• Toxicological Research
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• v.16 no.2
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• pp.109-116
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• 2000

The purposes of our study were to optimize the conditions of the screening and testing methods for endocrine disruptors, to characterize these assays using several compounds with well-defined endocrine activity, and to compare the sensitivity between these assays currently undergoing validation. Two in vitro test systems, MCF-7 cells proliferation (E-screen assay) and competitive binding to estrogen receptors (ER) were selected to evaluate the estrogenic effects. 17$\beta$-Estradiol (E2) and diethylstilbestrol (DES) were used as a positive control in vitro test. Also, E2 and ethinyl estradiol (EE) were used as a positive control in vivo uterotrophic assay. In in vitro test, E2 and DES showed a strong estrogenic response at concentration of 1.0 nM. In uterotrophic assay, E2 (0.3 $\mu\textrm{g}$/kg) and EE (0.3 $\mu\textrm{g}$/kg) produced a significant increase in uterus and vagina weight in both immature and ovariectomized rats. Although we did not com-pared the specificity between in vivo and in vitro assays, these assay systems may serve as a good tool for endocrine disruptors screening methods. Our data indicate that these assay systems exhibit some difference in their sensitivity to the same estrogenic compounds. Therefore, as a first rapid screening assay for estrogenic activity qf unknown chemicals, at least two assay systems should probably be carried out with a view of high sensitivity and standardization conditions. Also, a careful validation tests are necessary to obtain a reasonable degree of reproducibility.

• 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.

• 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.

• Proceedings of the Korean Society of Toxicology Conference
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• 2005.05a
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• pp.107-107
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• 2005

• Korean journal of food and cookery science
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• v.21 no.6 s.90
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• pp.769-775
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• 2005

In this study we isolate substances to serve as dietary resources in order to replace the female hormone. Silkworm (Bombyx mori) is one of the most attractive hosts for large-scale production of eukaryotic proteins which have been proven safe as a dietary resource. We report on the estrogenicity of a mixture of silkworm pupa and herbs (Ginseng,Ulkeum, and Hasuo) using the immature rat uterotrophic assay in vivo. Silkworm pupa aqueousextract (KW) and silkworm oil extract (KO) induced effects on the immature rat uterotrophic assay. KO showed neither positive uterotrophic response nor inhibition on E2 induced effect, while KW and MK (mixture of KW and herbs) showed both of the effects. It is concluded that ethanol extracts from silkworm might be a good, therapeutic, natural product for hormone-deficient diseases.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.149-149
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• 2003

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.149-149
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• 2003

It is well known that many pesticides possess hormonal activity, and thus have been classified as endocrine disruptors. Currently, pyrethroid insecticides are in worldwide use to control in door pests, providing potential for environmental exposure. A few studies of hormonal activities of these pyrethroid insecticides, however, have been reported, and are controversial between studies.(omitted)

• Journal of Ginseng Research
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• v.47 no.3
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• pp.385-389
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• 2023

Background: Ginseng has been used as a traditional medicine for treatment of many diseases and for general health maintenance. Previously, we showed that ginseng did not demonstrate estrogenic property in ovariectomized mouse model. However, it is still possible that disruption of steroidogenesis leading to indirect hormonal activity. Methods: The hormonal activities were examined in compliance with OECD guidelines for detecting endocrine disrupting chemicals: test guideline (TG) No. 456 (an in vitro assay method for detecting steroidogenesis property) and TG No. 440 (an in vivo short-term screening method for chemicals with uterotrophic property). Results: Korean Red Ginseng (KRG) and ginsenosides Rb1, Rg1, and Rg3 did not interfere with estrogen and testosterone hormone synthesis as examined in H295 cells according to TG 456. KRG treatment to ovariectomized mice did not show a significant change in uterine weight. In addition, serum estrogen and testosterone levels were not change by KRG intake. Conclusion: These results clearly demonstrate that there is no steroidogenic activity associated with KRG and no disruption of the hypothalamic-pituitary-gonadal axis by KRG. Additional tests will be performed in pursuit of cellular molecular targets of ginseng to manifest mode of action.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.11a
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• pp.166-166
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• 2002

• Toxicological Research
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• v.21 no.1
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• pp.31-37
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• 2005

The inhibitory activity against bisphenol-A (BPA), one of well-known endocrine disrupters was examined with the water extracts prepared from the Stem Bark of Syringa velutina (SBS). In this study, we have investigated the effect of SBS on the toxicity caused by BPA in human breast cancer cell line, MCF-7 cells and immature Sprague-Dawley rats. In the estrogen receptor-mediated proliferation assay using MCF-7 cells, BPA (16 ng/ml) induced the cell proliferation, but the water extract of SBS inhibited BPA-induced cell proliferation in a dose-dependent manner. These results are associated with PARP degradation and specific cleavage of anti-apoptotic protein Bcl-2 of apoptotic regulatory factors. Additionally, the BPA (400 mg/100 g) significantly induced the increase of the uterine and virginal weights, while SBS (50 mg/100 g) showed the inhibitory action against BPA, i.e. caused the increase of estrogen-related organ weights in immature rat uterotrophic assay. Taken together, the present data suggest that SBS may have anti-toxicity activities against BPA in vitro and in vivo systems. SBS may be capable of inhibiting adverse effects of BPA such as reproductive disorder.