• Environmental Analysis Health and Toxicology
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• v.31
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• pp.10.1-10.8
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• 2016

Objectives Aromatase inhibitors that block estrogen synthesis are a proven first-line hormonal therapy for postmenopausal breast cancer. Although it is known that standardized extract of Ginkgo biloba (EGb761) induces anti-carcinogenic effects like the aromatase inhibitors, the effects of EGb761 on steroidogenesis have not been studied yet. Therefore, the effects of EGb761 on steroidogenesis and aromatase activity was studied using a H295R cell model, which was a good in vitro model to predict effects on human adrenal steroidogenesis. Methods Cortisol, aldosterone, testosterone, and $17{\beta}$-estradiol were evaluated in the H295R cells by competitive enzyme-linked immunospecific assay after exposure to EGb761. Real-time polymerase chain reaction were performed to evaluate effects on critical genes in steroid hormone production, specifically cytochrome P450 (CYP11/ 17/19/21) and the hydroxysteroid dehydrogenases ($3{\beta}$-HSD2 and $17{\beta}$-HSD1/4). Finally, aromatase activities were measured with a tritiated water-release assay and by western blotting analysis. Results H295R cells exposed to EGb761 (10 and $100{\mu}g/mL$) showed a significant decrease in $17{\beta}$-estradiol and testosterone, but no change in aldosterone or cortisol. Genes (CYP19 and $17{\beta}$-HSD1) related to the estrogen steroidogenesis were significantly decreased by EGb761. EGb761 treatment of H295R cells resulted in a significant decrease of aromatase activity as measured by the direct and indirect assays. The coding sequence/Exon PII of CYP19 gene transcript and protein level of CYP19 were significantly decreased by EGb761. Conclusions These results suggest that EGb761 could regulate steroidogenesis-related genes such as CYP19 and $17{\beta}$-HSD1, and lead to a decrease in $17{\beta}$-estradiol and testosterone. The present study provides good information on potential therapeutic effects of EGb761 on estrogen dependent breast cancer.

• Clinical and Experimental Reproductive Medicine
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• v.14 no.1
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• pp.61-70
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• 1987

This study was carried out to investigate the effects of the antiestrogens, LY-117018 and tamoxifen on reproductive organ of ovariectomized immature rats and also to elucidate the mechanism of action of said compounds by bioassay. Each of LY-117018, tamoxifen and estradiol-17${\beta}$ was administered to ovariectomized immature rats at various dose levels. Forty hours after drug administration, tested rats were sacrificed and uterine wet weight, DNA and RNA contents in uterine and liver tissues were investigated. At the same time, uterine wet weight was also investigated with some other rats treated with 125${\mu}g$ of LY-117018 together with increasing doses of tamoxifen. Ovariectomized immature rats given 25${\mu}g$ single dose of each drug were sacrificed on Day 1, 2, 3, 4, and 5 after drug administration and uterine was weighed to estimate the duration of action of LY-117018 and tamoxifen. The results were summarized as follows: 1. The administration of LY-117018 or tamoxifen to ovariectomized rats increased uterine wet weight and DNA and RNA contents in uterine tissues with more increase in tamoxifen groups, but significant differences between groups treated at dose levels of 5${\beta}$ or more of both drugs were observed. Estradiol-17${\beta}$ groups showed significant increases in each group(P<0.01). 2. The administration of LY-117018 or tamoxifen to each group significantly increased DNA and RNA contents in liver tissues with more increase in tamoxifen groups. Estradiol-17${\beta}$ groups showed no significant differences between treatment groups of 5${\beta}$ or more. 3. Treatment with 125${\beta}$ of LY-117018 together with various doses of tamoxifen resulted in more increase of uterine wet weight than treatment with a single dose of LY-117018 or tamoxifen. 4. Treatment with 0.2${\beta}$ of LY-117018 or tamoxifen in ovariectomized rats decreased uterine wet weight,DNA and RNA contents in liver and uterine tissues compared with ovariectomized control. 5. The duration of effective action of LY-1l7018 and tamoxifen was 4 days or more. 6. There was significant difference(P<0.001) in uterine wet weight between Day 9after ovariectomy (two days after LY-117018 or tamoxifen treatment) and Day 10(63.7${\pm}$3.5mg, 39.2${\pm}$9.9mg, respectively).

• Journal of Food Hygiene and Safety
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• v.22 no.3
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• pp.209-212
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• 2007

To evaluate the estrogenic activities of di-ethyl hexyl phthalate (DEHP) and di-butyl phthalate (DBP), two phthalates known as endocrine disrupters, we used MCF-7 human breast cancer cell line. As results, DBP and DEHP had estrogenic effects. In brief, the concentration of maximal MCF-7 cell proliferation was $10^{-7}M\;and\;10^{-8}M$ for DEHP and DBP, respectively. The ratio of maximal cell yield of the test compounds to that of $17{\beta}-estradiol$ was 87.5% for DEHP and 73.4% for DBP. In summary, both DEHP and DBP had cell proliferation potencies in the MCF-7 cell. Potencies ranged from approximately 10 to 100 times less than 17beta-estradiol. DBP was stronger than DEHP in the concentration of maximal efficacy. However, DEHP was stronger than DBP in the MCF-7 cell proliferation. Results from this study suggested that DEHP and DBP may play an important role in the estrogenic activity. Therefore, it is suggested that DEHP and DBP are estrogenic.

• Korean Journal of Ichthyology
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• v.12 no.3
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• pp.173-179
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• 2000

Effects of Estradiol-$17\beta(E_2)$ and 2, 4-dichlorophenoxy acetic acid (2, 4-D) on vitellogenin(VTG) production were investigated in primary hepatocyte culture of olive flounder, Paralichthys olivaceus. Highest survival rate of hepatocyte were observed at $27^{\circ}C$, which markedly declined equal to 50% of those of $15^{\circ}C$. Vitellogenin production peaked at the concentration of $10^{-6}M\;E_2$. No effect was observed on VTG production at various concentrations of 2, 4-D. However, a low concentration of 2, 4-D (ie, $10^{-8}M$) only appeared increased VTG production. $E_2$ or $10^{-8}M$ 2, 4-D-primed VTG production was markedly inhibited by the addition of $10^{-6}M$ tamoxifen to the culture medium(P<0.01). Inhibition was not affected by combinational treatment with $10^{-6}M$ $E_2$ and $10^{-6}M$ 2, 4-D. These results from the current investigation suggest that 2, 4-D mimics $E_2$, but the mechanism of reaction in inducing the $E_2$ receptor are different in VTG production in oliver flounder hepatocytes.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2002.11a
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• pp.141-144
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• 2002

Environmental estrogens are natural or synthetic substances present in the aquatic environment, especially in effluent from sewage treatment. However, the adverse effects of these estrogenic substances on fish reproduction are unknown. Di-2-ethylhexyl phthalate (DEHP) is the most common phthalate, which Ps used as a plasticizer in polyvinylchloride (PVC), and it is widespread in the environment and has been found in aquatic organisms and sediments. Therefore, juvenile common carps (Cyprinus carpio) were exposed to nominal concentrations of 17$\beta$-estradiol (E2) (0.5, 5, 50 $\mu\textrm{g}$/L) and DEHP (10, 100, 500 $\mu\textrm{g}$/L) for 21 days, to determine the adverse reproductive effects of these compounds on plasma vitellogenin (VTG) induction, sex steroid level, and gonad weight. Electrophoresis (SDS-PAGE) revealed that much of VTG was induced in fish exposed to 5 and 50 E$_2$ $\mu\textrm{g}$/L, but none of DEHP exposure showed induction. Enzyme-linked immunosorbent assay (ELISA) revealed that VTG was significantly induced in fish exposed to 5 and 50 E$_2$ $\mu\textrm{g}$/L, and combination of 50 E$_2$ $\mu\textrm{g}$/L with 10 and 500 DEHP $\mu\textrm{g}$/L, but none of DEHP exposure showed induction. Analysis of sex steroid levels in some fish revealed that testosterone (T) was detected in both male and female fish of the control and DEHP exposures, but none of fish exposed to 22 concentrations had detectable testosterone level. On the other hand, E$_2$ exposure induced 17$\beta$-estradiol in plasma of male fish, but there was no induction of 17$\beta$-estradiol in plasma of male fish exposed to DEHP. Comparison of gonadosomatic index (GSI) revealed that maximal E$_2$ exposure inhibited ovarian growth, but maximal DEHP exposure stimulated testicular growth. The results indicated that those comparisons can be a useful bio-indicator for determining adverse reproductive effect of endocrine disrupting chemicals (EDCs).

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.70-74
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• 1985

Serum levels of LH, FSH, prolactin, estradiol-$17{\beta}$ and progesterone were investigated every 20 days after the day of mating for the period of 140 days, at the day of parturition and thereafter 10 th and 20th day postpartum in Korean native goats. Serum levels of LH were highest with 1.95 mIU/ml at the 60 days after gestation, but maintained high levels until 100 days after gestation, and thereafter decreased gradually to 0.02 mIU/ml at the day of parturition. Prolactin concentrations increased from the 140 days after gestation, and showed highest levels with 29.75 ng/ml at the day of parturition, then decreased gradually. FSH levels determined were below 1.25 mIU/ml during the experimental period. Estradiol-$17{\beta}$ concentrations increased gradually from 7.51 pg/ml at the 20 days after gestation to 159.62 pg/ml at the day of parturition, and decreased rapidly after parturition. Progesterone levels were highest with 6.62 ng/ml at the 120 days after gestation, the decreased rapidly to 1.25 ng/ml at the day of parturition.

• Journal of Embryo Transfer
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• v.28 no.4
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• pp.315-318
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• 2013

This study was conducted to investigate the changes of hormone levels of serum progesterone (P4) and estradiol-$17{\beta}$ (E2) in sows of Landrace (L), Yorkshire (Y) and F1 (L ${\times}$ Y) (respectively n=3) with excellent ability, and to provide a baseline data for improving reproductive performance. In this experiment, the sows at the age of 12 months or more were used. The sows were fed by two way methods, one is conventional methods and the other is 3 days-flushing feed before estrus. Each pig's blood was collected in 3, 6, 9, 12, 15 and 18 days after the estrus for the analyses of P4 and E2. Serum was separated by centrifugation for 15 min. with 3,000 rpm. Progesterone and estradiol-$17{\beta}$ were measured by immunochemical assay (ELIZA test). In conventional feeding, serum progesterone levels were significantly (p<0.01) higher in F1 than in L and Y. No significant differences in P4 concentrations were seen between the L and Y of sows. Serum E2 levels were similar the serum progesterone levels. In the case of flushing feed, the tendency of hormonal changes were similar to conventional methods. But almost of hormonal levels were a little higher than that of conventional methods. P4 level of L and Y in flushing feed were significantly different (p<0.01). Serum E2 level of Y in flushing feed was significantly different among the breeds (p<0.01). These results were similar to the tendency of hormonal changes in general sows and moreover, flushing feed is known to develop the swine production, these results proved the fact of the methods. And these results suggested that more studies about hormonal changes in sows according to seasonal and nutritional factors should be needed.

• Development and Reproduction
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• v.8 no.2
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• pp.99-111
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• 2004

The present study aimed to investigate whether the expression of ADAM-8, 9, 10, 12, 15, 17 and ADAMTS-1 genes is controlled by ovarian steroid hormones. Ovariectomized mice were injected with 17 ${\beta}$-estradiol ($E_2$), progesterone ($P_4$, or $E_2+P_4$. Uterine tissues were processed for RT-PCR and immunoblotting. The results of RT-PCR showed that administration of $E_2$ increases the level of ADAM-8, 12 and ADAM17 expression compared to $P_4$ or control group. In contrast, administration of $P_4$ markedly stimulated the expression of ADAM-9, 10, 15 and ADAMTS-1, whereas $E_2$ did not. Immunoblotting analysis using anti-mouse ADAM polyclonal antibodies demonstrated that $E_2$ alone or $E_2+P_4$ treatment results in the strong expression of ADAM-8, 12 and ADAM17 proteins but $P_4$ alone or control group gave weak expression. In contrast, $P_4$ alone or $E_2$ plus $P_4$ treatment increased the expression level of ADAM-9, 10, 15 and DAMTS-1 proteins. $E_2$ alone or control group did not increase the expression. These results indicate that expression of ADAM-8, 12 and ADAM17 genes is upregulated by $E_2$ and that of ADAM-9, 10, 15 and ADAMTS-1 gene is upregulated by $P_4$.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.5
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• pp.682-688
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• 1999

Thirty nine pregnant Javanese thin-tail ewes (20 and 19 carried a single and multiple [2 to 3] fetuses, respectively), and six nonpregnant ewes as controls were used to measure maternal serum hormone and blood metabolite concentrations as predictors of number of fetuses carried during pregnancy. Serum hormones (progesterone, estradiol, triiodothyronine, and cortisol) and blood metabolites (b-hydroxy butyric acid [BHBA], and blood urea nitrogen [BUN]) were determined every four weeks during pregnancy and were used to predict litter size by discriminant analysis. The results of data analysis indicated that serum progesterone and estradiol concentrations at weeks 8, 12, 16 of pregnancy could be used to predict the number of fetuses carried with precision of 86.7 to 95.6%. Serum triiodothyronine, cortisol, BHBA, and BUN concentrations during pregnancy, however, were not good predictors of the number of fetuses carried. Serum progesterone and estradiol concentrations as early as 8 weeks of pregnancy in sheep could predict the number of fetuses carried with 86.7% precision.

• Korean Journal of Animal Reproduction
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• v.16 no.3
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• pp.231-237
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• 1992

The effects to the corticosteroid dexamethasone(DEX) and(or) estradiol-benzoate(E-B) treated to induction of parturition and birth weights of the young was conducted in 48 pregnant Korean native goats. The animals were divided into 4 goats per each treatment by the time(142, 145 and 148 day of pregnancy) and dosage(DEX 15, 20mg, DEX 8mg＋E-B 10mg and DEX 13mg＋E-B 7.5mg per goat). The results obtained were summarized as follows: 1 The time for induction of parturtion after DEX(15, 20mg) treatment on day 148 of pregnancy was significantly(P<0.01) shorter than 142 and 145 days. There was no significant difference each dosage of DEX on same day of pregnancy. 2. The addition of E-B to DEX treatment compared with DEX alone group at day 142 and 145 of pregnancy were significantly(P<0.01) shorter the time for induction of parturition. However, treatment with DEX along or with E-B on 148 day of pregnancy did not affect the time to induction(about 27 hrs) of parturition between each treatment. 3. The birth weight of kids after parturition was heaviest(P<0.01) on day 148 of pregnancy. However, development and vigor of kids were not significant different between DEX alone treatment and with E-B.