Effect of γ-tocopherol supplementation on premenstrual symptoms and natriuresis: a randomized, double-blind, placebo-controlled study.

Background: This randomized, double-blind, placebo-controlled study aimed to investigate the effects of γ-tocopherol (Toc) supplementation on premenstrual symptoms and natriuresis.

Methods: We enrolled 51 Japanese women with premenstrual symptoms, particularly those who showed increased symptoms induced by water retention during the luteal phase compared with the follicular phase. Premenstrual symptoms were recorded in the first cycle's postmenstrual follicular phase; physical measurements and urine collection were conducted during the 48-h run-in period.

Optimal cut-off value for equol-producing status in women: The Japan Nurses' Health Study urinary isoflavone concentration survey.

Equol is one of the most active soy isoflavones. When the association between soy food intake in daily life and health outcomes is examined in epidemiological studies, it is important to define the equol-producing status of each individual. However, few studies have assessed equol-producing status without a soy challenge test.

Premenstrual symptoms interference and equol production status in Japanese collegiate athletes: A cross-sectional study.

Aim: Consumption of soy isoflavones reduces the risk of estrogen-related diseases, such as menopausal symptoms, osteoporosis, and cardiovascular disease. Equol is metabolized from the isoflavone daidzein by intestinal bacteria and has higher bioavailability than other isoflavones. Equol producers are believed to benefit from soybean consumption to a greater extent than non-producers.

-equol Exerts Estradiol-Like Anorectic Action with Minimal Stimulation of Estrogen Receptor-α in Ovariectomized Rats.

Chronic estrogen replacement in ovariectomized rats attenuates food intake and enhances c-Fos expression in the suprachiasmatic nucleus (SCN), specifically during the light phase. -equol, a metabolite of daidzein, has a strong affinity for estrogen receptor (ER)-β and exerts estrogenic activity. The purpose of the present study was to elucidate whether -equol exerts an estrogen-like anorectic effect by modifying the regulation of the circadian feeding rhythm in ovariectomized rats.

Relation between premenstrual syndrome and equol-production status.

Aim: Consumption of isoflavones, which are predominantly derived from soybeans, reduces the risk of estrogen-related diseases, such as menopausal symptoms, breast cancer, osteoporosis, and cardiovascular disease. Equol is more bioavailable than other soy isoflavones, and equol producers are believed to benefit to a greater extent. This study was conducted to evaluate the relation between premenstrual syndrome (PMS) and equol-production status in Japanese reproductive-age women.

Relationship of equol production between children aged 5-7 years and their mothers.

Purpose: The factors responsible for the production of isoflavone metabolites have not yet been identified. We aimed to examine the relationships of equol production between mother and child in a birth cohort in Japan.

Methods: Subjects were a part of the participants in a longitudinal study on pregnant women and their offspring.

A cross-sectional study of equol producer status and self-reported vasomotor symptoms.

Objective: This study aims to evaluate the associations of vasomotor symptom (VMS) frequency, bother, and severity with equol producer status and dietary daidzein intake.

Methods: This is an observational study. This study included women aged 45 to 55 years, in postmenopause or in the menopausal transition, who had soy food intake of three or more servings per week.

Equol producers can have low leptin levels among prediabetic and diabetic females.

Objectives: Soy isoflavones have received great attention for their beneficial effects on health and disease, i.e., in patients with diabetes.

Estrogen stimuli promote osteoblastic differentiation via the subtilisin-like proprotein convertase PACE4 in MC3T3-E1 cells.

Estrogenic compounds include endogenous estrogens such as estradiol as well as soybean isoflavones, such as daidzein and its metabolite equol, which are known phytoestrogens that prevent osteoporosis in postmenopausal women. Indeed, mineralization of MC3T3-E1 cells, a murine osteoblastic cell line, was significantly decreased in medium containing fetal bovine serum treated with charcoal-dextran to deplete endogenous estrogens, but estradiol and these soybean isoflavones dose-dependently restored the differentiation of MC3T3-E1 cells; equol was tenfold more effective than daidzein. These differentiation-promoting effects were inhibited by the addition of fulvestrant, which is a selective downregulator of estrogen receptors.

Isolation and characterization of novel S-equol-producing bacteria from brines of stinky tofu, a traditional fermented soy food in Taiwan.

Six strains capable of transforming daidzein to S-equol were isolated from the fermented brines of stinky tofu purchased in Taiwan. Daidzein was completely converted into S-equol within 24h of incubation in five strains. All the strains were gram-positive, rod-shaped, obligately anaerobic, non-motile, and non-spore-forming.

Comparative activities of the S-enantiomer and racemic forms of equol on bone fragility in ovariectomized mice.

We compared the effects of the S-enantiomer and racemic forms of equol on bone using ovariectomized (OVX) mice. Femoral bone mineral density and bone strength decreased in the OVX mice, but not in OVX mice administered 0.5 mg/d S-equol.

Discovery of an S-equol rich food stinky tofu, a traditional fermented soy product in Taiwan.

A recent epidemiological study showed that daily intake of mg quantities of S-equol is required for health-promoting effects in menopausal women. However, the maximum equol content in food was reported to be approximately 130 μg/100 g in egg yolk. The objective of this study was to find a high equol-containing food.

Identification of a novel dihydrodaidzein racemase essential for biosynthesis of equol from daidzein in Lactococcus sp. strain 20-92.

Equol is metabolized from daidzein, a soy isoflavone, by the gut microflora. In this study, we identified a novel dihydrodaidzein racemase (L-DDRC) that is involved in equol biosynthesis in a lactic acid bacterium, Lactococcus sp. strain 20-92, and confirmed that histidine-tagged recombinant L-DDRC (L-DDRC-His) was able to convert both the (R)- and (S)-enantiomers of dihydrodaidzein to the racemate.

Effects of natural S-equol supplements on overweight or obesity and metabolic syndrome in the Japanese, based on sex and equol status.

Objectives: Epidemiologic studies indicate that soy intake has an important role in the prevention of age-related health problems. Daidzein, the principal isoflavone contained in soy, is converted to S-equol by the intestinal bacteria. Not all individuals, however, can produce S-equol, which is considered the most biologically active metabolite.

A pilot study on the effects of S-equol compared to soy isoflavones on menopausal hot flash frequency.

Background: S-equol, a metabolite of the soy isoflavone daidzein, has been proposed as having potential for relief of menopausal symptoms. This study compared the efficacy of the natural S-equol supplement, SE5-OH, with isoflavones for relieving hot flashes and other menopausal symptoms.

Methods: An 8-week randomized, double-blind, active comparator trial with SE5-OH was conducted in postmenopausal women (aged 45-65 years), who experienced ≥5 hot flashes/day.

Identification of two novel reductases involved in equol biosynthesis in Lactococcus strain 20-92.

Lactococcus strain 20-92 is a bacterium that produces equol directly from daidzein under anaerobic conditions. In this study, we reveal that the transcription of the gene encoding daidzein reductase in Lactococcus strain 20-92 (L-DZNR), which is responsible for the first stage of the biosynthesis of equol from daidzein, is regulated by the presence of daidzein. We analyzed the sequence surrounding the L-DZNR gene and found six novel genes, termed orf-US4, orf-US3, orf-US2, orf-US1, orf-DS1 and orf-DS2.

A natural S-equol supplement alleviates hot flushes and other menopausal symptoms in equol nonproducing postmenopausal Japanese women.

Objective: The objective of this clinical trial was to examine the efficacy of a supplement containing natural S-(-)equol, a daidzein metabolite, in reducing menopausal symptoms.

Methods: In this multicenter, double-blind placebo-controlled trial, 160 equol nonproducing, postmenopausal Japanese women who experienced at least 1 hot flush/day were randomly assigned to consume 10 mg/day S-(-)equol (n=77 women) or placebo (n=83 women) for 12 weeks. Participants completed a standardized menopausal symptom checklist and rated five common menopause symptoms by a visual analog scale at baseline, week 12, and week 18 (6-week postintervention).

The effects of natural S-equol supplementation on skin aging in postmenopausal women: a pilot randomized placebo-controlled trial.

Objective: The aim of this study was to investigate the effects of the natural S-equol supplement on skin aging in equol-nonproducing Japanese postmenopausal women.

Methods: A randomized, double-blind, placebo-controlled trial examined the use of the natural S-equol supplement for 12 weeks in 101 postmenopausal Japanese women who were equol nonproducers. They were randomly assigned to one of three groups: placebo (n = 34), 10 mg S-equol/day (EQL10; n = 34), or 30 mg S-equol/day (EQL30; n = 33).

Effects of S-equol and natural S-equol supplement (SE5-OH) on the growth of MCF-7 in vitro and as tumors implanted into ovariectomized athymic mice.

Hormone replacement therapy (HRT) for treatment of menopausal symptoms is controversial because of reported breast cancer resulting from estrogen treatment and consequent estrogenic stimulation. S-equol, a natural metabolite of the soy isoflavone daidzein produced by intestinal bacteria, has been shown to ameliorate menopausal symptoms, with relatively low concomitant estrogenic receptor stimulation. Although synthesis of equol produces the racemate, the S-isomer may be produced in commercial amounts by bacterial fermentation of soy germ, during the production of the supplement SE5-OH.

S-equol and the fermented soy product SE5-OH containing S-equol similarly decrease ovariectomy-induced increase in rat tail skin temperature in an animal model of hot flushes.

Objective: The aim of this study was to compare the effect of SE5-OH, a fermented soy product containing S-equol, with purified S-equol on hot flushes in an ovariectomized rat model.

Methods: Eleven-week-old female Sprague-Dawley rats were assigned to either the sham group (vehicle; n = 30) or one of four ovariectomized groups: control (vehicle; n = 30), conjugated equine estrogens (CEE; 6.0 mg kg(-1) d(-1) CEE; n = 10), SE5-OH (2,000 mg kg(-1) d(-1) SE5-OH containing 11.

Prevalence of the equol-producer phenotype and its relationship with dietary isoflavone and serum lipids in healthy Chinese adults.

Background: Studies have suggested that daidzein-metabolizing phenotypes have beneficial effects on a range of health outcomes. We investigated the prevalence of equol producers and the relationship of equol phenotype with habitual isoflavone consumption and serum lipid concentrations in 200 Chinese adults in Beijing.

Methods: After the baseline survey and dietary records, 200 healthy adults in Beijing were challenged with a soy-isoflavone supplement for 3 days; 24-hour urine samples were collected before and after the challenge.

Cloning and expression of a novel NADP(H)-dependent daidzein reductase, an enzyme involved in the metabolism of daidzein, from equol-producing Lactococcus strain 20-92.

Equol is a metabolite produced from daidzein by enteric microflora, and it has attracted a great deal of attention because of its protective or ameliorative ability against several sex hormone-dependent diseases (e.g., menopausal disorder and lower bone density), which is more potent than that of other isoflavonoids.

[Prevalence of equol producer phenotype and its relations to lifestyle factors and dietary intakes among lifestyle factors and dietary intakes among healthy Chinese adults in Beijing].

Objective: To investigate the prevalence of equol producers and the physiological range of urinary equol excretion, and also to evaluate relations between equol phenotype and lifestyle among Chinese adults in Beijing.

Methods: 100 male and 100 female adults participated in a cross-sectional study and provided twice 1d urine samples on regular diet and after 3d soy isoflavone challenge respectively. A health and demographics questionnaire, and 2d food record were completed before the urine collections.

Daidzein-metabolising phenotypes in relation to serum lipids and uric acid in adults in Guangzhou, China.

Previous studies have suggested that daidzein's metabolites, equol and O-desmethylangolensin (O-DMA), rather than daidzein itself may contribute to the beneficial effects of soya foods in the prevention of CVD. The present study aims to assess the proportion of equol and O-DMA producers, and to compare differences in anthropometric factors, serum lipids, glucose and uric acid between producers and non-producers in Chinese adults aged 20-69 years. For the present cross-sectional study, 202 subjects (100 women and 102 men) were recruited.