Showing papers on "Isoflavones published in 2014"
TL;DR: Although soy isoflavone-induced growth arrest and apoptosis of PCa cells are plausible mechanisms, other chemo protective mechanisms are also worthy of consideration, including antioxidant defense, DNA repair, inhibition of angiogenesis and metastasis, potentiation of radio- and chemotherapeutic agents, and antagonism of estrogen- and androgen-mediated signaling pathways.
214 citations
TL;DR: The clinical and epidemiologic data indicate that adding soy foods to the diet can contribute to the health of postmenopausal women.
140 citations
TL;DR: In this article, the authors proposed a mechanism of action based on five pillars/principles for phytoestrogens in terms of downregulation of pro-inflammatory cytokines, such as COX-2 and iNOS.
103 citations
TL;DR: Gene expression associated with soy intake and high plasma genistein defines a signature characterized by overexpression of FGFR2 and genes that drive cell cycle and proliferation pathways.
Abstract: Results Plasma isoflavones rose in the soy group (two-sided Wilcoxon rank-sum test, P 2-fold) of cell cycle transcripts, including those that promote cell proliferation, such as FGFR2, E2F5, BUB1, CCNB2, MYBL2, CDK1, and CDC20 (P < .01). Soy intake did not result in statistically significant changes in Ki67 or Cas3. Conclusions Gene expression associated with soy intake and high plasma genistein defines a signature characterized by overexpression of FGFR2 and genes that drive cell cycle and proliferation pathways. These findings raise the concerns that in a subset of women soy could adversely affect gene expression in breast cancer.
99 citations
TL;DR: Isoflavone supplementation enhances antioxidant action with attenuation of exercise-induced oxidative stress, as measured by decreases in TBARS, and inhibits body fat accumulation and plasma TG increase.
Abstract: BACKGROUND/OBJECTIVES: Isoflavones are widely believed to be beneficial to human health, in relation to their antioxidant potentials. Exercise can cause an imbalance between reactive oxygen species (ROS) and antioxidants. This study was conducted in order to investigate the ability of isoflavones in amelioration of oxidative stress induced by exercise. MATERIALS/METHODS: Male Sprague-Dawley rats were assigned to one of four groups: isoflavone-free with no exercise (CON-sd), isoflavone-free with exercise (CON-ex), isoflavone-supplemented with no exercise (ISF-sd), and isoflavone-supplemented with exercise (ISF-ex). Animals exercised on the treadmill for 30 minutes per day, five days per week. TBARS as a marker of oxidative stress and antioxidant enzyme activity, including SOD, GSH-px, and catalase were determined in liver tissue. Serum lipid profile was also examined. RESULTS: A significant effect of isoflavone alone was observed on abdominal fat pad mass. ISF-ex had significantly less abdominal fat pad than CON-ex. Both exercise and isoflavone treatment had significant effects on lowering plasma triglyceride (TG), thus, the ISF-ex group had a significantly lower TG level than the CON-sd group, by 30.9%. However, no differences were observed in plasma cholesterol, HDL-C, and cholesterol/HDL-C ratio. Exercise, isoflavone, and exercise-isoflavone interaction effects were significant on thiobarbituric acid reactive substances (TBARS) (P = 0.001, 0.002, and 0.005, respectively). The CON-ex group showed a higher TBARS level than the other three groups. By contrast, in the ISF-ex group, TBARS was restored to the level of the ISF-sd or CON-sd group. Isoflavone had a significant effect on superoxide dismutase (SOD) (P = 0.022) and catalase activities (P = 0.049). Significantly higher SOD and catalase activities were observed in ISF-ex than CON-ex. SOD and catalase activities showed an inverse pattern of TBARS. Taken together, isoflavones increased the activities of SOD and catalase with concomitant decreases in TBARS, indicative of decreased oxidative stress. CONCLUSIONS: Isoflavone supplementation enhances antioxidant action with attenuation of exercise-induced oxidative stress, as measured by decreases in TBARS, and inhibits body fat accumulation and plasma TG increase. Antioxidative effects ascribed to isoflavones may be partially exerted via enhancement of antioxidant enzyme activities.
99 citations
TL;DR: This review provides an overview of chemistry, analytical techniques, functions including biological mechanisms, and effects of isoflavones, on the basis of the available meta-analysis and review articles and some original articles, on health and cancer.
Abstract: Isoflavones are phytoestrogens and natural plant compounds which are similar to 17-β-estradiol in chemical structure. It is known that they can act as estrogen agonists or antagonists, depending on endocrine estrogenic levels, but actions of isoflavones are rather complex due to large number of variables such as chemical structures and mechanisms. Some hypotheses on biological mechanisms have not satisfactorily been confirmed to date and human epidemiological and experimental studies have been relatively limited. Nevertheless, isoflavones and isoflavone rich foods have become a focus onf interest due to positive health benefits on many diseases, especially prevention of hormone-related cancers, cardiovascular disease, osteoporosis, and adverse postmenopausal symptoms, and improvement of physiological condition such as maintaining cognitive function. This review provides an overview of chemistry, analytical techniques (focused on human biospecimens), functions including biological mechanisms, and effects of isoflavones, on the basis of the available meta-analysis and review articles and some original articles, on health and cancer.
95 citations
TL;DR: This is the first in vivo study using pyrosequencing to characterize significant differences in fecal community structure and composition in postmenopausal women after a week of soy diet-supplementation, and relate these changes to differences in soy is oflavones and isoflavone metabolites.
Abstract: Soy isoflavones and their metabolism by intestinal microbiota have gained attention because of potential health benefits, such as the alleviation of estrogen/hormone-related conditions in postmenopausal women, associated with some of these compounds However, overall changes in gut bacterial community structure and composition in response to addition of soy isoflavones to diets and their association with excreted isoflavone metabolites in postmenopausal women has not been studied The aim of this study was to determine fecal bacterial community changes in 17 postmenopausal women after a week of diet supplementation with soy bars containing isoflavones, and to determine correlations between microbial community changes and excreted isoflavone metabolites Using DGGE profiles of PCR amplified 16S rRNA genes (V3 region) to compare microbial communities in fecal samples collected one week before and one week during soy supplementation revealed significant differences (ANOSIM p<003) before and after soy supplementation in all subjects However, between subjects comparisons showed high inter-individual variation that resulted in clustering of profiles by subjects Urinary excretion of isoflavone (daidzein) metabolites indicated four subjects were equol producers and all subjects produced O-desmethylangolensin (ODMA) Comparison of relative proportions of 16S rRNA genes from 454 pyrosequencing of the last fecal samples of each treatment session revealed significant increases in average proportions of Bifidobacterium after soy consumption, and Bifidobacterium and Eubacterium were significantly greater in equol vs non-S-(-)equol producers This is the first in vivo study using pyrosequencing to characterize significant differences in fecal community structure and composition in postmenopausal women after a week of soy diet-supplementation, and relate these changes to differences in soy isoflavones and isoflavone metabolites
86 citations
TL;DR: The results establish an efficient strategy for successful pathway engineering of isoflavones and other flavonoids in crop plants and provide a direct evidence of improved osteoprotective effect of transgenic plant extract.
Abstract: Isoflavones, a group of flavonoids, restricted almost exclusively to family Leguminosae are known to exhibit anticancerous and anti-osteoporotic activities in animal systems and have been a target for metabolic engineering in commonly consumed food crops. Earlier efforts based on the expression of legume isoflavone synthase (IFS) genes in nonlegume plant species led to the limited success in terms of isoflavone content in transgenic tissue due to the limitation of substrate for IFS enzyme. In this work to overcome this limitation, the activation of multiple genes of flavonoid pathway using Arabidopsis transcription factor AtMYB12 has been carried out. We developed transgenic tobacco lines constitutively co-expressing AtMYB12 and GmIFS1 (soybean IFS) genes or independently and carried out their phytochemical and molecular analyses. The leaves of co-expressing transgenic lines were found to have elevated flavonol content along with the accumulation of substantial amount of genistein glycoconjugates being at the highest levels that could be engineered in tobacco leaves till date. Oestrogen-deficient (ovariectomized, Ovx) mice fed with leaf extract from transgenic plant co-expressing AtMYB12 and GmIFS1 but not wild-type extract exhibited significant conservation of trabecular microarchitecture, reduced osteoclast number and expression of osteoclastogenic genes, higher total serum antioxidant levels and increased uterine oestrogenicity compared with Ovx mice treated with vehicle (control). The skeletal effect of the transgenic extract was comparable to oestrogen-treated Ovx mice. Together, our results establish an efficient strategy for successful pathway engineering of isoflavones and other flavonoids in crop plants and provide a direct evidence of improved osteoprotective effect of transgenic plant extract.
76 citations
TL;DR: The antioxidant activity and cytotoxicity of O‑DMA, equol, daidzein and daidzin was investigated and their effects on HepG2 human hepatocelluar carcinoma cells were compared, suggesting that O‐DMA and equol possess greater antioxidant properties compared with daidzesin and may be beneficial for human health.
Abstract: Daidzein and its glycoside form daidzin, are known to have potential health benefits and are metabolized to O‑desmethylangolensin (O‑DMA) and equol following consumption. In the current study, the antioxidant activity and cytotoxicity of O‑DMA, equol, daidzein and daidzin was investigated and their effects on HepG2 human hepatocelluar carcinoma cells were compared. For cytotoxicity assays, lactose dehydrogenase (LDH) release and 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide‑based cell viability, cells were exposed to various concentrations of each compound (5‑200 µM) for 24, 48 or 72 h. O‑DMA and equol did not affect LDH release, but higher concentrations (<75 µM) showed inhibition of cell growth. By contrast, daidzein and daidzin (200 µM) increased LDH release and cell growth. All compounds stimulated catalase and total superoxide dismutase (SOD) (CuZn‑ and Mn‑SOD) activity, and mRNA and protein expression. This phenomenon was most pronounced for O‑DMA and equol, as their effects were similar. These data suggested that O‑DMA and equol possess greater antioxidant properties compared with daidzein and may, thus, be beneficial for human health.
75 citations
TL;DR: Isoflavone trials yielded significant reductions on hot flashes and co-occurring symptoms during the menopausal transition and postmenopause, but studies require replication with larger sample sizes and attention to measurement of outcomes.
59 citations
TL;DR: Although some women might experience a reduction in the frequency or severity of hot flashes, most studies point towards the lack of effectiveness of isoflavones derived from soy or red clover, even in large doses, in the prevention ofhot flashes and menopausal bone loss.
TL;DR: It is demonstrated that coexposure to BPA and genistein, or SF, results in increased functional and transcriptional estrogenic effects, and may contribute to estrogen-linked diseases, including breast cancer.
TL;DR: An overview of data established that chemical structures and concentrations modulate phytoestrogens effects: at the micromolar level, isoflavones activate ERα-mediated transcription and breast cancer cell proliferation while flavones fail to induce any significant promoting effects; at higher doses, both classes of compounds may display an antitumor activity.
TL;DR: The in vivo fermentation of the isoflavonoids by applying engineered E. coli BL21(DE3)/ΔpgiΔzwfΔushA overexpressing phosphoglucomutase (pgm) and glucose 1-phosphate uridyltransferase (galU), along with YjiC, found more than 60% average conversion of 200 μM of supplemented is oflavonoid glucosides, without any additional UDP-α
Abstract: A glycosyltransferase, YjiC, from Bacillus licheniformis has been used for the modification of the commercially available isoflavonoids genistein, daidzein, biochanin A and formononetin. The in vitro glycosylation reaction, using UDP-α-D-glucose as a donor for the glucose moiety and aforementioned four acceptor molecules, showed the prominent glycosylation at 4' and 7 hydroxyl groups, but not at the 5(th) hydroxyl group of the A-ring, resulting in the production of genistein 4'-O-β-D-glucoside, genistein 7-O-β-D-glucoside (genistin), genistein 4',7-O-β-D-diglucoside, biochanin A-7-O-β-D-glucoside (sissotrin), daidzein 4'-O-β-D-glucoside, daidzein 7-O-β-D-glucoside (daidzin), daidzein 4', 7-O-β-D-diglucoside, and formononetin 7-O-β-D-glucoside (ononin). The structures of all the products were elucidated using high performance liquid chromatography-photo diode array and high resolution quadrupole time-of-flight electrospray ionization mass spectrometry (HR QTOFESI/MS) analysis, and were compared with commercially available standard compounds. Significantly higher bioconversion rates of all four isoflavonoids was observed in both in vitro as well as in vivo bioconversion reactions. The in vivo fermentation of the isoflavonoids by applying engineered E. coli BL21(DE3)/ΔpgiΔzwfΔushA overexpressing phosphoglucomutase (pgm) and glucose 1-phosphate uridyltransferase (galU), along with YjiC, found more than 60% average conversion of 200 μM of supplemented isoflavonoids, without any additional UDP-α-D-glucose added in fermentation medium, which could be very beneficial to large scale industrial production of isoflavonoid glucosides.
TL;DR: In obese mice, daidzein inhibited hypertrophy in fat cell size and improved insulin sensitivity, concomitant with upregulation of PPARγ in fat tissue, thereby improving the adverse effects of adipose inflammation, such as insulin resistance, in obesity.
Abstract: cope
Daidzein was recently reported to act like an activator of peroxisome proliferator-activated receptor γ (PPARγ) thereby enhancing differentiation of adipocytes. Although PPARγ plays a role in adipokine expression, it has not been well researched whether daidzein affects expression of adipokines. This study aimed to clarify the effects of daidzein on proinflammatory adipokines and adipose inflammation causing insulin resistance in obesity.
Methods and results
3T3-L1 adipocytes were treated with daidzein or genistein. Diet-induced obese C57BL/6J mice were fed high-fat high-sucrose diets with daidzein (1.0 g/kg chow) for 12 wk. The results showed that both isoflavones, especially daidzein, stimulated adipogenic differentiation in 3T3-L1 adipocytes with the activation of PPARγ. Daidzein also increased adiponectin expression and decreased MCP-1 expression with the consistent regulation of their secretion. In obese mice, daidzein inhibited hypertrophy in fat cell size and improved insulin sensitivity, concomitant with upregulation of PPARγ in fat tissue. Decreased expression of MCP-1 and TNF-α, and increased expression of adiponectin were also observed in adipose tissue of daidzein-fed mice. Additionally, daidzein administration significantly inhibited macrophage accumulation in adipose tissue.
Conclusion
Daidzein regulates adipokine expression through the PPARγ, thereby improving the adverse effects of adipose inflammation, such as insulin resistance, in obesity.
TL;DR: It is demonstrated that isoflavone aglycones and is oflavone conjugates are induced in soybean leaves, not only by pathogens as previously demonstrated, but also by foliar insect herbivory.
Abstract: In response to attack by bacterial pathogens, soybean (Gylcine max) leaves accumulate isoflavone aglucones, isoflavone glucosides, and glyceollins. In contrast to pathogens, the dynamics of related insect-inducible metabolites in soybean leaves remain poorly understood. In this study, we analyzed the biochemical responses of soybean leaves to Spodoptera litura (Lepidoptera: Noctuidae) herbivory and also S. litura gut contents, which contain oral secretion elicitors. Following S. litura herbivory, soybean leaves displayed an induced accumulation of the flavone and isoflavone aglycones 4’,7-dihyroxyflavone, daidzein, and formononetin, and also the isoflavone glucoside daidzin. Interestingly, foliar application of S. litura oral secretions also elicited the accumulation of isoflavone aglycones (daidzein and formononetin), isoflavone 7-O-glucosides (daidzin, ononin), and isoflavone 7-O-(6’-O-malonyl-β-glucosides) (malonyldaidzin, malonylononin). Consistent with the up-regulation of the isoflavonoid biosynthetic pathway, folair phenylalanine levels also increased following oral secretion treatment. To establish that these metabolitic changes were the result of de novo biosynthesis, we demonstrated that labeled (13C9) phenylalanine was incorporated into the isoflavone aglucones. These results are consistent with the presence of soybean defense elicitors in S. litura oral secretions. We demonstrate that isoflavone aglycones and isoflavone conjugates are induced in soybean leaves, not only by pathogens as previously demonstrated, but also by foliar insect herbivory.
TL;DR: Six-month supplementation of daidzein significantly decreased TGs and uric acid, and may be effective to improve cardiovascular risk factors, especially in adults with the GA genotype of ESR-β RsaI.
Abstract: Daidzein (one of the major isoflavones) can be metabolized to equol in certain individuals. The effects of isoflavones alone and equol status on lipid profiles are still controversial. To evaluate the 6-mo effects of daidzein on cardiovascular risk factors in hypercholesterolemic individuals and the interactions of these effects with equol status and estrogen receptor (ESR) genotypes, we conducted a randomized, double-blind, placebo-controlled trial consisting of 210 hypercholesterolemic adults (40-65 y old). The participants were randomly assigned (177 completed) to consume placebo, 40 mg daidzein (DAI40), or 80 mg daidzein (DAI80) daily for 6 mo. Daidzein decreased serum triglycerides (TGs) by 0.15 ± 0.62 mmol/L (mean ± SD) and 0.24 ± 0.61 mmol/L and decreased serum uric acid by 23 ± 47 μmol/L and 29 ± 44 μmol/L in the DAI40 and DAI80 groups, respectively. These reductions in the DAI40 and DAI80 groups were greater than those in the placebo group (P < 0.05). Other blood lipids, glucose, insulin, or glycated hemoglobin did not significantly change after daidzein treatment. No dose-dependent effects of daidzein were found. The reduction of TGs was influenced by the ESR genotype, with a greater effect observed in participants with the GA genotype compared with those with the GG genotype of ESR-β RsaI. These effects were not influenced by equol status. Six-month supplementation of daidzein significantly decreased TGs and uric acid. ESR-β RsaI genotype, not equol status, influenced daidzein's effects on TGs. Daidzein consumption may be effective to improve cardiovascular risk factors, especially in adults with the GA genotype of ESR-β RsaI. This trial was registered at the Chinese clinical trial registry as ChiCTR-TRC-10001048.
TL;DR: In vitro dissolution results support the use of a buccal formulation to potentially improve its bioavailability in antichlamydial or other pharmaceutical applications, and biochanin A is a potent inhibitor of Chlamydia spp.
Abstract: Given the established role of Chlamydia spp. as causative agents of both acute and chronic diseases, search for new antimicrobial agents against these intracellular bacteria is required to promote human health. Isoflavones are naturally occurring phytoestrogens, antioxidants and efflux pump inhibitors, but their therapeutic use is limited by poor water-solubility and intense first-pass metabolism. Here, we report on effects of isoflavones against C. pneumoniae and C. trachomatis and describe buccal permeability and initial formulation development for biochanin A. Biochanin A was the most potent Chlamydia growth inhibitor among the studied isoflavones, with an IC50 = 12 µM on C. pneumoniae inclusion counts and 6.5 µM on infectious progeny production, both determined by immunofluorescent staining of infected epithelial cell cultures. Encouraged by the permeation of biochanin A across porcine buccal mucosa without detectable metabolism, oromucosal film formulations were designed and prepared by a solvent casting method. The film formulations showed improved dissolution rate of biochanin A compared to powder or a physical mixture, presumably due to the solubilizing effect of hydrophilic additives and presence of biochanin A in amorphous state. In summary, biochanin A is a potent inhibitor of Chlamydia spp., and the in vitro dissolution results support the use of a buccal formulation to potentially improve its bioavailability in antichlamydial or other pharmaceutical applications.
TL;DR: This review primarily envisages the different mechanisms involved in the therapeutic effects of soybean components as well as their contribution toward the reduction of different diseases.
Abstract: Soybeans contain nutritional and medicinal properties. It is a rich source of quality proteins, phytosterols, fibers, and other biologically active compounds, notably daidzein and genistein. Soybeans provide health benefits due to their functional ingredients such as proteins, polysaccharides, and isoflavones. These functional ingredients play a vital role in the reduction of different types of cancer, cardiovascular diseases, postmenopausal problems, diabetes, and some neurodegenerative disorders. This review primarily envisages the different mechanisms involved in the therapeutic effects of soybean components as well as their contribution toward the reduction of different diseases.
TL;DR: Both biochanin A and prunetin were identified as potent reducers of NF-κB and ERK activation, zonula occludens 1 tyrosine phosphorylation, and metalloproteinase-mediated shedding activity, which may account for the barrier-improving ability of these isoflavones.
TL;DR: The results suggest that water may be used as a green alternative for separation of isoflavones from okara and there was no significant difference between is oflavone extraction in water and in 70% aqueous ethanol.
TL;DR: Effects of isoflavones on adipose tissue gene expression were influenced by supplement composition and equol-producing phenotype, whereas estrogen-responsive effects were lacking, whereas both supplements induced anti-inflammatory gene expression in equol producers.
TL;DR: In this article, the conditions for the soaking process of soybeans for maximal conversion of β-glucoside isoflavones into aglycones using response surface methodology were investigated.
Abstract: The objective of this work was to optimise the conditions for the soaking process of soybean for maximal conversion of β-glucoside isoflavones into aglycones using response surface methodology. The investigated variables were the time (3, 4, 6, 8, and 9 h) and temperature (41, 45, 55, 65, and 69 °C ± 1 °C) for the soaking of soybean in 1:1.5 (g:g) ratio with a buffer solution pH 6. The maximum aglycones content (1.22 μmol g−1) in soaked soybeans was estimated and validated at 55 °C ± 1 °C and 6 h of soaking. In this condition, the hydrothermally treated soybean grains showed a minimum content of β-glucoside isoflavones and low β-glucosidase activity. A 30% reduction in total isoflavones content of the system was estimated at 69 °C ± 1 °C not depending on the soaking time, attributed to the thermal instability of malonylglucosides. This work may contribute to the preparation of soy products rich in aglycones from hydrothermally treated soybean.
TL;DR: Flow cytometric analysis of MCF-7 proliferation is a suitable bioassay for the estrogenicity of RCL extracts, thus expanding the characterization of individual batches beyond assessment of chemical composition and contributing to improved standardization of quality and activity.
TL;DR: In this article, the isoflavones composition of different extracts of Medicago species (M. minima, M. scutelata, M. truncatula), M. rigidula, M segitalis and M. sativa ) were determined by high performance liquid chromatography (HPLC/DAD).
TL;DR: In this paper, the effects of soybean soaking on grain properties and isoflavone loss were investigated in order to find suitable conditions for this step of the soybean processing, and a moisture content of 120% was achieved by soaking the soybeans at 55°C and 70°C for 3 and 2 hours respectively.
Abstract: The aim of this study was to investigate the effects of soybean soaking on grain properties and isoflavone loss in order to find suitable conditions for this step of soybean processing. A moisture content of 120% (dry basis) was achieved by soaking the soybeans at 55 °C and 70 °C for 3 and 2 h, respectively. Soybeans soaked at temperatures above 25 °C showed no significant difference (p > 0.05) in hardness after 1 h of soaking. The contents of total isoflavones and soluble proteins were better preserved at soaking temperatures of 25 °C and 40 °C. The β-glucosidase activity and contents of aglycone and β-glucoside isoflavones were closely related. Soybeans soaked at 55 °C for 5 h had a 6-fold higher aglycone isoflavone content than did whole soybeans (81.4 μg aglycones g−1) without considerable impairment of the aforementioned characteristics; soaking under this condition is therefore recommended before subsequent processing. This work helps to estimate the loss in soluble protein content and the loss and degradation of isoflavones during soybean soaking at different temperatures.
TL;DR: The present study provides the first clarification of the detailed antioxidant SARs of isoflavonoid subgroups based on the structural diversity of the is oflavonoids in D. parviflora.
Abstract: The antioxidant activities of 24 isoflavonoids that were previously isolated as pure compounds from Dalbergia parviflora were evaluated using three different in vitro antioxidant-based assay systems: xanthine/xanthine oxidase (X/XO), ORAC, and DPPH. The isolates consisted of three subgroups, namely isoflavones, isoflavanones, and isoflavans, each of which appeared to have diversified substituents, and were thus ideal for the study of their structure-activity relationships (SARs). The SAR analysis was performed using the results obtained from both the inter-subgroup isoflavonoids with the same substitution pattern and the intra-subgroup compounds with different substitution patterns. The inter-subgroup comparison showed that the isoflavones exhibited the highest antioxidant activities based on all three assays. The intra-subgroup analysis showed that the additional presence of an OH group in Ring B at either R3′ or R5′ from the basic common structure of the R7-OH of Ring A and the R4′-OH (or -OMe) of Ring B greatly increased the antioxidant activities of all of the isoflavonoid subgroups and that other positions of OH and OMe substitutions exerted different effects on the activities depending on the subgroup and assay type. Therefore, based on the structural diversity of the isoflavonoids in D. parviflora, the present study provides the first clarification of the detailed antioxidant SARs of isoflavonoids.
TL;DR: The levels of equol and its conjugates in plasma for a 24 h period resulting from oral administration of dietary daidzein and racemic equol in ovariectomized Sprague–Dawley rats were assessed to assess the changes in equol metabolism.
Abstract: Recent findings indicate that soy isoflavones and their metabolites may play a role in mitigating postmenopausal bone loss. Equol, a metabolite of the soy isoflavone daidzein produced by intestinal bacteria, has shown some potential, but only 30–50% of the U.S. population is capable of converting dietary daidzein to equol. There are limited data on the pharmacokinetics of dietary racemic equol and its metabolites. This study was conducted to assess the levels of equol and its conjugates in plasma for a 24 h period resulting from oral administration of dietary daidzein and racemic equol in ovariectomized Sprague–Dawley rats. Plasma samples were analyzed for conjugated and free forms of equol using LC-MS/MS. The maximum plasma concentration (Cmax) and time to reach it (tmax) for total equol (conjugated and unconjugated) were 8815 ± 2988 nmol/L and 2.17 ± 2.91 h and 3682 ± 2675 nmol/L and 20.67 ± 4.67 h, for dietary equol and daidzein, respectively. Although the majority of equol metabolites present were glu...
TL;DR: The results indicate that, when flavonoids and isoflavonoids were ingested together, the metabolic conversions in the small intestine and/or the liver could be altered, resulting in the variation of the postprandial profiles of the plasma metabolites.
Abstract: Scope
The effect of food combination on metabolic profile in postprandial plasma has hardly been reported. We investigated the absorption and metabolism of quercetin and soy isoflavones in humans after combination meal consumption.
Methods and results
Five healthy volunteers ingested sauteed onion and tofu, and the plasma metabolites of quercetin and isoflavones were analyzed. Quercetin and genistein were incubated with human intestinal Caco-2 cells and human hepatoma HepG2 cells to further analyze the influence of simultaneous supply to the small intestine and the liver. Glucuronosyl conjugates of quercetin and methylated quercetin were the major plasma metabolites in the case of onion intake. Plasma metabolites with the single serving of tofu were both glucuronide and sulfate metabolites of isoflavones. Interestingly, quercetin sulfate was only detected after the combined intake of sauteed onion and tofu, accompanied with a decrease in sulfated isoflavones. Besides, quercetin was shown as the preferential substance for phase II enzymes over genistein in both Caco-2 and HepG2 cells.
Conclusion
These results indicate that, when flavonoids and isoflavonoids were ingested together, the metabolic conversions in the small intestine and/or the liver could be altered, resulting in the variation of the postprandial profiles of the plasma metabolites.
TL;DR: In this article, the authors examined cross-talk interactions of soluble sugars (sucrose, glucose and fructose) and infection caused by Fusarium oxysporum f.lupini on the synthesis of genistein in embryo axes of Lupinus luteus L.cv.sp. Juno.
Abstract: The aim of the study was to examine cross-talk interactions of soluble sugars (sucrose, glucose and fructose) and infection caused by Fusarium oxysporum f.sp. lupini on the synthesis of genistein in embryo axes of Lupinus luteus L.cv. Juno. Genistein is a free aglycone, highly reactive and with the potential to inhibit fungal infection and development of plant diseases. As signal molecules, sugars strongly stimulated accumulation of isoflavones, including genistein, and the expression of the isoflavonoid biosynthetic genes. Infection significantly enhanced the synthesis of genistein and other isoflavone aglycones in cells of embryo axes of yellow lupine with high endogenous sugar levels. The activity of β-glucosidase, the enzyme that releases free aglycones from their glucoside bindings, was higher in the infected tissues than in the control ones. At the same time, a very strong generation of the superoxide anion radical was observed in tissues with high sugar contents already in the initial stage of infection. During later stages after inoculation, a strong generation of semiquinone radicals was observed, which level was relatively higher in tissues deficient in sugars than in those with high sugar levels. Observations of actin and tubulin cytoskeletons in cells of infected embryo axes cultured on the medium with sucrose, as well as the medium without sugar, showed significant differences in their organization.