Molecular effects of genistein on estrogen receptor mediated pathways

The Mechanism of Pyroptosis and Its Application Prospect in Diabetic Wound Healing

Pyroptosis defines a form of pro-inflammatory-dependent programmed cell death triggered by gasdermin proteins, which creates cytoplasmic pores and promotes the activation and accumulation of immune cells by releasing several pro-inflammatory mediators and immunogenic substances upon cell rupture. Pyroptosis comprises canonical (mediated by Caspase-1) and non-canonical (mediated by Caspase-4/5/11) molecular signaling pathways. Numerous studies have explored the contributory roles of inflammasome and pyroptosis in the progression of multiple pathological conditions such as tumors, nerve injury, inflammatory diseases and metabolic disorders. Accumulating evidence indicates that the activation of the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome results in the activation of pyroptosis and inflammation. Current evidence suggests that pyroptosis-dependent cell death plays a progressive role in the development of diabetic complications including diabetic wound healing (DWH) and diabetic foot ulcers (DFUs). This review presents a brief overview of the molecular mechanisms underlying pyroptosis and addresses the current research on pyroptosis-dependent signaling pathways in the context of DWH. In this review, we also present some prospective therapeutic compounds/agents that can target pyroptotic signaling pathways, which may serve as new strategies for the effective treatment and management of diabetic wounds.

Genistein Co-Amorphous Systems with Amino Acids: An Investigation into Enhanced Solubility and Biological Activity

Genistein, an isoflavone known for its antioxidant and antidiabetic effects, suffers from the drawback of low solubility. To overcome this limitation, co-amorphous systems were synthesized by incorporating amino acids that were chosen through computational methods. The confirmation of the amorphous state of lysine and arginine-containing systems was ascertained by X-ray powder diffraction. Subsequently, the characterization of these systems was extended by employing thermo-gravimetry, differential scanning calorimetry, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The investigation also included an assessment of the physical stability of the samples during storage. The apparent solubility of the systems was studied in an aqueous medium. To evaluate the in vitro permeability through the gastrointestinal tract, the parallel artificial membrane permeability assay was employed. The biological properties of the systems were assessed with regard to their antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl and cupric ion-reducing antioxidant capacity assays, as well as their ability to inhibit α-glucosidase. The systems' glass transition temperatures were determined, and their homogeneity confirmed via differential scanning calorimetry analysis, while Fourier-transform infrared spectroscopy analysis provided data on molecular interactions. Stability was maintained for the entire 6-month storage duration. The co-amorphous system containing lysine displayed the most pronounced apparent solubility improvement, as well as a significant enhancement in antioxidant activity. Notably, both systems demonstrated superior α-glucosidase inhibition relative to acarbose, a standard drug for managing type 2 diabetes. The results indicate that co-amorphous systems with lysine and arginine have the potential to significantly enhance the solubility and biological activity of genistein.

Thermal conversion kinetics and solubility of soy isoflavones in subcritical water extraction

The conversion of isoflavones during subcritical water extraction were studied using first-order reaction kinetics modeling. Isoflavones were extracted from soybean using temperatures from 100℃ to 180℃ for 3 to 30 min. It was found that malonylgenistin was the most thermally unstable, with little being detected above 100℃. The optimal extraction temperatures for acetylgenistin (AG), genistin (G), and genistein (GE) were 120℃, 150℃, and 180℃, respectively. A larger sum of the numbers of both hydroxyl groups and oxygen molecules was associated with a lower melting point and optimal extraction temperature. Kinetics modeling of reaction rate constant k and activation energy E_a showed that all of the reaction rates tended to increase with temperature, with the relationship fitted well by a first-order model in nonlinear regression. For temperatures between 100℃ and 150℃, AG → G and AG → GE conversions showed the highest rate constants, but G → GE and G → D₃ (degraded G) conversions became dominant at 180℃. Chemical compounds studied in this article: genistein (PubChem CID: 5280961), genistin (PubChem CID: 5281377), 6″-O-malonylgenistin (PubChem CID: 15934091), 6″-O-acetylgenistin (PubChem CID: 5315831).

Genistein Inhibits Clostridioides difficile Infection via Estrogen Receptors and Lysine-Deficient Protein Kinase 1

BACKGROUND

Clostridioides difficile infection (CDI) is a debilitating nosocomial disease. Postmenopausal women may have an increased risk of CDI, suggesting estrogen influence. Soybean products contain a representative estrogenic isoflavone, genistein.

METHODS

The anti-inflammatory and antiapoptotic effects of genistein were determined using primary human cells and fresh colonic tissues. The effects of oral genistein therapy among mice and hamsters were evaluated.

RESULTS

Within 10 days of CDI, female c57BL/6J mice in a standard environment (regular diet) had a 50% survival rate, while those with estrogen depletion and in an isoflavone-free environment (soy-free diet) had a 25% survival rate. Oral genistein improved their 10-day survival rate to 100% on a regular diet and 75% in an isoflavone-free environment. Genistein reduced macrophage inflammatory protein-1α (MIP-1α) secretion in fresh human colonic tissues exposed to toxins. Genistein inhibited MIP-1α secretion in primary human peripheral blood mononuclear cells, abolished apoptosis and BCL-2-associated X (BAX) expression in human colonic epithelial cells, and activated lysine-deficient protein kinase 1 (WNK1) phosphorylation in both cell types. The anti-inflammatory and antiapoptotic effects of genistein were abolished by inhibiting estrogen receptors and WNK1.

CONCLUSIONS

Genistein reduces CDI disease activity by inhibiting proinflammatory cytokine expression and apoptosis via the estrogen receptor/G-protein estrogen receptor/WNK1 pathways.

Understanding the Phytoestrogen Genistein Actions on Breast Cancer: Insights on Estrogen Receptor Equivalence, Pleiotropic Essence and Emerging Paradigms in Bioavailability Modulation

Prevalent as a major phenolic ingredient of soy and soy products, genistein is recognized as an eminent phytoestrogen owing to its interacting ability with estrogen receptors (ERs). The metabolic conversion of plant-derived genistin to genistein by gut microbes and intestinal enzymes enhances its absorption at intestinal pH of ~7.5-7.8. Genistein interferes in breast cancer (BC) development via pleiotropic actions on cell proliferation, survival, angiogenesis, and apoptosis. Though multiple investigations have demonstrated genistein intake-driven reduced BC risk, similar efficacy has not been replicated in clinical trials. Furthermore, multiple studies have structurally and functionally equated genistein extents with 17-β-estradiol (E2), the most available physiological estrogen in females, culminating in aggravated BC growth. Of note, both genistein and E2 function via interacting with ERs (ERα and ERβ). However, although E2 shows almost equal affinity towards both ERα and ERβ, genistein shows more affinity towards ERβ than ERα. Our cautious literature survey revealed typical intake mode, ER expression pattern and the ratio of ERα and ERβ, transactivators/ regulators of ERα and ERβ expression and activities, patient age, and menopausal status as decisive factors affecting genistein BC activities. Of further interest are the mechanisms by which genistein inhibits triple-negative breast cancers (TNBCs), which lack ERs, progesterone receptors (PRs), and human epidermal growth factor receptors (HER2). Herein, we attempt to understand the dosage-specific genistein actions in BC cells and patients with an insight into its better response via derivative development, nanocarrier-assisted, and combinatorial delivery with chemotherapeutic drugs.

Effect of Soybean Isoflavones on Proliferation and Related Gene Expression of Sow Mammary Gland Cells In Vitro

The present study was conducted to investigate the effects of synthetic soybean isoflavones (ISO) on the proliferation and related gene expression of sow mammary gland cells. Cells were cultured with 0 (control), 10, 20, or 30 μM of ISO under incubation conditions. After a 48 h incubation, these ISO-incubated cells proliferated more (p < 0.05) than the control cells. Cyclin E expression was higher (p < 0.05) in the 10 μM ISO and 20 μM ISO treatment groups than in the control group. Cyclin D1 and p21 expressions decreased (p < 0.05) with the 10 μM ISO treatment for 48 h. The relative mRNA abundances of the cells’ IG-1R (Insulin-like growth factor-1R), EGFR (Epidermal growth factor receptor), STAT3 (Signal transducer and activator of transcription 3) and AKT (protein kinase B) were enhanced (p < 0.05) by the 20 μM ISO treatment for 24 h and 48 h in the medium. The relative mRNA abundances of κ-casein at 48 h of incubation and β-casein at 24 h and 48 h of incubation were increased (p < 0.05) by 10 μM of ISO supplementation. It was concluded that ISO improved the proliferation of sow mammary gland cells, possibly by regulating cyclins and function genes expression in the cell proliferation signaling pathway.

Genistein Up-Regulates the Expression of EGF and E-Cadherin in the Treatment of Senile Vaginitis

Investigating the therapeutic effect of genistein (Gen) on postmenopausal senile vaginitis (SV) and its mechanism of action. Adult SPF female Wistar rats were selected to establish a bilateral ovariectomized animal model (OVX), which simulated senile vaginitis dominated by estrogen deficiency in ovarian dysfunction. After 14 days of continuous treatment, the morphology of vaginal epithelial tissue was observed and various types of epithelial cells were counted, and the body mass and uterine and vaginal index of rats were measured. the levels of vaginal tissue secretion, microorganism, hormone and glycogen in each group were measured and the reproductive health was evaluated clinically. The protein expression and mRNA expression of epidermal growth factor (EGF) and E-cadherin (E-cadherin) in vaginal tissues were detected by immunohistochemistry and RT-PCR, respectively. Result showed that Genistein lowered vaginal pH, increased vaginal index and vaginal health score, thickened epithelial layers and improved vaginal tissue atrophy after administration. Genistein also increased the contents of glycogen and Lactobacillus in vagina, and promoted the expression of EGF, E-cadherin protein and mRNA. To sum up, there is no significant change in serum E2 and FSH levels, indicating that genistein has no effect on hormone levels in rats. genistein promoted the proliferation of vaginal epithelial cells, thickened epithelial layers and the vaginal wall, which improved the resistance of vaginal epithelium, the recovery of self-cleaning ability and healed the vaginal wound and erosive surface to improve atrophy.

Genistein, a Potential Phytochemical against Breast Cancer Treatment-Insight into the Molecular Mechanisms

Breast cancer (BC) is one of the most common malignancies in women. Although widespread successful synthetic drugs are available, natural compounds can also be considered as significant anticancer agents for treating BC. Some natural compounds have similar effects as synthetic drugs with fewer side effects on normal cells. Therefore, we aimed to unravel and analyze several molecular mechanisms of genistein (GNT) against BC. GNT is a type of dietary phytoestrogen included in the flavonoid group with a similar structure to estrogen that might provide a strong alternative and complementary medicine to existing chemotherapeutic drugs. Previous research reported that GNT could target the estrogen receptor (ER) human epidermal growth factor receptor-2 (HER2) and several signaling molecules against multiple BC cell lines and sensitize cancer cell lines to this compound when used at an optimal inhibitory concentration. More specifically, GNT mediates the anticancer mechanism through apoptosis induction, arresting the cell cycle, inhibiting angiogenesis and metastasis, mammosphere formation, and targeting and suppressing tumor growth factors. Furthermore, it acts via upregulating tumor suppressor genes and downregulating oncogenes in vitro and animal model studies. In addition, this phytochemical synergistically reverses the resistance mechanism of standard chemotherapeutic drugs, increasing their efficacy against BC. Overall, in this review, we discuss several molecular interactions of GNT with numerous cellular targets in the BC model and show its anticancer activities alone and synergistically. We conclude that GNT can have favorable therapeutic advantages when standard drugs are not available in the pharma markets.

Targeting Estrogens and Various Estrogen-Related Receptors against Non-Small Cell Lung Cancers: A Perspective

Non-small cell lung cancers (NSCLCs) account for ~85% of lung cancer cases worldwide. Mammalian lungs are exposed to both endogenous and exogenous estrogens. The expression of estrogen receptors (ERs) in lung cancer cells has evoked the necessity to evaluate the role of estrogens in the disease progression. Estrogens, specifically 17β-estradiol, promote maturation of several tissue types including lungs. Recent epidemiologic data indicate that women have a higher risk of lung adenocarcinoma, a type of NSCLC, when compared to men, independent of smoking status. Besides ERs, pulmonary tissues both in healthy physiology and in NSCLCs also express G-protein-coupled ERs (GPERs), epidermal growth factor receptor (EGFRs), estrogen-related receptors (ERRs) and orphan nuclear receptors. Premenopausal females between the ages of 15 and 50 years synthesize a large contingent of estrogens and are at a greater risk of developing NSCLCs. Estrogen-ER/GPER/EGFR/ERR-mediated activation of various cell signaling molecules regulates NSCLC cell proliferation, survival and apoptosis. This article sheds light on the most recent achievements in the elucidation of sequential biochemical events in estrogen-activated cell signaling pathways involved in NSCLC severity with insight into the mechanism of regulation by ERs/GPERs/EGFRs/ERRs. It further discusses the success of anti-estrogen therapies against NSCLCs.

Long-term hypogonadism diminishes the neuroprotective effects of dietary genistein in young adult ovariectomized rats after transient focal ischemia

Increasing age disproportionately increases the risk of stroke among women compared to men of similar age, especially after menopause. One of the reasons for this observation is a sharp drop in circulating estrogens. However, the timing of initiation of estrogen replacement after menopause is associated with mixed beneficial and detrimental effects, hence contributing to widespread mistrust of estrogen use. Agents including soy isoflavones are being assessed as viable alternatives to estrogen therapy. In this study, we hypothesized that the neuroprotective effects of genistein, a soy isoflavone are less sensitive to the length of hypogonadism in young adult ovariectomized rats following cerebral ischemia. We expected that long-term hypogonadism will worsen motor and cognitive function, increase post-stroke inflammation with no effect on the neuroprotection of genistein. We compared the effect of treatment with dietary genistein (GEN) on short-term (2 weeks) and long-term hypogonadism (12 weeks) in young adult ovariectomized Sprague-Dawley rats on sensorimotor function, cognition and inflammation after focal ischemia. Dorsal Silastic implant of 17β-estradiol (E2) was used as a control for hormone therapy. Long-term hypogonadism stroked rats performed worse than the short-term hypogonadism stroked rats on the motor and cognitive function tests. GEN did not improve neurological assessment and motor learning after either short-term or long-term hypogonadism. GEN improved cognitive flexibility after short-term hypogonadism but not after the long-term. Both GEN and E2 reduced tissue loss after short-term hypogonadism and reduced GFAP expression at the contralateral side of ischemia after long-term hypogonadism. The length of hypogonadism may differentially influence the neuroprotective effects of both GEN and E2 on the motor and cognitive functions in young adult rats.

Dietary syringic acid reduces fat mass in an ovariectomy-induced mouse model of obesity

OBJECTIVE

Postmenopausal women are at increased risk of metabolic diseases such as obesity and diabetes. Therefore, the chemoprevention of postmenopausal changes in health via dietary supplements is important. Syringic acid (SA) is a phenolic compound present in the fruit of the assai palm, Euterpe oleracea, and in the mycelium of the shiitake mushroom, Lentinula edodes. This compound shows no affinity for estrogen receptors and may exert disease-preventive effects. Reportedly, dietary SA ameliorates high-fat diet-induced obesity in mice; however, its effects on estrogen deficiency-induced obesity are still unclear. Therefore, in this study, we investigated whether and how dietary SA affects these factors in ovariectomized (OVX) mice.

METHODS

Ten-week-old OVX mice were fed SA-containing diets (100 mg/kg body weight/d) for 12 weeks. Their body weights, food intake, and uterus weights as well as other parameters were measured and comparisons were made with mice in the control group.

RESULTS

Dietary SA did not affect the body weight, food intake, or uterus weight of OVX mice over the study period; however, the SA-fed group showed lower fat mass (ie, visceral, subcutaneous, and total fat) than the OVX-control group (11.1 ± 3.3 vs. 8.3 ± 2.4, P < 0.05; 7.9 ± 1.1 vs. 5.9 ± 1.6, P < 0.05; 19.0 ± 4.2 vs. 14.1 ± 3.8, P < 0.05, respectively). Furthermore, blood analysis revealed that SA-treatment resulted in a dose-dependent decrease and increase in serum triglyceride (59.2 ± 8.3 vs. 43.9 ± 12.2 mg/dL P < 0.05) and adiponectin (7.7 ± 0.3 vs. 9.5 ± 0.6 μg/mL, P < 0.05) levels, respectively.

CONCLUSIONS

These results suggest that the SA diet improves lipid metabolism without affecting the uterus in OVX mice. Therefore, dietary SA has potential applicability for the prevention of postmenopausal obesity and type 2 diabetes.

Genistein: Dual Role in Women's Health

Advanced research in recent years has revealed the important role of nutrients in the protection of women's health and in the prevention of women's diseases. Genistein is a phytoestrogen that belongs to a class of compounds known as isoflavones, which structurally resemble endogenous estrogen. Genistein is most often consumed by humans via soybeans or soya products and is, as an auxiliary medicinal, used to treat women's diseases. In this review, we focused on analyzing the geographic distribution of soybean and soya product consumption, global serum concentrations of genistein, and its metabolism and bioactivity. We also explored genistein's dual effects in women's health through gathering, evaluating, and summarizing evidence from current in vivo and in vitro studies, clinical observations, and epidemiological surveys. The dose-dependent effects of genistein, especially when considering its metabolites and factors that vary by individuals, indicate that consumption of genistein may contribute to beneficial effects in women's health and disease prevention and treatment. However, consumption and exposure levels are nuanced because adverse effects have been observed at lower concentrations in in vitro models. Therefore, this points to the duplicity of genistein as a possible therapeutic agent in some instances and as an endocrine disruptor in others.

Novel polar AhR-active chemicals detected in sediments of an industrial area using effect-directed analysis based on in vitro bioassays with full-scan high resolution mass spectrometric screening

Studies investigating aryl hydrocarbon receptor (AhR)-active compounds in the environment typically focus on non- and mid-polar substances, such as PAHs; while, information on polar AhR agonists remains limited. Here, we identified polar AhR agonists in sediments collected from the inland creeks of an industrialized area (Lake Sihwa, Korea) using effect-directed analysis combined with full-scan screening analysis (FSA; using LC-QTOFMS). Strong AhR-mediated potencies were observed for the polar and latter fractions of RP-HPLC (F3.5-F3.8) from sediment organic extracts in the H4IIE-luc in vitro bioassays. FSA was performed on the corresponding fractions. Twenty-eight tentative AhR agonists were chosen using a five-step process. Toxicological confirmation using bioassay revealed that canrenone, rutaecarpine, ciprofloxacin, mepanipyrim, genistein, protopine, hydrocortisone, and medroxyprogesterone were significantly active. The relative potencies of these AhR-active compounds compared to that of benzo[a]pyrene ranged from 0.00002 to 2.0. Potency balance analysis showed that polar AhR agonists explained, on average, ~6% of total AhR-mediated potencies in samples. Some novel polar AhR agonists also exhibited endocrine-disrupting potentials capable of binding to estrogen and glucocorticoid receptors, as identified by QSAR modeling. In conclusion, the focused studies on distributions, sources, fate, and ecotoxicological effects of novel polar AhR agonists in the environment are necessary.

Antioxidant Therapy and Antioxidant-Related Bionanomaterials in Diabetic Wound Healing

Ulcers are a lower-extremity complication of diabetes with high recurrence rates. Oxidative stress has been identified as a key factor in impaired diabetic wound healing. Hyperglycemia induces an accumulation of intracellular reactive oxygen species (ROS) and advanced glycation end products, activation of intracellular metabolic pathways, such as the polyol pathway, and PKC signaling leading to suppression of antioxidant enzymes and compounds. Excessive and uncontrolled oxidative stress impairs the function of cells involved in the wound healing process, resulting in chronic non-healing wounds. Given the central role of oxidative stress in the pathology of diabetic ulcers, we performed a comprehensive review on the mechanism of oxidative stress in diabetic wound healing, focusing on the progress of antioxidant therapeutics. We summarize the antioxidant therapies proposed in the past 5 years for use in diabetic wound healing, including Nrf2- and NFκB-pathway-related antioxidant therapy, vitamins, enzymes, hormones, medicinal plants, and biological materials.

Natural Polyphenols in Metabolic Syndrome: Protective Mechanisms and Clinical Applications

Metabolic syndrome (MetS) is a chronic disease, including abdominal obesity, dyslipidemia, hyperglycemia, and hypertension. It should be noted that the occurrence of MetS is closely related to oxidative stress-induced mitochondrial dysfunction, ectopic fat accumulation, and the impairment of the antioxidant system, which in turn further aggravates the intracellular oxidative imbalance and inflammatory response. As enriched anti-inflammatory and antioxidant components in plants, natural polyphenols exhibit beneficial effects, including improving liver fat accumulation and dyslipidemia, reducing blood pressure. Hence, they are expected to be useful in the prevention and management of MetS. At present, epidemiological studies indicate a negative correlation between polyphenol intake and MetS incidence. In this review, we summarized and discussed the most promising natural polyphenols (including flavonoid and non-flavonoid drugs) in the precaution and treatment of MetS, including their anti-inflammatory and antioxidant properties, as well as their regulatory functions involved in glycolipid homeostasis.

Pleiotropic Effects of Isoflavones in Inflammation and Chronic Degenerative Diseases

Isoflavones are phytoestrogens of plant origin, mostly found in the members of the Fabaceae family, that exert beneficial effects in various degenerative disorders. Having high similarity to 17-β-estradiol, isoflavones can bind estrogen receptors, scavenge reactive oxygen species, activate various cellular signal transduction pathways and modulate growth and transcription factors, activities of enzymes, cytokines, and genes regulating cell proliferation and apoptosis. Due to their pleiotropic activities isoflavones might be considered as a natural alternative for the treatment of estrogen decrease-related conditions during menopause. This review will focus on the effects of isoflavones on inflammation and chronic degenerative diseases including cancer, metabolic, cardiovascular, neurodegenerative diseases, rheumatoid arthritis and adverse postmenopausal symptoms.

Neither soyfoods nor isoflavones warrant classification as endocrine disruptors: a technical review of the observational and clinical data

Soybeans are a rich source of isoflavones, which are classified as phytoestrogens. Despite numerous proposed benefits, isoflavones are often classified as endocrine disruptors, based primarily on animal studies. However, there are ample human data regarding the health effects of isoflavones. We conducted a technical review, systematically searching Medline, EMBASE, and the Cochrane Library (from inception through January 2021). We included clinical studies, observational studies, and systematic reviews and meta-analyses (SRMA) that examined the relationship between soy and/or isoflavone intake and endocrine-related endpoints. 417 reports (229 observational studies, 157 clinical studies and 32 SRMAs) met our eligibility criteria. The available evidence indicates that isoflavone intake does not adversely affect thyroid function. Adverse effects are also not seen on breast or endometrial tissue or estrogen levels in women, or testosterone or estrogen levels, or sperm or semen parameters in men. Although menstrual cycle length may be slightly increased, ovulation is not prevented. Limited insight could be gained about possible impacts of in utero isoflavone exposure, but the existing data are reassuring. Adverse effects of isoflavone intake were not identified in children, but limited research has been conducted. After extensive review, the evidence does not support classifying isoflavones as endocrine disruptors.

Hormesis Mediates Acquired Resilience: Using Plant-Derived Chemicals to Enhance Health

This review provides an assessment of hormesis, a highly conserved evolutionary dose-response adaptive strategy that leads to the development of acquired resilience within well-defined temporal windows. The hormetic-based acquired resilience has a central role in affecting healthy aging, slowing the onset and progression of numerous neurodegenerative and other age-related diseases, and reducing risks and damage due to heart attacks, stroke, and other serious conditions of public health and medical importance. The review provides the historical foundations of hormesis, its dose-response features, its capacity for generalization across biological models and endpoints measured, and its mechanistic foundations. The review also provides a focus on the adaptive features of hormesis, i.e., its capacity to upregulate acquired resilience and how this can be mediated by numerous plant-derived extracts, such as curcumin, ginseng, Ginkgo biloba, resveratrol, and green tea, that induce a broad spectrum of chemopreventive effects via hormesis.

Synthesis, characterization, and evaluation of BDDE crosslinked chitosan-TGA hydrogel encapsulated with genistein for vaginal atrophy

Vagina atrophy is a common symptom in women after menopause owing to decreasing estrogen levels. The most conventional treatment for this condition is estrogen cream. The shortcoming is its weak adhesion to the vagina mucus, thus requiring frequent daily application. In this study, BDDE was selected to crosslink and graft chitosan with thioglycolic acid, to form thiolated chitosan (CT) and improve the mucoadhesive properties of chitosan. Genistein was selected as the bioactive molecule that could exhibit estrogen-like properties for long-term treatment of vaginal atrophy. The efficacies of the materials were characterized and evaluated both in vitro and in vivo. Results showed that the mucoadhesive property of CT was approximately two-fold stronger against the constant flow than unmodified chitosan. CT with genistein (CT-G) was administered intravaginally every three days in vivo. It showed that the developed CT-G recover 54 % of the epithelium thickness of an atrophic vagina and ease vaginal atrophy.

Functional analysis of isoflavones using patient-derived human colonic organoids

Inflammatory bowel disease (IBD) comprises two major subtypes, ulcerative colitis (UC) and Crohn's disease, which are multifactorial diseases that may develop due to genetic susceptibility, dysbiosis, or environmental factors. Environmental triggers of IBD include food-borne factors, and a previous nationwide survey in Japan identified pre-illness consumption of isoflavones as a risk factor for UC. However, the precise mechanisms involved in the detrimental effects of isoflavones on the intestinal mucosa remain unclear. The present study employed human colonic organoids (hCOs) to investigate the functional effect of two representative isoflavones, genistein and daidzein, on human colonic epithelial cells. The addition of genistein to organoid reformation assays significantly decreased the number and size of reformed hCOs compared with control and daidzein treatment, indicating an inhibitory effect of genistein on colonic cell/progenitor cell function. Evaluation of the phosphorylation status of 49 different receptor tyrosine kinases showed that genistein selectively inhibited phosphorylation of epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (HGFR). We established a two-dimensional wound-repair model using hCOs and showed that genistein significantly delayed the overall wound-repair response. Our results collectively show that genistein may exert its detrimental effects on the intestinal mucosa via negative regulation of stem/progenitor cell function, possibly leading to sustained mucosal injury and the development of UC.

Daidzein modulates cocaine-reinforcing effects and cue-induced cocaine reinstatement in CD-1 male mice

RATIONALE

Cocaine addiction is a chronic relapsing disorder that lacks of an effective treatment. Isoflavones are a family of compounds present in different plants and vegetables like soybeans that share a common chemical structure. Previous studies have described that synthetic derivatives from the natural isoflavone daidzin can modulate cocaine addiction, by a mechanism suggested to involve aldehyde-dehydrogenase (ALDH) activities.

OBJECTIVES

Based on these previous studies, we investigated the effects of three natural isoflavones, daidzin, daidzein, and genistein, on the modulation of the cocaine reinforcing effects and on cue-induced reinstatement in an operant mouse model of cocaine self-administration.

RESULTS

Chronic treatment with daidzein or genistein decreased operant responding to obtain cocaine intravenous infusions. On the other hand, daidzein and daidzin, but not genistein, were effective in decreasing cue-induced cocaine reinstatement. Complementary studies revealed that daidzein effects on cocaine reinforcement were mediated through a mechanism that involved dopamine type-2/3 receptors (DA-D2/3) activities.

CONCLUSIONS

Our results suggest that these natural compounds alone or in combination can be a potential therapeutic approach for cocaine addiction. Further clinical studies are required in order to ascertain their potential therapeutic use.

Nutraceuticals in the Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a severe disease characterized by the loss and obstructive remodeling of the pulmonary arterial wall, causing a rise in pulmonary arterial pressure and pulmonary vascular resistance, which is responsible for right heart failure, functional decline, and death. Although many drugs are available for the treatment of this condition, it continues to be life-threatening, and its long-term treatment is expensive. On the other hand, many natural compounds present in food have beneficial effects on several cardiovascular conditions. Several studies have explored many of the potential beneficial effects of natural plant products on PAH. However, the mechanisms by which natural products, such as nutraceuticals, exert protective and therapeutic effects on PAH are not fully understood. In this review, we analyze the current knowledge on nutraceuticals and their potential use in the protection and treatment of PAH, as well as whether nutraceuticals could enhance the effects of drugs used in PAH through similar mechanisms.

Gene X environment: the cellular environment governs the transcriptional response to environmental chemicals

Background

An individual’s response to environmental exposures varies depending on their genotype, which has been termed the gene-environment interaction. The phenotype of cell exposed can also be a key determinant in the response to physiological cues, indicating that a cell-gene-environment interaction may exist. We investigated whether the cellular environment could alter the transcriptional response to environmental chemicals. Publicly available gene expression array data permitted a targeted comparison of the transcriptional response to a unique subclass of environmental chemicals that alter the activity of the estrogen receptor, xenoestrogens.

Results

Thirty xenoestrogens were included in the analysis, for which 426 human gene expression studies were identified. Comparisons were made for studies that met the predefined criteria for exposure length, concentration, and experimental replicates. The cellular response to the phytoestrogen genistein resulted in remarkably unique transcriptional profiles in breast, liver, and uterine cell-types. Analysis of gene regulatory networks and molecular pathways revealed that the cellular context mediated the activation or repression of functions important to cellular organization and survival, including opposing effects by genistein in breast vs. liver and uterine cell-types. When controlling for cell-type, xenoestrogens regulate unique gene networks and biological functions, despite belonging to the same class of environmental chemicals. Interestingly, the genetic sex of the cell-type also strongly influenced the transcriptional response to xenoestrogens in the liver, with only 22% of the genes significantly regulated by genistein common between male and female cells.

Conclusions

Our results demonstrate that the transcriptional response to environmental chemicals depends on a variety of factors, including the cellular context, the genetic sex of a cell, and the individual chemical. These findings highlight the importance of evaluating the impact of exposure across cell-types, as the effect is responsive to the cellular environment. These comparative genetic results support the concept of a cell-gene-environment interaction.

The association between soy isoflavone intake and menopausal symptoms after breast cancer diagnosis: a prospective longitudinal cohort study on Chinese breast cancer patients

PURPOSE

This study investigated the association between soy isoflavone intake and menopausal symptoms (MPS) among Chinese women with early stage breast cancer in a prospective cohort study.

METHODS

In an on-going prospective cohort study that involved 1462 Chinese women with early stage breast cancer, MPS were assessed at 18, 36 and 60 months after cancer diagnosis using the validated menopausal rating scale (MRS) questionnaire. Daily soy food intake for the previous 12 months was assessed at the same time using a validated food frequency questionnaire. The associations between MPS and soy isoflavone intake were evaluated in multivariable logistic regression analyses.

RESULTS

The prevalence of MPS was almost the same during the first 60 months after cancer diagnosis, which were 64.5%, 65.2%, and 63.9% at 18, 36, and 60 months, respectively. Patients with MPS tended to be younger than those without MPS. The intake of soy isoflavones was not associated with the total score of MRS at 18-month follow-up [highest vs lowest tertile, odds ratio (OR) = 1.00, 95% CI 0.75-1.34]. Similarly, no significant association was noted at 36-month (OR = 1.25, 95% CI 0.92-1.69) and 60-month (OR = 1.21, 95% CI 0.84-1.74) follow-up. With regards to specific domain within MRS, the risk of symptoms presenting in somatic domain was higher among breast cancer patients who were in the highest tertile of soy isoflavone intake at 36 months post-diagnosis (OR = 1.44, 95% CI 1.07-1.94, P-trend = 0.02), compared with the lowest tertile, where a stronger significant association was noted among patients who were younger than 60 years (OR = 1.52, 95% CI 1.05-2.20, P-trend = 0.03) and pre-menopausal (OR = 3.81, 95% CI 1.85-8.11, P-trend < 0.01).

CONCLUSION

The present study provided further evidence that soy isoflavone consumption was not associated with MPS among Chinese breast cancer patients. In fact, patients with higher intake of soy isoflavone have increased risk of experiencing somatic symptoms.

The Cytotoxic Effect of Genistein, a Soybean Isoflavone, against Cultured Tribolium Cells

The red flour beetle Tribolium castaneum is a known pest of various grains and stored-products such as wheat flours; however, T. castaneum feeds on and infests soybean and soy products. For more than 60 years, soy flour has been suggested to be unstable food for Tribolium spp. because it causes larval development failure. However, it remains unknown whether soy flour affects adult beetles. The objective of the present study was to examine the effects of soy flour and its related isoflavones against T. castaneum using an artificial dietary intake assay. Beetles were fed gypsum (a non-digestible compound) mixed with either water (control) or soy flour. Significantly fewer beetles survived after being fed the soy flour treatment. Although the soy isoflavone genistein, a defensive agent and secondary metabolite, decreased the T. castaneum adult survival, it required a long time to have a lethal effect. Therefore, the cytotoxic effects of soy flour, i.e., the rapid biological responses following isoflavone addition, were also examined using a cultured cell line derived from T. castaneum. Both genistin and genistein significantly affected the survival of the cultured cells, although genistein had a stronger lethal effect. This study demonstrated the toxicity of genistein found in soybean against T. castaneum cultured cells within 24 h period. Genistein may be used as an oral toxin biopesticide against T. castaneum.

Biphasic Dose-Response Induced by Phytochemicals: Experimental Evidence

Many phytochemicals demonstrate nonmonotonic dose/concentration-response termed biphasic dose-response and are considered to be hormetic compounds, i.e., they induce biologically opposite effects at different doses. In numerous articles the hormetic nature of phytochemicals is declared, however, no experimental evidence is provided. Our aim was to present the overview of the reports in which phytochemical-induced biphasic dose-response is experimentally proven. Hence, we included in the current review only articles in which the reversal of response between low and high doses/concentrations of phytochemicals for a single endpoint was documented. The majority of data on biphasic dose-response have been found for phytoestrogens; other reports described these types of effects for resveratrol, sulforaphane, and natural compounds from various chemical classes such as isoquinoline alkaloid berberine, polyacetylenes falcarinol and falcarindiol, prenylated pterocarpan glyceollin1, naphthoquinones plumbagin and naphazarin, and panaxatriol saponins. The prevailing part of the studies presented in the current review was performed on cell cultures. The most common endpoint tested was a proliferation of tumor and non-cancerous cells. Very few experiments demonstrating biphasic dose-response induced by phytochemicals were carried out on animal models. Data on the biphasic dose-response of various endpoints to phytochemicals may have a potential therapeutic or preventive implication.

Genistein inhibits proliferation and induces senescence in neonatal mouse pituitary gland explant cultures

Genistein is an isoflavone abundant in soybean and infants are exposed to high levels of genistein in soy-based formula. It is known that genistein mediates estrogen receptor (ER) signaling, and exposure during neonatal development could cause acute and long term endocrine effects. We assayed genistein's impact on the neonatal mouse pituitary gland because it is an endocrine signaling hub and is sensitive to endocrine disruption during critical periods. Pituitary explant cultures, which actively proliferate and differentiate, were exposed to 0.06 μM-36 μM genistein and assayed for mRNA and protein changes. Genistein induced mRNA expression of the ERα regulated gene, Cckar, to the same magnitude as estradiol (E2) but with less potency. Interestingly, 36 μM genistein strongly inhibited pituitary proliferation, measured by a reduction in mKi67 mRNA and phospho-Histone H3 immunostaining. Examining cell cycle dynamics, we found that 36 μM genistein decreased Ccnb1 (Cyclin B1) mRNA; while mRNA for the cyclin dependent kinase inhibitor Cdkn1a (p21) was upregulated, correlated with an apparent increase in p21 immunostained cells. Strikingly, we observed a robust onset of cellular senescence, permanent cell cycle exit, in 36 μM genistein treated pituitaries by increased senescence activated β-galactosidase staining. We also found that 36 μM genistein decreased Bcl2 mRNA levels, a gene protective against apoptosis. Taken together these data suggest that genistein exposure during the neonatal period could initiate senescence and halt proliferation during a time when the proper numbers of endocrine cells are being established for mature gland function.

Interactions between plant-derived oestrogenic substances and the mycoestrogen zearalenone in a bioassay with MCF-7 cells

Human and animal diets may contain several non-steroidal oestrogenic compounds which originate either from plants (phytoestrogens) or from fungi that infect plants (mycoestrogens such as zearalenone (ZEN)). Phytoestrogens may compete with ZEN in binding to the oestrogen receptor β and thereby may counteract the oestrogenic activity of ZEN. Using a modified version of the E-screen assay, plant-derived oestrogenic substances were tested for their proliferative or anti-proliferative effect on oestrogen-dependent MCF-7 cells. The samples were additionally tested for their ability to influence the oestrogenic activity of ZEN (1 μM). Among the individual substances tested, 8-prenylnaringenin had the strongest effect, as cell proliferation was increased by 78% at the lowest concentration (0.23 μM), and by 167% at the highest concentration (29.4 μM). Coumestrol (5.83 μM) increased cell proliferation by 39%, and genistein (370 μM) by 61%, respectively. Xanthohumol and enterolactone did not stimulate cell proliferation significantly. In the co-incubation experiments with ZEN, none of the single substances was able to decrease the oestrogenic activity of ZEN. Only for 8-prenylnaringenin (14.7 and 29.4 μM) was a trend towards an increase in the ZEN-induced cell proliferation up to 72% observed. In conclusion, with the exception of 8-prenylnaringenin, no substantial interaction between phytoestrogens and the mycotoxin ZEN could be detected using a bioassays with MCF-7 cells.

Anti-osteoporotic effects of syringic acid and vanilic acid in the extracts of waste beds after mushroom cultivation

In recent years, the number of patients with osteoporosis has increased as population grows older. Therefore, the chemoprevention of osteoporosis by better nutrition is important. White-rot fungi degrades milled wood lignin for growth and development. This degradation results in the formation of phenolic compounds such as syringic acid (SA) and vanillic acid (VA). In the artificial culture of edible mushrooms using a mushroom bed, the disposal of waste beds after mushroom cultivation is an important issue. The present study investigated the presence and amount of both SA and VA in the discarded waste beds after mushroom cultivation. The extracts from waste beds after cultivation of shiitake mushrooms, Lentinula edodes; buna shimeji, Hypsizygus marmoreus; maitake, Grifola frondosa; king trumpet mushrooms, Pleurotus eryngii; and butterscotch mushrooms, Pholiota microspora were analyzed using high performance liquid chromatography. Although the content of SA and VA was considerably different among the mushrooms, SA and VA were present in extracts obtained from all the waste beds. We also demonstrated that SA and VA exert their anti-osteoporotic effect independently of the estrogen receptor-mediated pathway using murine monocytic RAW264.7 cells, ovariectomized mice, and human breast cancer MCF-7 cells. Thus, these results suggest that the extracts are effective sources of SA and VA, which are effective in preventing osteoporosis.

Disruption of oocyte maturation by selected environmental chemicals in zebrafish

Oocyte maturation can be a target of endocrine disruption by environmental chemicals capable of acting as hormone mimics, receptor blockers, and/or enzyme inhibitors. Six environmental chemicals (genistein, endosulfan, malathion, iprodione, carbaryl, and glyphosate) were selected to determine their ability to interfere with oocyte maturation in zebrafish. The translucent oocytes undergoing germinal vesicle (nucleus) breakdown (GVBD) were counted and expressed as a ratio of oocytes undergoing GVBD and total oocytes exposed. The GVBD increased significantly in oocytes exposed to 10 IU/ml to 100 IU/ml human chorionic gonadotropin (hCG). The lowest effective concentration of genistein that inhibited hCG-induced GVBD was 30 μM, while endosulfan inhibited it at 0.03 μM concentration. In addition, malathion inhibited hCG-induced GVBD at the lowest concentration of 60 μM. These inhibitory effects were likely due to the chemicals acting as estrogen mimics, induction of estrogen receptors, or increase in aromatase activity resulting in enhanced estrogen action. Fungicide iprodione, possibly acting as a progestin mimic, promoted hCG-induced GVBD at the lowest concentration of 20 μM, while the weed killer glyphosate inhibited hCG-induced GVBD starting at the 50 μM concentration. These results demonstrate the feasibility of using fully grown zebrafish oocytes arrested at the prophase I stage in an in vitro incubation system to evaluate the effects of a variety of environmental chemicals on oocyte maturation.

The effects of dietary levels of genistein on ovarian follicle number and gene expression

Genistein is a phytoestrogen found in soy. We previously found that adult exposure to dietary levels of genistein affected gestation time, parturition time, litter size, pup weight, and pup mortality in CD-1 mice. The present study investigated the effects of adult genistein exposure on follicle number and gene expression in the ovaries of CD-1 mice. We found that exposure to genistein had no effect on follicle number, but it did affect the expression of apoptotic regulatory genes (Bax, Bcl-2, Bid, and Dffa) in the ovary.

Neonatal Genistein Exposure and Glucocorticoid Signaling in the Adult Mouse Uterus

BACKGROUND

Female reproductive tract development is sensitive to the endocrine-disrupting potential of environmental estrogens. Early-life exposure to the dietary phytoestrogen genistein impairs fertility and persistently alters the transcriptome in the oviduct and uterus of rodents. Glucocorticoid signaling, which has recently been shown to be essential for normal fertility in the female mouse uterus, is antagonized by genistein.

OBJECTIVE

Our goal was to determine whether early-life exposure to genistein disrupts glucocorticoid signaling in the mouse uterus, which may contribute to infertility.

METHODS

Female C57Bl/6 mice were exposed to either 50 mg/kg per day genistein, 10 μg/kg per day estradiol, or vehicle (corn oil) on postnatal days 1-5 (PND1-5), and then treated with the synthetic glucocorticoid dexamethasone (Dex: 1 mg/kg) or vehicle (saline) on PND5, at weaning on PND21, or as adults on PND56 following adrenalectomy and ovariectomy to evaluate glucocorticoid responsiveness. Uteri were isolated following treatment for gene expression or chromatin immunoprecipitation.

RESULTS

Neonatal exposure to genistein altered the uterine transcriptome of adult mice and caused substantial changes to the transcriptional response to glucocorticoids. Although expression of the glucocorticoid receptor was not affected, genistein exposure disrupted glucocorticoid receptor recruitment to specific regulatory sites in target genes. Many genes involved in chromatin remodeling were dysregulated in genistein-exposed mice, suggesting that epigenetic reprograming may contribute to the altered glucocorticoid response of the uterus following early-life exposure to genistein. These changes affected the biological activity of glucocorticoids within the uterus, as glucocorticoids antagonized the proliferative effects of estradiol in the uterus of control mice but not genistein-exposed mice.

CONCLUSIONS

Our findings suggest that disruption of glucocorticoid signaling due to early-life exposure to environmental estrogens may in part render the uterus unable to support implantation. https://doi.org/10.1289/EHP1575.

Evidence for interactions between homocysteine and genistein: insights into stroke risk and potential treatment

Elevated plasma homocysteine (2-amino-4-sulfanylbutanoic acid) level is a risk factor for stroke. Moreover, it has been suggested that high levels of homocysteine in the acute phase of an ischemic stroke can predict mortality, especially in stroke patients with the large-vessel atherosclerosis subtype. In clinical studies, supplementation with genistein (5, 7-dihydroxy-3- (4-hydroxyphenyl)-4H-1-benzopyran-4-one) decreased plasma homocysteine levels considerably. Therefore, genistein could be considered as a potential drug for prevention and/or treatment of stroke. However, the mechanism of the effect of genistein on homocysteine level remains to be elucidated. In this report, direct functional interactions between homocysteine and genistein are demonstrated in in vitro experimental systems for determination of methylenetetrahydrofolate reductase (MetF) and glutathione peroxidase (GPx) activities, reconstructed with purified compounds, and in a simple in vivo system, based on measurement of growth rate of Vibrio harveyi and Bacillus subtilis cultures. Results of molecular modelling indicated that homocysteine can directly interact with genistein. Therefore, genistein-mediated decrease in plasma levels of homocysteine, and alleviation of biochemical and physiological effects of one of these compounds by another, might be ascribed to formation of homocysteine-genistein complexes in which biological activities of these molecules are abolished or alleviated.

Genistein inhibits the S-phase kinase-associated protein 2 expression in breast cancer cells

Breast cancer is one of the most lethal cancers affecting women worldwide and was estimated to account for ~30% of all new cancer diagnoses in women. Although available evidence has proved the tumor suppressor role of genistein in cancer, the underling mechanisms have remained to be fully elucidated. S-phase kinase-associated protein 2 (Skp2) has been revealed to critically enhance the pathogenesis of multiple human cancers. The present study determined whether genistein exerts its anti-tumor function by suppressing Skp2 in breast cancer cells. Genistein significantly inhibited the proliferation, invasion and migration of breast cancer cells. Furthermore, genistein treatment also induced marked apoptosis and a typical cell cycle arrest in G2/M phase. Mechanistically, genistein treatment was identified to cause a significant downregulation of Skp2. Two crucial tumor suppressors, p21 and p27, were upregulated in genistein-treated breast cancer cells. The present results revealed that genistein exerted its tumor suppressor effect at least partially via inhibition of Skp2 and promotion of its downstream targets p21 and p27. Therefore, inactivation of Skp2 by genistein may be a promising approach for breast cancer treatment.

Genistein protects hippocampal neurons against injury by regulating calcium/calmodulin dependent protein kinase IV protein levels in Alzheimer's disease model rats

Genistein has a neuroprotective effect in Alzheimer's disease, but its mechanism of action needs further clarification. Accumulating evidence suggests that excessive phosphorylation of tau protein causes production of neurofibrillary tangles, which is one of the main pathological characteristics of Alzheimer's disease, and tau protein can be phosphorylated by calcium/calmodulin dependent protein kinase IV (CAMK4). After 7 days of pre-administration of genistein (90 mg/kg), an Alzheimer's disease rat model was established using an intraperitoneal injection of D-galactose combined with an intracerebral injection of amyloid-β peptide (25-35). The rat was then continuously administered genistein (90 mg/kg) for 42 days. The Morris water maze test, western blotting and hematoxylin-eosin staining results showed that genistein significantly decreased the escape latency and increased the number of times crossing the platform, reduced p-tau, CALM, CAMKK1 and p-CAMK4 protein levels in the hippocampus, and alleviated hippocampal neuron damage. These findings indicate that genistein may play a neuroprotective role in Alzheimer's disease through regulating CAMK4 to modulate tau hyperphosphorylation.

In vitro-in silico-based analysis of the dose-dependent in vivo oestrogenicity of the soy phytoestrogen genistein in humans

BACKGROUND AND PURPOSE

The in vivo oestrogenicity of genistein and its glycoside genistin is still under debate. The present study aimed to develop a physiologically based kinetic (PBK) model that provides insight in dose-dependent plasma concentrations of genistein aglycone and its metabolites and enables prediction of in vivo oestrogenic effective dose levels of genistein and genistin in humans.

EXPERIMENTAL APPROACH

A PBK model for genistein and genistin in humans was developed based on in vitro metabolic parameters. The model obtained was used to translate in vitro oestrogenic concentration-response curves of genistein to in vivo oestrogenic dose-response curves for intake of genistein and genistin.

KEY RESULTS

The model predicted that genistein-7-O-glucuronide was the major circulating metabolite and that levels of the free aglycone were generally low [0.5-17% of total plasma genistein at oral doses from 0.01 to 50 mg (kg·bw)^-1 ]. The predicted in vivo benchmark dose for 5% response values for oestrogenicity varied between 0.06 and 4.39 mg kg^-1 genistein. For genistin, these values were 1.3-fold higher. These values are in line with reported human data and show that oestrogenic responses can be expected at an Asian dietary and a supplementary intake, while intake resulting from a Western diet may not be effective.

CONCLUSIONS AND IMPLICATIONS

The present study shows how plasma concentrations of genistein and its metabolites and oestrogenic dose levels of genistein in humans can be predicted by combining in vitro oestrogenicity with PBK model-based reverse dosimetry, eliminating the need for human intervention studies.

Phytochemicals Targeting Estrogen Receptors: Beneficial Rather Than Adverse Effects?

In mammals, the effects of estrogen are mainly mediated by two different estrogen receptors, ERα and ERβ. These proteins are members of the nuclear receptor family, characterized by distinct structural and functional domains, and participate in the regulation of different biological processes, including cell growth, survival and differentiation. The two estrogen receptor (ER) subtypes are generated from two distinct genes and have partially distinct expression patterns. Their activities are modulated differently by a range of natural and synthetic ligands. Some of these ligands show agonistic or antagonistic effects depending on ER subtype and are described as selective ER modulators (SERMs). Accordingly, a few phytochemicals, called phytoestrogens, which are synthesized from plants and vegetables, show low estrogenic activity or anti-estrogenic activity with potentially anti-proliferative effects that offer nutraceutical or pharmacological advantages. These compounds may be used as hormonal substitutes or as complements in breast cancer treatments. In this review, we discuss and summarize the in vitro and in vivo effects of certain phytoestrogens and their potential roles in the interaction with estrogen receptors.

Genistein modulation of seizure: involvement of estrogen and serotonin receptors

Genistein, a major source of phytoestrogen exposure for humans and animals, has been shown to mediate neuroprotection in Alzheimer's disease and status epilepticus. In the present study, we investigated the effect of genistein on pentylenetetrazole-induced seizures in ovariectomized mice and the possible involvement of estrogenic and serotonergic pathways in the probable effects of genistein. Intraperitoneal (i.p.) administration of genistein (10 mg/kg) significantly increased the seizure threshold 30 min prior to induction of seizures 14 days after ovariectomy surgery. Administration of fulvestrant (1 mg/kg, i.p.), an estrogen receptor antagonist, completely reversed the anticonvulsant effect of genistein (10 mg/kg) in ovariectomized mice. Administration of the antagonist of serotonin receptor (5-HT3), tropisetron (10 mg/kg, i.p.), eliminated the anticonvulsant effect of genistein, whereas co-administration of m-chlorophenylbiguanide (5-HT3 receptor agonist; 1 mg/kg) and a non-effective dose of genistein (5 mg/kg) increased the seizure threshold. To conclude, it seems that estrogenic/serotonergic systems might be involved in the anticonvulsant properties of genistein.

Genistein treatment improves fracture resistance in obese diabetic mice

BACKGROUND

Obese, type two diabetics are at an increased risk for fracturing their limb bones in comparison to the general population. Phytoestrogens like as the soy isoflavone genistein have been shown to protect against bone loss. In this study, we tested the effects of genistein treatment on femurs of ob/ob mice, a model for obesity and type two diabetes mellitus.

METHODS

Twenty six-week-old female mice were divided into obese (ob/ob) control, obese genistein-treated, lean (ob/+) control, and lean genistein-treated groups (n = 5 each). Treatment with genistein consisted of 600 mg genistein/kg diet. Control mice were given standard rodent chow. At the end of a four-week treatment period, bone histomorphometric and three-point bending properties were compared among groups.

RESULTS

Obese mice had larger bone areas (B.Ar.; P < 0.05) and total areas (Tt.Ar.; P < 0.05), but similar bone volume (B.Ar./Tt.Ar.; P > 0.05) of the proximal femoral epiphysis in comparison to lean mice. Treatment with genistein decreased Tt.Ar. and femur length, and increased ultimate force required to fracture the femur and the maximum deformation to failure (P < 0.05).

CONCLUSIONS

Genistein improves resistance to fracture from bending loads.

Molecular and Therapeutic Targets of Genistein in Alzheimer's Disease

Alzheimer's disease (AD) is a devastating brain disorder characterized by an increased level of amyloid-beta (Aβ) peptide deposition and neuronal cell death leading to an impairment of learning and thinking skills. The Aβ deposition is a key factor in senile plaques of the AD brain which cause the elevation of intracellular calcium ions and the production of formidable free radicals, both of which greatly contribute to the AD-associated cascade, leading to unstoppable neuronal loss in the hippocampal region of the brain. Natural products are currently considered as an alternative strategy for the discovery of novel multipotent drugs against AD. They include the naturally occurring dietary soy isoflavone genistein which has been recognized to possess several health-promoting effects. Genistein has been mainly focused because of its potential on amelioration of Aβ-induced impairment and its antioxidant capacity to scavenge the free radicals produced in AD. It can also directly interact with the targeted signaling proteins and stabilize their activity to prevent AD. An improved understanding of the direct interactions between genistein and target proteins would contribute to the further development of AD treatment. This review mainly focuses on molecular targets and the therapeutic effects regulated by genistein, which has the ability to directly target the Aβ peptide and to control its activity involved in intracellular signaling pathways, which otherwise would lead to neuronal death in the hippocampal region of the AD brain.

The Anti-Cancer Effect of Polyphenols against Breast Cancer and Cancer Stem Cells: Molecular Mechanisms

The high incidence of breast cancer in developed and developing countries, and its correlation to cancer-related deaths, has prompted concerned scientists to discover novel alternatives to deal with this challenge. In this review, we will provide a brief overview of polyphenol structures and classifications, as well as on the carcinogenic process. The biology of breast cancer cells will also be discussed. The molecular mechanisms involved in the anti-cancer activities of numerous polyphenols, against a wide range of breast cancer cells, in vitro and in vivo, will be explained in detail. The interplay between autophagy and apoptosis in the anti-cancer activity of polyphenols will also be highlighted. In addition, the potential of polyphenols to target cancer stem cells (CSCs) via various mechanisms will be explained. Recently, the use of natural products as chemotherapeutics and chemopreventive drugs to overcome the side effects and resistance that arise from using chemical-based agents has garnered the attention of the scientific community. Polyphenol research is considered a promising field in the treatment and prevention of breast cancer.

The Impact of Soy Isoflavones on MCF-7 and MDA-MB-231 Breast Cancer Cells Using a Global Metabolomic Approach

Despite substantial research, the understanding of the chemopreventive mechanisms of soy isoflavones remains challenging. Promising tools, such as metabolomics, can provide now a deeper insight into their biochemical mechanisms. The purpose of this study was to offer a comprehensive assessment of the metabolic alterations induced by genistein, daidzein and a soy seed extract on estrogen responsive (MCF-7) and estrogen non-responsive breast cancer cells (MDA-MB-231), using a global metabolomic approach. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that all test compounds induced a biphasic effect on MCF-7 cells and only a dose-dependent inhibitory effect on MDA-MB-231 cells. Proton nuclear magnetic resonance (¹H-NMR) profiling of extracellular metabolites and gas chromatography-mass spectrometry (GC-MS) profiling of intracellular metabolites confirmed that all test compounds shared similar metabolic mechanisms. Exposing MCF-7 cells to stimulatory concentrations of isoflavones led to increased intracellular levels of 6-phosphogluconate and ribose 5-phosphate, suggesting a possible upregulation of the pentose phosphate pathway. After exposure to inhibitory doses of isoflavones, a significant decrease in glucose uptake was observed, especially for MCF-7 cells. In MDA-MB-231 cells, the glutamine uptake was significantly restricted, leading to alterations in protein biosynthesis. Understanding the metabolomic alterations of isoflavones represents a step forward in considering soy and soy derivates as functional foods in breast cancer chemoprevention.