Soy-containing Foods Research Articles

Effect of Mono- and Polysaccharide on the Structure and Property of Soy Protein Isolate during Maillard Reaction.

As a protein extracted from soybeans, soy protein isolate (SPI) may undergo the Maillard reaction (MR) with co-existing saccharides during the processing of soy-containing foods, potentially altering its structural and functional properties. This work aimed to investigate the effect of mono- and polysaccharides on the structure and functional properties of SPI during MR. The study found that compared to oat β-glucan, the reaction rate between SPI and D-galactose was faster, leading to a higher degree of glycosylation in the SPI-galactose conjugate. D-galactose and oat β-glucan showed different influences on the secondary structure of SPI and the microenvironment of its hydrophobic amino acids. These structural variations subsequently impact a variety of the properties of the SPI conjugates. The SPI-galactose conjugate exhibited superior solubility, surface hydrophobicity, and viscosity. Meanwhile, the SPI-galactose conjugate possessed better emulsifying stability, capability to produce foam, and stability of foam than the SPI-β-glucan conjugate. Interestingly, the SPI-β-glucan conjugate, despite its lower viscosity, showed stronger hypoglycemic activity, potentially due to the inherent activity of oat β-glucan. The SPI-galactose conjugate exhibited superior antioxidant properties due to its higher content of hydroxyl groups on its molecules. These results showed that the type of saccharides had significant influences on the SPI during MR.

The impact of endometriosis on dietary choices and activities of everyday life: a cross-sectional study.

Endometriosis is characterized by ectopic endometrial tissue and severe pain; frequently, women afflicted by this condition resort to non-medical interventions, such as dietary modifications. The aim of this study is to assess the impact of endometriosis on dietary patterns and quality of life. An online survey was conducted among Italian women with endometriosis to gather self-reported demographic, clinical, dietary habit, and daily life data post-diagnosis. A total of 4,078 participants were included. Following an endometriosis diagnosis, 66% reported changes in eating habits, and 92% experienced a decline in daily life. Respondents chose dietary interventions: gluten-free (15%), anti-inflammatory (8%), Mediterranean (7.1%), or ketogenic (4%) diets, to improve health and reduce symptoms. The study revealed a shift in eating habits, with increased consumption of vegetables, fruits (10%), cereals, legumes (6.6%), and fish (4.5%), while reducing dairy products (18.4%), soy-containing foods (6.7%), and high saturated fats (8%). Eating habit changes correlated with endometriosis stages and worsened daily life. Educational level, endometriosis stages, years of symptoms, and eating habit changes linked to changes in daily life. Our findings emphasize the importance of monitoring eating behaviors to prevent unhealthy habits and malnutrition in women with endometriosis. Further studies are needed to evaluate how different diets impact symptoms and enhance daily life for these individuals.

Modular Engineering of Saccharomyces cerevisiae for De Novo Biosynthesis of Genistein.

Genistein, a nutraceutical isoflavone, has various pharmaceutical and biological activities which benefit human health via soy-containing food intake. This study aimed to construct Saccharomyces cerevisiae to produce genistein from sugar via a modular engineering strategy. In the midstream module, various sources of chalcone synthases and chalcone isomerase-like proteins were tested which enhanced the naringenin production from p-coumaric acid by decreasing the formation of the byproduct. The upstream module was reshaped to enhance the metabolic flux to p-coumaric acid from glucose by overexpressing the genes in the tyrosine biosynthetic pathway and deleting the competing genes. The downstream module was rebuilt to produce genistein from naringenin by pairing various isoflavone synthases and cytochrome P450 reductases. The optimal pair was used for the de novo biosynthesis of genistein with a titer of 31.02 mg/L from sucrose at 25 °C. This is the first report on the de novo biosynthesis of genistein in engineered S. cerevisiae to date. This work shows promising potential for producing flavonoids and isoflavonoids by modular metabolic engineering.

Содержание изофлавоноидов в сое и пищевых продуктах с ее использованием

Soy is exceptionally rich in isoflavonoids, which are linked to various health benefits. The aim of the research was to determine the content of isoflavonoids in soy and some soy-containing foods. 
 The research featured the Sentyabrinka soy variety developed at the All-Russian Research Institute of Soy, as well as such novel soy-containing foods as soy-and-pumpkin drinks and desserts, e.g. soy-and-pumpkin okara crackers. The content of isoflavonoids was determined by high performance liquid chromatography using a Millichrom F-02 chromatograph. 
 The total content of isoflavonoids was 221.10 mg/100 g in the soy beans, 44.50 mg/100 g – in the soy-and-pumpkin dessert, 36.15 mg/100 g – in the soy-and-pumpkin jelly, 30.80 mg/100 g – in the cracker with soy-and-pumpkin okara, 21.19 mg/100 g – in the protein drink, 12.72 mg/100 g – in the vitamin drink. The samples were tested for such isoflavonoids as genistein, diadzein (major), and glycetein (minor), which took the form of aglycones, glycosides (genistin, diadzin, and glycitein), and malonyl derivatives of glycosides. The highest content of malonyl diadzin and malonyl genistin was registered both in the soy beans and the soy-containing foods: from 42.56 in the crackers to 67.50% in the soy beans. 
 The content of isoflavonoids in the soy-containing food products depended on the formulation and production technology, namely, on the amount of soy. A daily intake of 200 g of soy-and-pumpkin drink or 100 g of soy-containing dessert could provide the daily intake of isoflavonoids, which makes these products beneficial for human health.

Detection of Genetically Modified Protein in Soy-containing Foods

The use of genetically modified organisms (GMO) in food is a highly public and controversial issue. We have used an enzyme-linked immunosorbent assay (ELISA) to detect the genetically modified protein 5-enol-pyruvylshikimate-3-phosphate (EPSP) synthase within soy-containing food products from the grocery store. We found that EPSP synthase is detectable in 3 out of 5 food products tested. Of specific interest, we found contamination levels of EPSP synthase (0.36%) in Heinz' Pablum Soya Cereal, which is currently deemed to be free of genetic modifications by the company as well as by Greenpeace Canada. These results demonstrate that genetically modified organisms are present in foods commonly available for human consumption and that the widespread use of this technology may make it difficult to ensure that any given product is free of all traces of genetically modified protein.

Soy Isoflavones Inhibit Endothelial Cell Dysfunction and Prevent Cardiovascular Disease.

Soybeans are among the most popular foods worldwide, and intake of soy-containing foods has been associated with many health benefits in part because of it structure similar to estrogen. Epidemiologic studies have demonstrated that soy consumption improves serum profiles of hypercholesterolemic patients. Several studies have also indicated an inverse relationship between the consumption of soy isoflavones and the incidence of cardiovascular diseases (CVD). Soy is a rich dietary source of isoflavones. The main soy isoflavones are daidzein and genistein; equol, another isoflavone and a major intestinal bacterial metabolite of daidzein, is generated by enterobacterial effects. Many isoflavones have antioxidative effects and anti-inflammatory actions, as well as induce nitric oxide production to maintain a healthy endothelium and prevent endothelial cell dysfunction. These effects may limit the development of atherosclerosis and CVD and restore healthy endothelial function in altered endothelia. Although the evidence supporting the benefits of soy isoflavones in CVD prevention continues to increase, the association between soy isoflavones and disease is not fully understood. This review summarized recent progress in identifying the preventive mechanisms of action of dietary soybean isoflavones on vascular endothelial cells. Furthermore, it describes the beneficial roles that these isoflavones may have on endothelial dysfunction-related atherosclerosis.

Evaluation of new natural deep eutectic solvents for the extraction of isoflavones from soy products

Natural deep eutectic solvents (NADESs) are considered to be new, safe solvents in green chemistry that can be widely used in many chemical processes such as extraction or synthesis.In this study, a simple extraction method based on NADES was used for the isolation of isoflavones (daidzin, genistin, genistein, daidzein) from soy products. Seventeen different NADES systems each including two or three components were tested. Multivariate data analysis revealed that NADES based on a 30% solution of choline chloride: citric acid (molar ratio of 1:1) are the most effective systems for the extraction of isoflavones from soy products. After extraction, the analytes were detected and quantified using ultra-high performance liquid chromatography with ultraviolet detection (UHPLC-UV).The proposed NADES extraction procedure achieved enrichment factors up to 598 for isoflavones and the recoveries of the analytes were in the range 64.7–99.2%. The developed NADES extraction procedure and UHPLC-UV determination method was successfully applied for the analysis of isoflavones in soy-containing food samples. The obtained results indicated that new natural deep eutectic solvents could be an alternative to traditional solvents for the extraction of isoflavones and can be used as sustainable and safe extraction media for another applications.

Manmade and natural oestrogens: opposite effects on assisted reproduction

In a new study, a dramatic decrease in the frequency of implantation, pregnancy and live birth is associated with increased urine levels of bisphenol A (BPA) in women undergoing in vitro fertilization (IVF). However, in women who consume soy-containing foods, the interfering effect of BPA on IVF success is negated.

Clinical reactivity to soy is best identified by component testing to Gly m 8

Soy allergy affects approximately 0.4% of young children in the USA.1 A majority of children with soy allergy become tolerant over time,2 which makes it important that allergists reassess these patients on a regular basis. An accurate assessment of patients with a suspected soy allergy is vital, because avoidance of soy is extremely difficult, it is a common ingredient in processed foods, and consumption of soy-containing food additives (soy isolate, soy concentrate, and soy flour) is increasing in Western diets.

Effects of Dietary Genistein on Hormone-Dependent Rat Mammary Carcinogenesis Induced by Ethyl Methanesulphonate

Genistein, a major soy isoflavone having weak estrogenic activities, has been suggested to reduce the risk of breast cancer incidence. However, many studies have yielded inconsistent results. We investigated the effects of dietary genistein on the development of breast cancer using ethyl methanesulphonate (EMS) chemically induced rat model of hormone-dependent mammary carcinoma. Female Wistar King A rats were orally given EMS for 12 wk and fed isoflavone-free NIH-07PLD diets with or without genistein, beginning immediately after weaning period. All EMS-treated rats fed either diet developed estrogen and/or progesterone receptor-positive mammary carcinoma by 24 wk. The addition of either low or high genistein, which produced the plasma concentrations comparable with those observed in humans consuming high soy diets, did not show any preventive activity. Soy-containing pellet food, exhibiting substantial plasma concentrations of isoflavones such as genistein, daidzein, equol, and glycitein, significantly increased the latency periods, compared to either NIH-07PLD diet with low (P = 0.027) or high (P = 0.034) genistein. Body weights, total EMS uptakes, and urinary estradiol concentrations were not significantly different among groups. These data indicate that genistein does not exert clear preventive effects and that isoflavone components other than genistein might be preventive against hormone-dependent mammary carcinogenesis.

Effect of Dietary Genistein on Hormone‐dependent Rat Mammary Carcinoma Induced by Ethyl Methanesulphonate (EMS)

Although genistein (GEN), a major soy isoflavone, has been shown to reduce the risk of breast cancer (BC) incidence, many experimental studies have yielded the inconsistent results. We investigated the effects of GEN on the development of BC using the EMS chemically induced rat model of hormone‐dependent BC. Female WKA rats were orally given EMS for 12 weeks and fed the soy‐isoflavone‐free NIH‐07PLD diets with or without GEN. All EMS‐treated rats fed either diet developed ER‐ and/or PgR‐positive hormone‐dependent mammary carcinoma by 24 weeks. Compared with GEN‐free diet, the addition of either low or high GEN to GEN‐free diet, which produced plasma concentrations of GEN comparable with those observed in humans consuming high or more soy diets did not show any preventive activity on the development of EMS‐induced hormone‐dependent BC. Soy‐containing food CE2, which resulted in the modest plasma concentration of isoflavones such as GEN, daidzein, equol, and glycitein, increased the latency periods, compared to either isoflavone‐free diets with (p=0.008) or without GEN (p=0.052). The body weight, total EMS uptakes, and urine estradiol concentrations were not significantly different between these 4 groups. These data indicate that GEN does not exert clear preventive effects on estrogen‐dependent mammary carcinogenesis and that isoflavones other than GEN may be responsible for the prevention of BC.

Review: Detecting Genetically Modified Food by PCR

Book Review| February 01 2012 Review: Detecting Genetically Modified Food by PCR Detecting Genetically Modified Food by PCR (Carolina Biological) Laurie A. Host Laurie A. Host Assistant Professor of Biology, Harford Community College, Bel Air, MD 21015, lhost@harford.edu Search for other works by this author on: This Site PubMed Google Scholar The American Biology Teacher (2012) 74 (2): 128. https://doi.org/10.1525/abt.2012.74.2.14 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Laurie A. Host; Review: Detecting Genetically Modified Food by PCR. The American Biology Teacher 1 February 2012; 74 (2): 128. doi: https://doi.org/10.1525/abt.2012.74.2.14 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentThe American Biology Teacher Search Genetic engineering has allowed scientists to express specific genes in foods, creating desired effects such as pesticide and herbicide resistance, increased nutritional value, and stress tolerance. The benefits and risks of consuming genetically modified organisms (GMOs) are hotly debated worldwide. "Detecting Genetically Modified Food by PCR" is a hands-on laboratory investigation designed to bring this topic into the classroom. Students use the kit to test corn- or soy-containing food products of their choice for the presence of genetic modification. Wild-type and Round-Up Ready soybeans are provided in the kit and used as controls. The methodology used includes DNA extraction, PCR, gel electrophoresis, and bioinformatics analysis. Given the technical nature of the investigation, the kit is most appropriate for use in high school or college courses. The material in the kit was designed by the DNA Learning Center, an organization that provides educational programs and resources for biology (http://www.dnalc.org).... You do not currently have access to this content.

Soy Food Consumption and Breast Cancer Prognosis

Contrary to earlier clinical studies suggesting that soy may promote breast tumor growth, two recent studies show that soy-containing foods are not adversely related to breast cancer prognosis. We examined, using data from the Women's Healthy Eating and Living (WHEL) study, the effect of soy intake on breast cancer prognosis. Three thousand eighty-eight breast cancer survivors, diagnosed between 1991 and 2000 with early-stage breast cancer and participating in WHEL, were followed for a median of 7.3 years. Isoflavone intakes were measured postdiagnosis by using a food frequency questionnaire. Women self-reported new outcome events semiannually, which were then verified by medical records and/or death certificates. HRs and 95% CIs representing the association between either a second breast cancer event or death and soy intake were computed, adjusting for study group and other covariates, using the delayed entry Cox proportional hazards model. As isoflavone intake increased, risk of death decreased (P for trend = 0.02). Women at the highest levels of isoflavone intake (>16.3 mg isoflavones) had a nonsignificant 54% reduction in risk of death. Our study is the third epidemiologic study to report no adverse effects of soy foods on breast cancer prognosis. These studies, taken together, which vary in ethnic composition (two from the United States and one from China) and by level and type of soy consumption, provide the necessary epidemiologic evidence that clinicians no longer need to advise against soy consumption for women with a diagnosis of breast cancer.

Highlights of This Issue

Breast cancer incidence rates among U.S. non-Hispanic white women decreased by ∼7% between 2002 and 2003, related to a drop in postmenopausal hormone therapy use. Although several studies have reported that breast cancer incidence rates have continued to decline, none of these studies exclusively examined the trend after 2003. To address this, DeSantis and colleagues examined SEER registries from 2000 to 2007 and National Health Interview Survey data from 2003, 2005, and 2008. They report that the sharp decline in breast cancer incidence rates among non-Hispanic white woman that occurred between 2002 and 2003 did not continue through 2007, although hormone therapy use continued to decrease. Future studies will be necessary to better understand these breast cancer trends.The low incidence of sarcomas makes it difficult to discern heritable risks for any individual sarcoma subtype. To overcome this, Jones and colleagues grouped cases from the Utah Cancer Registry and the Utah Population Database as either complex genotype/karyotype sarcomas or balanced translocation sarcomas to calculate risks for relatives of sarcoma patients. Although there was no evidence for excess relatedness for the balanced translocation sarcomas, there was strong familiarity among complex genotype sarcomas. This study indicates that genetics may play a key role in complex genotype sarcomagenesis.Gastric cancer incidence in African Americans is twice that of whites, and differing prevalence of Helicobacter pylori (H. pylori) isolates may explain the disparity. To explore this, Epplein and colleagues assessed serum levels of antibodies against different H. pylori proteins as well as African and European admixtures in African American and white study participants. African American race was associated with 2- to 6-fold increased odds for the presence H. pylori proteins. Compared with whites, African Americans with “high” African ancestry had 5.2-fold increased odds of H. pylori sero-positivity. Among African Americans, “high” African ancestry had 3.4-fold increased odds of H. pylori sero-positivity. These results provide a framework for better detection and prevention of gastric cancer in African Americans.Although earlier clinical studies suggested that soy may promote breast tumor growth, recent studies demonstrate that soy-containing foods are not adversely related to breast cancer prognosis. To examine this, Caan and colleagues used data from the Women's Healthy Eating and Living (WHEL) study to examine the effect of soy intake on breast cancer prognosis. They found that as soy intake increased, risk of death decreased. This study provides further evidence that clinicians no longer need to advise against soy consumption for women diagnosed with breast cancer.

The Lipid-Lowering Effects of 4 Weeks of Daily Soymilk or Dairy Milk Ingestion in a Postmenopausal Female Population

Alterations in plasma cholesterol concentrations, especially increases in low-density lipoprotein (LDL), are well-known risk factors in the development of atherosclerosis. Numerous studies have examined the lipid-lowering effects of functional soy-containing foods, but few have specifically examined soymilk, with equivocal findings reported. In September 2008, a single-blind, randomized, controlled trial was conducted on 32 postmenopausal women at Baylor University, Waco, TX, USA. After a 2-week run-in period, subjects were randomly assigned to consume three servings of vanilla soy (n = 16) or reduced-fat dairy (n = 16) milk per day for 4 weeks. Plasma lipid profiles were obtained pre- and post-supplementation. Plasma high-density lipoprotein, LDL, and triglycerides were not significantly different between groups post-intervention (P = .45) or from baseline (P = .83). Separate analysis of plasma total cholesterol levels yielded similar results (P = .19 and P = .92, respectively). Furthermore, subanalyses controlling for dyslipidemia (n = 23) and lipid-lowering medication usage (n = 28) did not significantly alter results. Despite good dietary compliance, our study failed to show a significant hypocholesterolemic effect of soymilk consumption in this postmenopausal female population. Potential reasons for this nonsignificant finding are discussed, and future research directions are presented.

Anaphylactic Reaction To Soy Drink In Two Patients With Birch Pollen Allergy

RATIONALE: Cross-reactivity of soy protein with birch pollen allergens was identified as the cause for their severe reactions. Kleine-Tebbe (2002) investigated IgE-mediated reactions to a soy-containing food product in patients allergic to birch pollen. The trial concluded that immediate-type symptoms in patients with birch pollen allergy after ingestion of soy protein-containing food items can result from cross-reactivity of Bet v 1-specific IgE to proteins, particularly the PR-10 soy protein SAM22.METHODS: The first patient was a 54-year old female with a previous history of O.A.S and allergy for birch pollen. Within 5 minutes after she drink soy milk, she get facial edema (periorbital and conjuncitival) and a feeling of throat closure. The second patient was a 62-year old female with allergy for grass-, and birch -pollen. After drinking soy milk, she immediately developed itching, rhinitis, thoracic thigtness, throat closure, dypsnoe, dysphagia, periorbital edema and urticaria. Prompt recovery followed epineprine, steroids and antihistamine administration.RESULTS: The results for specific IgE were negative for soy milk, and high for hazel-, alder-, birch-pollen and positive for Gly m 4. for both of them. We concluded that both patients had soy allergy based on cross-reactivity of Bet v 1-specific IgE.CONCLUSIONS: We confirmed the strong evidence that a birch pollen-related protein from soy, might cause adverse reactions in patients with high IgE titers to Bet v 1. Because of the rising popularity of soy products and the large number of birch pollen allergic patients, allergologists will be increasingly confronted with these reactions in future Patients with birch pollen allergy should be careful with the intake of soy protein. RATIONALE: Cross-reactivity of soy protein with birch pollen allergens was identified as the cause for their severe reactions. Kleine-Tebbe (2002) investigated IgE-mediated reactions to a soy-containing food product in patients allergic to birch pollen. The trial concluded that immediate-type symptoms in patients with birch pollen allergy after ingestion of soy protein-containing food items can result from cross-reactivity of Bet v 1-specific IgE to proteins, particularly the PR-10 soy protein SAM22. METHODS: The first patient was a 54-year old female with a previous history of O.A.S and allergy for birch pollen. Within 5 minutes after she drink soy milk, she get facial edema (periorbital and conjuncitival) and a feeling of throat closure. The second patient was a 62-year old female with allergy for grass-, and birch -pollen. After drinking soy milk, she immediately developed itching, rhinitis, thoracic thigtness, throat closure, dypsnoe, dysphagia, periorbital edema and urticaria. Prompt recovery followed epineprine, steroids and antihistamine administration. RESULTS: The results for specific IgE were negative for soy milk, and high for hazel-, alder-, birch-pollen and positive for Gly m 4. for both of them. We concluded that both patients had soy allergy based on cross-reactivity of Bet v 1-specific IgE. CONCLUSIONS: We confirmed the strong evidence that a birch pollen-related protein from soy, might cause adverse reactions in patients with high IgE titers to Bet v 1. Because of the rising popularity of soy products and the large number of birch pollen allergic patients, allergologists will be increasingly confronted with these reactions in future Patients with birch pollen allergy should be careful with the intake of soy protein.

Bone development in female rats maintained with soy-free or soy-containing food as determined by computer-assisted tomography and serum bone markers

The development of bone in immature rats and in aged rats has not been thoroughly studied. Therefore, we investigated the development of bones in young, middle-aged, and aged female rats. Because most rat chows contain soy proteins, including estrogenic isoflavones, as a source of protein, comparison of effects on mineral density and on areas of the cancellous and cortical parts of the metaphysis of the tibia as measured by quantitative computer tomography in animals fed with soy-free and soy-containing food was made. As surrogate parameters of bone metabolism serum, osteocalcin (OC) and the breakdown products of bone collagen--the Crosslaps--were also determined. The cancellous density increased between day 25 after birth to reach peak bone mass at 90 days of age; in 18-and 20-month-old animals, significant reduction was observed that was more profound in the animals fed with soy-free food. Serum OC and the Crosslaps were highest in 15-day-old and lowest in 9-, 18-, and 20-month-old animals. Animals fed with soy-containing food had significantly higher osteocalcin levels at day 15 and at 9 and 18 months of age. In the aged animals, intake of soy isoflavones that have an estrogenic effect appears to exert beneficial effects as these aged animals lost less cancellous bone, as indicated by their surrogate parameters of metabolism in the serum. It is concluded that exorbitantly high bone turnover is present in immature and peripubertal rats. Raising and keeping female rats under soy-free or soy-containing conditions has marked effects on several bone parameters that are of particular relevance in aged animals.

Determination of Alachlor in food products by a fluorescence polarization immunoassay

A procedure for the determination of Alachlor in liquid media using a fluorescence polarization immunoassay (FPIA) was developed. The effects of the structure and purification degree of a tracer (analyte with a fluorescent label) on the analytical signals, sensitivity, and selectivity in the determination of Alachlor were studied. The tracer-antibody binding constants (KT) and antigen-antibody binding constants (affinity constants KAf) were calculated, and optimum immunoreagent pairs for the determination of Alachlor were chosen. The calibration graph was linear over the Alachlor concentration range 0.01–1.0 µg/mL; the detection limit was 8 ng/mL. The procedure was tested in the analysis of model solutions and soy-containing food products (sausages).

Protective effects of soy-isoflavones in cardiovascular disease

Epidemiological studies indicate that the consumption of soy-containing food may prevent or slow-down the development of cardiovascular disease. In endothelial cells application of a soy extract or a combination of the most abundant soy isoflavones genistein and daidzein both inhibited apoptosis, a driving force in atherosclerosis development, when applied in combination with oxidized LDL or homocysteine. Proteome analysis revealed that the stressor-induced alteration of protein expression profile was reversed by the soy extract or the genistein/daidzein mixture. Only few protein entities that could be functionally linked to mitochondrial dysfunction were regulated in common by both application forms of isoflavones. A dietary intervention with isoflavone-enriched soy extract in postmenopausal women, who generally show strongly increased cardiovascular risk due to diminished estrogen production, led to significant alterations in the steady state levels of proteins from mononuclear blood cells. The proteins identified by proteome analysis revealed that soy isoflavones may increase the anti-inflammatory response in blood mononuclear cells thereby contributing to the atherosclerosis-preventive activities of a soy-rich diet. By proteome analysis protein targets were identified in vitro in endothelial cells that respond to soy isoflavones and that may decipher molecular mechanisms through which soy products exert their protective effects in the vasculature.

Exposure of Juvenile Rats to the Phytoestrogen Daidzein Impairs Erectile Function in a Dose‐Related Manner in Adulthood

Health benefits of isoflavones such as genistein and daidzein have led to an increasing interest in consuming soybeans or soy-containing food. However, possible adverse effects of such plant estrogens on the male reproductive system, particularly penile erection, have not been sufficiently evaluated. In previous research, we observed that exposure of adult rats to daidzein could attenuate apomorphine-induced erections. To identify the impact of daidzein exposure in early life on erectile function, we evaluated erectile capacity using an apomorphine-induced erectile test and determining intracavernous pressure after exposure of juvenile rats to daidzein at a dose of 2, 20, or 100 mg/kg for 90 days. Meanwhile, the levels of sex hormones, including testosterone, luteinizing hormone, and follicle-stimulating hormone, were determined. Both subtypes of the estrogen receptor (alpha and beta) in the corpora cavernosa were also detected immunohistochemically. When the rats were examined at adulthood, we observed that those animals treated with a medium (20 mg/kg) or high (100 mg/kg) dose of daidzein, but not with a low dose (2 mg/kg), showed lower plasma testosterone levels and attenuated erectile parameters, including apomorphine-induced erections and intracavernous pressure concomitant with markedly decreased expression of estrogen receptor beta in the corpora cavernosa. However, the penis still grew to its normal size, as in controls. Thus, these results suggested that exposure of juvenile rats to daidzein in a relatively large amount could adversely affect penile erection in adulthood.