Bioavailability of isoflavones after ingestion of soy beverages in healthy adults

Perspective: Isoflavones-Intriguing Molecules but Much Remains to Be Learned about These Soybean Constituents

Isoflavones are naturally occurring compounds found in a wide range of plants, but among commonly consumed foods are especially abundant in soybeans and foods derived from this legume. Much of the substantial amount of research conducted on soy protein and soy foods over the past 30 y is because of their isoflavone content. Research interest in isoflavones increased dramatically beginning in the early 1990s as evidence highlighted their possible role in the prevention of a wide range of cancers, including breast, prostate, and colon cancer. Recognition that isoflavones preferentially bind to estrogen receptor (ER)β in comparison with ERα provided a conceptual basis for classifying these diphenolic molecules as selective ER modulators (SERMs). Isoflavone research soon greatly expanded beyond cancer to include areas such as coronary artery disease, bone health, cognitive function, and vasomotor symptoms of menopause. Nevertheless, safety concerns about isoflavones, based primarily on the results of rodent studies and presumed estrogenic effects, also arose. However, recent work challenges the traditional view of the estrogenicity of isoflavones. Furthermore, safety concerns have largely been refuted by intervention and population studies. On the other hand, investigation of the proposed benefits of isoflavones has produced inconsistent data. The small sample size and short duration common to many intervention trials, combined with marked interindividual differences in isoflavone metabolism, likely contribute to the conflicting findings. Also, many different intervention products have been employed, which vary not only in the total amount, but also in the relative proportion of the 3 soybean isoflavones, and the form in which they are delivered (glycoside compared with aglycone). For those interested in exploring the proposed benefits of isoflavones, studies justify an intake recommendation of ∼50 mg/d, an amount provided by ∼2 servings of traditional Asian soy foods.

Microencapsulation techniques and encapsulating materials influenced the shelf life and digestion release of vitamin E and isoflavones in soymilk powder

Soymilk, due to its high-quality protein and isoflavones content, is widely consumed worldwide. Unfortunately, soymilk lacks the powerful antioxidant vitamin E. Encapsulation of vitamin E and isoflavones in soymilk powder is advantageous for malnourished consumers to meet the recommendation. This study aimed to evaluate the impact of different encapsulation techniques and encapsulating materials on the storage stability and bioaccessibility of vitamin E and isoflavones in soymilk powder. Freeze-drying and spray-drying methods were applied with various encapsulating materials prepared from different ratios of maltodextrin to Acacia gum (100:0, 60:40, 50:50, 40:60, and 0:100). The results indicated that a 40:60 ratio of maltodextrin and Acacia gum provided the highest stability for 24 h of soymilk emulsion under the studied conditions. The shelf-life prediction of soymilk powder increased by more than two weeks when stored at 0 °C compared to the storage at ambient temperature. Spray-drying and freeze-drying techniques effectively encapsulate vitamin E and isoflavones within core microcapsules. Especially, freeze-drying process helps to prevent degradation during storage and allows for controlled release of the bioactive compounds during in-vitro digestion. Encapsulation efficiency of isoflavones and vitamin E for all formulation ranged from 80.9 ± 0.01% to 83.5 ± 0.20%, respectively. The highest vitamin E and isoflavones bioaccessibility of encapsulated product increased by up to 4.4-fold and 1.7-fold in the 60:40 formulations. Consuming 20 g of encapsulated vitamin E and 170 g of encapsulated isoflavones daily would be sufficient to meet the recommended intake.

The Role of Genistein and its Derivatives in Ovarian Cancer: New Perspectives for Molecular Mechanisms and Clinical Applications

Genistein (GEN) is a member of the polyphenol family, known chiefly for its effects on metabolic diseases and gynecological disorders. GEN has anti-cancer properties by inhibiting tumor proliferation, tumor metastasis, invasion, migration, and inducing apoptosis. Ovarian cancer (OC) is ranked 7th among the most common gynecological cancers. Despite its low incidence compared to other cancers, it is the first cause of death among gynecologic malignancies. Surgery and chemotherapy are the main options for treating this fatal cancer. Therefore, further investigations into GEN may aid in the discovery of novel therapeutics for preventing and/or treating OC. In this review, we aim to investigate the role of GEN in ovarian cancer. We investigate the anti-tumor effects of GEN on OC cell lines, including inducing apoptosis, suppressing tumor growth, and inhibiting metastasis. Also, we review the studies investigating GEN's roles as an adjuvant in therapeutic regimens with other chemotherapeutic agents (e.g., cisplatin, quercetin, and gemcitabine).

Dietary Polyphenols, Food Processing and Gut Microbiome: Recent Findings on Bioavailability, Bioactivity, and Gut Microbiome Interplay

Polyphenols are organic chemical compounds naturally present in plants, renowned for their anti-inflammatory, antioxidant, immunomodulatory, anticancer, and cardiovascular protective properties. Their bioactivity and bioavailability can vary widely depending on the methods of food processing and interactions with the gut microbiome. These factors can induce changes in polyphenols, affecting their ability to achieve their intended health benefits. Thus, it is essential to develop and apply food processing methods that optimize polyphenol content while maintaining their bioactivity and bioavailability. This review aims to explore how various food processing techniques affect the quantity, bioactivity, and bioavailability of polyphenols, as well as their interactions with the gut microbiome, which may ultimately determine their health effects.

Associations of urinary phytoestrogens with all-cause and cardiovascular mortality in adults: a population-based cohort study

Background

The overall understanding of the correlations between mortality risk and phytoestrogens in general population remains limited. We examined the association between urinary phytoestrogen levels and all-cause and cardiovascular mortality based on the National Health and Nutrition Examination Survey (NHANES).

Methods

Weighted Cox proportional hazard regression models were employed to calculate adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs). Nonlinear relationships were assessed using multivariable-adjusted restricted cubic splines (RCS).

Results

In the fully adjusted model, the highest quartiles of urinary genistein levels were correlated with significantly elevated all-cause (HR = 1.36, 95%CI: 1.16-1.59) and cardiovascular (HR = 1.58, 95%CI: 1.20-2.09) mortality. Urinary enterolactone levels in the third quartile were associated with reduced all-cause (HR = 0.77, 95%CI: 0.65-0.90) and cardiovascular (HR = 0.74, 95%CI: 0.55-0.99) mortality. In the highest quartiles of urinary daidzein levels, the cardiovascular mortality was significantly increased (HR = 1.44, 95%CI: 1.09-1.90). RCS showed an non-linear relationship between urinary daidzein levels and all-cause mortality (P = 0.04).

Conclusion

In the context of a nationally representative sample, genistein exhibited associations with elevated all-cause and cardiovascular mortality, whereas enterolactone showed an association with reduced mortality. The dose-response relationship between urinary daidzein levels and all-cause mortality as well as sex-specific disparities in the impact of phytoestrogen levels should be considered.

Flavonoid compounds and their synergistic effects: Promising approaches for the prevention and treatment of psoriasis with emphasis on keratinocytes - A systematic and mechanistic review

Psoriasis, a chronic autoimmune skin disorder, causes rapid and excessive skin cell growth due to immune system dysfunction. Numerous studies have shown that flavonoids have anti-psoriatic effects by modulating various molecular mechanisms involved in inflammation, cytokine production, keratinocyte proliferation, and more. This study reviewed experimental data reported in scientific literature and used network analysis to identify the potential biological roles of flavonoids' targets in treating psoriasis. 947 records from Web of Sciences, ScienceDirect database, Scopus, PubMed, and Cochrane library were reviewed without limitations until June 26, 2023. 66 articles were included in the systematic review. The ten genes with the highest scores, including interleukin (IL)-10, IL-12A, IL-1β, IL-6, Tumor necrosis factor-α (TNF-α), Janus kinase 2 (JAK 2), Jun N-terminal kinase (JUN), Proto-oncogene tyrosine-protein kinase Src (SRC), Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and Signal transducer and activator of transcription 3 (STAT3), were identified as the hub genes. KEGG pathway analysis identified connections related to inflammation and autoimmune responses, which are key characteristics of psoriasis. IL-6, STAT3, and JUN's presence in both hub and enrichment genes suggests their important role in flavonoid's effect on psoriasis. This comprehensive study highlights how flavonoids can target biological processes in psoriasis, especially when combined for enhanced effectiveness.

Dietary biomarkers-an update on their validity and applicability in epidemiological studies

The aim of this literature review was to identify and provide a summary update on the validity and applicability of the most promising dietary biomarkers reflecting the intake of important foods in the Western diet for application in epidemiological studies. Many dietary biomarker candidates, reflecting intake of common foods and their specific constituents, have been discovered from intervention and observational studies in humans, but few have been validated. The literature search was targeted for biomarker candidates previously reported to reflect intakes of specific food groups or components that are of major importance in health and disease. Their validity was evaluated according to 8 predefined validation criteria and adapted to epidemiological studies; we summarized the findings and listed the most promising food intake biomarkers based on the evaluation. Biomarker candidates for alcohol, cereals, coffee, dairy, fats and oils, fruits, legumes, meat, seafood, sugar, tea, and vegetables were identified. Top candidates for all categories are specific to certain foods, have defined parent compounds, and their concentrations are unaffected by nonfood determinants. The correlations of candidate dietary biomarkers with habitual food intake were moderate to strong and their reproducibility over time ranged from low to high. For many biomarker candidates, critical information regarding dose response, correlation with habitual food intake, and reproducibility over time is yet unknown. The nutritional epidemiology field will benefit from the development of novel methods to combine single biomarkers to generate biomarker panels in combination with self-reported data. The most promising dietary biomarker candidates that reflect commonly consumed foods and food components for application in epidemiological studies were identified, and research required for their full validation was summarized.

A Gnotobiotic Mouse Model with Divergent Equol-Producing Phenotypes: Potential for Determining Microbial-Driven Health Impacts of Soy Isoflavone Daidzein

The implications of soy consumption on human health have been a subject of debate, largely due to the mixed evidence regarding its benefits and potential risks. The variability in responses to soy has been partly attributed to differences in the metabolism of soy isoflavones, compounds with structural similarities to estrogen. Approximately one-third of humans possess gut bacteria capable of converting soy isoflavone daidzein into equol, a metabolite produced exclusively by gut microbiota with significant estrogenic potency. In contrast, lab-raised rodents are efficient equol producers, except for those raised germ-free. This discrepancy raises concerns about the applicability of traditional rodent models to humans. Herein, we designed a gnotobiotic mouse model to differentiate between equol producers and non-producers by introducing synthetic bacterial communities with and without the equol-producing capacity into female and male germ-free mice. These gnotobiotic mice display equol-producing phenotypes consistent with the capacity of the gut microbiota received. Our findings confirm the model's efficacy in mimicking human equol production capacity, offering a promising tool for future studies to explore the relationship between endogenous equol production and health outcomes like cardiometabolic health and fertility. This approach aims to refine dietary guidelines by considering individual microbiome differences.

Effect of the Fermented Soy Q-CAN® Product on Biomarkers of Inflammation and Oxidation in Adults with Cardiovascular Risk, and Canonical Correlations between the Inflammation Biomarkers and Blood Lipids

Systemic low-grade inflammation plays a key role in the development of cardiovascular disease (CVD) but the process may be modulated by consuming fermented soy foods. Here, we aim to evaluate the effect of a fermented soy powder Q-CAN^® on inflammatory and oxidation biomarkers in subjects with cardiovascular risk. In a randomized crossover trial, 27 adults (mean age ± SD, 51.6 ± 13.5 y) with a mean BMI ± SD of 32.3 ± 7.3 kg/m² consumed 25 g daily of the fermented soy powder or an isoenergic control powder of sprouted brown rice for 12 weeks each. Between-treatment results showed a 12% increase in interleukin-1 receptor agonist (IL-1Ra) in the treatment group, whereas within-treatment results showed 23% and 7% increases in interleukin-6 (IL-6) and total antioxidant status (TAS), respectively. The first canonical correlation coefficient (r = 0.72) between inflammation markers and blood lipids indicated a positive association between high-sensitivity C-reactive protein (hsCRP) and IL-1Ra with LDL-C and a negative association with HDL-C that explained 62% of the variability in the biomarkers. These outcomes suggest that blood lipids and inflammatory markers are highly correlated and that ingestion of the fermented soy powder Q-CAN^® may increase IL-1Ra, IL-6, and TAS in individuals with CVD risk factors.

Polyphenols—Ensured Accessibility from Food to the Human Metabolism by Chemical and Biotechnological Treatments

Polyphenols are plant-based compounds famous for their positive impact on both human health and the quality of food products. The benefits of polyphenols are related to reducing cardiovascular diseases, cholesterol management, cancers, and neurological disorders in humans and increasing the shelf life, management of oxidation, and anti-microbial activity in food products. The bioavailability and bio-accessibility of polyphenols are of the highest importance to secure their impact on human and food health. This paper summarizes the current state-of-the-art approaches on how polyphenols can be made more accessible in food products to contribute to human health. For example, by using food processing methods including various technologies, such as chemical and biotechnological treatments. Food matrix design and simulation procedures, in combination with encapsulation of fractionated polyphenols utilizing enzymatic and fermentation methodology, may be the future technologies to tailor specific food products with the ability to ensure polyphenol release and availability in the most suitable parts of the human body (bowl, intestine, etc.). The development of such new procedures for utilizing polyphenols, combining novel methodologies with traditional food processing technologies, has the potential to contribute enormous benefits to the food industry and health sector, not only reducing food waste and food-borne illnesses but also to sustain human health.

Isoflavone Metabolism by Lactic Acid Bacteria and Its Application in the Development of Fermented Soy Food with Beneficial Effects on Human Health

Isoflavones are phenolic compounds (considered as phytoestrogens) with estrogenic and antioxidant function, which are highly beneficial for human health, especially in the aged population. However, isoflavones in foods are not bioavailable and, therefore, have low biological activity. Additionally, their transformation into bioactive compounds by microorganisms is necessary to obtain bioavailable isoflavones with beneficial effects on human health. Many lactic acid bacteria (LAB) can transform the methylated and glycosylated forms of isoflavones naturally present in foods into more bioavailable aglycones, such as daidzein, genistein and glycitein. In addition, certain LAB strains are capable of transforming isoflavone aglycones into compounds with a greater biological activity, such as dihydrodaidzein (DHD), O-desmethylangolensin (O-DMA), dihydrogenistein (DHG) and 6-hydroxy-O-desmethylangolensin (6-OH-O-DMA). Moreover, Lactococcus garviae 20-92 is able to produce equol. Another strategy in the bioconversion of isoflavones is the heterologous expression of genes from Slackia isoflavoniconvertens DSM22006, which have allowed the production of DHD, DHG, equol and 5-hydroxy-equol in high concentrations by engineered LAB strains. Accordingly, the consequences of isoflavone metabolism by LAB and its application in the development of foods enriched in bioactive isoflavones, as well as health benefits attributed to their consumption, will be addressed in this work.

The effects of soymilk plus probiotics supplementation on cardiovascular risk factors in patients with type 2 diabetes mellitus: a randomized clinical trial

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiovascular diseases. This study aimed to assess the effects of soymilk plus probiotics co-administration on cardiovascular risk factors in T2DM patients.

METHODS

One hundred patients with T2DM (aged 40-75 years old) were randomly assigned into 4 groups (soymilk + probiotics supplement, soymilk + placebo, conventional milk + placebo, and probiotics supplement) for 6 weeks. Standard protocols were followed for the collection of fasting blood samples, dietary intakes, and anthropometric measurements.

RESULTS

It was shown that soymilk + probiotics consumption significantly decreased diastolic blood pressure (DBP) (p = 0.001), triglycerides (TG) (P < 0.001), total cholesterol (TC) (p < 0.01), and insulin (P < 0.003) levels and significantly increased high-density lipoprotein cholesterol (HDL-C) (P = 0.002) levels. Soymilk + placebo administration significantly decreased DBP (p = 0.01), insulin (p = 0.006), and TG (p = 0.001) levels and significantly increased HDL-C (p = 0.03) levels. A significant decrease in insulin (p = 0.003) and systolic blood pressure (SBP) (p = 0.01) levels and an increase in HDL-C (p = 0.04) levels were observed after supplementation with probiotics. Findings from between-group comparisons showed a significant decrease in SBP levels in the probiotics supplement group compared to conventional milk group (p < 0.05).

CONCLUSION

Soymilk and probiotics consumption might improve some cardiovascular risk factors in patients with T2DM. However, possible synergic effects while consumption of soymilk plus probiotics supplement didn't show in this study which warranted further research.

Biscuits Prepared with Enzymatically-Processed Soybean Meal Are Rich in Isoflavone Aglycones, Sensorially Well-Accepted and Stable during Storage for Six Months

Soybean meal (SBM) is a co-product of the soybean oil industry that is rich in bioactive compounds, such as isoflavones. We aimed to study the effects of processing SBM by fermentation (Saccharomyces cerevisiae) (FSBM) and enzymatic hydrolysis (CelluMax C, a commercial cellulase) (ESBM) on its chemical composition, with emphasis on isoflavones. Fermentation increased protein content by 9%, ash content by 7%, dietary fiber by 11% and minerals by up to 38%, except for iron, which decreased by 26%. Fermentation completely removed oligosaccharides from SBM, while enzymatic processing decreased oligosaccharides by 45% in SBM. Both processes converted glycosylated isoflavones into the corresponding aglycones, the content of which increased by up to 7.7-fold. Biscuits containing SBM, FSBM and ESBM could be labeled as dietary sources of dietary fibers, potassium, phosphorous, calcium and zinc, as well as high in proteins, copper, iron, manganese and magnesium. While FSBM biscuits had lower sensory scores compared to SBM biscuits, ESBM biscuits had equivalent scores. During storage for 180 days at room temperature, the isoflavone profile of all biscuits remained stable. Moreover, storage did not impair microbiological and sensory qualities of any biscuits. Altogether, ESBM biscuits show great marketing potential.

Optimizing pre-treatment of alkaline hydrolysis RP-HPLC for enhancing accuracy of soy isoflavone determination

Isoflavones (IFs) are important bioactive compounds which offers several benefits to human health. Despite the importance of IFs content, there are still some deficiencies in the existing methods. The objective of this study is to optimize key parameters of alkaline hydrolysis method for enhancing both reliability and accuracy of quantitative analysis of IFs contents in soybeans and soy protein products. Solvent type, extraction temperature, heating mode, alkaline concentration, hydrolysis temperature, hydrolysis time and some details are key points to target analytes which yield determining parameters. The biggest IFs content was obtained by extraction using methanol (MeOH)/water (80:20, v/v) in a 75 ℃ oven for 2 h, and hydrolyzation with 3 M NaOH solution at a room temperature for 10 mins. The total IFs content obtained by the improved method has increased by 16.4% compared with AOAC Official Method 2001.10. The accuracy of the method was evaluated using the relative standard deviation (RSD). Intraday accuracies in the total amount of isoflavones of four samples were 0.03%-0.63% (n = 3). Interday accuracy in the total amount of isoflavones was 2.71% (n = 6). LOD of IFs ranged from 0.1μg/mL for aglycones to 0.2μg/mL for glucosides. LOQ of IFs ranged from 0.3μg/mL for aglycones to 0.5μg/mL for glucosides. The improved method was proven to be a more accurate way to determine IFs contents in soybeans and soy protein products and thus making it useful for quality control and systematic in-depth study of soybeans and soy products; even to further assess the dietary soy exposure and the soy-health association.

Effect of food processing on antioxidants, their bioavailability and potential relevance to human health

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Processing alters the amount, matrix interaction, and structure of antioxidants.

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It is not easy to dissociate processing effects from food matrix effects.

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It is still difficult to make general statements on the effects of processing on bioavailability.

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Facilitated release by heat, pressure, etc. contributes to increased bioaccessibility.

It has long been recognized that the antioxidants present in fresh plant materials may be very different to those we ingest via our foods. This is often due to the use of food processing strategies involving thermal/non-thermal treatments. Current research mostly focuses on determining what is present in vegetative starting materials; how this is altered during processing; how this influences activity in the gut and following uptake into bloodstream; and which in vivo physiological effects this may have on human body. Having a better understanding of these different steps and their importance in a health-and-nutrition-context will place us in a better position to breed for improved crop varieties and to advise the food industry on how to optimize processing strategies to enhance biochemical composition of processed foods. This review provides an overview of what is currently known about the influence which food processing treatments can have on antioxidants and gives some pointers as to their potential relevance.

Technological and Biotechnological Processes To Enhance the Bioavailability of Dietary (Poly)phenols in Humans

The health effects of (poly)phenols (PPs) depend upon their bioavailability that, in general, is very low and shows a high interindividual variability. The low bioavailability of PPs is mainly attributed to their low absorption in the upper gastrointestinal tract as a result of their low water solubility, their presence in foods as polymers or in glycosylated forms, and their tight bond to food matrices. Although many studies have investigated how technological and biotechnological processes affect the phenolic composition of fruits and vegetables, limited information exists regarding their effects on PP bioavailability in humans. In the present review, the effect of food processing (mechanical, thermal, and non-thermal treatments), oral-delivery nanoformulations, enzymatic hydrolysis, fermentation, co-administration with probiotics, and generation of postbiotics in PP bioavailability have been overviewed, focusing in the evidence provided in humans.

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.

Strategies to achieve significant physiological concentrations of bioactive phytoestrogens in plasma

The benefits to health attributed to the intake of phytoestrogens (PEs) have been demonstrated in previous studies with significant physiological concentrations of bioactive PEs, such as genistein, equol, enterolignans and urolithins in plasma. However, the achievement of high bioactive PE levels in plasma is restricted to a select population group, mainly due to the low intake of plant PEs and/or the absence, or inhibition, of the microbiota capable of producing these bioactive forms. In this study, the intake of plant PEs, the concentration of bioactive PEs in plasma, the ability of the intestinal microbiota to produce bioactive PEs, as well as the different mechanisms used by GRAS bacteria to increase the level of bioactive PEs were evaluated concluding that the use of GRAS bacteria bioactive PE producers and the development of fermented foods enriched in bioactive PEs in addition to a high intake of plant PEs and taking care of the intestinal microbiota, are some of the different strategies to achieve significant physiological concentrations of bioactive PEs in the intestine and, subsequently, in plasma and targets organs which are essential to improve menopausal symptoms or reduce the risk of some pathologies such as breast and colon cancer, or cardiovascular disease.

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.

Optimization of the Bioactivation of Isoflavones in Soymilk by Lactic Acid Bacteria

Soybeans and soy-based products contain isoflavones which can be used for nutraceutical and medical applications. In soybeans and in unfermented soy foods, isoflavones are normally present as glycosides. Isoflavone glycosides can be enzymatically converted to isoflavone aglycones, thus releasing the sugar molecule. The effective absorption of isoflavones in humans requires the bioconversion of isoflavone glycosides to isoflavone aglycones through the activity of the enzyme β-glucosidase. The objective was to assess the capacity of 42 bacterial strains (belonging to Lactobacillus, Streptococcus and Enterococcus) to produce β-glucosidase activity. The strain that showed the highest β-glucosidase activity (Lactobacillus plantarum 128/2) was then used for the optimization of the bioconversion of genistin and daidzin present in commercial soymilk to their aglycone forms genistein and daidzein. The contribution of process parameters (temperature, inoculum size, time) to the efficiency of such bioactivation was tested. Lactobacillus plantarum 128/2 was able to completely bioactivate soymilk isoflavones under the following conditions: 25 °C temperature, 2% inoculum size and 48 h process time. These results confirm the suitability of lactic acid bacteria for the bioactivation of isoflavones present in soymilk and provide an interesting candidate (L. plantarum 182/2) for food industries to perform this transformation.

An Overview on Dietary Polyphenols and Their Biopharmaceutical Classification System (BCS)

Polyphenols are natural organic compounds produced by plants, acting as antioxidants by reacting with ROS. These compounds are widely consumed in daily diet and many studies report several benefits to human health thanks to their bioavailability in humans. However, the digestion process of phenolic compounds is still not completely clear. Moreover, bioavailability is dependent on the metabolic phase of these compounds. The LogP value can be managed as a simplified measure of the lipophilicity of a substance ingested within the human body, which affects resultant absorption. The biopharmaceutical classification system (BCS), a method used to classify drugs intended for gastrointestinal absorption, correlates the solubility and permeability of the drug with both the rate and extent of oral absorption. BCS may be helpful to measure the bioactive constituents of foods, such as polyphenols, in order to understand their nutraceutical potential. There are many literature studies that focus on permeability, absorption, and bioavailability of polyphenols and their resultant metabolic byproducts, but there is still confusion about their respective LogP values and BCS classification. This review will provide an overview of the information regarding 10 dietarypolyphenols (ferulic acid, chlorogenic acid, rutin, quercetin, apigenin, cirsimaritin, daidzein, resveratrol, ellagic acid, and curcumin) and their association with the BCS classification.

Preventive Applications of Polyphenols in Dentistry-A Review

Polyphenols are natural substances that have been shown to provide various health benefits. Antioxidant, anti-inflammatory, and anti-carcinogenic effects have been described. At the same time, they inhibit the actions of bacteria, viruses, and fungi. Thus, studies have also examined their effects within the oral cavity. This review provides an overview on the different polyphenols, and their structure and interactions with the tooth surface and the pellicle. In particular, the effects of various tea polyphenols on bioadhesion and erosion have been reviewed. The current research confirms that polyphenols can reduce the growth of cariogenic bacteria. Furthermore, they can decrease the adherence of bacteria to the tooth surface and improve the erosion-protective properties of the acquired enamel pellicle. Tea polyphenols, especially, have the potential to contribute to an oral health-related diet. However, in vitro studies have mainly been conducted. In situ studies and clinical studies need to be extended and supplemented in order to significantly contribute to additive prevention measures in caries prophylaxis.

A systematic review to identify biomarkers of intake for fermented food products

Background

Fermented foods are ubiquitous in human diets and often lauded for their sensory, nutritious, and health-promoting qualities. However, precise associations between the intake of fermented foods and health have not been well-established. This is in part due to the limitations of current dietary assessment tools that rely on subjective reporting, making them prone to memory-related errors and reporting bias. The identification of food intake biomarkers (FIBs) bypasses this challenge by providing an objective measure of intake. Despite numerous studies reporting on FIBs for various types of fermented foods and drinks, unique biomarkers associated with the fermentation process (“fermentation-dependent” biomarkers) have not been well documented. We therefore conducted a comprehensive, systematic review of the literature to identify biomarkers of fermented foods commonly consumed in diets across the world.

Results

After title, abstract, and full-text screening, extraction of data from 301 articles resulted in an extensive list of compounds that were detected in human biofluids following the consumption of various fermented foods, with the majority of articles focusing on coffee (69), wine (69 articles), cocoa (62), beer (34), and bread (29). The identified compounds from all included papers were consolidated and sorted into FIBs proposed for a specific food, for a food group, or for the fermentation process. Alongside food-specific markers (e.g., trigonelline for coffee), and food-group markers (e.g., pentadecanoic acid for dairy intake), several fermentation-dependent markers were revealed. These comprised compounds related to the fermentation process of a particular food, such as mannitol (wine), 2-ethylmalate (beer), methionine (sourdough bread, cheese), theabrownins (tea), and gallic acid (tea, wine), while others were indicative of more general fermentation processes (e.g., ethanol from alcoholic fermentation, 3-phenyllactic acid from lactic fermentation).

Conclusions

Fermented foods comprise a heterogeneous group of foods. While many of the candidate FIBs identified were found to be non-specific, greater specificity may be observed when considering a combination of compounds identified for individual fermented foods, food groups, and from fermentation processes. Future studies that focus on how fermentation impacts the composition and nutritional quality of food substrates could help to identify novel biomarkers of fermented food intake.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12263-021-00686-4.

Neither soyfoods nor isoflavones warrant classification as endocrine disruptors: a technical review of the observational and clinical data

Soybeans are a rich source of isoflavones, which are classified as phytoestrogens. Despite numerous proposed benefits, isoflavones are often classified as endocrine disruptors, based primarily on animal studies. However, there are ample human data regarding the health effects of isoflavones. We conducted a technical review, systematically searching Medline, EMBASE, and the Cochrane Library (from inception through January 2021). We included clinical studies, observational studies, and systematic reviews and meta-analyses (SRMA) that examined the relationship between soy and/or isoflavone intake and endocrine-related endpoints. 417 reports (229 observational studies, 157 clinical studies and 32 SRMAs) met our eligibility criteria. The available evidence indicates that isoflavone intake does not adversely affect thyroid function. Adverse effects are also not seen on breast or endometrial tissue or estrogen levels in women, or testosterone or estrogen levels, or sperm or semen parameters in men. Although menstrual cycle length may be slightly increased, ovulation is not prevented. Limited insight could be gained about possible impacts of in utero isoflavone exposure, but the existing data are reassuring. Adverse effects of isoflavone intake were not identified in children, but limited research has been conducted. After extensive review, the evidence does not support classifying isoflavones as endocrine disruptors.

The Anti-Inflammatory Properties of Phytochemicals and Their Effects on Epigenetic Mechanisms Involved in TLR4/NF-κB-Mediated Inflammation

Innate immune response induces positive inflammatory transducers and regulators in order to attack pathogens, while simultaneously negative signaling regulators are transcribed to maintain innate immune homeostasis and to avoid persistent inflammatory immune responses. The gene expression of many of these regulators is controlled by different epigenetic modifications. The remarkable impact of epigenetic changes in inducing or suppressing inflammatory signaling is being increasingly recognized. Several studies have highlighted the interplay of histone modification, DNA methylation, and post-transcriptional miRNA-mediated modifications in inflammatory diseases, and inflammation-mediated tumorigenesis. Targeting these epigenetic alterations affords the opportunity of attenuating different inflammatory dysregulations. In this regard, many studies have identified the significant anti-inflammatory properties of distinct naturally-derived phytochemicals, and revealed their regulatory capacity. In the current review, we demonstrate the signaling cascade during the immune response and the epigenetic modifications that take place during inflammation. Moreover, we also provide an updated overview of phytochemicals that target these mechanisms in macrophages and other experimental models, and go on to illustrate the effects of these phytochemicals in regulating epigenetic mechanisms and attenuating aberrant inflammation.

Fermented Soybean Meal Affects the Reproductive Performance and Oxidative Status of Sows, and the Growth of Piglets

Simple Summary

Fermentation of the cooked soybean meal increases the contents of isoflavone aglycones, provides soy proteins that are easier to absorb and eliminates trypsin inhibitors in soybean meal. In the present study, replacing soybean meal in the maternal diet with fermented soybean meal decreased the oxidative stress in the serum of sows and increased the average body weight of piglets on the 14th day and the 21st day after birth. We concluded that replacing the soybean meal in the maternal diet with the fermented soybean meal attenuates the oxidative stress status of the gestational and lactational sows, and enhances the average weight of their offspring.

Abstract

This study aimed to investigate the effect of the fermented soybean meal on the reproductive performance, oxidative stress and colostrum composition of sows, and the growth performance of their progeny. A total of 44 sows were allotted to four dietary groups (n = 11/group). The dietary groups included the basal diet group (control) and the treatment groups in which soybean meal in the basal diet was replaced with 2%, 4%, and 6% fermented soybean meal, respectively. The experimental diets were fed to the sows from the 78th day of gestation to the 21st day of lactation. Replacing soybean meal in the basal maternal diet with the fermented soybean meal decreased the levels of malondialdehyde, cortisol, and 8-iso-prostaglandinF2α in the serum of sows and increased the average weight of piglets on the 14th day and the 21st day after birth. The activity of superoxide dismutase in the serum of sows was increased in the group with 4% fermented soybean meal on the 17th day of lactation. The levels of estrogen and growth factors in the serum of sows were enhanced in the group with 6% fermented soybean meal. In the colostrum, the levels of the protein and the immunoglobulin G were enhanced in the group with 4% fermented soybean meal. In conclusion, replacing the soybean meal in the basal maternal diet with the fermented soybean meal attenuates the oxidative stress status of the gestational and lactational sows, and enhances the average weight of their offspring.

Molecular mechanism and pharmacokinetics of flavonoids in the treatment of resistant EGF receptor-mutated non-small-cell lung cancer: A narrative review

Here, we review the molecular mechanism and pharmacokinetics of flavonoids in the treatment of resistant EGF receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) and particularly the possible mechanism(s) of delicaflavone, a biflavonoid extracted from Selaginella doederleinii Hieron. EGFR TK inhibitors (EGFR-TKI) are ubiquitously used in the treatment of NSCLC bearing EGFR mutations. However, patients treated with EGFR-TKI inevitably and continuously develop resistance. In laboratory studies, flavonoids, as potential adjuvants for cancer chemotherapy, exhibited anti-cancer properties such as inhibition of chemoresistance by interference with ABC transporters-induced drug efflux, curbing of c-MET amplification, or reversal of T790M mutation-mediated resistance. The current review aims at summarizing the association between the anti-cancer potentials of flavonoids and their possible regulatory roles in certain types of mutation that could trigger EGFR-TKI resistance in NSCLC. Potential practical applications of these phytochemicals, as well as the relevant pharmacokinetics, are also discussed.

A Non-Probiotic Fermented Soy Product Reduces Total and LDL Cholesterol: A Randomized Controlled Crossover Trial

Traditional Asian fermented soy food products are associated with reduced cardiovascular disease risk in prospective studies, but few randomized controlled trials have been conducted in at-risk populations. The aim of this study was to investigate the effect of a commercial non-probiotic fermented soy product on blood lipids in adults with cardiovascular risk biomarkers. In a randomized, crossover, intervention study, 27 men and women (aged 29–75 y) exhibiting at least two risk factors, consumed two packets (12.5 g each) daily of a fermented powdered soy product, or an isoenergic control powder made from germinated brown rice for 12 weeks each. The consumption of the fermented soy product resulted in a significantly greater mean change from baseline (compared to the germinated rice, all p < 0.05) in total cholesterol of −0.23 mmol/L (CI: −0.40, −0.06) compared with 0.14 mmol/L (CI: −0.03, 0.31), respectively; and low density lipoprotein (LDL) cholesterol −0.18 mmol/L (CI: −0.32, −0.04) compared with 0.04 mmol/L (CI: −0.01, 0.018) respectively. This was accompanied by an increase in high density lipoprotein (HDL) cholesterol in the germinated rice group, a decrease in apolipoprotein B (ApoB) in the fermented soy group, and a between-treatment effect in apolipoprotein A1 (ApoA1); however, the ratio of the LDL:HDL and of Apo B:ApoA1 did not differ between the groups. The ratio of total cholesterol:LDL decreased in men in the fermented soy group (p < 0.001). Twenty-four-hour urine collection at the end of each treatment period resulted in an increased excretion expressed as a ratio in μmol/d between treatments of 10.93 (CI: 5.07, 23.54) for daidzein; 1.24 (CI: 1.14, 4.43) for genistein; and, 8.48 (CI: 4.28, 16.80) for glycitein, all p < 0.05. The fermented soy powder consumed by participants in this study without implementing other changes in their typical diets, decreased the total and LDL cholesterol, and may serve as a dietary strategy to manage blood lipids. The trial was registered at ClinicalTrials.gov as NCT03429920.

Validation of soy isoflavone intake and its health effects: a review of the development of exposure biomarkers

BACKGROUND/OBJECTIVES

It is difficult to consistently demonstrate the health effects of soy isoflavones owing to the multitude of factors contributing to their bioavailability. To accurately verify these health effects, dietary isoflavone intake should be measured using a biologically active dose rather than an intake dose. This concept has been expanded to the development of new exposure biomarkers in nutrition research. This review aims to provide an overview of the development of exposure biomarkers and suggest a novel research strategy for identifying the health effects of soy isoflavone intake.

MATERIALS/METHODS

We cover recent studies on the health effects of soy isoflavones focusing on isoflavone metabolites as exposure biomarkers.

RESULTS

Compared to non-fermented soy foods, fermented soy foods cause an increased concentration of isoflavones in the biofluid immediately following ingestion. The correlation between exposure biomarkers in blood and urine and the food frequency questionnaire was slightly lower than that of corresponding 24-h dietary recalls. Urinary and blood isoflavone levels did not show a consistent association with chronic disease and cancer risk.

CONCLUSION

It is crucial to understand the variable bioavailabilities of soy isoflavones, which may affect evaluations of soy isoflavone intake in health and disease. Further studies on the development of valid exposure biomarkers are needed to thoroughly investigate the health effects of isoflavone.

Streptococcus thermophilus growth in soya milk: Sucrose consumption, nitrogen metabolism, soya protein hydrolysis and role of the cell-wall protease PrtS

Societal demand for plant-based foods is increasing. In this context, soya products fermented using lactic acid bacteria (LAB) are appealing because of their potential health and nutritional benefits. The thermophilic LAB Streptococcus thermophilus is an essential starter species in the dairy industry. However, while its physiology is well characterized, little is known about its general metabolic activity or its techno-functional properties when it is grown in soya milk. In this study, S. thermophilus LMD-9 growth, sugar production, and lactic acid production in soya milk versus cow's milk were measured. Additionally, the main metabolic pathways used by the bacterium when growing in soya milk were characterized using a proteomic approach. Streptococcus thermophilus LMD-9 growth decreased soya milk pH, from 7.5 to 4.9, in 5 h. During fermentation, acidification thus occurred in tandem with lactate production and increasing population size (final population: 1.0 × 10⁹ CFU/ml). As growth proceeded, sucrose was consumed, and fructose was produced. The proteomic analysis (LC-MS/MS) of the strain's cytosolic and cell envelope-associated proteins revealed that proteins related to amino acid transport and nitrogen metabolism were the most common among the 328 proteins identified (63/328 = 19.2% of total proteins). The cell-wall protease PrtS was present, and an LMD-9 deletion mutant was constructed by interrupting the prtS gene (STER_RS04165 locus). Acidification levels, growth levels, and final population size were lower in the soya milk cultures when the ΔprtS strain versus the wild-type (wt) strain was used. The SDS-PAGE profile of the soluble proteins in the supernatant indicated that soya milk proteins were less hydrolyzed by the ΔprtS strain than by the wt strain. It was discovered that S. thermophilus can grow in soya milk by consuming sucrose, can hydrolyze soya proteins, and can produce acidification levels comparable to those in cow's milk. This study comprehensively examined the proteomics of S. thermophilus grown in soya milk and demonstrated that the cell-wall protease PrtS is involved in the LAB's growth in soya milk and in the proteolysis of soya proteins, which are two novel findings. These results clarify how S. thermophilus adapts to soya milk and can help inform efforts to develop new fermented plant-based foods with better-characterized biochemical and microbiological traits.

Medicinal Potential of Isoflavonoids: Polyphenols That May Cure Diabetes

In recent years, there is emerging evidence that isoflavonoids, either dietary or obtained from traditional medicinal plants, could play an important role as a supplementary drug in the management of type 2 diabetes mellitus (T2DM) due to their reported pronounced biological effects in relation to multiple metabolic factors associated with diabetes. Hence, in this regard, we have comprehensively reviewed the potential biological effects of isoflavonoids, particularly biochanin A, genistein, daidzein, glycitein, and formononetin on metabolic disorders and long-term complications induced by T2DM in order to understand whether they can be future candidates as a safe antidiabetic agent. Based on in-depth in vitro and in vivo studies evaluations, isoflavonoids have been found to activate gene expression through the stimulation of peroxisome proliferator-activated receptors (PPARs) (α, γ), modulate carbohydrate metabolism, regulate hyperglycemia, induce dyslipidemia, lessen insulin resistance, and modify adipocyte differentiation and tissue metabolism. Moreover, these natural compounds have also been found to attenuate oxidative stress through the oxidative signaling process and inflammatory mechanism. Hence, isoflavonoids have been envisioned to be able to prevent and slow down the progression of long-term diabetes complications including cardiovascular disease, nephropathy, neuropathy, and retinopathy. Further thoroughgoing investigations in human clinical studies are strongly recommended to obtain the optimum and specific dose and regimen required for supplementation with isoflavonoids and derivatives in diabetic patients.

Metabolic tracking of isoflavones in soybean products and biosamples from healthy adults after fermented soybean consumption

Fermentation may enhance the nutritional properties of foods by increasing metabolite bioactivity or bioavailability. This study explored the effect of fermentation on isoflavone bioavailability and metabolism. Isoflavone metabolites were tracked in foods and biospecimens of healthy adults after fermented soybean (FS) or non-fermented soybean (NFS) consumption in a randomized, controlled, crossover intervention study. The change in soybean isoflavones caused by fermentation resulted in faster absorption and higher bioavailability after consumption of FS. Although the urinary level of total isoflavone metabolites was similar after the consumption of the two diets, urinary genistein 7-O-sulfate was derived as a discriminant metabolite for the FS diet by partial least squares discriminant analysis. This study suggests that an isoflavone conjugate profile might be a more appropriate marker than total isoflavone levels for discriminating between the consumption of FS and NFS diets.

Evaluation of the status quo of polyphenols analysis: Part II-Analysis methods and food processing effects

Nowadays due to the concern with the environmental impact of analytical techniques and in order to reduce the ecological footprint there is a tendency to use more efficient and faster procedures that use a smaller amount of organic solvents. Polyphenols have been widely studied in plant-based matrices due to their wide and potent biological properties; however there are no standardized procedures both for sample preparation and analysis of these compounds. The second of a two-part review will carry out a critical review of the extraction procedures and analytical methods applied to polyphenols and their selection criteria over a wide range of factors in relation to commerce-associated, environmental, and economic factors. It is foreseen that in the future the analysis of polyphenols in plant-based matrices includes the use of techniques that allow the simultaneous determination of different subclasses of polyphenols using fast, sophisticated, and automated techniques that allow the minimal consumption of solvents.

Diversity of the metabolic profiles of a broad range of lactic acid bacteria in soy juice fermentation

This study explores the ability of lactic acid bacteria (LAB) to ferment soy juice. The ability of 276 LAB strains from 25 species to ferment the principal soy carbohydrates, sucrose, raffinose or stachyose was tested in synthetic media and a soy juice. Fermented soy juices (FSJs) were characterized for their odor. Selected FSJs were characterized by targeted metabolomics. All Streptococcus, 83% of Leuconostoc and Lactobacillus and 41% of Lactococcus strains were sucrose-positive, while only 36% of all the LAB strains tested were raffinose-positive and 6% stachyose-positive. Nearly all (97%) the sucrose-positive strains fermented soy juice, indicating that an ability to use sucrose is a good criterion to select strains for soy juice fermentation. Among the most efficient acidifying strains, 46 FSJs had an odor deemed to be acceptable. FSJ composition was dependent on both species and strains: 17/46 strains deglycosylated soy juice isoflavones, the 27 S. thermophilus strains converted a mean 4.4 ± 0.1 g/L of sucrose into 3.0 ± 0.1 g/L of lactic acid versus 5.2 ± 0.1 g/L into 2.2 ± 0.1 g/L for the 18 Lactobacillus and one Lactococcus strains. This study highlights the diversity of the metabolic profiles of LAB strains in soy juice fermentation.

Soy flavonoids prevent cognitive deficits induced by intra-gastrointestinal administration of beta-amyloid

BACKGROUND

In Alzheimer's diseases, beta-amyloid may act as prion-like protein and migrate from the gastrointestinal tract towards the brain. Soy flavonoids have been identified as neuroprotective against cognitive loss in human. Diet with soy flavonoids may be used to slow down the progression of Alzheimer's diseases.

METHODS AND RESULTS

We performed in-vitro tissue culture experiments using myenteric plexus longitudinal muscle layers isolated from the ileum and colon of ICR mice. Beta-amyloid can be taken up into myenteric neurons and induce neuron degeneration, which is protected by flavonoids compounds, including daidzein, genistein, glycitein and luteolin. We also administered oligomeric beta-amyloid (1-42) (total dose: 8 μg) into the gastrointestinal walls of ICR mice and conducted memory tests and gastrointestinal function assessments after 6 and 12 months. Mice treated with beta-amyloid exhibited minor learning deficits in a T-maze memory test at 6 months and significant memory impairment in a novel object recognition task at 12 months. These impairments were prevented by soy flavonoids. Tracking studies performed using fluorescently tagged beta-amyloid found that, beta-amyloid injected at the stomach can aggregate within the layer of myenteric neurons and migrate to the jejunum or via the vagus nerves to the brain after 1 month. Reductions in the gastrointestinal tissue weight and the spontaneous ileal contraction frequency were also observed at 6 and 12 months, respectively.

CONCLUSION

Our findings indicate that beta-amyloid can migrate from the gastrointestinal tract to the brain to induce cognitive impairments. Furthermore, chronic soy flavonoids in drinking water have protective actions.

Structure-bioavailability relationship study of genistein derivatives with antiproliferative activity on human cancer cell

The present study assesses the in vitro and in vivo bioavailability of genistein derivatives, hydroxyalkyl- and glycosyl alkyl ethers (glycoconjugates). Studies were carried out using compounds that exhibit higher in vitro antiproliferative activity in comparison with the parent isoflavone. Based on in vitro experiments using the Parallel Artificial Membrane Permeability Assay (PAMPA) and the Caco-2 cell monolayer permeability model, we found that modification of the isoflavone structure by O-alkylation improved bioavailability in comparison to genistein. Additionally, the structure of the substituent and its position on genistein influenced the type of mechanism involved in the transport of compounds through biological membranes. The PAMPA assay showed that the structure of glycoconjugates had a significant influence on the passive transport of the genistein synthetic derivatives through a biological membrane. Preferentially the glycoconjugates containing O-glycosidic bond were transported and the transport rate decreased as the carbon linker increased. For glycoconjugates, determination of their transport and metabolism through the Caco-2 membrane was not possible due to interaction with the membrane surface, probably by the change of compound structure caused by contact with the cells or degradation in medium. The intestinal absorption and metabolism of genistein and three derivatives, Ram-3, Ram'-3 and Ram-C-4α (Fig. 1), were tested in vivo in rats. We found that in comparison to genistein, glycoconjugates were metabolized more slowly and to a lesser extent. As part of the in vivo research, we performed analysis of compound levels in plasma samples after enzymatic hydrolysis, but in the collected samples, analytes were not observed. We hypothesize that glycoconjugates compounds bind plasma proteins and were removed from the sample. In conclusion, we show that O-functionalization of the natural, biologically active isoflavone genistein can affect biological activity, bioavailability, and the rate of compound metabolism. The position of the substituent, the length of the linker and the structure of sugar moieties provides a tool for the optimization of the derivative's biological properties.

Fermentation of soybean meal improves isoflavone metabolism after soy biscuit consumption by adults

BACKGROUND

Urinary excretion of isoflavones and their metabolites after the consumption of soybean meal (SBM) and fermented soybean meal (FSBM) biscuits was investigated in humans in a randomized double-blinded crossover clinical trial.

RESULTS

Aglycones were the most abundant metabolites in urine in both treatments. After FSBM consumption, total urinary excretion of aglycones and metabolites was 54% higher when compared to SBM biscuits. All metabolites were more rapidly excreted after FSBM biscuit consumption when compared to SBM biscuits. Urinary recovery of isoflavones was higher after FSBM biscuit consumption, reaching 67%. Women excreted higher amounts of colonic metabolites and lower amounts of aglycones than men. The prevalence of O-demethylangolensin-producer, equol-producer and nonproducer metabotypes was 56%, 11% and 36% after SBM consumption and 72%, 11% and 17% after FSBM consumption, respectively.

CONCLUSIONS

Together, our findings indicate that fermentation improves isoflavone bioavailability and possibly reduces the impact of gut microbiota on the metabolism of isoflavones. © 2020 Society of Chemical Industry.

Expression of a β-glucosidase in bacteria with biotechnological interest confers them the ability to deglycosylate lignans and flavonoids in vegetal foods

Lignans and flavonoids are found in plants in their glycosylated forms and need to be hydrolyzed to aglycones to become bioavailable. Putative β-glucosidase genes from Lactobacillus mucosae INIA P508 were inserted into the plasmid pNZ:TuR. The strain Lactococcus lactis MG1363 harboring the plasmid pNZ:TuR.glu913 showed high β-glucosidase activity and was able to transform secoisolariciresinol diglucoside (SDG) into secoisolariciresinol (SECO). Lactic acid bacteria and Bifidobacterium strains harboring pNZ:TuR.glu913 were incubated with a soy beverage supplemented with flax seed extracts. SDG was almost completely consumed by the transformed strains, while concentration of SECO greatly increased. Moreover, these strains showed high deglycosylation of the isoflavone glycosides daidzin and genistin. In addition, other lignan and flavonoid aglycones were produced, i.e. matairesinol, pinoresinol, quercetin, and eriodyctiol. These deglycosylase activities were maintained when this glucosidase gene was cloned in a food grade vector, pLEB590, and transformed into L. lactis MG1363. This is the first report of the use of a food grade plasmid that confers the ability to efficiently catalyze the deglycosylation of lignans, isoflavonoids, flavones, and flavanones. The recombinant bacteria of this study would be of value for the development of fermented vegetal foods enriched in bioavailable forms of lignans and flavonoids.

Physiological relevance of food antioxidants

Dietary antioxidants are associated with prevention of oxidative stress related chronic diseases including certain types of cancer, cardiovascular diseases, diabetes, and neurodegenerative diseases. In recent years, there has been a growing interest in extending the knowledge on their physiological effects in human body. There are numbers of epidemiological, clinical, meta-analysis, and in vitro studies to explain formation mechanisms of each chronic diseases as well as the potential effects of dietary antioxidants on these diseases and gut health. Comprehensive studies for food antioxidants' journey from dietary intake to target tissues/organs deserve a serious consideration to have a clear understanding on the physiological effects of dietary antioxidants. Therefore, absorption and metabolism of dietary antioxidants, and the factors affecting their absorption, such as solubility of antioxidants, food matrix, and interaction between antioxidants have been evaluated in several research articles. This chapter provides an overview about potential health effects of dietary antioxidants considering with their absorption and metabolism in human body.

Luteolin and luteolin-7-O-glucoside protect against acute liver injury through regulation of inflammatory mediators and antioxidative enzymes in GalN/LPS-induced hepatitic ICR mice

BACKGROUND/OBJECTIVES

Anti-inflammatory and antioxidative activities of luteolin and luteolin-7-O-glucoside were compared in galactosamine (GalN)/lipopolysaccharide (LPS)-induced hepatitic ICR mice.

MATERIALS/METHODS

Male ICR mice (6 weeks old) were divided into 4 groups: normal control, GalN/LPS, luteolin, and luteolin-7-O-glucoside groups. The latter two groups were administered luteolin or luteolin-7-O-glucoside (50 mg/kg BW) daily by gavage for 3 weeks after which hepatitis was induced by intraperitoneal injection of GalN and LPS (1 g/kg BW and 10 µg/kg BW, respectively).

RESULTS

GalN/LPS produced acute hepatic injury by a sharp increase in serum AST, ALT, and TNF-α levels, increases that were ameliorated in the experimental groups. In addition, markedly increased expressions of cyclooxygenase (COX)-2 and its transcription factors, nuclear factor (NF)-κB and activator protein (AP)-1, were also significantly attenuated in the experimental groups. Compared to luteolin-7-O-glucoside, luteolin more potently ameliorated the levels of inflammatory mediators. Phase II enzymes levels and NF-E2 p45-related factor (Nrf)-2 activation that were decreased by GalN/LPS were increased by luteolin and luteolin-7-O-glucoside administration. In addition, compared to luteolin, luteolin-7-O-glucoside acted as a more potent inducer of changes in phase II enzymes. Liver histopathology results were consistent with the mediator and enzyme results.

CONCLUSION

Luteolin and luteolin-7-O-glucoside protect against GalN/LPS-induced hepatotoxicity through the regulation of inflammatory mediators and phase II enzymes.

Effect of Genistein on Cholesterol Metabolism-Related Genes in HepG2 Cell

It has been reported that genistein could improve metabolic syndromes. Our study aimed to investigate the effects and potential mechanisms of genistein on improving cholesterol metabolism in HepG2 cell. HepG2 cells were cultured with 0, 0.01, 1.00, 10.00, and 50.00 µM genistein for 24 hr. The current results showed a dose-dependent manner between genistein and intracellular contents of total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), and cellular apolipoprotein A1 (Apo-A1) secretion. TC was increased by 25.69%, meanwhile HDL-C and Apo-A1 were decreased by 56.00% and 25.93%, respectively, when the dosage of genistein was 1.00 µM. Genistein dose-dependently upregulated the protein and mRNA levels of sterol regulatory element binding proteins-2 (SREBP-2), as well as the mRNA levels of low-density lipoprotein receptor (LDLR) and 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGCR), by 145.91%, 72.29%, 310.23%, and 123.08%, respectively, when we gave 1.00 µM genistein, indicating that intracellular cholesterol synthesis and absorption of exogenous cholesterol were increased. In addition, the mRNA levels of peroxisome proliferator-activated receptor-γ (PPARγ) and liver X receptor (LXRα), lowered by 58.23% and 34.86% at 0.01 µM genistein, were reduced in a dose-dependent manner. LXRα and ATP-binding cassette transporter A1 (ABCA1) protein levels were significantly (P < 0.05) decreased by 50.35% and 11.60% at 1.00 µM genistein, which indicated that cellular cholesterol efflux was inhibited. Taken together, our results suggested that genistein at dosage of more than 1.00 µM was able to increase the intracellular cholesterol levels by up regulating SREBP-2/LDLR/HMGCR pathway and suppressing PPARγ/LXRα/ABCA1 pathway. PRACTICAL APPLICATION: In this study, genistein appeared to be effective in reducing plasma cholesterol levels due to increase the intracellular cholesterol levels by upregulating cholesterol absorption through SREBP-2/LDLR/HMGCR pathway, and also downregulating cholesterol efflux via PPARγ/LXRα/ABCA1 pathway in vitro. In addition, plasma cholesterol is regarded as the key indicator of atherosclerosis; therefore, we believe that our findings could be used for further exploration on a possible therapeutic application of genistein for atherosclerosis.

Bifidobacterium breve MCC1274 with glycosidic activity enhances in vivo isoflavone bioavailability

Polyphenols are plant derived compounds that exert many beneficial health effects to the human host. However, associated health benefits of dietary polyphenol are highly dependent on their intestinal metabolism, bioavailability, and absorption. Bifidobacteria, which represent the key members of gut microbiota, have been suggested to promote gut microbial homeostasis and may be involved in the metabolism of polyphenols. In this study, the capabilities of thirteen Bifidobacterium strains in hydrolysing polyphenol glycosides were evaluated. Among the tested strains, Bifidobacterium breve MCC1274 was found to possess the highest β-glucosidase activity and strong capability to convert daidzin and trans-polydatin to their aglycones; while kinetic analysis revealed that B. breve MCC1274 hydrolysed more than 50% of daidzin and trans-polydatin at less than 3 h of incubation. Further investigation using rats with an antibiotics-disturbed microbiome revealed that following the ingestion of daidzin glycoside, oral administration of B. breve MCC1274 significantly enhanced the plasma concentration of daidzein in rats pre-treated with antibiotics as compared to antibiotics-pre-treated control and non-treated control groups. The relative abundance of Actinobacteria and the total numbers of B. breve were also significantly higher in antibiotics-pre-treated rats administered with B. breve MCC1274 than that of the control groups. These findings suggest that B. breve MCC1274 is effective in enhancing the bioavailability of daidzein in the gut under dysbiosis conditions and may potentially improve intestinal absorption of isoflavones and promote human health.

Antioxidant capacity of soymilk yogurt and exopolysaccharides produced by lactic acid bacteria

Reactive oxygen species (ROS), such as hydroxyl and superoxide anion radicals, are highly reactive molecules derived from the metabolism of oxygen. ROS play positive roles in cell physiology, but they may also damage cell membranes and DNA, inducing oxidation that causes membrane lipid peroxidation and decreases membrane fluidity. Soymilk yogurt, which is soymilk fermented using lactic acid bacteria (LAB), is an excellent food item with numerous functional substances with antioxidant effects. In this study, the antioxidative activities of soymilk yogurt were investigated. Sixteen of the 26 tested LAB strains solidified soymilk. In antioxidant capacity tests for bacterial cells, Leuconostoc mesenteroides MYU 60 and Pediococcus pentosaceus MYU 759 showed the highest values in the oxygen radical antioxidant capacity (ORAC) and hydroxyl radical antioxidant capacity (HORAC) tests, respectively. The supernatant of soymilk yogurt made with Lactobacillus gasseri MYU 1 showed the highest ORAC and HORAC values. L. mesenteroides MYU 60, Lactobacillus plantarum MYU 74, Lactobacillus reuteri MYU 220, and P. pentosaceus MYU 759 showed significantly high N-acetylcysteine equivalent values compared with the control in a total ROS reducing assay (p<0.05). These strains were selected, and a comet assay was performed, which exhibited decreased values in all selected strains compared with the control, indicating DNA protection. An acidic exopolysaccharide produced by P. pentosaceus MYU 759 showed high antioxidant capacity. The antioxidant substances produced by LAB fermentation may be exopolysaccharides, antioxidant peptides, and isoflavone aglycones. Soymilk yogurt can be used as a functional food useful for various diseases related to oxidation.

Quantification of isoflavone glycosides and aglycones in rat plasma by LC-MS/MS: Troubleshooting of interference from food and its application to pharmacokinetic study of Semen Sojae Praeparatum extract

The isoflavones widely exist in the daily diets and interferences are usually inevitable in the determination of the in vivo level of the same analytes. A new strategy to eliminate the dietary interference was established to evaluate the exposure of isoflavones including daidzin, glycitin, genistin, daidzein, glycitein, and genistein in rats fed with Semen Sojae Praeparatum (SSP) extract. Plasma samples were pretreated by liquid-liquid extraction with ethyl acetate using quercetin as the internal standard (IS). The chromatographic separation was achieved on a Symmetry C18 column (100 mm × 3.0 mm) using a gradient mobile phase consisting of acetonitril and water (containing 0.1% formic acid) with a run time of 13.0 min at a flow rate of 0.4ml/min. The detection was carried out by a triple-quadrupole tandem mass spectrometer in multiple reaction monitoring (MRM) mode via polarity switching between negative (for and positive (for daidzin glycitin) ionization mode. All calibration curves exhibited good linearity (r> 0.99) over a wide concentration range for all components. The lower limit of quantitation (LLOQ) was in the range of 0.1-0.4 ng/ml. The intra-day and inter-day precisions (RSD) at three different levels were both less than 14.9% and the accuracies (RE) ranged from -9.3% to 14.5%. The extraction recoveries of the analytes and the IS ranged from 85.7% to 100.2%. The validated method was first successfully applied to pharmacokinetic study of the six isoflavones in rat plasma after oral administration of SSP extract. The dynamic baseline levels of six isoflavones in blank plasma from rats consuming food containing dietary isoflavones were measured for the correction of the plasma concentrations. The principle pharmacokinetic parameters were calculated from rats with or without regular commercial food, and found to be altered by the dietary food containing some isoflavones.