Phytoestrogen blood levels and adverse outcomes in women with suspected ischemic heart disease

The physiological and biochemical basis of potency thresholds modeled using human estrogen receptor alpha: implications for identifying endocrine disruptors

The endocrine system functions by interactions between ligands and receptors. Ligands exhibit potency for binding to and interacting with receptors. Potency is the product of affinity and efficacy. Potency and physiological concentration determine the ability of a ligand to produce physiological effects. The kinetic behavior of ligand-receptor interactions conforms to the laws of mass action. The laws of mass action define the relationship between the affinity of a ligand and the fraction of cognate receptors that it occupies at any physiological concentration. We previously identified the minimum ligand potency required to produce clinically observable estrogenic agonist effects via the human estrogen receptor-alpha (ERα). By examining data on botanical estrogens and dietary supplements, we demonstrated that ERα ligands with potency lower than one one-thousandth that of the primary endogenous hormone 17β-estradiol (E2) do not produce clinically observable estrogenic effects. This allowed us to propose a Human-Relevant Potency Threshold (HRPT) for ERα ligands of 1 × 10-4 relative to E2. Here, we test the hypothesis that the HRPT for ERα arises from the receptor occupancy by the normal metabolic milieu of endogenous ERα ligands. The metabolic milieu comprises precursors to hormones, metabolites of hormones, and other normal products of metabolism. We have calculated fractional receptor occupancies for ERα ligands with potencies below and above the previously established HRPT when normal circulating levels of some endogenous ERα ligands and E2 were also present. Fractional receptor occupancy calculations showed that individual ERα ligands with potencies more than tenfold higher than the HRPT can compete for occupancy at ERα against individual components of the endogenous metabolic milieu and against mixtures of those components at concentrations found naturally in human blood. Ligands with potencies less than tenfold higher than the HRPT were unable to compete successfully for ERα. These results show that the HRPT for ERα agonism (10-4 relative to E2) proposed previously is quite conservative and should be considered strong evidence against the potential for disruption of the estrogenic pathway. For chemicals with potency 10-3 of E2, the potential for estrogenic endocrine disruption must be considered equivocal and subject to the presence of corroborative evidence. Most importantly, this work demonstrates that the endogenous metabolic milieu is responsible for the observed ERα agonist HRPT, that this HRPT applies also to ERα antagonists, and it provides a compelling mechanistic explanation for the HRPT that is grounded in basic principles of molecular kinetics using well characterized properties and concentrations of endogenous components of normal metabolism.

Heart Failure in Menopause: Treatment and New Approaches

Aging is an important risk factor for the development of heart failure (HF) and half of patients with HF have preserved ejection fraction (HFpEF) which is more common in elderly women. In general, sex differences that lead to discrepancies in risk factors and to the development of cardiovascular disease (CVD) have been attributed to the reduced level of circulating estrogen during menopause. Estrogen receptors adaptively modulate fibrotic, apoptotic, inflammatory processes and calcium homeostasis, factors that are directly involved in the HFpEF. Therefore, during menopause, estrogen depletion reduces the cardioprotection. Preclinical menopause models demonstrated that several signaling pathways and organ systems are closely involved in the development of HFpEF, including dysregulation of the renin-angiotensin system (RAS), chronic inflammatory process and alteration in the sympathetic nervous system. Thus, this review explores thealterations observed in the condition of HFpEF induced by menopause and the therapeutic targets with potential to interfere with the disease progress.

Molecular and cellular outcomes of quercetin actions on healthy and tumor osteoblasts

There is a global trend in the use of natural bioactive compounds to complement conventional therapies in bone diseases. In this work, we studied the effects of the phytoestrogen quercetin (QUE) in healthy and tumor osteoblasts. We found that QUE (1 μM, 48 h) significantly increased the cell number and the viability of healthy human osteoblasts (hFOB cells) determined by a trypan blue and a MTS assay, respectively, among other concentrations tested. In addition, wound healing and cellular adhesion assays also demonstrated that 1 μM of QUE significantly stimulated both parameters in osteoblasts. Moreover, osteoblast differentiation was also triggered by QUE in an osteogenic medium by measuring alkaline phosphatase activity, calcium deposition, and collagen levels. Herein, a concentration of 0.01 μM of QUE showed an increment in these differentiation markers and an activation of AKT/GSK3β/β-catenin pathway, determined by a Western blot analysis. In addition, immunocytochemistry and subcellular fraction studies indicated an increase of β-catenin localization in the plasma membrane after QUE treatment. Otherwise, QUE (20-100 μM) decreased the cell number and the viability in tumor osteoblasts (ROS 17/2.8 cells) after 48 h. Furthermore, QUE (100 μM) decreased AKT(Ser473) and the pro-apoptotic protein BAD(Ser136) phosphorylation. In addition, the ERK1/2 phosphorylation increased leading to osteosarcoma cell death since pre-treatment with the MEK inhibitor PD98059 had reverted QUE effect. Altogether, these results indicate that to stimulate the osteoblastogenesis low concentrations of QUE are required; however, these concentrations are not effective in inhibiting the growth of tumor osteoblasts, for which higher concentrations are required.

Potential Effects of Soy Isoflavones on the Prevention of Metabolic Syndrome

Isoflavones are polyphenols primarily contained in soybean. As phytoestrogens, isoflavones exert beneficial effects on various chronic diseases. Metabolic syndrome increases the risk of death due to arteriosclerosis in individuals with various pathological conditions, including obesity, hypertension, hyperglycemia, and dyslipidemia. Although the health benefits of soybean-derived isoflavones are widely known, their beneficial effects on the pathogenesis of metabolic syndrome are incompletely understood. This review aims to describe the association between soybean-derived isoflavone intake and the risk of metabolic syndrome development. We reviewed studies on soy isoflavones, particularly daidzein and genistein, and metabolic syndrome, using PubMed, ScienceDirect, and Web of Science. We describe the pathological characteristics of metabolic syndrome, including those contributing to multiple pathological conditions. Furthermore, we summarize the effects of soybean-derived daidzein and genistein on metabolic syndrome reported in human epidemiological studies and experiments using in vitro and in vivo models. In particular, we emphasize the role of soy isoflavones in metabolic syndrome-induced cardiovascular diseases. In conclusion, this review focuses on the potential of soy isoflavones to prevent metabolic syndrome by influencing the onset of hypertension, hyperglycemia, dyslipidemia, and arteriosclerosis and discusses the anti-inflammatory effects of isoflavones.

Polyphenolic Profiling of Green Waste Determined by UPLC-HDMSE

Valorising green waste will greatly enhance and promote the sustainable management of this large volume resource. One potential way to achieve this is the extraction of high value human health promoting chemicals (e.g., polyphenols) from this material. Our primary aim was to identify the main polyphenols present in four contrasting green waste feedstocks, namely Smyrnium olusatrum, Urtica dioica, Allium ursinum and Ulex europaeus, using UPLC-HDMSE. Polyphenol-rich Camellia sinensis (green tea) was used as a reference material. Samples were extracted and analysed by UPLC-HDMSE, which was followed by data processing using Progenesis QI and EZ Info. A total of 77 high scoring polyphenolic compounds with reported benefits to human health were tentatively identified in the samples, with abundances varying across the plant types; A. ursinum was seen to be the least abundant in respect to the polyphenols identified, whereas U. europaeus was the most abundant. Important components with a diverse range of bioactivity, such as procyanidins, (−)-epigallocatechin, naringenin, eriodictyol and iso-liquiritigenin, were observed, plus a number of phytoestrogens such as daidzein, glycitin and genistein. This research provides a route to valorise green waste through the creation of nutritional supplements which may aid in the prevention of disease.