Salvadora persica attenuates DMBA-induced mammary cancer through downregulation oxidative stress, estrogen receptor expression and proliferation and augmenting apoptosis.

Naturally occurring phytochemicals especially polyphenolic compounds have received increasing attention as chemopreventive agents. The chemopreventive potential of the ethanolic extract of Salvadora persica L. fruits SP, (the arak tree or miswak) on 7,12-dimethylbenz (a) anthracene (DMBA)-induced mammary carcinogenesis in female albino rats was investigated in this work. Ethanolic extract of SP fruits was supplemented to the experimental groups at a concentration of 500 mg/kg body weight for 22 weeks. Administration of SP extract suppressed DMBA-induced mammary carcinogenesis as revealed by incidence of tumors in histological investigation. There was a significant reduction in cell proliferation and an increase in apoptosis with downregulation of estrogen receptor expression in the mammary tissue of SP-treated animals. Additionally, SP extract prevented the oxidative damage induced in breast tissues of DMBA-treated rats. SP treatment also decreased the viability of MCF-7 breast cancer cells and induced early and late apoptosis and induced S cell cycle arrest. The chemo-preventive properties and anticancer effects of SP could be attributed to its anti-oxidative and a high percentage of phenolic compounds and esters which were detected here in the SP fruit extract.

Atractylenolide II induces cell cycle arrest and apoptosis in breast cancer cells through ER pathway.

In this research, atractylenolide II (ATR II) on apoptosis, cell cycle cells via ER pathway in breast cancer (MDA-MB-231 and MCF-7) cells are assessed. The effect of ATR II on cell proliferation was detected by MTT assay. Additional flow cytometry, luciferase, the western blot were performed to detect the signaling pathway cytotoxicity of ATR II. We have also carried out autodock measurements to validate our results. Our findings showed ATR II could inhibit breast cancer cell growth by apoptosis mainly through G2/M-phase cell cycle arrest. Besides, the cytotoxicity of ATTR II on breast cancer was also correlated by the regulation of endrogen receptors and promising an anti-inflammatory activity via inhibiting NF-KB signaling pathways. Taking together, ATR II could be a potential anti-cancer drug for breast cancer.

The effect of hormonal levels and oxidative stress on bisphenol A and soy isoflavone reproductive toxicity in murine offspring.

Previous studies have suggested that human exposure to bisphenol A (BPA) and soy isoflavones (SIFs) can occur during pregnancy. The combination of these chemicals is hypothesized to have a toxic impact on the fetus. While BPA is an industrial chemical used widely in the manufacture of polycarbonate plastics and epoxy resins, SIFs are naturally occurring estrogen­like phytoestrogens. To determine the impact of the combination of BPA and SIFs on fetal development, the body weight, organ weight, anogenital distance and histopathological changes in the testes of F1 offspring were assessed in mice. Hormonal effects were determined by measuring serum levels of estrogen receptor (ESR), follicle­stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T). Additionally, mitochondrial DNA copy numbers, and the serum levels of malondialdehyde and superoxide dismutase, were determined to evaluate alterations in oxidative stress and potential toxicity. Exposure to BPA increased the body weight of the pups and reduced the ratio of anogenital distance to body weight, as well as testes weight. Moreover, BPA exposure also induced testicular lesions. The seminiferous tubules of testis were denatured in varying degrees and the lumen wall structure was disordered. The levels of ESR in all offspring and the T levels in male offspring significantly increased, compared with controls. Co­exposure to BPA and SIFs exacerbated these changes in body weight, testicular lesions and hormonal levels, relative to BPA exposure alone. Additionally, oxidative damage was only induced by high­dose BPA. Collectively, these findings suggested that BPA and SIFs could have synergistic effect on the reproductive system, which could be mediated by the regulation of ESR expression and testosterone release.

Effects of doxorubicin associated with amniotic membrane stem cells in the treatment of canine inflammatory breast carcinoma (IPC-366) cells.

BACKGROUND: Tumours in mammary glands represent the most common neoplasia in bitches, as in humans. This high incidence results in part from the stimulation of sex hormones on these glands. Among mammary tumours, inflammatory carcinoma is the most aggressive, presenting a poor prognosis to surgical treatment and chemotherapy. One of the most widely used chemotherapy drugs for breast cancer treatment is doxorubicin (DOXO). Alternative therapies have been introduced in order to assist in these treatments; studies on treatments using stem cells have emerged, since they have anti-inflammatory and immunomodulatory properties. The aim of this study was to evaluate the effects of DOXO and canine amniotic membrane stem cells (AMCs) on the triple-negative canine inflammatory mammary carcinoma cell line IPC-366. METHODS: Four experimental groups were analysed: a control group without treatment; Group I with DOXO, Group II with AMC and Group III with an association of DOXO and AMCs. We performed the MTT assay with DOXO in order to select the best concentration for the experiments. The growth curve was performed with all groups (I-III) in order to verify the potential of treatments to reduce the growth of IPC-366. For the cell cycle, all groups (I-III) were tested using propidium iodide. While in the flow cytometry, antibodies to progesterone receptor (PR), estrogen receptor (ER), PCNA, VEGF, IL-10 and TGF-ß1 were used. For steroidogenic pathway hormones, an ELISA assay was performed. RESULTS: The results showed that cells treated with 10 µg/mL DOXO showed a 71.64% reduction in cellular growth after 72 h of treatment. Reductions in the expression of VEGF and PCNA-3 were observed by flow cytometry in all treatments when compared to the control. The intracellular levels of ERs were also significantly increased in Group III (4.67% vs. 27.1%). Regarding to the levels of steroid hormones, significant increases in the levels of estradiol (E2) and estrone sulphate (S04E1) were observed in Groups I and III. On the other hand, Group II did not show differences in steroid hormone levels in relation to the control. We conclude that the association of DOXO with AMCs (Group III) promoted a reduction in cell growth and in the expression of proteins related to proliferation and angiogenesis in IPC-366 triple-negative cells. CONCLUSIONS: This treatment promoted ER positive expression, suggesting that the accumulated oestrogen conducted these cells to a synergistic state, rendering these tumour cells responsive to ERs and susceptible to new hormonal cancer therapies.

Screening and Reverse-Engineering of Estrogen Receptor Ligands as Potent Pan-Filovirus Inhibitors.

Filoviridae, including Ebola (EBOV) and Marburg (MARV) viruses, are emerging pathogens that pose a serious threat to public health. No agents have been approved to treat filovirus infections, representing a major unmet medical need. The selective estrogen receptor modulator (SERM) toremifene was previously identified from a screen of FDA-approved drugs as a potent EBOV viral entry inhibitor, via binding to EBOV glycoprotein (GP). A focused screen of ER ligands identified ridaifen-B as a potent dual inhibitor of EBOV and MARV. Optimization and reverse-engineering to remove ER activity led to a novel compound 30 (XL-147) showing potent inhibition against infectious EBOV Zaire (0.09 µM) and MARV (0.64 µM). Mutagenesis studies confirmed that inhibition of EBOV viral entry is mediated by the direct interaction with GP. Importantly, compound 30 displayed a broad-spectrum antifilovirus activity against Bundibugyo, Tai Forest, Reston, and Menglà viruses and is the first submicromolar antiviral agent reported for some of these strains, therefore warranting further development as a pan-filovirus inhibitor.

Arachidonic acid alleviates the detrimental effects of acetylsalicylic acid on human granulosa cells performance in vitro.

Here, we investigated the biological effects of arachidonic acid (AA) in human cumulus granulosa cells (CGCs) after exposure to ASA. Cells were isolated from the follicular fluid and incubated with 0.5 mM acetylsalicylic acid (ASA) and 50 µM AA. Cell viability was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. E2 and P4 levels were measured by chemiluminescence assay. Expression of genes including CYP19A1, FACN, and SCD1 was measured by real-time polymerase chain reaction assay. Oxidative status was analyzed by monitoring glutathione peroxidase activity. The fatty acid profile was analyzed by the gas chromatography technique. Enzyme-linked immunosorbent assay was used to measure prostaglandin E2 (PGE2 ) in CGCs after exposure to ASA and AA. Protein levels of the estrogen receptor were studied by immunofluorescence staining. Ultrastructural changes were evaluated by transmission electron microscopy imaging. ASA treatment reduced E2 production, Cyp19a1 expression, glutathione peroxidase (GPx) activity, and estradiol receptor expression in CGCs. The addition of AA prevented the ASA-induced E2 reduction (p < .05) and expression of Cyp19a1. Moreover, AA increased the antioxidant capacity of CGCs exposed to ASA by promoting GPx activity (p < .05). AA increased monounsaturated fatty acid/saturated fatty acid ratio compared with the ASA group (p < .05). AA supplementation triggered the synthesis and secretion of PGE2 in ASA-treated CGCS (p < .05). Cytoplasmic vacuolation observed in the ASA group and treatment with AA intensified vacuolation rate. The expression of the estrogen receptor was increased after AA supplementation. Data demonstrated that AA decreased the detrimental effects of ASA on human CGCs after 72 hr.

Neonatal treatment with clomipramine modifies the expression of estrogen receptors in brain areas of male adult rats.

The participation of estrogens in depression has been well recognized. To exert its effects, estradiol binds mainly to estrogen receptors ESR1 and ESR2 (α and ß, respectively), expressed in brain regions including the hippocampus, limbic regions and hypothalamic nuclei. In rodents, modified estrogen receptors expression in brain areas have been implicated in different signs similar to those observed in depressive patients. Neonatal clomipramine (CMI) treatment is a pharmacological manipulation that generates behavioral and neurochemical changes that persist throughout adulthood and resemble human depression. The aim of this study was to analyze whether CMI neonatal treatment modifies the expression of nuclear ESR1 and ESR2 in the hippocampus, amygdala basolateral (BLA), amygdala medial (MeA), hypothalamic medial preoptic area (mPOA) and raphe nucleus in male rats. Our results indicate that CMI treatment significantly induced an mRNA increase of ESR1 in the hypothalamus, additionally produce a reduction in the mRNA ESR2 expression in raphe accompanied of an increase in hypothalamus and amygdala. CMI treated rats show more immunorreactive cells to ESR1 (ESR1-ir) in mPOA, BLA, MeA, together with a reduction of these cells in the hippocampal CA1 region. Moreover, an increase in the number of immunorreactive cells to ESR2 (ESR2-ir), in BLA and MeA, was observed in CMI treated rats. Additionally, the hippocampal CA2 region and raphe nucleus showed a decrease in these cells. Also, neonatal CMI treatment induced a decrease in the number of cells of the pyramidal layer in CA1. Overall, the results suggest that neonatal CMI treatment in rats (during brain development) induces changes in estrogen receptors in different brain areas involved with the regulation of depressive-like behaviors.

Estrogenic Activity of Coffee Constituents.

Here, the constituents of coffee with estrogenic activity are summarized by a comprehensive literature search, and their mechanisms of action for their physiological effects are discussed at the molecular and cellular levels. The estrogenic activity of coffee constituents, such as acids, caramelized products, carbohydrates, lignin, minerals, nitrogenous compounds, oil (lipids), and others, such as volatile compounds, was first evaluated by activity assays, such as animal tests, cell assay, ligand-binding assay, protein assay, reporter-gene assay, transcription assay, and yeast two-hybrid assay. Second, the health benefits associated with the estrogenic coffee constituents, such as bone protection, cancer treatment/prevention, cardioprotection, neuroprotection, and the improvement of menopausal syndromes, were summarized, including their potential therapeutic/clinical applications. Inconsistent results regarding mixed estrogenic/anti-estrogenic/non-estrogenic or biphasic activity, and unbeneficial effects associated with the constituents, such as endocrine disruption, increase the complexity of the effects of estrogenic coffee constituents. However, as the increase of the knowledge about estrogenic cell signaling, such as the types of specific signaling pathways, selective modulations of cell signaling, signal crosstalk, and intercellular/intracellular networks, pathway-based assessment will become a more realistic means in the future to more reliably evaluate the beneficial applications of estrogenic coffee constituents.

Silibinin protects rat pancreatic ß-cell through up-regulation of estrogen receptors' signaling against amylin- or Aß1-42 -induced reactive oxygen species/reactive nitrogen species generation.

Amylin and amyloid-ß (Aß) were found to induce reactive oxygen species (ROS) and reactive nitrogen species (RNS) in rat pancreatic ß-cell line, INS-1 cells, leading to cell death. In this study, we report on reciprocal relationship between the expression of estrogen receptors (ERs) α and ß (ERα and ERß) and generation of ROS/RNS in amylin/Aß1-42 -treated INS-1 cells. That is, pharmacological activation of ERs in INS-1 cells significantly decreases ROS/RNS generation, but blockage of ERs increases ROS/RNS generation. Silibinin is a natural polyphenolic flavonoid isolated from milk thistle with phytoestrogen activities, also known as silybin. Treatment with silibinin down-regulated ROS/RNS production induced by treatment with amylin/Aß1-42 in the cells. Silencing ERs expression with siRNAs targeting ERs showed that the protective effect of silibinin was markedly weakened, indicating that silibinin protection is largely attributed to activation of ERs' signaling. The binding of silibinin to ERs implies that the protective effect of silibinin on amylin/Aß1-42 -treated INS-1 cells owes to down-regulation of ROS/RNS through the activation of ERs phosphorylation. Amylin and Aß1-42 cotreatment enhanced furthermore ROS/RNS generation and cytotoxicity through further down-regulation of ERs phosphorylation, and this was reversed by silibinin. Silibinin also protects INS-1 cells from amylin and Aß1-42 cotreatment. These results indicate that protective effect of silibinin is mediated by enhancement of ERs phosphorylation that depresses ROS/RNS generation in amylin/Aß1-42 -treated INS-1 cells.

Natural Estrogen Receptor Modulators and Their Heterologous Biosynthesis.

Estrogen receptors (ERs) are transcription factors highly involved in physiological development and metabolism in the human body. They also play important roles in the treatment of cancer and metabolic diseases. Chemicals that interact with ERs can be used to treat diseases and maintain health. Phytoestrogens are natural chemicals that have been documented to possess significant ER modulatory activities. However, since phytoestrogens usually exist at low quantities in nature, heterologous biosynthesis techniques have quickly developed in recent years in order meet the demands for needed therapeutic amounts. In this review, the performance of phytoestrogens as ER modulators is described along with recent advances in biosynthesis techniques.

Embryoid body test with morphological and molecular endpoints implicates potential developmental toxicity of trans-resveratrol.

Developmental toxicity of compounds, which women of reproductive age are exposed to, should be assessed to minimize the incidence of miscarriage and birth defects. The present study examined the potential developmental toxicity of resveratrol, a dietary supplement widely marketed with various health claims, using the P19C5 embryoid body (EB) morphogenesis assay, which evaluates adverse effects of chemical exposures on tissue growth and axial elongation. Resveratrol (trans isoform) impaired morphogenesis at 4 µM and higher, creating smaller and rounder EBs, whereas cis isoform, and glucuronated and sulfonated metabolites did not. Trans-resveratrol also altered expression levels of developmental regulator genes involved in embryonic patterning, such as Wnt3a, Tbx6, and Cyp26a1. To investigate the mechanisms of trans-resveratrol action, the roles of estrogen receptor, sirtuin 1 (SIRT1), and DNA replication in EB morphogenesis were examined. Neither activators of estrogen receptors (diethylstilbestrol [18 µM] and raloxifene [8 µM]) nor activator of SIRT1 (SRT1720 [2.4-3.2 µM]) caused morphological and molecular alterations that are comparable to trans-resveratrol (10 µM). By contrast, a reduction in the DNA replication rate with aphidicolin (0.4 µM) or hydroxyurea (40 µM) created smaller and rounder EBs and altered the expression levels of Wnt3a, Tbx6, and Cyp26a1 in a manner similar to trans-resveratrol. Consistently, trans-resveratrol significantly reduced the rate of EdU incorporation in P19C5 cells. These results suggest that a reduction in the DNA replication rate is one of the mechanisms by which trans-resveratrol impacts EB development. This study provides mechanistic insight for further investigations on the developmental toxicity of trans-resveratrol.

Isolation and identification of three new chromones from the leaves of Pimenta dioica with cytotoxic, oestrogenic and anti-oestrogenic effects.

CONTEXT: Pimenta dioica (L.) Merr. (Myrtaceae) is used in Costa Rican traditional medicine for women's health. Our previous work showed that P. dioica extracts were oestrogenic. OBJECTIVES: This work identifies phytochemicals from P. dioica that are responsible for the plant's oestrogen-like activities. MATERIALS AND METHODS: P. dioica leaves were collected in Costa Rica in 2005. Fractions resulting from chromatographic separation of a methanol extract were tested at 50 µg/mL in a competitive oestrogen receptor-binding assay. Active compounds were isolated by HPLC and identified by NMR and MS. Pure compounds were tested at 1 µM in the oestrogen-responsive SEAP reporter gene assay. The effects on cell viability, cytotoxicity and apoptosis were investigated in breast cancer (MCF-7 and SK-BR3) and gastric cancer (AGS and NCI-N87) cell lines using the ApoTox-Glo and Caspase-Glo assays and qPCR. RESULTS: Quercitrin and three new chromones, including a 2-phenoxychromone, 6,8-di-C-methylcapillarisin (1) were isolated and identified. Compound 1 caused a 6.2-fold increase in SEAP expression at 1 µM (p < 0.05). This activity was blocked by the ER antagonist ICI 182,780. Compound 2 caused a 6.0-fold increase in SEAP, inhibited the growth of MCF-7, AGS and NCI-N87 cells (IC50 54.27, 38.13 and 51.22 µg/mL, respectively), and induced apoptosis via caspase 8 and increased the Bax/Bcl-2 mRNA ratio in MCF-7 cells. Compound 3 was anti-oestrogenic in MCF-7 cells. DISCUSSION AND CONCLUSIONS: Compounds from P. dioica have oestrogenic, anti-oestrogenic and cytotoxic effects that may explain the ethnomedical use of this plant.

Breast cancer amelioration by Butea monosperma in-vitro and in-vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Butea monosperma belonging to family Fabaceae is used in the Indian traditional medicine (Ayurveda) for various ailments including abdominal tumors and possess anti-estrogenic activity. AIM OF THE STUDY: The present study is aimed at investigating the chemo-preventive potential of Butea monosperma in breast cancer and elucidating it's mechanism of action by assessing its effect on key processes like apoptosis, angiogenesis and metastasis. METHODS: Cytotoxic potential of methanol extract of Butea monosperma flower (MEBM) was tested in MCF-7 (estrogen receptor positive), MDA-MB-231 (triple negative) and MDA-MB-453 (HER2 positive) human breast cancer cells by MTT assay. Chemo-preventive potential was evaluated in-vivo in Methylnitrosourea (MNU) induced mammary cancer in nulliparous Sprague-Dawley rats. The mechanism for anticancer potential was screened by in-vitro studies involving Annexin V- FITC assay (apoptosis), Chick Chorioallantoic Membrane assay (angiogenesis) and Migration assay (metastasis). Statistical analysis was done by one way and two way ANOVA (for Growth Rate and feed consumption efficiency) followed by post hoc Bonferroni's test with P value < 0.05. RESULTS: It is observed that the exposure of MEBM, at various concentrations and time intervals to different cell lines, resulted in decreased cell proliferation. The IC50 value of MCF-7 cells was found significantly less than that of MDA-MB-231 and MDA-MB-453 cells, which indicated that the extract of said medicinal plant were more potent inhibitors of estrogen positive breast cancer cells than other types of breast cancer cells in vitro. Corroborative evidences were acquired in MNU actuated mammary carcinogenesis where MEBM constricted tumor parameters, decreased expression of estrogen and progesterone, nucleic acid content and increased latency period. MEBM also induced apoptosis, inhibited angiogenesis and metastasis in-vitro. CONCLUSION: Selective cytotoxic activity in MCF-7 estrogen positive breast cancer cells and inhibition of growth of mammary carcinoma in-vivo by methanol extract of Butea monosperma flowers (MEBM) suggests chemo-prevention through modulation of estrogen and progesterone receptor, apoptotic, anti-angiogenesis and anti-metastatic activity.

The effects of soy and tamoxifen on apoptosis in the hippocampus and dentate gyrus in a pentylenetetrazole-induced seizure model of ovariectomized rats.

The effects of tamoxifen and soy on apoptosis of the hippocampus and dentate gyrus of ovariectomized rats after repeated seizures were investigated. Female rats were divided into: (1) Control, (2) Sham, (3) Sham-Tamoxifen (Sham-T), (4) Ovariectomized (OVX), (5) OVX-Tamoxifen (OVX-T), (6)OVX-Soy(OVX-S) and (7) OVX-S-T. The animals in the OVX-S, OVX-T and OVX-S-T groups received soy extract (60 mg/kg; i.p.), tamoxifen (10 mg/kg) or both for 2 weeks before induction of seizures. The animals in these groups additionally received the mentioned treatments before each injection of pentylenetetrazole (PTZ; 40 mg/kg) for 6 days. The animals in the Sham and OVX groups received a vehicle of tamoxifen and soy. A significant decrease in the seizure score and TUNEL-positive neurons was seen in the OVX group compared to the Sham (P < 0.001). The animals in both the OVX-T and OVX-S groups had a significantly higher seizure score as well as number of TUNEL-positive neurons compared to the OVX group (P < 0.01-P < 0.001). Co-treatment of the OVX rats by the extract and tamoxifen decreased the seizure score and number of TUNEL-positive neurons compared to OVX-S (P < 0.001). Treatment of the OVX rats by either soy or tamoxifen increased the seizure score as well as the number of TUNEL-positive neurons in the hippocampal formation. Co-administration of tamoxifen and soy extract inhibited the effects of the soy extract and tamoxifen when they were administered alone. It might be suggested that both soy and tamoxifen have agonistic effects on estrogen receptors by changing the seizure severity.

Phytoestrogenic effect of Inula racemosa Hook f - A cardioprotective root drug in traditional medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Roots of Inula racemosa are used as a cardio protective in Ayurveda in India, being prescribed as a medicine for precordial chest pain, cough and dyspnoea, both singly and as a poly herbal. AIM: Evaluation of Phytoestrogenic activity of the root extracts of Inula racemosa and compounds isolated therefrom in vivo, in silico and in vitro. MATERIALS AND METHODS: Alcohol (IrA) and hexane (IrH) extracts characterized by HPTLC/GC-MS analysis respectively and processed for compound isolation were evaluated for estrogenic activity (100 & 250mg/kg bw) by the Immature rat uterotrophic assay using ethinylestradiol (EE -30µg/kg bw) as standard drug. Alantolactone (ALT), Isoalantolactone (IALT) and Stigmasterolglucoside (SG) isolated from the extracts were characterized and screened in silico for ERα, ERß binding affinity, assessed in vitro for growth modulatory effects on MCF-7 cells by MTT assay and cell cycle distribution analysis using Flow cytometry. RT-PCR analysis evaluated the mRNA expression of pS2 in these cells post exposure to ALT, IALT and SG. RESULTS: In the IrA treated groups there has been a statistically significant increase (P < 0.05) in absolute and normalised uterine weight, uterine diameter, endometrial thickness, luminal epithelial cell height,diameter of ovary and in the number of primary and secondary ovarian follicles relative to untreated controls. Presence of ciliated epithelial cells in the oviduct, elevated number of early growing follicles characterized by an increased oocyte diameter, and signs of vascularization in the cortex of ovarian sections in this group relative to EE treated group are indicative of pervasive activation of follicular growth and initiation. Virtual docking demonstrated ERα affinity for IALT, ERß affinity for ALT, while SG showed a high binding affinity to both with a relatively greater ERß binding affinity. Dose dependent decrease in cell viability mediated by IALT and SG in the MTT assay is corroborated by a statistically significant increase (p < 0.05) in sub G0-G1 cells by SG at 200 and 400µM in cell cycle analysis and there has been an induction of pS2 by IALT and SG in the ER regulated MCF-7 cells. CONCLUSIONS: Demonstration of classical morphological changes induced by estrogen stimulation mediated by IrA in vivo at both the tested doses, isolation of the antioxidant SG from IrA and its dose dependent growth inhibitory effect on estrogen sensitive MCF-7 cells through apoptotic induction and an up regulation of pS2 are suggestive of an anti-estrogenic effect through estrogen receptor binding affinity, typical of phytoestrogens that bind to ER but do not elicit a full estrogenic response. The observed estrogenic effect of IrA suggests a multi mechanistic molecular action involving antioxidant as well as redox signalling pathways acting in consonance with their anti-estrogenic effects owing to the weak estrogen like competitive receptor binding of SG.

Glutamatergic Transmission to Hypothalamic Kisspeptin Neurons Is Differentially Regulated by Estradiol through Estrogen Receptor α in Adult Female Mice.

Estradiol feedback regulates gonadotropin-releasing hormone (GnRH) neurons and subsequent luteinizing hormone (LH) release. Estradiol acts via estrogen receptor α (ERα)-expressing afferents of GnRH neurons, including kisspeptin neurons in the anteroventral periventricular (AVPV) and arcuate nuclei, providing homeostatic feedback on episodic GnRH/LH release as well as positive feedback to control ovulation. Ionotropic glutamate receptors are important for estradiol feedback, but it is not known where they fit in the circuitry. Estradiol-negative feedback decreased glutamatergic transmission to AVPV and increased it to arcuate kisspeptin neurons; positive feedback had the opposite effect. Deletion of ERα in kisspeptin cells decreased glutamate transmission to AVPV neurons and markedly increased it to arcuate kisspeptin neurons, which also exhibited increased spontaneous firing rate. KERKO mice had increased LH pulse frequency, indicating loss of negative feedback. These observations indicate that ERα in kisspeptin cells is required for appropriate differential regulation of these neurons and neuroendocrine output by estradiol.SIGNIFICANCE STATEMENT The brain regulates fertility through gonadotropin-releasing hormone (GnRH) neurons. Ovarian estradiol regulates the pattern of GnRH (negative feedback) and initiates a surge of release that triggers ovulation (positive feedback). GnRH neurons do not express the estrogen receptor needed for feedback (estrogen receptor α [ERα]); kisspeptin neurons in the arcuate and anteroventral periventricular nuclei are postulated to mediate negative and positive feedback, respectively. Here we extend the network through which feedback is mediated by demonstrating that glutamatergic transmission to these kisspeptin populations is differentially regulated during the reproductive cycle and by estradiol. Electrophysiological and in vivo hormone profile experiments on kisspeptin-specific ERα knock-out mice demonstrate that ERα in kisspeptin cells is required for appropriate differential regulation of these neurons and for neuroendocrine output.

Ginseng on Nuclear Hormone Receptors.

The first record of ginseng use dates back over two millennia, and ginseng is now popular in more than 35 countries. Ginsenosides are the pharmacological constituents responsible for the beneficial effects of ginseng. There is increasing evidence that ginseng and its bioactive ingredients are involved in the regulation of nuclear receptors, molecules that act in response to the specific binding of hormones, which link to a diverse array of signaling pathways, such as the ERK and PI3K/Akt pathways. Knowledge of the mechanism of how ginseng mediates these complexes is essential for the development of multi-target phytomedicine as possible therapy for different diseases. Here, we discuss the literature on the effects of ginseng and its constituents on estrogen, glucocorticoid, peroxisome proliferator-activated, and androgen nuclear hormone receptors, as well as how ginseng and its constituents exert their biological function in the treatment of cancer, obesity, and cardiovascular and neurological disorders. The accumulated results definitely show that the nuclear receptors are cellular targets of ginsenosides, but more rigorous data are required to establish and provide a scientific basis to confirm the suggested efficacy of ginseng or products with ginsenosides.

Oxyresveratrol Is a Phytoestrogen Exerting Anti-inflammatory Effects Through NF-κB and Estrogen Receptor Signaling.

Recent studies suggest an anti-inflammatory activity of oxyresveratrol, a stilbene extracted from Cortex mori root used in traditional Chinese medicine that also presents estrogen-like activity. We herein tested the hypothesis that oxyreservatrol exerts an anti-inflammatory effect through its estrogenic-like function. In MCF-7 cells, oxyresveratrol significantly induced proliferation, which was accompanied with estrogen receptor (ER)-mediated transcriptional activation, increased estrogen-targeted gene expression (e.g., pS2, PGR, and CTSD), and increased ERα/ß proteins. The estrogen-like effect of oxyresveratrol was reversed by the ER inhibitor ICI 182780. Strong ER-binding activities of oxyresveratrol were revealed by negative docking scores. The LPS-induced inflammatory response (e.g., upregulated IκB-α phosphorylation, NF-κB nuclear translocation, and cytokine messenger RNA expression) was significantly suppressed in an ER-dependent manner by oxyresveratrol in RAW264.7 cells. These results suggest that oxyresveratrol may function as an ER agonist and modulate NF-κB signaling.

Cereal Lignans, Natural Compounds of Interest for Human Health?.

Cereals are suggested to be the most important sources of lignan in the diets of western populations. Recent epidemiological studies show that European subpopulations in which the major source of lignans are cereals, display lower disease frequency regarding metabolic and cardiovascular diseases. The biological mechanisms of lignan are several. Beyond their antioxidant and anti-inflammatory actions at nutritional doses some lignans regulate the activity of specific nuclear receptors (NRs), such as the estrogen receptors (ERs), and also NRs that are central switches in glucose and fatty acid metabolism such as PPARα, PPARγ and LXRs, highlighting them as selective nuclear receptor modulators (SNRMs). These include enterodiol (END) and enterolactone (ENL), the metabolites produced by the gut microbiota from food lignans. The available knowledge suggests that given some additional research it should be possible to make 'function' claims for a regular intake of lignans-rich foods related to maintaining a healthy metabolism.

The Effects of Petroselinum Crispum on Estrogen Receptor-positive Benign and Malignant Mammary Cells (MCF12A/MCF7).

BACKGROUND: Phytoestrogens have controversial effects on hormone-dependent tumors. Herein we investigated the effects of parsley root extract (PCE) on DNA synthesis performance, metabolic activity and cytotoxicity in malignant and benign breast cells. MATERIALS AND METHODS: The PCE was prepared and analyzed by mass spectrometry. MCF7 and MCF12A cells were incubated with various concentrations of PCE and analyzed for DNA synthesis performance, metabolic activity and cytotoxicity by BrdU proliferation, MTT and LDH assays, respectively. RESULTS: PCE was found to contain a substantial ratio of lignans. At a concentration range of 0.01 µg/ml-100 µg/ml the LDH assay analysis showed no significant cytotoxicity of PCE in both cell lines. However, at 500 µg/ml PCE's cytotoxicity was well over 70% of total cell population in both cell lines. According to the BrdU proliferation assay analysis, PCE demonstrated significant DNA synthesis inhibition of up to 80% at concentrations of 10, 50, 100 and 500 µg/ml in both cell lines. Based on the MTT assay analysis, only at a concentration of 500 µg/ml, PCE demonstrated a statistically significant inhibition of cellular metabolic activity of 63% in MCF7 and 75% in MCF12A of their respective normal capacity. CONCLUSION: PCE showed antiproliferative effects in MCF7 and MCF12A cells. Further investigation is required to determine whether this effect can be solely attributed to its phytoestrogens.