concentrate-rich diet were added to 40 ml of rumen fluid obtained from non-lactating and lactating dairy cows, respectively, and incubated for 0, 3, 6, 12 or 24 hr. Following incubation, concentrations of daidzein, genistein, formononetin, biochanin A and equol were determined in the samples. After 3 hr of incubation, isoflavone metabolism and equol production could be observed. The results obtained indicate that hay diet provides better conditions for isoflavone metabolism, as concentrations of daidzein, formononetin and biochanin A were higher in incubations based on the concentrate-rich diet and the production of equol was higher in incubations based on the hay diet. Furthermore, in incubations with higher amounts of added clover extract, a decrease in equol production was observed. Further studies are needed to clarify the role of adaptation of rumen microflora on isoflavone degradation kinetics and to clarify the interrelationship between various dietary factors, rumen microbiota and isoflavones. The knowledge of isoflavone metabolism kinetics in dependence on studied factors will be useful for the optimization of feeding dose.

• Klíčová slova
• Isoflavone, diet, equol, metabolism, rumen fluid,
• MeSH
• bachor MeSH
• dieta veterinární   MeSH
• isoflavony * MeSH
• laktace MeSH
• skot MeSH
• Trifolium * MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• isoflavony * MeSH

The aim of this study was to determine the degradation of dietary isoflavones in rumen fluid under 2 feeding regimens. The experiments were performed in vitro using a rumen fluid buffer system. The rumen fluid was taken from cows fed either a hay diet or a concentrate-rich diet (the diet consisted of 34.6% maize silage, 17.6% haylage, 12.8% alfalfa hay, and 35.0% supplemental mixture on a dry matter basis). As a source of isoflavones, 40% soybean extract (Biomedica, Prague, Czech Republic) at levels of 5, 25, 50, and 75 mg per 40 mL of rumen fluid was used. Samples of soybean extract were incubated in triplicate at 39°C for 0, 3.0, 6.0, 12.0, and 24.0 h in incubation solution. The metabolism of daidzein and genistein was faster under concentrate-rich diet conditions. In general, production of equol started after 3 to 6 h of incubation and reached the highest rate after approximately 12 h of incubation regardless of the type of diet or concentration of extract. In most of the experiments, production of equol continued after 24 h of incubation. Generally, equol production was greater under the hay diet conditions. Furthermore, experiments with higher amounts of added soybean extract revealed possible inhibitory effects of high levels of isoflavones on the rumen microflora.

• Klíčová slova
• cattle diet, equol, isoflavones, rumen,
• MeSH
• bachor metabolismus   MeSH
• dieta MeSH
• fyziologie výživy zvířat fyziologie   MeSH
• isoflavony aplikace a dávkování   analýza   metabolismus   MeSH
• krmivo pro zvířata MeSH
• laktace MeSH
• siláž MeSH
• skot MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• isoflavony MeSH

Isoflavones are natural phytoestrogens with antioxidant and endocrine-disrupting potencies. Monitoring of their levels is important to ensure the high quality and safety of food, milk, and dairy products. The efficiency and accuracy of phytoestrogen analyses in complex matrices such as milk depend on the extraction procedure, which often uses hydrolysis by means of the β-glucuronidase/sulfatase enzyme originating from Helix pomatia. The present study reveals that the commercially available hydrolytic enzyme is contaminated by several phytoestrogen isoflavones (genistein, daidzein, formononetin, and biochanin A) and their metabolite equol, as well as flavones (naringenin and apigenin) and coumestrol. We show that the concentrations of daidzein and genistein in the enzyme could have impaired the results of analyses of the main isoflavones in several previously published studies. Of 8 analyzed compounds, only equol was confirmed in the present study and it serves as a reliable marker of phytoestrogens originating from cow feed. Critical reassessment of phytoestrogen concentrations in milk is needed because several previously published studies might have overestimated the concentrations depending on the extraction procedure used.

• Klíčová slova
• bovine milk, equol, mass spectrometry, phytoestrogen,
• MeSH
• fytoestrogeny * MeSH
• glukuronidasa MeSH
• isoflavony MeSH
• kumestrol MeSH
• mléko chemie   MeSH
• ovum MeSH
• skot MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fytoestrogeny * MeSH
• glukuronidasa MeSH
• isoflavony MeSH
• kumestrol MeSH

1. The possibility of interaction of isoflavonoids with concomitantly taken drugs to determined isoflavonoids safety was studied. Inhibition of nine forms of cytochrome P450 (CYP3A4, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2C9, CYP2D6 and CYP2E1) by 12 isoflavonoids (daidzein, genistein, biochanin A, formononetin, glycitein, equol and six glucosides, daidzin, puerarin, genistin, sissotrin, ononin and glycitin) was studied systematically. 2. The most potent inhibitors were genistein and daidzein inhibiting noncompetitively the CYP2C9 with Ki of 35.95 ± 6.96 and 60.56 ± 3.53 μmol/l and CYP3A4 (inhibited by genistein with Ki of 23.25 ± 5.85 μmol/l also by a noncompetitive mechanism). Potent inhibition of CYP3A4 was observed also with biochanin A (Ki of 57.69 ± 2.36 μmol/l) and equol (Ki of 38.47 ± 2.32 μmol/l). 3. Genistein and daidzein inhibit noncompetitively CYP3A4 and CYP2C9. With plasma levels in micromolar range, a clinically important interaction with concomitantly taken drugs does not seem to be probable.

• Klíčová slova
• Daidzein, drug interactions, genistein, inhibition studies,
• MeSH
• cytochrom P-450 CYP1A2 MeSH
• cytochrom P450 CYP2C19 MeSH
• glukosidy MeSH
• isoflavony metabolismus   MeSH
• jaterní mikrozomy enzymologie   MeSH
• játra enzymologie   MeSH
• lékové interakce MeSH
• lidé MeSH
• systém (enzymů) cytochromů P-450 metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• calycosin-7-O-beta-D-glucoside MeSH Prohlížeč
• CYP1A2 protein, human MeSH Prohlížeč
• cytochrom P-450 CYP1A2 MeSH
• cytochrom P450 CYP2C19 MeSH
• formononetin MeSH Prohlížeč
• genistin MeSH Prohlížeč
• glukosidy MeSH
• glycitein MeSH Prohlížeč
• glycitin MeSH Prohlížeč
• isoflavony MeSH
• puerarin MeSH Prohlížeč
• systém (enzymů) cytochromů P-450 MeSH

Membrane organic anion-transporting polypeptides (OATPs) are responsible for the drug transmembrane transport within the human body. The function of OATP2B1 transporter can be inhibited by various natural compounds. Despite increased research interest in soya as a part of human diet, the effect of its active components to interact with hOATP2B1 has not been elucidated in a complex extent. This in vitro study examined the inhibitory effect of main soy isoflavones (daidzin, daidzein, genistin, genistein, glycitin, glycitein, biochanin A, formononetin) and their metabolites formed in vivo (S-equol, O-desmethylangolensin) towards human OATP2B1 transporter. MDCKII cells overexpressing hOATP2B1 were employed to determine quantitative inhibitory parameters of the tested compounds and to analyze mechanism/s of the inhibitory interaction. The study showed that aglycones of soy isoflavones and the main biologically active metabolite S-equol were able to significantly inhibit hOATP2B1-mediated transport. The Ki values for most of aglycones range from 1 to 20 μM. In contrast, glucosides did not exhibit significant inhibitory effect. The kinetic analysis did not indicate a uniform type of inhibition towards the hOATP2B1 although predominant mechanism of inhibition seemed to be competitive. These findings may suggest that tested soy isoflavones and their metabolites might affect transport of xenobiotics including drugs across tissue barriers via hOATP2B1.

• Klíčová slova
• Drug transporter, Flavonoids, OATP, SLCO, Soy isoflavones,
• MeSH
• buňky MDCK MeSH
• Glycine max * MeSH
• isoflavony farmakologie   MeSH
• kinetika MeSH
• přenašeče organických aniontů antagonisté a inhibitory   genetika   metabolismus   MeSH
• psi MeSH
• transfekce MeSH
• zvířata MeSH
• Check Tag
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• isoflavony MeSH
• přenašeče organických aniontů MeSH
• SLCO2B1 protein, human MeSH Prohlížeč