The metabolism and analysis of isoflavones and other dietary polyphenols in foods and biological systems

Time maters: Exploring the dynamics of bioactive compounds content, bioaccessibility and antioxidant activity during Lupinus angustifolius germination

Germination is a process that enhances the content of health-promoting secondary metabolites. However, the bioaccessibility of these compounds depends on their stability and solubility throughout the gastrointestinal tract. The study aimed to explore how germination time influences the content and bioaccessibility of γ-aminobutyric acid and polyphenols and antioxidant capacity of lupin (Lupinus angustifolius L.) sprouts during simulated gastrointestinal digestion. Gamma-aminobutyric acid showed a decrease following gastrointestinal digestion (GID) whereas phenolic acids and flavonoids exhibited bioaccessibilities of up to 82.56 and 114.20%, respectively. Although the digestion process affected the profile of phenolic acids and flavonoids, certain isoflavonoids identified in 7-day sprouts (G7) showed resistance to GID. Germination not only favored antioxidant activity but also resulted in germinated samples exhibiting greater antioxidant properties than ungerminated counter parts after GID. Intestinal digests from G7 did not show cytotoxicity in RAW 264.7 macrophages, and notably, they showed an outstanding ability to inhibit the production of reactive oxygen species. This suggests potential benefit in mitigating oxidative stress. These findings contribute to understand the dynamic interplay between bioprocessing and digestion in modulating the bioaccessibility of bioactive compounds in lupin, thereby impacting health.

Unveiling the neuroprotective properties of isoflavones: current evidence, molecular mechanisms and future perspectives

Neurodegenerative diseases encompass a wide range of debilitating and incurable brain disorders characterized by the progressive deterioration of the nervous system's structure and function. Isoflavones, which are naturally occurring polyphenolic phytochemicals, have been found to regulate various cellular signaling pathways associated with the nervous system. The main objective of this comprehensive review is to explore the neuroprotective effects of isoflavones, elucidate the underlying mechanisms, and assess their potential for treating neurodegenerative disorders. Relevant data regarding isoflavones and their impact on neurodegenerative diseases were gathered from multiple library databases and electronic sources, including PubMed, Google Scholar, Web of Science, and Science Direct. Numerous isoflavones, including genistein, daidzein, biochanin A, and formononetin, have exhibited potent neuroprotective properties against various neurodegenerative diseases. These compounds have been found to modulate neurotransmitters, which in turn contributes to their ability to protect against neurodegeneration. Both in vitro and in vivo experimental studies have provided evidence of their neuroprotection mechanisms, which involve interactions with estrogenic receptors, antioxidant effects, anti-inflammatory properties, anti-apoptotic activity, and modulation of neural plasticity. This review aims to provide current insights into the neuroprotective characteristics of isoflavones and shed light on their potential therapeutic applications in future clinical scenarios.

The Mediterranean Diet, Its Microbiome Connections, and Cardiovascular Health: A Narrative Review

The Mediterranean diet (MD), rich in minimally processed plant foods and in monounsaturated fats but low in saturated fats, meat, and dairy products, represents one of the most studied diets for cardiovascular health. It has been shown, from both observational and randomized controlled trials, that MD reduces body weight, improves cardiovascular disease surrogates such as waist-to-hip ratios, lipids, and inflammation markers, and even prevents the development of fatal and nonfatal cardiovascular disease, diabetes, obesity, and other diseases. However, it is unclear whether it offers cardiovascular benefits from its individual components or as a whole. Furthermore, limitations in the methodology of studies and meta-analyses have raised some concerns over its potential cardiovascular benefits. MD is also associated with characteristic changes in the intestinal microbiota, mediated through its constituents. These include increased growth of species producing short-chain fatty acids, such as Clostridium leptum and Eubacterium rectale, increased growth of Bifidobacteria, Bacteroides, and Faecalibacterium prausnitzii species, and reduced growth of Firmicutes and Blautia species. Such changes are known to be favorably associated with inflammation, oxidative status, and overall metabolic health. This review will focus on the effects of MD on cardiovascular health through its action on gut microbiota.

Physiological functions of poorly absorbed polyphenols via the glucagon-like peptide-1

Polyphenols are compounds of plant origin with several documented bioactivities related to health promotion. Some polyphenols are hard to be absorbed into the body due to their structural characteristics. This review focuses on the health beneficial effects of polyphenols mediated by intestinal hormones, particularly related to the systemic functions through the secretion of glucagon-like peptide-1 (GLP-1), an enteric hormone that stimulates postprandial insulin secretion. GLP-1 is secreted from L cells in the distal small intestine. Therefore, some poorly absorbed polyphenols are known to have the ability to act on the intestines and promote GLP-1 secretion. It has been reported that it not only reduces hyperglycemia but also prevents obesity by reduction of overeating and improves blood vessel function. This review discusses examples of health effects of polyphenols mediated by GLP-1 secretion.

Influence of malting procedure on the isoflavonoid content of soybeans

The goal of this study was to analyse, whether malting technique (consisting of seed hydration, germination and drying) can be used to modify concentration of various isoflavonoids in soybean seeds. Seeds of three soybean varieties were germinated by different lengths of time (from 24 to 120 h) and dried by two different methods, typically used to produce so-called 'light' and 'caramel' malts. It was determined, that malting decreases concentration of 7-O-β-D-glucosides such as daidzin, genisitin and glycitin, while at the same time increasing concentration of aglycones (daidzein, genistein and glycitein). Increasing time of the germination period increased concentration of aglycones. 'Caramel' type malts were characterised with higher concentration of most of the isoflavonoids (daidzin, daidzein, genistin, genistein and glycitein) than 'light' type malts. Results of this study suggest that soybean malts can be an interesting substrate in the production of various food products with increased aglycone content.

Heat shock increases the anti-inflammatory and anti-obesity activity of soybean by increasing polyphenol, antioxidant and aglycon form isoflavones

We know that heat shock can activate the functional components in soybeans, but we don't know the type, level, and duration of heat shock for maximum activation. To address this, the present study investigated the changes in functional components like polyphenols, antioxidants, and isoflavones in soybeans at various temperature levels and durations with their respective functionality or health benefits. For this, treated seed samples were extracted with 70 % ethanol. Heat shock at 60 °C for 2 h increased polyphenol content (60.67 % of control) and antioxidant activity for both ABTS (41.14 % of control) and DPPH (217.72 % of control). This also increased the beneficial aglycone form of isoflavones that includes daidzein (8.36-fold of control), glycitein (3.85-fold of control) and genistein (20.50-fold of control) but decreased the harmful β-glucoside form (3.65-fold) including daiazin (1.84-fold of control); glycitin (1.45-fold of control) and genistin (23.88-fold of control) over untreated dry seed. This may happen because of the conversion of conjugated β-glucoside isoflavones to their aglycone forms that have various health benefits. Maximum inhibition of NO production in RAW 264.7 cells was achieved by samples elicited for 2 h with 300 μg/mL concentration. This sample also confirmed the maximum anti-obesity activity treated against 3-T-3L1 cells. This study summarized that heat shock at 60 °C for 2 h increased polyphenols, antioxidants, and aglycon isoflavone in soybeans resulting in increased anti-inflammatory and anti-obesity activity.

A Randomized, Placebo-Controlled Clinical Trial of a Novel Dietary Supplement (Braini) on Standardized CNS Vital Signs Cognitive Performance Parameters in Adults

Objective: To test the effectiveness of a novel dietary supplement as a support for cognitive function in healthy younger and older adults Design: A double-blind, randomized, placebo-controlled trial of the dietary supplement, Braini^® in two age cohorts with 60 participants: 31 healthy younger adults (18-30 years) and 29 healthy older adults (55-80 years). Intervention: A 28-day intervention of a dietary supplement (active or placebo) taken daily with cognitive assessment using CNS Vital Signs computer-based testing at day 0 and 28. Participants were asked to fill out a daily survey regarding compliance with supplement protocol, changes in health, adherence to the protocol, and reported side effects. CNS Vital Signs provides aged normed aggregated outcome measures for Processing Speed, Psychomotor Speed, Reaction Time, Cognitive Flexibility, Executive Function, and Motor Speed. Results: Significant improvements in performance were found for two CNS Vital Signs domains, Cognitive Flexibility (p = 0.048), and Executive Function (p = 0.025) in the treated younger adults (n = 12) compared with the placebo group (n = 19) at day 28 compared with baseline. The Shifting Attention Test Reaction Time (SAT-RT), a measure of shifting attention correct response reaction time, showed significant improvement at 28 days in those taking Braini in both younger (p = 0.004) and older adult cohorts (p = 0.05) with an average improvement over the control subjects of 44%. No serious side effects were reported. Conclusions: The dietary formulation, Braini, safely and significantly improved cognitive flexibility and executive function in younger adults and trended positively in older adults in this study that was stopped prematurely due to pandemic restrictions. Scores on SAT-RT significantly improved in both younger and older adults. Further studies are needed to confirm that Braini reliably improves cognitive function in additional CNS domains in healthy adults (Clinicaltrials.gov under registration number: NCT04025255).

Effects of fruits and vegetables on gut microbiota in a mouse model of metabolic syndrome induced by high-fat diet

The aim of this study was to evaluate the effect of fruit and vegetable intake on gut microbiota using a mouse model of metabolic syndrome (MS) induced by a high-fat diet. Forty-eight male mice were randomly divided into four groups, control group (C), high-fat diet-fed model group (H), high fat plus low intake of fruits and vegetables diet-fed group (H.LFV), high fat plus high intake of fruits and vegetables diet-fed group (H.HFV), and each group were fed for 60 days. During the experiment, mouse body weights were recorded and fecal samples were collected. Cetyltrimethyl ammonium bromide (CTAB) method was used to extract fecal bacterial DNA, and the purity and concentration of the DNA were detected by electrophoresis. DNA samples underwent PCR amplification (primers in 16 S V4 (515F and 806R)). Raw sequencing data were processed, and sample complexity and multiple-sample comparisons were investigated. Mouse organ coefficient, serum lipid levels, fecal TC (total cholesterol) and TBA (total bile acid) levels, and hepatic glutathione and malondialdehyde levels were determined. Compared to the H group, the fecal TC and TBA levels decreased significantly in the H.HFV group (p < .05), and hepatic glutathione and malondialdehyde levels decreased significantly in both H.LFV and H.HFV groups (p < .05). Decreased abundance of Firmicutes, Burkholderiales, Syntrophomonas, and Pseudomonadales in gut microbiota was observed in H.LFV and H.HFV groups compared to the H group. The Anosim results showed significant differences in pairwise comparison between groups. The linear discriminant analysis effect size (LEfSe) results showed that k_bacteria not only exhibited statistically differences between H and C groups but also among H.LFV, H.LFV, and H groups, and hence, could be used as a biomarker between groups. To sum up, fruit and vegetable powder could increase the fecal excretion of TC and TBA, and the antioxidant capacity in C57BL/6N mice. Meanwhile, the mechanism that fruit and vegetable powder could prevent MS in C57BL/6N mice was related to the decreased abundance of gut microbiota, including Firmicutes, Syntrophomonadales, and Pseudomonadales. Hence, fruit and vegetable powder could be used as a recommended food to regulate gut microbiota and prevent the occurrence of MS-related diseases.

Ameliorating Effect of the Edible Mushroom Hericium erinaceus on Depressive-Like Behavior in Ovariectomized Rats

Estrogen deficiency during menopause causes a variety of neurological symptoms, including depression. The edible Lion's Mane mushroom, Hericium erinaceus (Bull.: Fr.) Pers. (HE), is a medicinal mushroom that has the potential for a neuroprotective effect and ameliorating neurological diseases, such as depression, anxiety, and neurodegenerative diseases. HE contains phytoestrogens, including daidzein and genistein. However, the ameliorating effect of HE on menopausal symptoms is not well understood. Here we investigated the impact of methanol extract of the HE fruiting body on depressive-like behavior in postmenopausal model rats. The activation of estrogen receptor alpha (ERα) causes body weight loss and uterine weight gain. Body weight gain and uterine weight loss by estrogen deficiency in ovariectomized (OVX) rats were reversed with 17β-estradiol (E₂) but not with HE. Thus, the phytoestrogens in HE may hardly activate ERα. Estrogen receptor beta (ERβ) is expressed in the brain, and activation of ERβ ameliorates menopausal depressive symptoms. Notably, depressive-like behavior in OVX rats evaluated in forced swim test was reduced by administration of not only E₂ but also HE for 92 d. Long-term activation of ERα increases the risk of breast and uterine cancers. HE, therefore, may be effective in treating menopausal depression without the risk of carcinogenesis caused by ERα activation.

Bioactive Flavonoids: A Comprehensive Review on Pharmacokinetics and Analytical Aspects

Flavonoids are a diversified group of natural substances which were discovered to provide a variety of health benefits in human beings. Vegetables, fruits, wine and tea are the primary flavonoid dietary sources for humans and as the flavonoids are so closely connected to human dietary items and health, it is vital to explore the structural-activity connection. The arrangement, replacement of functional groups, and total number of hydroxyl groups around flavonoid's nucleus structure affect their biological activity, metabolism, and bioavailability. Various flavonoids have been proven to have hepatoprotective properties, that help in the prevention of coronary heart disease. Similarly, these flavonoids also possess anticancer, and anti-inflammatory activities. Flavonoids have been found to have a functional and structural link with their enzyme inhibitory action, that appears to have antiviral effect through acting as antioxidants, damaging cell membranes, blocking enzymes, activating mechanisms of host self-defense, and limiting virus penetration and attaching to cells. Identification, characterization, isolation, and biological role of flavonoids, as well as their uses on health advantages, are all major topics in research and development currently. This review represents a summary of various sources of flavonoids, class, subclass, their chemical structures, biological activities, the pharmacokinetics of flavonoids and various analytical, bioanalytical and electrochemical methods for determination of flavonoids from different matrices.

Advances on Cyclocarya paliurus polyphenols: Extraction, structures, bioactivities and future perspectives

Cyclocaryapaliurus (C. paliurus) is an edible and medicinal plant, distributed in southern China. As a kind of new food raw material, the leaves of C. paliurus are processed as tea products in daily life. C. paliurus is recognized as a good source to polyphenols, showing excellent bioactivities, which has attracted more and more attention. Polyphenols are important functional bioactive components in C. paliurus. C. paliurus polyphenols perform nutritional functions in anti-diabetes, anti-hyperlipidemic, anti-obesity, anti-oxidant, and other activities. In this review, we summarize the research progress of extraction technologies, structural characteristics, and bioactivities of C. paliurus polyphenols. Other potential functions of C. paliurus polyphenols are prospected. This review provides a reference for further research and applications of C. paliurus polyphenols in a field of functional food and medicines.

Neuroprotective Effects of Quercetin on Ischemic Stroke: A Literature Review

Ischemic stroke (IS) is characterized by high recurrence and disability; however, its therapies are very limited. As one of the effective methods of treating acute attacks of IS, intravenous thrombolysis has a clear time window. Quercetin, a flavonoid widely found in vegetables and fruits, inhibits immune cells from secreting inflammatory cytokines, thereby reducing platelet aggregation and limiting inflammatory thrombosis. In pre-clinical studies, it has been shown to exhibit neuroprotective effects in patients with ischemic brain injury. However, its specific mechanism of action remains unknown. Therefore, this review aims to use published data to elucidate the potential value of quercetin in patients with ischemic brain injury. This article also reviews the plant sources, pharmacological effects, and metabolic processes of quercetin in vivo, thus focusing on its mechanism in inhibiting immune cell activation and inflammatory thrombosis as well as promoting neuroprotection against ischemic brain injury.

Focusing on Formononetin: Recent Perspectives for its Neuroprotective Potentials

Nervous system is the most complex system of the human body, hence, the neurological diseases often lack effective treatment strategies. Natural products have the potential to yield unique molecules and produce integrative and synergic effects compared to standard therapy. Mounting evidence has shown that isoflavonoids contained in traditional medicinal plant or dietary supplementation may play a crucial role in the prevention and treatment of neurological diseases due to their pronounced biological activities correlating to nervous system. Formononetin, a non-steroidal isoflavonoid, is a bioactive constituent of numerous medicinal plants such as red clover (Trifolium pratense) and Astragalus membranaceus. Emerging evidence has shown that formononetin possesses considerable anti-inflammatory, antioxidant and anti-cancer effects. This review intends to analyze the neuropharmacological potential of formononetin on the therapy of nervous system disorders. The neuroprotective properties of formononetin are observed in multiple neurological disorders including Alzheimer’s disease, dementia, cerebral ischemia, traumatic brain injury, anxiety, and depression. The beneficial effects of formononetin are achieved partially through attenuating neuroinflammation and oxidative stress via the related signaling pathway. Despite its evident effects in numerous preclinical studies, the definite role of formononetin on humans is still less known. More well-designed clinical trials are required to further confirm the neuroprotective efficacy and safety profile of formononetin before its application in clinic.

Polyphenol Extracts From Germinated Mung Beans Can Improve Type 2 Diabetes in Mice by Regulating Intestinal Microflora and Inhibiting Inflammation

Studies have shown that inhibiting inflammation and regulating intestinal microflora imbalance is a significant factor in controlling the development of type 2 diabetes mellitus (T2DM). This experiment studied the protective effect of polyphenol extract from germinated mung beans on diabetic C57BL/6 mice.

Results

Fasting blood glucose (FBG) was decreased, glucose tolerance was increased, insulin resistance was decreased, serum lipid indexes in T2DM mice were improved, and the enzyme activities of alanine aminotransferase (ALT) and aspartate transaminase (AST) in serum were reduced. Meanwhile, the levels of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) in serum were decreased, the concentration of interleukin 10 (IL-10) in serum was increased, inhibiting the inflammatory reaction induced by diabetes and repairing the morphology of mice liver tissue. At the same time, germinated mung bean polyphenol (GMP) can regulate the main intestinal flora, Firmicutes, Bacteroidetes, and Proteobacteria in diabetic mice and can also regulate species diversity and improve intestinal flora imbalance. Taken together, the experimental conclusion is a certain dose of polyphenol extract from germinated mung beans that can improve mouse T2DM by inhibiting inflammatory reaction and regulating intestinal microflora.

Antioxidant and Cytotoxic Activities of Kudzu Roots and Soy Molasses against Pediatric Tumors and Phytochemical Analysis of Isoflavones Using HPLC-DAD-ESI-HRMS

Pediatric solid tumors (PSTs) are life-threatening and can lead to high morbidity and mortality rates in children. Developing novel remedies to treat these tumors, such as glioblastoma multiforme and sarcomas, such as osteosarcoma, and rhabdomyosarcoma, is challenging, despite immense attempts with chemotherapeutic or radiotherapeutic interventions. Soy (Glycine max) and kudzu roots (KR) (Pueraria spp.) are well-known phytoestrogenic botanical sources that contain high amounts of naturally occurring isoflavones. In the present study, we investigated the antioxidant and cytotoxic effects of the extracts of KR and soy molasses (SM) against PSTs. The green extraction of isoflavones from KR and SM was performed using natural deep eutectic solvents. The extracts were subsequently analyzed by high-performance liquid chromatography (HPLC)-diode array detector (DAD) coupled with high-resolution (HR) mass spectrometry (MS), which identified 10 isoflavones in KR extracts and 3 isoflavones in the SM extracts. Antioxidant and cytotoxic activities of KR and SM extracts were assessed against glioblastoma multiforme (A-172), osteosarcoma (HOS), and rhabdomyosarcoma (Rd) cancer cell lines. The KR and SM extracts showed satisfactory cytotoxic effects (IC₅₀) against the cancer cell lines tested, particularly against Rd cancer cell lines, in a dose-dependent manner. Antioxidant activity was found to be significantly (p ≤ 0.05) higher in KR than in SM, which was consistent with the results of the cytotoxic activity observed with KR and SM extracts against glioblastoma and osteosarcoma cells. The total flavonoid content and antioxidant activities of the extracts were remarkably attributed to the isoflavone content in the KR and SM extracts. This study provides experimental evidence that HPLC-ESI-HRMS is a suitable analytical approach to identify isoflavones that exhibit potent antioxidant and anticancer potential against tumor cells, and that KR and SM, containing many isoflavones, can be a potential alternative for health care in the food and pharmaceutical industries.

Multiomics analysis of soybean meal induced marine fish enteritis in juvenile pearl gentian grouper, Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂

As an important protein source, soybean products can cause intestinal inflammation and injury in many animals including human beings, particularly infants and juvenile individuals. Research in this field has been performed for terrestrial animals and fish, but still lacks integrity and systematicness. In this study, the main biological processes in the intestinal tract of marine fish juvenile pearl gentian grouper in the state of soybean meal-induced enteritis (SBMIE) were analyzed. A total of 720 groupers with an approximate initial weight of 12.5 g were randomly divided into three groups: the fish meal (FM) control group, the 20% SBM group (SBM20), and the SBM40 group (n = 4). Three iso-nitrogenous and iso-lipidic diets were prepared and fed to fish for 10 weeks. Each barrel contained a water volume of about 1 m3 in and was exposed to natural light and temperature. Results indicated that the growth and physiology of groupers fed with SBM were significantly negatively affected, with the gene expressions of intestinal structural protein abnormal. 16SrDNA high-throughput sequencing showed that the intestinal microflora played an important role in the pathogenesis of pearl gentian grouper SBMIE, which may activate a variety of pathogen pattern recognition receptors, such as toll-like receptors (TLRs), RIG-I-like receptors, and nod-like receptors. Transcriptome analysis revealed that changes of the SBMIE signaling pathway in pearl gentian groupers were conservative to some extent than that of terrestrial animals and freshwater fish. Moreover, the TLRs-nuclear factor kappa-B signaling pathway becomes activated, which played an important role in SBMIE. Meanwhile, the signal pathways related to nutrient absorption and metabolism were generally inhibited. Metabolomics analysis showed that isoflavones and saponins accounted for a large proportion in the potential biomarkers of pearl gentian grouper SBMIE, and most of the biomarkers had significantly positive or negative correlations with each other; 56 metabolites were exchanged between intestinal tissues and contents, which may play an important role in the development of enteritis, including unsaturated fatty acids, organic acids, amino acids, vitamins, small peptides, and nucleotides, etc. These results provide a basic theoretical reference for solving the intestinal issues of fish SBMIE and research of inflammatory bowel disease in mammals.

Nanotechnology-Based Drug Delivery Strategies to Repair the Mitochondrial Function in Neuroinflammatory and Neurodegenerative Diseases

Mitochondria are vital organelles in eukaryotic cells that control diverse physiological processes related to energy production, calcium homeostasis, the generation of reactive oxygen species, and cell death. Several studies have demonstrated that structural and functional mitochondrial disturbances are involved in the development of different neuroinflammatory (NI) and neurodegenerative (ND) diseases (NI&NDDs) such as multiple sclerosis, Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Remarkably, counteracting mitochondrial impairment by genetic or pharmacologic treatment ameliorates neurodegeneration and clinical disability in animal models of these diseases. Therefore, the development of nanosystems enabling the sustained and selective delivery of mitochondria-targeted drugs is a novel and effective strategy to tackle NI&NDDs. In this review, we outline the impact of mitochondrial dysfunction associated with unbalanced mitochondrial dynamics, altered mitophagy, oxidative stress, energy deficit, and proteinopathies in NI&NDDs. In addition, we review different strategies for selective mitochondria-specific ligand targeting and discuss novel nanomaterials, nanozymes, and drug-loaded nanosystems developed to repair mitochondrial function and their therapeutic benefits protecting against oxidative stress, restoring cell energy production, preventing cell death, inhibiting protein aggregates, and improving motor and cognitive disability in cellular and animal models of different NI&NDDs.

Dietary Phytoestrogens and Their Metabolites as Epigenetic Modulators with Impact on Human Health

The impact of dietary phytoestrogens on human health has been a topic of continuous debate since their discovery. Nowadays, based on their presumptive beneficial effects, the amount of phytoestrogens consumed in the daily diet has increased considerably worldwide. Thus, there is a growing need for scientific data regarding their mode of action in the human body. Recently, new insights of phytoestrogens’ bioavailability and metabolism have demonstrated an inter-and intra-population heterogeneity of final metabolites’ production. In addition, the phytoestrogens may have the ability to modulate epigenetic mechanisms that control gene expression. This review highlights the complexity and particularity of the metabolism of each class of phytoestrogens, pointing out the diversity of their bioactive gut metabolites. Futhermore, it presents emerging scientific data which suggest that, among well-known genistein and resveratrol, other phytoestrogens and their gut metabolites can act as epigenetic modulators with a possible impact on human health. The interconnection of dietary phytoestrogens’ consumption with gut microbiota composition, epigenome and related preventive mechanisms is discussed. The current challenges and future perspectives in designing relevant research directions to explore the potential health benefits of dietary phytoestrogens are also explored.

The Effects of Soy Products on Cardiovascular Risk Factors in Patients with Type 2 Diabetes: A Systematic Review and Meta-analysis of Clinical Trials

Previous studies have suggested that soy products may be beneficial for cardiometabolic health, but current evidence regarding their effects in type 2 diabetes mellitus (T2DM) remain unclear. The aim of this systematic review and meta-analysis was to determine the impact of soy product consumption on cardiovascular risk factors in patients with T2DM. PubMed, Scopus, Embase, and the Cochrane library were systematically searched from inception to March 2021 using relevant keywords. All randomized controlled trials (RCTs) investigating the effects of soy product consumption on cardiovascular risk factors in patients with T2DM were included. Meta-analysis was performed using random-effects models and subgroup analysis was performed to explore variations by dose and baseline risk profile. A total of 22 trials with 867 participants were included in this meta-analysis. Soy product consumption led to a significant reduction in serum concentrations of triglycerides (TG) (WMD: -24.73 mg/dL; 95% CI: -37.49, -11.97), total cholesterol (TC) (WMD: -9.84 mg/dL; 95% CI: -15.07, -4.61), low density lipoprotein (LDL) cholesterol (WMD: -6.94 mg/dL; 95% CI: -11.71, -2.17) and C-reactive protein (CRP) (WMD: -1.27 mg/L; 95% CI: -2.39, -0.16). In contrast, soy products had no effect on high density lipoprotein (HDL) cholesterol, fasting blood sugar (FBS), fasting insulin, hemoglobin A1c (HbA1c), homeostatic model assessment of insulin resistance (HOMA-IR), systolic and diastolic blood pressure (SBP/DBP) or body mass index (BMI) (all P ≥ 0.05). In subgroup analyses, there was a significant reduction in FBS after soy consumption in patients with elevated baseline FBS (>126 mg/dL) and in those who received higher doses of soy intake (>30 g/d). Moreover, soy products decreased SBP in patients with baseline hypertension (>135 mmHg). Our meta-analysis suggests that soy product consumption may improve cardiovascular parameters in patients with T2DM, particularly in individuals with poor baseline risk profiles. However, larger studies with longer durations and improved methodological quality are needed before firm conclusions can be reached.

3-(3-Hydroxyphenyl)propionic acid, a microbial metabolite of quercetin, inhibits monocyte binding to endothelial cells via modulating E-selectin expression

Adhesion of monocytes to endothelial cells is an important initiating step in atherogenesis. One of the most abundant flavonoids in the diet, quercetin has been reported to inhibit monocyte adhesion to endothelial cells. However, it is poorly absorbed in the upper gastrointestinal tract during oral intake but rather is metabolized by the intestinal microbiota into various phenolic acids. Since the biological properties of the microbial metabolites of quercetin remain largely unknown, herein, we investigated how the microbial metabolite of quercetin, 3-(3-hydroxyphenyl)propionic acid (3HPPA) impact monocyte adhesion to endothelial cells. Direct treatment with 3HPPA for 24 h was not cytotoxic to human aortic endothelial cells (HAECs). Cotreatment with 3HPPA inhibited tumor necrosis factor α (TNFα)-induced adhesion of THP-1 monocytes to HAECs, and suppressed the upregulation of cell adhesion molecule E-selectin but not intercellular adhesion molecule 1 or vascular cell adhesion molecule 1. Furthermore, 3HPPA was found to inhibit TNFα-induced nuclear translocation and phosphorylation of the p65 subunit of nuclear factor κB (NF-κB). We conclude that 3HPPA mitigates the adhesion of monocytes to endothelial cells by suppressing the expression of the cell adhesion molecule E-selectin in HAECs via inhibition of the NF-κB pathway, providing additional evidence for the health benefits of dietary flavonoids and their microbial metabolites as therapeutic agents in atherosclerosis.

Effects of isoflavone derivatives on the production of inflammatory cytokines by synovial cells

The present study investigated the effects of isoflavone derivatives (daidzein, genistein and glycitein) on the production of inflammatory cytokines (IL-6 and IL-8) by IL-1β-stimulated synovial cells. Synovial MH7A cells were stimulated with IL-1β in the absence or presence of isoflavone derivatives, and IL-6 and IL-8 production was measured by ELISA. The results of the present study indicated that daidzein significantly inhibited the production of IL-6, but not IL-8. Conversely, neither genistein nor glycitein exerted any inhibitory effects on the production of IL-6 or IL-8 by IL-1β-stimulated synovial cells. To elucidate the molecular mechanisms underlying the daidzein-mediated inhibition of IL-6 production, the present study examined the effects of daidzein on the phosphorylation (activation) of NF-κB p65, ERK1/2 and p38 MAPK. Daidzein significantly inhibited the phosphorylation of NF-κB p65 and ERK1/2, but not p38 MAPK in IL-1β-stimulated MH7A cells. The present study revealed that among the isoflavone derivatives examined (daidzein, genistein and glycitein), daidzein inhibited the production of IL-6, but not IL-8, by IL-1β-stimulated synovial MH7A cells via the suppression of NF-κB p65 and ERK1/2 activation. Collectively, these results suggested that daidzein may have potential as a therapeutic agent for the treatment of arthritic disorders through its anti-inflammatory effects via the inhibition of IL-6 production.

Oestrogenic metabolite equol negatively impacts the functionality of ram spermatozoa in vitro

Oestrogenic pastures are known to cause infertility in the ewe, due primarily to the oestrogen-like actions of the metabolite equol. Despite strong evidence that phytoestrogens and their metabolites compromise male reproductive function in many other species, there is little information concerning the effect of oestrogenic pastures on ram sperm quality and function. To investigate this, ram spermatozoa were exposed in vitro to physiologically relevant concentrations of either 0, 0.001, 0.01, 0.1 and 1 μM equol and incubated over 6 h. Sperm motility, viability, DNA integrity, membrane lipid disorder, mitochondrial superoxide production, lipid peroxidation and intracellular reactive oxygen species were assessed via computer assisted sperm analysis and flow cytometry at 0.5, 3 and 6 h post-equol exposure. Whilst sperm viability was decreased only at 1 μM equol at 0.5 h post-exposure, exposure to equol at concentrations of 0.1 and 1 μM reduced sperm total and progressive motility (P < 0.001), increased sperm membrane fluidity (P < 0.001), increased mitochondrial superoxide production (P < 0.001) and promoted lipid peroxidation (P < 0.001) across all timepoints. At 6 h post-exposure to 0.1 and 1 μM equol, DNA fragmentation was greater compared that of non-exposed spermatozoa (P = 0.045). Intracellular reactive oxygen species did not change between treatment groups throughout the study (P > 0.05). It is concluded that even low concentrations of equol negatively impact the functionality of ram spermatozoa, these effects likely driven through increased mitochondrial superoxide production. This work indicates that equol may exert oestrogen-like actions upon ram spermatozoa, bringing into question as to whether oestrogenic pastures could influence ram fertility.

Olive Polyphenols: Antioxidant and Anti-Inflammatory Properties

Oxidative stress and inflammation triggered by increased oxidative stress are the cause of many chronic diseases. The lack of anti-inflammatory drugs without side-effects has stimulated the search for new active substances. Plant-derived compounds provide new potential anti-inflammatory and antioxidant molecules. Natural products are structurally optimized by evolution to serve particular biological functions, including the regulation of endogenous defense mechanisms and interaction with other organisms. This property explains their relevance for infectious diseases and cancer. Recently, among the various natural substances, polyphenols from extra virgin olive oil (EVOO), an important element of the Mediterranean diet, have aroused growing interest. Extensive studies have shown the potent therapeutic effects of these bioactive molecules against a series of chronic diseases, such as cardiovascular diseases, diabetes, neurodegenerative disorders and cancer. This review begins from the chemical structure, abundance and bioavailability of the main EVOO polyphenols to highlight the effects and the possible molecular mechanism(s) of action of these compounds against inflammation and oxidation, in vitro and in vivo. In addition, the mechanisms of inhibition of molecular signaling pathways activated by oxidative stress by EVOO polyphenols are discussed, together with their possible roles in inflammation-mediated chronic disorders, also taking into account meta-analysis of population studies and clinical trials.

Mechanistic insights and perspectives involved in neuroprotective action of quercetin

Neurodegenerative diseases (NDDs) are the primary cause of disabilities in the elderly people. Growing evidence indicates that oxidative stress, mitochondrial dysfunction, neuroinflammation and apoptosis are associated with aging and the basis of most neurodegenerative disorders. Quercetin is a flavonoid with significant pharmacological effects and promising therapeutic potential. It is widely distributed among plants and typically found in daily diets mainly in fruits and vegetables. It shows a number of biological properties connected to its antioxidant activity. Neuroprotection by quercetin has been reported in many in vitro as well as in in vivo studies. However, the exact mechanism of action is still mystery and similarly there are a number of hypothesis exploring the mechanism of neuroprotection. Quercetin enhances neuronal longevity and neurogenesis by modulating and inhibiting wide number of pathways. This review assesses the food sources of quercetin, its pharmacokinetic profile, structure activity relationship and its pathophysiological role in various NDDs and it also provides a synopsis of the literature exploring the relationship between quercetin and various downstream signalling pathways modulated by quercetin for neuroprotection for eg. nuclear factor erythroid 2-related factor 2 (Nrf2), Paraoxonase-2 (PON2), c-Jun N-terminal kinase (JNK), Tumour Necrosis Factor alpha (TNF-α), Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha (PGC-1α), Sirtuins, Mitogen-activated protein kinases (MAPKs) signalling cascades, CREB (Cyclic AMP response element binding protein) and Phosphoinositide 3- kinase(PI3K/Akt). Therefore, the aim of the present review was to elaborate on the cellular and molecular mechanisms of the quercetin involved in the protection against NDDs.

Preparation of cerium-curcumin and cerium-quercetin complexes and their LEDs irradiation assisted anticancer effects on MDA-MB-231 and A375 cancer cell lines

Cancer remains common and often is difficult to eradicate. In particular resistant forms like triple negative breast cancer and melanoma generally allow for very short survival. Curcumin and quercetin as two important polyphenols from plants which have different biological roles, potentially including anti-cancer effect. But their clinical application is limited due to poor solubility in aqueous medium. Photodynamic therapy (PDT) is a cancer treatment using select chemical compounds as photosensitizers, which when activated by light create toxic singlet oxygen. Studies done on plant based photosensitizers such as curcumin and quercetin have shown the ability to ablate tumors. Here we discuss using them as improved PS by making their complex with cerium ions as a delivery system for MDA-MB-231 and A375 cancer cell lines treatment. For this purpose, the MDA-MB-231 human breast cancer cell line exposed to red light irradiation (as pretreatment) then treated with curcumin and quercetin alone and also their complex with cerium. In another study the cells treated with curcumin-cerium and quercetin-cerium complex and then irradiated with blue light (photodynamic treatment). Cell survival and apoptosis were determined using MTT and fluorescence microscopy. The result showed that curcumin and quercetin in complex with cerium ions have better toxic effect against both breast and melanoma cancer cells as compared to each compound alone. The finding revealed that curcumin and quercetin in cerium complex could be considered as a new approach in the photodynamic treatment of breast and melanoma cancer cells.

Morin as an imminent functional food ingredient: an update on its enhanced efficacy in the treatment and prevention of metabolic syndromes

Flavonoids represent polyphenolic plant secondary metabolites with a general structure of a 15-carbon skeleton comprising two phenyl rings and a heterocyclic ring. Over 5000 natural flavonoids (flavanones, flavanonols, and flavans) from various plants have been characterized. Several studies provide novel and promising insights into morin hydrate for its different biological activities against a series of metabolic syndromes. The present review is a rendition of its sources, chemistry, functional potency, and protective effects on metabolic syndromes ranging from cancer to brain injury. Most importantly this systematic review article also highlights the mechanisms of interest to morin-mediated management of metabolic disorders. The key mechanisms (anti-oxidative and anti-inflammatory) responsible for its therapeutic potential are well featured after collating the in vitro and in vivo study reports. As a whole, based on the prevailing information rationalizing its medicinal use, morin can be identified as a therapeutic agent for the expansion of human health.

The Influence of Plant Isoflavones Daidzein and Equol on Female Reproductive Processes

In this review, we explore the current literature on the influence of the plant isoflavone daidzein and its metabolite equol on animal and human physiological processes, with an emphasis on female reproduction including ovarian functions (the ovarian cycle; follicullo- and oogenesis), fundamental ovarian-cell functions (viability, proliferation, and apoptosis), the pituitary and ovarian endocrine regulators of these functions, and the possible intracellular mechanisms of daidzein action. Furthermore, we discuss the applicability of daidzein for the control of animal and human female reproductive processes, and how to make this application more efficient. The existing literature demonstrates the influence of daidzein and its metabolite equol on various nonreproductive and reproductive processes and their disorders. Daidzein and equol can both up- and downregulate the ovarian reception of gonadotropins, healthy and cancerous ovarian-cell proliferation, apoptosis, viability, ovarian growth, follicullo- and oogenesis, and follicular atresia. These effects could be mediated by daidzein and equol on hormone production and reception, reactive oxygen species, and intracellular regulators of proliferation and apoptosis. Both the stimulatory and the inhibitory effects of daidzein and equol could be useful for reproductive stimulation, the prevention and mitigation of cancer development, and the adverse effects of environmental stressors in reproductive biology and medicine.

Plant Polyphenols as Neuroprotective Agents in Parkinson's Disease Targeting Oxidative Stress

Parkinson's disease (PD) is the second most prevalent progressive neurodegenerative disorder characterized by the degeneration of dopaminergic neurons in the human midbrain. Various ongoing research studies are competing to understand the pathology of PD and elucidate the mechanisms underlying neurodegeneration. Current pharmacological treatments primarily focused on improving dopamine metabolism in PD patients, despite the side effects of long-term usage. In recent years, it is recognized that oxidative stress-mediated pathways lead to neurodegeneration in the brain, which is associated with the pathophysiology of PD. The importance of oxidative stress is often less emphasized when developing potential therapeutic approaches. Natural plant antioxidants have been shown to mediate the oxidative stress-induced effects in PD, which has gained considerable attention in both in vitro and in vivo studies. Yet, clinical trials on natural polyphenol compounds are limited, restricting the potential use of these compounds as an alternative treatment for PD. Therefore, this review provides an understanding of the oxidative stress-induced effects in PD by elucidating the underlying events contributing to oxidative stress and explore the potential use of polyphenols in improving the oxidative status in PD. Preclinical findings have supported the potential of polyphenols in providing neuroprotection against oxidative stress-induced toxicity in PD. However, limiting factors, such as safety and bioavailability of polyphenols, warrant further investigations so as to make them the potential target for clinical applications in the treatment and management of PD.

The Emerging Role of Polyphenols in the Management of Type 2 Diabetes

Type 2 diabetes (T2D) is a fast-increasing health problem globally, and it results from insulin resistance and pancreatic β-cell dysfunction. The gastrointestinal (GI) tract is recognized as one of the major regulatory organs of glucose homeostasis that involves multiple gut hormones and microbiota. Notably, the incretin hormone glucagon-like peptide-1 (GLP-1) secreted from enteroendocrine L-cells plays a pivotal role in maintaining glucose homeostasis via eliciting pleiotropic effects, which are largely mediated via its receptor. Thus, targeting the GLP-1 signaling system is a highly attractive therapeutic strategy to treatment T2D. Polyphenols, the secondary metabolites from plants, have drawn considerable attention because of their numerous health benefits, including potential anti-diabetic effects. Although the major targets and locations for the polyphenolic compounds to exert the anti-diabetic action are still unclear, the first organ that is exposed to these compounds is the GI tract in which polyphenols could modulate enzymes and hormones. Indeed, emerging evidence has shown that polyphenols can stimulate GLP-1 secretion, indicating that these natural compounds might exert metabolic action at least partially mediated by GLP-1. This review provides an overview of nutritional regulation of GLP-1 secretion and summarizes recent studies on the roles of polyphenols in GLP-1 secretion and degradation as it relates to metabolic homeostasis. In addition, the effects of polyphenols on microbiota and microbial metabolites that could indirectly modulate GLP-1 secretion are also discussed.

Enzymatic pretreatment in the extraction process of soybean to improve protein and isoflavone recovery and to favor aglycone formation

This research aimed to evaluate the pretreatment of soybean with the carbohydrase multi-enzyme complex "Viscozyme L", during the extraction process; in order to improve the recovery of proteins and isoflavones in soybase, and reduce the loss of these compounds through the okara residue. Three concentrations of enzyme were studied at 50 °C, along with an experiment carried out without enzyme addition (control experiment). The results were also evaluated in relation to standard soybase processing. In comparison to the standard and control processes, the enzymatic pretreatment reduced up to 85% the total amount of okara residue. Due to the action of the multi-enzyme complex, protein and total isoflavone recovery increased from 42% to 83% and from 59% to 93%, respectively. The application of Viscozyme L also favored the conversion of conjugated forms of isoflavone to aglycone in the soybase, representing up to 50% of the total isoflavones. The enzymatic pretreatment of soybean with carbohydrase improved the nutritional quality of the soybase, while at the same time reducing residue generation; showing that the proposed food process can be considered environmentally friendly method.

Fermentation of Danggui Buxue Tang, an ancient Chinese herbal mixture, together with Lactobacillus plantarum enhances the anti-diabetic functions of herbal product

Background

Danggui Buxue Tang (DBT), an ancient Chinese herbal decoction containing Astragali Radix and Angelicae Sinensis Radix at a ratio of 5: 1, is prescribed for menopausal women. Flavonoids and its flavonoid glycosides are considered as the major active ingredients within the herbal decoction; however, their amount is not controllable during the preparation. Besides, the aglycons within DBT are believed to have better gut absorption and pharmacological efficacy.

Methods

The herbal extract of DBT was fermented with Lactobacillus plantarum. The amounts of flavonoid glucosides and its aglycones in the fermented product were analyzed by using UPLC-MS/MS. In addition, in vitro assays were employed to evaluate the efficacy of the fermented DBT in regulating the activities of α-glucosidase, α-amylase and lipase, as well as their antioxidant capacity (DPPH and T-AOC assays) and anti-glycation property (BSA-methylglyoxal, BSA-fructose, and arginine-methylglyoxal models).

Results

The fermentation of DBT with L. plantarum drove a completed conversion of calycosin-7-O-β-D-glucoside and ononin to calycosin and formononetin, respectively. The chemical transformation could be probably mediated by β-glycosidase within the fermented product. Several in vitro assays corresponding to anti-diabetic functions were compared between parental DBT against its fermented product, which included the activities against α-glucosidase, α-amylase and lipase, as well as anti-oxidation and anti-glycation. The fermented DBT showed increased activities in inhibiting α-glycosidase, suppressing DPPH radical-scavenging and anti-glycation, as compared to the original herbal product.

Conclusion

These results suggested that DBT being fermented with the probiotic L. plantarum could pave a new direction for fermentation of herbal extract, as to strengthen its pharmacological properties in providing health benefits.

Plant natural products with anti-thyroid cancer activity

Thyroid cancer is the most frequent endocrine malignancy, with more than 500,000 cases per year worldwide. Differentiated thyroid cancers are the most common forms with best prognosis, while poorly/undifferentiated ones are rare (2% of all thyroid cancer), aggressive, frequently metastasize and have a worse prognosis. For aggressive, metastatic and advanced thyroid cancer novel antitumor molecules are urgently needed and phytochemical products can be a rational and extensive source, since secondary plant metabolites can guarantee the necessary biochemical variability for therapeutic purpose. Among bioactive molecules that present biological activity on thyroid cancer, resveratrol, curcumin, isoflavones, glucosinolates are the most common and used in experimental model. Most of them have been studied both in vitro and in vivo on this cancer, but rarely in clinical trial. This review summarizes phytochemicals, phytotherapeutics and plant derived compounds used in thyroid cancer.

Feeding brown fat: dietary phytochemicals targeting non-shivering thermogenesis to control body weight

Excessive adipose accumulation, which is the main driver for the development of secondary metabolic complications, has reached epidemic proportions and combined pharmaceutical, educational and nutritional approaches are required to reverse the current rise in global obesity prevalence rates. Brown adipose tissue (BAT) is a unique organ able to dissipate energy and thus a promising target to enhance BMR to counteract a positive energy balance. In addition, active BAT might support body weight maintenance after weight loss to prevent/reduce relapse. Natural products deliver valuable bioactive compounds that have historically helped to alleviate disease symptoms. Interest in recent years has focused on identifying nutritional constituents that are able to induce BAT activity and thereby enhance energy expenditure. This review provides a summary of selected dietary phytochemicals, including isoflavones, catechins, stilbenes, the flavonoids quercetin, luteolin and resveratrol as well as the alkaloids berberine and capsaicin. Most of the discussed phytochemicals act through distinct molecular pathways e.g. sympathetic nerve activation, AMP-kinase signalling, SIRT1 activity or stimulation of oestrogen receptors. Thus, it might be possible to utilise this multitude of pathways to co-activate BAT using a fine-tuned combination of foods or combined nutritional supplements.

The Microbiome-Estrogen Connection and Breast Cancer Risk

The microbiome is undoubtedly the second genome of the human body and has diverse roles in health and disease. However, translational progress is limited due to the vastness of the microbiome, which accounts for over 3.3 million genes, whose functions are still unclear. Numerous studies in the past decade have demonstrated how microbiome impacts various organ-specific cancers by altering the energy balance of the body, increasing adiposity, synthesizing genotoxins and small signaling molecules, and priming and regulating immune response and metabolism of indigestible dietary components, xenobiotics, and pharmaceuticals. In relation to breast cancer, one of the most prominent roles of the human microbiome is the regulation of steroid hormone metabolism since endogenous estrogens are the most important risk factor in breast cancer development especially in postmenopausal women. Intestinal microbes encode enzymes capable of deconjugating conjugated estrogen metabolites marked for excretion, pushing them back into the enterohepatic circulation in a biologically active form. In addition, the intestinal microbes also break down otherwise indigestible dietary polyphenols to synthesize estrogen-like compounds or estrogen mimics that exhibit varied estrogenic potency. The present account discusses the potential role of gastrointestinal microbiome in breast cancer development by mediating metabolism of steroid hormones and synthesis of biologically active estrogen mimics.

Combinatorial Epigenetics Impact of Polyphenols and Phytochemicals in Cancer Prevention and Therapy

Polyphenols are potent micronutrients that can be found in large quantities in various food sources and spices. These compounds, also known as phenolics due to their phenolic structure, play a vital nutrient-based role in the prevention of various diseases such as diabetes, cardiovascular diseases, neurodegenerative diseases, liver disease, and cancers. However, the function of polyphenols in disease prevention and therapy depends on their dietary consumption and biological properties. According to American Cancer Society statistics, there will be an expected rise of 23.6 million new cancer cases by 2030. Due to the severity of the increased risk, it is important to evaluate various preventive measures associated with cancer. Relatively recently, numerous studies have indicated that various dietary polyphenols and phytochemicals possess properties of modifying epigenetic mechanisms that modulate gene expression resulting in regulation of cancer. These polyphenols and phytochemicals, when administrated in a dose-dependent and combinatorial-based manner, can have an enhanced effect on epigenetic changes, which play a crucial role in cancer prevention and therapy. Hence, this review will focus on the mechanisms of combined polyphenols and phytochemicals that can impact various epigenetic modifications such as DNA methylation and histone modifications as well as regulation of non-coding miRNAs expression for treatment and prevention of various types of cancer.

Hypouricemic and nephroprotective roles of anthocyanins in hyperuricemic mice

Hyperuricemia (HUA) is a universal metabolic disorder characterized by a high level of uric acid in the serum. Anthocyanins (ACNs) are a group of natural flavonoids that have shown favourable bioactivities in the metabolic syndrome but the effect on uric acid metabolism remains underexplored. The present study investigated the hypouricemic effects of ACNs in a mice model and further studied the potential mechanisms. ICR mice based on a high-yeast diet were administered potassium oxonate (PO, 280 mg per kg body weight) and inosine (400 mg per kg body weight) to induce a hyperuricemia model, meanwhile, ACNs were supplemented by gavage. The mice were sacrificed after 3 weeks of treatment. ACN administration significantly reduced serum uric acid (SUA), blood urea nitrogen (BUN) and serum creatinine (Scr) levels and suppressed xanthine oxidase (XOD) activity in mice serum and liver. In addition, ACNs down-regulated the expression of hepatic XOD, caspase-1, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) and regulated the expression of renal urate transporters URAT1, GLUT9, ABCG2, OAT1, OAT3, OCT1, OCT2, OCTN1 and OCTN2. According to histological analysis, ACN treatment exhibited hepatoprotective and nephroprotective effects in hyperuricemic mice. In conclusion, ACNs reduced urate production and promoted uric acid excretion from the renal system, which suggests the potential of ACNs for the future treatment of HUA.

A newly isolated human intestinal bacterium strain capable of deglycosylating flavone C-glycosides and its functional properties

Background

Flavone C-glycosides are difficult to be deglycosylated using traditional chemical methods due to their solid carbon–carbon bond between sugar moieties and aglycones; however, some bacteria may easily cleave this bond because they generate various specific enzymes.

Results

A bacterial strain, named W12-1, capable of deglycosylating orientin, vitexin, and isovitexin to their aglycones, was isolated from human intestinal bacteria in this study and identified as Enterococcus faecalis based on morphological examination, physiological and biochemical identification, and 16S rDNA sequencing. The strain was shown to preferentially deglycosylate the flavone C-glycosides on condition that the culture medium was short of carbon nutrition sources such as glucose and starch, and its deglycosylation efficiency was negatively correlated with the content of the latter two substances.

Conclusion

This study provided a new bacterial resource for the cleavage of C-glycosidic bond of flavone C-glycosides and reported the carbon nutrition sources reduction induced deglycosylation for the first time.

Electronic supplementary material

The online version of this article (10.1186/s12934-019-1144-7) contains supplementary material, which is available to authorized users.

Rapid Identification of Kudzu Powder of Different Origins Using Laser-Induced Breakdown Spectroscopy

The rapid identification of kudzu powder of different origins is of great significance for studying the authenticity identification of Chinese medicine. The feasibility of rapidly identifying kudzu powder origin was investigated based on laser-induced breakdown spectroscopy (LIBS) technology combined with chemometrics methods. The discriminant models based on the full spectrum include extreme learning machine (ELM), soft independent modeling of class analogy (SIMCA), K-nearest neighbor (KNN) and random forest (RF), and the accuracy of models was more than 99.00%. The prediction results of KNN and RF models were best: the accuracy of calibration and prediction sets of kudzu powder from different producing areas both reached 100%. The characteristic wavelengths were selected using principal component analysis (PCA) loadings. The accuracy of calibration set and the prediction set of discrimination models, based on characteristic wavelengths, is all higher than 98.00%. Random forest and KNN have the same excellent identification results, and the accuracy of calibration and prediction sets of kudzu powder from different producing areas reached 100%. Compared with the full spectrum discriminant analysis model, the discriminant analysis model based on the characteristic wavelength had almost the same discriminant effects, and the input variables were reduced by 99.92%. The results of this research show that the characteristic wavelength can be used instead of the LIBS full spectrum to quickly identify kudzu powder from different producing areas, which had the advantages of reducing input, simplifying the model, increasing the speed and improving the model effect. Therefore, LIBS technology is an effective method for rapid identification of kudzu powder from different habitats. This study provides a basis for LIBS to be applied in the genuineness and authenticity identification of Chinese medicine.

Enantiomeric Isoflavones with neuroprotective activities from the Fruits of Maclura tricuspidata

Seven pairs of enantiomeric isoflavones (1a/1b–7a/7b) were obtained from the ethyl acetate extract of the fruits of Maclura tricuspidata (syn. Cudrania tricuspidata), and successfully separated by chiral high-pressure liquid chromatography (HPLC). The structures and absolute configurations of the enantiomeric isoflavones were established on the basic of comprehensive spectroscopic analyses and quantum chemical calculation methods. Compounds 1, 1a, and 1b exhibited neuroprotective activities against oxygen-glucose deprivation/reoxygenation (ODG/R)-induced SH-SY5Y cells death with EC₅₀ values of 5.5 µM, 4.0 µM, and 10.0 µM, respectively. Furthermore, 1, 1a, and 1b inhibited OGD/R-induced reactive oxygen species generation in SH-5Y5Y cells with IC₅₀ values of 6.9 µM, 4.5 µM, and 9.5 µM, respectively.

Biological evaluation of isoflavonoids from Genista halacsyi using estrogen-target cells: Activities of glucosides compared to aglycones

The purpose of this study was to evaluate the response of estrogen target cells to a series of isoflavone glucosides and aglycones from Genista halacsyi Heldr. The methanolic extract of aerial parts of this plant was processed using fast centrifugal partition chromatography, resulting in isolation of four archetypal isoflavones (genistein, daidzein, isoprunetin, 8-C-β-D-glucopyranosyl-genistein) and ten derivatives thereof. 7-O-β-D-glucopyranosyl-genistein and 7,4΄-di-O-β-D-glucopyranosyl-genistein were among the most abundant constituents of the isolate. All fourteen, except genistein, displayed low binding affinity for estrogen receptors (ER). Models of binding to ERα could account for the low binding affinity of monoglucosides. Genistein and its glucosides displayed full efficacy in inducing alkaline phosphatase (AlkP) in Ishikawa cells, proliferation of MCF-7 cells and ER-dependent gene expression in reporter cells at low concentrations (around 0.3 μM). ICI182,780 fully antagonized these effects. The AlkP-inducing efficacy of the fourteen isoflavonoids was more strongly correlated with their transcriptional efficacy through ERα. O-monoglucosides displayed higher area under the dose-response curve (AUC) of AlkP response relative to the AUC of ERα-transcriptional response compared to the respective aglycones. In addition, 7-O-β-D-glucopyranosyl-genistein and 7,4΄-di-O-β-D-glucopyranosyl-genistein displayed estradiol-like efficacy in promoting differentiation of MC3T3-E1 cells to osteoblasts, while genistein was not convincingly effective in this respect. Moreover, 7,4΄-di-O-β-D-glucopyranosyl-genistein suppressed lipopolysaccharide-induced tumor necrosis factor mRNA expression in RAW 264.7 cells, while 7-O-β-D-glucopyranosyl-genistein was not convincingly effective and genistein was ineffective. However, genistein and its O-glucosides were ineffective in inhibiting differentiation of RAW 264.7 cells to osteoclasts and in protecting glutamate-challenged HT22 hippocampal neurons from oxidative stress-induced cell death. These findings suggest that 7-O-β-D-glucopyranosyl-genistein and 7,4΄-di-O-β-D-glucopyranosyl-genistein display higher estrogen-like and/or anti-inflammatory activity compared to the aglycone. The possibility of using preparations rich in O-β-D-glucopyranosides of genistein to substitute for low-dose estrogen in formulations for menopausal symptoms is discussed.

Differential ability of formononetin to stimulate proliferation of endothelial cells and breast cancer cells via a feedback loop involving MicroRNA-375, RASD1, and ERα

For postmenopausal cardiovascular disease, long-term estrogen therapy may increase the risk of breast cancer. To reduce this risk, estrogen may be replaced with the phytoestrogen formononetin, but how formononetin acts on vascular endothelial cells (ECs) and breast cancer cells is unclear. Here, we show that low concentrations of formononetin induced proliferation and inhibited apoptosis more strongly in cultured human umbilical vein endothelial cells (HUVECs) than in breast cancer cells expressing estrogen receptor α (ERα) (MCF-7, BT474) or not (MDA-MB-231), and that this differential stimulation was associated with miR-375 up-regulation in HUVECs. For the first time, we demonstrate the presence of a feedback loop involving miR-375, ras dexamethasone-induced 1 (RASD1), and ERα in normal HUVECs, and we show that formononetin stimulated this feedback loop in HUVECs but not in MCF-7 or BT474 cells. In all three cell lines, formononetin increased Akt phosphorylation and Bcl-2 expression. Inhibiting miR-375 blocked these changes and increased proliferation in HUVECs, but not in MCF-7 or BT474 cells. In ovariectomized rats, formononetin increased uterine weight and caused similar changes in levels of miR-375, RASD1, ERα, and Bcl-2 in aortic ECs as in cultured HUVECs. In mice bearing MCF-7 xenografts, tumor growth was stimulated by 17β-estradiol but not by formononetin. These results suggest selective action of formononetin in ECs (proliferation stimulation and apoptosis inhibition) relative to breast cancer cells, possibly via a feedback loop involving miR-375, RASD1, and ERα. This differential effect may explain why formononetin may not increase the risk of postmenopausal breast cancer.