• Korean Journal of Environmental Biology
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• v.33 no.4
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• pp.361-374
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• 2015

Endocirne disruptors (EDs) can cause fertility decrease, developmental disorder, and even cancer in animals. Until 90's, EDs were used in various synthetic products including paints, coatings, detergents, plastics, and plasticizers. Currently, in several countries, the production, trade and use of EDs or EDs-suspected chemicals have been regulated while activity to screen the alternatives for EDs including bisphenol-A, phthalate and nonylphenol is active. Although various toxicity test method was developed and applied for screening of alternatives, however, the safety of alternatives has been not fully demonstrated. Some alternatives have high structural similarity with existing EDs, raising the possible risk of endocrine disruption by alternatives. In an effort to develop the safe alternatives, we reviewed the effects of EDs such as bisphenol-A, phthalates, nonylphenol and their substituents. In addition, in-silico analysis for endocrine disrupting activities of some alternatives was presented.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.277-280
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• 2010

Bisphenol A (BPA) is an endocrine disruptor frequently used in food containers, including epoxy resin and polycarbonates. BPA concentrations were monitored by high performance liquid chromatography (HPLC) under photosensitization of riboflavin (RF), methylene blue (MB), rose bengal (RB), or titanium dioxide ($TiO_2$) and the involvement of singlet oxygen was determined using sodium azide ($NaN_3$). The stability of BPA decreased significantly in the order of RF, RB, and MB photosensitization (p<0.05), while the concentration of BPA in samples with $TiO_2$ was not significantly different from that of control samples without photosensitizers under light (p>0.05). The stability of BPA decreased in an MB concentration-dependent manner and increased as the concentration of added $NaN_3$ increased, implying that singlet oxygen was involved in the photodegradation of BPA during MB photosensitization. The results of this study may help control the BPA content in foods or the environments using photosensitized oxidation and visible light irradiation.

• Korean Journal of Materials Research
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• v.2 no.3
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• pp.191-196
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• 1992

The new epoxy resin, diglycidyl ether of bisphenol A(DGEBA)/4, 4'-methylene dianiline (MDA)/succinonitrile system, containing the reactive additive succionitrile was investigated through the impact test and the stress-strain test on the basis of the behavior of cure reaction and the cure mechanism. The new epoxy resin system, having the different succinonitrile contents, were cured at $80^{\circ}C$for 1.5 hour and then in order to cure completely at $150^{\circ}C$ for 1 hour. It was shown that as the succinonitrile content increased, impact strength was gradually increased, tensile strength was decreased, almost constantly Young's modulus was sustained and elongation was increased until the succinonitrile content was increased to 10phr, and then decreased. From the experimental results, it can be concluded that the chemical bonding length between the main chains was extended by adding the reactive additive succinonitrile. It was also found that the flexibility of epoxy resin was improved by adding the succinonitrile.

• Korean Journal of Environmental Biology
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• v.25 no.1
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• pp.66-71
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• 2007

The fourth instar larvae of C. riparius were treated with potential endocrine disruption chemicals (EDCs) such as bisphenol A (BPA) and 4-nonylphenol and the effects of morphological abnormalities were observed. The deformities of the mentum following exposure to EDCs showed the smooth tooth, the loss of tooth and deformed tooth. The incidence rates of the mentum deformity were associated with chemicals: BPA $31{\sim}90%$, and 4-nonlyphenol was $40{\sim}80%$. As the concentration of BPA increased, the incidence of deformed mentum was dose dependent. While the incidences of deformed mentum following exposure to 4-nonlyphenol was not associated with their concentrations. The deformed MLT observed smooth or round tooth and the deformity of LT showed loss of one or more than tooth. Also, the MIX type was usually smooth or loss tooth. The abundance of deformity type for the mentum showed MIX (MLT+LT) > LT (lateral teeth) > MLT (median lateral teeth).

• Journal of Environmental Health Sciences
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• v.30 no.2
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• pp.71-78
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• 2004

This study was performed to evaluate developmental and estrogenic activity of bisphenol A (BPA) and butyl benzyl phthalate (BBP) to the second generation of Sprague-Dawley rats ingested during gestational or lactational periods. Rats were given BPA 20$\mu\textrm{g}$/kg BBP 100mg/kg of pregnancy or lactation periods. Maternal body weight and neonatal body weight were recorded. The rats were sacrificed on day 21 after birth. Reproductive organs of dam and neonate were utilized for receptor binding assay. The plasma concentrations of BPA and MBep, one of the major metabolites of BBP were analyzed with HPLC. The co-administration of BPA and BBP induced slow weight gain compared with single administration in dams. Also, such mixture induced low neonatal body weights in next generation. The dams treated with BPA and BBP during lactational periods showed significant organ weight changes in liver and spleen. The dams exposed during lactational periods showed significant organ weight changes not only in liver and spleen but also in kidney, uterus and ovary. The F1 female rats exposed during lactation periods showed significant organ weight changes in liver, spleen, ovary. The F1 male rats showed significant organ weight changes in liver, kidney, epididymis, vesicular glands, prostate. However, no clear synergistic effects of BPA and BBP were noted. There was no significantly different ER$\alpha$ expression pattern between control and treated groups. However, ER$\alpha$ expression were increased in F1 male testis and female uterus. PI male showed distinct ER$\alpha$ expression, especially in the group of lactational combined exposure. Synergistic ER$\alpha$ expression was found by combined treatment of BPA and BBP. We could not find any evidences of synergistic effects on BPA and/or BBP combined administration on dams and their fetuses, except in ER$\alpha$ expression of F1 male.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1095-1104
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• 2018

The adsorption characteristics of bisphenol A (BPA) were investigated using activated carbon based on waste citrus peel (which is abandoned in large quantities in Jeju Island), denoted as WCP-AC, and surface-modified with various $P_2O_5$ concentrations (WCP-SM-AC). Moreover, coconut-based activated carbon (which is marketed in large amounts) was surface-modified in an identical manner for comparison. The adsorption equilibrium of BPA using the activated carbons before and after surface modification was obtained at nearly 48 h. The adsorption process of BPA by activated carbons and surface-modified activated carbons was well-described by the pseudo second-order kinetic model. The experimental data in the adsorption isotherm followed the Langmuir isotherm model. With increasing $P_2O_5$ concentration (250-2,000 mg/L), the amounts of BPA adsorbed by WCP-SM-AC increased till 1,000 mg/L of $P_2O_5$; however, above 1,000 mg/L of $P_2O_5$, the same amounts adsorbed at 1,000 mg/L of $P_2O_5$ were obtained. With increasing reaction temperature, the reaction rate increased, but the adsorbed amounts decreased, especially for the activated carbon before surface modification. The amounts of BPA adsorbed by WCP-AC and WCP-SM-AC were similar in the pH range of 5-9, but significantly decreased at pH 11, and increased with increasing ionic strength due to screening and salting-out effects.

• Fisheries and Aquatic Sciences
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• v.5 no.4
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• pp.251-257
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• 2002

Effects of bisphenol-A (BPA) on vitellogenin (VTG) synthesis and estrogen-estrogen receptor $(E_2- ER)$ binding activity were examined in primary hepatocyte cultures of rainbow trout, Oncorhynchus mykiss. Hepatocytes were precultured for 2 days and then $estradiol-17\beta\;(E_2,\;2\times10^{-6}M)\;BPA\;(10^{-5}-10^{-8}M)$ and/or 4-hydroxy-tamoxifen $(4-OHT,\;10^{-6} M)$ were simultaneously added to the incubation medium. Hepatocytes were cultured for 5 more days and then spent medium was analyzed by SDS-PAGE for VTG production. The addition of BPA to the incubation medium had no effect on the viability of hepatocytes in the culture. On the other hand, BPA increased VTG production in a concentration-dependent way and a significant increment occurred at BPA concentrations greater than $10^{-6}$M. Although VTG was increased by the addition of $E_2\;(2\times10^{-6}\;M)\;or\;BPA\;(10^{-5}M)$, its were reduced by a simultaneous 4-OHT $(10^{-6}\;M)$ addition. BPA inhibited $E_2-human$ ER binding activity by $72\%$ at $10^{-5}$ M of BPA. These results suggested that BPA induced VTG synthesis by BPA-ER binding activity in the hepatocyte of rainbow trout.

• Biomedical Science Letters
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• v.23 no.2
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• pp.128-132
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• 2017

Streptozotocin (STZ), bisphenol A (BPA), and diethylstilbestrol (DES) are known as endocrine disruptors, occurs oxidative stress in animal cells. Generally, oxidative stress induces reactive oxygen species (ROS) and lipid peroxidation of sperm and lead to decreased viability and fertility in pigs. Therefore, we investigated the influence of STZ, BPA and DES on ROS production and lipid peroxidation on boar sperm. Collected sperm were incubated with semen extender containing $10{\mu}M\;STZ$, $10{\mu}M\;BPA$ and $20{\mu}M\;DES$ for 3, 6 and 9 hours. Intracellular ROS and lipid peroxidation of sperm were analyzed by 2', 7'-dichlorofluorescein diacetate and malondialdehyde methods. The results show that, intracellular ROS was not significantly different among the all treatments, but lipid peroxidation was significantly increased in STZ group at 3 hour after incubation with boar sperm (P<0.05). These results suggest that STZ stimulates lipid peroxidation more than ROS production and may exert a negative effect on sperm fertility.

• Molecular & Cellular Toxicology
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• v.4 no.3
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• pp.230-234
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• 2008

Epidemiological studies demonstrate an adverse effect of several environmental and occupational exposures on male sex hormone. Bisphenol A (BPA) is a weak estrogen and a widely used industrial chemical. Epoxy resin painters may be continuously exposed to BPA at high concentrations. The effect of occupational exposure of BPA on male reproduction was examined by measuring the urinary BPA, testosterone and gonadotropic hormones of epoxy resin painters in the shipyard. The painters had significantly higher concentrations of urinary BPA (2.61${\pm}$1.08 ${\mu}g$/g creatinine) than controls (1.38${\pm}$0.5 9 ${\mu}g$/g creatinine). In serum, the testosterone level of painters was significantly decreased but the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels of painters were significantly higher than controls. Occupational exposure to BPA influences testosterone and gonadotropic hormones in male workers.

• Biomedical Science Letters
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• v.10 no.4
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• pp.397-401
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• 2004

We have examined congenital malformation in developing chick embryo caused by endocrine disruptor, bisphenol A (BPA). We injected BPA into the air sac of developing egg on day 4 of incubation. BPA-treated group with a concentration of 10 ㎍/egg showed a little decrease on their body length compared to the untreated group. But the group treated with 50㎍/egg revealed severe malformation in eyeballs and bills. The group treated with 100㎍/egg could not continue their development after few days of incubation. These results indicate that BPA clearly inhibits the normal development in chick and it should be toxic to the developing fetus at early stage and in various tissues. The study should contribute to the understanding of toxic effect of BPA in developing human fetus when exposed to the BPA.