Genistein and endothelial function in postmenopausal women with metabolic syndrome

Effect of soy isoflavone supplementation on blood pressure: a meta-analysis of randomized controlled trials

BACKGROUND

Previous experimental studies have suggested that the consumption of soy isoflavones may have a potential impact on lowering blood pressure. Nevertheless, epidemiological studies have presented conflicting outcomes concerning the correlation between soy isoflavone consumption and blood pressure levels. Consequently, a comprehensive meta-analysis of all eligible randomized controlled trials (RCTs) was conducted to explore the influence of soy isoflavones on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in adults.

METHODS

A thorough search of PubMed, Embase, and the Cochrane Library for relevant literature up to April 30, 2023 was conducted. RCTs involving adults that compared soy isoflavone supplementation with a placebo (the same matrix devoid of soy isoflavone) were included. The combined effect size was presented as the weighted mean difference (WMD) along with 95% confidence interval (CI), employing a fixed-effects model.

RESULTS

Our meta-analysis included a total of 24 studies involving 1945 participants. The results revealed a significant reduction in both SBP and DBP with soy isoflavone supplementation. Subgroup analyses suggested more pronounced reductions in SBP and DBP for interventions lasting ≥6 months, in individuals receiving mixed-type soy isoflavone, and among patients with metabolic syndrome or prehypertension. However, we did not detect significant nonlinear associations between supplementation dosage and intervention duration concerning both SBP and DBP. The overall quality of evidence was deemed moderate.

CONCLUSIONS

The current meta-analysis revealed that supplementation with soy isoflavones alone effectively reduces blood pressure. Additional high-quality studies are required to investigate the efficacy of blood pressure reduction through supplementation with an optimal quantity and proportion of soy isoflavone.

Isoflavones Effects on Vascular and Endothelial Outcomes: How Is the Gut Microbiota Involved?

Isoflavones are a group of (poly)phenols, also defined as phytoestrogens, with chemical structures comparable with estrogen, that exert weak estrogenic effects. These phytochemical compounds have been targeted for their proven antioxidant and protective effects. Recognizing the increasing prevalence of cardiovascular diseases (CVD), there is a growing interest in understanding the potential cardiovascular benefits associated with these phytochemical compounds. Gut microbiota may play a key role in mediating the effects of isoflavones on vascular and endothelial functions, as it is directly implicated in isoflavones metabolism. The findings from randomized clinical trials indicate that isoflavone supplementation may exert putative effects on vascular biomarkers among healthy individuals, but not among patients affected by cardiometabolic disorders. These results might be explained by the enzymatic transformation to which isoflavones are subjected by the gut microbiota, suggesting that a diverse composition of the microbiota may determine the diverse bioavailability of these compounds. Specifically, the conversion of isoflavones in equol-a microbiota-derived metabolite-seems to differ between individuals. Further studies are needed to clarify the intricate molecular mechanisms behind these contrasting results.

Therapeutic Potential of Phenolic Compounds in Medicinal Plants-Natural Health Products for Human Health

Phenolic compounds and flavonoids are potential substitutes for bioactive agents in pharmaceutical and medicinal sections to promote human health and prevent and cure different diseases. The most common flavonoids found in nature are anthocyanins, flavones, flavanones, flavonols, flavanonols, isoflavones, and other sub-classes. The impacts of plant flavonoids and other phenolics on human health promoting and diseases curing and preventing are antioxidant effects, antibacterial impacts, cardioprotective effects, anticancer impacts, immune system promoting, anti-inflammatory effects, and skin protective effects from UV radiation. This work aims to provide an overview of phenolic compounds and flavonoids as potential and important sources of pharmaceutical and medical application according to recently published studies, as well as some interesting directions for future research. The keyword searches for flavonoids, phenolics, isoflavones, tannins, coumarins, lignans, quinones, xanthones, curcuminoids, stilbenes, cucurmin, phenylethanoids, and secoiridoids medicinal plant were performed by using Web of Science, Scopus, Google scholar, and PubMed. Phenolic acids contain a carboxylic acid group in addition to the basic phenolic structure and are mainly divided into hydroxybenzoic and hydroxycinnamic acids. Hydroxybenzoic acids are based on a C6-C1 skeleton and are often found bound to small organic acids, glycosyl moieties, or cell structural components. Common hydroxybenzoic acids include gallic, syringic, protocatechuic, p-hydroxybenzoic, vanillic, gentistic, and salicylic acids. Hydroxycinnamic acids are based on a C6-C3 skeleton and are also often bound to other molecules such as quinic acid and glucose. The main hydroxycinnamic acids are caffeic, p-coumaric, ferulic, and sinapic acids.

Exploratory analysis of the effect of a controlled lifestyle intervention on inflammatory markers - the Healthy Lifestyle Community Programme (cohort 2)

BACKGROUND

Chronic low-grade inflammation is associated with an increased risk of chronic disease and mortality. The objective of the study was to test the effect of a healthy lifestyle intervention on biomarkers of inflammation (among other risk markers).

METHODS

We conducted a non-randomized controlled trial with mostly middle-aged and elderly participants from the general population in rural northwest Germany (intervention: n = 114; control: n = 87). The intervention consisted of a 1-year lifestyle programme focusing on diet (largely plant-based; strongest emphasis), physical activity, stress management, and social support. High-sensitivity C-reactive protein (hs-CRP) was assessed at baseline, 10 weeks, 6 months, and 1 year. Homocysteine (Hcy) was assessed at baseline, 10 weeks, and 1 year. Adiponectin (Apn) was assessed at baseline and 10 weeks. An exploratory analysis of these inflammatory markers assessing the between-group differences with ANCOVA was conducted.

RESULTS

The 1-year trajectory of hs-CRP was significantly lower in the intervention group compared to control (between-group difference: -0.8 (95% CI -1.2, -0.3) mg/l; p = 0.001; adjusted for baseline). The 1-year trajectory of Hcy was non-significantly higher in the intervention compared to control (between-group difference: 0.2 (95% CI -0.3, 0.7) µmol/l; p = 0.439; adjusted for baseline). From baseline to 10 weeks, Apn decreased significantly more in the intervention group compared to control (between-group difference: -1.6 (95% CI -2.7, -0.5) µg/ml; p = 0.004; adjusted for baseline).

CONCLUSIONS

Our study shows that healthy lifestyle changes can lower hs-CRP and Apn levels and are unlikely to significantly affect Hcy levels within 1 year.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS; reference: DRKS00018775 , registered 12 Sept 2019; retrospectively registered; www.drks.de ).

Phytoestrogens and Health Effects

Phytoestrogens are literally estrogenic substances of plant origin. Although these substances are useful for plants in many aspects, their estrogenic properties are essentially relevant to their predators. As such, phytoestrogens can be considered to be substances potentially dedicated to plant-predator interaction. Therefore, it is not surprising to note that the word phytoestrogen comes from the early discovery of estrogenic effects in grazing animals and humans. Here, several compounds whose activities have been discovered at nutritional concentrations in animals and humans are examined. The substances analyzed belong to several chemical families, i.e., the flavanones, the coumestans, the resorcylic acid lactones, the isoflavones, and the enterolignans. Following their definition and the evocation of their role in plants, their metabolic transformations and bioavailabilities are discussed. A point is then made regarding their health effects, which can either be beneficial or adverse depending on the subject studied, the sex, the age, and the physiological status. Toxicological information is given based on official data. The effects are first presented in humans. Animal models are evoked when no data are available in humans. The effects are presented with a constant reference to doses and plausible exposure.

Genistein Alleviates Oxidative Stress and Inflammation in the Hypothalamic Paraventricular Nucleus by Activating the Sirt1/Nrf2 Pathway in High Salt-Induced Hypertension

Hypertension caused by a high-salt (HS) diet is one of the major causes of cardiovascular diseases. Underlining pathology includes oxidative stress and inflammation in the hypothalamic paraventricular nucleus (PVN). This study investigates genistein's (Gen) role in HS-induced hypertension and the underlying molecular mechanism. We placed male Wistar rats on HS (8% NaCl) or normal salt diet (0.3% NaCl). Then, we injected bilateral PVN in rats with Gen, vehicle, or nicotinamide (NAM) for 4 weeks. Tail cuff was used weekly to assess the systolic pressure, diastolic pressure, and mean arterial pressure (MAP). Cardiac hypertrophy was analyzed by heart weight/body weight ratio and wheat germ agglutinin staining. ELISA kits, Western blot, or dihydroethidium staining determined the levels of inflammatory cytokines and oxidative stress markers. Western blot measured protein levels of Sirt1, Ac-FOXO1, Nrf2, NQO-1, HO-1, and gp91^phox. Our result showed that PVN infusion of Gen significantly reduced the increase of systolic pressure, diastolic pressure, and MAP induced by an HS diet. Additionally, there was a decrease in cardiac hypertrophy and the levels of inflammatory cytokines in PVN and plasma. Meanwhile, PVN infusion of Gen notably inhibited the levels of oxidized glutathione and superoxide dismutase and improved the glutathione level and total antioxidant capacities and superoxide dismutase activities. It also decreased the level of reactive oxygen species and gp91^phox expression in PVN. Furthermore, Gen infusion markedly increases the Sirt1, Nrf2, HO-1, and NQO-1 levels and decreases the Ac-FOXO1 level. However, PVN infusion of NAM could significantly block these changes induced by Gen in HS diet rats. Our results demonstrated that PVN infusion of Gen could inhibit the progression of hypertension induced by an HS diet by activating the Sirt1/Nrf2 pathway.

The Potential of Dietary Bioactive Compounds against SARS-CoV-2 and COVID-19-Induced Endothelial Dysfunction

COVID-19 is an endothelial disease. All the major comorbidities that increase the risk for severe SARS-CoV-2 infection and severe COVID-19 including old age, obesity, diabetes, hypertension, respiratory disease, compromised immune system, coronary artery disease or heart failure are associated with dysfunctional endothelium. Genetics and environmental factors (epigenetics) are major risk factors for endothelial dysfunction. Individuals with metabolic syndrome are at increased risk for severe SARS-CoV-2 infection and poor COVID-19 outcomes and higher risk of mortality. Old age is a non-modifiable risk factor. All other risk factors are modifiable. This review also identifies dietary risk factors for endothelial dysfunction. Potential dietary preventions that address endothelial dysfunction and its sequelae may have an important role in preventing SARS-CoV-2 infection severity and are key factors for future research to address. This review presents some dietary bioactives with demonstrated efficacy against dysfunctional endothelial cells. This review also covers dietary bioactives with efficacy against SARS-CoV-2 infection. Dietary bioactive compounds that prevent endothelial dysfunction and its sequelae, especially in the gastrointestinal tract, will result in more effective prevention of SARS-CoV-2 variant infection severity and are key factors for future food research to address.

Association of soy food with cardiovascular outcomes and all-cause mortality in a Chinese population: a nationwide prospective cohort study

PURPOSE

This study aimed to clarify the association of soy intake with cardiovascular disease (CVD) and all-cause mortality.

METHODS

We conducted a prospective cohort study in a Chinese population composed of 97,930 participants aged ≥ 40 years old without CVD at baseline in 2011. Habitual soy intake over a period of 12 months was evaluated using a food frequency questionnaire. All participants were classified into four groups based on their soy food consumption levels: < 15, 15-29, 30-59, and ≥ 60 g/day, with the lowest category as the reference group. Follow-up was conducted between 2014 and 2016 to assess CVD incidence and all-cause mortality since baseline, which was collected from the local mortality and disease registers of the National Disease Surveillance Point System and National Health Insurance System. The Cox proportional hazards regression models were used to analyze the relationship of soy intake with later CVD events and all-cause mortality.

RESULTS

During 350,604 person-years of follow-up (median [interquartile range]: 3.16 [2.98, 4.77] years), 2523 total CVD events and 1473 all-cause mortalities were documented. After controlling for covariates, the hazard ratios (95% confidence intervals) for total CVD events across increasing soy intake levels were 1.03 (0.93-1.14); 0.96 (0.86-1.07); and 0.86 (0.75-0.98; p for trend = 0.0434), while those for all-cause mortality were 0.88 (0.77-1.02); 0.86 (0.74-1.00); and 0.83 (0.69-0.99; p for trend = 0.0084).

CONCLUSION

High soy intake was associated with a reduced risk of total CVD events and all-cause mortality among a Chinese population.

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.

Sex Differences in Nonalcoholic Fatty Liver Disease: Estrogen Influence on the Liver-Adipose Tissue Crosstalk

Significance: Nonalcoholic fatty liver disease (NAFLD) is a hepatic and systemic disorder with a complex multifactorial pathogenesis. Owing to the rising incidence of obesity and diabetes mellitus, the prevalence of NAFLD and its impact on global health care are expected to increase in the future. Differences in NAFLD exist between males and females, and among females depending on their reproductive status. Clinical and preclinical data show that females in the fertile age are more protected against NAFLD, and studies in postmenopausal women and ovariectomized animal models support a protective role for estrogens. Recent Advances: An efficient crosstalk between the liver and adipose tissue is necessary to regulate lipid and glucose metabolism, protecting the liver from steatosis and insulin resistance contributing to NALFD. New advances in the knowledge of sexual dimorphism in liver and adipose tissue are providing interesting clues about the sex differences in NAFLD pathogenesis that could inspire new therapeutic strategies. Critical Issues: Sex hormones influence key master regulators of lipid metabolism and oxidative stress in liver and adipose tissue. All these sex-biased metabolic adjustments shape the crosstalk between liver and adipose tissue, contributing to the higher protection of females to NAFLD. Future Directions: The development of novel drugs based on the protective action of estrogens, but without its feminizing or undesired side effects, might provide new therapeutic strategies for the management of NAFLD. Antioxid. Redox Signal. 35, 753-774.

Genistein: An Integrative Overview of Its Mode of Action, Pharmacological Properties, and Health Benefits

Genistein is an isoflavone first isolated from the brooming plant Dyer's Genista tinctoria L. and is widely distributed in the Fabaceae family. As an isoflavone, mammalian genistein exerts estrogen-like functions. Several biological effects of genistein have been reported in preclinical studies, such as the antioxidant, anti-inflammatory, antibacterial, and antiviral activities, the effects of angiogenesis and estrogen, and the pharmacological activities on diabetes and lipid metabolism. The purpose of this review is to provide up-to-date evidence of preclinical pharmacological activities with mechanisms of action, bioavailability, and clinical evidence of genistein. The literature was researched using the most important keyword "genistein" from the PubMed, Science, and Google Scholar databases, and the taxonomy was validated using The Plant List. Data were also collected from specialized books and other online resources. The main positive effects of genistein refer to the protection against cardiovascular diseases and to the decrease of the incidence of some types of cancer, especially breast cancer. Although the mechanism of protection against cancer involves several aspects of genistein metabolism, the researchers attribute this effect to the similarity between the structure of soy genistein and that of estrogen. This structural similarity allows genistein to displace estrogen from cellular receptors, thus blocking their hormonal activity. The pharmacological activities resulting from the experimental studies of this review support the traditional uses of genistein, but in the future, further investigations are needed on the efficacy, safety, and use of nanotechnologies to increase bioavailability and therapeutic efficacy.

Review of Natural Resources With Vasodilation: Traditional Medicinal Plants, Natural Products, and Their Mechanism and Clinical Efficacy

For decades, chronic diseases including cardiovascular and cerebrovascular diseases (CCVDs) have plagued the world. Meanwhile, we have noticed a close association between CCVDs and vascular lesions, such as hypertension. More focus has been placed on TMPs and natural products with vasodilation and hypotension. TMPs with vasodilatory and hypotensive activities are mainly from Compositae, Lamiaceae, and Orchidaceae (such as V. amygdalina Del., T. procuinbens L., M. glomerata Spreng., K. galanga L., etc.) whereas natural products eliciting vasorelaxant potentials were primarily from flavonoids, phenolic acids and alkaloids (such as apigenin, puerarin, curcumin, sinomenine, etc.). Furthermore, the data analysis showed that the vasodilatory function of TMPs was mainly concerned with the activation of eNOS, while the natural products were primarily correlated with the blockage of calcium channel. Thus, TMPs will be used as alternative drugs and nutritional supplements, while natural products will be considered as potential therapies for CCVDs in the future. This study provides comprehensive and valuable references for the prevention and treatment of hypertension and CCVDs and sheds light on the further studies in this regard. However, since most studies are in vitro and preclinical, there is a need for more in-depth researches and clinical trials to understand the potential of these substances.

Genistein for glycolipid metabolism in postmenopausal women: a meta-analysis

OBJECTIVE

This study aimed to evaluate the effects of genistein on glycolipid metabolism in postmenopausal women.

METHODS

Electronic databases were searched and relevant reports were hand-screened. We included only randomized controlled trials of isolated genistein for glycolipid metabolism. The primary outcome for lipid metabolism included a changed value of low-density lipoprotein cholesterol (LDL-C), and for glucose metabolism was a changed value of homeostasis model assessment for insulin resistance (HOMA-IR). Secondary outcomes included a changed value of total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), fasting blood insulin (INS), and body mass index (BMI).

RESULTS

Ten trials with 11 articles were included. The level of LDL-C was not decreased in the genistein group compared with the placebo group (standardized mean difference [SMD] = -0.58; 95% confidence interval [CI] - 1.19, 0.02; p = 0.06). No statistical significance was found in subgroup analyses. HOMA-IR was obviously improved in the genistein group with SMD of -0.51 (95% CI -0.88, -0.14; p = 0.006). In subgroup analyses, HOMA-IR was improved more in women with BMI <30 kg/m² and without metabolic disorders (p < 0.0001). For secondary outcomes, there were significant differences in total cholesterol, HDL-C, FBG, and INS, but not triglyceride or BMI.

CONCLUSIONS

Genistein was effective in ameliorating glycolipid metabolism by increasing HDL-C levels and decreasing total cholesterol levels and improving insulin sensitivity.

Effects of Dietary Phytoestrogens on Hormones throughout a Human Lifespan: A Review

Dietary phytoestrogens are bioactive compounds with estrogenic activity. With the growing popularity of plant-based diets, the intake of phytoestrogen-rich legumes (especially soy) and legume-derived foods has increased. Evidence from preclinical studies suggests these compounds may have an effect on hormones and health, although the results of human trials are unclear. The effects of dietary phytoestrogens depend on the exposure (phytoestrogen type, matrix, concentration, and bioavailability), ethnicity, hormone levels (related to age, sex, and physiological condition), and health status of the consumer. In this review, we have summarized the results of human studies on dietary phytoestrogens with the aim of assessing the possible hormone-dependent outcomes and health effects of their consumption throughout a lifespan, focusing on pregnancy, childhood, adulthood, and the premenopausal and postmenopausal stages. In pregnant women, an improvement of insulin metabolism has been reported in only one study. Sex hormone alterations have been found in the late stages of childhood, and goitrogenic effects in children with hypothyroidism. In premenopausal and postmenopausal women, the reported impacts on hormones are inconsistent, although beneficial goitrogenic effects and improved glycemic control and cardiovascular risk markers have been described in postmenopausal individuals. In adult men, different authors report goitrogenic effects and a reduction of insulin in non-alcoholic fatty liver patients. Further carefully designed studies are warranted to better elucidate the impact of phytoestrogen consumption on the endocrine system at different life stages.

Effects of Drugs, Phytoestrogens, Nutrients and Probiotics on Endothelial Dysfunction in the Estrogen-Deficient State

BACKGROUND

Endothelial dysfunction is commonly present in estrogen-deficient states, e.g., after menopause. In the search for alternatives to hormone replacement therapy (HRT), treatments based on phytoestrogens or in non-hormonal mechanisms have been under evaluation.

OBJECTIVE

Here we aim to present an overview of innovative potential treatments for endothelial dysfunction in estrogen-deficient states, introducing our own preliminary data about the probiotic kefir.

METHODS

We conducted a review based on a PubMed database search for keywords of interest (Menopause, Ovariectomy, Vascular dysfunction, Hot flashes, Metformin, Statins, Phytoestrogens, Omega-3, Vitamin D, Probiotics).

RESULTS

Vascular parameters were found to be improved by both metformin and statins through pleiotropic effects, being related to a decrease in oxidative stress and restoration of the nitric oxide pathway. Phytoestrogens such as genistein and resveratrol have also been shown to improve vascular dysfunction, which seems to involve their estrogenic-like actions. Omega-3, vitamin D and its analogues, as well as probiotics, have shown similar vascular beneficial effects in both postmenopausal women and an animal model of ovariectomy (OVX), which could be related to antioxidant and/or anti-inflammatory effects. Moreover, our preliminary data on the probiotic kefir treatment in OVX rats suggested a vascular antioxidant effect. In particular, some evidence points to statins and vitamin D having anti-atherogenic effects.

CONCLUSION

Pleiotropic effects of common medications and natural compounds could have therapeutic potential for endothelial dysfunction in estrogen-deficient states. They could, therefore, work as future complementary or alternative treatments to HRT.

Isoflavone Intake and the Risk of Coronary Heart Disease in US Men and Women: Results From 3 Prospective Cohort Studies

BACKGROUND

Whether soy products confer health benefits related to coronary heart disease (CHD) remains controversial because of inconsistent evidence.

METHODS

A total of 74 241 women from the NHS (Nurses' Health Study; 1984-2012), 94 233 women from the NHSII (Nurses' Health Study II; 1991-2013), and 42 226 men from the Health Professionals Follow-Up Study (1986-2012), who were free of cardiovascular disease and cancer at baseline, were included in the present analysis. Dietary data were updated every 2 to 4 years using a validated food frequency questionnaire. Nonfatal myocardial infarction and CHD deaths were adjudicated through reviewing medical records, death certificates, and other medical documents.

RESULTS

In these cohorts, 8359 incident CHD cases were documented during 4 826 122 person-years of follow-up. In multivariable-adjusted analyses, isoflavone intake was inversely associated with CHD (pooled hazard ratio [HR] comparing the extreme quintiles: 0.87 [95% CI, 0.81-0.94]; P=0.008). Consumption of tofu, but not soy milk, was inversely associated with the risk of CHD, with pooled HRs (95% CIs) of 0.82 (0.70-0.95; P=0.005) and 0.87 (0.69-1.10; P=0.41), respectively, comparing ≥1 serving/week with <1 serving/month. Further analyses showed that, in women, the favorable association of tofu was primarily driven by stronger inverse association of tofu intake observed in younger women before menopause and postmenopausal women without hormone use (P_interaction=0.002).

CONCLUSIONS

Higher intake of isoflavones and tofu was associated with a moderately lower risk of developing CHD, and in women the favorable association of tofu were more pronounced in young women or postmenopausal women without hormone use.

The effects of isolated soy protein, isolated soy isoflavones and soy protein containing isoflavones on serum lipids in postmenopausal women: A systematic review and meta-analysis

Background: Many randomized controlled trials (RCTs) have assessed the effects of soy products on serum lipids. However, the responsible soy components and the magnitude of effects in healthy or hypercholesterolemic postmenopausal women are unclear. This review assessed the quality of these RCTs and estimated the effects of isolated soy protein, isolated soy isoflavones and soy protein containing isoflavones on total cholesterol (TC), LDL-C, HDL-C, triglycerides (TG), Apolipoprotein (Apo) A-1 and Apo B among postmenopausal women.Design: Forty-six eligible randomized controlled trials published up to 20 May 2019 were identified from the PubMed, Web of Science and Scopus databases. Weighted mean effect sizes were calculated for net changes in serum lipid concentrations by using random-effect models. Specific subgroup analyses were performed to identify the effect of covariates on serum lipid changes.Results: Soy consumption was associated with significant decrease in TG (mean differences (MD): -5.04 mg/dl; 95% CI: -9.95, -0.13; P = 0.044), TC (MD: -3.02 mg/dl; 95% CI: -5.56, -0.47; P = 0.02), LDL-C (MD: -3.27 mg/dl; 95% CI: -6.01, -0.53; P = 0.019) and HDL-C (MD: -2.28 mg/dl; 95% CI: -4.27, -0.29; P = 0.025). The reduction in LDL-C, TG and HDL were larger in subjects consuming isolated soy protein than isolated soy isoflavones. There was a significant decrease in serum TG and HDL levels with dosages of >25 grams per day soy protein rather than lower dosages of soy protein. The reductions in Apo A-1 were significantly larger in hypercholesterolemic subjects than in healthy subjects.Conclusions: Isolated soy protein significantly reduced serum TG, TC, LDL-C, HDL-C and Apo-B levels in postmenopausal women. Isolated soy isoflavones had a significant lowering effect on serum TC and Apo B levels. Soy protein containing isoflavones significantly reduced TG, TC, LDL-C and Apo B levels. Therefore, hyperlipidemia risk reduction with soy products is not uniform and strongly depends on the protein and isoflavone content of soy products, duration and dosage of consumption.

Effects of genistein on blood pressure: A systematic review and meta-analysis

Genistein (4',5,7-trihydroxyisoflavone) is a phytoestrogen with potential health benefits in the prevention of cardiovascular disease. However, the evidence regarding its effects on hypertension has not been conclusive. Therefore, we examined the impact of oral genistein supplementation on systolic blood pressure (SBP) and diastolic blood pressure (DBP) via a systematic review and meta-analysis of randomized controlled trials (RCTs). PubMed, ISI Web of Science, Scopus and the Cochrane library databases (until August 2019) were searched to identify potential RCTs with information on genistein supplementation and hypertension. Weighted Mean Difference (WMD) was pooled using a random-effects model. Pooling four RCTs (four treatment arms) together did not show any significant reduction of SBP (WMD: -5.32 mmHg, 95% CI: -14.59 to 3.96) and DBP (WMD: -2.06 mmHg, 95% CI: -6.41 to 2.28) compared to that of the placebo group. However, subgroup analysis by intervention duration suggested that more than 6 months genistein supplementation in metabolic syndrome patients can significantly decrease SBP (WMD: -13.73 mmHg, 95% CI: -18.10 to -9.37) and DBP (WMD: -5.18 mmHg, 95% CI: -6.62 to -3.74). Generally, present study indicated that genistein supplementation had no effect on hypertension, but it seems that longer intervention duration of more than 6 months especially among metabolic syndrome patients may lead to the effectiveness of genistein.

Genistein as Potential Therapeutic Candidate for Menopausal Symptoms and Other Related Diseases

Plant-derived compounds have recently attracted greater interest in the field of new therapeutic agent development. These compounds have been widely screened for their pharmacological effects. Polyphenols, such as soy-derived isoflavones, also called phytoestrogens, have been extensively studied due to their ability to inhibit carcinogenesis. These compounds are chemically similar to 17β-estradiol, and mimic the binding of estrogens to its receptors, exerting estrogenic effects in target organs. Genistein is an isoflavone derived from soy-rich products and accounts for about 60% of total isoflavones found in soybeans. Genistein has been reported to exhibit several biological effects, such as anti-tumor activity (inhibition of cell proliferation, regulation of the cell cycle, induction of apoptosis), improvement of glucose metabolism, impairment of angiogenesis in both hormone-related and hormone-unrelated cancer cells, reduction of peri-menopausal and postmenopausal hot flashes, and modulation of antioxidant effects. Additionally, epidemiological and clinical studies have reported health benefits of genistein in many chronic diseases, such as cardiovascular disease, diabetes, and osteoporosis, and aid in the amelioration of typical menopausal symptoms, such as anxiety and depression. Although the biological effects are promising, certain limitations, such as low bioavailability, biological estrogenic activity, and effects on target organs, have limited the clinical applications of genistein to some extent. Moreover, studies report that modification of its molecular structure may eliminate the biological estrogenic activity and its effects on target organs. In this review, we summarize the potential benefits of genistein on menopause symptoms and menopause-related diseases like cardiovascular, osteoporosis, obesity, diabetes, anxiety, depression, and breast cancer.

Protective effect of genistein on nonalcoholic fatty liver disease (NAFLD)

NAFLD is a vital health problem worldwide; however, no effective treatment is currently available for NAFLD. Intensive studies have indicated the efficacy of genistein (GE), a bioactive isoflavone extracted from soy, in treating NAFLD. In addition to its oestrogen-like effects, GE is known to have multiple molecular effects, for instance, lipid and glucose metabolism-promoting effects and activities against lipid peroxidation, inflammation, fibrosis, and NAFLD-related tumours. Here, this review summarizes the potential role of GE in the treatment and prevention of NAFLD and some of the currently known targets and signalling pathways of GE in NAFLD.

Non-Hormonal Replacement Therapy Regimens: Do they have an Effect on Cardiovascular Risk?

INTRODUCTION

Menopause is associated with adverse effects on quality of life of perimenopausal and post-menopausal women. It also has an impact on the development of cardiovascular disease (CVD). Hormonal treatments are the most effective medications for menopausal symptoms relief. Given the fact that hormonal treatments are contraindicated for many women, non-hormonal treatment, such as Selective Serotonin Reuptake Inhibitors (SSRIs), Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs), gabapentin, pregabalin, clonidine and phytoestrogens, constitute alternative treatments. Nevertheless, little is known about their effects on CVD risk.

METHODS

PubMed, EMBASE and Cochrane Library were searched for the effects of non-hormonal treatment on CVD risk, blood pressure, heart rate, lipids and glucose concentrations, weight gain, cardiovascular events, stroke, mortality and morbidity.

RESULTS

Phytoestrogens, pregabalin and gabapentin seem to have no adverse effects on the cardiovascular system. Phytoestrogens, in particular, seem to reduce CVD risk through many pathways. On the other hand, SSRIs and SNRIs, although effective in reducing menopausal vasomotor symptoms, should be cautiously administered to women with known CVD (e.g. with cardiac arrhythmias, atherosclerotic disease or stroke). As clonidine has been associated with cardiovascular adverse effects, it should be administered only in cases where blood pressure regulation is mandatory.

CONCLUSION

Further research is needed to produce definite conclusions regarding the cardiovascular safety of non-hormonal medications for menopausal symptoms relief.

Flavonoids and Other Phenolic Compounds from Medicinal Plants for Pharmaceutical and Medical Aspects: An Overview

Phenolic compounds as well as flavonoids are well-known as antioxidant and many other important bioactive agents that have long been interested due to their benefits for human health, curing and preventing many diseases. This review attempts to demonstrate an overview of flavonoids and other phenolic compounds as the interesting alternative sources for pharmaceutical and medicinal applications. The examples of these phytochemicals from several medicinal plants are also illustrated, and their potential applications in pharmaceutical and medical aspects, especially for health promoting e.g., antioxidant effects, antibacterial effect, anti-cancer effect, cardioprotective effects, immune system promoting and anti-inflammatory effects, skin protective effect from UV radiation and so forth are highlighted.

Genistein Supplementation and Cardiac Function in Postmenopausal Women with Metabolic Syndrome: Results from a Pilot Strain-Echo Study

Genistein, a soy-derived isoflavone, may improve cardiovascular risk profile in postmenopausal women with metabolic syndrome (MetS), but few literature data on its cardiac effects in humans are available. The aim of this sub-study of a randomized double-blind case-control study was to analyze the effect on cardiac function of one-year genistein dietary supplementation in 22 post-menopausal patients with MetS. Participants received 54 mg/day of genistein (n = 11) or placebo (n = 11) in combination with a Mediterranean-style diet and regular exercise. Left ventricular (LV) systolic function was assessed as the primary endpoint, according to conventional and strain-echocardiography measurements. Also, left atrial (LA) morphofunctional indices were investigated at baseline and at the final visit. Results were expressed as median with interquartile range (IQ). A significant improvement of LV ejection fraction (20.3 (IQ 12.5) vs. −1.67 (IQ 24.8); p = 0.040)), and LA area fractional change (11.1 (IQ 22.6) vs. 2.8 (9.5); p = 0.034)) were observed in genistein patients compared to the controls, following 12 months of treatment. In addition, body surface area indexed LA systolic volume and peak LA longitudinal strain significantly changed from basal to the end of the study in genistein-treated patients. One-year supplementation with 54 mg/day of pure genistein improved both LV ejection fraction and LA remodeling and function in postmenopausal women with MetS.

Genistein supplementation improves insulin resistance and inflammatory state in non-alcoholic fatty liver patients: A randomized, controlled trial

BACKGROUND & AIMS

The beneficial effect of genistein has indicated on metabolic disorders and inflammatory state. The aim of this study was to investigate the effect of genistein supplementation on non-alcoholic fatty liver disease (NAFLD) as the hepatic manifest of metabolic syndrome.

METHODS

In the present randomized double-blind controlled trial, patients with NAFLD were daily supplemented with either 250 mg genistein (n = 41) or placebo (n = 41) for 8-weeks. Both groups were instructed to follow an energy-balanced diet and physical activity recommendations. And their anthropometric and biochemical indices were assessed before and after the intervention.

RESULTS

At the end of the study, the genistein group had lower level of serum insulin (p = 0.001) and homeostasis model assessment for insulin resistance (HOMA-IR) (p = 0.041) compare to the placebo group. In addition serum malondialdehyde (MDA) (p = 0.004), tumor necrosis factor-α (TNF-α) (p = 0.045) and interleukin (IL)-6 (p = 0.018) also were lower in the genistein group. Compare with placebo, genistein supplementation significantly reduced waist to hip ratio (p = 0.021), body fat percentage (p = 0.015) and triglyceride (p = 0.018). However, there were no significant changes in BMI, fasting blood glucose (p = 0.122), alanine aminotransferase (ALT) (p = 0.536), aspartate aminotransferase (AST) (p = 0.265) between the two groups.

CONCLUSIONS

Oral supplementation with 250 mg genistein for 8-weeks can reduce insulin resistance, oxidative and inflammatory indices along with improvement in fat metabolism in patients with NAFLD. Studies with longer duration and larger samples might be needed to reveal other beneficial effects of genistein.

Visfatin correlates with hot flashes in postmenopausal women with metabolic syndrome: effects of genistein

During menopause, an increased prevalence of metabolic syndrome (MetS) and central obesity seems to increase hot flashes (HFs). Visfatin is an inflammatory adipokine secreted by visceral fat. We investigated visfatin levels and its relationship with hot flash number and BMI, in postmenopausal women with MetS. We also evaluated the effect of genistein, an isoflavone effective in reducing HFs, on visfatin levels and HFs after 1 year of treatment. This was a randomized, double-blind, placebo-controlled trial. Postmenopausal women with MetS were randomly assigned to receive placebo (n = 60) or 54 mg genistein (n = 60), daily for 1 year. As main outcome measures, hot flashes number and circulating visfatin levels were evaluated. Visfatin significantly correlated with BMI and HFs number in women with MetS at basal. After 6 and 12 months, our results indicate a strong correlation and a significant effect of genistein in reducing both HFs and visfatin in women with MetS. The present study suggests that visfatin plays a role in the vasomotor symptoms, at least in postmenopausal women with metabolic syndrome. Genistein may reduce HFs decreasing the circulating levels of this inflammatory adipokine.

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.

Polyphenol-based nutraceuticals for the prevention and treatment of cardiovascular disease: Review of human evidence

BACKGROUND

In addition to prescription drugs, nutraceuticals/functional foods/medical foods are being increasingly added as adjunct treatment of cardiovascular disease (CVD), even though most of them have been exclusively studied in vitro.

HYPOTHESIS/PURPOSE

We review the available evidence (focusing on when the amount of polyphenols' intake was measured) coming from randomized controlled trials (RCTs) of (poly)phenol-based supplements.

CONCLUSION

We conclude that (poly)phenol-based nutraceuticals and functional foods might be indeed used as adjunct therapy of CVD, but additional long-term RCTs with adequate numerosity and with clinically relevant end points are needed to provide unequivocal evidence of their clinical usefulness.

Soy isoflavones and glucose metabolism in menopausal women: A systematic review and meta-analysis of randomized controlled trials

SCOPE

The aim of this meta-analysis was to investigate whether soy isoflavones, a type of phytoestrogen, would affect glucose homeostasis in menopausal women.

METHODS AND RESULTS

Studies concerning about the relationship between soy isoflavone treatment and glucose metabolism were searched on MEDLINE and WEB OF SCIENCE (updated through April 2015) and EMBASE (1990-April 2015). Seventeen randomized controlled trials (RCTs) with a total number of 1529 menopausal women were identified for meta-analysis. Soy isoflavones were found to show great significance for the improvement of glucose metabolism, though marked heterogeneity was found between studies. The overall results showed that the average difference in fasting blood glucose values between women assigned to soy isoflavones and women in placebo groups was -0.22 mmol/L (95% CI: -0.38 to -0.07 mmol/L) under a random-effects model. In addition, the effect of soy isoflavones on insulin was also significant: -0.43 μIU/mL (95% CI: -0.71 to -0.14 μIU/mL), as was the effect on homeostasis model assessment insulin resistance (HOMA-IR): -0.52 (95% CI: -0.76 to -0.28).

CONCLUSION

Although the results displayed a significant tendency in favor of soy isoflavones, it appears that genistein alone played an important role in improving glucose metabolism due to its low heterogeneity.

Does genistein lower plasma lipids and homocysteine levels in postmenopausal women? A meta-analysis

OBJECTIVE

To perform a meta-analysis examining the effects of genistein on homocysteine and lipid levels in postmenopausal women.

METHODS

We systematically searched the PubMed, MEDLINE, and Cochrane Library databases and the ClinicalTrials.gov website for studies. We performed a meta-analysis using weighted mean differences (WMD) and 95% confidence intervals in a random-effects model. We assessed between-study heterogeneity using the Cochran's Q and I(2) statistics.

RESULTS

Eight randomized, controlled trials with a total of 476 subjects were included in the meta-analysis. Compared with placebos, genistein was effective in reducing plasma levels of homocysteine (WMD, -0.58 μmol/l; p = 0.001), and increasing high density lipoprotein (HDL) cholesterol levels (WMD, 4.9 mg/dl; p = 0.0002). Subgroup analyses revealed that genistein significantly decreased the levels of low density lipoprotein (LDL) cholesterol (WMD, -16.90 mg/dl; p = 0.01), total cholesterol (WMD, -15.83 mg/dl; p = 0.008), and triglycerides (WMD, -46.58 mg/dl; p = 0.03) in postmenopausal women with metabolic syndrome, but had no significant effects in those with no metabolic syndrome.

CONCLUSIONS

Our meta-analysis demonstrates that genistein significantly reduces homocysteine levels and increases HDL cholesterol levels in postmenopausal women. Genistein also significantly decreases LDL cholesterol, total cholesterol and triglyceride levels in postmenopausal women with metabolic syndrome.

The effect of soy or isoflavones on homocysteine levels: a meta-analysis of randomised controlled trials

BACKGROUND

The present study aimed to evaluate the effect of soy or isoflavones on blood homocysteine levels via a systematic review and meta-analysis.

METHODS

Pubmed, Embase, Web of Science and the Cochrane Library (up to 16 December 2015) were used for the literature review. Only randomised controlled trials were included. The primary outcome was the standard mean difference (SMD) of blood homocysteine levels between the experimental and control groups.

RESULTS

Nineteen randomised controlled studies were included for qualitative analysis. Eighteen studies were included in the data synthesis. Soy or isoflavones were found to have no effect on homocysteine levels, with a SMD of -0.21 (95% confidence interval = -0.43 to 0.00, I² =67.7%, random effect model). No publication bias was found among those studies (P = 0.296 for Egger's test, and P = 0.198 for Begg's test).

CONCLUSIONS

Soy or isoflavones were not found to be associated with a reduction in homocysteine levels. Further studies might still be needed in carefully selected populations.

Genistein upregulates LDLR levels via JNK-mediated activation of SREBP-2

Background

Genistein has been proved in vitro and in vivo to lower LDLR level. It is also widely consumed and implicated for its anti-atherogenic effects. However, the molecular mechanism by which genistein lowers the LDL level is still unknown.

Objective

To understand the anti-atherogenic molecular mechanism of action, genistein was investigated for its impact on the expression of LDLR, the receptor for LDL cholesterol, and related signaling pathways in a human hepatoma cell line.

Design

HepG2 cell was used for the experiments. Genistein with different concentrations was diluted in media and was incubated for 24 h or more as indicated. Protein levels were measured by western blotting, and mRNA expression was detected by RT-qPCR. Chromatin immunoprecipitation assay (CHIP) assay was used to determine protein binding levels, and luciferase assay was used to measure promoter activity.

Result

Genistein increased the mRNA and protein levels of LDLR in a time-dependent manner. Genistein increased the transcriptional activity of the LDLR promoter containing the reporter gene (pLDLR-luc, −805 to +50). But the sterol regulatory element deletion mutant construct failed to be activated by genistein. Genistein increased the nuclear fraction of SREBP-2 and the DNA-binding activity of SREBP-2 to LDLR promoter, as assessed by CHIP. The genistein-phosphorylated JNK inhibitor (SP600126) abolished the genistein-stimulated levels of LDLR and the nuclear SREBP-2. The addition of cholesterol up to 5 µg/mL for 24 h did not affect the effect of genistein on LDLR protein expression. Even the addition of 40 µM genistein increased the cholesterol uptake by more than 10% in the human hepatoma cell line.

Conclusion

Our data support the idea that genistein may have anti-atherogenic effects by activating JNK signals and SREBP-2 processing, which is followed by the upregulation of LDLR.

Peripheral Microvascular Vasodilatory Response to Estradiol and Genistein in Women with Insulin Resistance

OBJECTIVE

E2 enhances vasodilation in healthy women, but vascular effects of the phytoestrogen GEN are still under investigation. IR compromises microvascular function. We therefore examined the interaction of E2 , GEN, and IR on microvascular vasodilatory responsiveness.

METHODS

We hypothesized that E2 and GEN increase microvascular vasodilation in healthy women (control, n = 8, 23 ± 2 year, BMI: 25.9 ± 2.9 kg/m2) but not in women with IR (n = 7, 20 ± 1 year, BMI: 27.3 ± 3.0 kg/m2). We used the cutaneous circulation as a model of microvascular vasodilatory function. We determined CVC with laser Doppler flowmetry and beat-to-beat blood pressure during local cutaneous heating (42 °C) with E2 or GEN microdialysis perfusions. Because heat-induced vasodilation is primarily an NO-mediated response, we examined microvascular vasodilation with and without L-NMMA.

RESULTS

In C, E2 enhanced CVC (94.4 ± 2.6% vs. saline 81.6 ± 4.2% CVCmax , p < 0.05), which was reversed with L-NMMA (80.9 ± 7.8% CVCmax , p < 0.05), but GEN did not affect vasodilation. Neither E2 nor GEN altered CVC in IR, although L-NMMA attenuated CVC during GEN.

CONCLUSIONS

Our study does not support improved microvascular responsiveness during GEN exposure in healthy young women, and demonstrates that neither E2 nor GEN improves microvascular vasodilatory responsiveness in women with IR.

Genistein supplementation prevents weight gain but promotes oxidative stress and inflammation in the vasculature of female obese ob/ob mice

Obesity, a state of chronic low-grade inflammation, is strongly associated with the development of hypertension and diabetes. Superoxide, a free radical elevated in obese individuals, promotes hypertension through scavenging the endogenous vasodilator nitric oxide. The hypothesis was a genistein-enriched diet would promote weight loss and reduce oxidative stress and inflammation in the vasculature of intact female ob/ob mice. Aortas and mesenteric arteries were isolated from female ob/ob mice fed genistein-free (0mg genistein/kg diet; n=6), standard chow (200-300mg genistein/kg diet; n=11) or genistein-enriched (600mg genistein/kg diet; n=9) diets for 4weeks. Sections of isolated vessels were labeled with the superoxide indicator dihydroethidium and fluorescence was measured by confocal microscopy. Protein expression of the inflammatory marker inducible nitric oxide synthase (iNOS) was measured in the perivascular adipose tissue (PVAT) surrounding each vessel and plasma concentrations of superoxide dismutase (SOD) were quantified. Genistein-enriched diet promoted less weight gain compared to animals fed standard chow (P=.008). Standard chow promoted increased superoxide in the aorta (P=.030) and mesenteric arteries (P=.024) compared to a diet devoid of genistein. At all tested concentrations, genistein significantly increased iNOS expression in mesenteric artery PVAT (vs. standard chow, P<.001; vs. genistein-enriched, P=.002) and tended to increase iNOS within the aortic PVAT (standard chow, P=.075) compared to the genistein-free group. Plasma SOD activity was significantly downregulated in genistein-enriched animals as compared to those fed a genistein-free diet (P=.028). In summary, although genistein prevents weight gain, it promotes vascular oxidative stress and inflammation in obese ovarian-intact female mice.

Oxidant/antioxidant status, paraoxonase activity, and lipid profile in plasma of ovariectomized rats under the influence of estrogen, estrogen combined with progesterone, and genistein

INTRODUCTION

The aim of this study was to investigate whether estradiol (E2), E2 combined with progesterone (Prog) (E2/Prog), and genistein (Gen) treatment had antioxidative and anti-hyperlipidemic effects in the plasma of ovariectomized (OVX) rats.

MATERIALS AND METHODS

Adult female Sprague-Dawley rats were divided into five groups. Rats in all groups, except for those in a sham group, underwent bilateral ovariectomy under general anesthesia. The groups were as follows: sham group; control OVX group; group treated with estrogen (0.014 mg/kg 17-β E2); group treated with a combination of E2 and Prog (0.014 mg/kg 17-β E2 plus 0.028 mg/kg drospirenone), and group treated with Gen (10 mg/kg/day). Plasma of rats of each treatment group was analyzed to determine the total antioxidant status, total oxidant status, paraoxonase activity, lipid profile, high-density lipoprotein (HDL-chol), low-density lipoprotein (LDL-chol), total cholesterol (Total-C), triacylglycerols, lipoprotein (a), and oxidative stress index.

RESULTS

Plasma Total-C levels and body weight increased in all the OVX groups compared with the sham group (P<0.005). The group treated with E2 had significantly elevated total oxidant status, oxidative stress index, LDL-chol, and Total-C compared with the control group (P<0.005). Gen treatment might lead to lower LDL-chol and Total-C levels compared with E2 treatment.

CONCLUSIONS

Gen treatment might be preferred to E2 treatment for treatment of menopausal symptoms in patients at risk for cardiovascular diseases. However, considering the small sample size of this study, larger studies are needed in this area.

Metabolic syndrome individuals with and without type 2 diabetes mellitus present generalized vascular dysfunction: cross-sectional study

OBJECTIVES

The first objective of this study was to demonstrate differences within endothelial-dependent and endothelial-independent vasoreactivity in macro- and microcirculation beds among patients with metabolic syndrome (MetS) with and without type 2 diabetes mellitus (T2D) compared with healthy counterparts. The second objective was to determine relationships among the function of macro- and microvascular systems and abdominal adiposity, as well as inflammatory markers in the 3 groups.

APPROACH AND RESULTS

Cross-sectional analyses of 53 patients with MetS without T2D and 25 with T2D, as well as aged 40 years and sex-matched healthy controls included microvascular (cutaneous blood flow measured with laser Doppler flowmetry in response to iontophoresis of acetylcholine and sodium nitroprusside), and macrovascular reactivity (flow-mediated dilation and nitrate-mediated dilation) along with anthropometric measures, plasma glucose, and insulin and inflammatory markers. Compared with controls, MetS participants showed depressed endothelial function of both micro- and macrocirculation beds. T2D in patients with MetS revealed an exacerbated vascular smooth muscle dysfunction in micro- and macrocirculation compared with MetS without T2D. Indices of micro- and macrocirculation were predominantly inversely related to abdominal fat and inflammatory markers.

CONCLUSIONS

MetS was associated with endothelial-dependent and endothelial-independent dysfunction, affecting both the macro- and the microvascular systems. Participants with diabetes mellitus demonstrated the most severe smooth muscle dysfunction. The presence of central abdominal fat and systemic inflammation seems implicated in the pathogenesis of vascular dysfunctions in MetS.

Bioavailability, bioactivity and impact on health of dietary flavonoids and related compounds: an update

There is substantial interest in the role of plant secondary metabolites as protective dietary agents. In particular, the involvement of flavonoids and related compounds has become a major topic in human nutrition research. Evidence from epidemiological and human intervention studies is emerging regarding the protective effects of various (poly)phenol-rich foods against several chronic diseases, including neurodegeneration, cancer and cardiovascular diseases. In recent years, the use of HPLC-MS for the analysis of flavonoids and related compounds in foods and biological samples has significantly enhanced our understanding of (poly)phenol bioavailability. These advancements have also led to improvements in the available food composition and metabolomic databases, and consequently in the development of biomarkers of (poly)phenol intake to use in epidemiological studies. Efforts to create adequate standardised materials and well-matched controls to use in randomised controlled trials have also improved the quality of the available data. In vitro investigations using physiologically achievable concentrations of (poly)phenol metabolites and catabolites with appropriate model test systems have provided new and interesting insights on potential mechanisms of actions. This article will summarise recent findings on the bioavailability and biological activity of (poly)phenols, focusing on the epidemiological and clinical evidence of beneficial effects of flavonoids and related compounds on urinary tract infections, cognitive function and age-related cognitive decline, cancer and cardiovascular disease.