• Title/Summary/Keyword: estradiol receptor

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Effect of Daisdzein on the Benzo(k)fluoranthene Regulated CYP1B1 Gene Expression (Daisdzein이 Benzo(k)fluoranthene에 의한 CYP1B1 유전자조절 작용에 미치는 영향)

  • Seo, Mi-Jeong;Kim, Yeo-Woon;Sheen, Yhun-Yhong
    • Environmental Mutagens and Carcinogens
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    • v.24 no.4
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    • pp.198-205
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    • 2004
  • Cytochrome P4501B1(CYP1B1) is known to be inducible by xenobiotic compounds such as policyclic aromatic hydrocarbon(PAH) and dioxins such as 2,3,7,8-tetrachloro-dibenzo-p-dioxin(TCDD). And these induction of CYP1B1 is also regulated by many categories of chemicals. In order to investigate the effects of several chemicals on CYP1B1 gene expression in Hepa-I and MCF-7 cells, 5' flanking DNA of human CYP1B1 was cloned into pGL3 basic vector containing luciferase gene, and then transfected into these cells. After treatment of chemicals, the luciferase activity was measured. CYP1B1 enzyme metabolize PAHs and estradiol. CYP1B1 metabolize estradiol to 4-hydrozyestradiol that is considered as carcinogenic metabolite. Recent industrialized industrialized society, human has been widely been exposed to widespread environmental contaminants such as PAHs(polycyclic aromatic hydrocarbon) that are originated from the imcomplete combustion of hydrocarbons. PAHs are known to be ligands of the AhR(aryl hydrocarbon receptor). Induction of cytochrome P4501B1(CYP1B1) in cell culture is widely used as a biomarker for PAHs. Therefore we have studied the effect of PAHs in the human breast cancer cells MCF-7 to evaluate bioactivity of PAHs. We have used the United State of America EPA selected 13 different PAHs, PAHs mixtures and extracts from environmental samples to evaluate the bioassay system. We examined effects of PAHs on the CYP1B1-luciferase reporter gene and CYP1B1 mRNA level. Benzo(k)fluoranthene and dibenzo(a, h)anthracene showed strong response to CYP1B1 promoter activity stimulation, and also CYP1B1 mRNAs increase in MCF-7 cells in a concentration-dependent manner. RT-PCR analysis indicated that PAHs significantly up-regulate the level of CYP1B1 mRNA. Some flavonoids such as genistein, daidzein, chrysin, naringenin and morin were also investigeted. These flavonoids decreased B(k)F infuced luciferase activity at low concentration. But, these flavonoids exhibited stimulatory effect at high concentration.

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Development of an Improved Menopausal Symptom-Alleviating Licorice (Glycyrrhiza uralensis) by Biotransformation Using Monascus albidulus

  • Kim, Kang Uk;Lee, Sung-Jin;Lee, Inhyung
    • Journal of Microbiology and Biotechnology
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    • v.30 no.2
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    • pp.178-186
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    • 2020
  • Licorice (Glycyrrhiza uralensis) contains several compounds that have been reported to alleviate menopausal symptoms via interacting with estrogen receptors (ERs). The compounds exist mainly in the form of glycosides, which exhibit low bioavailability and function. To bioconvert liquiritin and isoliquiritin, the major estrogenic compounds, to the corresponding deglycosylated liquiritigenin and isoliquiritigenin, respectively, licorice was fermented with Monascus, which has been demonstrated to deglycosylate other substances. The contents of liquiritigenin and isoliquiritigenin in Monascus-fermented licorice increased by 10.46-fold (from 38.03 μM to 379.75 μM) and 12.50-fold (from 5.53 μM to 69.14 μM), respectively, compared with their contents in non-fermented licorice. Monascus-fermented licorice exhibited 82.5% of the ERβ binding activity of that observed in the positive control (17 β-estradiol), whereas the non-fermented licorice exhibited 54.1% of the binding activity in an in vivo ER binding assay. The increase in the ERβ binding activity was associated with increases in liquiritigenin and isoliquiritigenin contents. Liquiritigenin acts as a selective ligand for ERβ, which alleviates menopausal symptoms with fewer side effects, such as heart disease and hypertension, compared with a ligand for ERα. In addition, Monascus-fermented licorice contained 731 mg/kg of monacolin K, one of the metabolites produced by Monascus that reduces serum cholesterol. Therefore, Monascus-fermented licorice is a promising material for the prevention and treatment of menopausal syndrome with fewer side effects.

Evaluation of Endocrine Disrupting Chemicals-Complex Mixture in Diesel Exhaust Respirable Particulate Matter

  • Ryu, Byung-Tak;Jang, Hyoung-Seok;Kim, Yun-Hee;Kim, Soung-Ho;Lee, Do-Han;Han, Kyu-Tae;Oh, Seung-Min;Chung, Kyu-Hyuck
    • Proceedings of the Korea Society of Environmental Toocicology Conference
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    • 2003.05a
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    • pp.195-195
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    • 2003
  • It is well known that diesel exhaust particulate matter contains mutagenic PAHs, such as benzo[${\alpha}$]pyrene, benz[${\alpha}$]anthracene, chrysene, etc. Therefore it is suspected that these chemicals act on estrogen receptor and reveal endocrine-disrupting effects. Recent attention has focused on causative chemicals of endocrine-disrupting effects. We examined the estrogenic activity of respirable diesel exhaust particulate matter derived from diesel powered vehicle. PM2.5 diesel exhaust of vehicle was collected using a high volume sampler equipped with a cascade impactor. Diesel exhaust samples were fractionated according to EPA methods. The presence of estrogenic and antiestrogenic chemicals in PM 2.5 diesel exhaust was determined using E-screen assay. To quantitatively assess the estrogenic and antiestrogenic activities in diesel exhaust particulate matter, estradiol equivalent concentration (bio-EEQ) was calculated by comparing the concentration response curve of the sample with those of the estrogen calibration curve. Weak estrogenic activities and strong antiestrogenic activities were detected in the crude extract and moderately polar fractions. Higher antiestrogenic potency was observed with higher EROD activities in aliphatic and aromatic compounds fraction. In conclusion, estrogenic/antiestrogenic-like activities were present in diesel exhaust particulate matter. However, the health consequences of this observation was unknown, the presence of these activities may contribute to and exacerbate adverse health effect evoked by diesel exhaust particulate matter.

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Estrogen reinforces barrier formation and protects against tumor necrosis factor alpha-induced barrier dysfunction in oral epithelial cells

  • Choi, Yun Sik;Baek, Keumjin;Choi, Youngnim
    • Journal of Periodontal and Implant Science
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    • v.48 no.5
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    • pp.284-294
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    • 2018
  • Purpose: Epithelial barrier dysfunction is involved in the pathophysiology of periodontitis and oral lichen planus. Estrogens have been shown to enhance the physical barrier function of intestinal and esophageal epithelia, and we aimed to investigate the effect of estradiol (E2) on the regulation of physical barrier and tight junction (TJ) proteins in human oral epithelial cell monolayers. Methods: HOK-16B cell monolayers cultured on transwells were treated with E2, an estrogen receptor (ER) antagonist (ICI 182,780), tumor necrosis factor alpha ($TNF{\alpha}$), or dexamethasone (Dexa), and the transepithelial electrical resistance (TER) was then measured. Cell proliferation was measured by the cell counting kit (CCK)-8 assay. The levels of TJ proteins and nuclear translocation of nuclear factor $(NF)-{\kappa}B$ were examined by confocal microscopy. Results: E2 treatment increased the TER and the levels of junctional adhesion molecule (JAM)-A and zonula occludens (ZO)-1 in a dose-dependent manner, without affecting cell proliferation during barrier formation. Treatment of the tight-junctioned cell monolayers with $TNF{\alpha}$ induced decreases in the TER and the levels of ZO-1 and nuclear translocation of $NF-{\kappa}B$. These $TNF{\alpha}-induced$ changes were inhibited by E2, and this effect was completely reversed by co-treatment with ICI 182,780. Furthermore, E2 and Dexa presented an additive effect on the epithelial barrier function. Conclusions: E2 reinforces the physical barrier of oral epithelial cells through the nuclear ER-dependent upregulation of TJ proteins. The protective effect of E2 on the $TNF{\alpha}-induced$ impairment of the epithelial barrier and its additive effect with Dexa suggest its potential use to treat oral inflammatory diseases involving epithelial barrier dysfunction.

Evaluation of Estrogenic Activity of Pumpkin Seed Extract using Recombinant Yeast Assay (재조합 효모를 이용한 호박씨 추출물의 에스트로겐 활성 평가)

  • Tahk, Hong-Min;Lee, Bog-Hieu;Rho, Sook-Nyung;Kim, Chun-Soo;Jung, Ji-Youn;Choi, Chang-Sun
    • Journal of Food Hygiene and Safety
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    • v.24 no.2
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    • pp.124-127
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    • 2009
  • The aim of this study is to evaluate the estrogenic activity of Cucurbita pepo seed extract which includes ${\beta}-sitosterol$ and other phytosterols. Sample was extracted from Cucurbita pepo seed by supercritical carbondioxide method and resuspended with ethanol. Estrogenic activity was measured by recombinant yeast assay which detects estrogenic activity using recombinant yeast with high level of estrogenic receptor. However, estrogenic activity of pumpkin seed extract was not found in this study. Based on this data, pumpkin seed extract will not cause estrogenic disturbance.

Induction of In Vitro Vitellogenin Synthesis by Bisphenol, Nonylphenol and Octylphenol in Chinese Minnow(Phoxinus oxycephalus) Hepatocytes

  • Park, Chang-Beom;Kim, Byung-Ho;Na, Oh-Soo;Choi, Young-Chan;Lee, Young-Don;Baek, Hae-Ja;Kim, Hyung-Bae;Akihiro Takemura
    • Animal cells and systems
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    • v.7 no.3
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    • pp.227-235
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    • 2003
  • Bisphenol A (BPA), nonylphenol (NP), and 4-tert-octylphenol (OP) are known endocrine disrupting chemicals (EDCs) with estrogenic activity in fish. This study compared the effects of BPA, NP and OP on in vitro vitellogenin (VTG) synthesis in primary cultures of hepatocytes of the Chinese minnow Phoxinus oxycephalus. The VTG secreted into the culture medium was measured using enzyme-linked immunosorbent assay (ELISA), which we developed in this study using an antibody prepared from homogenates of Chinese minnow egg. VTG synthesis was induced by estradiol-17$\beta$ ($E_2$) and phenols (BPA, NP and OP) treatment. $E_2$ at concentrations of 10$^{-6}$ M or higher increased VTG levels significantly (P < 0.05). Exposure to 10^5\;M\;BPA\;or\;10^-4$M NP and OPinduced in vitro VTG synthesis (P < 0.01). However, $10^-3$ M BPA, NP or OP did not induce VTG synthesis. These results suggest that SPA has the highest estrogenic potential in Chinese minnow hepatocytes. Tamoxifen, an anti-estrogen, drastically blocked the production of VTG by phenols (BPA, NP and OP) suggesting that phenols (BPA, NP and OP) may act via binding to estrogen receptor (ER) in Chinese minnow hepatocytes.

Synthetic Lead Compounds Modulate Activity of Large-conductance $Ca^{2+}$-activated Potassium Channels Expressed in Xenopus Oocytes

  • Ha, Tal-Soo;Kim, Yong-Chul;Park, Chul-Seung
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.42-42
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    • 2003
  • Large-conductance $Ca^{2+}$-activated potassium channels ($BK_{Ca}$ are a widely distributed and play key roles in various cell functions. In nerve cells, $BK_{Ca}$ channels shorten the duration of action potentials and block $Ca^{2+}$ entry thereby repolarizing excitable cells after excitation. $BK_{Ca}$ channel opening has been postulated to confer neuroprotection during stroke, and has attracted attention as a means for therapeutic intervention in asthma, hypertension, convulsions, and traumatic brain injury. Several natural and synthetic compounds including a steroid hormone, $\beta$-estradiol, have been identified as the activators of $BK_{Ca}$ channels. Based on the structural features of the previously reported activators of $BK_{Ca}$ channels, we designed several lead compounds, synthesized chemically, and tested their functional activity on cloned $BK_{Ca}$ channels. The $\alpha$ subunit of rat $BK_{Ca}$ channel was expressed alone or with different $\beta$ subunits in Xenopus oocytes and the effects of the compounds were tested electrophysiological means. One of the lead compounds affected the activity of the $\alpha$ subunit of $BK_{Ca}$ channel in a $\beta$ subunit-specific manner. While the activity of B $K_{ca}$ channel $\alpha$ subunit was Potentiated, the channel composed of $\alpha$ and $\beta$1 subunits were inhibited by this compound. We are currently investigating the mechanism of the $\beta$ subunit-dependent effects and planning to localize the receptor site of the lead compound.f the lead compound.

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St. John's Wort (Hypericum perforatum) stimulates human osteoblastic MG-63 cell proliferation and attenuates trabecular bone loss induced by ovariectomy

  • You, Mi-kyoung;Kim, Du-Woon;Jeong, Kyu-Shik;Bang, Mi-Ae;Kim, Hwan-Seon;Rhuy, Jin;Kim, Hyeon-A
    • Nutrition Research and Practice
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    • v.9 no.5
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    • pp.459-465
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    • 2015
  • BACKGROUND/OBJECFTIVES: The effect of St. John's Wort extract (SJW) on MG-63 cell proliferation and trabecular bone loss induced by ovariectomy was examined. MATERIALS/METHODS: Proliferation, expression of estrogen receptor (ER) ${\alpha}$ and ER ${\beta}$, and gene expressions of osteoprotegerin (OPG), osteocalcin (OC) and alkaline phosphatase (ALP) were examined in MG-63 cells treated with or without SJW. Ovariectomized rats were treated with SJW at the dose of 100 or 200 mg/kg/day, ${\beta}$-estradiol-3-benzoate (E2), or vehicle only (OVX-C), and sham operated rats were treated with vehicle only (Sham-C). Serum ALP and C-telopeptide (CTX), and femoral trabecular bone loss were examined. RESULTS: SJW increased MG-63 cell proliferation and expression of ER ${\alpha}$ and ER ${\beta}$, and positive effect was shown on gene expressions of ALP, OC and OPG. SJW also showed estrogen like effect on bone associated with slowing down in trabecular bone loss. Histopathology by H&E showed rats treated with SJW displayed denser structure in metaphyseal region of distal femur compared with rats in OVX-C. SJW was shown to reduce serum CTX in OVX rats. CONCLUSION: The present study provides new insight in preventing estrogen deficiency induced bone loss of SJW and possibility for its application in bone health supplement.

Trigonella Goenum-Graecum Seed Extract Alleviates Menopausal Symptoms and Osteoporosis in Ovariectomized Rats (호로파(葫蘆巴) 종자 추출물이 난소 절제술을 받은 쥐에서 갱년기 증상 및 골다공증에 미치는 영향)

  • Min Ju Kim;Mi-Rae Shin;Hak Joo Choi;Seong-Soo Roh
    • The Korea Journal of Herbology
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    • v.39 no.3
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    • pp.85-95
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    • 2024
  • Objectives : We proposed the hypothesis that administering Trigonella foenum-graecum seed extract (TSE) could alleviate menopausal symptoms and osteoporosis resulting from estrogen deficiency. Methods : Ovariectomized (OVX) rats were administered TSE at doses of 300 or 600 mg/kg body weight for 8 weeks, followed by measurement of serum lipid profile and serum bone markers using ELISA kits. Additionally, analysis of related genes in the femur and uterus was performed using Western blot and real-time PCR. Additionally, micro-CT analysis was performed to investigate the protective effect of TSE against bone loss due to oophorectomy. Results : The administration of TSE led to significant reductions in triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and glucose levels in the serum of OVX rats. Furthermore, TSE increased estradiol levels in the serum and notably improved the levels of biochemical markers associated with bone metabolism. Additionally, TSE exerted significant regulatory effects on the mRNA levels of alkaline phosphatase (ALP) and receptor activator of nuclear factor kappa-B ligand (RANKL)-genes closely associated with bone metabolism in the femur. TSE also demonstrated pronounced effects on uterine tissue, with improvements observed in gene expression related to estrogen receptors. Conclusion : Our findings confirm the efficacy of TSE in ameliorating menopause symptoms by modulating elements associated with both bone and lipid metabolism in the serum, uterine tissue, and femur of OVX rats. The present findings suggest that TSE may offer potential therapeutic effects for symptoms related to menopause and osteoporosis in females.

A Study on the Estrogenicity of Korean Arrowroot (Pueraria thunbergiana) (한국산 칡의 Estrogen 활성에 관한 연구)

  • Kim, So-Jung;Park, Chul;Kim, Hae-Gyoung;Shin, Wan-Chul;Choe, Suck-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.1
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    • pp.16-21
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    • 2004
  • To assess the estrogenicities of Korean arrowroot (Pueraria thunbergiana) the contents of nine phytochemicals which are known to present were analyzed by HPLC. Also the estrogenecities of these phytochemicals were assayed using estrogen receptor dependent transcriptional expression assay. Daidzein and puerarin are major compounds in arrowroot, which were contained in the order of: root>stem>leaf>flower>seed. Among the assayed phytochemicals daidzein, genistein, biochanin A, formononetin, puerarin and genistin were highly estrogenic. The total estrogenicities in different parts of arrowroot and those by regions in Korea were also assessed. Roots had the highest estrogenic effects. The estrogenicities also were shown in stem and leaf. The differences in the estrogenicities of arrowroots by regions in Korea were shown. These results demonstrated that the estrogenic phytochemicals content was the highest in Korean arrowroot and also present in stem and leaf.