Estrogen Agonist Activity Research Articles

Association between tamoxifen and incidence of osteoporosis in Korean patients with ductal carcinoma in situ.

The partial estrogen-agonist action of tamoxifen on bone receptors has beneficial effects on bone mineral density. However, in premenopausal women, the use of tamoxifen causes systemic estrogen depletion, which has detrimental effects on bone health. We aim to investigate the association between tamoxifen and osteoporosis in the real world using data from a longitudinal nationwide cohort of Korean patients. Data were collected from the National Health Insurance claims database in South Korea. Osteoporosis was defined by diagnostic codes accompanying prescription data for osteoporosis. The cumulative incidence was analyzed by Kaplan-Meier survival curves and the risk factors were analyzed using a multivariable Cox proportional hazard regression model. Between 2009 and 2015, of the 4,654 women with ductal carcinoma in situ (DCIS) without prior osteoporosis, 2,970 were prescribed tamoxifen and 1,684 were not. A total of 356 DCIS survivors were later diagnosed with osteoporosis during a median follow-up period of 84 months. In the overall population, tamoxifen was associated with a low risk of osteoporosis, before and after propensity matching adjusted for age, operation type, and comorbidities (before matching, hazard ratio [HR]=0.69, 95% confidence interval [CI]=0.559-0.851, p<0.001; after matching, HR=0.664, 95% CI=0.513-0.858, p=0.002). In the subgroup analysis, findings were consistent in postmenopausal women but were not evident in the younger age group. In a nationwide cohort study, a low risk of osteoporosis was associated with the use of tamoxifen. The protective effect of tamoxifen was more profound in older women and was not related to the incidence of osteoporosis in younger women.

Computational modeling approaches for developing a synergistic effect prediction model of estrogen agonistic activity

The concerns regarding the potential health threats caused by estrogenic endocrine-disrupting chemicals (EDCs) and their mixtures manufactured by the chemical industry are increasing worldwide. Conventional experimental tests for understanding the estrogenic activity of mixtures are expensive and time-consuming. Although non-testing methods using computational modeling approaches have been developed to reduce the number of traditional tests, they are unsuitable for predicting synergistic effects because current prediction models consider only a single chemical. Thus, the development of predictive models is essential for predicting the mixture toxicity, including chemical interactions. However, selecting suitable computational modeling approaches to develop a high-performance prediction model requires considerable time and effort. In this study, we provide a suitable computational approach to develop a predictive model for the synergistic effects of estrogenic activity. We collected datasets on mixture toxicity based on the synergistic effect of estrogen agonistic activity in binary mixtures. Using the model deviation ratio approach, we classified the labels of the binary mixtures as synergistic or non-synergistic effects. We assessed five molecular descriptors, four machine learning-based algorithms, and a deep learning-based algorithm to provide a suitable computational modeling approach. Compared with other modeling approaches, the prediction model using the deep learning-based algorithm and chemical-protein network descriptors exhibited the best performance in predicting the synergistic effects. In conclusion, we developed a new high-performance binary classification model using a deep neural network and chemical-protein network-based descriptors. The developed model will be helpful for the preliminary screening of the synergistic effects of binary mixtures during the development process of chemical products.

The phytoestrogenic potential of flavonoid glycosides from Selaginella moellendorffii via ERα-dependent signaling pathway.

Selaginella moellendorffii (SM) has been applied as an ethnic drug to treat conditions such as osteoporosis, idiopathic thrombocytopenic purpura, and chronic inflammation. It is known to be rich in flavonoids, including apigenin glycosides and unique elements of bioflavonoids. To investigate estrogen-like constituents of SM and the possible mechanism. We identified the main components in liquid chromatography and liquid chromatography-mass spectrometry. The estrogenic effects were examined using a recombinant yeast screening assay, an E-screen cell proliferation assay, and an in vivo uterotrophic assay. Flavonoid glycosides extract, some flavonoid glycosides, and apigenin showed estrogen agonistic activity in the yeast screening assay. They also induced cell proliferation in estrogen receptor-positive (ER+) cells but not in estrogen receptor-negative (ER-) cells. Consistently, the protein expression of ERα, phosphorylation protein kinase B (p-AKT), phosphatidylinositol 3 kinase (PI3K), phosphorylation mammalian target of rapamycin (p-mTOR), phosphorylation 38,000-Da protein (p-P38), and phosphorylation extracellular-regulated kinase 1/2 (p-ERK1/2) elevated following treatment with flavonoid glycoside extract (P<0.01 or P<0.05). These effects could be blocked by ER antagonist or ERα antagonist but not be blocked by ERβ antagonist. In vivo assay, flavonoid glycoside extract could significantly increase body weight, serum estradiol level, uterine wet weight, alter uterine morphology, and promote ERα protein expression (P<0.01 or P<0.05). ERα induction via mitogen-activated protein kinases (MAPK) and PI3K/Akt/mTOR pathways might be the possible mechanism underlying the phytoestrogen effect of SM, and the flavonoid glycosides might be the critical estrogenic constituents.

Estrogenic, androgenic, and glucocorticoid activities and major causative compounds in river waters from three Asian countries.

Estrogen, androgen, and glucocorticoid receptors (ER, AR, and GR) agonist activities in river water samples from Chennai and Bangalore (India), Jakarta (Indonesia), and Hanoi (Vietnam) were evaluated using a panel of chemical-activated luciferase gene expression (CALUX) assays and were detected mainly in the dissolved phase. The ER agonist activity levels were 0.011-55ng estradiol (E2)-equivalent/l, higher than the proposed effect-based trigger (EBT) value of 0.5ng/l in most of the samples. The AR agonist activity levels were < 2.1-110ng dihydrotestosterone (DHT)-equivalent/l, and all levels above the limit of quantification exceeded the EBT value of 3.4ng/l. GR agonist activities were detected in only Bangalore and Hanoi samples at dexamethasone (Dex)-equivalent levels of < 16-150ng/l and exceeded the EBT value of 100ng/l in only two Bangalore samples. Major compounds contributing to the ER, AR, and GR agonist activities were identified for water samples from Bangalore and Hanoi, which had substantially higher activities in all assays, by using a combination of fractionation, CALUX measurement, and non-target and target chemical analysis. The results for pooled samples showed that the major ER agonists were the endogenous estrogens E2 and estriol, and the major GR agonists were the synthetic glucocorticoids Dex and clobetasol propionate. The only AR agonist identified in major androgenic water extract fractions was DHT, but several unidentified compounds with the same molecular formulae as endogenous androgens were also found.

Using in vitro bioassays to guide the development of safer bio-based polymers for use in food packaging.

Petroleum-based polymers traditionally used for plastic packaging production have been shown to leach dangerous chemicals such as bisphenol-A (BPA). Bio-based polymers are potentially safer alternatives, and many can be sustainably sourced from waste streams in the food industry. This study assesses bio-based polymers undergoing food packaging development for migration of endocrine disrupting leachates at the level of estrogen, androgen and progestagen nuclear receptor transcriptional activity. Reporter gene assays were coupled with migration testing, performed using standardised test conditions for storage and temperature. Test samples include nine bio-based polymers and four inorganic waste additives mixed with a traditional petroleum-based polymer, polypropylene. Thermoplastic starch material, polybutylene succinate, polycaprolactone, polybutylene adipate terephthalate (PBAT), two polylactic acid (PLA)/PBAT blends, polyhydroxybutyrate (PHB) and eggshell/polypropylene (10:90) presented no significant reduction in metabolic activity or hormonal activity under any test condition. Polypropylene (PP) presented no hormonal activity. Metabolic activity was reduced in the estrogen responsive cell line after 10 days migration testing of eggshell/polypropylene (0.1:99.9) in MeOH at 40°C, and PP in MeOH and dH20. Estrogenic agonist activity was observed after 10 days in poultry litter ash/polypropylene (10:90) in MeOH at 20°C and 40°C, poultry feather based polymer in MeOH and dH2O at 40°C, and eggshell/polypropylene (40:60) and PLA in dH2O at 40°C. Activity was within a range of 0.26–0.50 ng 17β-estradiol equivalents per ml, equating to an estrogenic potency of 3–∼2800 times less than the estrogenic leachate BPA. Poultry litter ash/polypropylene (10:90) in MeOH for 10 days presented estrogenic activity at 20°C and 40°C within the above range and anti-androgenic activity at 40°C. Progestagenic activity was not observed for any of the compounds under any test condition. Interestingly, lower concentrations of eggshell or PP may eliminate eggshell estrogenicity and PP toxicity. Alternatively eggshell may bind and eliminate the toxic elements of PP. Similarly, PLA estrogenic activity was removed in both PLA/PBAT blends. This study demonstrates the benefits of bioassay guidance in the development of safer and sustainable packaging alternatives to petroleum-based plastics. Manipulating the types of additives and their formulations alongside toxicological testing may further improve safety aspects.

Identifying potential paraben transformation products and evaluating changes in toxicity as a result of transformation.

Parabens are a class of compounds often used as preservatives in personal care products, pharmaceuticals, and food. They have received attention recently due to findings that demonstrate estrogenic impacts and other adverse effects of parabens. Release into wastewater effluent is considered a major contributor to the spread of parabens into surface water. Current regulations in areas such as Japan, Europe, and Southeast Asia limit the concentrations of parabens that can be used in formulations but do not address concentrations discharged into waterbodies. Recent studies suggest that parent parabens are effectively eliminated by transformation during the wastewater treatment processes. Common tertiary treatments include ultrafiltration, chlorination, UV disinfection and ozonation. Ultrafiltration is used to remove solids before a disinfection step. Of the disinfection steps, ozonation is often the most effective at removing parabens. Not much is known about the toxicities of paraben transformation products. Of the transformation products, chlorinated parabens and PHBA are the most studied. Previous studies have shown that chlorinated parabens have greatly reduced estrogen agonistic activity when compared with the activity of parents. However, more recent studies have found that halogenated parabens actually have estrogen antagonistic activity. Further research involving chlorinated parabens could include other toxic endpoints. No known studies have evaluated adverse effects of oxygenated parabens. Parabens can interact with chlorine residues in the environment and form chlorinated products, this will occur at a faster rate during chlorination. Ozonation will oxidize parabens and UV disinfection can both oxidize and halogenate parabens. All studies determining potential transformation products have been done in laboratory settings or specific conditions. Further research is needed to determine if these transformations occur in situ.Practitioner Points Common chemical processes utilized by wastewater treatment facilities are effective at transforming parabens.Paraben transformation products are released in greater concentration in effluent than parent paraben compounds.Halogenated transformation products have been identified as estrogen receptor antagonists.

New insights into potential estrogen agonistic activity of triazole fungicides and coupled metabolic disturbance

Triazole fungicides are highly effective pesticides widely used in plant protection, which has caused potential hazards to human health and ecological safety. To fully understand their potential hepatotoxicity, we first analyzed the transcriptome profiles in HepG2 cells treated with five triazole fungicides (hexiconazole (HEX), tebuconazole (TEB), propiconazole (PRO), cyproconazole (CYP), and difenoconazole (DIF)), and found that these pesticides remarkably affected estrogen signaling pathways, especially estrogen synthesis. Furthermore, we found that TEB, CYP, PRO and DIF had agonistic activity towards estrogen receptor alpha (ERα) and elucidated the binding mode of triazole ligands with ERα using the reporter gene assay and molecular docking. Four triazole fungicides regulated eight major genes involved in estrogen synthesis (StAR, CYP11A1, 3βHSD2, CYP17, CYP19, CYP3A4, CYP1A2 and SCP2) and stimulated the secretion of 17β-estradiol (E2). Finally, we assessed possible metabolic outcomes caused by abnormal estrogen synthesis, and found that triazole fungicides affected the metabolism of various macromolecules (such as lipid, amino acid, and carbohydrate) and signal transduction. These findings will provide new insights into endocrine-disrupting effects of triazole fungicides and highlight their potential ecological and health risks.

Selective Estrogen Receptor Modulators in Gynecology Practice.

Selective estrogen receptor (ER) modulators have variable tissue specific estrogen agonist and antagonist activities. Tamoxifen is approved for treatment and prevention of breast cancer; acts as an endometrial estrogen agonist. Raloxifene is approved for prevention and treatment of osteoporosis and prevention of breast cancer. The selective ER modulators bazedoxifene paired with conjugated estrogens relieves vasomotor symptoms and prevents bone loss with neutral effects on breast and amenorrhea similar to placebo. Ospemifene is approved to treat dyspareunia. Lasofoxifene is in development for resistant ER positive breast cancer. Estetrol (E4), synthesized by human fetal liver, has dual weak-estrogenic/antiestrogenic features, now approved as a contraceptive.

Estrogen Activity of OTC Topical Medications Containing Parabens Depends on Paraben Type and Concentration

Methylparaben, ethylparaben, and propylparaben are widely used as preservatives in food, cosmetics, and pharmaceutical products. Parabens are also known to bind the estrogen receptor and induce weak estrogen activity in laboratory bioassays. Many OTC topical medications contain one or more parabens as preservative ingredients. In this study, we surveyed the estrogen activity of extracts from OTC topical medications and tested the hypothesis that a combined threshold concentration of particular parabens is required to induce estrogen activity in human breast cancer cell bioassays. Ethanol extracts (1 gm:1 ml) were prepared from OTC topical medications containing parabens (including: Olay Quench Lotion, CeraVe Daily Moisturizing Lotion and Cortizon-10 Lotion). The estrogen agonist and antagonist activity of each extract was determined using the T47dkbluc estrogen reporter gene and the MCF-7 E3 estrogen responsive proliferation assays. The extracts from Olay Quench Lotion and CeraVe Daily Moisturizing Lotion induced estrogen agonist activity in the MCF-7 proliferation assay. The extract from the Cortizon-10 Lotion did not induce significant estrogen activity. The product ingredients of each OTC topical medications tested listed ethyl and propyl parabens while the Olay Quench Lotion also contained the least estrogenic paraben methylparaben. We propose that the estrogenic potential of OTC topical medications can be estimated with LC-MS analysis determination of paraben content and concentration. This study illustrates that measurable estrogen activity from OTC topical medications requires the presence of estrogenic parabens (ethyl and propyl) at total concentrations that exceed a threshold. Thus, estrogen activity depends on the type and concentration of paraben present in the OTC topical products. While the capacity for these OTC topical medications to induce estrogen activity in individuals using the products is unclear, consumers may benefit from more information about the paraben type and concentration present.

Bisacodyl in Stimulant Laxatives Can Induce Estrogen Agonist/Antagonist Activity in Breast Cancer Cells in Culture

Exposure to xenobiotic estrogens has the potential to induce estrogen activity that may contribute to a range of undesired physiological effects including the stimulation of estrogen responsive tumors. We have previously determined that extracts of OTC medications containing the stimulant laxative bisacodyl induce estrogenic activity in tissue culture bioassays. In this study, we tested the hypothesis that bisacodyl is responsible for the estrogen activity of these extracts and then characterized these effects. Ethanol extracts and dilutions were prepared from OTC medications containing Bisacodyl (1 gm:1 ml). The estrogen agonist and antagonist activity of each extract, as well as bisacodyl and then metabolite DA-bisacodyl was determined using the T47dkbluc estrogen reporter gene and the MCF-7 E3 estrogen responsive proliferation assays. LC-MS analysis was used to determine bisacodyl and DA-bisacodyl concentration in extracts as well as to trace the metabolism of bisacodyl to DA-bisacodyl in the cell culture bioassays. Molecular modeling “docking” simulations of the interactions of bisacodyl and the metabolite DA-bisacodyl with the estrogen receptor (ER) ligand binding domain was performed using MOE from Chemical Computing Group. Bisacodyl and the metabolite DA-bisacodyl induced mixed agonist/antagonist activity in MCF-7 E3 estrogen responsive proliferation assay similar to 4OH-tamoxifen. At the same time, both compounds stimulated only minimal estrogen activity in the T47dkbluc estrogen reporter gene assay. LC-MS analysis determinations identified that almost all bisacodyl was converted to the dihydroxy metabolite DA-bisacodyl in cell culture bioassays. Molecular modeling “docking” simulations determined that while bisacodyl does not fit into the agonist (estradiol) or antagonist (4OH-tamoxifen) conformations of the estrogen receptor ligand binding site, the metabolite DA-bisacodyl may fit into the antagonist induced binding pocket of the ER in a reasonable way. This study characterizes the observed estrogen activity of extracts from OTC medications containing bisacodyl as resulting from the bisacodyl metabolite DA-bisacodyl interacting with the estrogen receptor. Thus, bisacodyl is an OTC medication active ingredient that has potential to induce side effects and or toxicity involving estrogen signalling. The capacity for medications containing bisacodyl or other estrogenic substances to induce estrogen activity in patients is unclear. At the same time, consumers and practitioners should be aware of the potential estrogen activity of bisacodyl containing products.

Role of cholesterol metabolism in the anticancer pharmacology of selective estrogen receptor modulators.

Selective estrogen receptor modulators (SERMs) are a class of compounds that bind to estrogen receptors (ERs) and possess estrogen agonist or antagonist actions in different tissues. As such, they are widely used drugs. For instance, tamoxifen, the most prescribed SERM, is used to treat ERα-positive breast cancer. Aside from their therapeutic targets, SERMs have the capacity to broadly affect cellular cholesterol metabolism and handling, mainly through ER-independent mechanisms. Cholesterol metabolism reprogramming is crucial to meet the needs of cancer cells, and different key processes involved in cholesterol homeostasis have been associated with cancer progression. Therefore, the effects of SERMs on cholesterol homeostasis may be relevant to carcinogenesis, either by contributing to the anticancer efficacy of these compounds or, conversely, by promoting resistance to treatment. Understanding these aspects of SERMs actions could help to design more efficacious therapies. Herein we review the effects of SERMs on cellular cholesterol metabolism and handling and discuss their potential in anticancer pharmacology.

Toxicity characterization of surface sediments from a Mediterranean coastal lagoon

The occurrence of bioactive compounds and contaminant-associated effects was assessed by means of in vivo and in vitro assays using different extractable fractions of surface sediments from a contaminated coastal lagoon (Mar Menor, SE Spain). Sediment elutriates and clean seawater, previously exposed to whole sediment, were used for assessing the in vivo toxicity on embryo development of the sea urchin Paracentrotus lividus. Agonist and antagonist activities relating to estrogen and androgen receptors and agonist activities on aryl hydrocarbon receptor (expressed as ethoxyresorufin-O-deethylase (EROD) activities) were investigated in sediment extracts by using HER-Luc, AR-EcoScreenTM and fibroblast-like RTG-2 cell lines. Embryotoxicity effects were greater for sediment elutriates than those incubated in sediment-water interphase, implying that diffusion of bioactive chemicals can occur from sediments to sea water column, favoured by sediment disturbance events. In vitro results show the occurrence in extracts of compounds with estrogen antagonism, androgen antagonism and dioxin-like activities. Multidimensional scaling analysis classified the sampling sites into four sub-clusters according to their chemical-physical and biological similarities, relating in vitro bioactivity with the total organic carbon and known organic chemical load, with particular reference to total sum of PAHs, PCB 180, p,p-DDE and terbuthylazine. Overall, results pointed to the presence of unknown or unanalyzed biologically-active compounds in the sediments, mostly associated with the extracted polar fraction of the Mar Menor lagoon sediments. Our findings provide relevant information to be considered for the environmental management of contaminated coastal lagoons.

Investigation of In Vitro Endocrine Activities of Microcystis and Planktothrix Cyanobacterial Strains.

Cyanobacteria are cosmopolitan photosynthetic prokaryotes that can form dense accumulations in aquatic environments. They are able to produce many bioactive metabolites, some of which are potentially endocrine disrupting compounds, i.e., compounds that interfere with the hormonal systems of animals and humans. Endocrine disruptors represent potential risks to both environmental and human health, making them a global challenge. The aim of this study was to investigate the potential endocrine disrupting activities with emphasis on estrogenic effects of extracts from cultures of Microcystis or Planktothrix species. We also assessed the possible role of microcystins, some of the most studied cyanobacterial toxins, and thus included both microcystin-producing and non-producing strains. Extracts from 26 cyanobacterial cultures were initially screened in estrogen-, androgen-, and glucocorticoid-responsive reporter-gene assays (RGAs) in order to identify endocrine disruption at the level of nuclear receptor transcriptional activity. Extracts from selected strains were tested repeatedly in the estrogen-responsive RGAs, but the observed estrogen agonist and antagonist activity was minor and similar to that of the cyanobacteria growth medium control. We thus focused on another, non-receptor mediated mechanism of action, and studied the 17β-estradiol (natural estrogen hormone) biotransformation in human liver microsomes in the presence or absence of microcystin-LR (MC-LR), or an extract from the MC-LR producing M. aeruginosa PCC7806 strain. Our results show a modulating effect on the estradiol biotransformation. Thus, while 2-hydroxylation was significantly decreased following co-incubation of 17β-estradiol with MC-LR or M. aeruginosa PCC7806 extract, the relative concentration of estrone was increased.

Reactive Adsorption of Parabens on Synthesized Micro- and Mesoporous Silica from Coal Fly Ash: pH Effect on the Modification Process.

Parabens are widely used as preservatives in food, pharmaceutical, and cosmetic products. These compounds are known for their estrogen agonist activity. This research investigates the synthesis of micro- and mesoporous silica from coal fly ash at different pH values (13, 11, 9, and 7) as well as its use as an adsorbent for the removal of parabens. The materials were characterized, and X-ray fluorescence (XRF) analysis revealed that the fly ash acid treatment reduced the presence of aluminum, iron, and calcium oxides and also that silica synthesized at lower pH values (7 and 9) showed a higher SiO2 content. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses revealed microporous silica formation for silica synthesized at pH 13 and mesoporous silica at pH 7, 9, and 11. Adsorption tests were performed with materials, and FA-AT7 showed a higher adsorption capacity. The effect of factors (A) adsorbent mass, (B) initial paraben concentration, and (C) agitation rate on the adsorption process was studied for the FA-AT7 adsorbent using a factorial experimental design. Standardized Pareto charts revealed a negative effect of factor A, positive effect of factor B, and negative interaction effects of factors A–B for all studied parabens. Isotherms and multicomponent kinetic studies were performed. A linear type-III isotherm was obtained, and adsorption equilibrium was reached at approximately 10 min.

The mixture effects of bisphenol derivatives on estrogen receptor and androgen receptor

Bisphenol A (BPA) is a well-known for endocrine-disrupting chemical (EDC) and is one of the highest amounts of chemicals produced worldwide. Some countries restrict the use of BPA, which is widely used in the production of a variety products. Considering the toxicity and limitations on use of BPA, efforts are needed to find safer alternatives. Increasingly, bisphenol F (BPF) and bisphenol S (BPS) are alternatives of BPA, which is increasing their exposure levels in various environments. There are many ways to assess whether a chemical is an EDC. Here, we evaluated the endocrine-disrupting risks of the bisphenols by investigating their agonist and antagonist activities with the estrogen (ER), androgen (AR), and aryl hydrocarbon (AhR) receptors. Our results showed that BPA, BPS, and BPF (BPs) have estrogen agonist and androgen antagonist activities and decrease the ERα protein level. Interestingly, a mixture of the BPs had ER and anti-AR activity at lower concentrations than BPs alone. The activation of AhR was not a concentration-dependent effect of BPs, although it was increased significantly. In conclusion, BPs have estrogen agonist and androgen antagonist activities, and the effect of exposure to a BPs mixture differs from that of BPs alone.

Hormone therapy in menopausal women with fibroids: is it safe? (Literature review)

Hormone therapy is an effective treatment option for menopausal women, although prolonged use of hormone therapy is associated with a slightly increased risk of breast cancer, thromboembolism, and stroke. A literature search for studies evaluating the effects of hormone therapy in menopausal women with asymptomatic fibroids demonstrated variable effects of hormone therapy on the volume and size of the fibroids. Some studies have demonstrated an increase in size of pre-existing asymptomatic fibroids and formation of new fibroids with higher doses of progestogen in combination therapy. Selective estrogen receptor modulators having tissue-specific estrogen agonistic and antagonistic actions such as raloxifene have a favorable clinical profile and may be better alternatives in women with asymptomatic fibroids.

MON-033 Evaluating the Estrogen Activity of OTC Products Containing Parabens

Parabens such as methylparaben, ethylparaben, and propylparaben are widely used in food products, cosmetics, and pharmaceuticals as preservatives. Many products contain multiple parabens to enhance the preservative effect. Parabens have been shown to be weak estrogens with alkyl chain length directly related to activity. In this study, we test the hypothesis that extracts of OTC products containing paraben preservatives will induce estrogen activity in human breast cancer cells in culture. Five frequently used OTC products were selected where equivalent pairs of products (same active ingredient) were available: one with and one without paraben preservatives in the formulation. Ethanol extracts and dilutions were prepared of OTC preparations of: Calcium Carbonate, Bisacodyl, Ibuprofen, Diphenhydramine and Benzoyl Peroxide (1 gm:1 ml). The estrogen agonist and antagonist activity of each extract was determined using the T47dkbluc estrogen reporter gene and the MCF-7 E3 estrogen responsive proliferation assays. Estrogen agonist activity was observed after treatment with extracts from Bisacodyl and Benzoyl Peroxide preparations. Formulations of Bisacodyl with and without parabens each induced similar estrogen agonist activity. The Bisacodyl structure suggests some features of the estrogen pharmacophore and estrogen activity has been reported in the literature. Thus, observed Bisacodyl extract estrogen effects are likely due to the active ingredient. Estrogen activity of Benzoyl Peroxide extracts was only observed in the extract deriving from the formulation that contained parabens and thus activity is likely due to the paraben preservative. While Ibuprofen and Diphenhydramine product extracts with or without parabens did not induce significant estrogen activity in the bioassays, extracts from these products induced estrogen activity when combined with the antiestrogen fulvestrant. The cause for this apparent initiation of estrogen activity from antiestrogen treatment is unknown. This study highlights the potential for paraben preservatives in OTC products to induce observable estrogen activity. The importance of determining the estrogen activity of OTC products in general is also illustrated. While the capacity for OTC preparations containing parabens (or other estrogenic substances) to induce estrogen activity in individuals using the products is unclear, consumers may interested in the presence of estrogenic components in commonly used OTC products.

MON-034 Novel Estrogen Activity and Gene Regulation Induced by Personal Care Products in Breast Cancer Cells

The contribution of personal care product (PCP) use to hormone regulated cancer and cancer disparities is unknown. Considering that environmental estrogens and endocrine disrupting chemicals (EDCs) have the potential to contribute to cancer promotion and progression, evaluating chronic use PCPs and hair products for estrogen activity may be of use for risk assessment. In this study, we tested the hypothesis that the ethanol extracts of 11 PCPs (including hair products) would induce estrogen agonist or antagonist activity in breast cancer cells in culture. We have previously shown that three of these PCP extracts induce estrogen agonist activity in the MCF-7 E3 estrogen proliferation assay while six extracts induce estrogen antagonist effects in the T47dkbluc estrogen reporter gene assay. In the current study, the LanthaScreen TR-FRET ER Alpha Competitive Binding Assay was employed to confirm that all nine estrogenic PCP extracts bind to the ER with up to 85% of the activity of E2. Then, to compare endogenous gene regulation induced by the estrogenic PCP extracts with treatment with E2, the Qiagen RT2 Profiler PCR Array for Human Estrogen Receptor Signalling was utilized. MCF-7 cells were treated with solvent control, 1 nM E2 or one of the nine PCP extracts shown to have estrogen activity in bioassays. The three extracts with agonist activity in bioassays produced a gene activation pattern similar to E2 with fewer total genes induced. At the same time, these extracts had no effect on some genes E2 inhibited (compared to control). While the extracts with estrogen antagonist activity in the bioassays inhibited the transcription of most genes induced by E2, these extracts activated the transcription of a number of genes E2 either down regulated or did not regulate. The antagonist PCP extracts repressed transcription of as many as 20 genes such as GPER1, PGR, NR5A2, CAV1 relative to E2. At the same time, in contrast to E2, these extracts induced the transcription of genes such as CYP1A1, CKB, CTGF, WNT4, CTGF, S100A6, FST, NCOA1 CTGF, S100A6, FST, NCOA1, APBB1, PTCH1, MAFF, WNT5A, and/or NOV. We conclude that chronic exposure to these estrogenic or antiestrogenic PCPs has the potential to impact estrogen mediated signaling in exposed individuals that exposure may have an influence on the proliferation and survival of estrogen dependent cancer.

The Flavone Luteolin, an Endocrine Disruptor, Relaxed Male Guinea Pig Gallbladder Strips.

BackgroundLuteolin (3',4',5,7-tetrahydroxyflavone) is a flavone with a yellow crystalline appearance present in numerous plants such as broccoli, green chili, and carrot. Luteolin is considered to be an endocrine disruptor with potent estrogen agonist activity and potent progesterone antagonist activity. Luteolin has effects on smooth muscle. Luteolin relaxed guinea pig trachea smooth muscle as it inhibited both phosphodiesterase and reduced intracellular Ca2+. Luteolin also caused vasorelaxation in rat thoracic aorta smooth muscle by inhibiting intracellular Ca2+ release, inhibition of sarcolemmal Ca2+ channels, and activation of K+ channels. Luteolin or its glycosides from artichoke extracts may have an ameliorating effect on irritable bowel syndrome. The purpose of this study was to determine if luteolin had an effect on gallbladder motility.MethodsAn in vitro pharmacologic technique was utilized. Either cholecystokinin octapeptide (CCK) or KCl were used to induce tension in male guinea pig gallbladder strips maintained in Sawyer-Bartlestone chambers. Luteolin relaxed either the CCK- or KCl-induced tension in a concentration dependent manner. Various blockers were added to the chambers to determine which second messenger system(s) mediated the observed relaxation. Paired t-tests were used for statistical analysis. Differences between mean values of P < 0.05 were considered significant.ResultsTreatment of the gallbladder strips with luteolin prior to either KCl or CCK significantly (P < 0.001) decreased the amount of either KCl- or cholecystokinin-induced tension. The 2-aminoethoxydiphenylborane was used to ascertain if the release of intracellular Ca2+ mediated the luteolin-induced relaxation. It significantly (P < 0.001) decreased the amount of luteolin-induced relaxation. To ascertain if PKA mediated the luteolin-induced relaxation, PKA inhibitor 14-22 amide myristolated was used. It significantly (P < 0.01) reduced the amount of luteolin-induced relaxation. Neither KT5823, NG-methyl-L-arginine acetate salt, genistein, tetraethylammonium, nor fulvestrant had a significant effect. To ascertain if PKC mediated the luteolin-induced relaxation, the PKC inhibitors bisindolymaleimide IV and chelerythrine Cl- were used together. They had no significant effect.ConclusionsLuteolin relaxed cholecystokinin- or KCl-induced tension by blocking extracellular Ca2+ entry as well as intracellular Ca2+ release. In addition, the actions of PKA are also involved in mediating the luteolin effect.

Hormone therapy in menopausal women with fibroids: is it safe?

Menopause is an important transition in the life of women. It has been estimated that by the year 2030, worldwide 1.2 billion women will be menopausal. The most bothersome symptoms of menopause are believed to be due to declines in estrogen levels in postmenopausal women. Thus, hormone therapy is an effective treatment option for menopausal women, although prolonged use of hormone therapy is associated with a slightly increased risk of breast cancer, thromboembolism, and stroke. A literature search for studies evaluating the effects of hormone therapy in menopausal women with asymptomatic fibroids demonstrated variable effects of hormone therapy on the volume and size of the fibroids. Some studies have demonstrated an increase in size of pre-existing asymptomatic fibroids and formation of new fibroids with higher doses of progestogen in combination therapy. The finding of low resistance index in uterine arteries of women with asymptomatic fibroids is associated with an increased risk of fibroid growth, and thus making the measurement of pulsatility index of uterine arteries a possible screening tool before initiating hormone therapy in menopausal women with fibroids. Although the effect of hormone treatment is variable and statistically insignificant in many cases, the newer selective estrogen receptor modulators having tissue-specific estrogen agonistic and antagonistic actions such as raloxifene have a favorable clinical profile and may be better alternatives in women with asymptomatic fibroids.