MATE-Type Proteins Are Responsible for Isoflavone Transportation and Accumulation in Soybean Seeds.

Soybeans are nutritionally important as human food and animal feed. Apart from the macronutrients such as proteins and oils, soybeans are also high in health-beneficial secondary metabolites and are uniquely enriched in isoflavones among food crops. Isoflavone biosynthesis has been relatively well characterized, but the mechanism of their transportation in soybean cells is largely unknown. Using the yeast model, we showed that GmMATE1 and GmMATE2 promoted the accumulation of isoflavones, mainly in the aglycone forms. Using the tobacco BrightYellow-2 (BY-2) cell model, GmMATE1 and GmMATE2 were found to be localized in the vacuolar membrane. Such subcellular localization supports the notion that GmMATE1 and GmMATE2 function by compartmentalizing isoflavones in the vacuole. Expression analyses showed that GmMATE1 was mainly expressed in the developing soybean pod. Soybean mutants defective in GmMATE1 had significantly reduced total seed isoflavone contents, whereas the overexpression of GmMATE1 in transgenic soybean promoted the accumulation of seed isoflavones. Our results showed that GmMATE1, and possibly also GmMATE2, are bona fide isoflavone transporters that promote the accumulation of isoflavones in soybean seeds.

In sacco evaluation of ruminal degradability of isoflavones from full-fat soybean and extracted soybean meal-A pilot study.

The aim of the study was to determine the ruminal degradability of dry matter (DM), daidzein, genistein, glycitein and total isoflavones in ground full-fat soybean (GFFS) and solvent-extracted soybean meal (SSBM) using the in sacco method. The experiment was carried out in three replications on ruminally cannulated sheep that were fed twice a day with a diet consisted of hay and supplemental mixture (6:4, DM basis). The nylon bags with 2 g feed samples ground to 2 mm were incubated in the rumen for 0, 2, 4, 8, 16 and 24 h. The effective degradability (ED) of DM, daidzein, genistein, glycitein and total isoflavones was calculated at outflow rate of 0.06 h. The ED of DM in GFFS was 77.8% and was higher than in SSBM being 71.8% (p < 0.001). The ED of daidzein (96.8%) and genistein (93.6%) was higher for SSBM compared with GFFS (93.9% and 92.8%, p < 0.001 and p = 0.003, respectively) while ED of glycitein was lower for SSBM than for GFFS (75.5 and 81.7%, respectively, p < 0.001). All isoflavones in the incubations were extensively degraded in the rumen, and regardless of dietary source, they were almost completely degraded after 16 h of incubation. Further, the disappearance patterns, that is the functions describing the time courses of the analyte disappearance, were assessed. The disappearance patterns of daidzein, genistein, glycitein and total isoflavones were similar and showed greater disappearance of mentioned isoflavones from SSBM compared to GFFS (p < 0.001 for daidzein, genistein and total isoflavones and p = 0.002 for glycitein). The study provides knowledge on the effect of processing on degradability of isoflavones in rumen that can be used to clarify the interrelationship between isoflavones and rumen microbiota.

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.

Glycitein induces reactive oxygen species-dependent apoptosis and G0/G1 cell cycle arrest through the MAPK/STAT3/NF-κB pathway in human gastric cancer cells.

Glycitein is an isoflavone that reportedly inhibits the proliferation of human breast cancer and prostate cancer cells. However, its anti-cancer molecular mechanisms in human gastric cancer remain to be defined. This study evaluated the antitumor effects of glycitein on human gastric cancer cells and investigated the underlying mechanisms. We used MTT assay, flow cytometry and western blotting to investigate its molecular mechanisms with focus on reactive oxygen species (ROS) production. Our results showed that glycitein had significant cytotoxic effects on human gastric cancer cells. Glycitein markedly decreased mitochondrial transmembrane potential (ΔΨm) and increased AGS cells mitochondrial-related apoptosis, and caused G0/G1 cell cycle arrest by regulating cycle-related protein. Mechanistically, accompanying ROS, glycitein can activate mitogen-activated protein kinase (MAPK) and inhibited the signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappaB (NF-κB) signaling pathways. Furthermore, the MAPK signaling pathway regulated the expression levels of STAT3 and NF-κB upon treatment with MAPK inhibitor and N-acetyl-L-cysteine (NAC). These findings suggested that glycitein induced AGS cell apoptosis and G0/G1 phase cell cycle arrest via ROS-related MAPK/STAT3/NF-κB signaling pathways. Thus, glycitein has the potential to a novel targeted therapeutic agent for human gastric cancer.

Isoflavones.

Phytoestrogens are naturally occurring nonsteroidal phenolic plant compounds that, due to their molecular structure and size, resemble vertebrate steroids estrogens. This review is focused on plant flavonoids isoflavones, which are ranked among the most estrogenic compounds. The main dietary sources of isoflavones for humans are soybean and soybean products, which contain mainly daidzein and genistein. When they are consumed, they exert estrogenic and/or antiestrogenic effects. Isoflavones are considered chemoprotective and can be used as an alternative therapy for a wide range of hormonal disorders, including several cancer types, namely breast cancer and prostate cancer, cardiovascular diseases, osteoporosis, or menopausal symptoms. On the other hand, isoflavones may also be considered endocrine disruptors with possible negative influences on the state of health in a certain part of the population or on the environment. This review deals with isoflavone classification, structure, and occurrence, with their metabolism, biological, and health effects in humans and animals, and with their utilization and potential risks.

Anti-Influenza Virus Activity of Adlay Tea Components.

Our previous study showed anti-influenza virus activity in adlay tea prepared from adlay seeds, naked barley seeds, soybean, and cassia seeds. In this study, we evaluated the anti-influenza virus activity of each component of this tea and analyzed their active ingredients. Each component was roasted and extracted in hot water; the extracts were tested for antiviral activity and their mechanisms of action were studied. All the tea components showed antiviral activity against the H1N1 and H3N2 influenza subtypes and against influenza B. The viral stages inhibited by the components were virus adsorption and replication in proliferative process, suggesting that the action mechanisms of the components might differ from those of oseltamivir acid. Of the tea components, soybean showed the strongest activity. Therefore, we analyzed its active ingredients by liquid chromatography quadruple time-of-flight mass spectrometry (LC/qTOF-MS) and daidzein and glycitein were detected as active ingredients. Here, anti-influenza virus action of glycitein was the first report.

Glycitein prevents reserpine-induced depression and associated comorbidities in mice: modulation of lipid peroxidation and TNF-α levels.

Depression is a debilitating mood disorder affecting millions worldwide and continues to pose a significant global health burden. Due to the multifaceted nature of depression, the current treatment regimens are not up to mark in terms of their multitargeting potential and least side effect profile. Molecules within the isoflavone class demonstrate promising potential in alleviating depression and associated conditions, offering a multifaceted approach to manage mental health concerns. Therefore, the current study was designed to explore the potential of glycitein, an isoflavone in managing reserpine-induced depression and associated comorbidities in mice. Reserpine (0.5 mg/kg; i.p.) administration for the first 3 days induced depression and associated comorbidities as evidenced by increased immobility time in forced swim test (FST) and tail suspension test (TST), along with reduced locomotor activity in the open field test (OFT) and increased latency to reach the platform in the Morris water maze (MWM) test. Reserpine treatment also upregulated and downregulated the brain thiobarbituric acid reactive substance (TBARS) and glutathione (GSH) levels, respectively. Furthermore, reserpine administration also uplifted the level of TNF-α in the serum samples. Glycitein (3 mg/kg and 6 mg/kg; p.o.) treatment for 5 days prevented the depressive effect of reserpine. It also improved the spatial memory at both dose levels. Moreover, in biochemical analysis, glycitein also reduced the brain TBARS and serum tumor necrosis factor-alpha (TNF-α) levels. Whereas, no significant effect was seen on the brain GSH level. Glycitein (6 mg/kg) was found to be more effective than the 3 mg/kg dose of glycitein. Overall results delineate that glycitein has the potential to manage depression and impaired memory by inhibiting lipid peroxidation and inflammatory stress.

Effect of Genistein and Glycitein on production performance, egg quality, antioxidant function, reproductive hormones and related-genes in pre-peak laying hens.

Genistein (GEN) and Glycitein (GLY), are types of isoflavone extracted mainly from soy plants, although GEN is associated with stronger antioxidant and growth-promoting effects. The impact of dietary GEN and GLY on reproductive performance, egg quality, and bone quality were investigated in the study. Additionally, to explore the underlying mechanism of action, the serum hormone levels and reproductive-related genes were investigated. A total of 378 Hy-Line Brown laying hens (120 days old) were randomly allocated to 3 dietary groups (Control), (GLY, and GEN at 50 mg/kg respectively) for a period of 8 wk. Each treatment has 126 birds (7 replicates of 18 birds each). Results were analyzed in 2 phases: wk 1 to 4, and 5 to 8 of feeding trial. The results indicated that supplemental GEN significantly increased egg number, hen-day production (HDP), and egg mass during wk 1 to 4, whereas, both glycitein and genistein increased egg number, egg weight, egg mass, HDP and improved feed-egg-ratio during wk 5 to 8. Egg quality analysis revealed significant improvements in eggshell quality; gloss, thickness, strength, and albumen quality indices (albumen height, Haugh unit, thick albumen fraction) due to dietary treatments. Also, the tibia strength, Ca content in the tibia ash and bone mineral content, were significantly increased by the dietary treatments. Significant increases in the serum levels of E2, LH, FSH, T3, T4, and GH, and the activity of antioxidant enzymes; SOD, CAT, GSH while reducing the level of MDA, was notable with the treatments. Additionally, reproductive-related genes: ESR1, FSHR, PRLR, GNRH1 were significantly upregulated by the supplementation of GEN and GLY. The efficacy of GEN in relation to the evaluated parameters was superior to that of GLY. Conclusively, we speculate that the improvement on laying performance, egg quality and tibia quality may be related to promoting effect of isoflavones on calcium metabolism, antioxidant function, reproductive hormones and related genes. Therefore, supplemental GEN at a dosage level of 50 mg/kg, can be used to promote laying performance, sustain egg production and maintain the physiological function of young laying hens.

Identification of Genes Responsible for the Synthesis of Glycitein Isoflavones in Soybean Seeds.

Soybean (Glycine max (L.) Merrill) isoflavones are among the most important secondary metabolites, with functional benefits for human health. Soybeans accumulate three aglycone forms of isoflavones: genistein, daidzein, and glycitein. Soybean landrace Kumachi-1 does not accumulate malonylglycitin at all. Gene structure analysis indicated that Glyma.11G108300 (F6H4) of Kumachi-1 has a 3.8-kbp insertion, resulting in a truncated flavonoid 6-hydroxylase (F6H) sequence compared to the wild-type sequence in Fukuyutaka. Mapping experiments using a mutant line (MUT1246) with a phenotype similar to that of Kumachi-1, with a single-nucleotide polymorphism (SNP) in F6H4, revealed co-segregation of this mutation and the absence of glycitein isoflavones. We also identified a mutant line (K01) that exhibited a change in the HPLC retention time of glycitein isoflavones, accumulating glycoside and malonylglycoside forms of 6-hydroxydaidzein. K01 contains an SNP that produces a premature stop codon in Glyma.01G004200 (IOMT3), a novel soybean isoflavone O-methyltransferase (IOMT) gene. We further analyzed transgenic hairy roots of soybeans expressing Glyma.11G108300 (F6H4) and Glyma.01G004200 (IOMT3). Those overexpressing F6H4 accumulated malonylglycoside forms of 6-hydroxydaidzein (M_6HD), and co-expression of F6H4 and IOMT3 increased the level of malonylglycitin but not of M_6HD. These results indicate that F6H4 and IOMT3 are responsible for glycitein biosynthesis in soybean seed hypocotyl.

Soy-derived isoflavones as chemo-preventive agents targeting multiple signalling pathways for cancer prevention and therapy.

The chemopreventive and chemotherapeutic properties of soy and soy-derived compounds, especially isoflavones, have been extensively studied in recent years. However, in contrast to their anticancer effects, such as cell growth inhibition, cell cycle arrest and apoptosis induction, isoflavones have also been found to promote the growth of cancer cells. Therefore, the aim of this comprehensive review article is to present the current state of knowledge regarding the molecular mechanisms by which soy-derived isoflavones target multiple cellular signalling pathways in cancer cells. Our findings indicate that soy-derived isoflavones act as, among other things, potent modulators of HOX transcript antisense RNA (HOTAIR)/SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1), vascular endothelial growth factor (VEGF)/C-X-C motif chemokine ligand 12 (CXCL12)/C-X-C motif chemokine receptor type 4 (CXCR4), 17-ß-oestradiol (E2)/oestrogen receptor-α (ERα)/neuroglobin (NGB) and sonic hedgehog signalling pathways, epigenetic modulatory agents (i.a. miR-155, miR-34a and miR-10a-5p) and cancer stem cells and epithelial-to-mesenchymal transition inhibitors. The paper also discusses the latest epidemiological studies and clinical trials and provides an insight into recent extensive research on the chemo-preventive and therapeutic potential of soy-derived isoflavones.

Cytochrome GmGLY1 is Involved in the Biosynthesis of Glycitein in Soybean.

Isoflavones, the major secondary metabolites of interest due to their benefits to both human and plant health, are exclusively produced by legumes. In this study, we profiled the isoflavone content in dry seeds from 211 soybean [Glycine max (L.) Merr.] accessions grown across five environments. Broad and discernible phenotypic variations were observed among accessions, regions, and years of growth. Twenty-six single-nucleotide polymorphisms (SNPs) associated with the sum of glycitein (GLE), glycitin (GL), 6″-O-acetylglycitin (AGL), and 6″-O-malonylglycitin (MGL) contents were detected in multiple environments via a genome-wide association study (GWAS). These SNPs were located on chromosome 11 (8,148,438 bp to 8,296,956 bp, renamed qGly11-01). Glyma.11g108300 (GmGLY1), a gene that encodes a P450 family protein, was identified via sequence variation analysis, functional annotation, weighted gene coexpression network analysis (WGCNA), and expression profile analysis of candidate gene, and hairy roots transformation in soybean. Overexpression of GmGLY1 increased the glycitein content (GLC) in soybean hairy roots and transgenic seeds, while CRISPR/Cas9-generated mutants exhibited decreased GLC and increased daidzein content (DAC). Haplotype analysis revealed that GmGLY1 allelic variations significantly affect the GLC accumulation. These findings enhance our understanding of genes influencing GLC in soybean and may guide breeding for lines with high and stable GLC.

Transformation profiles of the isoflavones in germinated soybean based on UPLC-DAD quantification and LC-QTOF-MS/MS confirmation.

Germinated soybean is one kind of food and a medicine. In the actual process of producing a large amount of naturally germinated soybean, it is difficult to strictly control the germination process conditions. However, sprout length may be more suitable as the terminal judgment indicator for naturally germinated soybean. An UPLC-DAD method was developed and validated to explore the transformation profiles of soybean isoflavones in germinated yellow or black soybean with different sprout lengths. Moreover, an LC - QTOF-MS/MS method was used to avoid false positive results. The contents of daidzein, glycitein, and genistein almost reached their corresponding maximum values when the sprout length ranged from 1.0 cm to 1.5 cm (P < 0.05). Therefore, yellow soybean is suggested to be the processing raw material with higher contents of those isoflavones, and the optimal sprout length for germinated soybean may be in the range of 1.0-1.5 cm.

Inverse association between isoflavones and prediabetes risk: evidence from NHANES 2007-2010 and 2017-2018.

Introduction: Prediabetes is a metabolic condition characterized by blood glucose levels that are higher than normal but do not meet the threshold for a diabetes diagnosis. Individuals with prediabetes are at an increased risk of developing type 2 diabetes and associated complications. However, limited epidemiological studies have investigated the association between flavonoids from plant-based diets and the risk of prediabetes, and the existing evidence from these studies is inconsistent. Methods: Therefore, we utilized data from 19,021 participants (mean age: 32.03 years) in the National Health and Nutrition Examination Survey (NHANES) conducted during 2007-2010 and 2017-2018 to investigate the potential association between dietary flavonoid intake and prediabetes risk by weighted logistic regression analysis. Furthermore, the data from 3,706 participants (mean age: 35.98 years) from NHANES 2007-2010 were used to assess the correlation between concentrations of isoflavones and their metabolites in urine and prediabetes risk by weighted logistic regression analysis. Results: Our findings revealed an inverse association between the intake of glycitein (OR: 0.88; 95% CI: 0.82-0.96; p = 0.003), genistein (OR: 0.98; 95% CI: 0.97-0.99; p = 0.004), daidzein (OR: 0.98; 95% CI: 0.96-0.99; p = 0.009), and total isoflavones (OR: 0.99; 95% CI: 0.98-1.00; p = 0.005) with the risk of prediabetes. Moreover, we observed an inverse association between the concentration of daidzein in urine (OR: 0.84; 95% CI: 0.73-0.96; p = 0.012) and the concentration of genistein in urine (OR:0.83; 95% CI: 0.75-0.93; p = 0.003) with the risk of prediabetes using weighted logistic regression. Conclusion: In conclusion, our findings suggest a potential protective effect of isoflavones against the development of prediabetes.

Comparative investigation on variations of nutritional components in whole seeds and seed coats of Korean black soybeans for different crop years and screening of their antioxidant and anti-aging properties.

This research was conducted to demonstrate the comparisons of nutritional constituents (isoflavone; anthocyanin; protein; fatty acid; oil) and biological properties (antioxidant, anti-aging) in whole seeds and seed coats of black soybeans for crop years. Isoflavones and anthocyanins showed considerable differences in cultivars and growth years with the ranges of 794.9-4195.3 µg/g and 2.3-14.4 mg/g, while other components exhibited slight variations. In particular, malonylgenistin and cyanidin-3-O-glucoside were observed the most abundant phenolics, comprising approximately 35.5 (778.0 µg/g) and 76.7% (4.6 mg/g) of total average contents (isoflavone: 2197.8 µg/g; anthocyanin: 6.0 mg/g). Moreover, the whole seeds and seed coats displayed excellent activities in antioxidant (radical; DNA protectant), tyrosinase inhibition, and elastase inhibition. Their effects significantly occurred with dose-dependent patterns as follows: elastase (150 µg/mL) > tyrosinase (600 µg/mL) > ABTS (1500 µg/mL) > DPPH (1500 µg/mL) with higher abilities of seed coats than whole seeds. The DNA protection exhibited higher rates in seed coats with > 90% at 200 µg/mL. Natably, Socheong (isoflavone; 4182.4 µg/g) and Geomjeong 2 (anthocyanin: 10.3 mg/g) cultivars may be recommended as potential sources to the development of functional agents and new cultivars owing to their high average phenolic contents.

The Soybean High Density 'Forrest' by 'Williams 82' SNP-Based Genetic Linkage Map Identifies QTL and Candidate Genes for Seed Isoflavone Content.

Isoflavones are secondary metabolites that are abundant in soybean and other legume seeds providing health and nutrition benefits for both humans and animals. The objectives of this study were to construct a single nucleotide polymorphism (SNP)-based genetic linkage map using the 'Forrest' by 'Williams 82' (F×W82) recombinant inbred line (RIL) population (n = 306); map quantitative trait loci (QTL) for seed daidzein, genistein, glycitein, and total isoflavone contents in two environments over two years (NC-2018 and IL-2020); identify candidate genes for seed isoflavone. The FXW82 SNP-based map was composed of 2075 SNPs and covered 4029.9 cM. A total of 27 QTL that control various seed isoflavone traits have been identified and mapped on chromosomes (Chrs.) 2, 4, 5, 6, 10, 12, 15, 19, and 20 in both NC-2018 (13 QTL) and IL-2020 (14 QTL). The six QTL regions on Chrs. 2, 4, 5, 12, 15, and 19 are novel regions while the other 21 QTL have been identified by other studies using different biparental mapping populations or genome-wide association studies (GWAS). A total of 130 candidate genes involved in isoflavone biosynthetic pathways have been identified on all 20 Chrs. And among them 16 have been identified and located within or close to the QTL identified in this study. Moreover, transcripts from four genes (Glyma.10G058200, Glyma.06G143000, Glyma.06G137100, and Glyma.06G137300) were highly abundant in Forrest and Williams 82 seeds. The identified QTL and four candidate genes will be useful in breeding programs to develop soybean cultivars with high beneficial isoflavone contents.

Isoflavones in Animals: Metabolism and Effects in Livestock and Occurrence in Feed.

Soybeans are a common ingredient of animal feed. They contain isoflavones, which are known to act as phytoestrogens in animals. Isoflavones were described to have beneficial effects on farm animals. However, there are also reports of negative outcomes after the consumption of isoflavones. This review summarizes the current knowledge of metabolization of isoflavones (including the influence of the microbiome, phase I and phase II metabolism), as well as the distribution of isoflavones and their metabolites in tissues. Furthermore, published studies on effects of isoflavones in livestock species (pigs, poultry, ruminants, fish) are reviewed. Moreover, published studies on occurrence of isoflavones in feed materials and co-occurrence with zearalenone are presented and are supplemented with our own survey data.

Enhancement of isoflavone aglycone, amino acid, and CLA contents in fermented soybean yogurts using different strains: Screening of antioxidant and digestive enzyme inhibition properties.

This study was the first to evaluate changes in isoflavone, amino acid, conjugated linoleic acid (CLA), antioxidant effect, and digestive enzyme inhibition during fermentation of soy-milk to soy-yogurt with L. brevis and L. plantarum. Total average isoflavones were reduced (1318.2 â†’ 971.1 µg/g) with an increase of aglycones (60.2 â†’ 804.9 µg/g, genistein > daidzein > glycitein) in soy powder yogurts (SPYs). Amino acids increased considerably, as did ornithine (average 4.1 â†’ 551.0 mg/g), and CLA showed high variations from not-detected (ND) to 0.5, 0.9 mg/g (cis-9, trans-11) and ND to 0.3, 0.2 mg/g (trans-10, cis-12). Digestive enzyme inhibitions (α-glucosidase, α-amylase, and pancreatic lipase) displayed high activities (average 50.6 â†’ 67.2, 5.2 â†’ 46.4, 10.6 â†’ 51.4%). Moreover, the antioxidant abilities against radicals were elevated as follows: ABTS > DPPH > hydroxyl (average 63.5 â†’ 86.5, 50.2 â†’ 70.3, 39.3 â†’ 55.2%). Specifically, SPY using mixed strains exhibited the greatest enzymatic inhibition and antioxidant capacities.

Comparative analysis of isoflavone aglycones using microwave-assisted acid hydrolysis from soybean organs at different growth times and screening for their digestive enzyme inhibition and antioxidant properties.

The objectives of this research were to demonstrate the changes in isoflavone-aglycones, total phenolics, and biological properties (digestive enzyme inhibition; antioxidant) from six organs including leaves, leafstalks, roots, stems, seeds, and pods at different growth times of soybean plant. Three isoflavone-aglycones in microwave-assisted acid hydrolysis extracts were elucidated using UHPLC-ESI-Q-TOF-MS/MS and their contents exhibited remarkable differences in leaves (245.93-2239.33 µg/g), roots (854.96-4425.34 µg/g), and seeds (ND-2339.62 µg/g). Specifically, the collected samples on 15-Oct (leaves: 2239.33; seeds: 2339.62 µg/g) and 31-Aug (roots: 4425.34 µg/g) showed the highest isoflavone-aglycones, and daidzein was observed the most abundant component, comprising approximately 70%. Moreover, the inhibitions against α-glucosidase and α-amylase displayed the predominant effects in roots (89;91%) and leaves (81;85%) of samples on 31-Aug and 15-Oct at 300 µg/ml. The antioxidant activities on ABTS, DPPH, and hydroxyl radicals increased considerably with the increases of growth times in leaves and seeds, especially, ABTS showed the highest scavenging abilities: leaves (15-Oct;83%) > roots (31-Aug;75%) > seeds (15-Oct;68%). Therefore, our results suggest that soybean leaves, roots and seeds may be considered as excellent natural sources for nutraceuticals.

Isolation of individual isoflavone species from soybean by solvent extraction followed by the combination of macroporous resin and aluminium oxide separation.

Growing interest in the health benefits of soy isoflavones has led to research in the isolation of individual isoflavone species for further application. Herein, we develop a new strategy to isolate daidzein, genistein, daidzin and genistin in soybean. We investigated the impact of solvents used and the extraction time on the extracted isoflavone contents from soybean. A 30-min extraction with 65% aqueous methanol gave a total isoflavone yield of 345 mg/100 g soybean, the highest value among tested conditions. Further, we proposed a two-stage adsorption/desorption chromatography comprising macroporous resin and aluminium oxide to isolate isoflavone. First, HP-20 resin was used to separate the glucosidic and aglyconic forms of isoflavone, then individual species of isoflavone could be isolated using aluminium oxide by specific retention of 5-hydroxy isoflavone. This process achieved overall high recovery (82-97%) and purity (92-95%) of the four isoflavones, which confirms a high separating efficiency for isoflavones from soybean.

Androgen receptor and soy isoflavones in prostate cancer.

Androgens and androgen receptor (AR) play a critical role not only in normal prostate development, but also in prostate cancer. For that reason, androgen deprivation therapy (ADT) is the primary treatment for prostate cancer. However, the majority of patients develop castration-resistant prostate cancer, which eventually leads to mortality. Novel therapeutic approaches, including dietary changes, have been explored. Soy isoflavones have become a focus of interest because of their positive health benefits on numerous diseases, particularly hormone-related cancers, including prostate and breast cancers. An important strategy for the prevention and/or treatment of prostate cancer might thus be the action of soy isoflavones on the AR signaling pathway. The current review article provides a detailed overview of the anticancer potential of soy isoflavones (genistein, daidzein and glycitein), as mediated by their effect on AR.