Review of the methods used in the determination of phytoestrogens

A critical review on organophosphate esters in drinking water: Analysis, occurrence, sources, and human health risk assessment

Organophosphate esters (OPEs) are ubiquitous in the environment. Copious studies assessed OPEs in various environmental media. However, there is limited summative information about OPEs in drinking water. This review provides comprehensive data for the analytical methods, occurrence, sources, and risk assessment of OPEs in drinking water. In general, liquid-liquid extraction and solid-phase extraction are the most common methods in the extraction of OPEs from drinking water, while gas chromatography and liquid chromatography are the most commonly used instrumental methods for detecting OPEs in drinking water. On the basis of these techniques, a variety of methods on OPEs pretreatment and determination have been developed to know the pollution situation of OPEs. Studies on the occurrence of OPEs in drinking water show that the total concentrations of OPEs vary seasonally and regionally, with tris(1-chloro-2-isopropyl) phosphate and tris(2-chloroethyl) phosphate dominant among different kinds of drinking water. Source identification studies show that there are three main sources of OPEs in drinking water: 1) source water contamination; 2) residual in drinking water treatment process; 3) leakage from device or pipeline. Besides, risk assessments indicate that individual and total OPEs pose no or negligible health risk to human, but this result may be significantly underestimated. Finally, the current knowledge gaps on the research of OPEs in drinking water are discussed and some suggestions are provided for future environmental research.

Effects of pomegranate peel and olive pomace supplementation on reproduction and oxidative status of rabbit doe

The current study aimed to investigate the effects of pomegranate peel and olive pomace supplementation on the reproductive hormones, antioxidative status, reproductive capacity and maternal behaviour of rabbit does. Forty does were used for the experiments. The animals were randomly assigned to four groups of ten does. One group was fed on the control diet and was considered the control group (C). The second group was supplemented with 4.5% pomegranate peel in their diet (P), the third group was supplemented with 10% olive pomace in their diet (O), and the fourth group was supplemented with a mixture of pomegranate peel and olive pomace (PO). Compared with the control does, group P showed significantly increased serum levels of gonadotropic hormones and oestradiol-17β two hours after mating, on the 20th day of lactation and after weaning; significantly increased progesterone levels at mid-pregnancy; and significantly increased in prolactin levels on the 10th day of lactation. Additionally, the results revealed significant increases in total DNA, protein concentration, litter size, milk yield and nest traits of groups P and PO. In conclusion, pomegranate peel supplementation improves the reproductive performance of does and increases their antioxidant parameters.

Estrogenic Effects of Extracts and Isolated Compounds from Belowground and Aerial Parts of Spartina anglica

Menopause, caused by decreases in estrogen production, results in symptoms such as facial flushing, vaginal atrophy, and osteoporosis. Although hormone replacement therapy is utilized to treat menopausal symptoms, it is associated with a risk of breast cancer development. We aimed to evaluate the estrogenic activities of Spartina anglica (SA) and its compounds and identify potential candidates for the treatment of estrogen reduction without the risk of breast cancer. We evaluated the estrogenic and anti-proliferative effects of extracts of SA and its compounds in MCF-7 breast cancer cells. We performed an uterotrophic assay using an immature female rat model. Among extracts of SA, belowground part (SA-bg-E50) had potent estrogenic activity. In the immature female rat model, the administration of SA-bg-E50 increased uterine weight compared with that in the normal group. Among the compounds isolated from SA, 1,3-di-O-trans-feruloyl-(-)-quinic acid (1) had significant estrogenic activity and induced phosphorylation at serine residues of estrogen receptor (ER)α. All extracts and compounds from SA did not increase MCF-7 cell proliferation. Compound 1 is expected to act as an ERα ligand and have estrogenic effects, without side effects, such as breast cancer development.

A brief history and spectroscopic analysis of soy isoflavones

The production of soybean continues to increase worldwide. People are showing more interest in the beneficial health effects of soybeans than before. However, the origin and history of soybeans are still being discussed among many researchers. Chromatographic methods enable the desirable separation of a variety of isoflavones from soybeans. The structures of isolated soy isoflavones have been successfully identified in tandem with spectroscopic analytical instruments and technologies such as liquid chromatography, mass spectrometry, and nuclear magnetic resonance spectroscopy. The theoretical background behind spectroscopy may help improve the understanding for the analysis of isoflavones in soybeans and soy-derived foods. This review covers the origin of the English name of soybean and its scientific name, Glycine max (L.) Merrill, based on the evidence reported to date. Moreover, the reports of soy isoflavones discovered over a period of about 100 years have been briefly reviewed.

Navarro MO, Andrade G, Lucas JA. Identifying the Compounds of the Metabolic Elicitors of Pseudomonas fluorescens N 21.4 Responsible for Their Ability to Induce Plant Resistance

In this work, the metabolic elicitors extracted from the beneficial rhizobacterium Pseudomonas fluorescens N 21.4 were sequentially fragmented by vacuum liquid chromatography to isolate, purify and identify the compounds responsible for the extraordinary capacities of this strain to induce systemic resistance and to elicit secondary defensive metabolism in diverse plant species. To check if the fractions sequentially obtained were able to increase the synthesis of isoflavones and if, therefore, they still maintained the eliciting capacity of the live strain, rapid and controlled experiments were done with soybean seeds. The optimal action concentration of the fractions was established and all of them elicited isoflavone secondary metabolism-the fractions that had been extracted with n-hexane being more effective. The purest fraction was the one with the highest eliciting capacity and was also tested in Arabidopsis thaliana seedlings to induce systemic resistance against the pathogen Pseudomonas syringae pv. tomato DC 3000. This fraction was then analyzed by UHPLC/ESI-QTOF-MS, and an alkaloid, two amino lipids, three arylalkylamines and a terpenoid were tentatively identified. These identified compounds could be part of commercial plant inoculants of biological and sustainable origin to be applied in crops, due to their potential to enhance the plant immune response and since many of them have putative antibiotic and/or antifungal potential.

The influence of phytoestrogens on different physiological and pathological processes: An overview

Functional foods have nutritional properties and organic functions, which are beneficial to health. Certain types of functional food components are so-called phytoestrogens, non-steroidal compounds derived from the metabolism of precursors contained in plants, which originate secondary metabotypes known to induce biological responses and by mimicry or modulating the action of endogenous estrogen. These molecules are involved in several physiological and pathological processes related to reproduction, bone remodeling, skin, cardiovascular, nervous, immune systems, and metabolism. This review aimed to present an overview of phytoestrogens regarding their chemical structure, actions, and effects in the organism given several pathologies. Several studies have demonstrated beneficial phytoestrogen actions, such as lipid profile improvement, cognitive function, menopause, oxidative stress, among others. Phytoestrogens effects are not completely elucidated, being necessary future research to understand the exact action mechanisms, whether they are via estrogen receptor or whether other hidden mechanisms produce these effects. Thus, this review makes a general approach to the phytoestrogen actions, beneficial effects, risk and limitations. However, the complexities of biological effects after ingestion of phytoestrogens and the differences in their metabolism and bioavailability indicate that interpretation of either risk or benefits needs to be made with caution.

Effect of Short-Course Oral Ciprofloxacin on Isoflavone Pharmacokinetics following Soy Milk Ingestion in Healthy Postmenopausal Women

Soy isoflavones have several potential benefits related to postmenopausal health. Isoflavone glycosides, found predominantly in nonfermented soy products, e.g., soy milk, require conversion by gut microbiota to their respective bioavailable aglycones prior to absorption into portal circulation. Use of short-course oral ciprofloxacin for the treatment of acute uncomplicated cystitis, the incidence of which is increasing among postmenopausal women, might adversely affect gut microbiota. The objective of this one-group pre-post treatment study was to determine the effect of short-course oral ciprofloxacin on isoflavone pharmacokinetics in healthy postmenopausal women. Eleven postmenopausal subjects were assigned to consume a single oral dose of 375 mL UHT soy milk (SOY phase). Blood samples were collected immediately before soy milk ingestion and at specific times for 32 hours after soy milk ingestion. Following a washout period of at least seven days, subjects were assigned to take 250 mg oral ciprofloxacin after breakfast and dinner for three days, followed by a single oral dose of 375 mL UHT soy milk the next day (CIPRO/SOY phase). Blood samples were collected at the same time points as in the SOY phase. Plasma samples were treated with β-glucuronidase/sulfatase and plasma concentrations of aglycones (genistein and daidzein) were determined using high-performance liquid chromatography. C_max, AUC_0-t, and AUC_0-∞ of both aglycones and T_max of genistein obtained from the CIPRO/SOY phase were significantly lower than those obtained from the SOY phase, while T_max of daidzein and t_1/2 of both aglycones in the two phases were not significantly different.

Analysis of Food by High Performance Liquid Chromatography Coupled with Coulometric Detection and Related Techniques: A Review

The development of single coulometric cells in combination with high performance liquid chromatography to dual cells and to the coulometric electrode array detector is described. An overview is given about the application of these methods in food chemistry. Easily oxidizable compounds, such as phenolic substances, pesticides, or vitamins, can be determined, as well as substances with high oxidation potentials or electroinactive compounds. Substances exhibiting poor electrochemical activity can be transformed to electroactive compounds by precolumn derivatization, postcolumn photochemical reactions, postcolumn enzyme reactors, or by using the oxidative/reductive mode for coulometric electrode array detection. Furthermore, it is shown that the interesting combination of high performance liquid chromatography with electrochemistry and mass spectrometry has opened further possibilities with respect to interpretation of redox reactions, drug metabolism studies, metabolomics, and electrochemical derivatization.

Active Components from Sea Buckthorn ( Hippophae rhamnoides L.) Regulate Hepatic Stellate Cell Activation and Liver Fibrogenesis

Sea buckthorn ( Hippophae rhamnoides L.) is a berry bearing multiple nutritional properties. In this study, 46 compounds were isolated from sea buckthorn berries. Preliminary data showed that the components, C13, C15, and C32, exhibited profound inhibitory effect on the activation of hepatic stellate cells (HSCs) induced by transforming growth factor-β (TGF-β) and decreased the levels of inflammatory factors. Furthermore, these compounds over-regulated the proteins of DNA damage signaling pathway and alpha-smooth muscle actin (α-SMA). Moreover, active components of sea buckthorn berry (ACSB) treatment attenuated fibrosis development in rats after bile duct ligation (BDL), reducing liver injury and inflammation, and reviving liver function in a dose-dependent manner. Moreover, ACSB down-regulated the expression of α-SMA, while over-regulating the DNA damage signaling pathway and the related genes. These suggest that ACSB inhibit DNA repair of HSCs, make them in a damaged state, inhibit the expression of TGF-β, and induce apoptosis.

Analytical techniques for steroid estrogens in water samples - A review

In recent years, environmental concerns over ultra-trace levels of steroid estrogens concentrations in water samples have increased because of their adverse effects on human and animal life. Special attention to the analytical techniques used to quantify steroid estrogens in water samples is therefore increasingly important. The objective of this review was to present an overview of both instrumental and non-instrumental analytical techniques available for the determination of steroid estrogens in water samples, evidencing their respective potential advantages and limitations using the Need, Approach, Benefit, and Competition (NABC) approach. The analytical techniques highlighted in this review were instrumental and non-instrumental analytical techniques namely gas chromatography mass spectrometry (GC-MS), liquid chromatography mass spectrometry (LC-MS), enzyme-linked immuno sorbent assay (ELISA), radio immuno assay (RIA), yeast estrogen screen (YES) assay, and human breast cancer cell line proliferation (E-screen) assay. The complexity of water samples and their low estrogenic concentrations necessitates the use of highly sensitive instrumental analytical techniques (GC-MS and LC-MS) and non-instrumental analytical techniques (ELISA, RIA, YES assay and E-screen assay) to quantify steroid estrogens. Both instrumental and non-instrumental analytical techniques have their own advantages and limitations. However, the non-instrumental ELISA analytical techniques, thanks to its lower detection limit and simplicity, its rapidity and cost-effectiveness, currently appears to be the most reliable for determining steroid estrogens in water samples.

Liquid chromatography with absorbance detection and with isotope-dilution mass spectrometry for determination of isoflavones in soy standard reference materials

Two independent analytical approaches, based on liquid chromatography with absorbance detection and liquid chromatography with mass spectrometric detection, have been developed for determination of isoflavones in soy materials. These two methods yield comparable results for a variety of soy-based foods and dietary supplements. Four Standard Reference Materials (SRMs) have been produced by the National Institute of Standards and Technology to assist the food and dietary supplement community in method validation and have been assigned values for isoflavone content using both methods. These SRMs include SRM 3234 Soy Flour, SRM 3236 Soy Protein Isolate, SRM 3237 Soy Protein Concentrate, and SRM 3238 Soy-Containing Solid Oral Dosage Form. A fifth material, SRM 3235 Soy Milk, was evaluated using the methods and found to be inhomogeneous for isoflavones and unsuitable for value assignment. Graphical Abstract Separation of six isoflavone aglycones and glycosides found in Standard Reference Material (SRM) 3236 Soy Protein Isolate.

Estrogenic Receptor-Functionalized Magnetite Nanoparticles for Rapid Separation of Phytoestrogens in Plant Extracts

With growing interests of phytoestrogens, many natural phytochemicals extracted from diverse plant species have been explored for their estrogenic-like activities and potential applications. In this work, a simple and rapid separation of phytoestrogenic compounds from crude plant extracts was purposed using magnetic nanoparticles (MNPs) of Fe₃O₄ immobilized with the ligand-binding domain (LBD) of estrogen receptor alpha (ERα). The recombinant LBD-ERα peptide of 40 kDa was produced and subsequently covalently linked to MNPs. One milligram of the LBD-ERα-immobilized MNPs demonstrated a specific binding to the standard 17β-estradiol (E2) of 3.37 nmol and 91.3-100 % of the bound E2 were subsequently recovered. LBD-ERα-immobilized MNPs could separate phytoestrogens of 4.6 nmol E2-equivalent activity from a 1-mg crude extract of Asparagus racemosus. The produced MNPs showed no separation yield when were applied to the negative controls, the crude extract of radish (Raphanus sativus), and the standard progesterone (P4). Thin-layer chromatography demonstrated a single phytochemical band of the separated phytoestrogens, which exhibited the activity to promote MCF-7 cell proliferation at 4.7 folds greater than the crude A. racemosus extract. The results of this work demonstrated a simple method to specifically separate phytoestrogens from crude plant extracts via the LBD-ERα-immobilized MNPs.

Analytical methods used to quantify isoflavones in cow's milk: a review

This paper provides an update and comprehensive review of the analytical methods used for quantifying isoflavones and their metabolites in cow’s milk. Isoflavones are secondary plant metabolites that are similar to 17 β-estradiol in chemical structure. They form one of the most common categories of phytoestrogens. Numerous health benefits have been attributed to isoflavones, but many of these compounds are also considered to be endocrine disruptors, with adverse effects on health. These contradictory trends offer an attractive prospect for future research, and therefore, sensitive and reliable analytical methods are required to clarify various issues about isoflavones. For this review, a structured methodology was used to select 26 relevant articles published between 2005 and 2015 from the Scopus and CAB Abstract databases. The review discusses individual steps of the analytical procedures described in these articles, including sample preparation, instrumental analysis and validation. The most commonly used analytical procedure is sample preparation involving liquid-liquid extraction and an enzymatic hydrolysis step followed by liquid chromatography with mass spectrometry analysis. Currently, however, there is no standardized procedure for the sample preparation and analysis of isoflavones in milk.

Negative ion electrospray high-resolution tandem mass spectrometry of polyphenols

Representative compounds with a 1,3-dihydroxybenzene substructure belonging to different important polyphenol classes (stilbenes, flavones, isoflavones, flavonols, flavanones, flavanols, phloroglucinols, anthraquinones and bisanthraquinones) were investigated based on detailed high-resolution tandem mass spectrometry measurements with an Orbitrap system under negative ion electrospray conditions. The mass spectral behaviour of these compound classes was compared among each other not only with respect to previously described losses of CO, CH2 CO and C3 O2 but also concerning the loss of CO2 and successive specific fragmentations. Furthermore, some unusual fragmentations such as the loss of a methyl radical during mass spectral decomposition are discussed. The obtained results demonstrate both similarities and differences in their mass spectral fragmentation under MS(n) conditions, allowing a characterization of the corresponding compound type. Copyright © 2015 John Wiley & Sons, Ltd.

A novel UHPLC method for the rapid and simultaneous determination of daidzein, genistein and equol in human urine

This work reports on a novel method involving reverse-phased ultra-high performance liquid chromatography (UHPLC) plus a spectrophotometric photodiode array/fluorescence (FLR) detection system for determining the concentration of equol and major soy isoflavones (daidzein and genistein) in human urine. The proposed method was validated in terms of its linearity, sensitivity, accuracy (recovery) and precision (intra- and inter-day repeatability). The isoflavone profiles of urine samples from a group of menopausal women following oral soy isoflavone supplementation were determined and compared. Screening for equol-producer status was accomplished with high sensitivity (detection limit of the FLR detector 2.93nM). The method involves a short chromatographic run time compared to conventional HPLC methods while allowing for the simultaneous and reliable quantification of daidzein, genistein and equol in human urine. It also allows for the rapid screening of multiple urine samples when testing for equol production status and checking patient adherence to isoflavone treatment regimens.

Determination of Isoflavone Content in SRM 3238 Using Liquid Chromatography-Particle Beam/Electron Ionization Mass Spectrometry

The characterization of marker components in botanical materials is a challenging task, and the increased consumption of botanicals and dietary supplements demands a greater understanding of the associated health benefits and risks. In order to successfully acquire and compare clinical results and correlate health trends, accurate, precise, and validated methods of analysis must be developed. Presented here is the development of a quantitative method for the determination of soy isoflavones (daidzin, glycitin, genistin, daidzein, and genistein) using LC-particle beam/electron ionization-MS (LC-PB/EIMS). An internal standard (IS) approach for quantitation with 7-hydroxy-4- chromone as the IS compound was used, with response factors for each individual isoflavone obtained from calibrant solutions. The results from this method were compared with the certified and reference values for National Institute of Standards and Technology (NIST) SRM 3238 Soy-Containing Solid Oral Dosage Form to demonstrate that the method was in control. Results obtained using LC-PB/EIMS were consistent with the NIST certified or reference values and their uncertainties for all five isoflavones, demonstrating that the LC-PB/EIMS approach is both accurate and precise when used for the determination of the target isoflavones in soy-containing dietary supplement finished products while simultaneously providing structural information.

Improving the estimation of flavonoid intake for study of health outcomes

Imprecision in estimating intakes of non-nutrient bioactive compounds such as flavonoids is a challenge in epidemiologic studies of health outcomes. The sources of this imprecision, using flavonoids as an example, include the variability of bioactive compounds in foods due to differences in growing conditions and processing, the challenges in laboratory quantification of flavonoids in foods, the incompleteness of flavonoid food composition tables, and the lack of adequate dietary assessment instruments. Steps to improve databases of bioactive compounds and to increase the accuracy and precision of the estimation of bioactive compound intakes in studies of health benefits and outcomes are suggested.

Isoflavones: chemistry, analysis, functions and effects on health and cancer

Isoflavones are phytoestrogens and natural plant compounds which are similar to 17-β-estradiol in chemical structure. It is known that they can act as estrogen agonists or antagonists, depending on endocrine estrogenic levels, but actions of isoflavones are rather complex due to large number of variables such as chemical structures and mechanisms. Some hypotheses on biological mechanisms have not satisfactorily been confirmed to date and human epidemiological and experimental studies have been relatively limited. Nevertheless, isoflavones and isoflavone rich foods have become a focus on interest due to positive health benefits on many diseases, especially prevention of hormone-related cancers, cardiovascular disease, osteoporosis, and adverse postmenopausal symptoms, and improvement of physiological condition such as maintaining cognitive function. This review provides an overview of chemistry, analytical techniques (focused on human biospecimens), functions including biological mechanisms, and effects of isoflavones, on the basis of the available meta-analysis and review articles and some original articles, on health and cancer.

Liquid chromatographic determination of polyphenenols in czech beers during brewing proces

High performance liquid chromatographic (HPLC/UV) method was adapted for simultaneous determination of seven polyphenols, including derivatives of benzoic (gallic and vanillic acids) and cinnamic acids (p-coumaric, ferulic and sinapic acids), flavan-3-ols (catechin) and flavonols (rutin) in worts and beers at the various stages of the brewing process. Based on the semi-quantitative HPLC analysis, total polyphenols chromatographic index (TPCI) was in the ranges of5.18 - 19.4 mg/L and 7.37 - 20.7 mg/L for all worts and beers, respectively. The HPLC analyses showed that relatively high levels of (+)-catechin and gallic acid were in all the worts and the beers, while the values were much lower for ferulic acid, rutin, vanillic acid, sinapic acid and p-coumaric acid. Polyphenols with relatively high concentrations, that were detected in all tested worts and beers, were gallic acid (1.29 - 4.75 mg/L resp. 2.59 - 4.97 mg/L), (+)-catechin (1.66 - 7.95 mg/L resp. 4.70 - 10.0 mg/L) and ferulic acid (0.41 - 4.53 mg/L resp. 1.05 - 2.87 mg/L). On the other side, the sinapic acid(0.72 - 1.59 mg/L resp. 0.72 - 2.5 mg/L), rutin (1.17 - 2.03 mg/L resp. 1.16 - 2.85 mg/L), p-coumaric acid(ND - 4.73 mg/L resp. ND - 1.44 mg/L) and vanillic acid (ND - 1.52 mg/L resp. 0.75 - 1.81 mg/L) were detected in lowest concentrations. In both, worts and beers investigated in this study, the changes in the contents of individual polyphenols were not uniform. In the case of some polyphenols, a decrease in the content was observed after boiling the worts with hops or after the main fermentation until maturation and filtration, but with some polyphenols, the concentrations were constant until the end of the process or even increased.

Improved high sensitivity analysis of polyphenols and their metabolites by nano-liquid chromatography-mass spectrometry

This study was conducted to assess the value of a high resolution, high mass accuracy time-of-flight analyzer in combination with nanoliquid chromatography for the analysis of polyphenols and their metabolites. The goal was to create a method that utilizes small volumes of biological fluids and provides a significant improvement in sensitivity compared with existing methods. Accordingly, nanoLC-MS and nanoLC-pseudo-multiple reaction monitoring (MRM) methods were developed that had a lower limit of quantification of 0.5 nM for several polyphenols and were linear over 2-3 orders of magnitude (R(2)>0.999). Using urine samples, the ability to observe and quantify polyphenols in such a complex biological fluid depended on much narrower mass windows (0.050 amu or less) on a TOF analyzer than those used on a quadrupole analyzer (0.7 amu). Although a greater selectivity was possible with the low mass resolution of a triple quadrupole instrument using the MRM approach, for the daidzein metabolite O-DMA, a chromatographically resolvable second peak could only be substantially reduced by using a 0.01 amu mass window. The advantage of a TOF analyzer for product ion data is that the whole MSMS spectrum is collected at high mass accuracy and MRM experiments are conducted in silico after the analysis.

Development of liquid chromatography-tandem mass spectrometry method for analysis of polyphenolic compounds in liquid samples of grape juice, green tea and coffee

A simple and fast method for the analysis of a wide range of polyphenolic compounds in juice, tea, and coffee samples was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was based on a simple sample preparation "dilute and shoot" approach, and LC-MS/MS quantification using genistein-d4 as an internal standard. The performance of six different syringeless filter devices was tested for sample preparation. The method was evaluated for recoveries of polyphenols at three spiking levels in juice, tea, and coffee samples. The recoveries of the majority of polyphenols were satisfactory (70-120%), but some varied significantly (20-138%) depending on the matrix. NIST Standard Reference Materials (SRM) 3257 Catechin Calibration Solutions and 3255 Camellia sinensis (Green Tea) Extract with certified concentrations of catechin and epicatechin were used for method validation. The measurement accuracy in two SRMs was 71-113%. The method was successfully applied to the analysis of liquid samples of grape juice, green tea, and coffee.

Anthocyanins in aged blueberry-fed rats are found centrally and may enhance memory

Research has shown that fruits and vegetables containing high levels of polyphenolics (flavonoids) display high total antioxidant activity. Our laboratory found that various fruit and vegetable extracts, particularly blueberry (BB), were effective in reversing age-related deficits in neuronal signaling and behavioral parameters following 8 weeks of feeding, possibly due to their polyphenolic content. However, it was unclear if these phytonutrients were able to directly access the brain from dietary BB supplementation (BBS). The present study examined whether different classes of polyphenols could be found in brain areas associated with cognitive performance following BBS. Thus, 19 month old F344 rats were fed a control or 2% BB diet for 8-10 weeks and tested in the Morris water maze (MWM), a measure of spatial learning and memory. LC-MS analyses of anthocyanins in the diet and subsequently in different brain regions of BBS and control rats were carried out. Several anthocyanins (cyanidin-3-O-beta-galactoside, cyanidin-3-O-beta-glucoside, cyanidin-3-O-beta-arabinose, malvidin-3-O-beta-galactoside, malvidin-3-O-beta-glucoside, malvidin-3-O-beta-arabinose, peonidin-3-O-beta-arabinose and delphinidin-3-O-beta-galactoside) were found in the cerebellum, cortex, hippocampus or striatum of the BBS rats, but not the controls. These findings are the first to suggest that polyphenolic compounds are able to cross the blood brain barrier and localize in various brain regions important for learning and memory. Correlational analyses revealed a relationship between MWM performance in BBS rats and the total number of anthocyanin compounds found in the cortex. These findings suggest that these compounds may deliver their antioxidant and signaling modifying capabilities centrally.

Analytical strategies based on chromatography-mass spectrometry for the determination of estrogen-mimicking compounds in food

Food safety can be compromised by the presence of a wide variety of substances, deriving from both natural and anthropogenic sources. Among these substances, compounds exhibiting various degrees of estrogenic activity have been widely studied in environmental samples, whereas less attention has been devoted to food matrices. The aim of the present review is to give a general overview on the recent analytical methods based on gas or liquid chromatography coupled to mass spectrometry for the determination of estrogen-like compounds in foods, including new developments, improvements and upcoming trends in the field. Attention will be focused on four representative groups of compounds, i.e. natural and synthetic estrogens, mycoestrogens, phytoestrogens, and alkylphenols.

The metabolism and analysis of isoflavones and other dietary polyphenols in foods and biological systems

Polyphenols in dietary and botanical matrices are usually present as simple and complex O-glycosides. In fermented dietary materials, the glycosidic moiety is removed and accompanied in some cases by more complex changes to the polyphenol. As for most xenobiotics, polyphenols undergo phase II conjugation in the intestinal wall during their absorption from the gut. In contrast, a few polyphenols, such as puerarin in the kudzu vine, are C-glycosides and are stable in the gut and during absorption, distribution and excretion. Large bowel bacteria reduce polyphenol aglycones, causing opening of the heterocyclic B-ring and ring cleavage. The products are mostly absorbed and enter the bloodstream. Phase I and II metabolism events occur in the intestine and the liver - most polyphenols predominantly circulate as β-glucuronides and sulfate esters with very little as the aglycones, the presumed active forms. In addition, metabolism can occur in non-hepatic tissues and cells including breast tumor cells that have variable amounts of cytochrome P450s, sulfatase and sulfotransferase activities. Inflammatory cells produce chemical oxidants (HOCl, HOBr, ONO(2)(-)) that will react with polyphenols. The isoflavones daidzein and genistein and the flavonol quercetin form mono- and dichlorinated products in reaction with HOCl. Genistein is converted to 3'-nitrogenistein in the lung tissue of lipopolysaccharide-treated rats. Whereas polyphenols that can be converted to quinones or epoxides react with glutathione (GSH) to form adducts, chlorinated isoflavones do not react with GSH; instead, they are converted to β-glucuronides and are excreted in bile. Analysis of polyphenols and their metabolites is routinely carried out with great sensitivity, specificity and quantification by LC-tandem mass spectrometry. Critical questions about the absorption and tissue uptake of complex polyphenols such as the proanthocyanins can be answered by labeling these polyphenols with (14)C-sucrose in plant cell culture and then purifying them for use in animal experiments. The (14)C signature is quantified using accelerator mass spectrometry, a technique capable of detecting one (14)C atom in 10(15) carbon atoms. This permits the study of the penetration of the polyphenols into the interstitial fluid, the fluid that is actually in contact with non-vascular cells.

Characterization of isoflavone composition in soy-based nutritional supplements via ultra performance liquid chromatography

The specific isoflavone composition of nutritional supplements is commonly not-labeled, although the stated amounts are strongly dependent on the present isoflavone conjugates. Hence, 11 soy-based dietary supplements were characterized via a newly established ultra performance liquid chromatography (UPLC) method, on both their native conjugated isoflavone spectra, as well as on quantitative amounts derived as total aglycones after enzymatic hydrolysis utilizing Helix pomatia juice. Capitalizing on sub-2 microm particles, the established RP-UPLC technique facilitated efficient chromatographic separation of all 12 soy intrinsic isoflavone forms within 10 min. Derived native isoflavone profiles implied a certain variability, comprising conjugated forms, especially glycosides, as the predominant isoflavonic constituents throughout the majority of supplements, whereas only two samples indicated the more bioavailable free aglycones as prevailing compounds. Moreover, the robust quantification as total aglycones subsequent to enzymatic hydrolysis, unexceptionally yielded negative deviations referring to the labeled specifications, thus implying that stated amounts were typically calculated on basis of the high molecular isoflavone conjugates. Thus, especially in regard to better comparability, regulations concerning an uniform labeling basis are needed.

Guidance from an NIH workshop on designing, implementing, and reporting clinical studies of soy interventions

The NIH sponsored a scientific workshop, "Soy Protein/Isoflavone Research: Challenges in Designing and Evaluating Intervention Studies," July 28-29, 2009. The workshop goal was to provide guidance for the next generation of soy protein/isoflavone human research. Session topics included population exposure to soy; the variability of the human response to soy; product composition; methods, tools, and resources available to estimate exposure and protocol adherence; and analytical methods to assess soy in foods and supplements and analytes in biologic fluids and other tissues. The intent of the workshop was to address the quality of soy studies, not the efficacy or safety of soy. Prior NIH workshops and an evidence-based review questioned the quality of data from human soy studies. If clinical studies are pursued, investigators need to ensure that the experimental designs are optimal and the studies properly executed. The workshop participants identified methodological issues that may confound study results and interpretation. Scientifically sound and useful options for dealing with these issues were discussed. The resulting guidance is presented in this document with a brief rationale. The guidance is specific to soy clinical research and does not address nonsoy-related factors that should also be considered in designing and reporting clinical studies. This guidance may be used by investigators, journal editors, study sponsors, and protocol reviewers for a variety of purposes, including designing and implementing trials, reporting results, and interpreting published epidemiological and clinical studies.

Development of a high-throughput LC/APCI-MS method for the determination of thirteen phytoestrogens including gut microbial metabolites in human urine and serum

The investigation into the potential usefulness of phytoestrogens in the treatment of menopausal symptoms requires large-scale clinical trials that involve rapid, validated assays for the characterization and quantification of the phytoestrogenic precursors and their metabolites in biological matrices, as large interindividual differences in metabolism and bioavailability have been reported. Consequently, a new sensitive high-performance liquid chromatography-mass spectrometry method (HPLC-MS) for the quantitative determination of thirteen phytoestrogens including their most important gut microbial metabolites (genistein, daidzein, equol, dihydrodaidzein, O-desmethylangolensin, coumestrol, secoisolariciresinol, matairesinol, enterodiol, enterolactone, isoxanthohumol, xanthohumol and 8-prenylnaringenin) in human urine and serum within one single analytical run was developed. The method uses a simple sample preparation procedure consisting of enzymatic deconjugation followed by liquid-liquid extraction (LLE) or solid-phase extraction (SPE) for urine or serum, respectively. The phytoestrogens and their metabolites are detected with a single quadrupole mass spectrometer using atmospheric pressure chemical ionization (APCI), operating both in the positive and the negative mode. This bioanalytical method has been fully validated and proved to allow an accurate and precise quantification of the targeted phytoestrogens and their metabolites covering the lower parts-per-billion range for the measurement of relevant urine and serum levels following ingestion of phytoestrogen-rich dietary supplements.

Analytical and compositional aspects of isoflavones in food and their biological effects

This paper provides an overview of analytical techniques used to determine isoflavones (IFs) in foods and biological fluids with main emphasis on sample preparation methods. Factors influencing the content of IFs in food including processing and natural variability are summarized and an insight into IF databases is given. Comparisons of dietary intake of IFs in Asian and Western populations, in special subgroups like vegetarians, vegans, and infants are made and our knowledge on their absorption, distribution, metabolism, and excretion by the human body is presented. The influences of the gut microflora, age, gender, background diet, food matrix, and the chemical nature of the IFs on the metabolism of IFs are described. Potential mechanisms by which IFs may exert their actions are reviewed, and genetic polymorphism as determinants of biological response to soy IFs is discussed. The effects of IFs on a range of health outcomes including atherosclerosis, breast, intestinal, and prostate cancers, menopausal symptoms, bone health, and cognition are reviewed on the basis of the available in vitro, in vivo animal and human data.

Bioactivity of Grape Chemicals for Human Health

Grapevine ( Vitis vinifera) products, grape and grape juice, represent a valuable source of bioactive phytochemicals, synthesized by three secondary metabolic pathways (phenylpropanoid, isoprenoid and alkaloid biosynthetic routes) and stored in different plant tissues. In the last decades, compelling evidence suggested that regular consumption of these products may contribute to reducing the incidence of chronic illnesses, such as cancer, cardiovascular diseases, ischemic stroke, neurodegenerative disorders and aging, in a context of the Mediterranean dietary tradition. The health benefits arising from grape product intake can be ascribed to the potpourri of biologically active chemicals occurring in grapes. Among them, the recently discovered presence of melatonin adds a new element to the already complex grape chemistry. Melatonin, and its possible synergistic action with the great variety of polyphenols, contributes to further explaining the observed health benefits associated with regular grape product consumption.

Screening and confirmatory methods for the analysis of macrocyclic lactone mycotoxins by CE with amperometric detection

A simple analytical scheme for the screening and quantification of zearalenone and its metabolites, alpha-zearalenol and beta-zearalenol, is reported. Extracts from maize flour samples were collected by supercritical fluid extraction and afterwards, they were analyzed by CE with amperometric detection. This scheme allowed a rapid and reliable identification of contaminated flour samples according to the reference value established for zearalenone by directive 2005/38/EC (200 microg/kg). The sample screening method was carried out by CZE using 25 mM borate separation buffer at pH 9.2 and 25.0 kV as separation voltage, monitoring the amperometric signal at +700 mV with a carbon paste electrode. In this way, total amount of mycotoxins was determined and samples were processed in 4 min with a detection limit of 12 microg/L, enough to discriminate between positive (more than 200 microg/L total mycotoxins) and negative samples (less than 200 microg/L total mycotoxins). Positive samples were then subjected to CZE separation and quantification of each analyte was done with 50 mM borate running buffer modified with 30% methanol at pH 9.7 and 17.5 kV as separation voltage. Under these conditions, separation was achieved in 15 min with detection limits from 20 to 35 microg/L for each analyte.

Determination of phytoestrogens in dietary supplements by LC-MS/MS

Labelling data quantifying the exact content of individual phytoestrogen analytes in dietary supplements are generally poor. As these products are commonly used in the management of menopause symptoms, any clinical benefits would be dependent on the exact dosage of isoflavones received. Well-established extraction procedures and updated isotope dilution mass spectrometry liquid chromatography coupled with tandem mass spectrometry detection (LC-MS/MS) have been used to accurately quantify the concentrations of ten common isoflavones in 35 dietary supplement samples on sale in the UK, Canada and Italy. Concentration-specific ionization suppression is described for biochanin A and formononetin. All supplements contained phytoestrogens. The soya isoflavones (genistein, daidzein, glycitein) were present in all products and the majority also contained the red clover isoflavones (biochanin A, formononetin) and some the Kudzu isoflavones (daidzein, puerarin). The content of total isoflavones per dose ranged from <1 to 53 mg. Trace amounts of coumestrol were found in six products. Other less common analytes, the prenylnaringenins (6-prenylnaringenin, 8-prenylnaringenin, 6,8-diprenylnaringenin) were not found in any of the products. Only 14 of 35 supplements were found to deliver more than or equal to 40 mg day(-1) of aglycone isoflavones, a consensus dose value recognized as delivering therapeutic benefit. Eleven did not match label claims. Six delivered less than 10 mg day (-1) of isoflavones. There has been little improvement in the overall quality of industry labelling in the five years since this was last investigated. Consequently, the public, retailers and healthcare professionals should consider using standardized isoflavone supplements, which are supported by analytical measurements.

Determination of urinary phytoestrogens by HPLC-MS/MS: a comparison of atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI)

A comparison of the analytical performance of atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) for the quantitative determination of six urinary phytoestrogens (daidzein, O-desmethylangolensin, equol, enterodiol, enterolactone and genistein) by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) is presented here. Both APCI and ESI were suitable for the analysis of these compounds; however, ESI did improve measurement imprecision and sensitivity in certain cases. Method imprecision (between-run coefficients of variation [CVs] from duplicate analysis of three quality control [QC] urine pools across 20 runs) was 5.6-12% for ESI, as opposed to 5.3-30% for APCI. At low concentrations (3-60 ng/mL, analyte dependent) imprecision was lower with ESI, whereas both techniques were generally commensurate at high concentrations (200-1000 ng/mL, analyte dependent). Method accuracy (spiked analyte recovery from the QC pools) was comparable between techniques: 86-114% for ESI; 95-105% for APCI. Limits of detection (LODs) were equivalent or better with ESI compared to APCI, with the most significant LOD improvement observed for equol (ESI: 0.3 ng/mL; APCI: 2.7 ng/mL). This translated into a substantial increase in equol detection frequency (% of sample results above LOD) within a random patient sample subset (98% for ESI, compared to 81% for APCI, n=378). Correlation (Pearson) and agreement (Deming regression, Bland-Altman bias) between ESI and APCI results in the patient subset was better in cases where imprecision and sensitivity was similar for both techniques (daidzein, enterolactone, genistein: r=0.993-0.998; slope=0.98-1.03; bias=-4.2 to -0.8%); correlation and/or agreement was poorer for analytes, where APCI imprecision and sensitivity were inferior (equol, O-desmethylangolensin, enterodiol). Baring significant factors arising from differences in ionization source design, these observations suggest that ESI is more appropriate for urinary biomonitoring of these compounds by LC-MS/MS.

Seasonal variations in the isoflavonoids of radix Puerariae

The variations in isoflavonoid content in Radix Puerariae, the root of Pueraria lobata (Wild) Ohwi, have been examined in order to determine the optimum time to harvest the herb. Total isoflavonoid contents have been analysed by a UV spectrophotometric method whilst HPLC with photodiode array detection has been used to monitor the contents of seven major individual isoflavonoids, namely, 3'-hydroxypuerarin, puerarin, 3'-methoxypuerarin, daidzin, genistin, formononetin-7-glucoside and daidzein. Ninety-six samples of Radix Puerariae of different ages and harvested in different months were collected and analysed. The results clearly showed that 3-year-old roots harvested in January have the highest yields of isoflavonoid compounds. Moreover, the results obtained by both methods have a strong correlation. This suggested that the simple and fast UV spectrophotometric method could be used for monitoring the phytochemical quality of Radix Puerariae.

Recent studies on selected botanical dietary supplement ingredients

The market for botanical dietary supplements in the US has grown rapidly during the last 15 years. Use of newly introduced botanical ingredients has often outpaced an adequate scientific understanding of the ingredients themselves. This may lead to problems, including misidentification, mislabeling, adulteration, and toxicity related to the intended ingredient or one substituted for it. This article reviews recent work with several botanical ingredients (Ephedra, Citrus species, Hoodia gordonii, Teucrium, isoflavones) that illustrates the complexity of the current situation and approaches that contribute to ensuring the quality of botanical ingredients. Recent work with contamination of botanical products by mycotoxins is also reviewed. The need for tools for botanical authentication and methods for reproducible extraction of bioactive constituents is critical. Such tools, and improved analytical techniques for identifying potentially bioactive constituents in fresh plant material and in concentrated extracts and for detection of hazardous contaminants, are expected to improve the overall quality and safety of botanical dietary supplement ingredients.