Phytoestrogens, cancer and coronary heart disease

The Austrian children's biomonitoring survey 2020 Part B: Mycotoxins, phytotoxins, phytoestrogens and food processing contaminants

This study assessed the levels of environment and food-related exposures in urine of Austrian school children aged six to ten (n = 85) focusing on mycotoxins, phytoestrogens, and food processing by-products using two multi-analyte LC-MS/MS methods. Out of the 55 biomarkers of exposure reported in this study, 22 were quantified in the first void urine samples. Mycotoxins frequently quantified included zearalenone (detection rate 100%; median 0.11 ng/mL), deoxynivalenol (99%; 15 ng/mL), alternariol monomethyl ether (75%; 0.04 ng/mL), and ochratoxin A (19%; 0.03 ng/mL). Several phytoestrogens, including genistein, daidzein, and its metabolite equol, were detected in all samples at median concentrations of 22 ng/mL, 43 ng/mL, and 14 ng/mL, respectively. The food processing by-product 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), was detected in 4% of the samples (median 0.016 ng/mL). None of the investigated samples contained the tested phytotoxins that were rarely considered for human biomonitoring previously (pyrrolizidine alkaloids, tropane alkaloids, aristolochic acids). When relating estimated exposure to current health-based guidance values, 22% of the children exceeded the tolerable daily intake for deoxynivalenol, and the estimated MOE for OTA indicates possible health risks for some children. The results clearly demonstrate frequent low-level (co-)exposure and warrant further exposome-scale exposure assessments, especially in susceptible sub-populations and longitudinal settings.

Carcinogenic and non-carcinogenic risk assessment induced by pesticide residues in fresh pistachio in Iran based on Monte Carlo simulation

This research is aimed at the analysis of 87 pesticides in 30 fresh pistachio samples prepared from stores in Iran by QuEChERS-ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The results showed at least one pesticide was in 67% of fresh pistachio samples. Kresoxim methyl residue was detected in 20 samples with average of 0.11 mg kg^-1; this average is 2.2 times more than maximum residue limit (MRL). Buprofezin was recognized in five samples with average of 0.17 mg kg^-1 was observed with 3.4 times more than MRL; hexaconazole and permethrin were recognized in three samples lower than MRL with an average residue of 0.030 and 0.028 mg kg^-1, respectively. In addition, potential non-carcinogenic and carcinogenic health risk assessments were evaluated using probabilistic methods performed with the Monte Carlo simulation algorithm. The order of pesticide ranking based on hazard quotient (HQ) was hexaconazole > buprofezin > permethrin > kresoxim methyl. Total HQ (HI) was 2.0E-4 and for children, 9.0E-4. Hence, it means fresh pistachio consuming maybe not have significant short-term health risks for consumer. Ranking based on cancer risk (CR) was hexaconazole > kresoxim methyl > metalaxyl > permethrin > buprofezin. However, total CR due to pesticide residues was not higher than 1E-6 value (1.09E-9); therefore, consumers were not at significant risk of carcinogenicity in this product.

Molecular signaling mechanisms behind polyphenol-induced bone anabolism

For millennia, in the different cultures all over the world, plants have been extensively used as a source of therapeutic agents with wide-ranging medicinal applications, thus becoming part of a rational clinical and pharmacological investigation over the years. As bioactive molecules, plant-derived polyphenols have been demonstrated to exert many effects on human health by acting on different biological systems, thus their therapeutic potential would represent a novel approach on which natural product-based drug discovery and development could be based in the future. Many reports have provided evidence for the benefits derived from the dietary supplementation of polyphenols in the prevention and treatment of osteoporosis. Polyphenols are able to protect the bone, thanks to their antioxidant properties, as well as their anti-inflammatory actions by involving diverse signaling pathways, thus leading to bone anabolic effects and decreased bone resorption. This review is meant to summarize the research works performed so far, by elucidating the molecular mechanisms of action of polyphenols in a bone regeneration context, aiming at a better understanding of a possible application in the development of medical devices for bone tissue regeneration.

Skin aging and oxidative stress: Equol's anti-aging effects via biochemical and molecular mechanisms

Oxygen in biology is essential for life. It comes at a cost during normal cellular function, where reactive oxygen species (ROS) are generated by oxidative metabolism. Human skin exposed to solar ultra-violet radiation (UVR) dramatically increases ROS production/oxidative stress. It is important to understand the characteristics of human skin and how chronological (intrinsic) aging and photo-aging (extrinsic aging) occur via the impact of ROS production by cascade signaling pathways. The goal is to oppose or neutralize ROS insults to maintain good dermal health. Botanicals, as active ingredients, represent one of the largest categories used in dermatology and cosmeceuticals to combat skin aging. An emerging botanical is equol, a polyphenolic/isoflavonoid molecule found in plants and food products and via gastrointestinal metabolism from precursor compounds. Introductory sections cover oxygen, free radicals (ROS), oxidative stress, antioxidants, human skin aging, cellular/molecular ROS events in skin, steroid enzymes/receptors/hormonal actions and genetic factors in aging skin. The main focus of this review covers the characteristics of equol (phytoestrogenic, antioxidant and enhancement of extracellular matrix properties) to reduce skin aging along with its anti-aging skin influences via reducing oxidative stress cascade events by a variety of biochemical/molecular actions and mechanisms to enhance human dermal health.

Dietary isoflavones and bone mineral density during midlife and the menopausal transition: cross-sectional and longitudinal results from the Study of Women's Health Across the Nation Phytoestrogen Study

OBJECTIVE

This study aims to examine cross-sectional and longitudinal relations between dietary intake of isoflavones and bone mineral density (BMD) at the lumbar spine (LS) and femoral neck (FN) in black, white, Chinese, and Japanese women during the menopausal transition.

METHODS

We tested whether tertiles of isoflavone intake were associated with baseline BMD when all women were premenopausal or early perimenopausal. To analyze whether isoflavone intake was associated with longitudinal BMD, we fitted piecewise linear models to repeated measurements of baseline-normalized LS or FN BMD as functions of time before or after the final menstrual period (FMP) date.

RESULTS

Multiply adjusted mean FN BMD values of premenopausal Japanese women were monotonically positively related to isoflavone consumption (P for trend = 0.0003). Otherwise, no statistically significant baseline associations were observed. During the period of 1 year before the FMP through 5 years after the FMP, all participants lost LS and FN BMD. Loss was unrelated to isoflavone intake, except for Japanese women during the period of 1 year before the FMP to 2 years after the FMP: higher tertiles of isoflavone intake were associated with greater annual LS BMD loss rates (P for trend = 0.01) and FN loss rates (P for trend = 0.04).

CONCLUSIONS

In Japanese women, higher isoflavone intake is associated with higher peak FN BMD but also with greater rates of LS and FN BMD loss during the menopausal transition. Results for the other racial/ethnic groups did not support a relation between dietary intake of isoflavones and either peak BMD or BMD loss during the menopausal transition.

Urinary enterolactone is associated with obesity and metabolic alteration in men in the US National Health and Nutrition Examination Survey 2001-10

Phyto-oestrogens are a family of plant-derived xeno-oestrogens that have been shown to prevent cancer in some studies. Whether phyto-oestrogen intake affects obesity status in a population is still unclear. In the present cross-sectional study, we examined the association of urinary phyto-oestrogen metabolites with obesity and metabolic parameters in children and adults. Data from 1294 children (age 6-19 years) and from 3661 adults (age ≥ 20 years) who participated in the US National Health and Nutrition Examination Survey 2001-10 were analysed. Multivariate logistic regression was applied to investigate the associations of BMI, waist circumference, serum metabolites (total cholesterol, HDL-cholesterol, LDL-cholesterol, TAG, fasting glucose and fasting insulin) and the metabolic syndrome with urinary phyto-oestrogen levels. When stratified by age and sex, we found a stronger association (OR 0·30, 95 % CI 0·17, 0·54; P< 0·001) between urinary enterolactone levels and obesity in adult males (age 20-60 years) than in children (age 12-19 years) or the elderly (age >60 years) in the same survey. However, no associations with urinary daidzein, O-desmethylangolensin, equol, enterodiol or genistein were found in the overall population. We also found that the elevation of enterolactone levels was inversely associated with TAG levels, fasting glucose levels, fasting insulin levels and the metabolic syndrome in males aged 20-60 years, but positively associated with HDL-cholesterol levels. The present results provide epidemiological evidence that urinary enterolactone is inversely associated with obesity in adult males.

Histological investigation of the effect of soybean (Glycine max) extracts on the collagen layer and estrogen receptors in the skin of female rats

OBJECTIVES

The purpose of this study was to analyze the effects of soybean extracts obtained using different extraction methods on the skin of female rats.

METHOD

A total of 64 female Sprague-Dawley rats were divided into 8 equal groups. Various extracts were administered to the female rats by oral gavage for one month. The groups comprised carboxymethyl cellulose-free control, carboxymethyl cellulose-plus control, 100-mg/kg n-hexane extract, 200-mg/kg n-hexane extract, 100-mg/kg ethyl acetate extract, 200-mg/kg ethyl acetate extract, 100-mg/kg ethanol extract and 200-mg/kg ethanol extract groups. The thickness of the collagen layer and the number of estrogen receptor-positive cells were evaluated.

RESULTS

All the extract-treated groups showed a statistically significant decrease in the number of estrogen receptor-positive cells compared with the control groups. Regarding the thickness of the collagen layer, only the 200-mg/kg ethyl acetate extract-treated group showed a significant increase compared with the control groups (p<0.05).

CONCLUSIONS

Our data suggest that oral intake of three different total soybean extracts might have positive estrogenic effects on the skin and that only a high-dose ethyl acetate extract can increase the expression of collagen, which may prove to be beneficial for postmenopausal facial skin.

Neoplasia and neoplasm-associated lesions in laboratory colonies of zebrafish emphasizing key influences of diet and aquaculture system design

During the past decade, the zebrafish has emerged as a leading model for mechanistic cancer research because of its sophisticated genetic and genomic resources, its tractability for tissue targeting of transgene expression, its efficiency for forward genetic approaches to cancer model development, and its cost effectiveness for enhancer and suppressor screens once a cancer model is established. However, in contrast with other laboratory animal species widely used as cancer models, much basic cancer biology information is lacking in zebrafish. As yet, data are not published regarding dietary influences on neoplasm incidences in zebrafish. Little information is available regarding spontaneous tumor incidences or histologic types in wild-type lines of zebrafish. So far, a comprehensive database documenting the full spectrum of neoplasia in various organ systems and tissues is not available for zebrafish as it is for other intensely studied laboratory animal species. This article confirms that, as in other species, diet and husbandry can profoundly influence tumor incidences and histologic spectra in zebrafish. We show that in many laboratory colonies wild-type lines of zebrafish exhibit elevated neoplasm incidences and neoplasm-associated lesions such as heptocyte megalocytosis. We present experimental evidence showing that certain diet and water management regimens can result in high incidences of neoplasia and neoplasm-associated lesions. We document the wide array of benign and malignant neoplasms affecting nearly every organ, tissue, and cell type in zebrafish, in some cases as a spontaneous aging change, and in other cases due to carcinogen treatment or genetic manipulation.

Dietary flavonol intake is associated with age of puberty in a longitudinal cohort of girls

Lignans and flavonols are dietary phytoestrogens found at high concentrations in the Western Diet. They have potential to influence the timing of puberty. We hypothesized that greater consumption of these 2 phytoestrogens would be related to later age at pubertal onset among girls. Pubertal assessment and 24-hour diet recall data were available for 1178 girls, ages 6 to 8 years (mean 7.3 years) in the Breast Cancer and Environment Research Project Puberty Study. Lignan and flavonol intakes were mainly derived from fruit and vegetable consumption. Average consumption was 6.5 mg/d for flavonols and 0.6 mg/d for lignans. Highest flavonol consumption (>5 mg/d) was associated with later breast development (adjusted hazards ratio [HR]: 0.74, 95% CI: [0.61-0.91]) compared to 2 to 5 mg/d (adjusted HR: 0.84, 95% CI: [0.70-1.0]) and <2 mg/d (referent group; P-trend = .006). Flavonol intake was not associated with pubic hair development. Lignan intake was not associated with either breast or pubic hair development. Dietary intake was only weakly correlated with urinary enterolactone, a biomarker for lignans (RS = 0.13). Consistent with biologic properties of phytoestrogens that indicate hormonal activity, their consumption may be associated with reproductive end points, even in childhood.

Antioxidant Activity of the Isoflavonoids from the Roots of Maackia amurensis

Seven isoflavonoids, including a new glycoside, (6a R,11a R)-medicarpin-3- O-gentiobioside (6), were isolated from the roots of Maackia amurensis using repeated column chromatography on a Toyopearl HW-50F sorbent and identified by HPLC–PDA–MS, 1H NMR, 13C, 1H–1H COSY, HSQC NMR and HMBC NMR analyses as daidzin (1), genistein-7- O-gentiobioside (2), pseudobaptigenin-7- O-gentiobioside (3), formononetin-7- O-gentiobioside (4), (6a R,11a R)-maackiain-3- O-gentiobioside (5), and 5- O-methylgenistein-7- O-gentiobioside (7). In the model of oxidative stress induced by formalin injection, the isolated isoflavone and pterocarpan glucosides 1-7 were shown to reduce the formation of malondialdehyde (MDA) and other thiobarbituric acid reactive substances (TBARS), as well as glutathione peroxidase (GPO) activity in rats.

Tools to evaluate estrogenic potency of dietary phytoestrogens:A consensus paper from the EU Thematic Network "Phytohealth" (QLKI-2002-2453)

Phytoestrogens are naturally occurring plantderived polyphenols with estrogenic potency. They are ubiquitous in diet and therefore, generally consumed. Among Europeans, the diet is rich in multiple putative phytoestrogens including flavonoids, tannins, stilbenoids, and lignans. These compounds have been suggested to provide beneficial effects on multiple menopause-related conditions as well as on development of hormone-dependent cancers, which has increased the interest in products and foods with high phytoestrogen content. However, phytoestrogens may as well have adverse estrogenicity related effects similar to any estrogen. Therefore, the assessment of estrogenic potency of dietary compounds is of critical importance. Due to the complex nature of estrogenicity, no single comprehensive test approach is available. Instead, several in vitro and in vivo assays are applied to evaluate estrogenic potency. In vitro estrogen receptor (ER) binding assays provide information on the ability of the compound to I) interact with ERs, II) bind to estrogen responsive element on promoter of the target gene as ligand-ER complex, and III) interact between the co-activator and ERs in ligand-dependent manner. In addition, transactivation assays in cells screen for ligand-induced ERmediated gene activation. Biochemical in vitro analysis can be used to test for possible effects on protein activities and E-screen assays to measure (anti)proliferative response in estrogen responsive cells. However, for assessment of estrogenicity in organs and tissues, in vivo approaches are essential. In females, the uterotrophic assay is applicable for testing ERa agonistic and antagonistic dietary compounds in immature or adult ovariectomized animals. In addition, mammary gland targeted estrogenicity can be detected as stimulated ductal elongation and altered formation of terminal end buds in immature or peripubertal animals. In males, Hershberger assay in peri-pubertal castrated rats can be used to detect (anti)androgenic/ (anti)estrogenic responses in accessory sex glands and other hormone regulated tissues. In addition to these short-term assays, sub-acute and chronic reproductive toxicity assays as well as two-generation studies can be applied for phytoestrogens to confirm their safety in long-term use. For reliable assessment of estrogenicity of dietary phytoestrogens in vivo, special emphasis should be focused on selection of the basal diet, route and doses of administration, and possible metabolic differences between the species used and humans. In conclusion, further development and standardization of the estrogenicity test methods are needed for better interpretation of both the potential benefits and risks of increasing consumption of phytoestrogens from diets and supplements.

Urinary enterolignan concentrations are positively associated with serum HDL cholesterol and negatively associated with serum triglycerides in U.S. adults

Fiber-rich diets are associated with favorable lipid profiles, but the specific compounds and the mechanisms behind this effect are yet to be fully understood. Lignans are fiber-related polyphenols that have been associated with lower prevalence of cardiovascular disease. The objective of this study was to investigate the relationship between dietary lignan exposure, measured as the urinary concentration of their metabolites, enterolactone and enterodiol, and serum lipids in a representative sample of U.S. adults. We carried out a cross-sectional analysis of data from 1492 adults who participated in the 1999-2004 NHANES. The mean urinary concentration of enterolignans in U.S. adults was 1.9 μmol/L. The multivariate-adjusted mean differences comparing the highest and lowest enterolignan tertile were 0.06 mmol/L for HDL cholesterol and -0.17 mmol/L for TG (P < 0.05). In spline regression models, we also found an inverse association between serum TG and urinary enterolignan concentrations. Serum HDL cholesterol levels increased linearly with increasing enterolignan concentrations. Modest or no associations were found between enterolignan concentrations and serum LDL cholesterol or total cholesterol. In conclusion, enterolignan concentrations are associated with lower serum TG concentrations and greater HDL cholesterol concentrations in U.S. adults.

Development of an updated phytoestrogen database for use with the SWAN food frequency questionnaire: intakes and food sources in a community-based, multiethnic cohort study

Phytoestrogens, heterocyclic phenols found in plants, may benefit several health outcomes. However, epidemiologic studies of the health effects of dietary phytoestrogens have yielded mixed results, in part due to challenges inherent in estimating dietary intakes. The goal of this study was to improve the estimates of dietary phytoestrogen consumption using a modified Block Food Frequency Questionnaire (FFQ), a 137-item FFQ created for the Study of Women's Health Across the Nation (SWAN) in 1994. To expand the database of sources from which phytonutrient intakes were computed, we conducted a comprehensive PubMed/Medline search covering January 1994 through September 2008. The expanded database included 4 isoflavones, coumestrol, and 4 lignans. The new database estimated isoflavone content of 105 food items (76.6%) vs. 14 (10.2%) in the 1994 version and computed coumestrol content of 52 food items (38.0%), compared to 1 (0.7%) in the original version. Newly added were lignans; values for 104 FFQ food items (75.9%) were calculated. In addition, we report here the phytonutrient intakes for each racial and language group in the SWAN sample and present major food sources from which the phytonutrients came. This enhanced ascertainment of phytoestrogens will permit improved studies of their health effects.

Biochemical investigation and gene analysis of equol: a plant and soy-derived isoflavonoid with antiaging and antioxidant properties with potential human skin applications

The purpose of this study was to investigate the effects of equol, a plant and intestinal flora derived isoflavonoid molecule on the expression of skin genes and proteins using human dermal models. As equol has been shown to mimic 17β-estradiol and bind specifically to 5α-dihydrotestostone (5α-DHT), these agents were used (in addition to equol) to determine whether equol may play important and beneficial roles in the extracellular matrix (ECM). Equol at 0.3 or 1.2% in qPCR experiments using a human skin barrier model examined ECM gene expression. Equol, 5α-DHT, and 17β-estradiol at 10 nM were studied in human monolayer fibroblasts cultures (hMFC) for ECM protein expression. Human fibroblast three-dimensional organotypic cultures revealed equol's influence (@ 10 nM) on ECM proteins via fluorescent-activated cell sorting (FACS) analysis. In qPCR experiments, equol significantly increased collagen, elastin (ELN), and tissue inhibitor of metalloprotease and decreased metalloproteinases (MMPs) gene expression and caused significant positive changes in skin antioxidant and antiaging genes. In hMFC, equol significantly increased collagen type I (COL1A1), whereas, 5α-DHT significantly decreased cell viability that was blocked by equol. FACS analysis showed equol and 17β-estradiol significantly stimulated COL1A1, collagen type III (COL3A1), and ELN while MMPs were significantly decreased compared with control values. Finally, tamoxifen blocked the positive influences of equol on ECM proteins via FACS analysis. These findings suggest that equol has the potential to be used topically for the treatment and prevention of skin aging, by enhancing ECM components in human skin.

Nutrition and human health from a sex-gender perspective

Nutrition exerts a life-long impact on human health, and the interaction between nutrition and health has been known for centuries. The recent literature has suggested that nutrition could differently influence the health of male and female individuals. Until the last decade of the 20th century, research on women has been neglected, and the results obtained in men have been directly translated to women in both the medicine and nutrition fields. Consequently, most modern guidelines are based on studies predominantly conducted on men. However, there are many sex-gender differences that are the result of multifactorial inputs, including gene repertoires, sex steroid hormones, and environmental factors (e.g., food components). The effects of these different inputs in male and female physiology will be different in different periods of ontogenetic development as well as during pregnancy and the ovarian cycle in females, which are also age dependent. As a result, different strategies have evolved to maintain male and female body homeostasis, which, in turn, implies that there are important differences in the bioavailability, metabolism, distribution, and elimination of foods and beverages in males and females. This article will review some of these differences underlying the impact of food components on the risk of developing diseases from a sex-gender perspective.

Effectiveness of phytoestrogens in climacteric medicine

The increased interest in phytoestrogens in the management of menopausal symptoms followed the publication of the Women's Health Initiative study. A wide-spread perception that these plant-derived compounds are equivalent to estrogen was established. These compounds evolved to fulfill the needs of plant physiological processes and are natural for the plant cells but not natural to the human cell. Epidemiological data suggest a possible protective effect of phytoestrogen if consumed during adolescence, but later on in life this effect is not clear. The utility of phytoestrogen as a "natural and safe" alternative to estrogen in alleviating vasomotor symptoms has failed the test in randomized clinical trials. Because many breast cancer sufferers seek in phytoestrogen a relief of estrogen deficiency symptoms, the possible interaction of such remedies with risk of recurrence of breast cancer or interference with tamoxifen action should not be overlooked.

Naringenin and 17beta-estradiol coadministration prevents hormone-induced human cancer cell growth

Flavonoids have been described as health-promoting, disease-preventing dietary components. In vivo and in vitro experiments also support a protective effect of flavonoids to reduce the incidence of certain hormone-responsive cancers. In particular, our previous results indicate that the flavanone naringenin (Nar), decoupling estrogen receptor alpha (ERalpha) action mechanisms, drives cancer cells to apoptosis. Because these studies were conducted in the absence of the endogenous hormone 17beta-estradiol (E2), the physiological relevance of these findings is not clear. We investigate whether the antiproliferative Nar effect persists in the presence of physiological E2 concentration (i.e. 10 nM), using both ERalpha-transfected (HeLa cells) and ERalpha-containing (HepG2 cells) cancer cell lines. Ligand saturation experiments indicate that Nar decreases the binding of E2 to ERalpha without impairing the estrogen response element (ERE)-driven reporter plasmid activity. In contrast, Nar stimulation prevents E2-induced extracellular regulated kinases (ERK1/2) and AKT activation and still induces the activation of p38, the proapoptotic member of mitogen-activating protein kinase (MAPK) family. As a consequence, Nar stimulation impedes the E2-induced transcription of cyclin D1 promoter and reverts the E2-induced cell proliferation, driving cancer cell to apoptosis. Thus, these results suggest that coexposure to this low-affinity, low-potency ligand for ERalpha specifically antagonizes the E2-induced ERalpha-dependent rapid signals by reducing the effect of the endogenous hormone in promoting cellular proliferation. As a whole, these data indicate that Nar is an excellent candidate as a chemopreventive agent in E2-dependent cancers.

Effects of dietary flaxseed lignan extract on symptoms of benign prostatic hyperplasia

A flaxseed lignan extract containing 33% secoisolariciresinol diglucoside (SDG) was evaluated for its ability to alleviate lower urinary tract symptoms (LUTS) in 87 subjects with benign prostatic hyperplasia (BPH). A randomized, double-blind, placebo-controlled clinical trial with repeated measurements was conducted over a 4-month period using treatment dosages of 0 (placebo), 300, or 600 mg/day SDG. After 4 months of treatment, 78 of the 87 subjects completed the study. For the 0, 300, and 600 mg/day SDG groups, respectively, the International Prostate Symptom Score (IPSS) decreased -3.67 +/- 1.56, -7.33 +/- 1.18, and -6.88 +/- 1.43 (mean +/- SE, P = .100, < .001, and < .001 compared to baseline), the Quality of Life score (QOL score) improved by -0.71 +/- 0.23, -1.48 +/- 0.24, and -1.75 +/- 0.25 (mean +/- SE, P = .163 and .012 compared to placebo and P = .103, < .001, and < .001 compared to baseline), and the number of subjects whose LUTS grade changed from "moderate/severe" to "mild" increased by three, six, and 10 (P = .188, .032, and .012 compared to baseline). Maximum urinary flows insignificantly increased 0.43 +/- 1.57, 1.86 +/- 1.08, and 2.7 +/- 1.93 mL/second (mean +/- SE, no statistical significance reached), and postvoiding urine volume decreased insignificantly by -29.4 +/- 20.46, -19.2 +/- 16.91, and -55.62 +/- 36.45 mL (mean +/- SE, no statistical significance reached). Plasma concentrations of secoisolariciresinol (SECO), enterodiol (ED), and enterolactone (EL) were significantly raised after the supplementation. The observed decreases in IPSS and QOL score were correlated with the concentrations of plasma total lignans, SECO, ED, and EL. In conclusion, dietary flaxseed lignan extract appreciably improves LUTS in BPH subjects, and the therapeutic efficacy appeared comparable to that of commonly used intervention agents of alpha1A-adrenoceptor blockers and 5alpha-reductase inhibitors.

Regulation of cellular signals from nutritional molecules: a specific role for phytochemicals, beyond antioxidant activity

Phytochemicals (PhC) are a ubiquitous class of plant secondary metabolites. A "recommended" human diet should warrant a high proportion of energy from fruits and vegetables, therefore providing, among other factors, a huge intake of PhC, in general considered "health promoting" by virtue of their antioxidant activity and positive modulation, either directly or indirectly, of the cellular and tissue redox balance. Diet acts through multiple pathways and the association between the consumption of specific food items and the risk of degenerative diseases is extremely complex. Recent literature suggests that molecules having a chemical structure compatible with a putative antioxidant capacity can actually "perform" activities and roles independent of such capacity, interacting with cellular functions at different levels, such as affecting enzyme activities, binding to membrane or nuclear receptors as either an elective ligand or a ligand mimic. Inductive or signaling effects may occur at concentrations much lower than that required for effective antioxidant activity. Therefore, the "antioxidant hypothesis" is to be considered in some cases an intellectual "shortcut" possibly biasing the real understanding of the molecular mechanisms underlying the beneficial effects of various classes of food items. In the past few years, many exciting new indications elucidating the mechanisms of polyphenols have been published. Here, we summarize the current knowledge of the mechanisms by which specific molecules of nutritional interest, and in particular polyphenols, play a role in cellular response and in preventing pathologies. In particular, their direct interaction with nuclear receptors and their ability to modulate the activity of key enzymes involved in cell signaling and antioxidant responses are presented and discussed.

Tissue distribution of isoflavones in ewes after consumption of red clover silage

When discovered in the 50's, isoflavones were suspected to provoke infertility syndrome in sheep grazing on clover. Many others effects of these phytoestrogens have been documented afterwards. To determine the distribution of isoflavone metabolites in ewe tissues and look for a link with their physiological impact, two ewes were fed a diet containing 50% red clover silage (variety Pawera) for one month with a daily intake of 157.6 mg/kg bw of total isoflavones. Only aglycones were fed due to the fermentation stage of the silage. At the sacrifice, isoflavone metabolites and aglycones were analyzed in blood, liver, kidney, lung, heart, muscle, ovaries, uterus, mammary glands, suprarenal glands, thymus, aorta, thyroid, pituitary gland, cerebellum, olfactory lobes, and brain hemispheres using HPLC-Coularray and LC-MS-MS. The major compounds recovered in tissues were equol and daidzein, present as glucuronides. Kidney concentrations were 10-fold higher than in other tissues. Penetration in brain was very limited. Reproductive organs contained higher concentrations of isoflavones than heart, muscle, or thymus. Distribution of isoflavones in ewe tissues is unequal and may reflect specific impact in some target tissues.

Early life and adult exposure to isoflavones and breast cancer risk

Soy and red-clover isoflavones are commonly consumed within the diet or as a dietary supplement due to a range of presumed beneficial health benefits. These isoflavones are thought to protect against heart diseases as well as breast and other types of cancer. Isoflavones are structurally similar to estrogens and may act as estrogen agonists or antagonists by binding to estrogen receptors. Because of an increased use of isoflavones in processed foods and dietary supplements as well as the greater consumption of soy products, dietary intakes of isoflavones are increasing in children and adolescents in North America. Estrogens are a known component of numerous hormone related cancers including breast cancer. It is with these facts in mind that we review the existing epidemiological and experimental animal studies for a resolution to a proposed correlation between increased isoflavone consumption and breast cancer. There is conflicting evidence from epidemiological, intervention and experimental animal studies regarding the chemopreventing effects of soy isoflavones in breast cancer. Isoflavones are weak estrogens and their effect depends upon the dose, time of exposure and species involved. It would, therefore, not be safe to indisputably accept soy or red-clover as a source of isoflavone resource to prevent breast cancer.

Soy isoflavones decrease the catechol-O-methyltransferase-mediated inactivation of 4-hydroxyestradiol in cultured MCF-7 cells

The tissue concentrations of the female sex hormone 17beta-estradiol (E2) and its reactive catechol metabolites such as 4-hydroxyestradiol (4-HO-E2) play important roles in hormonal carcinogenesis. They are influenced by the activity of local enzymes involved in the metabolic activation and inactivation of E2. In the mammary gland, catechol estrogens are predominately inactivated by catechol-O-methyltransferase (COMT). Food supplements containing the soy isoflavones genistein and daidzein are consumed because they are believed to protect from breast cancer; however, this proposed benefit is controversial. The aim of the present study was to investigate the influence of soy isoflavones on the gene expression and activity of COMT in cultured human mammary adenocarcinoma MCF-7 cells. Levels of COMT messenger RNA (mRNA) were determined by reverse transcription/competitive polymerase chain reaction and COMT activity was determined by high-performance liquid chromatography analysis of the methylation products of both the model substrate quercetin and the physiological relevant substrate 4-HO-E2. Our study demonstrates for the first time that soy isoflavones at hormonally active concentrations cause a significant reduction of both COMT mRNA levels and COMT activity as well as of the methylation of 4-HO-E2. Experiments using the estrogen receptor (ER) antagonist ICI 182,780 support a role of the ER in the isoflavone-induced down-regulation of COMT expression. Thus, this study not only demonstrates that hormonally active concentrations of soy isoflavones inhibit the detoxification of catechols in this human breast cancer cell line but also implies that diet might influence COMT activity to a greater extent than heretofore recognized.

Analysis of biologically active compounds in water by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry

A new method based on ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight mass spectrometry ((Q-ToF)-MS) was developed for the analysis of 32 biologically active compounds including anti-inflammatories, analgesics, lipid regulators, psychiatric drugs, anti-ulcer agents, antibiotics, beta-blockers and phytoestrogens. This new method allows chromatographic analysis in 14 min, with instrumental detection limits from 2 to 84 pg, and limits of quantification ranging from 0.1 to 15 ng/L in tap water, and from 2 to 300 ng/L in wastewater. The potential of liquid chromatography with triple quadrupole mass spectrometry (LC/QqQ-MS) was compared with that of UPLC/(Q-ToF)-MS for the analysis of biologically active compounds in water samples. LC/Q-ToF provides accurate mass information and a significantly higher mass resolution than quadrupole analyzers. The available mass resolution of ToF instruments diminishes the problem of isobaric interferences and helps the analysis of trace compounds in complex samples. In this work UPLC/Q-ToF chromatograms were recorded containing full scan spectral data. The m/z values of analytes were extracted from the total ion chromatogram (TIC) and the accurate masses of the compounds were obtained. In addition, to increase the selectivity of ToF measurements a narrow accurate mass interval (20 m m/z units mass window) was used to reconstruct the chromatographic traces. However, regarding quantitative performance in terms of dynamic range and limits of detection (LODs), typical LODs achieved by QqQ instruments operating in multiple-reaction monitoring (MRM) mode ranged from 1 to 50 ng/L in wastewater, and the linear response for QqQ instruments generally covers three orders of magnitude. This is an important advantage over ToF instruments and one of the reasons why QqQ instruments are widely used in quantitative environmental analysis.

Quantitative structure-activity relationships for a series of selective estrogen receptor-beta modulators

The estrogen receptor-beta subtype (ERbeta) is an attractive drug target for the development of novel therapeutic agents for hormone replacement therapy. Hologram quantitative structure-activity relationships (HQSAR) were conducted on a series of 6-phenylnaphthalene and 2-phenylquinoline derivatives, employing values of ERbeta binding affinity. A training set of 65 compounds served to derive the models. The best statistical HQSAR model (q(2) = 0.73 and r(2) = 0.91) was generated using atoms, bonds, connections and donor and acceptor as fragment distinction parameters, and fragment size default (4-7) with hologram length of 199. The model was used to predict the binding affinity of an external test set of 16 compounds, and the predicted values were in good agreement with the experimental results. The final HQSAR model and the information obtained from 2D contribution maps should be useful for the design of novel ERbeta modulators having improved affinity.

Antioxidant activity of Sicilian pistachio (Pistacia vera L. var. Bronte) nut extract and its bioactive components

Pistacia vera L. is the only species of Pistacia genus producing edible nuts. This paper investigates the antioxidant potential of a Sicilian variety of pistachio nut by chemical as well as biological assays and measured antioxidant vitamins and a number of antioxidant polyphenols in either the hydrophilic and/or the lipophilic nut extract. In accordance with the majority of foods, the total antioxidant activity, measured as a TAA test, was much higher (50-fold) in the hydrophilic than in the lipophilic extract. Substantial amounts of total phenols were measured. The hydrophilic extract inhibited dose-dependently both the metal-dependent and -independent lipid oxidation of bovine liver microsomes, and the Cu+2-induced oxidation of human low-density lipoprotein (LDL). Peroxyl radical-scavenging as well as chelating activity of nut components may be suggested to explain the observed inhibition patterns. Among tocopherols, gamma-tocopherol was the only vitamin E isomer found in the lipophilic extract that did not contain any carotenoid. Vitamin C was found only in a modest amount. The hydrophilic extract was a source of polyphenol compounds among which trans-resveratrol, proanthocyanidins, and a remarkable amount of the isoflavones daidzein and genistein, 3.68 and 3.40 mg per 100 g of edible nut, respectively, were evaluated. With the exception of isoflavones that appeared unmodified, the amounts of other bioactive molecules were remarkably reduced in the pistachio nut after roasting, and the total antioxidant activity decreased by about 60%. Collectively, our findings provide evidence that the Sicilian pistachio nut may be considered for its bioactive components and can effectively contribute to a healthy status.

Phytoestrogen content of foods consumed in Canada, including isoflavones, lignans, and coumestan

Phytoestrogens may play a role in hormone-related diseases such as cancer, but epidemiological and clinical data are conflicting in part due to inadequate databases used in intake estimation. A database of nine phytoestrogens in foods relevant to Western diets was developed to more accurately estimate intakes. Foods (N = 121) available in Ontario, Canada were prepared as commonly consumed and analyzed for isoflavones (genistein, daidzein, glycitein, formononetin), lignans (secoisolariciresinol, matairesinol, pinoresinol, lariciresinol), and coumestan (coumestrol) using gas chromatography-mass spectrometry methods. Data were presented on an as is (wet) basis per 100 g and per serving. Food groups with decreasing levels of total phytoestrogens per 100 g are nuts and oilseeds, soy products, cereals and breads, legumes, meat products, and other processed foods that may contain soy, vegetables, fruits, alcoholic, and nonalcoholic beverages. Soy products contain the highest amounts of isoflavone, followed by legumes, meat products and other processed foods, cereals and breads, nuts and oilseeds, vegetables, alcoholic beverages, fruits, and nonalcoholic beverages. Decreasing amounts of lignans are found in nuts and oilseeds, cereals and breads, legumes, fruits, vegetables, soy products, processed foods, alcoholic, and nonalcoholic beverages. The richest sources of specific phytoestrogens, including coumestrol, were identified. The database will improve phytoestrogen intake estimation in future epidemiological and clinical studies particularly in Western populations.

Prenylflavonoids as nonsteroidal phytoestrogens and related structure-activity relationships

In the search for estrogen receptor (ER) modulators, a series of prenylflavonoids were found to be widely distributed amongst tonic herbal medicines and to possess estrogen-like activity in MCF-7/BOS cells, as evaluated by an estrogen-screening assay. Cell-cycle analysis revealed that the stimulatory effects of these compounds toward cell proliferation were elicited at the G1-S checkpoint and could significantly increase the S-phase population of MCF-7 cells under hormone-free conditions. ER-responsive gene (PS2, PgR) and protein (PgR) expression was also detected; mRNA and protein-expression levels for PS2 and PgR were up-regulated by the compounds in a dose-dependent manner. These effects could be inhibited by the pure ER antagonist ICI 182,780 ((7alpha-[9-{4,4,5,5,5-pentafluoropentyl}sulfinyl]nonyl)estra-1,3,5(10)-triene-3,17beta-diol). It was therefore concluded that the estrogen-like effects of these prenylflavonoids were mediated primarily through ERs. Furthermore, to explore the structure-activity relationship based on the estrogen receptor and detailed molecular mechanisms among the prenylflavonoids, protein-ligand docking simulations were carried out by using the DS-MODELING software package. The binding affinity of each prenylflavonoid toward ERalpha was scored, and the receptor-ligand interaction was also analyzed to provide the simulation characteristics of virtual molecular recognition mechanisms.

Influence of phytoestrogens on the proliferation and expression of adhesion receptors in human mammary epithelial cells in vitro

Tumor metastasis is associated with integrin-mediated adhesion and hyaluronan receptor expression. Accumulating evidence suggests that phytoestrogens, which are naturally occurring, plant-derived phytochemicals, could inhibit tumorigenesis during the development of breast cancer. Less is known, however, about the regulation of adhesion receptors by phytoestrogens and, particularly, their potency to influence proliferation of primary human breast cells in comparison with the steroid hormone 17beta-estradiol. Throughout the proliferation experiments, we used primary human mammary epithelial cells from normal tissue that was derived from plastic surgery. For receptor expression (beta1, alpha2, alpha3, CD44), we used the cell line MCF-7. Both investigations were carried out by flow cytometry. The phenotype of primary human mammary epithelial cells was microscopically characterized by analyzing the distribution of ZO-1, cytokeratin and the estrogen receptors alpha and beta. The integrins and the hyaluronan receptor were significantly up-regulated with 17beta-estradiol in human MCF-7 cells. In contrast, genistein and daidzein did not affect the expression at a concentration of 100 micromol/l. In all proliferation experiments with a significant stimulation of the primary human mammary epithelial cell growth due to 17beta-estradiol, in general, genistein and daidzein did not influence S-phase and G2/M-phase cells. Additionally, the stimulative effect of 17beta-estradiol could be inhibited. As the phytoestrogens do not up-regulate adhesion receptors in human breast cells and, regarding proliferation, are able to abolish the stimulatory effect of 17beta-estradiol, we suggest that phytoestrogens could have beneficial effects for the prevention or inhibition of carcinogenesis in hormone-dependent malignancies.

Application of coulometric electrode array detection to the analysis of isoflavonoids and lignans

A comprehensive review of the available methods for the analysis of isoflavonoids and lignans in biological matrices based on coulometric electrode array detection (CEAD) is presented. Different aspects such as sample extraction and purification procedures as well as instrumental settings and method validation are discussed. Comparisons with other available protocols using different detection techniques such as mass spectrometry or immunoassay are also reported to underline the versatility and reliability of the detector. Practical notes and tips for scientists working with CEAD are also provided.

Metabolic phenotype of isoflavones differ among female rats, pigs, monkeys, and women

Various physiologic effects of soy food consumption have been attributed to the estrogenic actions of isoflavones. The order of estrogen receptor binding potency of soy-derived isoflavone aglycones is equol > genistein > daidzein, and their conjugates are less potent. Because the metabolic profile may be an important determinant of bioactivity after soy intake, we studied the serum and urine isoflavone concentrations in 3 animal models and compared them with isoflavone profiles in women. Female Sprague-Dawley rats, Hampshire/Duroc Cross pigs, cynomolgus monkeys, and women were fed diets containing soy protein isolate. Isoflavones and their metabolites were measured by LC-MS or electrochemical detection. Equol represented approximately 77 and 52% (molar ratio) of summed serum isoflavones (isoflavones plus metabolites) in rats and cynomolgus monkeys, respectively. Equol was undetectable in pig serum and human plasma, but daidzein and genistein contributed >88% of summed circulating isoflavones. Monkey and rat urine contained high levels of aglycones (>85% and >32%, respectively), whereas pigs and women excreted isoflavone mainly in the form of glucuronides (>80%), with <10% as aglycones. Isoflavones in human plasma were predominantly glucuronides (75%) with 24% as sulfates and <1% as aglycones; in monkey serum, however, 64% of isoflavones were sulfates, 30% glucuronides, and 6% aglycones. Equol was also a major serum metabolite of 6-mo-old rhesus monkeys (80% of summed isoflavones). Thus, there were significant interspecies differences in isoflavone metabolism, and the overall metabolic profile of pigs was closer to that of women than that of rats or monkeys.