Effective methods for increasing coumestrol in soybean sprouts

Coumestrol (CM), a biologically active compound found in Leguminosae plants, provides various human health benefits. To identify easy and effective methods to increase CM content in vegetables, we developed a quantitative analysis method using high-performance liquid chromatography (HPLC). Using this method, we found that soybean sprouts (1.76 ± 0.13 μg/g) have high CM contents among nine vegetables and evaluated the difference in CM contents between two organs of the sprouts: cotyledons and hypocotyls. Next, soybean sprouts were cultivated under different light, temperature, and water conditions and their CM contents were evaluated. CM content was higher in hypocotyls (4.11 ± 0.04 μg/g) than in cotyledons. Cultivating soybean sprouts at 24°C enhanced CM content regardless of light conditions, the growth of fungi and bacteria, and sprout color. Thus, we identified methods of soybean sprout cultivation to increase CM content, which may provide health benefits and enhance value.

Unsubstituted metallophthalocyanine catalysts for the removal of endocrine disrupting compounds using H2O2 as oxidant

Advanced oxidation processes have become increasingly important to treat non-biodegradable compounds entering environmental waters. In recent decades, water-soluble metallophthalocyanines have been shown to catalyse H₂O₂-containing oxidation reactions through the production of unique reactive species, nucleophilic metal-peroxo complexes. Few reports in the literature have examined water insoluble metallophthalocyanines (MPc). The oxidative catalytic activity of water insoluble manganese- and iron-phthalocyanine (MnPc, FePc) at pH 7 has been shown through the decolourisation of methylene blue and removal of bisphenol A. These studies expand on this previous study, exploring the catalytic activity of a range of metallophthalocyanines catalysts under both acidic and neutral conditions. FePc, while only active under neutral conditions, was the best performing catalyst. This activity was significantly improved upon by the addition of acetonitrile as a co-solvent, as well as increasing the ratio of H₂O₂ to catalyst. MnPc was catalytically active at both pH 3 and 7. FePc and MnPc catalysts showed the ability to remove bisphenol A in the presence of dam water. Reaction rates were reduced for bisphenol A removal with FePc as a catalyst but were unchanged in the presence of MnPc. The removal of 17β-estradiol, estrone, and coumestrol was successfully demonstrated, with greater than 96% removal of all tested EDC's achieved. This is the first reported study showing the removal of the phytoestrogen, coumestrol. Even though considerably lower concentrations of costly catalysts and oxidation reagents were used in our work, the removal extent of EDC's by the MPc-catalysed oxidation reactions achieved here compares favourably with literature.

[UPLC-MS / MS for the pharmacokinetics of icariin in rats]

OBJECTIVE

To establish an ultra-performance liquid chromatographytandem mass spectrometry( UPLC-MS / MS) method for the quantification of icariin( ICA), and investigate pharmacokinetics of ICA in rats following multiple oral administration.

METHODS

ICA and an internal standard coumestrol( CMT) were extracted from rat plasma using ethyl acetate and separated on a BEH C18( 50 mm × 2. 1mm, 1. 7 μm) column using a gradient mobile phase of acetonitrile containing 0. 1%( V / V)formic acid and water containing 2 mmol / L ammonium formate at a flow rate of 0. 3m L / min. In negative electrospray ionization mode, multiple reaction monitoring of the precursor-product ion transitions of m / z 675. 6→351. 1 for ICA, 267. 0 →211. 1 for CMT was used for the quantification. Plasma was collected after rats were orally administered with ICA at multiple doses of 50 mg / kg.

RESULTS

The linear calibration curve was achieved in a concentration range of 0. 5-50 ng / m L with a lower limit of quantification of0. 5 ng / m L. The value of intra- and inter-day precision was less than 11. 3% and accuracy fell in the ranges of 94. 3%-98. 7%. The recovery ranged from 81. 3% to85. 2% and the matrix effects from 94. 3% to 103. 2%. After oral administration of ICA to rats, t1 /2was( 1. 68 ± 0. 29) h, Cmaxwas( 29. 6 ± 5. 3) ng / m L, tmaxwas( 1. 00 ± 0. 00) h, AUC0- twas( 88. 4 ± 13. 9)( h·ng) / m L.

CONCLUSION

The method is specific and accurate, suitable for preclinical pharmacokinetics of ICA.

Occurrence of isoflavonoids in Brazilian common bean germplasm (Phaseolus vulgaris L.)

Common bean (Phaseolus vulgaris) is present in the daily diet of various countries and, as for other legumes, has been investigated for its nutraceutical potential. Thus, 16 genotypes from different gene pools, representing seven types of seed coats and different responses to pathogens and pests, were selected to verify their isoflavone contents. The isoflavonoids daidzein and genistein and the flavonols kaempferol, myricetin, and quercetin were found. Grains of the black type showed the highest concentrations of isoflavonoids and were the only ones to exhibit daidzein. IAC Formoso, with high protein content and source of resistance to anthracnose, showed the greatest concentration of genistein, representing around 11% of the content present in soybean, as well as high levels of kaempferol. Arc 1, Raz 55, and IAC Una genotypes showed high content of coumestrol. The results suggest the use of IAC Formoso to increase the nutraceutical characteristics in common bean.

Distribution of isoflavones and coumestrol in neglected tropical and subtropical legumes

BACKGROUND

Isoflavones and coumestrol from dietary legumes are plant constituents showing multiple beneficial effects on humans. Owing to their ability to bind with mammalian estrogenic receptors and thereby intervention in several kinds of hormone-related cancers, they have received much attention. Soybean (Glycine max) is currently the major source of isoflavonoids in human diet. However, dozens of tropical and subtropical leguminous species remain unexplored for their isoflavonoids content.

RESULTS

We have analyzed 55 extracts from 41 tropical and subtropical legume species used either in human or animal diet by high-performance liquid chromatography for the content of soy isoflavones, biochanin A, daidzein, daidzin, formononetin, genistein, genistin, sissotrin, ononin and the coumestan coumestrol. Genistein and biochanin A were the most abundant compounds. The highest content of genistein was found in aerial parts of Andira macrothyrsa, seeds of Pachyrhizus tuberosus and aerial parts of Calopogonium mucunoides (598, 250 and 184 µg g(-1), respectively) and biochanin A in aerial parts of Cratylia argentea, C. mucunoides and flowers of A. macrothyrsa (76, 53 and 40 µg g(-1), respectively).

CONCLUSION

None of the samples tested was richer overall source of soy isoflavones and coumestrol than soybean; nevertheless several species (C. mucunoides or A. macrothyrsa) may serve as a promising source of individual compounds.

[Simultaneous determination of four kinds of furocoumarins in cosmetics by high performance liquid chromatography]

OBJECTIVE

A high performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of 4 furocoumarins, including 8-methoxycoumarin, 5-methoxycoumarin, trioxsalen and imperatorin in cosmetics.

METHODS

The separation was carried on Diamonsil C18 column (4.6 mm x 250 mm, 5 microm) by gradient elution with methanol-water as mobile phase at a flow rate of 1.0 ml/min and column temperature of 30 degrees C. The analysis of 4 furocoumarins was performed by HPLC with diodearray detector at the wavelength of 248 nm.

RESULTS

Identification of 4 furocoumarins was achieved by retention time, and quantification analysis was performed by the external standard method. The limits of quantitation (LOQ) for 4 furocoumarins were 0.54, 0.52, 0.58 and 0.50 microg/g, respectively. The method showed a good linearity in the range of 0.05-10 microg/ml with correlation coefficients more than 0.999. The mean recoveries at spiked levels were in the range of 89.9%-105.2% with RSDs of 0.20%-1.08%.

CONCLUSION

The method was accurate and simple, and was suitable for the determination of 4 furocoumarins in cosmetics.

LC analysis of coumestrol incorporated into topical lipid nanoemulsions

A simple, rapid, and sensitive LC method to determine coumestrol incorporated in the lipid nanoemulsions was validated. The analyses were performed at room temperature on a reversed-phase C18 column using a mobile phase composed of methanol/water with 0.1% trifluoracetic acid (70:30, v/v) at 0.8 mL min(-1). The detection was carried out on a UV detector at 343 nm. The linearity, in the range of 0.1-6.0 microg/mL, presented a determination coefficient (r2) of 0.999, calculated by the least square method. No interferences of the oil core or the gelling excipients were detected. The R.S.D. values for intra- and inter-day precision experiments were lower than 2%. The recovery ranged from 99.42% to 100.72%. Finally, the proposed method was successfully applied to determine coumestrol incorporated in the proposed topical formulations.

Occurrence and mass balance of isoflavones on an experimental grassland field

Isoflavones and coumestrol (COU) are estrogenic compounds that are naturally produced by plants (e.g., red clover, soybeans). Although these compounds have been extensively studied in food and feed, only little is known about their environmental fate. Therefore, we investigated the occurrence of isoflavones (formononetin, daidzein, equol, biochanin A, and genistein) and COU over 3.5 years in red clover, manure, and soil of a grassland field with and without manure application, as well as their emission via drainage water. Isoflavones were regularly quantified in plant (≤ 15 × 10(6) ng/g(dry weight (dw))), manure (≤ 230 × 10(3) ng/g(dw)), soil (≤ 3.4 × 10(3) ng/g(dw)), and drainage water samples (≤ 3.6 × 10(3) ng/L). In contrast, COU was observed only in manure and soil. Cumulative isoflavone loads emitted via drainage water were around 0.2 × 10(-3) kg/ha/y, which is very little compared to the amounts present in red clover (105-220 kg/ha/y), manure (0.5-1.0 kg/ha/y), and soil (0.1-5.1 kg/ha/y). Under good agricultural practice, no additional emission of isoflavones into drainage water was observed after manure application. With calculated 17β-estradiol equivalents up to 0.46 ng/L in drainage water, isoflavones can constitute a dominant and ecotoxicological relevant portion of the total estrogenicity in small rural river catchments.

Occurrence and mass balance of isoflavones on an experimental grassland field

Isoflavones and coumestrol (COU) are estrogenic compounds that are naturally produced by plants (e.g., red clover, soybeans). Although these compounds have been extensively studied in food and feed, only little is known about their environmental fate. Therefore, we investigated the occurrence of isoflavones (formononetin, daidzein, equol, biochanin A, and genistein) and COU over 3.5 years in red clover, manure, and soil of a grassland field with and without manure application, as well as their emission via drainage water. Isoflavones were regularly quantified in plant (≤ 15 × 10(6) ng/g(dry weight (dw))), manure (≤ 230 × 10(3) ng/g(dw)), soil (≤ 3.4 × 10(3) ng/g(dw)), and drainage water samples (≤ 3.6 × 10(3) ng/L). In contrast, COU was observed only in manure and soil. Cumulative isoflavone loads emitted via drainage water were around 0.2 × 10(-3) kg/ha/y, which is very little compared to the amounts present in red clover (105-220 kg/ha/y), manure (0.5-1.0 kg/ha/y), and soil (0.1-5.1 kg/ha/y). Under good agricultural practice, no additional emission of isoflavones into drainage water was observed after manure application. With calculated 17β-estradiol equivalents up to 0.46 ng/L in drainage water, isoflavones can constitute a dominant and ecotoxicological relevant portion of the total estrogenicity in small rural river catchments.

Quantification of phytoestrogens in industrial waste streams

Chemical compounds, including plant-based phytoestrogens, can function as hormone mimics and alter endocrine signaling in wildlife. In the present study, the waste streams from 19 plant-processing industries, including biofuel manufacturers, were sampled and analyzed for the phytoestrogens genistein, daidzein, coumestrol, formononetin, biochanin A, and zearalenone, via liquid chromatography/mass spectrometry. Eight of these industries contained phytoestrogens at environmentally relevant levels (≥1,000 ng/L), with the highest at approximately 250,000 ng/L. The influent and effluent streams of three municipal wastewater treatment plants receiving flow from some of these industries also were sampled and analyzed for the same phytoestrogens. It appeared that aerobic biological treatment, such as activated sludge, was able to remove these compounds from the liquid stream. Nevertheless, the effluent stream from one of the wastewater treatment plants had a phytoestrogen concentration above 1,000 ng/L. Results of the present study indicate the need for caution when designing facilities to treat the effluents from biofuel and other plant-processing industries.

A Medicago truncatula mutant hyper-responsive to mycorrhiza and defective for nodulation

One key strategy for the identification of plant genes required for mycorrhizal development is the use of plant mutants affected in mycorrhizal colonisation. In this paper, we report a new Medicago truncatula mutant defective for nodulation but hypermycorrhizal for symbiosis development and response. This mutant, called B9, presents a poor shoot and, especially, root development with short laterals. Inoculation with Glomus intraradices results in significantly higher root colonisation of the mutant than the wild-type genotype A17 (+20% for total root length, +16% for arbuscule frequency in the colonised part of the root, +39% for arbuscule frequency in the total root system). Mycorrhizal effects on shoot and root biomass of B9 plants are about twofold greater than in the wild-type genotype. The B9 mutant of M. truncatula is characterised by considerably higher root concentrations of the phytoestrogen coumestrol and by the novel synthesis of the coumestrol conjugate malonyl glycoside, absent from roots of wild-type plants. In conclusion, this is the first time that a hypermycorrhizal plant mutant affected negatively for nodulation (Myc(++), Nod (-/+) phenotype) is reported. This mutant represents a new tool for the study of plant genes differentially regulating mycorrhiza and nodulation symbioses, in particular, those related to autoregulation mechanisms.

Phytoestrogen content of beverages, nuts, seeds, and oils

Phytoestrogens are secondary plant metabolites that have received increasing attention for their bioactivity, in particular due to their structural and functional similarity to 17beta-estradiol. Although urinary and plasma phytoestrogens can be used as biomarkers for dietary intake, this is often not possible in large epidemiological studies or in the assessment of general exposure in free-living individuals. Accurate information about dietary phytoestrogens is therefore important, but there are very limited data concerning food contents. In this study was analyzed a comprehensive selection of tea, coffee, alcoholic beverages, nuts, seeds, and oils for their phytoestrogen content using a newly developed sensitive method based on LC-MS incorporating (13)C 3-labeled standards. Phytoestrogens were detected in all foods analyzed, although the contents in gin and bitter (beer) were below the limit of quantification (1.5 microg/100 g). Lignans were the main type of phytoestrogens detected. Tea and coffee contained up to 20 microg/100 g phytoestrogens and beer (except bitter) contained up to 71 microg/100 g, mainly lignans. As these beverages are commonly consumed, they are a main source of dietary lignans. The results published here will contribute to databases of dietary phytoestrogen content and allow a more accurate determination of phytoestrogen exposure in free-living individuals.

Estimated intakes of isoflavones and coumestrol in Korean population

The dietary intakes and sources of isoflavones and coumestrol were estimated for each age group of Koreans based on data from the Korean Nutrition Survey conducted in 1998. For quantitative data on the levels of isoflavones and coumestrol, our previous study monitoring phytoestrogens in 220 Korean leguminous foodstuffs was employed and the median value for each food was adopted. The total isoflavones and coumestrol intake per capita was estimated as 23.3 mg/day, which constituted 14.2 mg daidzein, 6.7 mg genistein, 0.9 mg glycitein, 1.0 mg formononetin, 0.2 mg biochanin A, and 0.3 mg coumestrol. The top five foods arrowroot, soybean paste, tofu, soybean, and soybean sprout contributed to 88.2% of isoflavone intake, with the corresponding intake from each food being 8.3 mg/day, 4.9 mg/day, 2.6 mg/day, 2.5 mg/day, and 2.0 mg/day, respectively. Starting at age 3-6, the contributions of fermented soy products to the isoflavones intakes were around 30%. Soybean sprout was a major source of coumestrol intake in Koreans. Slight differences in the preference of these foods were observed among the various age groups. As regards the total isoflavone intakes, the highest value was 33.6 mg/day for people age 30-49, followed by age 50-64 (26.4 mg/day), 20-29 (21.0 mg/day), >or=65 (18.8 mg/day), 1-2 (14.5 mg/day), 7-12 (12.4 mg/day), 13-19 (10.1 mg/day), and 3-6 (8.9 mg/day). The intake levels are likely to be exceeded in groups who have preferably consumed high phytoestrogen-containing foods such as soy-protein-based infant formula and arrowroot.

Glyphosate-tolerant alfalfa is compositionally equivalent to conventional alfalfa (Medicago sativa L.)

Glyphosate-tolerant alfalfa (GTA) was developed to withstand over-the-top applications of glyphosate, the active ingredient in Roundup agricultural herbicides. As a part of the safety assessment, GTA (designated J101 x J163) was grown under controlled field conditions at geographically diverse locations within the United States during the 2001 and 2003 field seasons along with control and other conventional alfalfa varieties for compositional assessment. Field trials were conducted using a randomized complete block design with four replication blocks at each site. Alfalfa forage was harvested at the late bud to early bloom stage from each plot at five field sites in 2001 (establishment year) and from four field sites in 2003 (third year of stand). The concentration of proximate constituents, fibers, amino acids, coumestrol, and minerals in the forage was measured. The results showed that the forage from GTA J101 x J163 is compositionally equivalent to forage from the control and conventional alfalfa varieties.

Synthesis of hapten and conjugates of coumestrol and development of immunoassay

3-O-Carboxymethylcoumestrol was prepared as the hapten for immunoassay by a partial alkylation of coumestrol with ethyl chloroacetate in acetone alkalized with potassium carbonate. 3-O-Ethoxycarbonylmethylcoumestrol was separated by column chromatography and finally was hydrolyzed with formic acid. 1H and 13C NMR data (APT, COSY, HMQC, and HMBC) revealed that the reaction was regioselective, as 3-O-ethoxycarboxymethylcoumestrol was the only monosubstituted derivative. The hapten was then conjugated to bovine serum albumin and used for immunization of rabbits. A radioimmunoassay (RIA) system was established based on the polyclonal antiserum and a 125I-labeled hapten-tyrosine methyl ester conjugate as the radioligand. Parameters of the RIA: sensitivity: 12 pg per tube, 50% intercept: 140 pg per tube, working range: 20-4000 pg per tube. The cross-reactivity of a panel isoflavonoid and lignan phytoestrogens was either negligible (e.g. formononetin 0.07%; biochanin A 0.06%) or not detectable at all. The major immunoreactive peak in HPLC fractions from an alfalfa extract had the same retention time as coumestrol standard and represented 94.8% of the signal. The remaining 5.2% of immunoreactivity was distributed between five minor peaks. We conclude that after the validation for particular matrices, the method will be a useful tool for analysis of coumestrol, especially in low volume and low concentration samples.

Detection of phytoestrogens in samples of second trimester human amniotic fluid

There is widespread concern that fetal exposure to hormonally active chemicals may adversely affect development of the reproductive tract. Therefore, the present study was performed to develop the necessary analytical methods and test the hypothesis that dietary phytoestrogens can be quantified in second trimester human amniotic fluid. Amniotic fluid samples (n=59) from women (n=53) undergoing routine amniocentesis between 15 and 23 weeks of gestation were analyzed by gas chromatography/mass spectrometric (GC/MS). Analytes included the phytoestrogens daidzein, genistein, formononetin, biochanin A, and coumestrol. Dietary phytoestrogens were quantified in 96.2% of second trimester amniotic fluid samples tested. The mean (+/- standard deviation (S.D.)) concentration of daidzein and genistein in amniotic fluid was 1.44 +/- 1.34 and 1.69 +/- 1.48 ng/ml with maximum levels of 5.52 and 6.54 ng/ml, respectively. Second trimester amniotic fluid contains quantifiable levels of dietary phytoestrogens and thus is a marker of mid pregnancy fetal exposure.

Quantitative determination of isoflavones and coumestrol in soybean by column liquid chromatography

Four different stationary phases and a variety of solvents in varying proportions were examined in this study. Daidzein, genistein, formononetin, biochanin A and coumestrol were separated within 24 min on a phenyl column with acetonitrile-water (33:67, v/v) as eluent. The proposed method showed an acceptable repeatability with a RSD of quantitation <6%. The mean recoveries of daidzein, genistein, formononetin, biochanin A and coumestrol from soybean ranged from 89 to 104%. The identity of the individual analytes was confirmed by LC-MS-MS. The four isoflavones and coumestrol were isolated from soybean by hydrolysis with acid and heat. Neutralization of the soybean samples prior to identification did not alter the concentration of daidzein and genistein in soybean.

Phytoestrogen content of purified, open- and closed-formula laboratory animal diets

BACKGROUND AND PURPOSE

Phytoestrogens exert estrogenic effects on the central nervous system, induce estrus, and stimulate growth of the genital tract of female animals. Over 300 plants and plant products, including some used in laboratory animal diets, contain phytoestrogens. Therefore, the source and concentration of phytoestrogens in rodent diets were determined.

METHODS

Twelve rodent diets and six major dietary ingredients were assayed for phytoestrogens (daidzein, genistein, formononetin, biochanin A, and coumestrol), using high-performance liquid chromatography. Three rodent diets recently formulated to reduce phytoestrogen content also were assayed.

RESULTS

Formononetin, biochanin A, and coumestrol were not detected. Soybean meal was the major source of daidzein and genistein; their concentrations were directly correlated to the percentage of soybean meal in each diet.

CONCLUSIONS

High, variable concentrations of daidzein and genistein are present in some rodent diets, and dietary phytoestrogens have the potential to alter results of studies of estrogenicity. Careful attention should be given to diet phytoestrogen content, and their concentration should be reported. A standardized, open-formula diet in which estrogenic substances have been reduced to levels that do not alter results of studies that are influenced by exogenous estrogens is recommended.

Isotope dilution gas chromatographic-mass spectrometric method for the determination of isoflavonoids, coumestrol, and lignans in food samples

We present a method for the quantitative determination of the phytoestrogens formononetin, biochanin A, daidzein, genistein, and coumestrol and simultaneously the lignans secoisolariciresinol (SECO) and matairesinol in plant-derived foods. These compounds are measured by isotope dilution gas chromatography-mass spectrometry in the selected ion monitoring mode (ID/GC/MS/SIM) using synthesized deuterated internal standards for the correction of losses during the procedure. A three-step hydrolysis--a rehydration with distilled H2O, followed by enzymatic and acid hydrolysis--has been applied in order to convert the diphenolic glycosides into their respective aglycones. Purification and separation are carried out in two ion-exchange chromatographic steps followed by derivatization and GC-MS. The within-assay imprecision values vary 3.1-9.6% and the between-assay imprecision 7.0-21.2%. The mean recovery of authentic standards processed through the whole procedure varied from 95.5 to 105.5%. Values for some different food samples are presented. The simultaneous determination of the biologically most interesting phytoestrogens and lignans in foods has not been carried out previously and the method will be useful for screening of important foods in populations with different risk of cancer and coronary heart disease, and for metabolic studies.

Rapid HPLC analysis of dietary phytoestrogens from legumes and from human urine

Due to growing evidence suggesting that phytoestrogens might protect against various cancers, particularly against breast and prostate cancer, it is important to measure the exposure of populations to these compounds by determining levels in food and in human tissue or body fluids to assess the possible cancer protective properties of these agents. Therefore, we developed a simple and fast procedure to extract and simultaneously hydrolyze phytoestrogens and their conjugates from food items, and present a fast and selective high-performance liquid chromatography (HPLC) method for precise determinations of the most common dietary phytoestrogens genistein, biochanin-A, daidzein, formononetin, and coumestrol using flavone as internal standard. For the first time HPLC was applied to measure these phytoestrogens and their most abundant metabolites equol and O-desmethyl-angolensin from human urine. The proposed methodology has been evaluated for losses due to thermal degradation during extraction and hydrolysis and due to sample handling during the entire work-up including solid phase extraction, and values are given for inter- and intra-assay variability. We present isoflavonoid levels of most common peas and beans used in "western" and "eastern" diets and compare isoflavonoid and coumestrol levels of raw, canned, and cooked foods which can be used in future epidemiological studies. We also determined human urinary levels with our methodology comparing values before and after soybean intake.

Phytoestrogen content and estrogenic effect of legume fodder

This study is a summary of Finnish investigations of the phytoestrogen content of legume plants, red clover, white clover, alfalfa, and goat's rue. In addition to the chemical analyses, biological studies were performed. Uterine weight of immature rats was used as an indicator of the estrogenic effect of the fodder used. All red clover varieties studied contained estrogenic isoflavones, especially formononetin and biochanin-A. The phytoestrogen content varied from 1.0% to 2.5% of dry matter. The biological study of white clover showed a clear estrogenic effect not visible through chemical analysis. Alfalfa contains small quantities of formononetin and biochanin-A, but 25-65 ppm coumestrol in dry matter. The estrogenic effect of alfalfa was obvious in the biological study. Goat's rue did not contain any known phytoestrogens, and the biological study was completely negative.

Estrogenic effect of dietary soya bean meal on vitellogenesis in cultured Siberian sturgeon Acipenser baeri

The unusual presence of vitellogenin in the plasma of male and nonvitellogenic female Siberian sturgeon has been demonstrated previously (Pelissero and Le Menn, 1988; Pelissero et al., 1989a) and was attributed to dietary effects. The present study examines estrogenic effects of dietary soya bean meal and of commercial trout diet on vitellogenesis in sturgeon. The 4-month study compared three diets, one commercial (T) and two experimental synthetic diets, one containing casein alone (SC for synthetic diet made on casein), and the other casein and soya bean (SS for synthetic diet made with soya bean) as protein sources. The dietary soya bean meal contained plant isoflavonic compounds which are well known to mimic the effects of estrogens in mammals. The SC diet, free of estrogenic compounds, served as the reference diet. When fed with the SC diet, sturgeons showed significantly lower plasma vitellogenin levels (0.0045 +/- 0.0012 mg/ml) compared with those fed the commercial diet (1.24 +/- 0.37 mg/ml). The SS diet had a very pronounced effect on the plasma vitellogenin level, which at the end of the experiment had reached 6 mg vitellogenin/ml. In no case was estradiol detectable in the plasma. Plasma androgen levels were high in all the three groups throughout the study period, and not significantly different from one another. Sturgeon fed the T diet had larger livers, with enlarged hepatocytes, compared with those fed the SS and SC diets.

Liquid chromatographic determination of the estrogens daidzein, formononetin, coumestrol, and equol in bovine blood plasma and urine

A liquid chromatographic (LC) method is described for the determination of the plant estrogens diadzein, formononetin, and coumestrol and the estrogenically active metabolite equol in bovine blood plasma and urine. The blood and urine samples are incubated overnight with and without beta-glucuronidase/sulfatase for analysis of both free and conjugated forms of estrogens. Samples are applied to Extrelut columns, extracted with ethyl acetate, and evaporated to dryness. Residues from urine samples are dissolved in methanol, diluted with water, acidified with HCl, and purified by injection through a Sep-Pak C18 cartridge. This eluate is used for LC analysis. Residues from blood samples are dissolved in benzene-petroleum ether (1 + 1), extracted with ammonium hydroxide, acidified with glacial acetic acid, and extracted with ethyl acetate. The ethyl acetate extract is evaporated, dissolved in 80% methanol, injected onto a LC reverse-phase column, and separated in a linear gradient system between 40 and 80% methanol in phosphate buffer. Quantitation is performed by means of UV and fluorescence responses. The method was sensitive enough to determine 0.4 ng/mL of daidzein and formononetin and 0.1 and 13 ng/mL of coumestrol and equol, respectively, in blood, and 130, 80, and 7 ng/mL of daidzein, formononetin, and coumestrol, respectively, and 4 micrograms/mL of equol in urine. The applicability of the method was checked by the determination of total and free plant estrogens in blood samples from a dairy cow fed a normal diet.

Naturally occurring oestrogens in foods--a review

This review is concerned with the presence of naturally occurring oestrogens in food plants and processed foods. Particular emphasis is placed on isoflavones and coumestans, both of which are true plant oestrogens, and the resorcylic acid lactones, more correctly classified as fungal oestrogens. The metabolism and mode of action of these compounds is discussed and their biological potencies, determined in both in vivo and in vitro studies, described. Current methods of analysis are indicated and the levels of these oestrogens in food plants, processed foods and foodstuffs are presented. Botanical, environmental or technological factors affecting the possible intake of plant and fungal oestrogens are mentioned and the hazard associated with such intake is compared with that originating from other dietary or medicinal hormonally active substances. Indications are given of the wide range of common food plants which have been reported to possess oestrogenic (uterotropic) activity, although it is emphasized that in general further work is necessary to substantiate these claims and to confirm the identities of the biologically active principles which have in some cases been proposed. In the concluding section suggestions are made for additional research considered important or necessary in this interesting area.

Liquid chromatographic determination of the plant estrogens coumestrol and isoflavones in animal feed

A simplified procedure is described for the cleanup and determination of the 5 main plant estrogens in animal feed: coumestrol, genistein, biochanin A, daidzein, and formononetin. The estrogens are extracted with ethanol and purified on a Sep-Pak C18 cartridge. All 5 plant estrogens are separated in an isocratic liquid chromatographic system and quantitated by UV and fluorescence responses. The method is sensitive to about 2.5 ppm coumestrol and 10 ppm of the isoflavones.

Quantitative determination of coumestrol in dried alfalfa and alfalfa leaf protein concentrates containing chlorophyll

An improved analytical method for the determination of coumestrol in dried alfalfa and leaf protein concentrates is described. In this method, chlorophyll is removed from an alcohol extract prior to the paper chromatographic-fluorometric measurement of coumestrol. Ninety-eight per cent of the coumestrol added to alfalfa leaf protein concentrates is recovered by this method. This improved method gives replicate values with lower standard deviations and coefficients of variation than the literature method.