Clinical effect of equol supplementation in the treatment of desquamative gingivitis with 1-year follow-up.

PURPOSE: Desquamative gingivitis (DG) is characterized by desquamative erosion, edematous erythema, and vesicle formation on the gingiva. Because of its prevalence in women during the pre- and postmenopausal period, its potential association with female hormones has been suggested. Equol is a soy isoflavone metabolite with a chemical structure similar to estrogen. Scientific evidence suggests that equol helps in alleviating menopausal symptoms. This study evaluated the clinical effect of a 12-month equol supplementation as a substitute for estrogen to alleviate DG symptoms. METHODS: The study enrolled 16 women with DG who regularly visited Nihon University School of Dentistry Dental Hospital. Urinary equol levels, periodontal tissue examination, O'Leary's plaque control record, stimulated saliva flow rate, and gingival pain-related questionnaires were evaluated before and after the 12-month daily intake of 10 mg equol supplement. RESULTS: Equol supplementation led to a statistically significant improvement in bleeding on probing, visual findings, and reductions in the frequency and severity of gingival pain. CONCLUSION: Urinary equol testing and equol supplementation may be novel treatment options for female patients with DG.

Indole-3-acetic acid alleviates DSS-induced colitis by promoting the production of R-equol from Bifidobacterium pseudolongum.

BACKGROUND: Inflammatory bowel disease (IBD) is characterized by immune-mediated, chronic inflammation of the intestinal tract. The occurrence of IBD is driven by the complex interactions of multiple factors. The objective of this study was to evaluate the therapeutic effects of IAA in colitis. METHOD: C57/BL6 mice were administered 2.5% DSS in drinking water to induce colitis. IAA, Bifidobacterium pseudolongum, and R-equol were administered by oral gavage and fed a regular diet. The Disease Activity Index was used to evaluate disease activity. The degree of colitis was evaluated using histological morphology, RNA, and inflammation marker proteins. CD45+ CD4+ FOXP3+ Treg and CD45+ CD4+ IL17A+ Th17 cells were detected by flow cytometry. Analysis of the gut microbiome in fecal content was performed using 16S rRNA gene sequencing. Gut microbiome metabolites were analyzed using Untargeted Metabolomics. RESULT: In our study, we found IAA alleviates DSS-induced colitis in mice by altering the gut microbiome. The abundance of Bifidobacterium pseudolongum significantly increased in the IAA treatment group. Bifidobacterium pseudolongum ATCC25526 alleviates DSS-induced colitis by increasing the ratio of Foxp3+T cells in colon tissue. R-equol alleviates DSS-induced colitis by increasing Foxp3+T cells, which may be the mechanism by which ATCC25526 alleviates DSS-induced colitis in mice. CONCLUSION: Our study demonstrates that IAA, an indole derivative, alleviates DSS-induced colitis by promoting the production of Equol from Bifidobacterium pseudolongum, which provides new insights into gut homeostasis regulated by indole metabolites other than the classic AHR pathway.

(S)-Equol Is More Effective than (R)-Equol in Inhibiting Osteoclast Formation and Enhancing Osteoclast Apoptosis, and Reduces Estrogen Deficiency-Induced Bone Loss in Mice.

BACKGROUND: Equol, a metabolite of daidzein, binds to the estrogen receptor with greater affinity than daidzein and exhibits various biological properties. It exists as an enantiomer, either (S)-equol or (R)-equol. OBJECTIVES: We have previously shown that the inhibitory effect of (S)-equol on bone fragility is stronger than that of racemic equol in ovariectomized (OVX) mice; however, the effect of (R)-equol has not been elucidated. The aim of this study was to compare the activities of equol enantiomers on bone metabolism in vitro and in vivo. METHODS: Bone marrow cells (BMCs) and RAW 264.7 cells were treated with equol enantiomers. The number of osteoclasts and caspase-3/7 activity were measured. We examined the effect of equol enantiomers on osteoblast differentiation in MC3T3-E1 cells. In vivo, 8-wk-old female ddY mice were assigned to 4 groups: sham-operated (sham), OVX, OVX + 0.5 mg/d of (S)-equol (S-eq), and OVX + 0.5 mg/d of (R)-equol (R-eq). Four weeks after the intervention, femoral bone mineral density (BMD) and osteoclastic gene expression were analyzed, along with concentrations of equol enantiomers in the serum and tissues. RESULTS: (S)-equol and (R)-equol inhibited osteoclast differentiation in BMCs (97% and 60%, P < 0.05) and RAW 264.7 cells (83% and 68%, P < 0.05). (S)-equol promoted apoptosis of mature osteoclasts by inducing caspase-3/7 activity (29%, P < 0.05) and enhanced osteoblast differentiation (29%, P < 0.05). In OVX mice, BMD was ameliorated in (S)-equol-treated mice (11%, P < 0.05), but not in (R)-equol-treated mice. The concentrations of (S)-equol were greater than those of (R)-equol in the serum, tibia, liver, and kidney (by 148%, 80%, 22%, and 139%, respectively). CONCLUSIONS: These results suggest that (S)-equol is more effective than (R)-equol in inhibiting osteoclast formation and enhancing osteoclast apoptosis in vitro, supporting the beneficial effect of (S)-equol to reduce estrogen deficiency-induced bone loss in OVX mice.

Potential Protective Effects of Equol (Soy Isoflavone Metabolite) on Coronary Heart Diseases-From Molecular Mechanisms to Studies in Humans.

Equol, a soy isoflavone-derived metabolite of the gut microbiome, may be the key cardioprotective component of soy isoflavones. Systematic reviews have reported that soy isoflavones have no to very small effects on traditional cardiovascular disease risk factors. However, the potential mechanistic mode of action of equol on non-traditional cardiovascular risk factors has not been systematically reviewed. We searched the PubMed through to July 2021 by using terms for equol and each of the following markers: inflammation, oxidation, endothelial function, vasodilation, atherosclerosis, arterial stiffness, and coronary heart disease. Of the 231 records identified, 69 articles met the inclusion criteria and were summarized. Our review suggests that equol is more lipophilic, bioavailable, and generally more potent compared to soy isoflavones. Cell culture, animal, and human studies show that equol possesses antioxidative, anti-inflammatory, and vasodilatory properties and improves arterial stiffness and atherosclerosis. Many of these actions are mediated through the estrogen receptor ß. Overall, equol may have a greater cardioprotective benefit than soy isoflavones. Clinical studies of equol are warranted because equol is available as a dietary supplement.

Roles of Phytoestrogen in the Pathophysiology of Intracranial Aneurysm.

Background and Purpose: The incidences of intracranial aneurysm and aneurysmal subarachnoid hemorrhage are high in postmenopausal women. Although population-based studies suggest that hormone replacement therapy is beneficial for postmenopausal women with intracranial aneurysms, estrogen replacement may no longer be recommended for the prevention of chronic diseases given its association with adverse outcomes, such as cancer and ischemic stroke. The isoflavone daidzein and its intestinal metabolite equol are bioactive phytoestrogens and potent agonists of estrogen receptors. Given their estrogenic properties, we investigated whether the isoflavones daidzein and equol are protective against the formation and rupture of intracranial aneurysms in a mouse model of the postmenopausal state. Methods: We induced intracranial aneurysms in ovariectomized adult female mice using a combination of induced systemic hypertension and a single injection of elastase into the cerebrospinal fluid. We fed the mice with an isoflavone-free diet with/without daidzein supplementation, or in a combination of intraperitoneal equol, or oral vancomycin treatment. We also used estrogen receptor beta knockout mice. Results: Both dietary daidzein and supplementation with its metabolite, equol, were protective against aneurysm formation in ovariectomized mice. The protective effects of daidzein and equol required estrogen receptor-ß. The disruption of the intestinal microbial conversion of daidzein to equol abolished daidzein's protective effect against aneurysm formation. Mice treated with equol had lower inflammatory cytokines in the cerebral arteries, suggesting that phytoestrogens modulate inflammatory processes important to intracranial aneurysm pathogenesis. Conclusions: Our study establishes that both dietary daidzein and its metabolite, equol, protect against aneurysm formation in ovariectomized female mice through the activation of estrogen receptor-ß and subsequent suppression of inflammation. Dietary daidzein's protective effect required the intestinal conversion to equol. Our results indicate the potential therapeutic value of dietary daidzein and its metabolite, equol, for the prevention of the formation of intracranial aneurysms and related subarachnoid hemorrhage.

Selective Estrogen Receptor ß Agonists: a Therapeutic Approach for HIV-1 Associated Neurocognitive Disorders.

The persistence of HIV-1 associated neurocognitive disorders (HAND) in the post-cART era, afflicting between 40 and 70% of HIV-1 seropositive individuals, supports a critical need for the development of adjunctive therapeutic treatments. Selective estrogen receptor ß agonists, including S-Equol (SE), have been implicated as potential therapeutic targets for the treatment of neurocognitive disorders. In the present study, the therapeutic efficacy of 0.2 mg SE for the treatment of HAND was assessed to address two key questions in the HIV-1 transgenic (Tg) rat. First, does SE exhibit robust therapeutic efficacy when treatment is initiated relatively early (i.e., between 2 and 3 months of age) in the course of viral protein exposure? Second, does the therapeutic utility of SE generalize across multiple neurocognitive domains? Treatment with SE enhanced preattentive processes and stimulus-response learning to the level of controls in all (i.e., 100%) HIV-1 Tg animals. For sustained and selective attention, statistically significant effects were not observed in the overall analyses (Control: Placebo, n = 10, SE, n = 10; HIV-1 Tg: Placebo, n = 10, SE, n = 10). However, given our a priori hypothesis, subsequent analyses were conducted, revealing enhanced sustained and selective attention, approximating controls, in a subset (i.e., 50%, n = 5 and 80%, n = 8, respectively) of HIV-1 Tg animals treated with SE. Thus, the therapeutic efficacy of SE is greater when treatment is initiated relatively early in the course of viral protein exposure and generalizes across neurocognitive domains, supporting an adjunctive therapeutic for HAND in the post-cART era. Graphical Abstract HIV-1 transgenic (Tg) and control animals were treated with either 0.2 mg S-Equol (SE) or placebo between 2 and 3 months of age (Control: Placebo, n = 10, SE, n = 10; HIV-1 Tg: Placebo, n = 10, SE, n = 10). Neurocognitive assessments, tapping preattentive processes, stimulus response learning, sustained attention and selective attention, were conducted to evaluate the utility of SE as a therapeutic for HIV-1 associated neurocognitive disorders (HAND). Planned comparisons between HIV-1 Tg and control animals treated with placebo were utilized to establish a genotype effect, revealing prominent neurocognitive impairments (NCI) in the HIV-1 Tg rat across all domains. Furthermore, to establish the utility of SE, HIV-1 Tg animals treated with SE were compared to control animals treated with placebo. Treatment with 0.2 mg SE ameliorated NCI, to levels that were indistinguishable from controls, in at least a subset (i.e., 50-100%) of HIV-1 Tg animals. Thus, SE supports an efficacious, adjunctive therapeutic for HAND.

(±)-Equol does not interact with genistein on estrogen-dependent breast tumor growth.

Equol (EQ) is a prominent microbial metabolite of the soy isoflavone, daidzein, with estrogen-like properties. The major soy isoflavone, genistein (GEN), stimulated growth of estrogen-dependent breast cancer (EDBC) cells in vitro and tumor growth in vivo but EQ did not. To understand possible interactions of EQ and GEN on EDBC, EQ was used with GEN in combination in vitro and in vivo. Effects of EQ, GEN and EQ + GEN were evaluated using MCF-7 and T47D EDBC. Ovariectomized athymic mice were used as a model for in vivo tumor growth. Dietary EQ had no effect on MCF-7 tumor growth and the absence of effect was confirmed using a T47D EDBC in vivo model. EQ alone or in combination with GEN increased EDBC cell proliferation in vitro. EQ alone neither stimulated EDBC tumor growth in vivo at various doses nor suppressed tumor growth induced by dietary GEN. In summary, EQ has similar estrogenic effect as GEN in vitro but does not interact with GEN on EDBC tumor growth. Based on the evidence presented here, dietary EQ is unlikely to have estrogenic effects in vivo.

Opposing effects of S-equol supplementation on metabolic and behavioral parameters in mice fed a high-fat diet.

Phytoestrogens, such as daidzein and genistein, may be used to treat various hormone-dependent disorders. Daidzein can be metabolized by intestinal microbes to S-equol. However, not all individuals possess bacteria producing this metabolite, resulting in categorization of equol vs nonequol producers. Past human and rodent studies have suggested that supplementation of this compound might yield beneficial metabolic and behavioral effects. We hypothesized that administration of S-equol to diet-induced obese male and female mice would mitigate potential diet-induced metabolic and comorbid neurobehavioral disorders. To test this possibility, we placed 5-week-old C57 mice on a high-fat diet (HFD) to mimic the diet currently consumed by many Western adults. Animals were randomly assigned to S-equol supplementation (10 mg/kg body weight) or vehicle control group. After 4 weeks on HFD with or without S-equol supplementation, metabolic and behavioral phenotyping was performed. Although the initial hypothesis proposed that S-equol treatment would improve metabolic and neurobehavioral outcomes, this supplementation instead exacerbated aspects of HFD-induced metabolic disease, as indicated by suppressed physical activity in treated individuals, reduced energy expenditure in treated males, and serum chemistry changes (hyperglycemia in treated individuals; hyperinsulinemia and hypoleptinemia in treated males). Conversely, S-equol individuals exhibited less anxiety-like and depressive-like behaviors, as evidenced by increased exploratory time in the elevated plus maze by treated males and increased time spent mobile in the tail suspension test for treated individuals. In summary, S-equol may be beneficial in mitigating depression and anxiety disorders in individuals, but for indeterminate reasons, supplementation may worsen facets of metabolic disorders in obese individuals.

Equol Decreases Hot Flashes in Postmenopausal Women: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

Soy isoflavones may benefit some, but not all, menopausal women, and the ability of the women to produce equol may be the major determinant of effectiveness. We assessed the efficacy of soy isoflavones and equol for alleviating menopausal symptoms, especially vasomotor symptoms, in postmenopausal women who were equol producers and nonproducers by using systematic review and meta-analysis of randomized clinical trials (RCTs). We searched 12 English, Korean, and Chinese language scientific and medical databases. We selected all available RCTs that assessed the effect of equol, either equol itself or soy isoflavone in equol producers, on menopausal symptoms in peri- or postmenopausal women. The primary outcome was the effect on hot flashes. The severity of hot flashes was determined by the scores, and sensitivity and risk of bias analyses were conducted. Other outcomes of the review, but not meta-analysis, included depression and adverse events. Six studies (779 total subjects) met all criteria for the systematic review, 5 of those could be included in the meta-analysis (728 total subjects). Two studies included in the meta-analysis reported no statistically significant benefits of equol; the other three did report significant benefits of equol. Meta-analysis revealed a significant benefit of equol for lowering hot flash scores and revealed a generally low risk of bias. In conclusion, this study found that supplementing equol to equol nonproducers significantly lowered the incidence and/or severity of hot flashes in menopausal women.

Effectiveness of natural S-equol supplement for premenstrual symptoms: protocol of a randomised, double-blind, placebo-controlled trial.

INTRODUCTION: Premenstrual syndrome (PMS) comprises a range of mood, behavioural and physical symptoms, and impairs many women's quality of life. Isoflavones are expected to stabilise the natural fluctuation of the oestrogen cycle through their selective oestrogen receptor modulator-like activities that alleviate PMS symptoms. Equol, a metabolite of a soy isoflavone converted from daidzein by specific gut bacteria, has a greater bioavailability compared with other soy isoflavones. We aim to examine the effect of natural S-equol supplements on premenstrual symptoms. METHODS AND ANALYSIS: This study will enrol 124 women (aged 20-45 years) who have PMS symptoms and are non-equol producers in a double-blind, parallel, randomised, placebo-controlled trial, in which they will receive natural S-equol supplement (equol 10 mg a day) or placebo, orally, twice daily, for three menstrual cycles. The primary outcome measure (Daily Record of Severity of Problems total score) will be assessed during intervention cycles. To compare the primary outcomes between the S-equol group and the placebo group, the mean differences in the Daily Record of Severity of Problems total score between the two groups will be determined. The p values will be determined using Student's t-test, where the significance level is 5% (two-sided). ETHICS AND DISSEMINATION: The institutional review board at Kindai University approved the study. The findings of this trial will be submitted to an international peer-reviewed journal. Abstracts will be submitted to national and international conferences. TRIAL REGISTRATION NUMBER: UMIN000031815.

Effects of Equol Supplement on Bone and Cardiovascular Parameters in Middle-Aged Japanese Women: A Prospective Observational Study.

OBJECTIVE: To examine changes in the bone and cardiovascular parameters and tolerability in middle-aged Japanese women taking equol supplement for a year. DESIGN: This was a prospective observational study. SUBJECTS AND SETTING: Participants were 74 women receiving outpatient care at Hamasite Medical Clinic, Minato-ku, Tokyo, from 2013 to 2015. INTERVENTIONS: Participants received per oral equol-containing supplement, 10 mg/day. OUTCOME MEASURES: The primary outcome measures were percent changes in bone and cardiovascular parameters after 1 year supplementation with equol. The secondary measures included factors affecting the parameter changes and adverse effects associated with equol use for a year. RESULTS: Reduction in arterial stiffness was observed after 12 months of equol supplement (1402.3 cm/s vs.1367.3 cm/s, p < 0.001). Significant reductions in respective parameters were observed in women with moderate and high risk for arteriosclerosis (median [95% confidence interval]: -3.2% [-5.79 to -0.74]; -12.65% [-18.52 to -4.28]; respectively); hypertriglyceridemia -45.53% [-70.24 to -5.58]; bone resorption risk (-15.15% [-23.71 to 1.56]; and bone fracture risk -26.68% [-76.43 to -5.99]. All 15 women with high baseline parathyroid hormone levels had achieved a median of 50% [-54.11 to -31.69] reduction from their baseline values. These associations were further confirmed in the results of multiple linear regression analysis. There were no reported adverse events or abnormal findings in the blood chemistry, Pap smear, mammography, and transvaginal ultrasound during periodic follow-ups. CONCLUSION: One year equol supplement was tolerable and induced improvement of certain bone and cardiovascular parameters, especially in higher risk groups. Further controlled studies are needed to explore long-term equol use for wellbeing of middle-aged women.

1H Nuclear Magnetic Resonance Based Metabolomics Approach Reveals the Metabolic Mechanism of (-)-5-Hydroxy-equol against Hepatocellular Carcinoma Cells in Vitro.

1H nuclear magnetic resonance (NMR)-based metabolomics can rapidly detect metabolic shift under various stimulus; thus, it facilitated the dissection of the therapeutic mechanisms of compounds. (-)-5-Hydroxy-equol is an isoflavone metabolite that be obtained by microbial biotransformation. In the current work, the effect of (-)-5-hydroxy-equol on hepatocellular carcinoma (HCC) cells and its mechanism have been explored based on 1H NMR-based metabolomics approach. Our results revealed that (-)-5-hydroxy-equol can significantly inhibit the proliferation, migration, and invasion of SMMC-7721 cells and inhibit the proliferation of HepG2 cells. Metabolomics revealed that 17 differential metabolites involving in amino acid metabolism and energy metabolism were significantly changed inside and outside of the cells after treatment of (-)-5-hydroxy-equol. Specifically, (-)-5-hydroxy-equol at a concentration of 30 µM significantly decreased the concentrations of pyruvate, glutamate, and glucose. Because glycometabolism is a crucial feature of cancer-specific metabolism, we further verified enzymes and proteins that are closely relevant to glycometabolism. Our results indicated that (-)-5-hydroxy-equol-modulated glycolysis in HCC through the inhibition of activities of hexokinase, phosphofructokinase, and pyruvate kinase, and the expression of pyruvate kinase M2. This study revealed that metabolomic analysis integrating with further verifications at the biochemical level can facilitate understanding the anti-HCC mechanisms of (-)-5-hydroxy-equol.

Vaginal health of postmenopausal women on nutraceutical containing equol.

OBJECTIVE: The aim of the study was to evaluate the effects of nutraceuticals containing equol on vaginal health of postmenopausal women with vulvovaginal symptoms and dyspareunia. METHODS: One hundred twenty-six natural postmenopausal women on +1b +1c (2 and 3-6 y after the final menstrual period, respectively) of the Stages of Reproductive Aging Workshop were enrolled in a nonrandomized trial. Of these, 72 women accepted to use nutraceutical (group A). The remaining 54 women refused the treatment and participated as the control group (group B). Group A was prescribed one tablet daily to take orally, for 8 months. All assessments were made at baseline and at 4 and 8 months. Determination of vaginal maturation index (VMI), evaluation of vaginal pH, and assessment of vaginal atrophy symptoms by the vaginal health index (VHI) were carried out. Dyspareunia score was also measured. RESULTS: Group A had a significant increase in VMI (68 ±â€Š5 vs 58 ±â€Š8) and improvement of vaginal pH (4.1 ±â€Š1.3 vs 5.1 ±â€Š1.7) compared with baseline, mainly after 8 months of treatment (P < 0.001). Group A had an improvement of VHI after 4 (13 ±â€Š3, P < 0.01) and 8 (16 ±â€Š2, P < 0.001) months of nutraceutical intake. Dyspareunia reduced after 8 months (5.1 ±â€Š1.3 vs 3.8 ±â€Š1.2, P < 0.001) but not after 4 months (4.7 ±â€Š1.1, P = 0.06) of treatment. Group B showed no changes from baseline evaluation (P = 0.22). CONCLUSIONS: Nutraceuticals containing equol could be effective in modulating postmenopausal symptoms, particularly vaginal symptoms, and could be well accepted by the women who usually do not wish to use hormone therapy or cannot use it for medical reasons.

Influence of equol and resveratrol supplementation on health-related quality of life in menopausal women: A randomized, placebo-controlled study.

OBJECTIVE: This study was designed to evaluate the effects of equol and resveratrol supplementation on health-related quality of life (HRQoL) in otherwise healthy menopausal women with hot flashes, anxiety and depressive symptoms. METHODS: Sixty recently menopausal women aged 50-55 years were randomized in a 12-week, placebo-controlled trial to receive 200mg of fermented soy containing 10mg of equol and 25mg of resveratrol (1 tablet/day). The primary outcome was the change in score on the Menopause Rating Scale (MRS), used to evaluate the severity of age-/menopause-related complaints. Additional outcome measures included the subject-reported score on the Hamilton Rating Scale for Depression (HAM-D) and Nottingham Health Profile (NHP), which was used specifically to assess sleep quality. RESULTS: The symptoms assessed by the MRS improved during treatment in the active group. Comparison between placebo and treatment groups revealed statistically significant improvement in particular for dryness of vagina (-85.7%) (p<0.001), heart discomfort (-78.8%; p<0.001) and sexual problems (-73.3%; p<0.001). On the HAM-D significant improvements at week 12 were seen in work and activities (-94.1%) (p<0.001). Subjects treated with equol and resveratrol also had significant differences in the sleep domain of the NHP (p<0.001). CONCLUSION: These findings provide evidence that 12 weeks of dietary supplementation with equol and resveratrol may improve menopause-related quality of life in healthy women.

Skin aging and oxidative stress: Equol's anti-aging effects via biochemical and molecular mechanisms.

Oxygen in biology is essential for life. It comes at a cost during normal cellular function, where reactive oxygen species (ROS) are generated by oxidative metabolism. Human skin exposed to solar ultra-violet radiation (UVR) dramatically increases ROS production/oxidative stress. It is important to understand the characteristics of human skin and how chronological (intrinsic) aging and photo-aging (extrinsic aging) occur via the impact of ROS production by cascade signaling pathways. The goal is to oppose or neutralize ROS insults to maintain good dermal health. Botanicals, as active ingredients, represent one of the largest categories used in dermatology and cosmeceuticals to combat skin aging. An emerging botanical is equol, a polyphenolic/isoflavonoid molecule found in plants and food products and via gastrointestinal metabolism from precursor compounds. Introductory sections cover oxygen, free radicals (ROS), oxidative stress, antioxidants, human skin aging, cellular/molecular ROS events in skin, steroid enzymes/receptors/hormonal actions and genetic factors in aging skin. The main focus of this review covers the characteristics of equol (phytoestrogenic, antioxidant and enhancement of extracellular matrix properties) to reduce skin aging along with its anti-aging skin influences via reducing oxidative stress cascade events by a variety of biochemical/molecular actions and mechanisms to enhance human dermal health.

Equol suppresses inflammatory response and bone erosion due to rheumatoid arthritis in mice.

Rheumatoid arthritis (RA) is a chronic and systemic autoimmune inflammatory disease. Typical pathological findings of RA include persistent synovitis and bone degradation in the peripheral joints. Equol, a metabolite of the major soybean isoflavone daidzein, shows superior bioactivity than other isoflavones. We investigated the effects of equol administration on inflammatory response and bone erosion in mice with collagen-induced arthritis (CIA). The severity of arthritis symptoms was significantly low in the equol-administered CIA mice. In addition, equol administration improved the CIA-induced bone mineral density decline. In the inflamed area of CIA mice, equol administration suppressed the expression of interleukin-6 and its receptor. Furthermore, equol reduced the expression of genes associated with bone formation inhibition, osteoclast and immature osteoblast specificity and cartilage destruction. These results suggest that equol suppresses RA development and RA-induced bone erosion by regulating inflammation and bone metabolism.

Research protocol: effect of natural S-equol on blood pressure and vascular function--a six-month randomized controlled trial among equol non-producers of postmenopausal women with prehypertension or untreated stage 1 hypertension.

BACKGROUND: Although higher habitual soy intake is associated with lower blood pressure (BP) and stroke incidence, clinical trials using soy protein or isoflavones on cardiovascular risks yielded inconsistent results. The discrepancies are hypothesized to be due to the individuals' intestinal bacterial capacity to metabolite isoflavones daidzein into equol. Animal and in vitro studies have revealed that equol has stronger estrogen-like and anti-oxidative activity than isoflavones and possesses natriuretic and vasorelaxant properties which may play an important role in the prevention of hypertension. However, no clinical trial has examined the effect of equol on BP. We thus propose a 24-week randomized controlled trial to test the effectiveness of natural S-equol on BP and vascular function among equol non-producers. METHODS/DESIGN: This will be a 6-month double-blind, randomized, placebo-controlled trial among 207 non-equol producing postmenopausal women with prehypertension or early untreated hypertension. Eligible participants who have completed a 2-week run-in will be randomized to either one of the 3 groups: placebo group, low-equol group (10 mg/d) and high equol group (20 mg/d). The outcome measures will be conducted at baseline and at the end of the trial including 24 h ambulatory BP, endothelial function (by ultrasound determined brachial flow mediated dilation), arterial stiffness (by pulse wave analysis) and other cardiovascular risk factors (lipid profile, glycemic control and inflammatory biomarkers). Urinary isoflavones will be tested for compliance assessment. One way analysis of variance will be applied to compare the 6-month changes in ambulatory BP or parameters of vascular function among the 3 treatment groups. DISCUSSION: This study will be performed in community subjects. If the antihypertensive effect of equol is proven, the provision of natural equol to those high risk adults who are unable to produce equol will have enormous public health implications for the primary and secondary prevention of hypertension and cardiovascular diseases on a population basis. The research efforts will also have significant implications for industry in the provision of suitable soy products for the prevention of hypertension and its related complications. TRIAL REGISTRATION: The trial was registered in ClinicalTrials.gov with identifier of NCT02515682 .

Cancer therapy using natural ligands that target estrogen receptor beta.

Estrogen receptor beta (ERß) is one of the two key receptors (ERα, ERß) that facilitate biological actions of 17ß-estradiol (E2). ERß is widely expressed in many tissues, and its expression is reduced or lost during progression of many tumors. ERß facilitates estrogen signaling by both genomic (classical and non-classical) and extra-nuclear signaling. Emerging evidence suggests that ERß functions as a tissue-specific tumor suppressor with anti-proliferative actions. Recent studies have identified a number of naturally available selective ERß agonists. Targeting ERß using its naturally available ligands is an attractive approach for treating and preventing cancers. This review presents the beneficial actions of ERß signaling and clinical utility of several natural ERß ligands as potential cancer therapy.

[Prostate cancer prevention].

Environmental factors, mainly diet, play an important role in the development of prostate cancer. A previous study identified fat and calcium as risk factors, and lycopene, selenium, soy isoflavone, and vitamin E as preventive factors for the development of prostate cancer. However, many previous studies were observational or in vitro/in vivo based, and enough evidence in a large-scale randomized study has not been provided. In the study of food, not only the intake but also the metabolism is important. For soy isoflavone, analysis of enterobacterial flora concerned with its metabolism to equol is in progress.

Equol is neuroprotective during focal cerebral ischemia and reperfusion that involves p-Src and gp91(phox).

Both of gp91(phox) (an isoform of nicotinamide adenine dinucleotide phosphate reduced oxidases) and Src (a nonreceptor protein tyrosine kinase) are abundantly expressed in the brain and play a prominent role in mediating ischemic alteration in neurons. The inhibitory strategy of them is believed to be the promising treatment of stroke. The present study was designed to investigate the effect of equol (0.625-2.5 mg·kg(-1), i.g. for 3 days), a predominant active metabolite of daidzein, on neuroprotection against cerebral ischemia/reperfusion injury in rats and the underlying mechanisms. We found that equol decreased the mortality, neurological deficit, brain histological damage, infarct volume, serum lactate dehydrogenase activity and malondialdehyde content in a dose-dependent manner in rats with 2-h middle cerebral artery occlusion, followed by 22-h reperfusion. Western blot analysis revealed that protein levels of gp91(phox) and phosphorylated Src-Tyr416 (p-Src) in ischemic cerebral cortex were increased in rats treated with vehicle, which was reversed in animals treated with equol. In rat pheochromocytoma cell line (PC12) with hypoxia/reoxygenation injury, silencing of gp91(phox) with specific siRNA did not affect the increase of p-Src level by hypoxia/reoxygenation injury and the inhibition of p-Src level by equol, while silencing of Src suppressed the upregulation of gp91(phox) by hypoxia/reoxygenation injury and enhanced the inhibitory effect of equol on gp91(phox) expression. These results demonstrate that equol confers a neuroprotection in rats via inhibiting the activation of Src and upregulation of gp91(phox) induced by focal cerebral ischemia/reperfusion, and Src may play a partial role in regulating gp91(phox) expression of neurons.