Soybean Isoflavones Research Articles

DEHP-induced testicular injury through gene methylation pathway and the protective effect of soybean isoflavones in Sprague–Dawley rats

As one of the most important members of Phthalate esters (PAEs), di-(2-ethylhexyl) phthalate (DEHP) is widely used in plastics and known as a male reproductive toxicant. Many studies have shown that soybean isoflavones (SI) can rescue the testicular injury caused by DEHP, but the underlying mechanism is unknown. Because methylation is one of the most important mechanisms for maintaining normal biological functions, we studied whether methylation is involved in testicular injury induced by DEHP and whether SI could counter testicular impairment in peripubertal male Sprague Dawley rats. Compared with the control group, we found that the mRNA levels of testicular Sod2, Gpx1, and Igf-1 significantly decreased in the 900 mg/kg DEHP group (DEHP′ group) (P < 0.01); however, in the DEHP + SI group, the mRNA levels of the genes obviously increased compared with the DEHP’ group (P < 0.01). Simultaneously, the methylation level changes of testicular Sod2, Gpx1, and Igf-1 were similar to the mRNA levels (P < 0.01). Therefore, DEHP may affect testis and leydig cells via inducing methylation of Sod2, Gpx1, and Igf-1, and SI may rescue the impairments at the methylation level. In summary, SI is supposed to be used in DEHP-induced testicular injury treatment.

Effects of Administering the Soybean Isoflavone Genistein on Alkaline Phosphatase Levels During Orthodontic Tooth Movement in Young and Old Rabbits

The goal of this study was to investigate differences in alkaline phosphatase (ALP) levels in young and old rabbits after administering the soybean isoflavone genistein during orthodontic tooth movement. Twelve rabbits were used and assigned to four groups (n = 3); OG (old rabbits), OGS (old rabbits + soybean), YG (young rabbits), and YGS (young rabbits + soybean). The rabbit mandibulary incisors were distalised using a nickel-titanium open coil spring (50 g force). Genistein was administered from the initial orthodontic force delivery until day 21, at a dose of 1.2 mg/kg BW once a day. ALP levels (U/mg) were measured on days 1, 7, 14, 21 after orthodontic force delivery using a UV-Vis 6300 spectrophotometer at a 405 nm wavelength. The results were analysed by one-way analysis of variance followed by Tukey’s Honest Significant Difference (HSD) test (p &lt; 0.05). The ALP levels between the young and old age groups were significantly different. ALP levels were highest in the YGS group, and significantly lowest in the OG group (p &lt; 0.05). Moreover, the ALP level of the OGS group was significantly higher than that in the OG group (p &lt; 0.05). In conclusion, daily consumption of soybean isoflavone genistein could enhance ALP levels during orthodontic tooth movement, particularly in older rabbits.

Effect of a diet containing a mixture of soybean isoflavones and soyasaponins on contact hypersensitivity and gut microbiota in mice

AbstractDietary soybean isoflavones (SIs) and soyasaponins (SSs) individually exert inhibitory effects on contact hypersensitivity (CHS), which is an animal model of allergic contact dermatitis (ACD); however, the beneficial effects of diets containing a mixture of SIs and SSs on CHS remain unclear. Here, we investigated the CHS‐suppressive effects of diets containing a mixture of SIs and SSs at physiologically relevant doses, and the role of the gut microbiota. The diets attenuated ear swelling and reduced the number of Gr‐1‐positive cells infiltrating the auricle tissues. Ear swelling was inhibited in the SI‐ and SS‐treated mice compared to the SI‐treated mice. Compared to the CHS controls, the levels of chemokine (C‐X‐C motif) ligand 2 and triggering receptor expressed on myeloid cells‐1 (TREM‐1) were lower in the auricle tissues of SI‐ and SS‐treated mice, whereas TREM‐1 production was not suppressed in SI‐ or SS‐treated mice. In addition, vancomycin treatment had little effect on the CHS‐inhibitory activity of SI and SS diets, whereas ciprofloxacin and metronidazole treatments blocked the effects of SI and SS diets. These antibiotics exhibited differing effects on the microbiota composition deduced from the bacterial 16S ribosomal RNA gene sequences. Therefore, consuming a mixture of SIs and SSs has ACD‐preventive effects and is affected by the gut microbiota.

Metabolic Engineering of Isoflavones: An Updated Overview

Isoflavones are ecophysiologically active secondary metabolites derived from the phenylpropanoid pathway. They were mostly found in leguminous plants, especially in the pea family. Isoflavones play a key role in plant–environment interactions and act as phytoalexins also having an array of health benefits to the humans. According to epidemiological studies, a high intake of isoflavones-rich diets linked to a lower risk of hormone-related cancers, osteoporosis, menopausal symptoms, and cardiovascular diseases. These characteristics lead to the significant advancement in the studies on genetic and metabolic engineering of isoflavones in plants. As a result, a number of structural and regulatory genes involved in isoflavone biosynthesis in plants have been identified and characterized. Subsequently, they were engineered in various crop plants for the increased production of isoflavones. Furthermore, with the advent of high-throughput technologies, the regulation of isoflavone biosynthesis gains attention to increase or decrease the level of isoflavones in the crop plants. In the review, we begin with the role of isoflavones in plants, environment, and its benefits in human health. Besides, the main theme is to discuss the updated research progress in metabolic engineering of isoflavones in other plants species and regulation of production of isoflavones in soybeans.

Differential Gene Expression Associated with Altered Isoflavone and Fatty Acid Contents in Soybean Mutant Diversity Pool.

Soybean seeds are consumed worldwide owing to their nutritional value and health benefits. In this study we investigated the metabolic properties of 208 soybean mutant diversity pool (MDP) lines by measuring the isoflavone and fatty acid contents of the seed. The total isoflavone content (TIC) ranged from 0.88 mg/g to 7.12 mg/g and averaged 3.08 mg/g. The proportion of oleic acid among total fatty acids (TFA) ranged from 0.38% to 24.66% and averaged 11.02%. Based on the TIC and TFA among the 208 MDP lines, we selected six lines with altered isoflavone content and six lines with altered oleic acid content compared with those of the corresponding wild-types for measuring gene expression. Each of twelve genes from the isoflavone and fatty acid biosynthesis pathways were analyzed at three different seed developmental stages. Isoflavone biosynthetic genes, including CHI1A, IFS1, and IFS2, showed differences in stages and expression patterns among individuals and wild-types, whereas MaT7 showed consistently higher expression levels in three mutants with increased isoflavone content at stage 1. Expression patterns of the 12 fatty acid biosynthetic genes were classifiable into two groups that reflected the developmental stages of the seeds. The results will be useful for functional analysis of the regulatory genes involved in the isoflavone and fatty acid biosynthetic pathways in soybean.

Neuroprotective Potency of Tofu Bio-Processed Using Actinomucor elegans against Hypoxic Injury Induced by Cobalt Chloride in PC12 Cells

Fermented soybean products have attracted great attention due to their health benefits. In the present study, the hypoxia-injured PC12 cells induced by cobalt chloride (CoCl2) were used to evaluate the neuroprotective potency of tofu fermented by Actinomucor elegans (FT). Results indicated that FT exhibited higher phenolic content and antioxidant activity than tofu. Moreover, most soybean isoflavone glycosides were hydrolyzed into their corresponding aglycones during fermentation. FT demonstrated a significant protective effect on PC12 cells against hypoxic injury by maintaining cell viability, reducing lactic dehydrogenase leakage, and inhibiting oxidative stress. The cell apoptosis was significantly attenuated by the FT through down-regulation of caspase-3, caspases-8, caspase-9, and Bax, and up-regulation of Bcl-2 and Bcl-xL. S-phase cell arrest was significantly inhibited by the FT through increasing cyclin A and decreasing the p21 protein level. Furthermore, treatment with the FT activated autophagy, indicating that autophagy possibly acted as a survival mechanism against CoCl2-induced injury. Overall, FT offered a potential protective effect on nerve cells in vitro against hypoxic damage.

A Novel Role of Nuclear and Membrane Receptor on Isoflavone-Induced Neuritogenesis and Synaptogenesis

Thyroid hormone (TH) receptor (TR) and estrogen receptor (ER) play crucial roles in brain development. TR and ER are involved in dendrite growth, spines, and synapse formation in neurons. Soybean isoflavones, such as genistein, daidzein, and daidzein metabolite, S-equol are known to exert their action through TR, ER, and GPER1, a G-protein-coupled ER. However, the mechanisms of isoflavones action on brain development, especially during neuritogenesis and synaptogenesis, have not yet been extensively studied. We evaluated the effects of isoflavones using mouse primary cerebellar culture, astrocyte-enriched culture, Neuro-2A clonal cells, and co-culture with neurons and astrocytes. Soybean isoflavone augmented TH- or estradiol (E2)-mediated dendrite arborization of Purkinje cells. Such augmentation was suppressed by G15, a selective GPER1 antagonist, and ICI 182.780, an antagonist for ERs in both cultures. The knockdown of nuclear TRs or ERs also significantly reduced the dendrite arborization of Purkinje cells. It also increased the mRNA levels of TH-responsive genes, including Mbp, Bdnf, Rc3, Ntf3, Camk2b, Hr, and also Syn1, Syp, and Psd95 that are involved in synaptic plasticity. Isoflavones also increased the protein levels of synapsin-1, synaptophysin, and PSD95 in dendrite and membrane fraction of the cerebellar culture. To study further the molecular mechanism, we used Neuro-2A clonal cells. Isoflavones also induced neurite growth of Neuro-2A. The knockdown of TRs, ERs, and GPR30 by RNAi reduced isoflavones-induced neurite growth. Moreover, the co-culture study of Neuro-2A and astrocytes also showed an increase in isoflavones-induces neurite growth. In addition, isoflavones increased the localization of synapsin-1 or synaptophysin and F-actin in filopodia tips during Neuro-2A differentiation. The knockdown of nuclear ERs or GPR30 significantly reduced the number of filopodia and synapsin-1 or synaptophysin expression levels in neurite and membrane fractions. However, there are no significant effects of filopodia formation after co-culture with astrocytes. These results indicate that nuclear ERs and TRs play an essential role in isoflavones-induces neuritogenesis. Non-genomics signaling through membrane receptor and F-actin are necessary for the isoflavones-induces synaptogenesis. Astrocytes-neurons communication also increased isoflavones-induced neuritogenesis, but not synaptogenesis.

Effect of Exogenous Melatonin on the Quality of Soybean and Natto Products under Drought Stress

Melatonin can directly or indirectly eliminate reactive oxygen species, regulate hormone levels, and improve drought-stressed soybean crop resistance, yield, and quality. The nutrient contents of soybeans grown under normal conditions (WW), drought stress (D), and drought stress with exogenous melatonin (D + M) ( p &lt; 0.05 ) were compared. The differences in the quality of natto from the three groups of soybeans were also analyzed. The results showed that compared with soybeans under normal conditions, those grown under drought stress had reduced yield and carbohydrate, protein, essential amino acid, soybean isoflavone, and other nutrient contents. Besides, natto presented low nattokinase levels (674 U/mL), natto drawing ability was weak, the surface was dull, the taste was poor, and the sensory score was 12 points. Exogenous melatonin increased the carbohydrate content (starch, sucrose, glucose, and fructose) and improved the yield and quality of soybeans under drought. The natto produced by soybeans under drought stress with exogenous melatonin had high nattokinase content (756 U/mL) and long wire drawing. The surface of the product was rich in mucus and had a natto aroma. Its comprehensive sensory score was 20 points. Natto from soybeans under drought stress that were treated with exogenous melatonin showed significantly higher yield, nutrient content, and quality, than those under drought stress without treatment. This study provides theoretical data that can facilitate the development of new methods to improve the quality of soybeans grown under drought conditions.

Utilization of Isoflavones in Soybeans for Women with Menopausal Syndrome: An Overview.

Based on their nutrient composition, soybeans and related foods have been considered to be nutritious and healthy for humans. Particularly, the biological activity and subsequent benefits of soy products may be associated with the presence of isoflavone in soybeans. As an alternative treatment for menopause-related symptoms, isoflavone has gained much popularity for postmenopausal women who have concerns related to undergoing hormone replacement therapy. However, current research has still not reached a consensus on the effects of isoflavone on humans. This overview is a summary of the current literature about the processing of soybeans and isoflavone types (daidzein, genistein, and S-equol) and supplements and their extraction and analysis as well as information about the utilization of isoflavones in soybeans. The processes of preparation (cleaning, drying, crushing and dehulling) and extraction of soybeans are implemented to produce refined soy oil, soy lecithin, free fatty acids, glycerol and soybean meal. The remaining components consist of inorganic constituents (minerals) and the minor components of biologically interesting small molecules. Regarding the preventive effects on diseases or cancers, a higher intake of isoflavones is associated with a moderately lower risk of developing coronary heart disease. It may also reduce the risks of breast and colorectal cancer as well as the incidence of breast cancer recurrence. Consumption of isoflavones or soy foods is associated with reduced risks of endometrial and bladder cancer. Regarding the therapeutic effects on menopausal syndrome or other diseases, isoflavones have been found to alleviate vasomotor syndromes even after considering placebo effects, reduce bone loss in the spine and ameliorate hypertension and in vitro glycemic control. They may also alleviate depressive symptoms during pregnancy. On the other hand, isoflavones have not shown definitive effects regarding improving cognition and urogenital symptoms. Because of lacking standardization in the study designs, such as the ingredients and doses of isoflavones and the durations and outcomes of trials, it currently remains difficult to draw overall conclusions for all aspects of isoflavones. These limitations warrant further investigations of isoflavone use for women’s health.

Non-digestive stachyose enhances bioavailability of isoflavones for improving hyperlipidemia and hyperglycemia in mice fed with high fat diet.

This study examined the efficacy of non-digestive stachyose on enhancing the absorption of soy isoflavones to improve metabolic syndrome in C57/BL6 mice. UPLC-q/TOF-MS was employed to analyze the content of isoflavones in urine and faeces. Stachyose significantly increased urinary contents of total isoflavones, genistein, daidzein and glycitein in mice. Supplementation of stachyose, soybean isoflavones or a combination prevented high fat diet (HFD)-induced body weight gain, accumulated adipose, dyslipidemia and hyperglycemia in obese mice. Interestingly, co-supplementation of stachyose and isoflavones improved all the mentioned parameters more effectively than administration of stachyose or isoflavones alone. Histological observation of hepatic tissues also confirmed the beneficial effects of co-supplementation of stachyose and isoflavones. These findings suggest that co-ingestion of non-digestible oligosaccharides and polyphenols as normal diet is a promising potential strategy for managing or reducing the risk of metabolic syndrome, which will lead to new knowledge on whole soybean and have extensive application in development of healthy food.

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 2g feed samples ground to 2mm were incubated in the rumen for 0, 2, 4, 8, 16 and 24h. The effective degradability (ED) of DM, daidzein, genistein, glycitein and total isoflavones was calculated at outflow rate of 0.06h. 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 16h 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.

Analysis of chemical constituents of Ginseng-Douchi compound fermentation products based on UPLC-Q-TOF-MS

In this experiment, ultra high performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) was used to analyze and identify chemical constituents of Ginseng-Douchi(GD) compound fermentation, and explore the conversion rules of ginsenosides and soybean isoflavones after compound fermentation. Waters Acquity UPLC BEH C_(18) column(2.1 mm×100 mm, 1.7 μm) was adopted, with 0.1% formic acid aqueous solution(A)-0.1% formic acid acetonitrile solution(B) as mobile phase for gradient elution; electrospray ion source(ESI) was used to collect data in positive and negative ion modes; according to the exact mass number, the secondary spectrum comparison of the database and the existing literature reports, Peakview 2.0/masterview 1.0 software was used to determine the common ion structure formula. Finally, a total of 133 chemical constituents were analyzed and identified from the GD. Ginseng saponins and isoflavone glycosides were significantly converted after fermentation. Among them, peak areas of prototype ginsenosides Rk_3, Rh_1, Rh_2, Rh_3, daidzin, glycitin and genistin decreased significantly; whereas peak areas of se-condary ginsenoside Rb_1, Rb_2, Rk_1, glycitein, genistein and daidzein increased significantly. In this experiment, liquid-mass spectrometry technique was used to investigate the conversion of active ingredients of GD compound fermented products after co-fermentation, so as to provide a scientific basis for elucidating pharmacodynamics material basis and quality control.

Differences in Cotyledon Color and Harvest Period Affect the Contents of Major Isoflavones and Anthocyanins in Black Soybeans

Several environmental and genetic factors affect the isoflavone and anthocyanin contents in soybeans. This study aimed to assess the influences of cotyledon color and harvest period on the contents of five major isoflavones and three major anthocyanins in 323 black soybean landraces grown in Korea. In all the soybeans, malonylgenistin, malonyldaidzin and cyanidin-3-O-glucoside were the foremost components. The total isoflavone (TIC) and total anthocyanin (TAC) contents were in the ranges of 491.29-1998.39 μg/g and 452.60-2789.37 mg/100 g on dry weight basis, respectively. Both the average TIC and TAC were higher in green cotyledon soybeans (1493.93 μg/g and 1656.05 mg/100 g, respectively) than in yellow cotyledon soybeans (1423.09 μg/g and 1489.30 mg/100 g, respectively). With respect to the harvest period, the average TIC was in the order of Late-October (1517.31 μg/g) > Mid-October (1454.54 μg/g) > Early-October (1340.95 μg/g). Moreover, the average TAC decreased in the order of Late-October (1765.76 mg/100 g) > Mid-October (1503.93 mg/100 g) > Early-October (1350.91 mg/100 g). In general, cotyledon color appeared to cause a significant variation on TAC (P 1800 μg/g) and TAC (> 2000 mg/100 g) in their seeds and hence, could be considered as important sources of dietary isoflavones and anthocyanins. Besides, they possibly provide a wide spectrum of options if considered during the development of improved soybean genotypes.

Anti-aging effect of Lactobacillus plantarum HFY09-fermented soymilk on D-galactose-induced oxidative aging in mice through modulation of the Nrf2 signaling pathway

Abstract After soymilk fermented by L. plantarum HFY09, the bound soybean isoflavones content was reduced, but free soybean isoflavones and peptides increased. In vivo results show that L. plantarum HFY09-fermented soymilk increased the T-SOD, MDA, GSH-Px, GSH, CAT, and NO in the serum, liver, and brain tissues of mice. The aforementioned soymilk also increased the Col I and hyaluronic acid, and reduced the contents of Col III, H2O2, and AGEs in the skin. L. plantarum HFY09-fermented soymilk upregulated Nrf2, HO-1, NOS1, NOS3, SOD1, SOD2, CAT, Nqol, Gclm expression in the liver and the spleen, reduced the NOS2 expression, and upregulated SOD1 SOD2, CAT, GSH-Px, TIMP1, and TIMP2 expression in skin, downregulated MMP3, and MMP9 expression. These results show that L. plantarum HFY09-fermented soymilk could effectively alleviate aging in D-galactose-induced aging mice, the mechanism may be related to the activation of Nrf2 signaling pathway by soy isoflavone aglycone and small molecule peptides.

Effects of Soybean Isoflavone and Astragalus Polysaccharide Mixture on Colostrum Components, Serum Antioxidant, Immune and Hormone Levels of Lactating Sows

Simple SummaryThe reproductive performance of sows plays an important role in the development of the pig industry. The health status during gestation and lactation capacity of sows determines the healthy development and later growth status of piglets. This study aimed to investigate the effects of soybean isoflavone and astragalus polysaccharide mixture on the colostrum components, and serum antioxidant activities, immune function, and hormone levels of lactating sows. Results showed that the soybean isoflavone and astragalus polysaccharide mixture increased the total lactation yield in the lactating phase, and improved the antioxidant, immune and hormone levels in the serum of lactating sows. In conclusion, the soybean isoflavone and astragalus polysaccharide mixture can improve the average daily feed intake, lactation yield, serum antioxidant activity, immune function, and the hormone levels of lactating sows, and the optimum dosage in this study was 200 mg/kg. This study provides a theoretical basis for the application of the soybean isoflavone and astragalus polysaccharide mixture application in the production of lactating sows and a reference basis for the development of green feed additives.The objectives of this study were to investigate the effects of soybean isoflavone (SI) and astragalus polysaccharide (APS) mixture on the colostrum components, serum antioxidant, immune and hormone levels of lactating sows. A total of 72 healthy Yorkshire × Landrace lactating sows, were randomly divided into four treatments with six replicates and three lactating sows for each replicate. The control group was fed the basal diet, while the experimental groups were fed the basal diet with 100, 200 and 300 mg/kg SI and APS mixture in the form of powder, respectively. Compared with the control group, (a) the total lactation yield of the 200 mg/kg group was significantly higher (p < 0.05) at 21 days, (b) there was no significant difference in colostrum composition, (c) TG, CHO and MDA content in each treatment group were significantly decreased (p < 0.05), (d) IgA, GH, IGF-1, TNF-α and SOD contents in the 200 mg/kg group were significantly increased (p < 0.05). The SI and APS mixture could improve the average daily feed intake, lactation yield, serum antioxidant activities, immune function, and hormone levels of lactating sows, and the optimum dosage in this study was 200 mg/kg.

Biotransformed Antioxidant isoflavone extracts present high-capacity to attenuate the in vitro formation of advanced glycation end products

ABSTRACT Advanced glycation end products (AGEs) are toxic with a high capacity to cause damages to health, mainly associated with diabetes complications. In this study, soybean isoflavone extracts were subjected to different biotransformation processes: Lactobacilli fermentation, Enzymatic and Enzymatic followed by fermentation, in order to improve their antioxidant capacity and bioactive isoflavone content. The effects of the biotransformation processes on total phenolic content, antioxidant activities, and isoflavone profile were evaluated. Analyses of antiglycation activity of the isoflavones extracts were evaluated by glycation models in vitro. The results showed that all bioprocesses increased the aglycone content, as well as the antioxidant capacity by about 2.5 times using ORAC and 1.6 times using FRAP assays. The results were superior for enzymatic biotransformation followed by fermentation. All processes showed about 24,33% to 57,33% of anti-glycationt capacity, indicating that biotransformation improved the bioactivity of isoflavones extracts for glycation inhibitory activity, as well as the associated e antioxidant capacity.

Analysis of Main Components and Prospects of Natto

The word “natto” originated from Japan, which was known as stinky bean, salt bean or silk bean in Chinese folk. Natto contains multiple functional components, including nattokinase, soybean isoflavone, γ-polyglutamic acid, vitamin K2, biogenic amines, SOD, small-molecule polypeptide, which has good preventive and curative effects for many diseases, such as cardiovascular and cerebrovascular diseases, hyperlipidemia, hypertension, menopausal symptoms and hypoimmunity. Along with the aging population in the world and China, it is urgent to improve the quality of life. It is necessary to enhance the understanding of natto-related knowledge, expand propaganda power, accept natto consciously and eat natto frequently, which is good for our health and helps our country to build a healthy and harmonious society. This review will descript the development, components, functions and prospects of natto, which help us to offer theoretical basis for promoting natto industry.

Identification of Potential Human Protein Targets for Soybean Isoflavones

Soy isoflavones have been reported as endocrine disruptors due to their ability to modulate the activity of estrogen receptors (ERs) in mammals; however, its ability to modulate other metabolic pathways is not entirely clear, which makes it necessary to identify new pharmacological targets that interact with these compounds present in soybean. In this work, a virtual screening was executed to identify potential targets of nine soy isoflavones, employing human proteins target from PharmMapper. The best 25 fit scores were selected and prepared for AutoDock Vina docking protocols. The results suggest that equol, daidzein and biochanin A, have the potential to interact with targets such as phenylethanolamine N-methyltransferase, sex hormone-binding globulin and vitamin D3 receptor, respectively. The validations of docking protocols showed good pose reproducibility (root-mean-square deviation (RMSD) ranged 0.001-3.854 Å) and a modest correlation between binding affinities and agonist concentration, AC50 (correlation coefficient (R) = 0.643, p &lt; 0.001). Protein interaction network revealed that predicted targets for soy isoflavones are involved in different pathways, including neurotransmission, metabolism, and cancer remarking the need of a better understanding of the effects of these compounds on human health.

Release of Soybean Isoflavones by Using a β-Glucosidase from Alicyclobacillus herbarius.

β‐Glucosidases are used in the food industry to hydrolyse glycosidic bonds in complex sugars, with enzymes sourced from extremophiles better able to tolerate the process conditions. In this work, a novel β‐glycosidase from the acidophilic organism Alicyclobacillus herbarius was cloned and heterologously expressed in Escherichia coli BL21(DE3). AheGH1 was stable over a broad range of pH values (5–11) and temperatures (4–55 °C). The enzyme exhibited excellent tolerance to fructose and good tolerance to glucose, retaining 65 % activity in the presence of 10 % (w/v) glucose. It also tolerated organic solvents, some of which appeared to have a stimulating effect, in particular ethanol with a 1.7‐fold increase in activity at 10 % (v/v). The enzyme was then applied for the cleavage of isoflavone from isoflavone glucosides in an ethanolic extract of soy flour, to produce soy isoflavones, which constitute a valuable food supplement, full conversion was achieved within 15 min at 30 °C.

Effect of Kefir on Soybean Isoflavone Aglycone Content in Soymilk Kefir.

Kefir is a traditional fermented milk originating in the Caucasus area and parts of Eastern Europe. In this study, the kefir culture, which is modified upon the addition of lactic acid bacteria (LAB) cells, specifically for soymilk kefir fermentation with the highest capacity of isoflavone biotransformation, was successfully produced, and the metagenomics composition of soymilk or milk fermented using these kefir cultures was investigated. The metagenome analysis showed that the microbiota of kefir in M-K (milk inoculated with kefir), SM-K (equal volumes of soymilk and milk inoculated with kefir), and S-K (pure milk inoculated with kefir) were related to the addition of soymilk or not. Furthermore, the HPLC chromatogram revealed that Guixia 2 (Guangzhou, China) may be a good source of soymilk kefir fermentation due to its high isoflavone aglycone content (90.23 ± 1.26 μg/g in daidzein, 68.20 ± 0.74 μg/g in genistein). Importantly, the starter culture created by adding 1.5 g probiotics (Biostime®, Guangzhou, China) to Chinese kefir showed a significant increase in the levels of isoflavone aglycones (72.07 ± 0.53 μg/g in isoflavone aglycones). These results provided insight into understanding the suitable soybean cultivar and starter cultures, which exhibit promising results of isoflavone biotransformation and flavor promotion during soymilk kefir fermentation.