• Journal of Microbiology and Biotechnology
• /
• v.10 no.3
• /
• pp.293-299
• /
• 2000

Many methods have been developed for screening chemicals with hormonal activity. Using recombinant yeasts expressing either human estrogen receptor [Saccharomyces cerevisiae ER + LYS 8127 (YER)] or androgen receptor [S. cerevisiae AR + 8320 (YAR)], we evaluated the hormonal activities of several chemicals by induction of ${\beta}-galactosidase$ activity. The chemicals were $17{\beta}-estradiol$ (E2), testosterone (T), ${\rho}-nonylphenol$ (NP), bisphenol A (BPA), genistein (GEN), 2-bromopropane (2-BP), dibutyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and butylparaben (BP). To assess the estrogenicity of NP, the result of the in vitro recombinant yeast assay was compared with an E-screen assay using MCF-7 human breast cancer cells and an uterotrophid assay using ovariectomized mice. In the YER yeast cells, E2, NP, BPA, GEN, and BP exhibited estrogenicity in a doseresponse manner, while TCDD did not. All the chemicals tested, except T, did not show androgenicity in the YAR yeast cell. The sensitivity of the yeast (YER) assay system to the estrogenic effect of NP was similar to that of the E-screen assay. NP was also estrogenic in the uterotrophic assay. However, in terms of convenience and costs, the yeast assay was superior to the E-screen assay or uterotrophic assay. These results suggest that the recombinant yeast assay can be used as a rapid tool for detecting chemicals with hormonal activities.

• Nano
• /
• v.13 no.11
• /
• pp.1850127.1-1850127.13
• /
• 2018

Bi metal deposited on $Bi_2MoO_6$ composite photocatalysts have been successfully synthesized via a simple reduction method at room temperature with using $NaBH_4$ as the reducing agent. The photocatalytic activity of the composite was evaluated by degradation of rhodamine B (RhB) and bisphenol A (BPA) solution under visible light. The rate constant of $Bi/Bi_2MoO_6$ composite to RhB is 10.8 times that of $Bi_2MoO_6$, and the degradation rate constant of BPA is 6.9 times of that of $Bi_2MoO_6$. Nitrogen absorption-desorption isotherm proved that the increase of specific surface area is one of the reasons for the improvement of photocatalytic degradation activity of $Bi/Bi_2MoO_6$ composites. The higher charge transfer efficiency of $Bi/Bi_2MoO_6$ is found through the characterization of the photocurrent and impedance, which are attributed to the surface plasmon resonance (SPR) effect produced by the introduction of the metal Bi monomer in the composite. Free radical capture experiments proved that cavitation is the main active species. Based on the above conclusions, a possible mechanism of photocatalytic degradation is proposed.

• Korean Chemical Engineering Research
• /
• v.50 no.5
• /
• pp.766-771
• /
• 2012

PC (polycarbonate) is one of the widely used engineering plastics. Polycarbonate (PC) is traditionally produced by the reaction of phosgene and bisphenol-A. This phosgene process has the disadvantage as the high toxicity and corrosiveness of phosgene. The main point of focus to overcome the disadvantage of phosgene based process has been a route through dimethyl carbonate (DMC) to diphenyl carbonate (DPC). In this paper, for the DPC synthesis reaction using PBO as a catalyst, the effect of reaction temperature, reactant ratio, catalyst concentration on the reaction yield was investigated. A kinetic model for the DPC synthesis reaction was proposed and kinetic parameters for the proposed model was determined from batch reactor experiments. The predicted results by the proposed model were in good agreement with the experimental results.

• Membrane Journal
• /
• v.15 no.4
• /
• pp.297-309
• /
• 2005

As a number of potential endocrine disrupting compounds (EDCs) are released into the environment, recently growing attention has been drawn to them. Therefore sensitive and reliable analytical methods are essential to monitor those compounds. In this study, complementary CC-MS and LC-MS were employed to analyze the endocrine disrupters, and the results of two methods were compared for di(2-ethylhexyl)phthalate (DEHP), benzylbutylphthalate (BBP), pentachlorophenol (PCP), and 4,4'-Isopropylidenediphenol (Bisphenol-A, or BPA). The results indicate that it was possible to lower the detection limits of EDCs by LC-MS. Also, LC-MS enabled to identify the EDCs as almost intact molecules. Furthermore, this study presented a nanofiltration membrane (MWCO 250) and a ultrafiltration membrane (MWCO 1,000) filtration system as methods far removing EDCs from drinking water containing $\gamma$-BHC, p,p'-DDE, BBP, p,p'-DDT, DEHP, PCP, and BPA. Cross-flow type nanofiltrations showed $100\%$ removal of EDCs, and the result implies that MWCO 250 nanofilter was sufficient for treatment of EDCs. The ratio of permeate flux to mass transfer coefficient of nanofiltration, high flux ultrafiltration, and low flux ultrafiltration with ultrapure water were 0.67, 3.4, and 0.44, respectively. It was found that nanofiltration and low flux ultrafiltration were operated at a diffusion dominant condition, and the high flux ultrafiltration was operated at a convection dominant condition. Furthermore, a diffusion dominant process attained reasonable rejection of EDCs. The removal in the ultrafiltration was depending on the molecular weight of an EDC, and the filtration was governed by diffusion-dominant hydrodynamic conditions.

• Korean Journal of Pharmacognosy
• /
• v.47 no.3
• /
• pp.264-272
• /
• 2016

This study was carried out to evaluate the preventive effect of the Corni Fructus (SSU) 50 % EtOH extract (SSU-E50) against bisphenol A (BPA) toxicity in Leydig cells and improving testosterone deficiency syndrome in orchidectomized Sprague-Dawly (SD) rats. Antioxidant properties were measured by radical scavenging activity of SSU-E50 in ABTS assay and DPPH assay. Also, real-time polymerase chain reaction(real-time PCR) was performed to quantify the mRNA expression levels of antioxidant enzyme. SD rats were divided into eight group: normal, sham operation (Sham), orchidectomized (ORX), ORX treated with testosterone 1 mg/kg (Tes. 1), ORX treated with SSU water extract 100 mg/kg (SSU-A 100) and 300 mg/kg (SSU-A 300), ORX treated with SSU 50 % EtOH extract 100 mg/kg (SSU-E 100) and 300 mg/kg (SSU-E 300). On a comparative basis, the SSU showed better activity quenching ABTS with an IC50 value of 0.29 mg/ml and DPPH with an IC50 value of 0.33 mg/ml. Cell viability was evaluated by MTS assay as described not cytotoxic at the highest concentration of $500{\mu}g/ml$. Cytotoxicity of BPA showed in $200{\mu}M$, but definitely survived by treatment with SSU in Leydig cells. In addition, SSU increased the mRNA expression levels of antioxidant enzyme in BPA induced Leydig cells. Superoxide dismutase (SOD) level was slightly increased and malondialdehyde (MDA) level was decreased with SSU-A 100 in in-vivo. These results suggest that Corni Fructus extracts have the greatest property as a natural anti-oxidative and improves testosterone deficiency syndrome source.

• Journal of Food Hygiene and Safety
• /
• v.21 no.2
• /
• pp.100-106
• /
• 2006

The use of underarm and body care cosmetics with oestrogenic chemical excipients (particularly the parabens) and the hypothesized association with breast cancer incidence, particularly in women. It is noted that the type of cosmetic product is irrelevant (e.g. antiperspirant/deodorant versus body lotion, moisturizers or sprays versus creams) and attention must focus on issues of actual exposure to chemicals through continued dermal application of body care products and the endocrine/hormonal activity and toxicity of the chemicals in the formulations. To evaluate the estrogenic activities of parabens such as ethylparaben, butylparaben, propylparaben, isobutylparaben and isopropylparaben, we used recombinant yeasts containing the human estrogen receptor [Saccharomyces cerevisiae ER+LYS 8127], human breast cancer MCF-7 cell lines and human estrogen receptor ${\alpha}\;and\;{\beta}$. In E-screen assays, isopropylparaben is the most estrogenic paraben, and in ER competition assay, isobutylparaben is the most estrogenic paraben. We evaluated isopropylparaben was most active in the recombinant yeast assay, followed by propylparaben, ethylparaben, isobutylparaben and butylparaben. Results from this study demonstrate that parabens are observed in human endocrine system. Therefore, we have shown that the parabens is induced the estrogenic activities similar to $17{\beta}$-estradiol and Bisphenol-A.

• Journal of Korean Society of Environmental Engineers
• /
• v.32 no.9
• /
• pp.900-904
• /
• 2010

Polyvinyl chloride (PVC) hoses, polyethylene hose and silicone hose for tap water were tested with respect to migration of phenolic compounds to water. The highest concentrations (0.36~1.97 mg/L) of total phenolic compounds were observed in the test water from PVC hoses. Increasing residual Cl concentration from 0 to 0.5 mg/L or increasing water temperature from 4 to $25^{\circ}C$ increased 3~3.2 times and 100~104 times for migrated total phenolic compounds concentrations, in respectively. A major migrating phenolic compounds from PVC hoses were bisphenol-a (BPA) and it was observed that the concentration of migrating phenolic compounds in the order: DEHP > 2-chlorophenol > 2,4,6-trichlorophenol > 2,4-dichlorophenol from PVC hoses.

• Environmental Mutagens and Carcinogens
• /
• v.24 no.1
• /
• pp.40-45
• /
• 2004

In order to understand the mechanism of the regulation of drug metabolizing enzyme gene expression, we have studied the induction of CYP1A1 and GSTα, μ, π enzymes in Japanese monkey and rhesus monkey after the treatment with 3-methylcholanthrene (3MC) and di-n- butyl phthalate (DBP) and bisphenol A (BPA). The levels of mRNA were measured_by RT-PCR in brain, intestine and liver. In the case of adult monkey, treatment with 3MC induced CYP1A1 mRNA in brain by 2-fold. The treatment with DBP induced CYP1A1 mRNA. Effects of 3MC and DBP on GST mRNA expression was not clear. But GSTμ was slightly inhibited by the treatment with 3MC and DBP. GSTα was not induced by the treatment with 3MC and DBP in brain. GSTπ was slightly induced by the treatment with 3MC and DBP in brain. In the case of fetus monkey, the basal levels of fetus CYP1A1 mRNA and GSTs mRNA were relatively low compared to adult monkey. As the age of monkey increased, the basal levels of CYP1A1 mRNA were also increased. 3MC induced the expression of CYP1A1 mRNA in liver, whereas it didn't significantly induce CYP1A1 mRNA in brain. The levels of GSTμ and GSTα were not changed by the treatment with 3MC and DBP. GSTπ was slightly induced by the treatment with 3MC and DBP.

• Environmental Mutagens and Carcinogens
• /
• v.24 no.1
• /
• pp.19-24
• /
• 2004

In order to understand the mechanism of the regulation of drug metabolizing enzyme gene expression, we have studied the induction of CYP1A1 and $GST\alpha,$ $\mu,$ $\pi$ enzymes in Japanese monkey and rhesus monkey after the treatment with 3-methylcholanthrene (3MC) and di-n-butyl phthalate (DBP) and bisphenol A (BPA). The levels of mRNA were measured by RT-PCR in brain, intestine and liver. In the case of adult monkey, treatment with 3MC induced CYP1A1 mRNA in intestine by 11-fold. The treatment with DBP induced CYP1A1 mRNA. Effects of 3MC and DBP on GST mRNA expression was not clear. But $GST\mu$ was slightly inhibited by the treatment with 3MC and DBP. $GST\alpha$ was induced in intestine by 1.5-fold. $GST\pi$ was slightly induced by the treatment with 3MC and DBP in intestine. In the case of fetus monkey, the basal levels of fetus CYP1A1 mRNA and GSTs mRNA were relatively low compared to adult monkey. As the age of monkey increased, the basal levels of CYP1A1 mRNA were also increased. 3MC induced the expression of CYP1A1 mRNA didn't significantly induce CYP1A1 mRNA in intestine. The levels of $GST\mu$ and $GST\pi$ were not changed by the treatment with 3MC and DBP. $GST\pi$ was slightly induced by the treatment with 3MC and DBP.

• Environmental Mutagens and Carcinogens
• /
• v.24 no.2
• /
• pp.73-78
• /
• 2004

In order to understand the mechanism of the regulation of drug metabolizing enzyme gene expression, we have studied the induction of CYP1A1 and GST$\alpha$, $\mu$, $\pi$ enzymes in Japanese monkey and rhesus monkey after the treatment with 3-methylcholanthrene (3MC) and di-n- butyl phthalate (DBP) and bisphenol A (BPA). The levels of mRNA were measured by RT-PCR in brain, intestine and liver. In the case of adult monkey, treatment with 3MC induced CYP1A1 mRNA in liver by 10-fold. The treatment with DBP induced CYP1A1 mRNA. Effects of 3MC and DBP on GST mRNA expression was not clear. But GST$\mu$ was slightly inhibited by the treatment with 3MC and DBP. GST$\pi$ was not induced by the treatment with 3MC and DBP in liver. GST$\alpha$ was slightly induced by the treatment with 3MC and DBP in liver. In the case of fetus monkey, the basal levels of fetus CYP1A1 mRNA and GSTs mRNA were relatively low compared to adult monkey. As the age of monkey increased, the basal levels of CYP1A1 mRNA were also increased. 3MC induced the expression of CYP1A1 mRNA in liver. The levels of GST$\mu$ and GST$\alpha$ were not changed by the treatment with 3MC and DBP. GST$\pi$ was slightly induced by the treatment with 3MC and DBP.