Phytoestrogen genistein up-regulates endothelial nitric oxide synthase expression via activation of cAMP response element-binding protein in human aortic endothelial cells

In vitro effects and mechanisms of Humulus lupulus extract on bone marrow progenitor cells and endothelial cells

Osteoporosis is the most common metabolic bone disorder and is associated with a high incidence of fractures. Angiogenesis and adequate blood flow are important during bone repair and maintenance. Estrogens play a key role in bone formation, in the prevention of bone resorption and vasculature maintenance. Hormone replacement therapy (HRT) has been used with great benefits for bone fracture prevention but has been linked to the development of serious important side effects, including cancer and stroke. Phytoestrogens are an attractive alternative to HRT because their chemical structure is similar to estradiol but, they could behave as selective modulators: acting as antagonists of estrogen receptors in the breast and endometrium and as agonists in the vascular endothelium and bone. Hops contain a wide variety of phytoestrogens that have individually been shown to possess estrogenic activity by either blocking or mimicking. In this study we have to evaluate the in vitro effects and mechanisms of action of hops extracts on the osteogenic and adipogenic capacity of bone marrow progenitor cells (BMPCs), and the angiogenic potential of EA.hy926 endothelial cells. We show that hops extracts increase the proliferative capacity of BMPCs and promote their osteogenic differentiation while decreasing their pro-osteoclastogenic capacity; and that these effects are mediated by the MAPK pathway. Additionally, hops extracts prevent the adipogenic differentiation of BMPCs and promote endothelial cell activity, by mechanisms also partially mediated by MAPK.

Anti-cancer mechanisms of natural isoflavones against melanoma

The incidence of skin-related neoplasms has generally increased in recent years. Melanoma arises from malignant mutations in melanocytes in the basal layer of the epidermis and is a fatal skin cancer that seriously threatens human health. Isoflavones are polyphenolic compounds widely present in legumes and have drawn scientists' attention, because they have good efficacy against a variety of cancers, including melanoma, without significant toxic side effects and resistance. In this review article, we summarize the research progress of isoflavones in melanoma, including anti-melanoma roles and mechanisms of isoflavones via inhibition of tyrosinase activity, melanogenesis, melanoma cell growth, invasion of melanoma cells, and induction of apoptosis in melanoma cells. This information is important for the prevention, clinical treatment, and prognosis and survival of melanoma.

The Inverse Association Between Isoflavone Intake and Prevalence of Metabolic Syndrome: A Cross-Sectional Study from National Health and Nutrition Examination Survey

Objective: Metabolic syndrome (MetS) is a global disease burden that has resulted in 10 million people being affected by it, yet no new drugs have been approved for clinical treatment. Isoflavone may be able to stop the development of MetS or enhance its treatment. Therefore, we investigated the relationship between dietary intake of isoflavone and prevalence of MetS to find potentially effective treatments. Methods: We conducted a cross-sectional study using data from 8512 National Health and Nutrition Examination Survey (NHANES) participants from 2007 to 2010 and 2017 to 2018 and their associated isoflavone intake from the flavonoid database in the USDA Food and Nutrient Database for Dietary Studies (FNDDS). We investigated the relationship between MetS status and isoflavone intake by adjusting for confounding variables using multivariable logistic regression models. Results: In a multivariable-adjusted model, there was a negative association between isoflavone intake and the incidence of MetS (odds ratio for Q4 vs. Q1 was 0.66, 95% confidence interval = 0.51-0.86, P = 0.003, p for trend was <0.001). This inverse association remained robust across most subgroups, while nonsignificant interactions were tested between isoflavone intake and age, sex, ethnicity, economic status, body mass index, smoking status, alcohol consumption, and physical activity level (P values for interaction >0.05). Conclusions: We found that MetS prevalence decreased with increased isoflavone intake, suggesting that dietary patterns of soy food or supplement consumption may be a valuable strategy to reduce the disease burden and the prevalence of MetS.

Anti-hypertension effect of Wuwei Jiangya decoction via ACE2/Ang1-7/MAS signaling pathway in SHR based on network degree-distribution analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Wuwei Jiangya decoction (WJD) is a traditional Chinese medicinal formula (Fangji) composed of Gastrodiae Rhizoma, Chuanxiong Rhizoma, Puerariae Lobatae Radix, Cyathulae Radix, and Achyranthis Bidentatae Radix, all of which have been verified to combat hypertension. However, the integrative "shot-gun" mechanism of WJD and its primary active ingredients are still unclear.

AIM OF THE STUDY

To investigate the anti-hypertensive effects of WJD and its originating ingredients.

METHODS

Network-based degree distribution analysis combined with in vivo experiments were performed.

RESULTS

A total of 144 active ingredients in WJD were identified to regulate 84 hypertension-related targets, which are mainly involved in blood pressure and blood vessel diameter regulation. However, for the anti-hypertension effects, "more does not mean better". The majority (76%) of the hubs in the H-network were regulated by no more than four ingredients. We identified 16 primary ingredients that accounted for the therapeutic action against hypertension. For compatibility, the five herbs consistently focused on blood pressure, vascular diameter, and angiogenesis, with the renin-angiotensin system as a primary target. The characteristics of each herb were involved in processes such as lipid localization and oxidative stress, which interact to constitute the regulatory network targeting hypertension, its risk factors, and organ damage. In vivo, WJD significantly reduced systolic blood pressure (SBP), improved left ventricular mass index, and ameliorated cardiac hypertrophy and vascular injury by moderating the renin-angiotensin system via activating the ACE2/Ang-(1-7)/Mas signaling pathway.

CONCLUSION

WJD can lower SBP and ameliorate cardiac hypertrophy and vascular injury through the ACE2/Ang-(1-7)/Mas pathway, thus providing new insights into the development of traditional Chinese medicine as a therapeutic agent for hypertension.

Potential of natural products in combination with arsenic trioxide: Investigating cardioprotective effects and mechanisms

Over the past few decades, clinical trials conducted worldwide have demonstrated the efficacy of arsenic trioxide (ATO) in the treatment of relapsed acute promyelocytic leukemia (APL). Currently, ATO has become the frontline treatments for patients with APL. However, its therapeutic applicability is severely constrained by ATO-induced cardiac side effects. Any cardioprotective agents that can ameliorate the cardiac side effects and allow exploiting the full therapeutic potential of ATO, undoubtedly gain significant attention. The knowledge and use of natural products for evidence-based therapy have grown rapidly in recent years. Here we discussed the potential mechanism of ATO-induced cardiac side effects and reviewed the studies on cardiac side effects as well as the research history of ATO in the treatment of APL. Then, We summarized the protective effects and underlying mechanisms of natural products in the treatment of ATO-induced cardiac side effects. Based on the efficacy and safety of the natural product, it has a promising future in the development of cardioprotective agents against ATO-induced cardiac side effects.

Hydrogen sulfide donor AP123 restores endothelial nitric oxide-dependent vascular function in hyperglycemia via a CREB-dependent pathway

Diabetes is associated with severe vascular complications involving the impairment of endothelial nitric oxide synthase (eNOS) as well as cystathionine γ-lyase (CSE) activity. eNOS function is suppressed in hyperglycaemic conditions, resulting in reduced NO bioavailability, which is paralleled by reduced levels of hydrogen sulfide (H₂S). Here we have addressed the molecular basis of the interplay between the eNOS and CSE pathways. We tested the impact of H₂S replacement by using the mitochondrial-targeted H₂S donor AP123 in isolated vessels and cultured endothelial cells in high glucose (HG) environment, at concentrations not causing any vasoactive effect per se. Aorta exposed to HG displayed a marked reduction of acetylcholine (Ach)-induced vasorelaxation that was restored by the addition of AP123 (10 nM). In HG condition, bovine aortic endothelial cells (BAEC) showed reduced NO levels, downregulation of eNOS expression, and suppression of CREB activation (p-CREB). Similar results were obtained by treating BAEC with propargylglycine (PAG), an inhibitor of CSE. AP123 treatment rescued eNOS expression, as well as NO levels, and restored p-CREB expression in both the HG environment and the presence of PAG. This effect was mediated by a PI3K-dependent activity since wortmannin (PI3K inhibitor) blunted the rescuing effects operated by the H₂S donor. Experiments performed in the aorta of CSE^-/- mice confirmed that reduced levels of H₂S not only negatively affect the CREB pathway but also impair Ach-induced vasodilation, significantly ameliorated by AP123. We have demonstrated that the endothelial dysfunction due to HG involves H₂S/PI3K/CREB/eNOS route, thus highlighting a novel aspect of the H₂S/NO interplay in the vasoactive response.

Dipeptidyl peptidase 4 inhibition rescues PKA-eNOS signaling and suppresses aortic hypercontractility in male rats with heart failure

AIMS

Vascular dysfunction and elevated circulating dipeptidyl peptidase 4 (DPP4) activity are both reported to be involved in the progression of heart failure (HF). While the cardiac benefits of DPP4 inhibitors (DPP4i) have been extensively studied, little is known about the effects of DPP4i on vascular dysfunction in nondiabetic HF. This study tested the hypothesis that vildagliptin (DPP4i) mitigates aortic hyperreactivity in male HF rats.

MATERIALS AND METHODS

Male Wistar rats were subjected to left ventricle (LV) radiofrequency ablation to HF induction or sham operation (SO). Six weeks after surgery, radiofrequency-ablated rats who developed HF were treated with vildagliptin (120 mg⸱kg^-1⸱day^-1) or vehicle for 4 weeks. Thoracic aorta reactivity, dihydroethidium fluorescence, immunoblotting experiments, and enzyme-linked immunosorbent assays were performed.

KEY FINDINGS

DPP4i ameliorated the hypercontractility of HF aortas to the α-adrenoceptor agonist phenylephrine towards SO levels. In HF, the reduced endothelium and nitric oxide (NO) anticontractile effect on phenylephrine response was restored by DPP4i. At the molecular level, this vasoprotective effect of DPP4i was accompanied by (i) reduced oxidative stress and NADPH oxidase 2 (Nox2) expression, (ii) enhanced total endothelial nitric oxide synthase (eNOS) expression and phosphorylation at Ser1177, and (iii) increased PKA activation, which acts upstream of eNOS. Additionally, DPP4i restored the higher serum angiotensin II concentration towards SO.

SIGNIFICANCE

Our data demonstrate that DPP4i ameliorates aortic hypercontractility, most likely by enhancing NO bioavailability, showing that the DPP4i-induced cardioprotection in male HF may arise from effects not only in the heart but also in conductance arteries.

Intertwined associations between oxidative and nitrosative stress and endocannabinoid system pathways: Relevance for neuropsychiatric disorders

The endocannabinoid system (ECS) appears to regulate metabolic, cardiovascular, immune, gastrointestinal, lung, and reproductive system functions, as well as the central nervous system. There is also evidence that neuropsychiatric disorders are associated with ECS abnormalities as well as oxidative and nitrosative stress pathways. The goal of this mechanistic review is to investigate the mechanisms underlying the ECS's regulation of redox signalling, as well as the mechanisms by which activated oxidative and nitrosative stress pathways may impair ECS-mediated signalling. Cannabinoid receptor (CB)1 activation and upregulation of brain CB2 receptors reduce oxidative stress in the brain, resulting in less tissue damage and less neuroinflammation. Chronically high levels of oxidative stress may impair CB1 and CB2 receptor activity. CB1 activation in peripheral cells increases nitrosative stress and inducible nitric oxide (iNOS) activity, reducing mitochondrial activity. Upregulation of CB2 in the peripheral and central nervous systems may reduce iNOS, nitrosative stress, and neuroinflammation. Nitrosative stress may have an impact on CB1 and CB2-mediated signalling. Peripheral immune activation, which frequently occurs in response to nitro-oxidative stress, may result in increased expression of CB2 receptors on T and B lymphocytes, dendritic cells, and macrophages, reducing the production of inflammatory products and limiting the duration and intensity of the immune and oxidative stress response. In conclusion, high levels of oxidative and nitrosative stress may compromise or even abolish ECS-mediated redox pathway regulation. Future research in neuropsychiatric disorders like mood disorders and deficit schizophrenia should explore abnormalities in these intertwined signalling pathways.

The antihypertensive potential of flavonoids from Chinese Herbal Medicine: A review

With the coming of the era of the aging population, hypertension has become a global health burden to be dealt with. Although there are multiple drugs and procedures to control the symptoms of hypertension, the management of it is still a long-term process, and the side effects of conventional drugs pose a burden on patients. Flavonoids, common compounds found in fruits and vegetables as secondary metabolites, are active components in Chinese Herbal Medicine. The flavonoids are proved to have cardiovascular benefits based on a plethora of animal experiments over the last decade. Thus, the flavonoids or flavonoid-rich plant extracts endowed with anti-hypertension activities and probable mechanisms were reviewed. It has been found that flavonoids may affect blood pressure in various ways. Moreover, despite the substantial evidence of the potential for flavonoids in the control of hypertension, it is not sufficient to support the clinical application of flavonoids as an adjuvant or core drug. So the synergistic effects of flavonoids with other drugs, pharmacokinetic studies, clinical trials and the safety of flavonoids are also incorporated in the discussion. It is believed that more breakthrough studies are needed. Overall, this review may shed some new light on the explicit recognition of the mechanisms of anti-hypertension actions of flavonoids, pointing out the limitations of relevant research at the current stage and the aspects that should be strengthened in future researches.

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.

Harnessing polyphenol power by targeting eNOS for vascular diseases

Vascular diseases arise due to vascular endothelium dysfunction in response to several pro-inflammatory stimuli and invading pathogens. Thickening of the vessel wall, formation of atherosclerotic plaques consisting of proliferating smooth muscle cells, macrophages and lymphocytes are the major consequences of impaired endothelium resulting in atherosclerosis, hypercholesterolemia, hypertension, type 2 diabetes mellitus, chronic renal failure and many others. Decreased nitric oxide (NO) bioavailability was found to be associated with anomalous endothelial function because of either its reduced production level by endothelial NO synthase (eNOS) which synthesize this potent endogenous vasodilator from L-arginine or its enhanced breakdown due to severe oxidative stress and eNOS uncoupling. Polyphenols are a group of bioactive compounds having more than 7000 chemical entities present in different cereals, fruits and vegetables. These natural compounds possess many OH groups which are largely responsible for their strong antioxidative, anti-inflammatory antithrombotic and anti-hypersensitive properties. Several flavonoid-derived polyphenols like flavones, isoflavones, flavanones, flavonols and anthocyanidins and non-flavonoid polyphenols like tannins, curcumins and resveratrol have attracted scientific interest for their beneficial effects in preventing endothelial dysfunction. This article will focus on in vitro as well as in vivo and clinical studies evidences of the polyphenols with eNOS modulating activity against vascular disease condition while their molecular mechanism will also be discussed.

Molecular Changes Underlying Genistein Treatment of Wound Healing: A Review

Estrogen deprivation is one of the major factors responsible for many age-related processes including poor wound healing in postmenopausal women. However, the reported side-effects of estrogen replacement therapy (ERT) have precluded broad clinical administration. Therefore, selective estrogen receptor modulators (SERMs) have been developed to overcome the detrimental side effects of ERT on breast and/or uterine tissues. The use of natural products isolated from plants (e.g., soy) may represent a promising source of biologically active compounds (e.g., genistein) as efficient alternatives to conventional treatment. Genistein as natural SERM has the unique ability to selectively act as agonist or antagonist in a tissue-specific manner, i.e., it improves skin repair and simultaneously exerts anti-cancer and chemopreventive properties. Hence, we present here a wound healing phases-based review of the most studied naturally occurring SERM.

Network pharmacology-based analysis for unraveling potential cancer-related molecular targets of Egyptian propolis phytoconstituents accompanied with molecular docking and in vitro studies

Cancer is one of the predominant causes of death worldwide. The new trend nowadays is to exploit natural products with the hope of developing new anticancer agents with fewer side effects. Propolis is one of these natural products which showed effectiveness in cancer treatment. The aim of this study is to understand the multi-level mechanism of action of propolis constituents in cancer treatment using an integrated approach of network pharmacology-based analysis, molecular docking and in vitro cytotoxicity testing. An inhouse database of chemical constituents from Egyptian propolis was compiled and assessed for its ADME properties using the QikProp module in the Schrodinger software. STITCH, UniProt, STRING, KEGG and DAVID databases were used for construction of constituent-target gene, gene-pathway, and constituent-target gene-pathway networks with the aid of Cytoscape 3.8.2. The network pharmacology-based analysis showed that the hit propolis constituents related to cancer targets were genistein, luteolin, benzoic acid, quercetin and vanillic acid, whereas the main cancer-associated targets were CYP1A1, CYP19A1, ESR1, NOS3, CASP3 and AKT1. Twenty-four cancer-related pathways were recognized where the most enriched ones were pathways in cancer and estrogen signaling pathway. The most enriched biological processes involved in the mechanism of action of propolis constituents in cancer treatment were negative regulation of the apoptotic process and the metabolic process and negative regulation of cellular glucuronidation. Molecular docking analysis of the top hit compounds against the most enriched target proteins in the constructed networks was carried out using the Maestro interface of the Schrodinger software. Among hit compounds, quercetin and genistein exhibited the most stabilized interaction. Finally, confirmation of the potential anticancer activity of propolis was assured by in vitro cytotoxicity testing of propolis extract on human prostate cancer (DU-145), breast adenocarcinoma (MCF-7) and colorectal adenocarcinoma (Caco-2) cell lines. This study presents deeper insights about propolis molecular mechanisms of action in cancer for the first time using an integrated approach of network pharmacology, molecular docking and in vitro testing.

Protective effect of genistein in a rat model of ischemic acute kidney injury

BACKGROUND

This study determined the possible anti-inflammatory and antioxidant renal protective effect of genistein, a soy isoflavone, against kidney damage and functional disorders following renal ischemia/reperfusion (I/R) in male rats.

MATERIALS AND METHODS

The animals were dedicated to five groups (n = 7 per group): Sham, Sham + Geni (genistein, 15 mg/kg in 1 ml 1% DMSO, i.p.), Sham + DMSO (1 ml 1% DMSO, i.p.), I/R (bilateral renal ischemia for 45 min followed by 24 h reperfusion), I/R + Geni (genistein, 15 mg/kg). 24-h urine samples, blood and tissue samples of the kidney were collected at the end of 24 h reperfusion period.

RESULTS

Compared to sham, sham + Geni and sham + DMSO groups, IR injury (IRI) ended in kidney dysfunction (decreased creatinine clearance, and increased fractional excretion of sodium), increased levels of malondialdehyde, decreased activities of antioxidant enzymes (superoxide dismutase, gluthatione peroxidase, and catalase), increased gene expression levels of TLR4 (Toll-like receptor 4) and TNF-α (tumor necrosis factor-alpha), as well as histological damages in kidney tissue. Genistein administration decreased all the changes. Therefore, genistein apparently protects the kidney against IRI by mitigating both oxidative stress and inflammation. The antioxidant and anti-inflammatory properties of genistein probably exert important roles in improving functional disorders and offer renal protection against IRI.

E2β stimulates ovine uterine artery endothelial cell H2S production in vitro by estrogen receptor-dependent upregulation of cystathionine β-synthase and cystathionine γ-lyase expression†

Endogenous hydrogen sulfide (H2S) is a potent vasodilator and proangiogenic second messenger synthesized from L-cysteine by cystathionine β-synthase (CBS) and cystathionine γ-lyase (CTH). Estrogens are potent vasodilators that stimulate H2S biosynthesis in uterine arteries (UA) in vivo; however, the underlying mechanisms are unknown. We hypothesized that estrogens stimulate H2S biosynthesis in UA endothelial cells (UAEC) via specific estrogen receptor (ER)-dependent mechanisms. In cultured primary UAEC, treatment with estradiol-17β (E2β) stimulated CBS and CTH mRNAs and proteins in a time- and concentration-dependent fashion. As little as 0.1 nM E2β was effective in increasing CBS and CTH expressions and these stimulatory effects maximized with 10-100 nM E2β at 48-72 h. E2β also activated CBS and CTH promoters in UAEC, leading to CBS and CTH expression. Treatment with E2β stimulated H2S production, which was blocked by specific inhibitors of either CBS or CTH and their combination and the ER antagonist ICI 182780. Treatment with either specific agonist of ERα or ERβ stimulated both CBS and CTH mRNA and protein expressions and H2S production to levels similar to that of E2β. Specific antagonist of either ERα or ERβ blocked E2β-stimulated CBS and CTH mRNA and protein expressions and H2S production. Combinations of either ERα or ERβ agonists or their antagonists had no additive effects. Thus, E2β stimulates H2S production by upregulating CBS and CTH mRNA and protein expressions through specific ERα or ERβ-dependent CBS and CTH transcription in UAEC in vitro.

Total Flavones of Rhododendron simsii Planch Flower Protect against Cerebral Ischemia-Reperfusion Injury via the Mechanism of Cystathionine-γ-Lyase-Produced H2S

Total flavones of Rhododendron simsii Planch flower (TFR) have a significant protective effect against cerebral ischemia-reperfusion injury. However, its mechanism is unclear. This study investigated the protection of TFR against cerebral ischemia-reperfusion injury via cystathionine-γ-lyase- (CSE-) produced H2S mechanism. CSE-/- mice and CSE-siRNA-transfected rat were used. Relaxation of cerebral basilar artery (CBA), H2S, and CSE mRNA were measured. TFR significantly inhibited cerebral ischemia-reperfusion-induced abnormal neurological symptom and cerebral infarct in the normal rats and the CSE+/+ mice, but not in the CSE-/- mice, and the inhibition was markedly attenuated in CSE-siRNA-transfected rat; TFR elicited a significant vasorelaxation in rat CBA, and the relaxation was markedly attenuated by removal of endothelium or CSE-siRNA transfection or coapplication of NO synthase inhibitor L-NAME and PGI2 synthase inhibitor Indo. CSE inhibitor PPG drastically inhibited TFR-evoked vasodilatation resistant to L-NAME and Indo in endothelium-intact rat CBA. TFR significantly increased CSE mRNA expression in rat CBA endothelial cells and H2S production in rat endothelium-intact CBA. The increase of H2S production resistant to L-NAME and Indo was abolished by PPG. Our data indicate that TFR has a protective effect against the cerebral ischemia-reperfusion injury via CSE-produced H2S and endothelial NO and/or PGI2 to relax the cerebral artery.

Effect of combined endurance-resistance training and soy extract supplementation on expression of eNOS gene in ovariectomized rats

Introduction

Menopause is an independent risk factor for cardiovascular disease (CVD). Physical exercise and soybean diets have been suggested to reduce the risk of CVD in postmenopausal women. The purpose of this study was to investigate the effects of combined resistance and endurance (RE) training and soy extract (SOY) supplementation, both known to improve endothelial function, on expression of the eNOS gene in the heart of ovariectomized (OVX) rats.

Material and methods

Fifty female Wistar rats were divided into five groups: 1) sham (SHAM); 2) ovariectomy (OVX); 3) ovariectomy with soy extract supplementation (OVX + SOY); 4) OVX with RE training (OVX + RE); 5) and ovariectomy plus RE training with soy extract supplementation (OVX + RE + SOY). RE training and soy extract supplementation were administered alone or in combination for 6 weeks. The effects of these treatments on cardiac eNOS expression were measured using real-time PCR.

Results

Ovariectomy down-regulated cardiac eNOS gene expression; however, 6 weeks of SOY treatment or RE training reversed this effect (p ≤ 0.05). The combination of SOY plus RE was greater than RE or SOY alone in reversing estrogen-deficiency-caused eNOS down-regulation (p ≤ 0.05).

Conclusions

Our data suggest that the combinatory regimen of soy extract supplementation and regular RE training may be more beneficial to cardiovascular disease risk in a menopause rat model than either exercise or soy supplementation alone.

Dietary Total Isoflavone Intake Is Associated With Lower Systolic Blood Pressure: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

The effect of dietary isoflavone intake on systolic blood pressure (SBP) has not been studied in a large community-based cohort inclusive of African Americans. The authors analyzed data from the year 20 examination of the Coronary Artery Risk Development in Young Adults (CARDIA) study, including medical history, physical examination, and dietary intake surveys for 3142 participants. Multivariable linear regression models controlled for age, sex, body mass index, smoking, physical activity, and intakes of alcohol and total energy. Effect modification by race was tested. Overall, patients with hypertension had a lower daily intake of total dietary isoflavones (2.2±5.2 mg/d vs 4.1±11.7 mg/d; P<.001). In fully adjusted models, the highest quartile of dietary isoflavone intake was associated with a 4.4 mm Hg lower SBP on average compared with SBP for the lowest quartile. The relationship between dietary isoflavone intake and SBP was more pronounced among African Americans compared with Caucasians (P for interaction <.001). Greater dietary intake of isoflavones was independently associated with a lower SBP.

A Mouse Model for Studying Nutritional Programming: Effects of Early Life Exposure to Soy Isoflavones on Bone and Reproductive Health

Over the past decade, our research group has characterized and used a mouse model to demonstrate that "nutritional programming" of bone development occurs when mice receive soy isoflavones (ISO) during the first days of life. Nutritional programming of bone development can be defined as the ability for diet during early life to set a trajectory for better or compromised bone health at adulthood. We have shown that CD-1 mice exposed to soy ISO during early neonatal life have higher bone mineral density (BMD) and greater trabecular inter-connectivity in long bones and lumbar spine at young adulthood. These skeletal sites also withstand greater forces before fracture. Because the chemical structure of ISO resembles that of 17-β-estradiol and can bind to estrogen receptors in reproductive tissues, it was prudent to expand analyses to include measures of reproductive health. This review highlights aspects of our studies in CD-1 mice to understand the early life programming effects of soy ISO on bone and reproductive health. Preclinical mouse models can provide useful data to help develop and guide the design of studies in human cohorts, which may, depending on findings and considerations of safety, lead to dietary interventions that optimize bone health.

Genistein ameliorated endothelial nitric oxidase synthase uncoupling by stimulating sirtuin-1 pathway in ox-LDL-injured HUVECs

Endothelial nitric oxidase synthase (eNOS) uncoupling plays a causal role in endothelial dysfunction in atherosclerosis. Genistein consumption has been associated with the prevention of atherosclerosis. However, the effect of genistein on eNOS uncoupling has not been reported. A model of oxidized low-density lipoprotein (ox-LDL)-induced injury on human umbilical vein endothelial cells (HUVECs) was established to evaluate the effect of genistein on eNOS uncoupling. We investigated the effect of genistein on NADPH oxidase-dependent superoxide production, NOX4 expression, BH4 synthesis and oxidation, the expression of GTP cyclohydrolase 1 (GCH1) and dihydrofolate reductase (DHFR). The results showed that genistein decreased superoxide production and NOX4 expression, enhanced the ratio of BH4/BH2, augmented the expressions of GCH1 and DHFR. Accompanied with genistein ameliorating eNOS uncoupling, genistein elevated the expression of sirtuin-1; furthermore, the effects of genistein on eNOS uncoupling were blunted with sirtuin-1 siRNA. The present study indicated that genistein ameliorated eNOS uncoupling was concerned with sirtuin-1 pathway in ox-LDL-injured HUVECs.

Polyphenol Stilbenes: Molecular Mechanisms of Defence against Oxidative Stress and Aging-Related Diseases

Numerous studies have highlighted the key roles of oxidative stress and inflammation in aging-related diseases such as obesity, type 2 diabetes, age-related macular degeneration (AMD), and Alzheimer's disease (AD). In aging cells, the natural antioxidant capacity decreases and the overall efficiency of reparative systems against cell damage becomes impaired. There is convincing data that stilbene compounds, a diverse group of natural defence phenolics, abundant in grapes, berries, and conifer bark waste, may confer a protective effect against aging-related diseases. This review highlights recent data helping to clarify the molecular mechanisms involved in the stilbene-mediated protection against oxidative stress. The impact of stilbenes on the nuclear factor-erythroid-2-related factor-2 (Nrf2) mediated cellular defence against oxidative stress as well as the potential roles of SQSTM1/p62 protein in Nrf2/Keap1 signaling and autophagy will be summarized. The therapeutic potential of stilbene compounds against the most common aging-related diseases is discussed.

Regulation of vascular endothelial genes by dietary flavonoids: structure-expression relationship studies and the role of the transcription factor KLF-2

Physiological concentrations (1 μM) of 15 flavonoids were evaluated in human umbilical vein endothelial cells in the presence of hydrogen peroxide (H₂O₂) for their ability to affect endothelial nitric oxide synthase (eNOS) and endothelin-1 (ET-1) expression in order to establish the structural basis of their bioactivity. Flavonoid effects on eNOS transcription factor Krüpple like factor-2 (KLF-2) expression were also evaluated. All studied flavonoids appeared to be effective compounds for counteracting the oxidative stress-induced effects on vascular gene expression, indicating that flavonoids are an excellent source of functional endothelial regulator products. Notably, the more effective flavonoids for KLF-2 up-regulation resulted in the highest values for eNOS expression, showing that the increment of eNOS expression would take place through KLF-2 induction. Structure-activity relationship studies showed that the combinations of substructures on flavonoid skeleton that regulate eNOS expression are made up of the following elements: glycosylation and hydroxylation of C-ring, double bond C2=C3 at C-ring, methoxylation and hydroxylation of B-ring, ketone group in C4 at C-ring and glycosylation in C7 of A-ring, while flavonoid features involved in the reduction of vasoconstrictor ET-1 expression are as follows: double bond C2=C3 at C-ring glycosylation in C7 of A-ring and ketone group in C4 of C-ring.

Coumestrol inhibits carotid sinus baroreceptor activity by cAMP/PKA dependent nitric oxide release in anesthetized male rats

Phytoestrogens could offer multiple beneficial effects on the cardiovascular system. Here, we have examined the effects of coumestrol (CMT) on carotid baroreceptors activity (CBA) and the possible mechanisms in male rats. The functional parameters of carotid baroreceptors were measured by recording sinus nerve afferent discharge in anesthetized male rats with perfused isolated carotid sinus. The levels of protein expression were determined by using ELISA and Western blotting. CMT (1 to 100μmolL(-1)) inhibited CBA, which shifted the functional curve of the carotid baroreceptor to the right and downward, with a marked decrease in the peak slope and the peak integral value of carotid sinus nerve discharge in a concentration dependent manner. These effects were not blocked by a specific estrogen receptor antagonist ICI 182,780, but were completely abolished by nitric oxide (NO) synthase inhibitor l-NAME (N(G)-nitro-l-arginine methyl ester). Furthermore, a NO donor, SIN-1(3-morpholion-sydnon-imine), could potentiate these inhibitory effects of CMT. CMT stimulated the phosphorylation of Ser(1176)-eNOS (endothelial nitric oxide synthase) in a dose-dependent manner in carotid bifurcation tissue over a perfusion period of 15min. The rapid activation of eNOS by CMT was blocked by a highly selective PKA (protein kinase A) inhibitor H89. In addition, inhibition of PI3K (phosphatidylinositol-3-kinase) and ERK (extracellular signal-regulated kinase) pathways had no effect on eNOS activation by CMT. CMT inhibited CBA via eNOS activation and NO synthesis. These effects were mediated by the cAMP/PKA pathway and were unrelated to the estrogenic effect.

Dietary polyphenols regulate endothelial function and prevent cardiovascular disease

Vascular endothelial cell (EC) dysfunction strongly induces development of cardiovascular and cerebrovascular diseases. Epidemiologic studies demonstrated a preventative effect of dietary polyphenols toward cardiovascular disease. In studies using cultured vascular ECs, polyphenols were recognized to regulate nitric oxide and endothelin-1 (ET-1) production. Furthermore, epigallocatechin-3-gallate inhibited the expression of adhesion molecules by a signaling pathway that is similar to that of high-density lipoprotein and involves induction of Ca(2+)/calmodulin-dependent kinase II, liver kinase B, and phosphatidylinositol 3-kinase expression. The effects of polyphenols on ECs include antioxidant activity and enhancement of the expression of several protective proteins, including endothelial nitric oxide synthase and paraoxonase 1. However, the observed effects of dietary polyphenols in vitro do not always translate to an in vivo setting. As such, there are many questions concerning their physiological mode of action. In this review, we discuss research on the effect of dietary polyphenols on cardiovascular disease and their protective effect on EC dysfunction.

Genistein inhibits TNF-α-induced endothelial inflammation through the protein kinase pathway A and improves vascular inflammation in C57BL/6 mice

Genistein, a soy isoflavone, has received wide attention for its potential to improve vascular function, but the mechanism of this effect is unclear. Here, we report that genistein at physiological concentrations (0.1 μM-5 μM) significantly inhibited TNF-α-induced adhesion of monocytes to human umbilical vein endothelial cells, a key event in the pathogenesis of atherosclerosis. Genistein also significantly suppressed TNF-α-induced production of adhesion molecules and chemokines such as sICAM-1, sVCAM-1, sE-Selectin, MCP-1 and IL-8, which play key role in the firm adhesion of monocytes to activated endothelial cells (ECs). Genistein at physiologically relevant concentrations didn't significantly induce antioxidant enzyme activities or scavenge free radicals. Further, blocking the estrogen receptors (ERs) in ECs didn't alter the preventive effect of genistein on endothelial inflammation. However, inhibition of protein kinase A (PKA) significantly attenuated the inhibitory effects of genistein on TNF-α-induced monocyte adhesion to ECs as well as the production of MCP-1 and IL-8. In animal study, dietary genistein significantly suppressed TNF-α-induced increase in circulating chemokines and adhesion molecules in C57BL/6 mice. Genistein treatment also reduced VCAM-1 and monocytes-derived F4/80-positive macrophages in the aorta of TNF-α-treated mice. In conclusion, genistein protects against TNF-α-induced vascular endothelial inflammation both in vitro and in vivo models. This anti-inflammatory effect of genistein is independent of the ER-mediated signaling machinery or antioxidant activity, but mediated via the PKA signaling pathway.

Genistein attenuates vascular endothelial impairment in ovariectomized hyperhomocysteinemic rats

Hyperhomocysteinemia (HHcy) is a well-known independent risk factor for vascular diseases in the general population. This study was to explore the effect of genistein (GST), a natural bioactive compound derived from legumes, on HHcy-induced vascular endothelial impairment in ovariectomized rats in vivo. Thirty-two adult female Wistar rats were assigned randomly into four groups (n = 8): (a) Con: control; (b) Met: 2.5% methionine diet; (c) OVX + Met: ovariectomy + 2.5% methionine diet; (d) OVX + Met + GST: ovariectomy + 2.5% methionine diet + supplementation with genistein. After 12 wk of different treatment, the rats' blood, toracic aortas and liver samples were collected for analysis. Results showed that high-methionine diet induced both elevation of plasma Hcy and endothelial dysfunction, and ovariectomy deteriorated these injuries. Significant improvement of both functional and morphological changes of vascular endothelium was observed in OVX + Met + GST group; meanwhile the plasma Hcy levels decreased remarkably. There were significant elevations of plasma ET-1 and liver MDA levels in ovariectomized HHcy rats, and supplementation with genistein could attenuate these changes. These results implied that genistein could lower the elevated Hcy levels, and prevent the development of endothelial impairment in ovariectomized HHcy rats. This finding may shed a novel light on the anti-atherogenic activities of genistein in HHcy patients.