Isoflavone Extract Research Articles

Soybean isoflavones ameliorate ischemic cardiomyopathy by activating Nrf2-mediated antioxidant responses.

Ischemic cardiomyopathy (IC) is the major cause of heart failure. Conventional medicine has been proved ineffective with adverse effects. Soybean presents exciting adjunctive therapies and shows protective benefits for IC. However, the molecular mechanisms remain unclear. Isoflavones are the main bioactive components of soybean and may be protective against heart disease. Isoflavones were extracted by using an acidic-ethanol method and analyzed by HPLC. All patients with ischemic stroke were randomly and evenly assigned to two groups: the isoflavone group (80 mg day-1, n = 100) and control group (80 mg day-1 placebo, n = 100), and the whole period of the experiment was 24 weeks. The effects of soybean isoflavone on brachial flow-mediated dilatation (FMD) were measured. HPLC fractionation shows that isoflavone extracts are mainly composed of 55% genistein, 23% daidzein, and 14% glycitein. Isoflavone therapy reduced more levels of triglyceride and LDL-c in females than in males. FMD was higher in the isoflavone group than in the control group after 24-week therapy (treatment effect 2.0%, 95% CI 0.18-3.0, P = 0.01). The baseline differences were adjusted in FMD and the isoflavone therapies were closely associated with the reduction of FMD impairment at 24 weeks (odds ratio 0.30, 95% CI 0.14-0.85, P = 0.01). The effects of isoflavone on brachial FMD were negatively associated with base FMD (r = -0.65, P < 0.01). Furthermore, isoflavone therapy caused a significant increase in the levels of erythroid-derived 2-like 2 (Nrf2), superoxide dismutase (SOD) and a significant decrease in serum levels of C-reactive protein, 8-isoprostane, malondialdehyde, interleukin-6 and tumor necrosis factor alpha. In contrast, the isoflavones had no effects on the levels of oxidation-related molecules when Nrf2 was silenced. These results suggest that soybean isoflavones ameliorate IC patients by improving their antioxidant capacities via the upregulation of Nrf2.

Improving Free Radical Scavenging Activity of Soy Isoflavone Glycosides Daidzin and Genistin by 3'-Hydroxylation Using Recombinant Escherichia coli.

The present study describes the biotransformation of a commercially available crude extract of soy isoflavones, which contained significant amounts of the soy isoflavone glycosides daidzin and genistin, by recombinant Escherichia coli expressing tyrosinase from Bacillus megaterium. Two major products were isolated from the biotransformation and identified as 3′-hydroxydaidzin and 3′-hydroxygenistin, respectively, based on their mass and nuclear magnetic resonance spectral data. The two 3′-hydroxyisoflavone glycosides showed potent 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity with IC50 values of 7.4 and 9.8 μM for 3′-hydroxydaidzin and 3′-hydroxygenistin, respectively. The free radical scavenging activities of the two 3′-hydroxyisoflavone glycosides were, respectively, 120 and 72 times higher than the activity of their precursors, daidzin and genistin, and were also stronger than the activity of ascorbic acid, which showed an IC50 value of 15.1 μM. This is the first report of the bio-production and potential antioxidant applications of both 3′-hydroxydaidzin and 3′-hydroxygenistin.

Effects of a standardised extract of Trifolium pratense (Promensil) at a dosage of 80 mg in the treatment of menopausal hot flushes: A systematic review and meta-analysis

ObjectiveTo critically assess the evidence for a specific standardised extract of Trifolium pratense isoflavones (Promensil) at a dosage of 80mg/day in the treatment of menopausal hot flushes. Data sourcesSystematic literature searches were performed in Medline, Scopus, CINAHL Plus, Cochrane, AMED and InforRMIT and citations obtained from 1996 to March 2016. Reference lists were checked; corresponding authors contacted and the grey literature searched for additional publications. Review methodsStudies were selected according to predefined inclusion and exclusion criteria. All randomised clinical trials of a specific standardised extract of Trifolium pratense isoflavones (Promensil) used as a mono-component at 80mg/day and measuring vasomotor symptoms were included. The data extraction and quality assessment were performed independently by one reviewer and validated by a second with any disagreements being settled by discussion. Weighted mean differences and 95% confidence intervals were calculated for continuous data using the fixed-effects model. ResultsTwenty potentially relevant papers were identified, with only five studies meeting the inclusion criteria. The meta-analysis demonstrated a statistical and clinically relevant reduction in hot flush frequency in the active treatment group compared to placebo. Weighted mean difference 3.63 hot flushes per day: [95% CI 2.70–4.56]; p˂0.00001). Due to a lack of homogeneity a priori defined sub-group analyses were performed demonstrating a substantive difference between cross-over and parallel-arm clinical trial designs. ConclusionThere is evidence for a statistical and clinically significant benefit for using a specific standardised extract of red clover isoflavones (Promensil) at 80mg/day for treating hot flushes in menopausal women across the 3 studies included in the meta-analysis. The preparation was safe over the short-term duration of the studies (3 months).

Isoflavone Extracts Enhance the Effect of Epidermal Growth Factor Receptor Inhibitors in NSCLC Cell Lines.

We investigated the effects of the pharmacological inhibition in vitro of epidermal growth factor receptor (EGFR) in combination with isoflavones. Four anticancer drugs (erlotinib, gefitinib, afatinib and AZD9291) were combined with soy and red clover isoflavone extracts and used in cellular proliferation assays. The antitumor activity of inhibitors alone and in combination with isoflavone extracts was compared on three non-small cell lung cancer (NSCLC) cell lines with affiant EGFR genotype: A549 (EGFR wt); H1795 (EGFR T790M); HCC827 (EGFR del E746-A750). Combined treatment with extracts significantly enhanced the antiproliferative activity of all inhibitors against these cell lines. Bioactive compounds of extracts may synergize the antitumor efficacy of the inhibitors. To date, as far as we are aware, this is the first report of the combined effect of isoflavone extracts and EGFR inhibitors on human NCSLC cell growth. Sequential treatment with these drugs combined with isoflavones may represent the basis for a new therapeutic approach.

Isoflavone extract being a potential therapeutic agent for inflammatory skin diseases

Isoflavone extract being a potential therapeutic agent for inflammatory skin diseases

Pressurized water extraction of isoflavones by experimental design from soybean flour and Soybean Protein Isolate

A Doehlert experimental design was conducted and surface response methodology was used to determine the effect of temperature, contact time and solid liquid ratio on isoflavone extraction from soybean flour or Soybean Protein Isolate in pressurized water system. The optimal conditions conducted gave an extraction yield of 85% from soybean flour. For Soybean Protein Isolate compared to soybean flour, the isoflavone extraction yield is 61%. This difference could be explained by higher aglycon content, while aglycon appears to be the least extracted isoflavone by pressurized water. The solid liquid ratio in the ASE cell was the overriding factor in obtaining high yields with both soybean products, while temperature has less influence. A high temperature causes conversion of the malonyls-glucosides and glucosides isoflavone derivatives into glucosides or aglycons forms. pressurized water extraction showed a high solubilization of protein material up to 95% of inserted Soybean Protein Isolate.

Integrated extraction and purification of soy isoflavones by using aqueous micellar systems

In this work, an integration of solid-liquid and liquid-liquid extractions by using aqueous micellar two-phase systems was evaluated as potential tool to purify soy isoflavones. Additionally, the proposed methodology aimed to preserve the protein content of the processed soy flour. The extractive assays were performed in AMTPS formed by Triton X-114 and sodium tartrate. In order to optimize the purification process, temperature and time were evaluated as independent variables. Under optimal working conditions, i.e. 100min and 33°C of incubation, IF were purified with a recovery percentage of 93 and a purification factor of almost 10. More importantly, the obtained sample presented an aglycone proportion superior to the reported by other methodologies. These results open perspectives to the use of aqueous micellar two-phase systems as an integrative methodology to extract, concentrate and purify isoflavones.

Nanospray Drying as a Novel Tool to Improve Technological Properties of Soy Isoflavone Extracts.

Pharmacological evidences have correlated a low incidence of osteoporosis, breast cancer, cardiovascular disease, and colon cancer in Asian populations, high consumers of soya, to the properties of soy isoflavones, more specifically to daidzein and genistein. However, in spite of the potent biological activity, their poor water solubility has a strong negative effect on bioavailability. In this study, an innovative technique, nano spray drying, was used to obtain nanoparticles loaded with a soybean dry extract while carboxymethyl cellulose was used as the excipient. The optimization of the process conditions allowed for the manufacturing of stable nanoparticles with a mean size of around 650 nm, a narrow size distribution, and a high encapsulation efficiency (between 78 % and 89 %). The presence of carboxymethyl cellulose was able to stabilize the isoflavone extract and enhance its affinity with aqueous media, strongly increasing its permeation through biological membranes up to 4.5-fold higher than pure soy isoflavone extract raw material and twice its homologous minispray-dried formulation. These results are very useful for the administration of the extract, either topically or orally, suggesting that the isoflanones extract nanoparticulate powder obtained by nano spray drying has great potential to enhance extract bioavailability and could be used as an ingredient to be enclosed in dietary supplements and nutraceutical and cosmeceutical products.

Effects of Isoflavone-Enriched Feed on the Rumen Microbiota in Dairy Cows.

In this study, we compared the effects of two diets containing different isoflavone concentrations on the isoflavone transfer from feed into milk and on the rumen microbiota in lactating dairy cows. The on-farm experiment was conducted on twelve lactating Czech Fleckvieh x Holstein cows divided into two groups, each with similar mean milk yield. Twice daily, cows were individually fed a diet based on maize silage, meadow hay and supplemental mixture. Control group (CTRL) received the basal diet while the experimental group (EXP) received the basal diet supplemented with 40% soybean isoflavone extract. The average daily isoflavone intake in the EXP group (16 g/day) was twice as high as that in the CTRL group (8.4 g/day, P<0.001). Total isoflavone concentrations in milk from the CTRL and EXP groups were 96.89 and 276.07 μg/L, respectively (P<0.001). Equol concentrations in milk increased from 77.78 μg/L in the CTRL group to 186.30 μg/L in the EXP group (P<0.001). The V3-4 region of bacterial 16S rRNA genes was used for metagenomic analysis of the rumen microbiome. The experimental cows exhibited fewer OTUs at a distance level of 0.03 compared to control cows (P<0.05) and reduced microbial richness compared to control cows based on the calculated Inverse Simpson and Shannon indices. Non-metric multidimensional scaling analysis showed that the major contributor to separation between the experimental and control groups were changes in the representation of bacteria belonging to the phyla Bacteroidetes, Proteobacteria, Firmicutes, and Planctomycetes. Surprisingly, a statistically significant positive correlation was found only between isoflavones and the phyla Burkholderiales (r = 0.65, P<0.05) and unclassified Betaproteobacteria (r = 0.58, P<0.05). Previous mouse and human studies of isoflavone effects on the composition of gastrointestinal microbial populations generally report similar findings.

Glycone-rich Soy Isoflavone Extracts Promote Estrogen Receptor Positive Breast Cancer Cell Growth

ABSTRACTDue to the association of hormone replacement therapy (HRT) with breast cancer risk, estrogenically active soy isoflavones are considered as an HRT alternative to alleviate menopausal symptoms. However, several recent reports challenged the health benefits of soy isoflavones and associated them with breast cancer promotion. While glyconic isoflavones are the major constituents of soybean seeds, due to their low cell permeability, they are considered to be biologically inactive. The glyconic isoflavones may exert their effects on membrane-bound estrogen receptors or could be converted to aglycones by extracellular β-glucosidases. Therefore, we hypothesized that despite their low cell permeability, soybean cultivars with high glyconic isoflavones may promote breast cancer cell growth. To test this, composition and estrogenic activity of isoflavones from 54 commercial soybean cultivars were determined. Soybean seeds produced in identical climate and growth conditions were used to minimize the effects of extraneous factors on isoflavone profile and concentrations. The glyconic daidzin concentration negatively correlated with genistin and with other aglycones. Relative to control, isoflavone extracts from 51 cultivars were estrogenic and promoted the growth of estrogen receptor positive (ER+) breast cancer cell line MCF-7 from 1.14 to 4.59 folds and other three cultivars slightly reduced the growth. Among these, extracts from three cultivars were highly estrogenic and promoted MCF-7 cell growth by 2.59–4.64 folds (P<0.005). Among six isoflavones, daidzin was positively associated with MCF-7 cell growth (P<0.005, r = 0.13966), whereas the negative correlation between genistin and MCF-7 cell growth was nearly significant (P≤0.0562, r = −0.026141). Furthermore, in drug interaction studies daidzin-rich isoflavone extracts antagonized tamoxifen, an ER inhibitor. Taken together, our results suggest that the glyconic daidzin-rich soy isoflavone extracts may exert estrogenic effects and promote ER+ breast cancer growth.

A modified QuEChERS method coupled with high resolution LC-Q-TOF-mass spectrometry for the extraction, identification and quantification of isoflavones in soybeans

A modified QuEChERS method coupled with high resolution LC-Q-TOF-MS was established for the extraction, identification and quantification of six isoflavones in soybeans.

Metabolomic Analysis of Biochemical Changes in the Plasma of High-Fat Diet and Streptozotocin-Induced Diabetic Rats after Treatment with Isoflavones Extract of Radix Puerariae.

The main purpose of this study was to investigate the protective effects of total isoflavones from Radix Puerariae (PTIF) in diabetic rats. Diabetes was induced by a high-fat diet and intraperitoneal injection of low-dose streptozotocin (STZ; 40 mg/kg). At 26 weeks onwards, PTIF 421 mg/kg was administrated to the rats once daily consecutively for 10 weeks. Metabolic profiling changes were analyzed by Ultraperformance Liquid Chromatography-Quadrupole-Exactive Orbitrap-Mass Spectrometry (UPLC-Q-Exactive Orbitrap-MS). The principal component discriminant analysis (PCA-DA), partial least-squares discriminant analysis (PLS-DA), and orthogonal partial least-squares discriminant analysis (OPLS-DA) were used for multivariate analysis. Moreover, free amino acids in serum were determined by high-performance liquid chromatography with fluorescence detector (HPLC-FLD). Additionally, oxidative stress and inflammatory cytokines were evaluated. Eleven potential metabolite biomarkers, which are mainly related to the coagulation, lipid metabolism, and amino acid metabolism, have been identified. PCA-DA scores plots indicated that biochemical changes in diabetic rats were gradually restored to normal after administration of PTIF. Furthermore, the levels of BCAAs, glutamate, arginine, and tyrosine were significantly increased in diabetic rats. Treatment with PTIF could regulate the disturbed amino acid metabolism. Consequently, PTIF has great therapeutic potential in the treatment of DM by improving metabolism disorders and inhibiting oxidative damage.

Changes in isoflavone profiles and antioxidant activities in isoflavone extracts from soybeans and soyfoods under riboflavin photosensitization

Isoflavone extracts from soybeans and soyfoods were treated with riboflavin photosensitization and changes in antioxidant activities of isoflavone extracts under riboflavin sensitization were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. Extracts rich in malonyl derivatives, β-glucosides, and aglycones were prepared from raw, ovendried, and almond-incubated soybeans, and the fermented soyfoods cheongukjang and natto. As the period of visible light irradiation increased to 120 min, the total isoflavone content determined using HPLC decreased in all samples. Aglycones in almond-incubated extracts decreased by 77.5% after 120min, and β-glucosides in oven-dried extracts decreased by 52.0%. The radical scavenging activity based on DPPH and ABTS assays significantly (p 0.05) increased after riboflavin sensitization.

Abstract 777: Effects of Src inhibitors and soy isoflavones on human prostate cancer cells

Abstract Background: Src family kinases are often over-expressed and highly active in solid tumors, including prostate cancer. This phenotype is associated with a poor prognosis partly because Src is a key factor in important signaling pathways involved in cell proliferation, angiogenesis, and initiation of metastasis. As a result, several promising small molecule targeting agents have been developed to prevent phosphorylation of key tyrosine residues that produce Src activation. However, these agents are not without side effects. The purpose of this study was to determine if adding a cytostatic soy isoflavone extract (ISF) to the treatment would produce optimal results at lower doses of the Src inhibitor. The ISF used in these studies has been shown to inhibit tumor growth in mice carrying human prostate cancer cell xenografts without causing toxicity to the host. Methods: Aggressive PC-3ML cells (a gift from A. Fatatis, Drexel University), and weakly tumorigenic LNCaP cells were treated for 24 hr with various concentrations of Src inhibitors (dasatinib, saracatinib), ISF (200 ug/ml, NovaSoy), or a combination. To evaluate effects on the metastatic potential of the cells, functional assays of cell growth and motility were performed, including those that assess clonogenic cell survival, cell cycle progression, and transwell migration and invasion activity. Results: Src inhibitors and ISF alone produced very little reduction in cell viability, but significant cytostatic effects, as determined by a reduction in clonogenicity, the number of cells able to form 50-cell colonies. This was likely due, in part, to changes in cell cycle progression. Both dasatinib and saracatinib caused an accumulation of cells in the G1 phase. As expected, ISF treatment resulted in higher numbers of cells in the G2/M phase. When the treatments were combined, cells exposed to dasatinib were observed to accumulate in both phases, with a significant decrease in S-phase cells. The results were not significant for saracatinib-treated cells. Exposure to either a Src inhibitor or ISF significantly reduced the migration of cells in a transwell chamber and their ability to invade through a Matrigel-coated 8 micron-pore membrane towards a chemoattractant (media containing 10% FBS). Dasatinib produced much greater effects, and at lower concentrations, than saracatinib. When combined with ISF, the effects were enhanced, particularly with dasatinib. Conclusions: In vitro studies suggested that combining a Src inhibitor and ISF resulted in greater inhibition of metastatic potential than either alone. This may indicate that including ISF in treatment regimens may allow a lower dose of the targeting agent to be used to achieve optimal response and also decrease toxicity. Citation Format: Lori P. Rice, Christine Pampo, Sharon Lepler, Dietmar W. Siemann. Effects of Src inhibitors and soy isoflavones on human prostate cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 777. doi:10.1158/1538-7445.AM2015-777

Adsorption of isoflavones onto PVPP in the presence of a soy matrix

The adsorption of isoflavones from an okara extract onto polyvinyl polypyrrolidone (PVPP) was studied for a pH ranging from 4 to 7.In general, the affinity of aglycones to PVPP was around 10 times higher than the affinity of the glycosides. Towards lower pH, the adsorption performance improved for the glycosides, especially for the malonyl-glucosides, but not for the aglycones. Towards neutral pH the affinity also increased, and showed the highest affinity for the total amount of isoflavones. Due to a large amount of protein present in the extract, some isoflavones were lost at lower pH due to the precipitation of protein, which led to losses of 3–25% in the protein fraction without any addition of PVPP.Moreover, PVPP was added to the crude starting material (i.e. okara), investigating the effect of the matrix on the adsorption and the possibility to combine the extraction and adsorption process. The isoflavone extraction was modelled using affinity constants of isoflavones to the matrix and the PVPP. The simulation showed that concurrent PVPP addition results in more extraction from the isoflavones from the matrix.

Isoflavone profile in soymilk as affected by soybean variety, grinding, and heat-processing methods.

Isoflavones impart health benefits and their overall content and profile in foods are greatly influenced at each step during processing. In this study, 2 soybean varieties (Prosoy and black soybean) were processed with 3 different grinding (ambient, cold, and hot grinding) and heating methods (traditional stove cooking, 1-phase UHT, and 2-phase UHT) for soymilk making. The results showed after cold, ambient, and hot grinding, the total isoflavones were 3917, 5013, and 5949 nmol/g for Prosoy; the total isoflavones were 4073, 3966, and 4284 nmol/g for black soybean. Grinding could significantly increase isoflavone extraction. The grinding process had a destructive effect on isoflavones and this effect varied with grinding temperature. Different heating methods had different effects on different isoflavone forms. Two soybean varieties showed distinct patterns with respect to the change of isoflavone profile during processing.

An Optimized Method for the Quantification of Isoflavones in Dry Soy Extract Containing Products

Isoflavones, a class of flavonoids with estrogen-like activity, are present in the human diet mainly derived from soy-based foods. Soy isoflavones (namely genistein, daidzein, and glycitein and their derivatives) and concentrates have primarily been investigated for their ability to prevent sex hormone-dependent cancers and cardiovascular problems. Several studies demonstrated that many of the biological effects of soy are due to isoflavones. The aim of our study was to develop a simple method for the determination of isoflavones in dry soy extract containing products. Since biological effects of soy isoflavones depend upon aglycone forms, extracts were hydrolyzed to gain isoflavone aglycones. To optimize the extraction and hydrolysis of isoflavones, the effect of HCl concentration (1.5–6 N), hydrolysis time (25–210 min), and temperature (30–100 °C) on total isoflavone aglycone content was studied using an RP-HPLC-DAD method. By mathematical fitting and optimization methods, optimum hydrolysis conditions for maximizing the quantification of isoflavones were determined (t = 96 min, cHCl = 4.9 N, T = 80 °C). The experimentally verified model has a good coefficient of R 2 (0.9928), and the recovery of isoflavones was 97.81–102.76 %. The developed method allows reliable and maximum determination of isoflavones in dry soy extract containing products. Based on this method, six soy extract containing products were analyzed. Our experiments revealed significant variations in the isoflavone content and composition. These results highlight the necessity to clearly specify the isoflavone composition of soy products.

An improved calibrated normalized resolution product (r*') and the application in HPLC fingerprints of soy isoflavone extract

An improved calibrated normalized resolution product (r*') and the application in HPLC fingerprints of soy isoflavone extract

Enhancement of β-secretase inhibition and antioxidant activities of tempeh, a fermented soybean cake through enrichment of bioactive aglycones

Context: Soybean and its fermented products are the most common source of isoflavones in human food.Objective: The present study quantifies the major glycosides and aglycones in soybean and its fermented product tempeh isoflavone extracts. The comparision of antioxidant effects and BACE1 inhibitory activity between the isoflavones of soybean and tempeh were also established.Materials and methods: The major isoflavones such as daidzein and genistein (aglycones), and their sugar conjugates (glycosides) daidzin and genistin in soybean and tempeh isoflavones were quantified using HPLC analysis. Comparative studies on BACE 1 (β-site amyloid precursor protein cleaving enzyme 1 or β-secretase 1) inhibition and free-radical scavenging activities (diphenyl-1-picrylhydrazyl (DPPH) and ferrous ion chelating ability) were conducted.Results: The amount of actives (mg/100 g) in soybean isoflavone compared with tempeh isoflavone is as follows: daidzein 16.72 mg/100 g versus 38.91 mg/100 g, genistein 11.10 mg/100 g versus 24.03 mg/100 g, daidzin 6.16 mg/100 g versus 0.69 mg/100 g, and genistin 24.61 mg/100 g versus 6.57 mg/100 g. The IC50 values of soybean and tempeh isoflavones against BACE1 were 10.87 and 5.47 mg/ml, respectively. The tempeh isoflavone had a more potent DPPH free-radical scavenging activity (IC50 = 2.67 mg/ml) than the soybean isoflavone (IC50 = 10 mg/ml). The ferrous ion chelating ability of the isoflavones was practically similar (IC50 = 10.40 mg/ml, soybean and 11.13 mg/ml, tempeh).Discussion and conclusion: The present study indicates that tempeh is a healthy supplement to alleviate oxidative stress through the enrichment of aglycones.

Effect of soaking and fermentation on content of phenolic compounds of soybean (Glycine max cv. Merit) and mung beans (Vigna radiata [L] Wilczek)

Mung beans (Vigna radiata [L] Wilczek) purchased from a Spanish company as “green soybeans”, showed a different phenolic composition than yellow soybeans (Glycine max cv. Merit). Isoflavones were predominant in yellow soybeans, whereas they were completely absent in the green seeds on which flavanones were predominant. In order to enhance their health benefits, both types of bean were subjected to technological processes, such as soaking and fermentation. Soaking increased malonyl glucoside isoflavone extraction in yellow beans and produced an increase in apigenin derivatives in the green beans. Lactobacillus plantarum CECT 748 T fermentation produced an increase in the bioactivity of both beans since a conversion of glycosylated isoflavones into bioactive aglycones and an increase of the bioactive vitexin was observed in yellow and green beans, respectively. In spite of potential consumer confusion, since soybean and “green soybean” are different legumes, the health benefits of both beans were enhanced by lactic fermentation.