The phytoestrogen genistein induces thymic and immune changes: a human health concern?

Endocrine disrupters affect the immune system of fish: The example of the European seabass

An organism's fitness critically relies on its immune system to provide protection against parasites and pathogens. The immune system has reached its highest complexity in vertebrates, combining the highly specific adaptive with the non-specific innate immunity. In vertebrates, a complex system of steroid hormones regulates major physiological functions comprising energy metabolism, growth, reproduction and immune system performance. This allows the organism to allocate available energy according to life-history traits and environmental conditions, thus maintaining homeostasis and survival of the individual and of the population. Immune system activation must take into account the developmental stage and the nutritional state of the organism. It should respond adequately to different pathogens, but should not overperform or consume all resources for other physiological functions. This important trade-off between immunity and reproduction is balanced by oestrogen. Many of the thousands of chemicals released by humans into the environment, so-called xenobiotics, have the ability to disrupt normal endocrine function. Such endocrine-disrupting chemicals have been demonstrated to impair reproductive functions and to be responsible for numerous diseases in humans and wild life. Given that oestrogens are established modulators of immune cell populations, exogenous oestrogens and oestrogen mimics can modulate immune functions in aquatic animals, such as fish, potentially affecting wildlife and aquaculture. This review highlights the interaction of xenoestrogens with fish immunity. It particularly focusses on the thymus, a major primary immune organ, in the European seabass, Dicentrarchus labrax an important species, both for fisheries and aquaculture.

Autoantibodies Targeting the Hypothalamic-Pituitary-Ovarian Axis in Polycystic Ovary Syndrome: Emerging Key Players in Pathogenesis?

Polycystic ovary syndrome (PCOS) is a common female endocrinopathy associated with reproductive and metabolic abnormalities. PCOS is characterized by complex pathogenesis and pathophysiology. Its multifactorial etiology and heterogeneous presentation make effective treatment difficult. Endocrine abnormalities in PCOS create a vicious cycle of overriding dysfunction involving the hypothalamic-pituitary-ovarian (HPO) axis. Most research has primarily focused on identifying genetic, epigenetic, or immunological factors underlying PCOS. In recent years, new reports have emerged on the possible involvement of antibodies directed against HPO axis components in the development of PCOS. Some of these have been shown to be able to interfere with hormone receptors or receptor binding by targeting the key domains for their function. However, the evidence is heterogeneous and challenging to interpret, given the overall predisposition to high levels of various autoantibodies found in women with PCOS. This review focuses on autoantibodies affecting the HPO axis in PCOS and their potential role in the pathogenesis of PCOS. The authors discuss PCOS as a potential antibody-mediated autoimmune disease in light of recent reports on its possible pathogenesis.

Elucidating the immunomodulatory effects of phytoestrogens and their groundbreaking applications in transplantation medicine

Phytoestrogens are natural compounds found in plants and plant-based foods. When ingested, they can affect the human body in the same way as estrogen produced by the body. Phytoestrogens affect the regulation, differentiation, and production of immune cells. People who consume polyphenol and flavonoid-rich foods have lower incidences of inflammation, autoimmune diseases, and cancer. In organ transplantation, immune rejection is a lifelong problem for patients. In clinical practice, acute rejection is treated with hormonal shock or immunosuppressive drugs. However, effective reversal measures for chronic rejection, specifically for prevention, are still lacking. Recipients are also prone to post-transplant complications such as new tumors, diabetes, hyperlipidemia, hyperuricemia, and cardiovascular and cerebrovascular diseases, owing to the long-term use of immunosuppressive drugs. Phytoestrogens play a promising role in immune regulation and exert curative effects on cardiovascular diseases and cancer. In this study, we reviewed the use of phytoestrogens in the fields of immune regulation and organ transplantation.

Identification of potential therapeutic targets for systemic lupus erythematosus based on GEO database analysis and Mendelian randomization analysis

Background

Systemic lupus erythematosus (SLE) is a complex autoimmune disease. Current treatments mainly rely on immunosuppressants, which lack specificity and pose challenges during treatment. This study aims to deeply explore the molecular pathogenic mechanism of SLE through gene expression databases (GEO) and bioinformatics analysis methods, combined with Mendelian randomization analysis, to provide key clues for new therapeutic targets.

Methods

In this study, the SLE-related gene chip dataset GSE65391 was selected from the GEO database, and the data were preprocessed and statistically analyzed using R language and bioinformatics tools. Differential expression analysis, weighted gene co-expression network analysis (WGCNA), GO, and KEGG enrichment analysis were used to screen differentially expressed genes (DEGs) for functional annotation and pathway localization. Furthermore, Mendelian randomization analysis was conducted to identify core genes closely related to SLE risk, and immune cell infiltration analysis and compound molecular docking studies were performed on the core gene ISG15.

Results

The study successfully screened 3,456 DEGs and identified core gene modules highly related to SLE through WGCNA analysis, including key genes closely related to the pathogenesis of SLE, such as STAT1, DDX58, ISG15, IRF7, and IFIH1. In particular, this study found a significant positive correlation between the ISG15 gene and SLE, suggesting that it may be a potential risk factor for SLE. Additionally, through molecular docking technology, it was discovered that the ISG15 gene can effectively bind to two compounds, genistein, and flavopiridol, which have anti-inflammatory and immunosuppressive effects, respectively. This provides new potential drug targets for SLE treatment.

Discussion

As an immunomodulatory cytokine, ISG15 plays a crucial role in the pathogenesis of SLE. This study found that variations in the ISG15 gene may increase the risk of SLE and exacerbate inflammatory responses and tissue damage through multiple mechanisms. Furthermore, molecular docking revealed that genistein and flavopiridol can effectively bind to ISG15, offering a new approach for SLE treatment. These two compounds, with their anti-inflammatory and immunosuppressive properties, have the potential to slow the progression of SLE by influencing the expression and function of ISG15.

Conclusion

Through comprehensive bioinformatics analysis and Mendelian randomization analysis, this study deeply explored the molecular pathogenic mechanism of SLE and successfully identified ISG15 as a potential therapeutic target for SLE. Simultaneously, molecular docking technology revealed that two compounds, genistein and flavopiridol, have potential therapeutic effects with ISG15, providing new potential drugs for SLE treatment. These discoveries not only enhance our understanding of the pathogenesis of SLE but also provide important clues for developing new treatment strategies.

Epigallocatechin-3-gallate ameliorates lipopolysaccharide-induced acute thymus involution in mice via AMPK/Sirt1 pathway

The thymus, a site to culture the naïve T lymphocytes, is susceptible to atrophy or involution due to aging, inflammation, and oxidation. Epigallocatechin-3-gallate (EGCG) has been proven to possess anti-inflammatory, antioxidant, and antitumor activity. Here, we investigate the effects of EGCG on thymic involution induced by lipopolysaccharide (LPS), an endotoxin derived from Gram-negative bacteria. The methodology included an in vivo experiment on female Kunming mice exposed to LPS and EGCG. Morphological assessment of thymic involution, immunohistochemical detection, and thymocyte subsets analysis by flow cytometry were further carried out to evaluate the potential role of EGCG on the thymus. As a result, we found that EGCG alleviated LPS-induced thymic atrophy, increased mitochondrial membrane potential and superoxide dismutase levels, and decreased malondialdehyde and reactive oxygen species levels. In addition, EGCG pre-supplement restored the ratio of thymocyte subsets, the expression of autoimmune regulator, sex-determining region Y-box 2, and Nanog homebox, and reduced the number of senescent cells and collagen fiber deposition. Western blotting results indicated that EGCG treatment elevated LPS-induced decrease in pAMPK, Sirt1 protein expression. Collectively, EGCG relieved thymus architecture and function damaged by LPS via regulation of AMPK/Sirt1 signaling pathway. Our findings may provide a new strategy on protection of thymus from involution caused by LPS by using EGCG. And EGCG might be considered as a potential agent for the prevention and treatment of thymic involution.

A Review of the Effects of Some Extrinsic Factors on Mice Used in Research

Animals have been used in research for over 2,000 y. From very crude experiments conducted by ancient scholars, animal research, as a science, was refined over hundreds of years to what we know it as today. However, the housing conditions of animals used for research did not improve significantly until less than 100 years ago when guidelines for housing research animals were first published. In addition, it was not until relatively recently that some extrinsic factors were recognized as a research variable, even when animals were housed under recommended guidelines. For example, temperature, humidity, light, noise, vibration, diet, water, caging, bedding, etc., can all potentially affect research using mice, contributing the inability of others to reproduce published findings. Consequently, these external factors should be carefully considered in the design, planning, and execution of animal experiments. In addition, as recommended by others, the housing and husbandry conditions of the animals should be described in detail in publications resulting from animal research to improve study reproducibility. Here, we briefly review some common, and less common, external factors that affect research in one of the most popular animal models, the mouse.

Oestrogens and progesterone in human milk and their effects on infant health outcomes: A narrative review

Human milk (HM) is a complex biological system that contains a wide range of bioactive components including oestrogens and progesterone. Whilst maternal oestrogens and progesterone concentrations drop rapidly after birth, they remain detectable in HM across lactation. Phytoestrogens and mycoestrogens, which are produced by plants and fungi, are also present in HM and can interact with oestrogen receptors to interfere with normal hormone functions. Despite the potential impact of HM oestrogens and progesterone on the infant, limited research has addressed their impact on the growth and health of breastfed infants. Furthermore, it is important to comprehensively understand the factors that contribute to these hormone levels in HM, in order to establish effective intervention strategies. In this review, we have summarized the concentrations of naturally occurring oestrogens and progesterone in HM from both endogenous and exogenous sources and discussed both maternal factors impacting HM levels and relationships with infant growth.

Studies on the interaction of five triazole fungicides with human renal transporters in cells

The widespread use of triazole fungicides in agricultural production poses a potential risk to human health. This study investigates the interaction of five triazole fungicides, i.e., tebuconazole, triticonazole, hexaconazole, penconazole, and uniconazole with human renal transporters, including OAT1, OAT3, OCT2, OCTN1, OCTN2, MATE1, MATE2-K, MRP2, MDR1, and BCRP, using transgenic cell models. For uptake transporters, triticonazole was the substrate of OAT1 and OAT3 and the inhibitor of OCT2. Tebuconazole and penconazole inhibited OCTN2 (100 μM), while tebuconazole, triticonazole, hexaconazole, penconazole, and uniconazole inhibited MATE1 (100 μM). Tebuconazole and hexaconazole inhibited MATE2-K (100 μM). All five triazole fungicides were not substrates or strong inhibitors of MRP2, MDR1, and BCRP efflux transporters. Penconazole inhibited OCT2 with IC₅₀ = 1.12 μM. Penconazole and uniconazole inhibited MATE1 with IC₅₀ = 0.94 μM and 0.87 μM. Tebuconazole and hexaconazole inhibited MATE2-K with IC₅₀ = 0.96 μM and 1.04 μM, indicating that triazole fungicides may inhibit renal drug transporter activity at low concentrations. Triticonazole was transported by OAT1 and OAT3, and the K_m values of triticonazole were 5.81 ± 1.75 and 47.35 ± 14.27, respectively. Tebuconazole and uniconazole were transported by OAT3, and the K_m values of tebuconazole and uniconazole were 30.28 ± 7.18 and 87.61 ± 31.70, respectively, which may induce nephrotoxicity.

Cancer Chemotherapy via Natural Bioactive Compounds

BACKGROUND

Cancer-induced mortality is increasingly prevalent globally which skyrocketed the necessity to discover new/novel safe and effective anticancer drugs. Cancer is characterized by the continuous multiplication of cells in the human which is unable to control. Scientific research is drawing its attention towards naturally-derived bioactive compounds as they have fewer side effects compared to the current synthetic drugs used for chemotherapy.

OBJECTIVE

Drugs isolated from natural sources and their role in the manipulation of epigenetic markers in cancer are discussed briefly in this review article.

METHODS

With advancing medicinal plant biotechnology and microbiology in the past century, several anticancer phytomedicines were developed. Modern pharmacopeia contains at least 25% herbal-based remedy including clinically used anticancer drugs. These drugs mainly include the podophyllotoxin derivatives vinca alkaloids, curcumin, mistletoe plant extracts, taxanes, camptothecin, combretastatin, and others including colchicine, artesunate, homoharringtonine, ellipticine, roscovitine, maytanasin, tapsigargin,andbruceantin.

RESULTS

Compounds (psammaplin, didemnin, dolastin, ecteinascidin,and halichondrin) isolated from marine sources and animals such as microalgae, cyanobacteria, heterotrophic bacteria, invertebrates. They have been evaluated for their anticancer activity on cells and experimental animal models and used chemotherapy.Drug induced manipulation of epigenetic markers plays an important role in the treatment of cancer.

CONCLUSION

The development of a new drug from isolated bioactive compounds of plant sources has been a feasible way to lower the toxicity and increase their effectiveness against cancer. Potential anticancer therapeutic leads obtained from various ethnomedicinal plants, foods, marine, and microorganisms are showing effective yet realistically safe pharmacological activity. This review will highlight important plant-based bioactive compounds like curcumin, stilbenes, terpenes, other polyphenolic phyto-compounds, and structurally related families that are used to prevent/ ameliorate cancer. However, a contribution from all possible fields of science is still a prerequisite for discovering safe and effective anticancer drugs.

Estrogens as immunotoxicants: 17α-ethinylestradiol exposure retards thymus development in zebrafish (Danio rerio)

Estrogenic endocrine disrupting compounds (EEDCs) can cause alterations in sexual development and reproductive function of fish. Growing evidence suggests that EEDCs can also interfere with development and function of innate immunity of fish. The present study examined a potential disruptive effect of EEDCs at field-relevant concentrations on the development of adaptive immunity, more specifically the thymus. Zebrafish (Danio rerio) were exposed from fertilization until 64 days post-fertilization (dpf) to environmentally relevant (3 and 10 ng/L) concentrations of the synthetic estrogen 17α-ethinylestradiol (EE2). The exposure duration covered the period of initial thymus differentiation to maximum growth. Thymus development was assessed by histological and morphometric (thymus area) analysis, thymocyte number, and transcript levels of thymocyte marker genes. Additionally, transcript levels of the estrogen receptors (esr1 and esr2a) were determined. The EE2 exposure altered sexual development (gonad differentiation, transcript levels of hepatic vitellogenin and estrogen receptors) of zebrafish, as expected. At the same time, the EE2 treatment reduced the thymus growth (thymus area, thymocyte number) and transcript levels of thymus marker genes. The expression of the thymic estrogen receptors responded to the EE2 exposure but in a different pattern than the hepatic estrogen receptors. After the 64-day-exposure period, the juvenile fish were transferred into clean water for another 95 days to assess the reversibility of EE2-induced effects. The thymic alterations were found to be reversible in female zebrafish but persisted in males. The present study provides the first evidence that the development of the fish adaptive immune system is sensitive to EEDCs, and that this takes place at concentrations similar to those that disrupt sexual development.

Sex Differences in Glomerular Protein Expression and Effects of Soy-Based Diet on Podocyte Signaling

Background:

Kidney disease is a major public health issue arising from loss of glomerular podocyte function, and there are considerable sex differences in its prognosis. Evidence suggests a renoprotective effect of estrogen and soy diet-derived phytoestrogens, although the molecular basis for this is poorly understood.

Objective:

Here, we aim to assess sex differences in expression of key proteins associated with podocyte survival and determine the effects of dietary soy on glomerular and podocyte signaling.

Methods:

Male and female FVB mice were fed control, low (1%), and high (20%) doses of isolated soy protein (ISP) in utero and until 100 days of age. Spot urine was collected to measure proteinuria and isolated glomeruli were used to quantify activated and total levels of nephrin, Akt, and ERK1/2. To investigate protective effects of specific soy phytoestrogens, cultured podocytes were treated with or without daidzein and subject to control or high glucose as a model of podocyte injury.

Results:

Nephrin and Akt were elevated at baseline in glomeruli from females compared to males. Both sexes that were fed 1% and 20% ISP displayed robust increases in total glomerular Akt compared to controls, and these effects were more prominent in females. A similar trend at both doses in both sexes was observed with activated Akt and total nephrin. Notably, males exclusively showed increased phosphorylation of nephrin and extracellular signal-regulated kinase (ERK) at the 1% ISP dose; however, no overt changes in urinary albumin excretion or podocin levels were observed, suggesting that the soy diets did not impair podocyte function. Finally, in cultured male and female podocytes, daidzein treatment suppressed high glucose-induced ERK activation.

Conclusions:

Together, our findings reveal a putative mechanism to explain the protective influence of sex on kidney disease progression, and they provide further evidence to support a beneficial role for dietary soy in preserving glomerular function.

Natural and Synthetic Estrogens in Chronic Inflammation and Breast Cancer

The oncogenic role of estrogen receptor (ER) signaling in breast cancer has long been established. Interaction of estrogen with estrogen receptor (ER) in the nucleus activates genomic pathways of estrogen signaling. In contrast, estrogen interaction with the cell membrane-bound G-protein-coupled estrogen receptor (GPER) activates the rapid receptor-mediated signaling transduction cascades. Aberrant estrogen signaling enhances mammary epithelial cell proliferation, survival, and angiogenesis, hence is an important step towards breast cancer initiation and progression. Meanwhile, a growing number of studies also provide evidence for estrogen's pro- or anti-inflammatory roles. As other articles in this issue cover classic ER and GPER signaling mediated by estrogen, this review will discuss the crucial mechanisms by which estrogen signaling influences chronic inflammation and how that is involved in breast cancer. Xenoestrogens acquired from plant diet or exposure to industrial products constantly interact with and alter innate estrogen signaling at various levels. As such, they can modulate chronic inflammation and breast cancer development. Natural xenoestrogens generally have anti-inflammatory properties, which is consistent with their chemoprotective role in breast cancer. In contrast, synthetic xenoestrogens are proinflammatory and carcinogenic compounds that can increase the risk of breast cancer. This article also highlights important xenoestrogens with a particular focus on their role in inflammation and breast cancer. Improved understanding of the complex relationship between estrogens, inflammation, and breast cancer will guide clinical research on agents that could advance breast cancer prevention and therapy.

Soy isoflavone metabolite equol inhibits cancer cell proliferation in a PAP associated domain containing 5-dependent and an estrogen receptor-independent manner

Isoflavone is a species of polyphenol found mainly in soy and soy products. Many studies have demonstrated its estrogen receptor (ER)-dependent action. Equol is an intestinal metabolite of a major soy isoflavone daidzein. We aimed to elucidate the mechanism for ER-independent actions of equol. Equol has been shown to inhibit proliferation of HeLa human cervical cancer cells and mouse melanoma B16 cells in an ER-independent manner. Using functional genetic screening, PAP associated domain containing 5 (PAPD5), which is a non-canonical poly(A) polymerase, was identified as an essential molecule in the ER-independent action. While peroral administration of equol inhibited tumor growth of control B16 cells subcutaneously inoculated in mice, it had little effect on the growth of PAPD5-ablated B16 cells. Intriguingly, equol progressed tumor growth of the PAPD5-ablated human breast cancer MCF-7 cells, which have high ERα expression. Equol has been found to induce polyadenylation of snoRNAs in a PAPD5-depdendent manner. Furthermore, peroral equol administration increased microRNA miR-320a expression in tumors. Together, these results suggest that equol may have a dual effect on ER-positive cancer cells, acting with, antiproliferative activity through PAPD5 and exhibiting proliferative activity via ERα and the former could be associated with miR-320a.

Isoflavones derived from plant raw materials: bioavailability, anti-cancer, anti-aging potentials, and microbiome modulation

Isoflavones are secondary metabolites that represent the most abundant category of plant polyphenols. Dietary soy, kudzu, and red clover contain primarily genistein, daidzein, glycitein, puerarin, formononetin, and biochanin A. The structural similarity of these compounds to β-estradiol has demonstrated protection against age-related and hormone-dependent diseases in both genders. Demonstrative shreds of evidence confirmed the fundamental health benefits of the consumption of these isoflavones. These relevant activities are complex and largely driven by the source, active ingredients, dose, and administration period of the bioactive compounds. However, the preclinical and clinical studies of these compounds are greatly variable, controversial, and still with no consensus due to the non-standardized research protocols. In addition, absorption, distribution, metabolism, and excretion studies, and the safety profile of isoflavones have been far limited. This highlights a major gap in understanding the potentially critical role of these isoflavones as prospective replacement therapy. Our general review exclusively focuses attention on the crucial role of isoflavones derived from these plant materials and critically highlights their bioavailability, possible anticancer, antiaging potentials, and microbiome modulation. Despite their fundamental health benefits, plant isoflavones reveal prospective therapeutic effects that worth further standardized analysis.

In utero exposure to genistein decreased intranasal house dust mite-induced respiratory allergy in middle-aged male B6C3F1 offspring

Despite many hypothesized benefits of dietary isoflavone genistein (GEN) deriving from soy-based products, questions surrounding GEN's developmental effects are increasing. To understand if in utero GEN exposure modulated postnatal respiratory allergies in the middle age, we conducted a time course study in the B6C3F1 offspring (PND 240-330) using a common household allergen (house dust mites: HDM; 10 μg/mouse for PND 240 and 290, and 50 μg/mouse for PND 330, a middle age in mice) following intranasal instillation, a physiological route of allergen exposure. GEN was administered to dams by gavage from gestational day 14 to parturition at a physiologically relevant dose (20 mg/kg body weight). Female and male offspring were sensitized with HDM allergens beginning about one month prior to sacrifice followed by challenges with three weekly dosings of HDM extracts, and they were euthanized at day 3 following the final HDM exposure. In utero exposure to GEN decreased HDM allergen-induced respiratory allergy in male B6C3F1 offspring at PND 330 as reflected by decreases in airway hyperresponsiveness (e.g., Penh value), HDM-specific IgG₁ (a Th2 type Ab) and the activity of eosinophil peroxidase in the lung (an indication of eosinophil recruitment to the lungs). However, in utero exposure to GEN had minimal effects on HDM allergen-induced respiratory allergy in the middle-aged female offspring. Changes in serum total IgE, HDM-specific IgE, and lung histopathology scores in both male and female offspring were not biologically significant. Overall, in utero GEN exposure exerted a protective effect on respiratory allergy in the middle-aged male, but not female, B6C3F1 offspring following later-life HDM exposures.

RNA Expression Profile and Alternative Splicing Signatures of Genistein-Treated Breeder Hens Revealed by Hepatic Transcriptomic Analysis

Little information has been available about the influence of dietary genistein (GEN) on hepatic transcriptome of laying broiler breeder (LBB) hens. The study is aimed at broadening the understanding of RNA expression profiles and alternative splicing (AS) signatures of GEN-treated breeder hens and thereby improving laying performance and immune function of hens during the late egg-laying period. 720 LBB hens were randomly allocated into three groups with supplemental dietary GEN doses (0, 40 mg/kg, and 400 mg/kg). Each treatment has 8 replicates of 30 birds. Dietary GEN enhanced the antioxidative capability of livers, along with the increased activities of glutathione peroxidase and catalase. Furthermore, it improved lipid metabolic status and apoptotic process in the liver of hens. 40 mg/kg dietary GEN had the better effects on improving immune function and laying performance. However, transcriptome data indicated that 400 mg/kg dietary GEN did negative regulation of hormone biosynthetic process. Also, it upregulated the expressions of EDA2R and CYR61 by the Cis regulation of neighbouring genes (lncRNA_XLOC_018890 and XLOC_024242), which might activate NF-κB and immune-related signaling pathway. Furthermore, dietary GEN induced AS events in the liver, which also enriched into immune and metabolic process. Therefore, the application of 40 mg/kg GEN in the diet of breeder hens during the late egg-laying period can improve lipid metabolism and immune function. We need to pay attention to the side-effects of high-dose GEN on the immune function.

Effects of High-Dose Genistein on the Hypothalamic RNA Profile and Intestinal Health of Female Chicks

Genistein is abundant in animal feed. In this study, the side effects of high-dose genistein on intestinal health and hypothalamic RNA profile were evaluated. Chicks exposed to high-dose genistein by intraperitoneal injection (416 ± 21, 34.5 ± 2.5) and feed supplementation (308 ± 19, 27.2 ± 2.1) both showed a reduced body weight gain and feed intake in comparison with the control group (261 ± 16, 22.7 ± 1.6, P < 0.01). In comparison with the control (22.4 ± 0.5, 33.3 ± 2.4), serum levels of albumin and total protein were decreased after high-dose genistein injection (21.6 ± 0.5, 31.8 ± 1.6) and diet supplementation (20.6 ± 0.9, 29.9 ± 2.5, P < 0.001). Interestingly, the genistein diet presented the chick hypothalamus with downregulated expression of bitter receptors (TAS1R3, P < 0.05). Meanwhile, it upregulated the expressions of TAS2R1 (P < 0.05) and downstream genes (PLCB2 and IP3R3) in the ileum (P < 0.05). Accordingly, high-dose dietary genistein reduced villus height and the abundance of Lactobacillus, along with the increased abundance of pathogenic bacteria in the ileum (P < 0.05). Furthermore, transcriptomic analysis identified 348 differently expressed genes (168 upregulated and 224 downregulated) in the high-dose dietary genistein treated group in comparison with the control (P < 0.05, |log2FoldChange| > 0.585). Therefore, high-dose dietary genistein altered the hypothalamic RNA profile and signal processing. Cluster analysis further revealed that high-dose dietary genistein significantly influenced apoptosis, the immune process, and the whole synthesis of steroid hormones in the hypothalamus (P < 0.05). In conclusion, high-dose dietary genistein altered the hypothalamic RNA profile and intestinal health of female chicks.

Exacerbation of Type 1 Diabetes in Perinatally Genistein Exposed Female Non-Obese Diabetic (NOD) Mouse Is Associated With Alterations of Gut Microbiota and Immune Homeostasis

Despite various hypothesized benefits of dietary isoflavone genistein (GEN) from soy-based products, many questions surrounding GEN's immunotoxic effects, especially during perinatal exposure, have yet to be answered. The objective of the study was to determine if there existed a sex-specific effect of GEN on type 1 diabetes (T1D) following perinatal exposure. We exposed offspring of non-obese diabetic (NOD) mice to GEN per oral at a physiological dose (20 mg/kg body weight) from embryonic day 7 to postnatal day (PND) 21. In female offspring, perinatal GEN dosing significantly increased the incidence of T1D at early time points, and the exacerbation was associated with decreased serum levels of interleukin (IL)-10, IgG2a, and IgM. In male offspring dosed with GEN, a decrease in serum IgG1 was also observed. Flow cytometric analysis in females suggested an increased pro-inflammatory splenic CD5+CD24- and CD4-CD8+ cell counts, while both %T cells and %CD4+ T cells were significantly decreased in males, suggesting an anti-inflammatory effect. Gut microbiota (GMB) analysis indicated that fecal microbiota from PND 90 female offspring exhibited an increased level of Enterobacteriales (suggesting a pro-inflammatory response), while the similar changes were not found in PND 30 females. Moreover, RNA sequencing showed that intestinal α-defensin expression was down-regulated in GEN-treated females, supporting a pro-inflammatory response. However, perinatal GEN administration perturbed GMB toward an anti-inflammatory response in PND 90 males. Taken together, a strong sex-specific effect was found in the perinatal GEN exposure window, and the T1D exacerbation in NOD females was associated with GMB-related immunomodulatory mechanisms.

Biochemistry and use of soybean isoflavones in functional food development

Soybeans and their food products exist in the market in various forms, ranging from crude oils and bean meals to nutritious products (e.g. soy milk powers). With the availability of technologies for mass production of soy products and for enrichment of soy components (e.g. phospholipids, saponins, isoflavones, oligosaccharides and edible fiber), the nutritional values of soy products have been enhanced remarkably, offering the potential for functional food development. Among different bioactive components in soybeans, one important component is isoflavones, which have been widely exploited for health implications. While there are studies supporting the health benefits of isoflavones, concerns on adverse effects have been raised in the literature. The objective of this article is to review the recent understanding of the biological activities, adverse effects, and use of isoflavones in functional food development.

The association between urinary genistein levels and mortality among adults in the United States

Background

Current research on the relationship between phytoestrogens and mortality has been inconclusive. We explored the relationship between genistein, a phytoestrogen, and mortality in a large cohort representative of the United States population.

Methods

Data were analyzed from the National Health and Nutrition Examination Survey (NHANES) from 1999–2010. Normalized urinary genistein (nUG) was analyzed as a log-transformed continuous variable and in quartiles. Mortality data were obtained from the National Death Index and matched to the NHANES participants. Survival analyses were conducted using the Kaplan-Meier analysis. Cox proportional hazard models were constructed for all-cause and cause-specific mortality without and with adjustment for potential confounding variables.

Results

Of 11,497 participants, 944 died during the 64,443 person-years follow-up. The all-cause mortality rate was significantly lower in the lowest quartile compared to the highest quartile (incidence rate ratio = 2.14, 95%CI = 1.76 to 2.60). Compared to the lowest quartile, the highest quartile had significantly higher adjusted all-cause (HR = 1.57, 95%CI = 1.23 to 2.00), cardiovascular (HR = 1.67, 95%CI = 1.04 to 2.68), and other-cause (HR = 1.85, 95%CI = 1.33 to 2.57) mortality.

Conclusion

We found that high urinary genistein levels were associated with increased risk of all-cause, cardiovascular, and other-cause mortality. This is contrary to popular opinion on the health benefits of genistein and needs further research.

Methoxychlor metabolite HPTE alters viability and differentiation of embryonic thymocytes from C57BL/6 mice

Endocrine-disrupting chemicals (EDC) are widespread in the built and natural environments. Heightened public awareness of their potential danger has led to concern about whether EDC and their metabolites have significant negative biological effects. Studies have shown that EDC like DDT and other organochlorine pesticides, such as methoxychlor (MXC), have adverse effects on immune cells, but no studies have addressed the impact of HPTE, the primary metabolite of MXC. To elucidate the presence and significance of HPTE adverse effects, this study explored the impact of HPTE on a critical window and component of immune system development, embryonic T-cell development. Lesions at this phase of development can lead to lifelong immune dysfunction and increased incidence of immune disease, such as autoimmunity. Embry-onic thymocytes (GD 16-18) from C57BL/6 mice were subjected to an in vitro differentiation culture that mimicked early steps in thymocyte development in the presence of 0.005, 0.05, 0.5, 5, or 50 μM HPTE, or a model endocrine disruptor, DES. The results indicated that compared to the vehicle control, HPTE- and DES-induced death of thymocytes. Annexin-V staining and Caspase 8, markers of programed cell death, revealed that the loss of cells was due at least in part to induction of apoptosis. Moreover, HPTE-induced cell death not only resulted in selective loss of double positive thymocytes, but also loss of developing CD4 intermediate cells (post-double positive partially differentiated thymocyte population). Phenotypic analysis of thymocyte maturation (T-cell receptor, TCR) and TCR ligation (CD5) surface markers revealed that surviving embryonic thymocytes expressed low levels of both. Taken together these data demonstrate that immature embryonic thymocytes are sensitive to HPTE exposure and that HPTE exposure targets thymocyte populations undergoing critical differentiation steps. These findings suggest HPTE may play a pivotal role in MXC exposure-induced immune dysfunction.

Soy-Based Infant Formula: Are Phyto-Oestrogens Still in Doubt?

Although Scientific Societies have stated that there are very few indications for the use of soy-based formula (SF) in infant nutrition, their utilization rates have been repeatedly found to be higher than expected. It is likely that a significant role in this regard is played by the belief that the use of SF during infancy can reduce the risk of the development of several diseases later in life. Although no definitive data that can substantiate these claims have been collected, many people perceive soy consumption to confer significant health benefits and might also use soy for infant nutrition. However, not all the problems regarding safety of SF in infants have been definitively solved. Among risks, the potentially toxic role of the phyto-oestrogens contained in SF is not definitively established. In vitro and animal studies have raised suspicions that SF could have potentially negative effects on sexual development and reproductive function, neurobehavioral development, immune function, and thyroid function. Several studies in humans have aimed to assess whether the results of animal studies can be applied to humans and whether SF can be used in infants following the official recommendations. The results are somewhat conflicting. The aim of this narrative review is to discuss what is presently known regarding the impact of phyto-oestrogens in SF on early and late child development. PubMed was used to search for the studies published from January 1980 to June 2017 using the keywords: “soy,” “soy formula,” “child,” “phytoestrogens.” Analysis of the literature showed that a global evaluation of the impact of modern SFs on human development seems to suggest that their use is not associated with relevant abnormalities. Only children with congenital hypothyroidism need adequate monitoring of thyroid function.

Dietary genistein supplementation for breeders and their offspring improves the growth performance and immune function of broilers

Genistein (GEN) is mainly extracted from soy plants and has potential functions as an antioxidant and in promoting immune function and growth. This study evaluated the effects of feeding breeders and their offspring dietary GEN on the immune function and growth performance of broiler chicks. Breeders were assigned to a control diet or GEN diet (control diet +400 mg/kg GEN), and their offspring were fed a control diet or GEN diet (control diet +40 mg/kg GEN). GEN treatment increased the body weight gain, tibial length, tibial width and slaughter performance of broilers and decreased the feed conversion ratio. The treatment also affected skeletal muscle myosin assembly and growth and increased growth hormone levels and IGF-I and IGFBP1 expression. Following GEN treatment, antigen processing and presentation, macrophage activation, B lymphocyte, NK cell and helper T cell proliferation, and CD4+ T lymphocyte differentiation all increased significantly. Increases were also observed in IgM and IgG concentrations, antibody titers, and antioxidant capacity. In addition, GEN treatment activated the Toll-like receptor signaling pathway and MAPK cascade signaling pathway. In summary, dietary GEN supplementation for breeders and their offspring can improve the growth performance and immune function of broiler chicks.

Dietary soy isoflavones during pregnancy suppressed the immune function in male offspring albino rats

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Less attention has been paid to the immune effects of phytoestrogens during pregnancy on the first generation.

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Soy isoflavones fed to pregnant rats could modulate the immune response of the male offspring.

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Isoflavones reduced spleen and thymus weights in rats born to dams fed dietary soy.

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Soy isoflavones possibly mediated its effect through reduction of IFN-γ that interacts with the IL-12 production pathway.

Phytoestrogens have an impact on both animals and humans due to use of legumes in animal diets as well as the increase of vegetarian diets in some human populations. Phytoestrogens thought to have varieties of adverse effects, among which immune system was involved. The present study aimed to investigate the effect of prenatal exposure to dietary soy isoflavones on some immunological parameters in male albino rat offspring. The pregnant rats were divided to three groups (12/group). Control group (free soy isoflavones), low soy isoflavones group (6.5%) and high soy isoflavones group (26%). The male offspring cell-mediated immune response was determined using phytohemagglutinin (PHA) injection and the intumesce index which was calculated on postnatal day 50 (PND 50). At PND 50, blood samples were collected for interleukin 12 (IL-12), interferon γ (IFN-γ) and tumor necrosis factor α (TNF-α) determination. Spleen, thymus, and PHA injected footpads were fixed for histopathology. Intumesce index, IL-12, IFN-γ, spleen and thymus relative weights were significantly (P < 0.05) decreased in offspring born to dams fed low and high dietary soy isoflavones. In contrary, TNF-α was significantly (P < 0.05) increased in offspring born to dams fed high dietary soy isoflavones. Spleen of rats born to dams fed high dose of dietary soy isoflavones showed coagulative necrosis in white pulp. In conclusion, male offspring born to dams fed different levels of soy isoflavones showed marked immunosuppression after PHA stimulation. This effect was mediated through the reduced IFN-γ that interacts with the IL-12 production pathway.

Effects of Salvia miltiorrhiza extract with supplemental liquefied calcium on osteoporosis in calcium-deficient ovariectomized mice

Background

Extracts from Salvia miltiorrhiza Bunge have been used in traditional Asian medicine to treat coronary heart disease, chronic renal failure, atherosclerosis, myocardial infraction, angina pectoris, myocardial ischemia, dysmenorrheal, neurasthenic insomnia, liver fibrosis and cirrhosis. The aim of the study was to investigate the anti-RANK signal effect of the combination of S.miltiorrhiza Bunge (SME) and liquefied calcium (LCa) supplement with ovariectomized (OVX-SML) mice, a osteoporosis animal model. Results were compared to 17β-estradiol (E₂) treatment.

Methods

A total of 70 female ICR strain mice (7 weeks) were randomly divided into 10 groups with 7 mice in each group as follows: (1) sham-operated control mice (sham) received daily oral phosphate-buffered-saline (PBS) of equal volumes through oral administration. (2) OVX mice received a daily oral administration of PBS (OVX). (3) OVX mice treated daily with 50 mg/kg b.w./ day of SME (4) with 100 mg/kg b.w./day of SME or (5) with 200 mg/kg b.w./day of SME via oral administration. (6) OVX mice treated daily with 50 mg/kg b.w./day of SML (7) with 100 mg/kg b.w./day of SML or (8) with 200 mg/kg b.w./day of SML via oral administration. (9) OVX mice treated daily with 10 ml/kg b.w./day of LCa (10) OVX mice received i.p. injections of 17β-estradiol (E₂) (0.1 mg/kg b.w./day) three times per week for 12 weeks.

Results

micro-CT analysis revealed that oral administration of SML inhibited tibial bone loss, sustained trabecular bone state, and ameliorated bone biochemical markers. In addition, SML administration compared to SEM and LCa reduced serum levels of RANKL, osteocalcin and BALP through increased serum levels of OPG and E₂ in OVX mice. SML also had more beneficial effects on protection of estrogen-dependent bone loss through blocking expression of TRAF6 and NFTAc1 and produces cathepsin K and calcitonin receptor to develop osteoclast differentiation.

Conclusion

These data suggest that S. miltiorrhiza Bunge combined with liquefied calcium supplement has an inhibitory activity in OVX mice. This result implies the possibility of a pharmacological intervention specifically directed toward a disease such as osteoporosis where decreased bone strength increases the risk of a broken bone.

Electronic supplementary material

The online version of this article (10.1186/s12906-017-2047-y) contains supplementary material, which is available to authorized users.

Hypotensive effects of genistein: From chemistry to medicine

Genistein (4', 5, 7-trihydroxyisoflavone), a naturally occurring flavonoid characteristic of Leguminoseae plants, is a phyto-oestrogen exerting oestrogenic activity as both an agonist and an antagonist substance. A large body of evidence suggests that genistein possesses many physiological and pharmacological properties that make this molecule a potential agent for the prevention and treatment of a number of chronic diseases. Growing evidence suggests that genistein could act as a vasodilating, anti-thrombotic, and anti-atherosclerotic agent, exerting these effects through different mechanisms of action. This paper aims to review data from the literature assessing the beneficial effects of genistein on hypertension, one of the most important cardiovascular disease risk factors along with hyperglycemia and hyperlidipemia. In addition, we discuss the chemistry, main sources and bioavailability of genistein. Scientific findings support genistein's potential as a promising anti-hypertensive agent in different experimental models. However, clinical trials are very limited and more research will be required before genistein intake can be recommended as part of therapies targeting raised blood pressure.

Intestinal absorption of iron and calcium from soy and cow's milk-based infant formulas in weanling rats pups

ABSTRACT Objective: This study aimed to compare the intestinal absorption of iron and calcium between soy-based and cow's milk-based infant formulas in weanling rats. Methods: Twenty male Wistar rats, twenty-one days old on the first day of weaning, were used in this experiment, divided in two Groups, one Group was fed soy protein-based infant formula the other, cow's milk protein-based infant formula. During the study period (ten consecutive days) the animals received food and water ad libitum. Hematocrit and hemoglobin were evaluated on the first, fifth, and tenth days by the Wintrobe and cyanomethemoglobin methods. Feces and urine were collected, beginning on the fifth day, for three consecutive days. On the tenth day, hepatic iron content was also analyzed. Hepatic iron as well as fecal and urinary iron and calcium analyses were performed using an atomic absorption spectrophotometer. At thirty-one days of age, the animals were anesthetized with ketamine and xylazine and sacrificed by exsanguination via the vena cava. Results: The final concentration of hemoglobin in the group soy-based infant formula and milk-based infant formula were: 10.3±1.3g/dL and 10.9±1.0g/dL (p=0.310). The apparent absorption of iron and calcium, in that order, were: 73.4±10.2% and 70.2±9.5%; 97.2±0.7% and 97.6±1.0% (p=0.501; p=0.290). The apparent calcium retention was: 88.4% ±2.2 and 88.6±2.6% (p=0.848). Hepatic iron content was: 522.0±121.1mg/g and 527.8±80.5mg/g (p=0.907) . Conclusion: Intestinal iron and calcium absorption from soy-based infant formula is similar to that from milk-based infant formula in weanling rats.

Improvement of Soybean Products Through the Response Mechanism Analysis Using Proteomic Technique

Soybean is rich in protein/vegetable oil and contains several phytochemicals such as isoflavones and phenolic compounds. Because of the predominated nutritional values, soybean is considered as traditional health benefit food. Soybean is a widely cultivated crop; however, its growth and yield are markedly affected by adverse environmental conditions. Proteomic techniques make it feasible to map protein profiles both during soybean growth and under unfavorable conditions. The stress-responsive mechanisms during soybean growth have been uncovered with the help of proteomic studies. In this review, the history of soybean as food and the morphology/physiology of soybean are described. The utilization of proteomics during soybean germination and development is summarized. In addition, the stress-responsive mechanisms explored using proteomic techniques are reviewed in soybean.

Peripubertal ovariectomy influences thymic adrenergic network plasticity in adult rats

The study investigated the influence of peripubertal ovariectomy on the thymic noradrenaline (NA) concentration, and the thymocyte NA content and β2- and α1-adrenoceptor (AR) expression in adult 2- and 11-month-old rats. In control rats, the thymic NA concentration increased with age. This increase reflected rise in the density of catecholamine (CA)-containing fluorescent nerve fibers and cells and their CA content. Additionally, the average β2- and α1-AR thymocyte surface density changed in the opposite direction with age; the density of β2-AR decreased, whereas that of α1-AR increased. Ovariectomy diminished the thymic NA concentration in 2-month-old rats. This reflected the decrease in the density of fluorescent nerve fibers, and CA content in fluorescent nerve fibers and non-lymphoid cells, since the thymocyte NA content was increased in ovariectomized (Ox) rats. Estrogen supplementation prevented the ovariectomy-induced changes. In Ox rats, the density of CA-synthesizing nerve fibers and non-lymphoid cells diminished with age. To the contrary, NA content in thymocytes increased with age, but it did not exceed that in 11-month-old controls. Additionally, ovariectomy diminished the average thymocyte surface density of β2-ARs, but it increased that of α1-ARs in 2-month-old-rats (due to estrogen, and estrogen and progesterone deficiency, respectively). These changes, despite of the rise in circulating estrogen level post-ovariectomy, remained stable with age. This most likely reflected a decreased sensitivity to estrogen action, as a consequence of the hormone misprinting in peripubertal age. The analysis of thymocyte proliferation in culture suggested that age- and ovariectomy-induced alterations in thymocyte NA synthesis and AR expression altered NA autocrine/paracrine action on thymocytes. In conclusion, the study indicates that the ovarian hormone deficiency in peripubertal age affects ovarian steroid-dependent remodeling of thymic adrenergic regulatory network in adult rats.

Soy isoflavone intake is associated with risk of Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis affecting children. Incidence of KD varies according to ethnicity and is highest in Asian populations. Although genetic differences may explain this variation, dietary or environmental factors could also be responsible. The objectives of this study were to determine dietary soy and isoflavone consumption in a cohort of KD children just before disease onset and their mothers' intake during pregnancy and nursing. We tested the hypothesis that soy isoflavone consumption is associated with risk of KD in US children, potentially explaining some of the ethnic-cultural variation in incidence. We evaluated soy food intake and isoflavone consumption in nearly 200 US KD cases and 200 age-matched controls using a food frequency questionnaire for children and in their mothers. We used a logistic regression model to test the association of isoflavones and KD. Maternal surveys on soy intake during pregnancy and nursing showed no significant differences in isoflavone consumption between groups. However, we identified significantly increased KD risk in children for total isoflavone (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.37-3.96) and genistein (OR, 2.46; 95% CI, 1.46-4.16) intakes, when comparing high soy consumers vs nonconsumers. In addition, significantly increased KD risk occurred in Asian-American children with the highest consumption (total isoflavones: OR, 7.29; 95% CI, 1.73-30.75; genistein: OR, 8.33; 95% CI, 1.92-36.24) compared to whites. These findings indicate that childhood dietary isoflavone consumption, but not maternal isoflavone intake during pregnancy and nursing, relates to KD risk in an ethnically diverse US population.

Membrane-Localized Estrogen Receptor 1 Is Required for Normal Male Reproductive Development and Function in Mice

Estrogen receptor 1 (ESR1) mediates major reproductive functions of 17β-estradiol (E2). Male Esr1 knockout (Esr1KO) mice are infertile due to efferent ductule and epididymal abnormalities. The majority of ESR1 is nuclear/cytoplasmic; however, a small fraction is palmitoylated at cysteine 451 in mice and localized to cell membranes, in which it mediates rapid E2 actions. This study used an Esr1 knock-in mouse containing an altered palmitoylation site (C451A) in ESR1 that prevented cell membrane localization, although nuclear ESR1 was expressed. These nuclear-only estrogen receptor 1 (NOER) mice were used to determine the roles of membrane ESR1 in males. Epididymal sperm motility was reduced 85% in 8-month-old NOER mice compared with wild-type controls. The NOER mice had decreased epididymal sperm viability and greater than 95% of sperm had abnormalities, including coiled midpieces and tails, absent heads, and folded tails; this was comparable to 4-month Esr1KO males. At 8 months, daily sperm production in NOER males was reduced 62% compared with controls. The NOER mice had histological changes in the rete testes, efferent ductules, and seminiferous tubules that were comparable with those previously observed in Esr1KO males. Serum T was increased in NOER males, but FSH, LH, and E2 were unchanged. Critically, NOER males were initially subfertile, becoming infertile with advancing age. These findings identify a previously unknown role for membrane ESR1 in the development of normal sperm and providing an adequate environment for spermatogenesis.

Isoflavones: Anti-Inflammatory Benefit and Possible Caveats

Inflammation, a biological response of body tissues to harmful stimuli, is also known to be involved in a host of diseases, such as obesity, atherosclerosis, rheumatoid arthritis, and even cancer. Isoflavones are a class of flavonoids that exhibit antioxidant, anticancer, antimicrobial, and anti-inflammatory properties. Increasing evidence has highlighted the potential for isoflavones to prevent the chronic diseases in which inflammation plays a key role, though the underlying mechanisms remain unclear. Recently, some studies have raised concerns about isoflavones induced negative effects like carcinogenesis, thymic involution, and immunosuppression. Therefore, this review aims to summarize the anti-inflammatory effects of isoflavones, unravel the underlying mechanisms, and present the potential health risks.

Roles of Dietary Phytoestrogens on the Regulation of Epithelial-Mesenchymal Transition in Diverse Cancer Metastasis

Epithelial-mesenchymal transition (EMT) plays a key role in tumor progression. The cells undergoing EMT upregulate the expression of cell motility-related proteins and show enhanced migration and invasion. The hallmarks of EMT in cancer cells include changed cell morphology and increased metastatic capabilities in cell migration and invasion. Therefore, prevention of EMT is an important tool for the inhibition of tumor metastasis. A novel preventive therapy is needed, such as treatment of natural dietary substances that are nontoxic to normal human cells, but effective in inhibiting cancer cells. Phytoestrogens, such as genistein, resveratrol, kaempferol and 3,3′-diindolylmethane (DIM), can be raised as possible candidates. They are plant-derived dietary estrogens, which are found in tea, vegetables and fruits, and are known to have various biological efficacies, including chemopreventive activity against cancers. Specifically, these phytoestrogens may induce not only anti-proliferation, apoptosis and cell cycle arrest, but also anti-metastasis by inhibiting the EMT process in various cancer cells. There have been several signaling pathways found to be associated with the induction of the EMT process in cancer cells. Phytoestrogens were demonstrated to have chemopreventive effects on cancer metastasis by inhibiting EMT-associated pathways, such as Notch-1 and TGF-beta signaling. As a result, phytoestrogens can inhibit or reverse the EMT process by upregulating the expression of epithelial phenotypes, including E-cadherin, and downregulating the expression of mesenchymal phenotypes, including N-cadherin, Snail, Slug, and vimentin. In this review, we focused on the important roles of phytoestrogens in inhibiting EMT in many types of cancer and suggested phytoestrogens as prominent alternative compounds to chemotherapy.

Prenatal Exposure to Soy Isoflavones Altered the Immunological Parameters in Female Rats

Information on the effects of phytoestrogens on animals has increased recently; however, there were only few studies on prenatal exposure on cellular immune response. Pregnant rats were assigned to 3 groups (12 rats per group), the first was fed control diet, the second was fed low-dose (6.5 g/100 g of diet) soy isoflavones, while the third was fed high-dose (26 g/100 g of diet) soy isoflavones. The female offspring cell-mediated immune response was determined using phytohemagglutinin (PHA) injection, and intumesce index was calculated on postnatal day 50. After 24 hours of PHA injection, blood samples were collected for tumor necrosis factor α, interferon γ (IFN-γ), and interleukin (IL)-12 determination. Spleen, thymus, and PHA-injected footpads were fixed for histopathology. Intumesce index was significantly (P < 0.05) reduced in rats' offspring born from dams fed low- and high-dietary soy isoflavones than that in control groups. Thymic relative weights in offspring of rats fed high-dietary soy isoflavones showed a significant (P < 0.05) decrease compared to that in the control group. Female offspring where low and high-dietary soy isoflavones were fed to their dams showed a significant (P < 0.05) decrease in IFN-γ and IL-12 than that in control ones. Spleen of rats born from dams fed high dose of dietary soy isoflavones showed lymphocytic depletion in white pulp. Taking together, it is clear that dietary soy isoflavones at prenatal period had immunosuppressive effect on female offspring after PHA stimulation. This effect was mediated through reduced IFN-γ that interplayed in IL-12 production pathway thus reducing its level.

In Utero exposure to genistein enhanced intranasal house dust mite allergen-induced respiratory sensitization in young adult B6C3F1 mice

Despite many hypothesized benefits of dietary isoflavone genistein (GEN) deriving from soy-based products, questions surrounding GEN's developmental immunotoxic effects are increasing. To understand how in utero GEN exposure may modulate postnatal respiratory sensitization, we conducted a time course study using a common household allergen (house dust mites: HDM; 10μg/mouse) following intranasal instillation, a physiological route of allergen exposure. GEN was administered to dams by gavage from gestational day 14 to parturition at a physiologically relevant dose (20mg/kg bw). Female and male offspring were sensitized with HDM allergens beginning about one month prior to sacrifice followed by challenges with three weekly doses of HDM extracts, and they were euthanized at day 3 following the final HDM exposure at four different time points (postnatal day (PND) 80, 120, 160, and 200). In utero GEN combined with postnatal HDM exposures (GEN+HDM) increased total IgE production in both young female and male B6C3F1 offspring (e.g., PND 80 in females and PND 120 in males). Increased antigen-specific IgG1, IgG2a and IgG2b levels were also observed at various time points in both female and male offspring. In addition, increases in macrophage number in bronchoalveolar lavage fluid of both female and male GEN+HDM offspring at PND 80 and PND 120, respectively, were observed when compared to the vehicle group. For T cells, an increase over the vehicle in female GEN+HDM offspring was observed at PND 80. Due to similar patterns of increases, it seems likely that GEN+HDM-induced increases in total IgE and macrophages are related. Overall, in utero GEN plus later-life HDM exposures exert increases in total IgE and HDM-specific IgG production as well as macrophage recruitments to the lung in young adult mice.

Contributions of nonhematopoietic cells and mediators to immune responses: implications for immunotoxicology

Immunotoxicology assessments have historically focused on the effects that xenobiotics exhibit directly on immune cells. These studies are invaluable as they identify immune cell targets and help characterize mechanisms and/or adverse outcome pathways of xenobiotics within the immune system. However, leukocytes can receive environmental cues by cell-cell contact or via released mediators from cells of organs outside of the immune system. These organs include, but are not limited to, the mucosal areas such as the lung and the gut, the liver, and the central nervous system. Homeostatic perturbation in these organs induced directly by toxicants can initiate and alter the outcome of local and systemic immunity. This review will highlight some of the identified nonimmune influences on immune homeostasis and provide summaries of how immunotoxic mechanisms of selected xenobiotics involve nonimmune cells or mediators. Thus, this review will identify data gaps and provide possible alternative mechanisms by which xenobiotics alter immune function that could be considered during immunotoxicology safety assessment.

Genistein decreases basal hepatic cytochrome P450 1A1 protein expression and activity in Swiss Webster mice

Soy consumption has been associated with risk reduction for chronic diseases such as cancer. One proposed mechanism for cancer prevention by soy is through decreasing cytochrome P450 1A1 (Cyp1a1) activity. However, it is not known with certainty which soy components modulate Cyp1a1, or the characteristics or mechanisms involved in the responses after short-term (<20 days) dietary treatment without concomitant carcinogen-mediated induction. Therefore, the objective was to test the hypothesis that physiologic concentrations of dietary genistein and/or daidzein will decrease basal hepatic Cyp1a1 protein expression and activity in male and female Swiss Webster mice via inhibiting the bindings of aryl hydrocarbon receptor (AhR)-AhR nuclear translocator (ARNT) and estrogen receptor-α to the Cyp1a1 promoter region xenobiotic response element. The mice were fed the AIN-93G diet supplemented with 1500 mg/kg of genistein or daidzein for up to 1 week. Genistein, but not daidzein, significantly decreased basal hepatic microsomal Cyp1a1 protein expression and activity. AhR protein expression was not altered. Molecular mechanisms were investigated in Hepa-1c1c7 cells treated with 5 μmol/L purified aglycones genistein, daidzein, or equol. Cells treated with genistein exhibited inhibitions in ARNT and estrogen receptor-α bindings to the Cyp1a1 promoter region. This study demonstrated that genistein consumption reduced constitutive hepatic Cyp1a1 protein expression and activity, thereby contributing to the understanding of how soy isoflavone aglycones modulate cytochrome P450 biotransformation enzymes.

Consumption of soy isoflavone enriched bread in men with prostate cancer is associated with reduced proinflammatory cytokines and immunosuppressive cells

We hypothesized that soy phytochemicals may have immunomodulatory properties that may affect prostate carcinogenesis and progression. A randomized, phase II trial was conducted in 32 patients with prostate cancer with asymptomatic biochemical recurrence but no measurable disease on standard staging studies. Patients were randomized to two slices of soy bread (34 mg isoflavones/slice) or soy bread containing almond powder daily as a source of β-glucosidase. Flow cytometry and bioplex assays were used to measure cytokines or immune cell phenotype in blood at baseline (day 0) and following intervention (day 56). Adequate blood samples were available at enrollment and day 56 and evaluated. Multiple plasma cytokines and chemokines were significantly decreased on day 56 versus baseline. Subgroup analysis indicated reduced TH1 (P = 0.028) and myeloid-derived suppressor cell (MDSC)-associated cytokines (P = 0.035). TH2 and TH17 cytokines were not significantly altered. Phenotypic analysis revealed no change in CD8(+) or CD4(+) T cells but showed increased CD56(+) natural killer (NK) cells (P = 0.038). The percentage of cells with a T regulatory cell phenotype (CD4(+)CD25(+)FoxP3(+)) was significantly decreased after 56 days of soy bread (P = 0.0136). Significantly decreased monocytic (CD33(+)HLADR(neg)CD14(+)) MDSC were observed in patients consuming soy bread (P = 0.0056). These data suggest that soy bread modulates systemic soluble and cellular biomarkers consistent with limiting inflammation and suppression of MDSCs. Additional studies to elucidate impact on the carcinogenic process or as a complement to immune-based therapy are required.

Effects of flavonoids on expression of genes involved in cell cycle regulation and DNA replication in human fibroblasts

Flavonoids have been studied as potential agents in medicine for many years. Among them, genistein was found to be active in various biological systems, mainly in prevention of cancer. Our recent work supported the idea that genistein also impacts multiple cellular processes in healthy fibroblasts; however, its effects on cell cycle-related pathways remained to be elucidated. Thus, in this work, high throughput screening with microarrays coupled to real-time quantitative Reverse Transcription PCR analyses was employed to study the changes in expression of key genes associated with cell cycle regulation and/or DNA replication in response to genistein, kaempferol, daidzein, and mixtures of genistein and either kaempferol or daidzein. Among them, genistein was found as the most significantly modulating, in a time- and dose-dependent manner, compound of activity of studied genes, whose products are involved in different phases of the cell cycle and/or in regulatory processes important for DNA replication and cell growth. It considerably reduced the efficiency of expression of genes coding for MCM2-7 and MCM10 helicases, as well as some other proteins involved in the S phase control. In addition, genistein caused cell cycle arrest in the G2/M phase, which was accompanied by activation of CDKN1A, CDKN1C, CDKN2A, CDKN2B, CDKN2C, and GADD45A genes, as well as down-regulation of several mRNAs specific for this stage, demonstrated by transcriptomic assessments. We believe that studies described in this paper will be helpful in elucidating molecular mechanisms of action of genistein as modulator of cell cycle and inhibitor of DNA replication in humans.

Thymocyte Differentiation is Regulated by a Change in Estradiol Levels during the Estrous Cycle in Mouse

Recent study showed that T cells in the immune organs and peripheral blood are influenced by estradiol, leading to a dysfunction of the immune system. However, little is known about the thymic-gonadal relationship during the estrous cycle in mouse. Therefore, the purpose of this study was to elucidate the mechanism by which a change in estradiol levels during the estrous cycle regulates the development of T cells in the mouse thymus. Six-week-old ICR mice were used and divided into four groups, including diestrous, proestrous, estrous, and metestrous. We first confirmed that ER-α and - β estrogen receptors were expressed in thymic epithelial cells, showing that their expression was not different during the estrous cycle. There was also no significant difference in thymic weight and total number of thymocytes during the estrous cycle. To determine the degree of thymocyte differentiation during the estrous cycle, we analyzed thymocytes by flow cytometry. As a result, the percentage of CD4+CD8+ double-positive (DP) T cells was significantly decreased in the proestrous phase compared to the diestrous phase. However, CD4+CD8- or CD4-CD8+ (SP) T cells were significantly increased in the proestrous phase compared to the diestrous phase. In addition, the percentage of CD44+CD25- (DN1) T cells was significantly decreased in the estrous phase compared to other phases, whereas the percentages of CD44+CD25+ (DN2), CD44-CD25+ (DN3), and CD44-CD25- (DN4) were not changed during the estrous cycle. These results indicate that the development of thymocytes may arrest in the DP to SP transition stage in the proestrous phase displaying the highest serum level of estradiol. This study suggests that a change in estradiol levels during the estrous cycle may be involved in the regulation of thymocyte differentiation in the mouse thymus.

Genistein protects female nonobese diabetic mice from developing type 1 diabetes when fed a soy- and alfalfa-free diet

The objective of this study was to determine the effects of the phytoestrogen genistein (GEN) on the time of onset and/or the incidence of type 1 diabetes (T1D) in female nonobese diabetic (NOD) mice, when administered GEN by gavage once every day for up to 180 days. Five groups of mice (approximately 24 animals/group; 6-7 weeks of age) were included: naive control, vehicle control (25 mM Na2CO3 in water), and 3 GEN treatment groups (2 mg/kg, 6 mg/kg, and 20 mg/kg). Mice were maintained on a soy- and alfalfa-free diet (5K96) during the study and were monitored for blood glucose changes every week. When compared to the vehicle control, exposure to 2-mg/kg GEN produced significant decreases ranging from 55 to 79% in the total incidences of diabetes (blood glucose ≥ 250 mg/dl) and severe diabetes (blood glucose ≥ 400 mg/dl) starting at week 14 of the study. However, during the later stages of the study (i.e., after week 23), the 2-mg/kg dose had no effect on disease incidence. In animals treated with 6-mg/kg and 20-mg/kg GEN, significant decreases in the total incidence of diabetes were observed starting at week 16, while the incidence of severe diabetes was significantly decreased with the changes being observed initially at weeks 18 and 17 for the 6-mg/kg and 20-mg/kg GEN treatment groups, respectively. Several lines of evidence, including histopathological analysis, suggested that GEN protected the pancreas from autoimmune destruction. However, this protective effect of GEN was absent when female NOD mice were maintained on NTP-2000 rodent diet, which contained 5% soybean meal and 7.5% alfalfa meal (the total concentrations of phytoestrogens ranged between 95 and 134 mg/kg). In summary, oral dosing of GEN reduced the incidence and increased the time to onset of T1D in female NOD mice but only when fed a soy- and alfalfa-free diet.

Isoflavones enhance interleukin-17 gene expression via retinoic acid receptor-related orphan receptors α and γ

The retinoic acid receptor-related orphan receptors α and γ (RORα and RORγ), are key regulators of helper T (Th)17 cell differentiation, which is involved in the innate immune system and autoimmune disorders. In this study, we investigated the effects of isoflavones on RORα/γ activity and the gene expression of interleukin (IL)-17, which mediates the function of Th17 cells. In doxycycline-inducible CHO stable cell lines, we found that four isoflavones, biochanin A (BA), genistein, formononetin, and daidzein, enhanced RORα- or RORγ-mediated transcriptional activity in a dose-dependent manner. In an activation assay of the Il17a promoter using Jurkat cells, these compounds enhanced the RORα- or RORγ-mediated activation of the Il17a promoter at concentrations of 1 × 10(-6)M to 1 × 10(-5)M. In mammalian two-hybrid assays, the four isoflavones enhanced the interaction between the RORα- or RORγ-ligand binding domain and the co-activator LXXLL peptide in a dose-dependent manner. In addition, these isoflavones potently enhanced Il17a mRNA expression in mouse T lymphoma EL4 cells treated with phorbol myristate acetate and ionomycin, but showed slight enhancement of Il17a gene expression in RORα/γ-knockdown EL4 cells. Immunoprecipitation and immunoblotting assays also revealed that BA enhanced the interaction between RORγt and SRC-1, which is a co-activator for nuclear receptors. Taken together, these results suggest that the isoflavones have the ability to enhance IL-17 gene expression by stabilizing the interactions between RORα/γ and co-activators. This also provides the first evidence that dietary chemicals can enhance IL-17 gene expression in immune cells.

Genistein modulation of streptozotocin diabetes in male B6C3F1 mice can be induced by diet

Diet and phytoestrogens affect the development and progression of diabetes. The objective of the present study was to determine if oral exposure to phytoestrogen genistein (GE) by gavage changed blood glucose levels (BGL) through immunomodulation in streptozotocin (STZ)-induced diabetic male B6C3F1 mice fed with three different diets. These three diets were: NTP-2000 diet (NTP), soy- and alfalfa-free 5K96 diet (SOF) and high fat diet (HFD) with 60% of kcal from fat, primarily rendered fat of swine. The dosing regimen for STZ consisted of three 100mg/kg doses (i.p.): the first dose was administered at approximately 2weeks following the initiation of daily GE (20mg/kg) gavage, and the second dose was on day 19 following the first dose, and the third dose was on day 57 following the first dose. In mice on the NTP diet, GE treatment decreased BGL with statistical significances observed on days 33 and 82 following the first STZ injection. In mice fed the HFD diet, GE treatment produced a significant decrease and a significant increase in BGL on days 15 and 89 following the first STZ injection, respectively. In mice fed the SOF diet, GE treatment had no significant effects on BGL. Although GE treatment affected phenotypic distributions of both splenocytes (T cells, B cells, natural killer cells and neutrophils) and thymocytes (CD4/CD8 and CD44/CD25), and their mitochondrial transmembrane potential and generation of reactive oxygen species, indicators of cell death (possibly apoptosis), GE modulation of neutrophils was more consistent with its diabetogenic or anti-diabetic potentials. The differential effects of GE on BGL in male B6C3F1 mice fed with three different diets with varied phytoestrogen contents suggest that the estrogenic properties of this compound may contribute to its modulation of diabetes.

Soy promotes juvenile granulosa cell tumor development in mice and in the human granulosa cell tumor-derived COV434 cell line

Soy attracts attention for its health benefits, such as lowering cholesterol or preventing breast and colon cancer. Soybeans contain isoflavones, which act as phytoestrogens. Even though isoflavones have beneficial health effects, a role for isoflavones in the initiation and progression of diseases including cancer is becoming increasingly recognized. While data from rodent studies suggest that neonatal exposure to genistein (the predominant isoflavone in soy) disrupts normal reproductive function, its role in ovarian cancers, particularly granulosa cell tumors (GCT), is largely unknown. Our study aimed to define the contribution of a soy diet in GCT development using a genetically modified mouse model for juvenile GCTs (JGCT; Smad1 Smad5 conditional double knockout mice) as well as a human JGCT cell line (COV434). While dietary soy cannot initiate JGCT development in mice, we show that it has dramatic effects on GCT growth and tumor progression compared to a soy-free diet. Loss of Smad1 and Smad5 alters estrogen receptor alpha (Esr1) expression in granulosa cells, perhaps sensitizing the cells to the effects of genistein. In addition, we found that genistein modulates estrogen receptor expression in the human JGCT cell line and positively promotes cell growth in part by suppressing caspase-dependent apoptosis. Combined, our work suggests that dietary soy consumption has deleterious effects on GCT development.