• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.964-969
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• 2000

Di-(2-ethylhexyl) adipate(DEHA) has been used extensively as a plasticizer in the manufacture of plastic products such as PVC films. Though, phthalate esters plasticizers have been known to induce endocrine system-mediated responses, few studies have been conducted for the screening of estrogenic activity of DEHA, an adipate plasticizer. This study was initiated to evaluate the estrogenic activity of DEHA by in vitro E-screen assay and in vivo uterotrophic assay. MCF-7 human breast cancer cells were treated with $DEHA(5{\times}10^{-9}{\sim}5{\times}10^{-4}\;M)$, for 144 hr, and cell proliferation was determined by sulforhodamine B(SRB) assay. DEHA dissolved in corn oil was administered subcutaneously to ovariectomized(OVX) female Sprague-Dawley rats at dosage levels of 0, 2, 20 and 200 mg/kg/day for three consecutive days. Rats were sacrificed 24 hr after final treatment and vagina and uterus(wet and blotted) weights were obtained. E-screen assayed DEHA did not generate cell proliferation at treated concentrations$(5{\times}10^{-9}{\sim}5{\times}10^{-4}\;M)$, whereas 17 ${\beta}-estradiol$(E2), the positive control, induced cell proliferation at low concentrations$(5{\times}10^{-14}{\sim}5{\times}10^{-9}\;M)$. In the uterotrophic assay, DEHA did not change vagina and uterus(wet and blotted) weights at dosage levels up to 200 mg/kg/day treatment. These results demonstrated that DEHA did not exhibit the estrogenic activity as determined by in vitro E-screen assay and in vivo uterotrophic assay.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1769-1775
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• 2010

Menopause is often associated with the incidence of several chronic diseases including osteoporosis, cardiovascular disease, and obesity. The purpose of this study was designed to evaluate the possibility of osteoporosis prevention in postmenopausal women. In this study, we investigated the effects of Ecklonia stolonifera (ES) extracts on bone turnover markers in ovariectomized rats. For this study, the following four groups of 9-week-old Sprague-Dawley rats were evaluated over 6 weeks: normal rats (SHAM), ovariectomized rats (OVX-CON) and ovariectomized rats that were treated with ES extracts. We measured the osteocalcin and C-telopeptide of collagen cross-links (CTx) content, enzyme ALP activity in serum and collagen content in the cartilage, bone, skin and lungs. We found that the levels of indicators of bone metabolism such as alkaline phosphatase (ALP), osteocalcin and CTx were lower in rats in the ES extract group than the OVX-CON group. In addition, the collagen contents in the bone, cartilage, skin and lungs decreased in response to ovariectomy, but the levels of collagen were greater in the bone of rats that were treated with ES extract than in the bone of rats in the OVX-CON group. These results suggest that the ES may be an effective functional food to prevent osteoporosis in postmenopausal women.

• Journal of Life Science
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• v.18 no.11
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• pp.1578-1583
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• 2008

The purpose of this study was to investigate the effects of sea tangle (ST) extracts on formation of collagen and collagen cross-link in ovariectomized rats. From day 3 until 42 after the ovariectomy, Sprague-Dawley female rats were randomly assigned to the following groups: sham-operated rats(Sham), ovariectomized control rats (OVX-control), ovariectomized rats supplemented with ST at 50 mg/kg bw/day (OVX-ST50), 200 mg/kg bw/day (OVX-ST200). The ethanol extraxcr of ST was orally administrated at 1 ml/day. The change of collagen content was investigated in bone, cartilage and skin of ovariectomized rats. Effects of ST extract on the amount of collagen was examined by measuring the hydroxyproline, which is a specific amino acid existing in collagen. The ovariectomy resulted in a decrease in the levels of collagen content in bone and cartilage tissues. However, the supplementation with the sea tangle extract prevented the decrease in the collagen level in bone and cartilage tissues. Pyridinoline is pyridinium cross-link formed in the mature form of collagen from lysine and hydroxylysine residues. Although the pyridinoline content in bone collagen declined after ovariectomy, it was recovered to a normal level of Sham group by the supplementation with the ST extracts. In addition, the deoxypyridinoline content in bone collagen, which was reduced after ovariectomy was enhanced to normal level by the supplementation with the ST extract. These results was consistent with the conclusions based on estrogenic activities of ST.

• The Korean Journal of Pesticide Science
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• v.8 no.2
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• pp.95-102
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• 2004

The present study was conducted to test and evaluate estrogenic effect of 17 pesticides including benomy1 and carbaryl, being suspected as endocrine disrupting chemicals. For estrogenic effect examination, luciferase assay were achieved with human ovarian cancer cell, BG1Luc4E2. Estrogenic effects of cypermethrin, dicofol, endosulfan, esfenvalerate, and fenvalerate were observed at the concentration of $10^{-5}$ M by estrogen receptor binding assay. Relative luciferase potency and relative luciferase effects compared with $10^{-10}$ M 17 $\beta$-estradiol were $10^{-5}$, 56% for dicofol, and $10^{-5}$, 72% for endosulfan, respectively. Estimated maximum daily intake for pesticides was calculated from maximum residue limit of agricultural commodity and food consumption was 1.2298 mg/person. Theoretically calculated blood estrogen level from dietary intake for pesticides based on MRL in Korea, 3.075 ng/L was equivalent to 15% of estrogen concentration in normal blood, but practical monitoring data, 0.01938 ng/L was equal to 0.09693% of estrogen concentration in normal blood.

• Journal of Life Science
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• v.23 no.12
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• pp.1501-1508
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• 2013

This study investigated antioxidant activity and the lipid content of serum for the possible outcome of improving the activity of Ishige okamurae extracts in ovariectomized rats. The antioxidant effects of an Ishige okamurae water extract and an Ishige okamurae ethanol extract were measured by evaluating DPPH free radical scavenging activity and SOD-like activity. Fifty, seven-week old female Sprague Dawley rats were randomly assigned to five groups as follows: sham-operated rats (SHAM), ovariectomized rats (OVX-CON), ovariectomized rats that were treated with 17-beta-estradiol (200 ${\mu}g/kg/day$), and ovariectomized rats that were treated with Ishige okamurae extracts (50 mg/kg/day and 200 mg/kg/day, respectively). The diets were fed to the rats for seven weeks after ovariectomy. The antioxidant activities of the water and ethanol extracts of Ishige okamurae increased in a dose-dependent manner, and the ethanol extract was found to be higher than the water extract. Therefore, we examined the effect of an Ishige okamurae ethanol extract on total serum cholesterol, triglycerides, HDL-cholesterol, and LDL-cholesterol levels, and anti-platelet aggregation. The total-cholesterol and triglyceride content of the serum increased in the OVX-CON group compared to the SHAM group, but supplementation with the Ishige okamurae ethanol extract caused these factors to decrease. Notably, the serum LDL-cholesterol concentration in the supplemented 200 mg/kg/day Ishige okamurae ethanol extract group was significantly more reduced than it was in the OVX-CON group. In addition, the platelet aggregation ability was lower in the groups treated with Ishige okamurae than it was in the OVX-CON group. According to these results, the effects of Ishige okamurae extract on serum lipid content in ovariectomized rats were illuminated.

• Journal of Life Science
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• v.32 no.3
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• pp.256-262
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• 2022

Oxysterols are oxygenated metabolites of cholesterol generated by serial enzymatic reactions during bile acid synthesis. Similar to cholesterol, oxysterols move rapidly to the intracellular region and modulate various cellular processes, such as immune cell responses, lipid metabolism, and cholesterol homeostasis. Different nuclear transcription factors, such as glucocorticoid, estrogen, and liver X receptors, can be modulated by oxysterols in multiple tissues. The most abundant oxysterol, 27-hydroxycholesterol (27-OHC), is a well-known selective modulator that can either activate or suppress estrogen receptor activity in a tissue-specific manner. The contribution of 27-OHC in atherosclerosis development is apparent because a large amount of it is found in atherosclerotic plaques, accelerating the transformation of macrophages into foam cells that uptake extracellular modified lipids. According to previous studies, however, there are opposing opinions about how 27-OHC affects lipid and cholesterol metabolism in metabolic organs, including the liver and adipose tissue. In particular, the effects of 27-OHC on lipid metabolism are entirely different between in vitro and in vivo conditions, suggesting that understanding the physiology of this oxysterol requires a sophisticated approach. This review summarizes the potential effects of 27-OHC in atherosclerosis and metabolic syndromes with a special discussion of its role in metabolic tissues.

• Environmental Analysis Health and Toxicology
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• v.23 no.3
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• pp.179-186
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• 2008

내분비계 장애물질 중 에스트로겐성 특성을 지닌 것으로 알려진 bisphenol A에 폭로되었을 때에 나타나는 이상 증상과 selenoprotein N 결핍 증상은 유사성이 있는 것으로 관찰되었다. 이에 본 연구에서는 bisphenol A에 폭로된 생물체의 selenoprotein N 유전자 발현에 영향을 미치는지에 관해 연구하였다. 실험동물은 zebrafish (Danio rerio, wild type)의 수정란을 사용하였다. Zebrafish의 수정란은 서로 다른 농도의 bisphenol A (0.1, 1, 10 ppm)에 노출하였다. 각각의 폭로 환경에서 부화된 치어를 시료로 selenoprotein N 유전자 발현을 RT-PCR방법에 의해 알아보았다. 그 결과, bisphenol A는 척추이상과 심장이상이 나타나 selenoprotein N 이상시 나타나는 현상과 유사성을 보였다. Selenoprotein N 유전자 발현은 bisphenol A 폭로 농도가 높아짐에 따라 유전자 발현 농도가 낮아지는 것으로 관찰되었다. 특히 1 ppm 농도에서는 대조군이나 0.1 ppm 농도보다 catalase의 활성이 높게 나타나 특정 농도에서 bisphenol A에 의한 영향이 나타나는 것을 알 수 있었다.

• Journal of Environmental Science International
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• v.13 no.6
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• pp.591-597
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• 2004

In this study, sixty chemicals including 47 pesticides were screened for estrogenic activity using E-screen assay. MCF-7 cell, used in E-screen assay, is known to be proliferated by addition of estrogenic chemicals. Eight of the measured pesticides showed estrogenic activity at the concentration range of 100-10,000nM. Their relative proliferative effect (RPE) and the relative proliferative potency (RPP) were 20-65% and 0.01-1.0%, respectively, when compared with 1.0nM of $\beta-Estradiol-17-acetate(E_{2}).$ DDVP and diazinone showed most strong estrogenic potency(RPP; 1.0%) and effect(RPE; 65%) of the eight pesticides. These results are in agreement with estrogenic activity of bisphenol A is known as a positive endocrine disrupter. Also, in this study, paraquat, DDVP, 4-chloro-3-methylphenol, 2,4,6-trichlorophenol and diazinon of the measured pesticides are estimated to estrogenic chemical.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2002.10a
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• pp.119-121
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• 2002

인류는 1,500 만 종류에 달하는 화학물질을 합성 혹은 분리ㆍ동정 해왔다. 그리고 현재 약 10 만 종류 정도의 화학물질이 상업적으로 이용되고 있다. 이들 화학물질 중에 유기염소화합물, 공업용화합물, 농약류, 유기취소(bromine)화합물, 중금속 및 유기금속, 식물 및 합성에스트로겐 등을 포함한 수십 종의 화합물이 내분비계장애물질 (Endocrine Disruptors, EDs)로서 생각, 혹은 의심되고 있다. 그러나, 대부분의 다른 화합물에 대해서는 그것들이 내분비계장애 작용을 가지고 있는지에 대한 충분한 지견이 얻어지지 않고 있어 이들 화학물질의 내분비계장애 작용을 평가하기 위해서는 신속 또는 간편한 검출계의 확립은 매우 중요하다.

• Korean Journal of Microbiology
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• v.44 no.3
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• pp.199-202
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• 2008

A white rot fungus Irpex lacteus produced lignin degrading enzymes, which showed degrading activity against various recalcitrant compounds. However, laccase, one of the lignin degrading enzymes, was too low to be assayed by spectrophotometry using o-tolidine as the chromogenic substrate in this fungus under various culture conditions. A laccase expression vector was constructed using a cDNA from Phlebia tremellosa with the constitutively expressed promoter of glyceraldehydes-3-phosphate dehydrogenase gene, and introduced into I. lacteus by the restriction enzyme mediated integration transformation through the protoplast-$CaCl_2$ procedure. Two transformants showed highly increased laccase activities at the early growth phase in the minimal liquid medium, and they not only degraded bisphenol A, a notorious endocrine disrupting chemical, but also removed the estrogenic activity effectively.