• Korean Journal of Veterinary Research
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• v.45 no.4
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• pp.545-552
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• 2005

The major protocol features of the rodent uterotrophic assay have been evaluated using a range of reference chemicals. The protocol variables considered include the selection of the test species and route of chemical administration, the age of the test animals, the maintenance diet used, and the specificity of the assay for estrogens. The rodents were ovariectomized under general anesthesia via bilateral flank incisions and randomly assigned to groups of 5 animals. Chemicals were DEHP, DBP, BPA and NP, were injected sc once daily with combinations of chemicals treatments for 3 days. In the results, the reported estrogenic chemicals DEHP and DBP were both negative in the single dose treatments. But, in the combinations of chemicals treatments, DEHP and DBP increased in bud number of mammary gland. Treatment of ovariectomized mice with combinations of other chemicals resulted in uterine and vaginal hyperplasia. The additive estrogenic effects were seen with the combinations of $17{\beta}$-Bestradiol and DBP treatment. the competitive estrogenic effects were seen with the combinations of $17{\beta}$-Bestradiol and nonylphenol, $17{\beta}$-Bestradiol and bisphenol-A treatments. These results offers a sysmatic and mechanistically informative approach to assessing estrogenicity. it provides a useful profile of activity using a reasonable amount of resources and is compatible with the study of individual chemicals as well as the investigation of interactions among combinations of chemicals. The results described illustrate the intrinsic complexity of evaluating chemicals for estrogenic activities and conform the need for rigorous attention to experimental design and criteria for assessing estrogenic activity.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.2
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• pp.86-92
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• 2007

In this study, we tried to quantitatively study the distribution of estrogenic activity in sediment from Gwangyang Bay by E-screen assay. Besides, we compared the estrogenic activity and the concentration of chemical pollutants. The highest estrogenic activity was recorded at the stations(GY6 and GY8) close to industrial complex and the river mouth of Seomjin. These results obtained from the E-screen assay similar to those of simultaneous analytical detection of 310 chemicals. In particular, GY6 and GY8 sites are confirmed as the full agonist sites because of their RPE values were over 90% having strong estrogenic effect. Also, their EEQ(Estradiol Equivalency Quantity) values are 35.6 ng/g and 14.6 ng/g, low than that of other sites, and these results suggests that have relatively high estrogenic efficiency in Gwangyang Bay. From these results, we can estimate that the stations close to industrial complex and the river mouth of Seomjin are major sources of endocrine disrupter in Gwangyang Bay. On the other hand, when we tried to compare the endocrine disrupter activity and $COD_{Mn}$ value, that is not correlated.

• Molecular & Cellular Toxicology
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• v.2 no.2
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• pp.106-113
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• 2006

Phthalate analogues are a plasticizer and solvent used in industry. Phthalates were classified in the category of "suspected" endocrine disruptors. The purpose of our study was to screen and elucidate the endocrine disrupting activity of seven phthalate analogues. E-screen assay was performed in MCF-7 human breast cancer cells with seven phthalate analogues. In this cell proliferation assay, benzyl butyl phthalate (BBP) and dibutyl phthalate (DBP) showed high estrogenic activity. Their relative proliferation efficiencies (RPE) were 109 and 106%, respectively. In vitro estrogen receptor (ER) binding assay, BBP, di-n-octyl phthalate (DOP) and dinonyl phthalate (DNP) showed weak relative binding affinity (RBA: 0.02%) compared to $17{\beta}-estradiol\;(E2)$ (RBA: 100%). In uterotrophic assay, E2 produced a significant increase, whereas four tested phthalate analogues had potential estrogenic effects in vitro did not increased in uterus weight in immature rats. From these results, we demonstrated that phthalate analogues exhibit weak estrogenic activity in vitro assays at high concentrations. Although phthalates induced an increase in MCF-7 cell proliferation by an estrogenic effect, they could not induce a uterus weight increase in vivo. From these, we may suggest that these phthalate analogues are easily metabolized to inactive forms in vivo. Further investigation in other in vitro and in vivo experimental systems might be required.

• Archives of Pharmacal Research
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• v.29 no.5
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• pp.354-362
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• 2006

Dietary flavonoids have attracted a great deal of attention as agents for preventing estrogen-related diseases, such as postmenopausal symptoms, and for reducing the risk of estrogen-dependent cancer. Kaempferol is one of the most commonly found dietary phytoestrogen. The aim of this study was to investigate the estrogenic and/or antiestrogenic effect of kaempferol, which can confirm its potency as a preventive agent against estrogen-related diseases. Kaempferol has both estrogenic and antiestrogenic activity, which are biphasic response on estrogen receptor. The estrogenic activity of kaempferol induced via ER-mediated pathway depending on $E_2$ concentration $(\leq\;10^{-12}M)$. Kaempferol $(10^{-5}\;M)$ also caused antiproliferative effect on MCF-7 cell in the presence of $E_2\;(10^{-11}\;M)$ and restored to the addition of excess $E_2\;(10^{-7}\;M)$, which confirms that antiproliferation of kaempferol was induced via ER-dependent pathway. However, at $10^{-4}\;M$, concentration higher than the concentrations at which the estrogenic effects of kaempferol are detected $(10^{-5}\;M)$, kaempferol induced strong antiproliferative effect, but were unaffected by the addition of excess $E_2\;(10^{-7}\;M)$ indicating that kaempferol exerts antiproliferation via ER-independent pathway. In particular, kaempferol blocked the focus formation induced by $E_2$, which confirms that kaempferol might inhibit the malignant transformation caused by estrogens. Therefore, we suggested that kaempferol might regulate a suitable level of estrogenic activity in the body and is expected to have potential beneficial effects in preventing estrogen imbalance diseases (breast cancer, osteoporosis, cardiovascular disease and etc.).

• The Korea Journal of Herbology
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• v.35 no.3
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• pp.1-8
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• 2020

Objectives : In this study, we examined the estrogenic activities and anti-osteo clastogenesis effects of PCE17, a mixture of PE (an extract of Puerariae Flos), and CE (an extract of Citri Unshius Pericarpium). Methods : The estrogenic effect of PCE17, PE and CE were examined by ER-β/ERE reporter gene assay and proliferation assay in 293 T and MCF-7 cells. The expression of estrogen-responsive gene and protein were checked by Real Time-PCR (RT-PCR) and Western blotting in MCF-7 cells. Inhibitory effect of PCE17, PE and CE on RANKL-induced osteoclast differentiation were evaluated by TRAP staining and RT-PCR in primary osteoclast precursors from rat bone marrow cells. Results : PCE17 and PE bind to ERs (estrogen receptors) and show estrogenic activities in 293T cells. They also stimulated the proliferation of MCF-7 cells and increased the expression of ER response gene, pS2. Tectorigenin, an active ingredient of PE, shows similar estrogenic activities in MCF-7 cells. PCE17 and CE inhibited RANKL-induced osteoclastogenesis in rat primary osteoclast precursor cells and down-regulated the osteoclast-specific genes of Nfatc1, Ctsk, and Acp5. Conclusions : In conclusion, PCE17 may have therapeutic potential in cases of menopause and osteoporosis.

• Korean Journal of Veterinary Research
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• v.46 no.1
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• pp.35-41
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• 2006

Vitellogenin (Vtg), a phospholipoglycoprotein precursor of egg yolk is synthesized and secreted from the liver in response to estrogens in female fish. Vtg is normally undetectable in the blood of male fish, but can be induced by exposure to chemicals possessing estrogenic activity. Thus, the presence of Vtg in blood of male fish can serve as a useful biomarker for assessing previous exposure to estrogenic compounds. In the present study, Vtg was abnormally expressed in Rhynchocypris oxycephalus using estradiol benzoate ($E_2$). As the result, it was found that the level of Vtg in blood from R. oxycephalus was increased by treated quantity of $E_2$ with dose-effect manner. Monoclonal antibodies were generated against Vtg of R. oxycephalus. The hybridoma were screened with an enzyme immunoassay for the production of specific anti-Vtg antibodies. Five positive cell lines with a high specificity were selected. Monoclonal antibodies against vtg of R. oxycephalus that was developed in this study, may be a useful bio-indicator for the detection of estrogenic contamination in the aquatic ecosystem.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.368-372
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• 2005

Phytoestrogens are non-steroidal compounds found in a variety of plants, which exert estrogenic effects in animals. In this study, the useful compounds of pomegranate as preliminarily research for the developing of natural estrogen supplement were determined. The estrogenic activity of phytoestrogens in the pomegranate was estimated by using the Yeast Estrogen Receptor and E-screen assay. Estrogenic activity of all pomegranate extracts in the Yest Estrogen Receptor assay were not significant difference at all concentration. Whereas peel extracts of Iranian and domestic red pomegranate are significantly enhanced in the E-screen assay. When various pomegranate extracts enzyme and acid hydrolyzed, three aglycones of phytoestrogen, kaempferol, quercetin and catechin were detected. Peel extract of domestic red pomegranste contained more than kaempferol(87.0 mg%), quercetin(172.8 mg%)) and catechin(956.8 mg%) than other extracts. These differences in concentrations of key phytoestrogens among various extracts seemed to be responsible for their differences in estrogenic activities. Among these three compound, kaempferol showed the highest MCF-7 cell enhancing efface.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.349-353
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• 2011

The ascomycete fungus Fusarium graminearum is an important plant pathogen responsible for Fusarium head blight in small grains and ear rot on maize. This fungus also produces the estrogenic metabolite, zearalenone (ZEA) that causes estrogenic disorders in humans and animals. Previously, we developed a conditional gene expression system for this fungus using a ZEA-inducible promoter (Pzear). In the present study, four other estrogenic compounds, including ${\beta}$-estradiol, estriol, estrone, and secoisolariciresinol, were screened as possible substitutes for ZEA in this system. Among them, ${\beta}$-estradiol was able to successfully induce the expression of a gene controlled by Pzear, while estrone was only able to partially induce its expression but the other two compounds were not effective. In combination, these results demonstrate that ${\beta}$-estradiol can replace ZEA in this conditional gene expression system, thereby eliminating the need to use the more expensive reagent, ZEA, and facilitating high-throughput functional analyses of F. graminearum in future studies.

• Journal of Life Science
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• v.9 no.2
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• pp.19-23
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• 1999

Bisphenol-A and related conpounds recently have been reported to be estrogenic since it has been demonstrared in laboratory stuides that they mimic the effects of estrogen. Bisphenol-A refered to as "environmental estrogen" are suspected of causing health effect in living body through disruption of endocdrine system. In this review, the occurrence, environmental fate, and biological effects of bisphenol-A are presented. To provide understanding to the potential for endocrine disruption due to environmental estrogen, the physiology of bisphenol-A mammalian and fish is also reviewed. For empty can, the migrationof bisphenol-A form food conducted epoxy coating was effected by the test conditions and it increased in order to water and 4% acetic acid. Extracts from foods packed in lacquer coated can also showed estrogenic activity. Bisphenol-A was found as a contaminant not only in the liquid food cans, but also in water autoclave in can. The used of coating certain food-packaging material may require closer scrutiny to determine when bisphenol-A contribute to advert exposure of consumers to estrogenic xenobiotics. Human breast cancer MCF cell added bisphenol-A cultivated to study the ability of bisphenol-A to elicit of bisphenol-A estrogenic bioresponse in this system. Bisphenol-A, similar to estradiol, induced PR activation in transiently transfected anterior and posterior pituitary cells.

• Toxicological Research
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• v.17
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• pp.313-317
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• 2001

The Ministry of Health and Welfare of Japan has set up six research groups concerning the endocrine disrupting chemicals. One of these projects was "A study on development of testing methodology for health effects due to exposure of environmental endocrine disruptors". In this paper, three topics are described. In OECD collaboration for pre-validation of uterotrophic assay, the most sensitive response to ethnyl estradiol was noted in the ovarectomized rats treated subcutaneously for 7 days. Secondly, it was suggested that changes of the serum $\alpha_{2u}$-globulin level may be a sensitive parameter for detecting the estrogenic activities of chemicals. Finally, development of the sexually dimorphic nucleus of preoptic area in the brain oj male rats was inhibited by the treatment with estrogenic chemicals, and their masculine behaviors and reproductive abilities were impaired after sexual maturation. In conclusion, these parameters are considered to be sensitive endpoints for testing estrogenic chemicals.chemicals.