Long-Term Exposure to Isoflavones Alters the Hormonal Steroid Homeostasis-Impairing Reproductive Function in Adult Male Wistar Rats.

The consumption of isoflavones is gaining popularity worldwide due to their beneficial effects on health. However, isoflavones are considered to be endocrine disruptors and cause deleterious effects on hormone-sensitive organs, especially in males. Therefore, this study aimed to determine if a continuous and prolonged exposure to isoflavones in adult males altered the endocrine axis effect of testicular function. For this purpose, seventy-five adult male rats were administered with low and high mixtures of isoflavones (genistein and daidzein) for 5 months. The determination of steroid hormones (progesterone, androstenedione, dehydroepiandrosterone, testosterone, dihydrotestosterone, 17ß-estradiol, and estrone sulphate) was carried out in serum and testicular homogenate samples. Sperm quality parameters and testicular histology were also determined. The results revealed that low and high doses of isoflavones promote a hormonal imbalance in androgen and estrogen production, resulting in a decrease in circulating and testicular androgen levels and an increase in estrogen levels. These results are associated with a reduction in the sperm quality parameters and a reduction in the testicular weight, both in the diameter of the seminiferous tubules and the height of the germinal epithelium. Altogether, these results suggest that a continuous exposure to isoflavones in adult male rats causes a hormonal imbalance in the testes that disrupts the endocrine axis, causing defects in testicular function.

Puerarin protects against sepsis-associated encephalopathy by inhibiting NLRP3/Caspase-1/GSDMD pyroptosis pathway and reducing blood-brain barrier damage.

Puerarin (Pue), an isoflavone compound extracted from Pueraria, has been shown to inhibit inflammation and reduce cerebral edema. The neuroprotective effect of puerarin has attracted much attention in recent years. Sepsis-associated encephalopathy (SAE) is a serious complication of sepsis that causes damage to the nervous system. This study aimed to investigate the effect of puerarin on SAE and elucidate the potential underlying mechanisms. A rat model of SAE was established by cecal ligation and puncture, and puerarin was injected intraperitoneally immediately after the operation. Puerarin was found to improve the survival rate and neurobehavioral score of SAE rats, alleviate symptoms, inhibit the level of brain injury markers NSE and S100ß, and improve the pathological changes in rat brain tissue. Puerarin was also found to inhibit the level of factors related to the classical pathway of pyroptosis, such as NLRP3, Caspase-1, GSDMD, ASC, IL-1ß, and IL-18. Puerarin also reduced the brain water content and penetration of Evan's Blue dye in SAE rats, and reduced the expression of MMP-9. In the in vitro experiments, we further confirmed the inhibitory effect of puerarin on neuronal pyroptosis by establishing a pyroptosis model in HT22 cells. Our findings suggest that puerarin may improve SAE by inhibiting the classical pathway of NLRP3/Caspase-1/GSDMD-mediated pyroptosis and reducing blood-brain barrier damage, thus playing a role in brain protection. Our study may provide a novel therapeutic strategy for SAE.

Natural isoflavone formononetin inhibits IgE-mediated mast cell activation and allergic inflammation by increasing IgE receptor degradation.

Immunoglobulin (Ig)E-associated mast cell (MC) activation triggers pro-inflammatory signals that underlie type I allergic diseases. Here, we examined the effects of the natural isoflavone formononetin (FNT) on IgE-mediated MC activation and associated mechanisms of high-affinity IgE receptor (FcεRI) signal inhibition. The effects of FNT on the mRNA expression of inflammatory factors, release of histamine and ß-hexosaminidase (ß-hex), and expression of signaling proteins and ubiquitin (Ub)-specific proteases (USPs) were analyzed in two sensitized/stimulated MC lines. FcεRIγ-USP interactions were detected by co-immunoprecipitation (IP). FNT dose-dependently inhibited ß-hex activity, histamine release, and inflammatory cytokine expression in FcεRI-activated MCs. FNT suppressed IgE-induced NF-κB and MAPK activity in MCs. The oral administration of FNT attenuated passive cutaneous anaphylaxis (PCA) reactions and ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) reactions in mice. FNT reduced the FcεRIγ chain expression, via increased proteasome-mediated degradation, and induced FcεRIγ ubiquitination by inhibiting USP5 and/or USP13. FNT and USP inhibition may be useful for suppressing IgE-mediated allergic diseases.

[Soybean isoflavones alleviate cerebral ischemia/reperfusion injury in rats by inhibiting ferroptosis and inflammatory cascade reaction].

OBJECTIVE: To explore the mechanism that mediates the effect of soybean isoflavones (SI) against cerebral ischemia/reperfusion (I/R) injury in light of the regulation of regional cerebral blood flow (rCBF), ferroptosis, inflammatory response and blood-brain barrier (BBB) permeability. METHODS: A total of 120 male SD rats were equally randomized into sham-operated group (Sham group), cerebral I/R injury group and SI pretreatment group (SI group). Focal cerebral I/R injury was induced in the latter two groups using a modified monofilament occlusion technique, and the intraoperative changes of real-time cerebral cortex blood flow were monitored using a laser Doppler flowmeter (LDF). The postoperative changes of cerebral pathological morphology and the ultrastructure of the neurons and the BBB were observed with optical and transmission electron microscopy. The neurological deficits of the rats was assessed, and the severities of cerebral infarction, brain edema and BBB disruption were quantified. The contents of Fe2+, GSH, MDA and MPO in the ischemic penumbra were determined with spectrophotometric tests. Serum levels of TNF-α and IL-1ßwere analyzed using ELISA, and the expressions of GPX4, MMP-9 and occludin around the lesion were detected with Western blotting and immunohistochemistry. RESULTS: The rCBF was sharply reduced in the rats in I/R group and SI group after successful insertion of the monofilament. Compared with those in Sham group, the rats in I/R group showed significantly increased neurological deficit scores, cerebral infarction volume, brain water content and Evans blue permeability (P < 0.01), decreased Fe2+ level, increased MDA level, decreased GSH content and GPX4 expression (P < 0.01), increased MPO content and serum levels of TNF-α and IL-1ß (P < 0.01), increased MMP-9 expression and lowered occludin expression (P < 0.01). All these changes were significantly ameliorated in rats pretreated with IS prior to I/R injury (P < 0.05 or 0.01). CONCLUSION: SI preconditioning reduces cerebral I/R injury in rats possibly by improving rCBF, inhibiting ferroptosis and inflammatory response and protecting the BBB.

Irigenin attenuates lipopolysaccharide-induced acute lung injury by inactivating the mitogen-activated protein kinase (MAPK) signaling pathway.

Acute lung injury (ALI) is a serious pulmonary inflammation disease with high mortality. Irigenin, an isoflavone from rhizomes of the Belamcanda chinensis, has been reported to exert anti-inflammatory, anti-oxidative, and anti-apoptotic activities in several diseases. However, it is still unclear whether irigenin can exert a beneficial effect in ALI. A network pharmacology method was utilized to predict the hub targets and potential therapeutic mechanisms of irigenin against ALI. Lipopolysaccharide (LPS) was used to establish the mice model of ALI for evaluating the effects of irigenin. According to the protein-protein interaction (PPI) network, we identified EGFR, HRAS, AKT1, SRC, and HSP90AA1 as the top five significant genes. Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment assays showed that irigenin might affect inflammatory response, cytokine production, and cell death by the mitogen-activated protein kinase (MAPK) signaling pathway. In vivo experiment results manifested that irigenin decreased pathological changes, lung Wet/Dry weight ratio, and total protein content in bronchoalveolar lavage fluid (BALF). Irigenin also reduced the production of inflammatory cytokines, including tumor necrosis factor-a (TNF-a), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and interleukin-18 (IL-18), and neutrophil infiltration. Additionally, irigenin inhibited pulmonary apoptosis in LPS-treated ALI mice. Moreover, LPS-induced phosphorylation of p38, JNK, and ERK was significantly abated due to the treatment of irigenin. In summary, irigenin ameliorates LPS-induced ALI by suppressing pulmonary inflammation and apoptosis via inactivation of the MAPK signaling pathway. These findings indicated the therapeutic potential of irigenin in ALI.

Influence of omega- 3 fatty acids, soya isoflavones and their combination for abrogating carbon tetrachloride hazards in male rats.

Studies have shown that carbon tetrachloride (CCl4) induces hepatic and renal damage arising from oxidative stress. The present study was undertaken to examine the effect of omega-3 fatty acids and/or soya isoflavones on CCl4 induced toxicity in male albino rat liver and kidney. For this purpose, 42 rats were divided as follows: group 1, rats serves as the control without any treatment; group 2, rats were administered a single dose of CCl4 intraperitoneally (1 mg/kg b. wt.); group 3, rats were supplemented daily with omega-300 orally (400 mg/kg b. wt.); group 4, rats were supplemented daily with pro-S orally (50 mg/kg b. wt.); group 5, rats were supplemented daily with omega-300 orally for four weeks, then after 24 hours treated with a single dose of CCl4 at the same tested doses. group 6, rats were supplemented daily with pro- S orally for four weeks, then after 24 hours treated with a single dose of CCl4 at the same tested doses; group 7, rats were supplemented daily with an oral combination of omega-300 and pro-S orally for four weeks, then after 24 hours treated with a single dose of CCl4 at the same tested doses. Results showed that CCl4 administration induces hepatic damage indicated by a significant increase in the activities of alkaline phosphatase (ALP), aspartate aminotransferase (AST) and Aalanine aminotransferase (ALT) enzymes and glucose level, with a significant increase in malondialdehyde (MDA) and nitric oxide (NO) levels and a significant decrease of reduced glutathione (GSH) level in liver tissue. Also, CCl4 toxicity induce renal damage manifested in a significant increase in serum urea, creatinine, uric acid, and oxidative stress of kidney tissue reflected by increase of MDA, NO and the decrease of GSH levels. The pre-treatment with omega-3 fatty acids and/or soya isoflavones revealed ameliorative effect against deleterious effects of CCl4 toxicity on hepatic and renal tissues and all tested parameters. Results of the current study revealed also that the pre-treatment with omega-3 fatty acids and/or soya isoflavones to rats improved liver and kidney function and produced high antioxidant activity.

Identification of yeast α-glucosidase inhibitors from Pueraria lobata by ligand fishing based on magnetic mesoporous silicon combined with knock-out/knock-in technology.

In this study, a ligand fishing technique based on magnetic mesoporous silicon was established and used to screen α-glucosidase inhibitors from Pueraria lobata. To clarify quantity-activity relationships in a holistic view, the knock-out/knock-in technology was used to analyse the interactions of several active constituents in P. lobata. Magnetic mesoporous silicon with a large specific surface area and better biocompatibility was synthesised. Subsequently, α-glucosidase was immobilised on -NH2-modified magnetic mesoporous silicon, and the compounds in the crude extract of P. lobata were screened across enzyme binding. The structures of the ligands were elucidated using UPLC-Q-TOF-MS/MS, and their activities were verified by knock-out/knock-in experiments and molecular docking. Daidzein and puerarin showed α-glucosidase inhibitory activities with an IC50 of 0.088 ± 0.003 mg mL-1 and 0.414 ± 0.005 mg mL-1, respectively. Among them, puerarin, which accounted for more than 40% of the total content, showed synergistic effects with other components and was the main contributor to the α-glucosidase inhibitory activity of P. lobata.

Changes in the content of Puerarin-PLGA nanoparticles in mice under the influence of alcohol and analysis of their antialcoholism.

To observe the metabolic changes and antialcoholic effect of Puerarin-PLGA nanoparticles (PUE-NP) in mice. PUE-NP was prepared and characterized by particle size distribution and morphology. The mouse models with acute alcoholism were established to observe their behavioral changes after alcohol poisoning. The expressions of biologically active enzymes such as CRE, BUN, AST, ALT in serum and SOD and TLR4 in liver of mice in each group were detected, and the pathological changes in liver and kidney tissues were observed by HE staining. The PUE-NP metabolism in mice was determined by in vitro release assay and HPLC. PUE-NP nanoparticles had good morphology and structure, and the mouse models with alcohol poisoning were established successfully. Compared with alcohol group, puerarin and PUE-NP increased the disappearance latency time of righting reflex, and the recovery time of righting reflex was significantly shortened. Water maze results showed that Puerarin and PUE-NP had inhibitory effect on impaired memory. HPLC results showed that PUE-NP reached its peak in mice after 1 h, and the content percentage was twice that of puerarin preparation alone, and the distribution time of puerarin concentration in vivo was prolonged, indicating that PLGA nanoparticles had a loading and slow-release effect on puerarin and increased the bioavailability of puerarin in mice. In addition, compared with the alcohol group, Puerarin and PUE-NP improved serum ALT, AST, CRE, and BUN levels in mice, enhanced SOD activity in liver, and inhibited TLR4 expression. The effect was better in the PUE-NP group than in the Puerarin group. PUE-NP delayed the release and metabolism of Puerarin and had better effect in the treatment of the alcoholic liver and kidney injury.

Review on the Diverse Biological Effects of Glabridin.

Glabridin is a prenylated isoflavan from the roots of Glycyrrhiza glabra Linne and has posed great impact on the areas of drug development and medicine, due to various biological properties such as anti-inflammation, anti-oxidation, anti-tumor, anti-microorganism, bone protection, cardiovascular protection, neuroprotection, hepatoprotection, anti-obesity, and anti-diabetes. Many signaling pathways, including NF-κB, MAPK, Wnt/ß-catenin, ERα/SRC-1, PI3K/AKT, and AMPK, have been implicated in the regulatory activities of glabridin. Interestingly, glabridin has been considered as an inhibitor of tyrosinase, P-glycoprotein (P-gp), and CYP2E1 and an activator of peroxisome proliferator-activated receptor γ (PPARγ), although their molecular regulating mechanisms still need further investigation. However, poor water solubility and low bioavailability have greatly limited the clinical applications of glabridin. Hopefully, several effective strategies, such as nanoemulsions, microneedles, and smartPearls formulation, have been developed for improvement.

Crystal structure of tubulin-barbigerone complex enables rational design of potent anticancer agents with isoflavone skeleton.

BACKGROUND: Isoflavones possess many biological activities, including anti-inflammatory and anticancer effects. Microtubules (composed of αß-tubulin heterodimers) are described as one possible cellular target of some of these isoflavones. However, the binding of tubulin to isoflavones has not been extensively studied, and until now, no crystal structure of the tubulin-isoflavone complex has been solved, and details of the isoflavone-tubulin interaction remain elusive. PURPOSE: Barbigerone is an isoflavone mainly found in the genus Milletti, such as the edible leguminous plant Millettia ferruginea, with anticancer activity. This study aims to confirm the cellular target of barbigerone and to study its anticancer mechanism. METHOD: Surface plasmon resonance assays and X-ray crystallography were used to study the interaction of barbigerone with tubulin protein. Immunofluorescence, in-cell and in vitro tubulin polymerization assays were employed to investigate the mechanism. MTT assays, cell clonal formation assays, wound healing assays, tube formation assays and H460 xenograft models were conducted to evaluate the in vitro and in vivo anticancer activities of barbigerone and one of its derivatives, 0412. RESULTS: Here, we found that barbigerone binds to tubulin to inhibit tubulin polymerization. Moreover, we solved the X-ray crystal structure of the tubulin-barbigerone complex at 2.33 Å resolution, which unambiguously determined the orientation and position of barbigerone in the colchicine-binding site. Illuminated by the X-ray data, we synthetized and obtained a more active isoflavone, 0412. Both barbigerone and 0412 inhibit cancer cell proliferation, tubulin polymerization, migration of HeLa cells and capillary-like tube formation of HUVECs, induce G2/M phase cell cycle arrest and apoptosis, and exhibit anticancer activity in an H460 xenograft model. CONCLUSION: In all, through biochemical and X-ray crystal structure results, we identified tubulin as the cellular target of one isoflavone, barbigerone, and proved that the tubulin-barbigerone complex plays a guiding role in obtaining a more active compound, 0412. These studies provide a crucial research basis for the development of isoflavones as anticancer candidate compounds.

Daidzein phosphorylates and activates 5-lipoxygenase via the MEK/ERK pathway: a mechanism for inducing the production of 5-lipoxygenase metabolite that inhibit influenza virus intracellular replication.

We previously reported that the soy isoflavone daidzein (Dz) suppresses the intracellular replication of influenza virus and that arachidonic acid-derived oxidation product via lipid oxidase 5-lipoxygenase (5-LOX) is involved in its antiviral effect. The activation of 5-LOX by Dz triggers anti-influenza activity; however, the mechanism of activation of 5-LOX remains unclear. Therefore, in this study, we aimed to clarify the activation mechanism using human monocyte-derived THP-1 cells differentiated using phorbol 12-myristate 13-acetate. THP-1 cells expressed 5-LOX endogenously and Dz did not induce 5-LOX expression. However, 8 h after treatment with Dz, the amount of 5-hydroxyeicosatetraenoic acid (5-HETE), an arachidonic acid oxidation product via 5-LOX, increased significantly suggesting that the enzyme is activated regardless of changes in 5-LOX protein levels. Intracellular Ca2+ content, ATP concentration, 5-LOX protein phosphorylation, and 5-LOX intracellular localization are known 5-LOX activation factors. The intracellular Ca2+ and ATP concentrations were not affected by Dz treatment. The enzymatic activity of 5-LOX is regulated by the phosphorylation of three serine residues and four tyrosine residues. Pretreatment with inhibitors of each kinase revealed that Dz-induced 5-HETE production was suppressed by the MEK/ERK inhibitor. 5-LOX in which the Ser663 residue was phosphorylated was found to be increased in the nuclear fraction of Dz-treated THP-1 cells. Furthermore, immunocytochemistry showed that 5-LOX translocates to the nuclear envelope following Dz treatment. These results indicate that Dz activates 5-LOX by phosphorylating Ser663 via the MEK/ERK pathway. Thus, these results demonstrate that Dz exerts anti-influenza virus activity via the MEK/ERK signal transduction pathway.

A Randomized Controlled Trial of Soy Isoflavone Intake on Mammographic Density among Malaysian Women.

Soy intake is associated with lower breast cancer risk in observational studies concerning Asian women, however, no randomized controlled trials (RCT) have been conducted among Asian women living in Asia. This three-armed RCT assessed the effects of one-year soy isoflavone (ISF) intervention on mammographic density (MD) change among healthy peri- and postmenopausal Malaysian women. This study was registered at ClinicalTrials.gov (NCT03686098). Participants were randomized into the 100 mg/day ISF Supplement, 50 mg/day ISF Diet, or control arm, and assessed for change in absolute and relative dense area from digital mammograms conducted at enrolment and after 12 months, compared over time across study arms using Kruskal-Wallis tests. Out of 118 women enrolled, 91 women completed the intervention, while 27 women (23%) were lost in follow up. The ISF supplement arm participants observed a larger decline in dense area (−1.3 cm2), compared to the ISF diet (−0.5 cm2) and control arm (−0.8 cm2), though it was not statistically significant (p = 0.48). Notably, among women enrolled within 5 years of menopause; dense area declined by 6 cm2 in the ISF supplement arm, compared to <1.0 cm2 in the control arm (p = 0.13). This RCT demonstrates a possible causal association between soy ISF intake and MD, a biomarker of breast cancer risk, among Asian women around the time of menopause, but these findings require confirmation in a larger trial.

Daidzein ameliorates doxorubicin-induced cardiac injury by inhibiting autophagy and apoptosis in rats.

Backgrounds: Doxorubicin (Dox) is a classical antitumor antibiotic widely restricted for use due to its cardiotoxicity. Daidzein (Daid) is a soy isoflavone that enhances antioxidant enzyme systems and inhibits apoptosis to prevent cardiovascular diseases. In this study, we intended to assess whether Daid protects against Dox-induced cardiotoxicity and explored its underlying mechanisms. Methods: Male Sprague-Dawley (SD) rats were divided into five groups: control (Ctrl), 40 mg per kg per day Daidzein (Daid), 3 mg per kg per week doxorubicin (Dox), 20 mg per kg per day Daidzein + 3 mg per kg per week doxorubicin (Daid20 + Dox) and 40 mg per kg per day Daidzein + 3 mg per kg per week doxorubicin (Daid40 + Dox) groups. Cardiac function assessments, immunohistochemistry (IHC) and immunofluorescence (IF) analyses were initially performed in each group of rats. Secondly, the cell proliferative capacity analysis, AO staining, and LC3 puncta analysis were employed to evaluate the cellular response to Dox in H9c2 cells. Ultimately, the protein expressions of cleaved caspase3, LC3 II, Bcl-2, Bax, Akt, p-Akt, and cyclin D1 were examined by western blotting. Results: Pretreatment with a low dose of Daid rather than a high dose significantly enhanced cardiac function and alleviated histopathological deterioration of cardiomyocytes induced by Dox. Daid downregulated the protein levels of Bax, LC3 II, cleaved caspase3 and p-Akt, while up-regulating Bcl-2 and cyclin D1. The Akt agonist SC79 could invalidate all the protective effects of Daid both in vivo and in vitro. Conclusions: Daid reduced autophagy and apoptosis by inhibiting the PI3K/Akt pathway, thereby protecting the hearts from Dox-induced cardiac damage.

Anti-inflammation of hydrogenated isoflavones in LPS-stimulated RAW264.7 cells via inhibition of NF-κB and MAPK signaling pathways.

Isoflavones are commonly found in diets, such as soybean and clover. Their anti-inflammatory effects are due to the inhibition of the transcriptional regulation of NF-κB. Hydrogenated isoflavones are metabolites of isoflavones with higher bioavailability, however, there have been few studies on their anti-inflammatory effects. In this work, by using the LPS-stimulated RAW264.7 cell model, we investigated the anti-inflammatory effect and the underlying mechanism of hydrogenated isoflavones. Hydrogenated isoflavones reduced the production of LPS-stimulated pro-inflammatory mediators and enzymes, including TNF-α, IL-6, NO, iNOS and COX-2. The level of ROS was also diminished in LPS-stimulated RAW264.7 cells. Further mechanistic studies showcase that hydrogenated isoflavones block NF-κB and MAPK pathways via attenuation of p65 nuclear translocation and JNK, ERK, and p38 phosphorylation, respectively. In addition, we found that hydrogenated isoflavones display anti-proliferation effect in human colon cancer cells with wild-type p53. Together, hydrogenated isoflavones could be used as an adjuvant for the treatment of inflammation and cancer.

Coumaronochromones, flavanones, and isoflavones from the twigs and leaves of Erythrina subumbrans inhibit PTP1B and nitric oxide production.

A chemical investigation of the twigs and leaves of Erythrina subumbrans led to the isolation and structural elucidation of three coumaronochromones, erythrinasubumbrin A and (±)-erythrinasubumbrin B, five prenylated flavanones, (±)-erythrinasubumbrin C and erythrinasubumbrins D-F, and two prenylated isoflavones, (±)-5,4'-dihydroxy-[4,5-cis-4-ethoxy-5-hydroxy-6,6-dimethyl-4,5-dihydropyrano (2,3:7,6)]-isoflavone, in addition to 18 known analogues. Two extra cinnamylphenols previously only known as commercial synthetic products were also isolated and elucidated from a natural source for the first time, and assigned the trivial names erythrinasubumbrins G and H. Their structures were characterized by detailed analysis of spectroscopic data, including HRESIMS and 2D NMR. The absolute configurations of the previously undescribed isolates and the known coumaronochromone lupinol C were determined by specific rotation and electronic circular dichroism (ECD) data. All the isolates were evaluated for their inhibitory activities on protein tyrosine phosphatase 1 B (PTP1B) and nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells as well as their cytotoxicity against the HCT116 cell line. The pair of enantiomers, (+)-5,4'-dihydroxy-[4,5-cis-4-ethoxy-5-hydroxy-6,6-dimethyl-4,5-dihydropyrano (2,3:7,6)]-isoflavone and (-)-5,4'-dihydroxy-[4,5-cis-4-ethoxy-5-hydroxy-6,6-dimethyl-4,5-dihydropyrano (2,3:7,6)]-isoflavone, and the known compounds lupinol C, 4'-O-methyl-8-prenylnaringenin, glepidotin B, shuterin, parvisoflavones A, luteone, lupiwighteone, 2,3-dehydrokievitone, 6,8-diprenylgenistein, angustone A, and 2'-O-demethylbidwillol B exhibited different levels of PTP1B inhibitory activities with IC50 values ranging from 3.21 to 19.17 µM, while erythrinasubumbrin A, (-)-erythrinasubumbrin B, (+)-5,4'-dihydroxy-[4,5-cis-4-ethoxy-5-hydroxy-6,6-dimethyl-4,5-dihydropyrano (2,3:7,6)]-isoflavone, (-)-5,4'-dihydroxy-[4,5-cis-4-ethoxy-5-hydroxy-6,6-dimethyl-4,5-dihydropyrano (2,3:7,6)]-isoflavone, and the known compounds lupinol C, 8-prenylnaringenin, macatrichocarpin A, alpinumisoflavone, and 2'-O-demethylbidwillol B substantially inhibited NO production in BV-2 microglial cells. In addition, 8-prenylnaringenin showed weak cytotoxicity with an IC50 value of 9.13 µM. This is the first report of PTP1B inhibitory activity for a coumaronochromone.

Microbial Dimerization and Chlorination of Isoflavones by a Takla Makan Desert-Derived Streptomyces sp. HDN154127.

Sixteen new biisoflavones, bisoflavolins A-N (1-16), were discovered from cultures of the Takla Makan desert-derived strain Streptomyces sp. HDN154127. The chemical structures, including axial chirality, were elucidated by NMR, MS, and ECD analyses. Antibacterial activity of dimerized compounds was tested against seven different bacteria. The dimerized compounds showed better activity (MIC from 0.8 to 50.0 µM) than the corresponding monomers (daidzein and genistein, MIC > 50.0 µM). The rare dimeric and chlorinated structures in 1-16 were proved to be biotransformation products obtained from soy isoflavones and sodium chloride, which constituted the culture medium. This is the first report of an actinomycete that promotes both dimerization and chlorination utilizing natural isoflavones as skeletons sources.

Chickpea and Lupin Sprouts, Stimulated by Different LED Lights, As Novel Examples of Isoflavones-Rich Functional Food, and Their Impact on Breast and Prostate Cells.

Among all legumes sprouts' active compounds, isoflavones seem to be the most important; nevertheless, their high content is not always associated with beneficial effects. These compounds may prevent or stimulate hormone-dependent cancers due to their estrogen-like activity. Different LED light quality can change the synthesis of active compounds and significantly influence the biological activity of the sprouts. This study aimed to evaluate the effects of LED light (red, blue, green, yellow), as well as total darkness, and natural light conditions (as reference), on isoflavones content, determined by HPLC-UV-VIS, during 10 days of harvesting of chickpea and lupin sprouts. Due to the ambiguous estrogenic potential of isoflavones, the impact of these sprouts on normal and cancer prostate and breast cells was evaluated. Yellow LED light resulted in the highest sum of isoflavones in chickpea sprouts (up to 1 g/100 g dw), while for green LED light, the isoflavones sum was the lowest. The exact opposite effect was noted for lupin sprouts, with the predominance of green over the yellow LED light. The examined sprouts were of high safety to non-neoplastic breast and prostate cells, with interesting cytotoxic effects on breast MCF7 and prostate DU145 cancer cells. No clear relationship was observed between the activity and isoflavones content.

Inhibition of α1-Adrenergic, Non-Adrenergic and Neurogenic Human Prostate Smooth Muscle Contraction and of Stromal Cell Growth by the Isoflavones Genistein and Daidzein.

Isoflavone-rich legumes, including soy, are used for food production, as dietary supplements and in traditional medicine. Soy consumption correlates negatively with benign prostatic hyperplasia (BPH) and voiding symptoms. However, isoflavone effects on the prostate are hardly known. Here, we examined the effects on human prostate smooth muscle contractions and stromal cell growth, which are driving factors of voiding symptoms in BPH. Smooth muscle contractions were induced in prostate tissues from radical prostatectomy. Growth-related functions were studied in cultured stromal cells (WPMY-1). Neurogenic, α1-adrenergic and non-adrenergic contractions were strongly inhibited with 50 µM and by around 50% with 10 µM genistein. Daidzein inhibited neurogenic contractions using 10 and 100 µM. Agonist-induced contractions were inhibited by 100 µM but not 10 µM daidzein. A combination of 6 µM genistein with 5 µM daidzein still inhibited neurogenic and agonist-induced contractions. Proliferation of WPMY-1 cells was inhibited by genistein (>50%) and daidzein (<50%). Genistein induced apoptosis and cell death (by seven-fold relative to controls), while daidzein induced cell death (6.4-fold) without apoptosis. Viability was reduced by genistein (maximum: 87%) and daidzein (62%). In conclusion, soy isoflavones exert sustained effects on prostate smooth muscle contractions and stromal cell growth, which may explain the inverse relationships between soy-rich nutrition, BPH and voiding symptoms.

Isoflavone-Enriched Soybean Leaves (Glycine Max) Alleviate Cognitive Impairment Induced by Ovariectomy and Modulate PI3K/Akt Signaling in the Hippocampus of C57BL6 Mice.

(1) Background: The estrogen decline during perimenopause can induce various disorders, including cognitive impairment. Phytoestrogens, such as isoflavones, lignans, and coumestans, have been tried as a popular alternative to avoid the side effects of conventional hormone replacement therapy, but their exact mechanisms and risk are not fully elucidated. In this study, we investigated the effects of isoflavone-enriched soybean leaves (IESLs) on the cognitive impairment induced by ovariectomy in female mice. (2) Methods: Ovariectomy was performed at 9 weeks of age to mimic menopausal women, and the behavior tests for cognition were conducted 15 weeks after the first administration. IESLs were administered for 18 weeks. (3) Results: The present study showed the effects of IESLs on the cognitive function in the OVX (ovariectomized) mice. Ovariectomy markedly increased the body weight and fat accumulation in the liver and perirenal fat, but IESL treatment significantly inhibited them. In the behavioral tests, ovariectomy impaired cognitive functions, but administration of IESLs restored it. In addition, in the OVX mice, administration of IESLs restored decreased estrogen receptor (ER) ß and PI3K/Akt expression in the hippocampus. (4) Conclusions: The positive effects of IESLs on cognitive functions may be closely related to the ER-mediated PI3/Akt signaling pathway in the hippocampus.

Soy Isoflavones and Bone Health: Focus on the RANKL/RANK/OPG Pathway.

Bone remodels via resorption and formation, two phenomena that continuously occur in bone turnover. The RANKL/RANK/OPG pathway is one of the several mechanisms that affect bone turnover. The RANKL/OPG ratio has a substantial role in bone resorption. An imbalance between formation and resorption is related to an increased RANKL/OPG balance. OPG, a member of this system, can bind to RANKL and suppress RANK-RANKL interaction, and subsequently, inhibit further osteoclastogenesis. The serum levels of RANKL and OPG in the bone microenvironment are vital for osteoclasts formation. The RANK/RANKL/OPG system plays a role in the pathogenesis of bone disorders. This system can be considered a new treatment target for bone disorders. Soy isoflavones affect the RANK/RANKL/OPG system through numerous mechanisms. Soy isoflavones decrease RANKL levels and increase OPG levels. Therefore, isoflavones improve bone metabolism and decrease bone resorption. Soy isoflavones decrease serum markers of bone resorption and improve bone metabolism. However, while the available data are promising, the results of several studies reported no change in RANKL and OPG levels with isoflavones supplementation. In this regard, current evidence is insufficient for conclusive approval of the efficacy of isoflavones on RANKL/RANK/OPG and further research, including animal and human studies, are needed to confirm the effect of soy isoflavones on the RANKL/RANK/OPG pathway. This study was a review of available evidence to determine the role of isoflavones in bone hemostasis and the RANK/RANKL/OPG pathway. The identification of the effects of isoflavones on the RANKL/RANK/OPG pathway directs future studies and leads to the development of effective treatment strategies for bone disorders.