Mg Of Total Isoflavones Research Articles

Soybean-Derived Isoflavone Determination in Rumen Fluid and Milk by LC-MS-(TOF).

Soybean-derived isoflavones belong to the family of biologically active phytoestrogens. The purpose of this study was to develop a sensitive method, which permits quantification of the soybean isoflavonoids and equol in bovine rumen fluid and milk using LC-MS-(TOF). The samples of rumen fluid and milk were obtained from 12 lactating dairy cows ingesting 7,500-9,500 mg of total isoflavones daily. The validation of the developed method showed the limits of quantification to be in the range of 0.9-5.0 ng/mL. The precision was determined as relative standard deviation, which was lower than 25% in all cases. The recoveries of the most isoflavonoids were satisfactory. Lower recoveries of daidzin and glycitin can be solved by adding an internal standard. The presented method will be useful for kinetic studies of isoflavone metabolism in ruminants due to simultaneous quantification of free aglycones and glycosides in the rumen fluid.

Effect of a Soy Isoflavone Supplement on Lung Function and Clinical Outcomes in Patients With Poorly Controlled Asthma

Soy isoflavone supplements are used to treat several chronic diseases, although the data supporting their use are limited. Some data suggest that supplementation with soy isoflavone may be an effective treatment for patients with poor asthma control. To determine whether a soy isoflavone supplement improves asthma control in adolescent and adult patients with poorly controlled disease. Multicenter, randomized, double-blind, placebo-controlled trial conducted between May 2010 and August 2012 at 19 adult and pediatric pulmonary and allergy centers in the American Lung Association Asthma Clinical Research Centers network. Three hundred eighty-six adults and children aged 12 years or older with symptomatic asthma while taking a controller medicine and low dietary soy intake were randomized, and 345 (89%) completed spirometry at week 24. Participants were randomly assigned to receive soy isoflavone supplement containing 100 mg of total isoflavones (n=193) or matching placebo (n=193) in 2 divided doses administered daily for 24 weeks. The primary outcome measure was change in forced expiratory volume in the first second (FEV1) at 24 weeks. Secondary outcome measures were symptoms, episodes of poor asthma control, Asthma Control Test score (range, 5-25; higher scores indicate better control), and systemic and airway biomarkers of inflammation. Mean changes in prebronchodilator FEV1 over 24 weeks were 0.03 L (95% CI, -0.01 to 0.08 L) in the placebo group and 0.01 L (95% CI, -0.07 to 0.07 L) in the soy isoflavone group, which were not significantly different (P = .36). Mean changes in symptom scores on the Asthma Control Test (placebo, 1.98 [95% CI, 1.42-2.54] vs soy isoflavones, 2.20 [95% CI, 1.53-2.87]; positive values indicate a reduction in symptoms), number of episodes of poor asthma control (placebo, 3.3 [95% CI, 2.7-4.1] vs soy isoflavones, 3.0 [95% CI, 2.4-3.7]), and changes in exhaled nitric oxide (placebo, -3.48 ppb [95% CI, -5.99 to -0.97 ppb] vs soy isoflavones, 1.39 ppb [95% CI, -1.73 to 4.51 ppb]) did not significantly improve more with the soy isoflavone supplement than with placebo. Mean plasma genistein level increased from 4.87 ng/mL to 37.67 ng/mL (P < .001) in participants receiving the supplement. Among adults and children aged 12 years or older with poorly controlled asthma while taking a controller medication, use of a soy isoflavone supplement, compared with placebo, did not result in improved lung function or clinical outcomes. These findings suggest that this supplement should not be used for patients with poorly controlled asthma. clinicaltrials.gov Identifier: NCT01052116.

High-Dose Isoflavones Do Not Improve Metabolic and Inflammatory Parameters in Androgen-Deprived Men With Prostate Cancer

The profound hypogonadism that occurs with androgen deprivation therapy (ADT) for prostate cancer (PCa) results in complications such as diabetes and metabolic syndrome that predispose to cardiovascular disease. Because phytoestrogens have been associated with an improvement in metabolic parameters, we evaluated their role in men undergoing ADT. Our objective was to evaluate the effects of high-dose isoflavones on metabolic and inflammatory parameters in men undergoing ADT. This was a randomized, double-blind, placebo-controlled, 12-week pilot study. Participants were randomly assigned to receive 20 g of soy protein containing 160 mg of total isoflavones vs taste-matched placebo (20 g whole milk protein). The study was conducted at a tertiary care center in the United States. Thirty-three men (isoflavones = 17, placebo = 16) undergoing ADT for PCa completed this pilot study. Mean age in the 2 groups was 69 years and the majority of men were Caucasians. Mean duration of ADT in both groups was approximately 2 years (P = .70). The 2 groups were well matched at baseline. After 12 weeks of intervention, there was no significant difference in either metabolic or inflammatory parameters between the 2 groups. We found that high-dose isoflavones over a course of 12 weeks do not improve metabolic or inflammatory parameters in androgen-deprived men.

Abstract 1766: Effect of soy isoflavones on prostate cancer cell cycle regulation and apoptosis

Abstract Background: As many as one-third of all cancer deaths in the United States can be linked to diet. Significant epidemiological evidence suggests a role of a variety of dietary factors including the amount of dietary soy. In Asian countries where the average diet consists of 10 times the amount of soy products consumed compared to the average American diet there is a significantly lower incidence of prostate and breast cancer. Further supporting a dietary and environmental influence is the finding that Asian immigrants who have moved to the United States and adopt a Western diet have a prostate cancer incidence that approaches U.S. born males. These findings have been supported by other studies and, again, suggest that environmental factors such as dietary soy intake may be responsible for these differences in geographic incidence. Although there is this preclinical and epidemiological data suggesting that soy isoflavones decrease the risk of developing prostate cancer (PC), there is limited information regarding the in vivo effects of soy supplementation on human PC and benign prostate tissue. Methods: The primary objective of this study was to evaluate the molecular effects of soy isoflavones on human PC cell cycle regulation and apoptosis. Patients with histologically confirmed PC who had chosen radical prostatectomy (RRP) for treatment (without any other primary therapy) were randomized in double blind fashion to receive either soy supplementation or placebo. The patients in the treatment group received 4 capsules of a commercially available pure soy tablet (240 mg of total isoflavones) from time of enrollment until RRP. At the time of surgery, fresh tissue was collected from the tumor and adjacent normal tissue. Using these samples, we evaluated the status of genes essential for cell cycle regulation and apoptosis using cDNA microarray analyses. Results: In this preliminary analysis, multiple cell cycle and apoptotic genes were either down regulated or up regulated in the treatment samples compared to the placebo treated samples, including BAX, BCL-2, and Caspase-7. This effect was present in both tumor and adjacent normal tissue. Using samples from an additional four patients, we then further characterized these changes in gene expression using Western Blots analysis. Cleaved caspase-7 was up regulated in soy treated tumor and adjacent normal samples when compared to placebo, suggesting that soy mediates apoptosis though Caspace-7. The expression of BCL2L1 was down regulated in the treated compared to placebo tissue with this change being most marked in the adjacent normal samples. Conclusion: In total, our results suggest that soy isoflavones may exert a prostate cancer protective effect via a beneficial effect on cell cycle regulation and apoptosis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1766.

Abstract A83: Effects on serum testosterone and indicators of apoptosis and the IGF axis of soy protein isolate consumption in a randomized controlled trial with men after radical prostatectomy

Abstract Soy consumption may prevent prostate cancer and be beneficial for men with prostate cancer as suggested by epidemiologic and experimental data. However, the mechanisms by which soy might be protective are not clear, but effects on apoptosis, the insulin growth factor [IGF] axis, and steroid hormones may be involved. We have examined these factors in a randomized controlled clinical trial in which we are testing the hypothesis that soy reduces biochemical recurrence after radical prostatectomy. A standardized soy protein supplement and a casein-based placebo are consumed daily by men at elevated risk for PSA failure during the first 2 years after surgery. The soy protein isolate and placebo (Solae) were made identical in composition, except for the source of protein (20 g protein/day). The soy protein isolate provides 24 to 26 mg genistein and 40 to 43 mg of total isoflavones per day. The placebo is devoid of these and other soy-specific constituents. Self-reported compliance is excellent, serum isoflavones levels are measured as an independent compliance measure, dropout rate is low, and adverse effects minimal to non-existent. In serum samples taken at baseline, and at 2, 4, 8, 12, and 18 months from subsets of subjects we determined indicators of global apoptotic activity (soluble Fas [sFas] and Fas ligand [FasL]) and the IGF axis (IGF-1 and IGF binding protein 3 [IGFBP3]) (7–8 subjects/treatment group), and measures of androgen status, testosterone [T] and sex hormone binding globulin [SHBG] (12 subjects/group) using ELISA and enzyme immuno-assays. Data were analyzed using Generalized Estimating Equations. FasL increased slightly over time (p=0.05), but sFas did not and there were no differences in change over time for sFAs and FasL between the soy and placebo groups. Similarly, IGF-1 increased slightly over time (p=0.06), but IGFBP3 did not and there were no differences in change over time for IGF-1 and IGFBP3 between the soy and placebo groups. In contrast, T levels decreased significantly (p=0.05) from baseline over time by approx. 15% in the soy group compared to placebos, in which T levels did not change over time. SHBG levels were not changed over time or different between the two treatment groups. While data in the literature about soy effects on T and SHBG are mixed, this is the first report of soy effects on circulating T and SHBG with repeated serum sampling over as long as 1.5 years. It is also the first report about soy effects on serum sFas and FasL, while the absence of effects on the IGF axis is in line with other studies that have examined this. Thus, consuming 20 g of soy protein isolate per day for 1.5 years slightly reduced circulating T over time in the absence of changes in SHBG, but did not affect indicators of apoptosis and the IGF axis. (Supported by NIH grants CA27790 &amp; CA166195 and a grant from the Prevent Cancer Foundation.) Citation Information: Cancer Prev Res 2010;3(1 Suppl):A83.

Effects of high-dose isoflavones on metabolic and inflammatory markers in healthy postmenopausal women

After menopause, women experience changes in body composition, especially an increase in fat mass. In addition, advancing age, decreased physical activity, and increased inflammation may predispose them to develop type 2 diabetes. Isoflavones have been shown to improve metabolic parameters in postmenopausal women. However, the effect of isoflavones on adipokines/cytokines remains unclear. The purpose of this study was to evaluate the effect of high-dose isoflavones on inflammatory and metabolic markers in postmenopausal women. We measured glucose, insulin, and adipokines/cytokines in 75 healthy postmenopausal women who were randomized to receive 20 g of soy protein with 160 mg of total isoflavones (64 mg genistein, 63 mg daidzein, and 34 mg glycitein) or 20 g of soy protein placebo for 12 weeks. Women taking estrogen discontinued therapy at least 3 months before the study. The supplements were given in a powder form and consumed once daily with milk or other beverages. Mean ages in the placebo and active groups were similar (P = 0.4). Average time since menopause was 9 years, and two thirds of the women underwent natural menopause. There was no significant difference in body mass index at baseline between the groups (placebo, 25.1 kg/m; active, 26 kg/m) and it did not change significantly during the study. At baseline, the placebo group had significantly higher levels of tumor necrosis factor alpha (P < 0.0001); otherwise, there was no difference in any other parameter. After 12 weeks of treatment, there were significant positive changes in tumor necrosis factor alpha levels within the placebo group (P < 0.0001) and adiponectin levels within the isoflavone group (P = 0.03). Comparison of pre-post change between the groups showed a small but significant increase in serum adiponectin levels in the isoflavone group (P = 0.03) compared with the placebo group. No significant changes were seen in any other parameter between the two groups. Healthy, normal-weight postmenopausal women may not experience improvement in metabolic parameters when given high-dose isoflavones despite an increase in serum adiponectin levels. The role of isoflavones in obese and insulin-resistant postmenopausal women needs exploration.

Effect of high-dose isoflavones on cognition, quality of life, androgens, and lipoprotein in post-menopausal women

Recent interventional studies indicate that post-menopausal hormone replacement therapy is associated with an increased risk of cardiovascular mortality and breast cancer. Isoflavones, a class of plant estrogens, have structural similarities to estradiol. Hence, isoflavones may exert beneficial estrogenic health effects in postmenopausal women with fewer adverse effects. To evaluate the effect of high-dose isoflavones on self-reported quality of life (QOL), cognition, lipoproteins and androgen status in post-menopausal women. Double-blind, randomized, placebo-controlled, 12-week trial of 93 healthy, ambulatory, post-menopausal women (mean age 56 yr). The study was conducted at a tertiary care center in the United States. Participants were randomly assigned to receive 20 g of soy protein containing 160 mg of total isoflavones vs taste-matched placebo (20 g whole milk protein). Both soy and the placebo were provided in the form of a powder to be mixed with beverages. QOL was judged by the Menopause-specific Quality of Life (MENQOL) questionnaire while cognitive function was assessed with standard instruments. Total, free, and bioavailable testosterone, gonadotropins, SHBG, and fasting lipids were measured. Eighty-four women (90%) completed the study (active=38, placebo=46). There was a significant improvement in all 4 QOL subscales (vasomotor, psychosexual, physical, and sexual) among the women taking isoflavones, while no changes were seen in the placebo group. No significant changes in cognition, serum androgens or plasma lipids were seen within any of the groups. However, at the end of the study, a group-by-time interaction was observed such that total testosterone and HDL levels were significantly lower in the isoflavones compared to placebo groups. High-dose isoflavones is associated with improved QOL among women who have become menopausal recently. Hence, the timing of isoflavone supplementation with regards to the onset of menopause appears to be important. The use of isoflavones, as an alternative to estrogen therapy, may be potentially useful and seemingly safe in this group of women who are looking for relief from menopausal symptoms.

Diet and Risk of Ovarian Cancer in the California Teachers Study Cohort

Dietary phytochemical compounds, including isoflavones and isothiocyanates, may inhibit cancer development but have not yet been examined in prospective epidemiologic studies of ovarian cancer. The authors have investigated the association between consumption of these and other nutrients and ovarian cancer risk in a prospective cohort study. Among 97,275 eligible women in the California Teachers Study cohort who completed the baseline dietary assessment in 1995-1996, 280 women developed invasive or borderline ovarian cancer by December 31, 2003. Multivariable Cox proportional hazards regression, with age as the timescale, was used to estimate relative risks and 95% confidence intervals; all statistical tests were two sided. Intake of isoflavones was associated with lower risk of ovarian cancer. Compared with the risk for women who consumed less than 1 mg of total isoflavones per day, the relative risk of ovarian cancer associated with consumption of more than 3 mg/day was 0.56 (95% confidence interval: 0.33, 0.96). Intake of isothiocyanates or foods high in isothiocyanates was not associated with ovarian cancer risk, nor was intake of macronutrients, antioxidant vitamins, or other micronutrients. Although dietary consumption of isoflavones may be associated with decreased ovarian cancer risk, most dietary factors are unlikely to play a major role in ovarian cancer development.

Effects of phytoestrogenic isoflavones from red clover (Trifolium pratense L.) on experimental osteoporosis

The most common type of osteoporosis is bone loss associated with ovarian hormone deficiency at menopause. There is evidence that diets which contain high levels of phytoestrogenic isoflavones are associated with a low incidence of osteoporosis and menopausal symptoms. Plant extracts, which contain high levels of isoflavones, such as Red clover (Trifolium pratense L.), have been used to reduce menopausal symptoms. The objective of this study was to evaluate the preventive effects of Red clover total isoflavones on the progression of bone loss induced by estrogens deficiency (ovariectomy) in rats. Bilateral ovariectomy was performed on female Wistar rats. One week after the operation the rats were treated with an oral dose of 20 and 40 mg of total isoflavones daily for 14 weeks. The results from this study showed that the ovariectomy reduced bone mineral content, femoral weight, femoral density, mechanical strength of the tibia and increased the levels of bone specific alkaline phosphatase in the serum and the number of osteoclasts in the femur sections compared with sham operated controls. Treatment with isoflavones significantly increased bone mineral content, mechanical strength of the tibia, femoral weight, femoral density and prevented the rise of serum alkaline phosphatase levels. In addition, the treatment with isoflavones significantly reduced the number of osteoclasts compared with the ovariectomized control rats. These findings suggest that Red clover isoflavones are effective in reducing bone loss induced by ovariectomy, probably by reducing of the bone turnover via inhibition of bone resorption.

Effects of isoflavones from red clover (Trifolium pratense) on skin changes induced by ovariectomy in rats

Estrogens have a profound influence on skin. The relative hypoestrogenism that accompanies menopause exacerbates the deleterious effects of both intrinsic and environmental aging. Estrogens improve skin in many ways. Among these, they increase collagen content, skin thickness and improve skin moisture. There is evidence that diets with high levels of phytoestrogenic isoflavones are associated with a low incidence of menopausal symptoms and osteoporosis. Plant extracts such as red clover, which contain high levels of isoflavones, have been used to reduce menopausal symptoms and have been shown to reduce bone loss in healthy women. In this study to investigate the effects of red clover isoflavones on skin aging, the histology of the skin, skin thickness and the amount of total collagen determined by a colorimetric method, were studied in ovariectomized rats after treatment for 14 weeks with a red clover extract standardized to contain 11% isoflavones determined by HPLC. In ovariectomized rats the thickness and keratinization of the epidermis were reduced; glands were less in number and vascularity was poor; the distribution and morphology of the collagen bundles and elastic fibers were altered. Whereas the skin of the ovariectomized rats treated with red clover isoflavones (20 and 40 mg of total isoflavones daily for 14 weeks) appeared well organized with a normal epidermis with uniform thickness and regular keratinization; vascularity, collagen and elastic fibers were well developed. The amount of collagen significantly increased in the treated group in comparison with the control group. These findings suggest that red clover isoflavones are effective in reducing skin aging induced by estrogen deprivation.

Isoflavonas em produtos comerciais de soja

Isoflavones, associated with soy protein consumption, constitute a group of substances involved in anti-carcinogenic activity, reduction of the loss of bone mass and decrease of blood cholesterol, are considered functional compounds. Isoflavones in commercial soy foods produced in Brazil were determined. Five soy flours (SF), four textured vegetable proteins (TVP), two hydro soluble extracts (HE) and four formulated infant foods (IF) were analyzed. Isoflavone extraction was with ethanol and acetic acid and quantification and identification were accomplished by HPLC. Soy flour and textured vegetable protein contained mostly conjugated malonyl-glucosides, a SF (96mg of aglycons equivalent/100g) and TVP (70mg of aglycons equivalent /100g), obtained from the same cultivar were different in concentration and distribution of the compounds due to processing conditions. Hydro soluble extracts and formulated infant foods had aglucones varying from 8% to 28% of the total isoflavones, but the predominant isomers were b-glucosides. Twenty-five grams of soy protein a day, from SF or TVP, contribute with more than the recommended consumption of 50mg of total isoflavones a day. In the formulated infant food the concentration of total isoflavones was lower than in the other products due to addition of other ingredients.

Phytoestrogen Supplements for the Treatment of Hot Flashes: The Isoflavone Clover Extract (ICE) Study—A Randomized, Controlled Trial

Only 10% to 20% of Asian women experience hot flashes, contrasting with up to 80% of women in Western countries. One possible explanation is that the isoflavones present in soy, prominent in the Asian diet, influence bodily responses to altered hormonal levels at the time of menopause. Isoflavones are structurally related to estrogens and can bind to estrogen receptors, acting as either partial agonists or antagonists in different tissues. This study examined the efficacy and safety of 2 dietary supplements derived from red clover. Using a double-blind, placebo-controlled design, 252 menopausal women 45 to 60 years of age who had 35 or more hot flashes each week were randomly assigned to receive Promensil, providing 82 mg of total isoflavones per day; Rimostil, providing 57 mg; or a placebo. Follow up continued for 12 weeks. These women were a mean of 3.3 years past menopause and had an average of 8 hot flashes per day. In 246 women completing the 12-week trial, hot flashes were 41% less frequent than at baseline with Promensil therapy and 34% less frequent with Rimostil. Placebo patients had an average reduction of 36%, not significantly different from the effect achieved in either active treatment group. Promensil reduced hot flashes more rapidly than did placebo. Women in all groups were still having more than 5 hot flashes per day after the 12-week trial period. Per-protocol results and intention-to-treat analyses yielded similar findings. There were indications that women with relatively high body mass indices could have benefited more from phytoestrogen supplementation. The clinical results could not be related to urinary isoflavone excretion. Neither supplement was significantly associated with adverse events. Neither of the isoflavone supplements evaluated in this trial had a clinically significant effect in reducing hot flashes in these women, who were studied shortly after menopause.

Callus cultures of Genista plants—in vitro material producing high amounts of isoflavones of phytoestrogenic activity

Callus cultures of six Genista species were established with the objective to produce isoflavones of phytoestrogenic activity. The cultures were optimised for their growth and isoflavonoid production by changing various media in the presence or absence of light. The best growth and the highest isoflavone production was obtained under constant light regime on SH basal medium containing 22.6 μmol l −1 2,4-dichlorophenoxyacetic acid (2,4-D), 23.2 μmol l −1 kinetin and 3% w/v of sucrose. Callus cultures of all species produced more isoflavones than the parent herbs. The isoflavonoid group produced was composed of 14 compounds with a clear domination of genistin. In vitro cultures had lower contents of genistein esters than the herbs—possible causes are discussed. The callus with the highest isoflavone content was obtained from Genista tinctoria, producing 6586.5 mg of total isoflavones per 100 g DW, in which HPLC analysis identified 3016.3 mg of genistin.

Long-term pharmacokinetics of an extract of isoflavones from red clover (Trifolium pratense).

To study the pharmacokinetics of isoflavones from red clover (Trifolium pratense) after long-term administration as a once-daily dietary supplementary. Fourteen (14) subjects who had been consuming a low-isoflavone diet for 2 weeks were given an oral dose of two isoflavone tablets (approximately 80 mg of total isoflavones) daily for 2 weeks and appeared for a study day at 9:00 AM after an overnight fast on the day that they were to receive the last dose. Plasma samples were collected for a 48-hour period after the last dose. Plasma isoflavones were assayed by high-performance liquid chromatography (HPLC). Trough plasma levels were significantly higher for daidzein and genistein after long-term dosing than levels taken prior to the commencement of the study and plasma levels of isoflavones after long-term dosing were in the range previously reported in populations that consume an isoflavone-rich diet. The plasma half-lives observed after long-term administration were, in most cases, consistent with once-daily administration. Isoflavones have pharmacokinetic characteristics that suggest that once-daily administration is adequate when they are administered long-term as dietary supplements.

Effects of Soy Intake on Sex Hormone Metabolism in Premenopausal Women

Studies suggest that phytoestrogens in soy products may impart hormonal effects that protect women against breast cancer. Limited research suggests that intake of soy products high in isoflavonoid phytoestrogens affects sex hormone metabolism, but it is unknown whether phytoestrogens in soy have any effect on menstrual function or serum sex hormones in women on common hormone therapies, such as oral contraceptives (OC). We studied the effects of soy in 36 premenopausal women, 20 of whom used OC. Subjects consumed their normal diet for two menstrual cycles and added a soy beverage containing 20 g of protein and 38 mg of total isoflavones to their usual diet for another two menstrual cycles. No significant differences were observed in serum estrone, estradiol, sex hormone-binding globulin, dehydroepiandrosterone sulfate, prolactin, or progesterone concentrations with soy feeding in the non-OC or the OC group. No changes in menstrual cycle length or the urinary estrogen metabolite ratio of 2-hydroxyestrone to 16α-hydroxyestrone were seen with soy feeding in the non-OC or the OC group. Levels of urinary estrogen metabolites were significantly different between the non-OC and the OC group. Thus soy consumption had no significant effect on the menstrual cycle, serum sex hormones, or urinary estrogen metabolite ratio in premenopausal OC or non-OC users.

Effects of isoflavones on beany flavor and astringency of soymilk and cooked whole soybean grains

Flavor is the main limiting factor affecting soybean acceptability in the Occidental countries. The purpose of this study was to determine the effetcs of isoflavones on soybean flavor. Differences in beany flavor and astringency of soymilk and cooked whole soybean grains, prepared with cultivars IAS 5 and BR-36 (136 and 54 mg of total isoflavones /100 g of sample, respectively) with pre-soaking and pre-heating of grains, were sensorially analised, by an unstructured category scale of ascending intensity. Differences in isoflavone contents for both soybean cultivars were maintained in the two products, despite the pre-treatments in the processing. Pre-soaking of grains intensified beany flavor in the soymilk, reducing the perception of astringency, which is caused by the aglucones that were developed in reduced amounts.The whole soybeans grains cooked under pressure (1.5 kgf/cm² at 127°C) presented reduced levels of isoflavones malonyl-glucosides. Due to thermal instability, these compounds were converted to conjugated glucosides, genistin and daidzin. In the cooked whole soybean grains, no aglucones were formed and consequently it was not possible to detect differences in astringency. Results suggest that pre-heating of grains promote better flavor in soybean products.

The effect of Promensil™, an isoflavone extract, on menopausal symptoms

Objectives The primary aim was to assess whether the use of an isoflavone extract containing 40 mg or 160 mg of total isoflavones affects the frequency of menopausal flushes and other symptoms. The secondary aims were assessments of possible effects on menopause symptom scores and biological measures of estrogen activity.Methods A randomized, double-blind, placebo-controlled prospective trial of 37 postmenopausal women with symptoms of estrogen deficiency was performed over a 12-week period. The women were randomized to three treatment groups: placebo, 40 mg or 160 mg, delivered in tablet form.Results There was no significant difference in the incidence of flushes between the three groups at trial conclusion. There was no difference between the groups in Greene Menopause Symptom Scores, vaginal pH, levels of follicle stimulating hormone (FSH), sex hormone binding globulin (SHBG) or total cholesterol, liver function or blood parameters. A statistically significant increase in high-density lipoprotein (HDL) cholesterol of 18.1% (p = 0.038) occurred in the 40-mg group.Conclusion A large placebo response and inadvertent use of dietary isoflavones in the placebo group may have obscured a significant change in flushing frequency. Previous uncontrolled studies claiming a beneficial effect of foods with a high isoflavone content on menopausal symptoms may have been confounded by a large placebo response.

The effect of soy isoflavones on the development of intestinal neoplasia in Apc Min mouse

Data from epidemiological studies suggest that isoflavones in soy may have a protective effect on the development of colon cancer in humans. Therefore, we have investigated whether soy isoflavones will inhibit intestinal tumour development in Apc Min mice. The mice were fed a Western-type high risk diet (high fat, low fibre and calcium) containing two different isolates of soy protein as a protein source. For the control and test groups this resulted in the administration of about 16 and 475 mg of total isoflavones per kg diet, respectively. As a positive control, a third group of mice was administered a low isoflavone diet supplemented with 300 ppm sulindac. No significant differences in the incidence, multiplicity, size and distribution of intestinal tumours were observed between Min mice fed low and high isoflavone-containing diets. However, a clear reduction in the number of small intestinal tumours was observed for the sulindac diet. Thus, in contrast to epidemiological studies, our results demonstrate that high amounts of soy isoflavones present in a Western-type high risk diet do not protect against intestinal tumour development in a relevant animal model such as the Min mice.