• Journal of Environmental Health Sciences
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• v.38 no.6
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• pp.561-567
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• 2012

Objectives: Parabens are widely used as antimicrobial agents in pharmaceuticals and cosmetics as well as by the food industry. Parabens have been reported to show weak estrogenic activity and be related to health effects such as allergic reactions and skin and breast cancer. We evaluated an online solid phase extraction (SPE) method coupled with LC-MS/MS technique using free and conjugated parent parabens in human urine for assessing human exposure to parabens. Methods: We employed LC/MS/MS through online solid phase extraction and column-switching techniques and analyzed free and conjugated parabens as biomarkers of human exposure. Four major parabens, methyl-paraben (MP), ethyl-paraben (EP), propyl-paraben (PP) and butyl-paraben (BP), were analyzed. Method validation was performed by sensitivity, accuracy, precision and comparison of the results of online SPE with offline SPE. Results: The limits of detection (LOD) were in the range of 0.2-2 ng/mL, and actual limits of quantification (LOQ) were in the range of 0.7-6 ng/mL urine, depending upon the compound. Accuracy was in the range of 98.3-106.4%, and precision was in the range of 1.3-8.7% (CV) depending upon the compound. We found a good correlation between the results of analysis by online SPE method and that by off-line SPE method. Conclusions: The online SPE method showed proper LOD and validated accuracy, precision and good correlation with the offline method for analyzing parabens in urine.

• Toxicological Research
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• v.27 no.4
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• pp.253-259
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• 2011

Transforming growth factor ${\beta}$ (TGF-${\beta}$) is involved in cellular processes including growth, differentiation, apoptosis, migration, and homeostasis. Generally, TGF-${\beta}$ is the inhibitor of cell cycle progression and plays a role in enhancing the antagonistic effects of many growth factors. Unlike the antiproliferative effect of TGF-${\beta}$, E2, an endogeneous estrogen, is stimulating cell proliferation in the estrogen-dependent organs, which are mediated via the estrogen receptors, $ER{\alpha}$ and $ER{\beta}$, and may be considered as a critical risk factor in tumorigenesis of hormone-responsive cancers. Previous researches reported the cross-talk between estrogen/$ER{\alpha}$ and TGF-${\beta}$ pathway. Especially, based on the E2-mediated inhibition of TGF-${\beta}$ signaling, we examined the inhibition effect of 4-tert-octylphenol (OP) and 4-nonylphenol (NP), which are well known xenoestrogens in endocrine disrupting chemicals (EDCs), on TGF-${\beta}$ signaling via semi-quantitative reverse-transcription PCR. The treatment of E2, OP, or NP resulted in the downregulation of TGF-${\beta}$ receptor2 (TGF-${\beta}$ R2) in TGF-${\beta}$ signaling pathway. However, the expression level of TGF-${\beta}1$ and TGF-${\beta}$ receptor1 (TGF-${\beta}$ R1) genes was not altered. On the other hand, E2, OP, or NP upregulated the expression of a cell-cycle regulating gene, c-myc, which is a oncogene and a downstream target gene of TGF-${\beta}$ signaling pathway. As a result of downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc, E2, OP, or NP increased cell proliferation of BG-1 ovarian cancer cells. Taken together, these results suggest that E2 and these two EDCs may mediate cancer cell proliferation by inhibiting TGF-${\beta}$ signaling via the downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc oncogene. In addition, it can be inferred that these EDCs have the possibility of tumorigenesis in estrogen-responsive organs by certainly representing estrogenic effect in inhibiting TGF-${\beta}$ signaling.

• Journal of Life Science
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• v.13 no.4
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• pp.529-534
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• 2003

This study was done to investigated the phytosterol compositions of safflower (Carthamus tinctorius L.) seed. The phytoestrogen activity was also determined using CAT-ELISA Kit in ethanol extract of safflower seed. The phytosterol of safflower seeds was identified using gas chromatography-mass spectrometry after saponification of the oils. The phytosterol content and composition of safflower seed oils were 4% and identified stigmast-5-en-3-ol (3$\beta$, 24S)-form, ${\gamma}$-sitosterol (clionasterol) with Wiley MS spectrum library. The synergistic effect of human estrogen receptor (hER) has been investigated using a minimal chimeric promoters composed of the TATA region of the adenovirus-2 major late promoter (A22MLP) and two consensus perfectly polindromic Xenopus vitellogenin A2 gene estrogen responsive elements (XVEREl19). Transient transfection experiments in tile human breast adenocarcinoma cell line MCF-7, which is known to express the estrogen receptor endogenously, revealed that phytoestrogen from Carthamus tinctorius L. acts as estrogen. We have observed the transcriptional activities stimulated methanol and ethanol extract of safflower seed in MCF-7, were 0.43 and 0.37 respectively, compared to that by $\beta$-estradiol as 1.0. Our data showed that safflower seeds have estrogenic activity methanol and ethanol extracts and ethanol lower than that of $\beta$-estradiol. This result provides the first evidence that the beneficial effect of safflower seeds may be mediated, at least in part, by the stimulating effect of phytoestrogen ell bone-protecting.

• Environmental Mutagens and Carcinogens
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• v.23 no.3
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• pp.94-98
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• 2003

Quercetin and naringenin are representative flavonoids that not only exert anti estrogenic, cholesterol-lowering and antioxidant activities but also can modulate the metabolism of many xenobiotics. The activity of the specific form(s) of CYP450 is likely to be a major determinant of susceptibility to chemically induced carcinogenesis between which varies among between individuals due to different dietary habits as well as genetic characteristics. People consume cooked meat or fish together with various vegetables containing substantial amounts of quercetin and naringenin that can modify the enzyme activity of CYP1A2 to stimulate or to inhibit the mutagenic activities of HCAs. Heterocyclic amines (HCAs) produced by cooking meat products at high temperatures are promutagens that are activated by cytochrome P450 (CYP) lA2. Using a newly developed Salmonella typhimurium TA1538/1A2bc-b5 strain, we tested the effect of quercetin and naringenin on the mutagenicity of 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ). TA1538/1A2bc-b5 bears two plasmids, one expressing human CYP1A2 and NADPH-P450 reductase (NPR), and the other plasmid which expresses human cytochrome b5 (cyp b5). TA1538/1A2bc-b5 cells showed high activities of 7-ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-demethylase (MROD) associated with CYP1A2 and are very sensitive to mutagenesis induced by several HCAs. MeIQ was found to be the strongest mutagen among the HCAs tested in this system. Mutagenicity of MeIQ was enhanced 50 and 42% by quercetin at 0.1 and 1 mM, respectively, but suppressed 82% and 96% at 50 mM and 100 mM. Naringenin also increased the MeIQ-induced mutation about 37% and 22% at 0.1 and 1 mM, but suppressed it 32% and 63% at 50 mM and 100 mM concentrations, respectively, in TA 1538/1A2bc-b5 cells. Thus, they stimulated the MeIQ induced mutation at low concentrations, but strongly suppressed it at high concentrations. This biphasic effect of flavonoids was due to the stimulation or the inhibition of CYP1A2 activity in a dose-dependent manner judging by the activities of EROD or MROD in the Salmonella cells. Collectively, it is likely that the biphasic effects of quercetin and naringenin on the MeIQ-induced mutagenesis in S. typhimurium TA1538/CYP1A2bc-b5 were due to their differential modification of the CYP1A2 activity in these cells.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.2
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• pp.173-179
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• 2010

The antiestrogen tamoxifen is currently the most commonly used adjuvant treatment of breast cancer with antiestrogenic effect on mammary tissue. However, it is also associated with endometrial abnormalities, including hyperplasia, polyps, carcinoma, mostly interpreted as evidence of estrogenic effect on the endometrium. Previously, tamoxifen-associated polyp in breast cancer has been reported in the literature. Most studies had a long follow-up period and tamoxifen-associated polyp developed more than 1 year after tamoxifen treatment. In this case, we report an unusual case of rapid growing and multiple endometrial polyps that were developed only after 3 months' tamoxifen treatment in a postmenopausal breast cancer patient who received quadrant mastectomy with a brief review of literature.

• Development and Reproduction
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• v.21 no.2
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• pp.121-130
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• 2017

4-Nonylphenol (NP) is a surfactant that is a well-known and widespread estrogenic endocrine disrupting chemical (EDC). Although it has been known that the affinity of NP to ERs is low, it has been suggested that low-dose NP has toxicity. In the present study, the endocrine disrupting effects on reproduction, and the weight of gonads, epididymis, and uterus were evaluated with the chronic lower-dose NP exposing. This study was designed by following the OECD test guideline 443 and subjected to a complete necropsy. In male, NP had an effect on the weight of the testis and epididymis in both $F_0$ and $F_1$. In females, NP decreased the weight of ovary and uterus in $F_0$ but not in pre-pubertal $F_1$ pubs. Fertility of male and female in $F_0$ or $F_1$ was no related with NP administration. The number of caudal-epididymal sperm by body weight (BW) was not different between groups in both $F_0$ and $F_1$. Besides, the difference of the sperm number between generations was not detected. The number of ovulated oocytes was similar between groups in $F_0$, but significantly decreased in NP 50 group of $F_1$. The litter size and sex ratios of offspring in $F_1$ and $F_2$ were not different. The accumulated mating rate and gestation period were not affected by the NP administration. Those results shows that chronic lower-dose NP administration has an effect of endocrine disruptor on the weight of gonads and epididymis of $F_0$ and $F_1$ but not in reproduction. Based on the results, it is suggested that chronic lower-dose NP exposing causes endocrine disruption in the weight of gonad and epididymis but not in the reproductive ability of next generations.

• Development and Reproduction
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• v.10 no.3
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• pp.177-184
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• 2006

Retinol-binding protein(RBP) plays an important role in the specific transport of retinol to target cells through the blood stream in higher vertebrates. In order to clarify the effects of 4-nonylphenol(4-NP) on RBP mRNA expression in the rockfish, Sebastes schlegeli which is common in coastal waters of Korea and commercially important species, the cDNA library was constructed from the liver, and a partial fragment of the RBP gene was cloned. The deduced amino acid sequence from the RBP mRNA showed a high homology to the amino acid sequence from Sparus aurata(80%), Oncorhynchus mykiss(72%) or Anguilla anguilla(78%). Effects of 4-NP on RBP and vitellogenin(VTG) mRNA expression level in rockfish were examined by the northern blot analysis. In female and male rockfish injected with 4-NP(10 mg/kg BW, lower dose), there was no changes in the levels of VTG mRNA expression in the liver. The RBP mRNA levels, however, decreased at 48 hours after the injection in male. In the rockfish injected with 4-NP(25 mg/kg BW, higher dose), the level of VTG mRNA expression increased after 24 hours, regardless of sex. The level of RBP mRNA expression decreased at 48 hours after the injection in both sexes. These data indicate that estrogenic mimics such as 4-NP exhibit a contrasting effect on RBP and VTG gene expression in rockfish.

• Development and Reproduction
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• v.12 no.3
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• pp.275-281
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• 2008

Endocrine disrupting chemiclas (EDCs) such as bisphenol A (BPA) and nonylphenol (NP) have estrogenic activity and can alter reproduction in fish. In the present study, the effects of BPA and NP on in vitro steroid production from oocytes of maturation stage (oocyte diameter$\fallingdotseq$1.88 mm) from the greenling (Hexagrammos agrammus) were evaluated. Oocytes were incubated with different concentrations of BPA and NP (0.1, 1, 10, 100 and 1,000 ng/$m{\ell}$) in the presence or absence of 50 IU human chorionic gonadotropin (HCG) for 48 hours. After incubation, levels of $17{\alpha},\;20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}OHP$), estradiol-$17{\beta}(E_2)$ and testosterone (T) from incubated media were quantified by radioimmunoassay (RIA). In BPA treatment, 100 ng/$m{\ell}$ of BPA stimulated $E_2$ production regardless HCG supplement. Every concentration of BPA inhibited T production without HCG although 0.1 ng/$m{\ell}$ of BPA stimulated T production with HCG. In NP treatment, 10 ng/$m{\ell}$ of NP stimulated $17{\alpha}20{\beta}OHP$ and T production without HCG. 1 ng/$m{\ell}$ of NP inhibited $E_2$ production. Taken toghther, these results suggest that BPA might have weak estrogen-agonistic effect and NP has estrogenantagonistic effect at final oocyte maturation stage of H. agrammus.

• Journal of the Korean Chemical Society
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• v.60 no.2
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• pp.118-124
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• 2016

Parabens were commonly used for preventing the growth of microorganisms as preservatives in the pharmaceutical, cosmetic and food industry. Also, parabens are known endocrine disruptors because of their estrogenic effects on human. Parabens affect the endocrine system and show adverse effect such as, genital malformations, precocious puberty and testicular cancer in young children, infants and fetuses. In this study, we developed analytical method for four parabens (methyl paraben, ethyl paraben, propyl paraben, butyl paraben) in human breast milk which frequently consumed by newborn baby. The analytes were extracted using liquid-liquid extraction (LLE) after enzyme hydrolysis with protease and lipase, then quantitative analysis was performed by liquid chromatography tandem mass spectrometry (LC-MS/MS). The method validation results were as follows; the linearity of calibration curves were excellent with coefficient of determinations (r²) higher than 0.999, the limit of detections (LODs) were 0.019~0.044 ng/mL, the accuracies were 85.3~105.9% and the precisions were lower than 10%. The average concentration ± standard deviation of parabens in ten human breast milk sample were MP 0.660 ± 0.519 ng/mL, EP 1.631 ± 2.081 ng/mL and PP 0.326 ± 0.320 ng/mL, and BP was not detected.

• Journal of Nutrition and Health
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• v.36 no.6
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• pp.603-612
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• 2003

Postmenopausal women are at an increased risk of developing coronary artery disease. This is due to primarily dyslipidemia accompanying the loss of estrogen secretion. Soy isoflavones are known to have weak estrogenic effects. The purpose of this study is to investigate whether isoflavone supplement improves the risk of cardiovascular disease in hypercholesterolemic postmenopausal women. Subjects consisted of 39 Korean postmenopausal women with hypercholesterolemia (total cholesterol $\geq$ 200 mg/㎗ or LDL cholesterol $\geq$ 130 mg/㎗). Subjects were divided into 2 groups; placebo group (PG), isoflavone supplement group (IG). During 12 weeks, subjects were given placebo and 80mg isoflavone daily. Anthropometric measurement, blood sample analysis and dietary intake measurement were taken at baseline and after 12 weeks. After 12 weeks, systolic blood pressure was decreased significantly (p ＜ 0.01) and plasma HDL cholesterol level was increased significantly (p ＜ 0.05) in IG. But there were no significant changes in plasma total cholesterol, LDL cholesterol and triglyceride levels after isoflavone supplementation. There was a negative correlation between initial plasma HDL cholesterol level and the extent of plasma HDL cholesterol reduction in IG (r＝-0.572, p＝0.012). Atherogenic index (AI), total-/LDL- cholesterol ratio and LDL/HDL cholesterol ratio were improved significantly after isoflavone supplementation. In subjects whose initial plasma LDL cholesterol level were above 160 mg/㎗, plasma malondialdehyde (MDA) level were decreased and total antioxidant status (TAS) were increased significantly after isoflavone supplement (p ＜ 0.05). However there were no significant changes in flow-mediated dilator (FMD), the marker of endothelium-dependent vasodilation and nitroglycerine-mediated dilator (NMD), the marker of endothelium-independent vasodilation and the extent of DNA damage after isoflavone supplement. In conclusion, these results indicate that isoflavone supplement may decrease the risk of cardiovascular disease via improving blood pressure, HDL cholesterol level and AI in hypercholesterolemic postmenopausal women. Futhermore, in case of subjects with elevated LDL cholesterol level, isoflavone supplementation may have more antiatherogenic effects via improving antioxidant status.