Higher Isoflavone Concentrations Research Articles

European soybean to benefit people and the environment

Europe imports large amounts of soybean that are predominantly used for livestock feed, mainly sourced from Brazil, USA and Argentina. In addition, the demand for GM-free soybean for human consumption is project to increase. Soybean has higher protein quality and digestibility than other legumes, along with high concentrations of isoflavones, phytosterols and minerals that enhance the nutritional value as a human food ingredient. Here, we examine the potential to increase soybean production across Europe for livestock feed and direct human consumption, and review possible effects on the environment and human health. Simulations and field data indicate rainfed soybean yields of 3.1 ± 1.2 t ha−1 from southern UK through to southern Europe (compared to a 3.5 t ha−1 average from North America). Drought-prone southern regions and cooler northern regions require breeding to incorporate stress-tolerance traits. Literature synthesized in this work evidenced soybean properties important to human nutrition, health, and traits related to food processing compared to alternative protein sources. While acknowledging the uncertainties inherent in any modelling exercise, our findings suggest that further integrating soybean into European agriculture could reduce GHG emissions by 37–291 Mt CO2e year−1 and fertiliser N use by 0.6–1.2 Mt year−1, concurrently improving human health and nutrition.

Fermented soy beverages as vehicle of probiotic lactobacilli strains and source of bioactive isoflavones: A potential double functional effect

Soy beverages can be a source of bioactive isoflavones, with potential human health benefits. In this work, the suitability of three Lacticaseibacillus and three Bifidobacterium probiotic strains as functional starters for soy beverage fermentation were evaluated, alongside with the effect of refrigerated storage on the viability of the strains and the isoflavone composition of the fermented beverages. The three bifidobacteria strains suffered a decrease in their viability during refrigeration and only Bifidobacterium breve INIA P734 produced high concentrations of bioactive isoflavones. Meanwhile, L. rhamnosus GG and L. rhamnosus INIA P344 produced high levels of aglycones and, with L. paracasei INIA P272, maintained their viability during the refrigeration period, constituting promising starters to obtain functional soy beverages that could gather the benefits of the bioactive isoflavone aglycones and the probiotic strains. Moreover, the three lactobacilli caused an increase in the antioxidant capacity of the fermented beverages, which was maintained over the refrigerated storage.

Formation and physical characterization of soy protein-isoflavone dispersions and emulsions

Proteins stabilize emulsions by adsorbing at the interface to prevent the natural tendency of droplet coalescence. Polyphenols (plant-derived secondary metabolites) are capable of complexing with proteins through structural interactions. Certain polyphenols have shown influence on interfacial properties of proteins, yet isoflavones specifically have not been widely investigated. Thus, the objective of this research was to study the effect of isoflavones on protein-stabilized oil-in-water emulsions. Soy protein fractions, assessed via SDS-PAGE and bicinchoninic acid assay, contained primarily β-conglycinin (7S) and glycinin (11S). Notable isoflavones identified from HPLC analysis were daidzin, genistin, and glycitin. Physical characteristics (size, zeta potential, polydispersity index, and wettability) of soy protein isolate-isoflavone (SPI–I) dispersions and emulsion droplets were measured with a Zetasizer Nano ZS and goniometer. Isoflavone addition significantly increased the contact angle of sessile drops towards neutral wettability. Heating appeared to significantly improve colloidal stability and emulsion droplets formed with heated SPI-I dispersions sustained size (∼200–245 nm) and zeta potential (∼-30-35 mV) over 7 days, with higher concentrations of isoflavones being generally correlated with smaller emulsion droplets. Collectively, these findings indicate that isoflavone addition improved emulsion stability compared to the control without isoflavones and that they can contribute to colloidal stability of food products.

Comparative Transcriptome Analysis to Identify Candidate Genes Related to Chlorogenic Acid and Flavonoids Biosynthesis in Iridaceae

Iris (Iridaceae) is one of the most widely admired ornamental plants. It has been used mainly in medicine due to the high concentration of chlorogenic acid (CGA), flavonoids, isoflavones, lignans, and other compounds in its rhizomes. In iris, the gene functions related to CGA and flavonoids biosynthesis are still unclear. In this study, we compared the I. germanica rhizome with a high accumulation level of CGA but a low accumulation level of flavonoids, and the I. pallida rhizome with a low accumulation level of CGA but a high accumulation level of flavonoids at the transcriptome and metabolome levels. A total of 761 metabolites were detected, including 202 flavonoids and 106 phenolic acids based on metabolome profiling. In total, 135 flavonoids were highly accumulated in I. pallida, including three flavanols, 51 flavonoids, 12 flavonoid carbonosides, 31 flavonols, and 21 isoflavones. Based on single-molecule long-read sequencing technology, 94,461 transcripts were identified in iris. Expression analysis indicated that the high accumulation level of C4H and 4CL in I. germanica were essential for CGA accumulation, while CHS, DFR, ANS, ANR, LAR, and 3GT were essential for flavonoids biosynthesis in I. pallida. Many transcription factors such as transcript_83288 (MYB), transcript_57970 (WRKY), and transcript_77465 (WRKY) act as regulators, playing important roles in these biological processes. Our findings provide new insights into the molecular mechanisms associated with the biosynthesis and regulation of flavonoids and CGA in the iris rhizome, and highlight the usefulness of an integrated approach for understanding this process.

Genome wide association study to detect genetic regions related to isoflavone content in a mutant soybean population derived from radiation breeding.

Isoflavones are major secondary metabolites that are exclusively produced by legumes, including soybean. Soy isoflavones play important roles in human health as well as in the plant defense system. The isoflavone content is influenced by minor-effect quantitative trait loci, which interact with polygenetic and environmental factors. It has been difficult to clarify the regulation of isoflavone biosynthesis because of its complex heritability and the influence of external factors. Here, using a genotype-by-sequencing-based genome-wide association mapping study, 189 mutant soybean genotypes (the mutant diversity pool, MDP) were genotyped on the basis of 25,646 high-quality single nucleotide polymorphisms (SNPs) with minor allele frequency of >0.01 except for missing data. All the accessions were phenotyped by determining the contents of 12 isoflavones in the soybean seeds in two consecutive years (2020 and 2021). Then, quantitative trait nucleotides (QTNs) related to isoflavone contents were identified and validated using multi-locus GWAS models. A total of 112 and 46 QTNs related to isoflavone contents were detected by multiple MLM-based models in 2020 and 2021, respectively. Of these, 12 and 5 QTNs were related to more than two types of isoflavones in 2020 and 2021, respectively. Forty-four QTNs were detected within the 441-Kb physical interval surrounding Gm05:38940662. Of them, four QTNs (Gm05:38936166, Gm05:38936167, Gm05:38940662, and Gm05:38940717) were located at Glyma.05g206900 and Glyma.05g207000, which encode glutathione S-transferase THETA 1 (GmGSTT1), as determined from previous quantitative trait loci annotations and the literature. We detected substantial differences in the transcript levels of GmGSTT1 and two other core genes (IFS1 and IFS2) in the isoflavone biosynthetic pathway between the original cultivar and its mutant. The results of this study provide new information about the factors affecting isoflavone contents in soybean seeds and will be useful for breeding soybean lines with high and stable concentrations of isoflavones.

Effects of Soy Isoflavones, Resistant Starch and Antibiotics on Polycystic Ovary Syndrome (PCOS)-Like Features in Letrozole-Treated Rats.

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in reproductive-aged women. Recently, various dietary interventions have been used extensively as a novel therapy against PCOS. In the present study, we show that soy isoflavone metabolites and resistant starch, together with gut microbiota modulations, were successful in decreasing the severity of PCOS-like reproductive features while increasing the expression of gut barrier markers and butyric acid in the gut. In the letrozole-induced PCOS model rats, the intake of both 0.05% soy isoflavones and 11% resistant starch, even with letrozole treatment, reduced the severity of menstrual irregularity and polycystic ovaries with a high concentration of soy isoflavones and equol in plasma. Antibiotic cocktail treatment suppressed soy isoflavone metabolism in the gut and showed no considerable effects on reducing the PCOS-like symptoms. The mRNA expression level of occludin significantly increased with soy isoflavone and resistant starch combined treatment. Bacterial genera such as Blautia, Dorea and Clostridium were positively correlated with menstrual irregularity under resistant starch intake. Moreover, the concentration of butyric acid was elevated by resistant starch intake. In conclusion, we propose that both dietary interventions and gut microbiota modulations could be effectively used in reducing the severity of PCOS reproductive features.

FORMULATION OF SELECTED SOY PRODUCTS FOR WOMEN’S HEALTH

Soybean differs from other cereals and legumes by containing the highest amount of complete protein. Tofu, soy milk, soy meat are nonfermented products of soybean. Soy contains chemical compounds are unique because of its high concentration of isoflavones, a type of plant estrogen. Women entering the menopausal stage are recommended to consume soya bean because this plant estrogen would benefit them. The study aims to inculcate the consumption of soy products through standardized recipes. The popular soy milk product is Tofu. It is prepared by curdling fresh hot soy milk with a coagulant. On milling, soybean yielded a nutritious product called Soy flour, which is available in two types namely full-fat soy flour (FFSF) and defatted soy flour (DFSF). When the soybean oil is extracted, the by-product called Soy Chunks is produced. In current study, soy products namely Tofu, Defatted Soy Flour, and Soy Chunks were used to standardize few recipes by incorporating them in commonly consumed recipes or using them wholly. Further, for this, Tofu with pasta and sandwich, Chunks in kurma and nuggets, DFSF with besan omelette, and cakes were incorporated and standardized. Along with this, organoleptic evaluations were carried out for the developed products and were standardized. The nutritive values for DFSF and storage stability of standardized cakes were also carried out.

Metabolic profile of Lactobacillus paracasei subsp. paracasei CRL 207 in solid state fermentation using commercial soybean meal

Solid state fermentation (SSF) using soybean meal and a lactic culture was used to obtain value-added products. The metabolites produced from a Lactobacillus paracasei subsp. paracasei CRL 207 during SSF were studied in 9 conditions of moisture and temperature. The greatest effect was best correlated with substrate moisture and it was shown that lactic fermentation was not accompanied by a pH decreases with certain conditions. Sugar intake, organic acid production, free amino acids profile, and isoflavones conversion were also measured. These factors helped in selecting the optimal conditions of 65% moisture and 37 °C to obtain a product with high concentrations of bioactive isoflavones (40.6 mg/50 g of wet product), organic acids (143 μmol/g) and free amino acids (31 μg/ml). Optimized fermented soy paste could be used as a base for development of new functional vegetable products and also, as a carrier of a potential probiotic microorganism as alternatives to dairy products.

Abstract 2276: Effect modification by isoflavones on the association between salt intake and gastric cancer risk: A case-cohort study within the Korean multi-center cancer cohort

Abstract Backgrounds: Attenuation by genistein, an isoflavone abundant in soybean, of gastric carcinogenesis induced by sodium chloride was reported in an animal study. Up to date, role of isoflavone as an effect modifier on the association between salt intake and gastric cancer risk is not clearly established. Methods: We randomly selected 640 subcohort subjects without cancer history at enrollment from the Korean multi-center cancer cohort participants. Ninety-nine gastric cancer cases were identified from the inside (N=8) and the outside (N=91) of the subcohort after the 12.2 years of median follow-up time. To estimate individual’s salt intake, we measured 24-hour urinary sodium excretion from spot urine using the Tanaka’s equation. Three isoflavone plasma concentrations (Genistein, daidzein, and equol) of 167 subjects among case-cohort subjects had been measured using time-resolved fluoroimmunoassay. Cubic spline curve for gastric cancer risk according to urinary sodium level was used to define optimal cut-off points of urinary sodium excretion concentration. Weighted Cox proportional hazard regression was used to calculate hazard ratios (HRs) and their 95% confidence intervals (CIs). Stratified analysis by isoflavone level was conducted to assess effect modification by isoflavone on the association between salt intake and gastric cancer. Results: Gastric cancer risk in the high salt intake group (urinary sodium excretion ≥6,000mg/day) was significantly increased (HR, 1.69; 95% CI, 0.99-2.90) compared to the reference group (urinary sodium excretion 4500-5,999mg/day). Magnitudes of gastric cancer risk by high salt intake were more strengthened in the group with low plasma isoflavone concentrations (One or no genistein, diadzein or equol levels over the median concentrations) (HR, 6.92; 95% CI, 1.80-26.56). Contrary to the low isoflavone group, no significant differences in gastric cancer risk according to salt intake levels were found in the group with high isoflavone concentration. Conclusions: High salt intake is associated with gastric cancer risk, but this association can be attenuated by high concentration of isoflavones. We suggest that sufficient intake of soybean products, the rich sources of isoflavone, may give protection against gastric cancer in the population with high salt intake. Citation Format: Jieun Jang, Yunji Hwang, Choonghyun Ahn, Kwang-Pil Ko, Aesun Shin, Keun-Young Yoo, Sue K. Park. Effect modification by isoflavones on the association between salt intake and gastric cancer risk: A case-cohort study within the Korean multi-center cancer cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2276. doi:10.1158/1538-7445.AM2017-2276

Isoflavone Content in Subterranean Clover Germplasm from Sardinia.

Subterranean clover (Trifoliumsubterraneum) is an important pasture legume, and Sardinia is known as a major centre of diversification of this species. As other legumes, this clover produces biologically active flavonoids including the subclass of isoflavones that are natural phytoestrogens with positive health effects. Present sources of isoflavones for medical/nutraceutical treatments are red clover (Trifoliumpratense) and soybean (Glycinemax). This study assessed the content and composition of flavonoids in 14 subterranean clover genotypes from Sardinia, grown ex-situ in comparison with two red clover ecotypes, to acquire information on the potential of the species as an alternative source of isoflavones for possible exploitation. Twenty compounds were tentatively identified across the two clovers after HPLC and LC/ESI-MS analyses, including clovamide, four flavonols, and 15 isoflavones. Most compounds were present as glucosides or glucosyl malonates. Subterranean clover extracts mainly comprised of derivatives of the isoflavones genistein, biochanin A, and formononetin. Compared to red clover, subterranean clover had higher content of total isoflavones and lower concentration of total flavonols. The isoflavone concentration in subterranean clover was higher than literature data for soybean or red clover. The existing genotypic variation warrants the possibility of selecting varieties with high isoflavone concentration for nutraceutical or pharmaceutical purposes.

Impact of a soy drink on climacteric symptoms: an open-label, crossover, randomized clinical trial

Objectives: The objective of this study is to evaluate the effects of a soy drink with a high concentration of isoflavones (ViveSoy®) on climacteric symptoms.Methods: An open-label, controlled, crossover clinical trial was conducted in 147 peri- and postmenopausal women. Eligible women were recruited from 13 Spanish health centers and randomly assigned to one of the two sequence groups (control or ViveSoy®, 500 mL per day, 15 g of protein and 50 mg of isoflavones). Each intervention phase lasted for 12 weeks with a 6-week washout period. Changes on the Menopause Rating Scale and quality of life questionnaires, as well as lipid profile, cardiovascular risk and carbohydrate and bone metabolism were assessed. Statistical analysis was performed using a mixed-effects model.Results: A sample of 147 female volunteers was recruited of which 90 were evaluable. In both sequence groups, adherence to the intervention was high. Regular consumption of ViveSoy® reduced climacteric symptoms by 20.4% (p = 0.001) and symptoms in the urogenital domain by 21.3% (p < 0.05). It also improved health-related quality life by 18.1%, as per the MRS questionnaire (p <0.05).Conclusion: Regular consumption of ViveSoy® improves both the somatic and urogenital domain symptoms of menopause, as well as health-related quality of life in peri- and postmenopausal women.

High Vegetable Protein Diet is Associated with Low Lumbar Spine Bone Mineral Density in Amenorrheic Athletes

PURPOSE: We have reported that amenorrheic athletes (AA) have a higher intake of dietary fiber compared to eumenorrheic athletes (EA) and non-athletes (NA), which is negatively associated with lumbar BMD. High fiber diets are rich in vegetable proteins, and food rich in vegetable protein has high concentrations of phytic acid and isoflavones, and low concentrations of saturated fatty acids (SFA). Fiber and isoflavones are reported to have negative associations with serum estrogen. We hypothesized that a diet high in vegetable protein may contribute to low BMD in AA. METHODS: 4-day food records and serum samples were collected from 68 AA, 24 EA, and 26 NA 14–23 yo. Energy availability was calculated as (energy intake- energy expenditure)/ fat free mass. DXA was used to assess lumbar spine BMD. RESULTS: EA were younger than AA and NA (p=.04), and AA had lower BMI (p=.04). Exercise activity did not differ in AA and EA. There was no difference in energy availability among groups. Compared with EA and NA, AA had higher intake of fiber (AA=34.8±15.3; EA=22.5±11.7; NA=17.2±6.6g; p<.0001), phytic acid (AA=1276±621; EA=621±384; NA=700±370mg; p<.0001), and vegetable protein (AA=45.6±19.2; EA=31.9±12.9; NA=26.8±8.8g; p<.0001). Intake of isoflavones was higher in AA than NA (genistein: AA=7.4±10.1; EA=2.7±6.7; NA=1.4±4.2g; p=.003; daidzein: AA=5.9±8.0; EA=2.0±4.8; NA=1.0±2.9g; p=.0002). AA had a lower intake of % calories from SFA than NA (AA=8.6±2.6; EA=9.8±2.2; NA=10.6±2.6; p=.002). After controlling for menstrual status, calcium intake and serum vitamin D, spine Z-scores were associated inversely with vegetable protein (SE=−.34, p=.006), phytic acid (SE=−.32, p=.005), genistein (SE=−.29, p=.003), and daidzein (SE=−.28, p=.005) ; and positively with %SFA after also controlling for fiber (SE=.26,p=.02). CONCLUSIONS: We found a higher vegetable protein diet in AA than EA and C, associated inversely with spine Z-scores. Because phytic acid and dietary fiber decrease energy and mineral absorption, some AA may have adequate energy intake but be nutrient deficient. Furthermore, the ability of dietary fiber and isoflavones to decrease estrogen may affect BMD. Studies examining nutrients affecting bone metabolism and estrogen levels in female athletes are needed to develop optimal dietary recommendations.

Effect of soy isoflavones on the growth of human breast tumors: findings from preclinical studies.

Breast cancer is the most common cancer among women worldwide, and many women with breast cancer live more than 5 years after their diagnosis. Breast cancer patients and survivors have a greater interest in taking soy foods and isoflavone supplements. However, the effect of isoflavones on breast cancer remains controversial. Thus, it is critical to determine if and when isoflavones are beneficial or detrimental to breast cancer patients. According to the available preclinical data, high concentrations of isoflavones inhibit the proliferation of breast cancer cells, regardless of their estrogen receptor (ER) status. In comparison, genistein, a major isoflavone, has stimulated tumor growth at low concentrations and mitigated tamoxifen efficacy in ER-positive breast cancer. Studies have indicated that the relative levels of genistein and estrogen at the target site are important to determine the genistein effect on the ER-positive tumor growth. However, studies using ovariectomized mice and subcutaneous xenograft models might not truly reflect estrogen concentrations in human breast tumors. Moreover, it may be an oversimplification that isoflavones stimulate hormone-dependent tumor growth due to their potential estrogenic effect since studies also suggest nonestrogenic anticancer effects of isoflavones and ER-independent anticancer activity of tamoxifen. Therefore, the concentrations of isoflavones and estrogen in human breast tumors should be considered better in future preclinical studies and the parameters that can estimate those levels in breast tumors are required in human clinical/epidemiological investigation. In addition, it will be important to identify the molecular mechanisms that either inhibit or promote the growth of breast cancer cells by soy isoflavones, and use those molecules to evaluate the relevance of the preclinical findings to the human disease and to predict the health effects of isoflavones in human breast tumors.

β-GLUCOSIDASE ACTIVITY OF SOYBEAN (GLYCINE MAX) EMBRYONIC AXIS GERMINATED IN THE PRESENCE OR ABSENCE OF LIGHT

ABSTRACT The aim of this study was to investigate the β-glucosidase activity of radicles, hypocotyls, cotyledons and epicotyls of soybeans (Glycine max) grown in the presence and absence of light and to obtain an alternative source of β-glucosidase. Seeds were germinated in the presence and absence of light at various time points, and the radicles, epicotyls, hypocotyls and cotyledons were separated. The enzymatic activity in the epicotyls presented the highest activity at 144 h in the presence of light. Specifically, the enzymatic activity of the epicotyls was sixfold higher than that of radicles and 12-fold higher than that of cotyledons. Interestingly, the specific activity of hypocotyls and cotyledons was 4.02-fold and 5.17-fold lower than that of epicotyls after 144 h of germination under light. The high specific activity of light-germinated epicotyls suggested that the purity of β-glucosidase from epicotyls is greater than β-glucosidase obtained from other parts of the plant. PRACTICAL APPLICATIONS Isoflavones are beneficial to human health. Specifically, isoflavones and estrogen have similar positive effects on the symptoms of menopause and osteoporosis. Moreover, isoflavones possess antioxidant and antitumoral properties against certain cancers. In nature, the most common form of the isoflavone is the glycosylated form. Studies on the bioavailability of isoflavones indicate that these compounds behave similarly to estrogen in most biological systems and the aglycone forms are more bioavailable than their glycoside forms. β-glucosidase is produced from the metabolism of fungi, bacteria or soybeans, and is the only enzyme capable of hydrolyzing isoflavone glycosides to aglycones. Therefore, safe and effective methods for the synthesis of β-glucosidase must be developed to produce soy-based foods with high concentrations of aglycone isoflavones. Thus, the objective of the present study is to investigate the best conditions under which the greatest amount of β-glucosidase could be isolated from soybean.

Spatial distribution of isoflavones and isoflavone-related gene expression in high- and low-isoflavone soybean cultivars

Chen, H., Seguin, P., Jabaji, S. and Liu, W. 2011. Spatial distribution of isoflavones and isoflavone-related gene expression in high and low isoflavone soybean cultivars. Can. J. Plant Sci. 91: 697-705. Soybean contains high concentrations of isoflavones that have putative health-beneficial effects. A study was conducted to document the spatial distribution of isoflavones and the expression of 14 key genes and gene homologs encoding enzymes involved in isoflavone synthesis using quantitative reverse transcription (QRT)-PCR. Genes studied included phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI), chalcone reductase (CHR), and isoflavone synthase (IFS). Two cultivars were used, AC Proteina and AC Orford, high- and low-isoflavone cultivars, respectively. Plants were harvested at the seed filling stage (R5) and were separated into leaf, stem, root, flower, pod, and seed parts. The present study revealed that at the R5 stage the expression of 14 key genes and gene homologs ...

Spatial distribution of isoflavones and isoflavone-related gene expression in high- and low-isoflavone soybean cultivars

Chen, H., Seguin, P., Jabaji, S. and Liu, W. 2011. Spatial distribution of isoflavones and isoflavone-related gene expression in high and low isoflavone soybean cultivars. Can. J. Plant Sci. 91: 697–705. Soybean contains high concentrations of isoflavones that have putative health-beneficial effects. A study was conducted to document the spatial distribution of isoflavones and the expression of 14 key genes and gene homologs encoding enzymes involved in isoflavone synthesis using quantitative reverse transcription (QRT)-PCR. Genes studied included phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI), chalcone reductase (CHR), and isoflavone synthase (IFS). Two cultivars were used, AC Proteina and AC Orford, high- and low-isoflavone cultivars, respectively. Plants were harvested at the seed filling stage (R5) and were separated into leaf, stem, root, flower, pod, and seed parts. The present study revealed that at the R5 stage the expression of 14 key genes and gene homologs involved in isoflavone synthesis is observed in all plant parts, being, however, minimal in pods and seeds and greatest in leaves and roots. Gene expression data parallel isoflavone concentrations, which are also minimal in pods and seeds. In most cases, expression of all homologs of a given gene family was comparable in specific parts, the expression of homologs not being part-specific. Finally, gene expression differences between cultivars also paralleled differences observed in their isoflavone concentrations.

Inflammation-Related Signaling Pathways Implicating TGFβ are Revealed in the Expression Profiling of MCF7 Cell Treated with Fermented Soybean, Chungkookjang

Chungkookjang is a Korean fermented soybean containing microorganisms, proteinase, and diverse bioactive compounds, including a high concentration of isoflavones and peptides. Growth of breast cancer MCF7 cells decreased dependent on the concentration of fermented soybean extracts. The effect of fermented soybean on cellular gene expression was determined in a systematic manner comprehensively. DNA microarray analysis was performed using 25,804 probes. Ninety one genes whose expression levels were significantly changed were selected. TGFβI and Smad3 were upregulated. Downregulation of inflammation-related CSF2, CSF2RA, and CSF3 was found. Differential expression of chemokines CCL2, CCL3, CCL3L3, CXCL1, and CXCL2 were observed. Network analysis identified ERβ in the network. Based on the experimental results, taking fermented soybean might be helpful for preventing breast cancer by a mechanism activating TGFβ pathway and depressing inflammation.[Supplemental materials are available for this article. Go to the publisher's online edition of Nutrition and Cancer for the following free supplemental resources: Detailed table showing the full list of genes and their analysis details.]

Increase of isoflavones in soybean callus by Agrobacterium-mediated transformation

Plant secondary metabolites have always been a focus of study due to their important roles in human medicine and nutrition. We transferred the isoflavone synthase (IFS) gene into soybean [Glycine max (L.) Merr.] using the Agrobacterium-mediated transformation method in an attempt to produce transformed soybean plants which produced increased levels of the secondary metabolite, isoflavone. Although the trial to produce transgenic plant failed due to unestablished hygromycin selection, transformed callus cell lines were obtained. The induction rate and degree of callus were similar among the three cultivars tested, but light illumination positively influenced the frequency of callus formation, resulting in a callus induction rate of 74% for Kwangan, 67% for Sojin, and 73% for Duyou. Following seven to eight subcultures on selection media, the isoflavone content of the transformed callus lines were analyzed by high-performance liquid chromatography. The total amount of isoflavone in the transformed callus cell lines was three- to sixfold higher than that in control callus or seeds. Given the many positive effects of isoflavone on human health, it may be possible to adapt our transformed callus lines for industrialization through an alternative cell culture system to produce high concentrations of isoflavones.

Isoflavones from Phytoestrogens and Gastric Cancer Risk: A Nested Case-Control Study within the Korean Multicenter Cancer Cohort

The role of soybean products in gastric cancer risk is not clear in epidemiologic studies due to measurement error from dietary intake questionnaires and due to different degrees of bias according to study design. To examine the association between soybean products and gastric cancer risk, we measured phytoestrogen biological markers in a nested case-control study. The study population was composed of 131 cases and 393 matched controls within the Korean Multicenter Cancer Cohort. The concentrations of the four biomarkers in the plasma samples were measured using time-resolved fluoroimmunoassay. Conditional and unconditional logistic regression models were used to compute the odds ratio (OR) and 95% confidence intervals (CI). Median plasma concentrations of genistein (229 nmol/L for controls, 181.8 nmol/L for cases; P=0.07) and daidzein (131.2 nmol/L for controls, 80.5 nmol/L for cases; P=0.04) in cases were lower than in controls, whereas equol concentrations were similar. Compared with the reference group, gastric cancer risk decreased in the highest groups for genistein (OR, 0.54; 95% CI, 0.31-0.93) and daidzein (OR, 0.21; 95% CI, 0.08-0.58). Higher equol concentrations were associated with a decreased risk for gastric cancer (OR, 0.50; 95% CI, 0.27-0.90). The combination of the highest concentrations for each isoflavone category was associated with a 0.09-fold decreased risk for gastric cancer compared with the combination of the lowest concentrations for each category. There was no association between plasma lignan concentrations and gastric cancer. High serum concentrations of isoflavones were associated with a decreased risk for gastric cancer. These results suggest a beneficial effect of high soybean product intake for gastric cancer risk.

Effect of forage on the content of phyto-oestrogens in bovine milk

Phyto-oestrogens are believed to have a range of beneficial effects on predominant Western diseases. A few studies on phyto-oestrogens in milk exist and show that the composition can be affected by feeding. Therefore, the aim was to study how feeding of lucerne and grass/clover silages (GCSs) affects the concentration of phyto-oestrogens in bovine milk. Sixteen Danish Holstein cows were assigned to a 4 × 4 latin square design with four cows per treatment per period of 3 weeks. The four treatment diets were lucerne silage (LS), 2/3 lucerne silage and 1/3 maize silage (2/3LS), 1/3 lucerne silage and 2/3 maize silage (1/3LS) and GCS. Milk was collected at the end of each period and feed samples on day 6, 13 and 20 in each experimental period. Milk and pooled feed samples were analysed for the concentration of isoflavones, coumestans and lignans. The content of isoflavones was higher and the content of coumestrol lower in the GCS diet than in LS, 2/3LS and 1/3LS diets. For the LS, 2/3LS and 1/3LS diets, the concentration of coumestrol and secoisolariciresinol increased with the proportion of lucerne while the concentration of isoflavones was similar across the diets. The concentrations of the formononetin, daidzein and equol in the milk were significantly higher for the GCS diet than for the LS, 2/3LS and 1/3LS diets. In particular, the concentration of equol was 62–291 times higher for GCS. The concentration of coumestrol was significantly lower for the GCS diet compared to the LS, 2/3LS and 1/3LS diets. No pattern for the concentration of lignans was observed. In conclusion, a high concentration of isoflavones, particularly equol, and a low concentration of coumestrol were measured in the milk from the GCS diet. In contrast, a low concentration of isoflavones and a high concentration of coumestrol were measured in the milk from the LS, 2/3LS and 1/3LS diets. However, the concentration of phyto-oestrogens in bovine milk is low compared to food sources rich in phyto-oestrogens but the high concentration of equol could possibly be of therapeutic importance.