• Archives of Pharmacal Research
• /
• v.26 no.1
• /
• pp.58-63
• /
• 2003

Ginseng has been recommended to alleviate the menopausal symptoms, which indicates that components of ginseng very likely contain estrogenic activity. We have examined the possibility that a component of Panax ginseng, $ginsenoside-R_{b1}$ acts by binding to estrogen receptor. We have investigated the estrogenic activity of $ginsenoside-R_{b1}$ in a transient transfection system using estrogen-responsive luciferase plasmids in MCF-7 cells. $ginsenoside-R_{b1}$ activated the transcription of the estrogen-responsive luciferase reporter gene in MCF-7 breast cancer cells at a concentration of 50 $\mu$M. Activation was inhibited by the specific estrogen receptor antagonist ICI 182,780, indicating that the estrogenic effect of $ginsenoside-R_{b1}$ is estrogen receptor dependent. Next, we evaluated the ability of $ginsenoside-R_{b1}$ to induce the estrogen-responsive gene c-fos by semi-quantitative RT-PCR assays and Western analyses. $ginsenoside-R_{b1}$ increased c-fos both at mRNA and protein levels. However, $ginsenoside-R_{b1}$ failed to activate the glucocorticoid receptor, the retinoic acid receptor, or the androgen receptor in CV-1 cells transiently transfected with the corresponding steroid hormone receptors and hormone responsive reporter plasmids. These data support our hypothesis that $ginsenoside-R_{b1}$ acts a weak phytoestrogen, presumably by binding and activating the estrogen receptor.

• Korean Journal of Animal Reproduction
• /
• v.22 no.1
• /
• pp.81-87
• /
• 1998

This experiment was carried out with 12 Korean native heifers(8~12month old, body weight, 160~240kg) raised at a farm of Chang-Soo Livestock Cooperatives to evaluate the effects of rGH(recombinant growth hormone) on serum concentrations of growth hormone, estrogen, and IGF-I, weight gain, teat volume gain and processing enzyme activity of IGF-I, binding protein III at 28 day intervals. Animals used were injected with 250mg rGH at 14 day intervals from December to Ferbruary in 1994. The significant difference was found in the group of treatment on the 4th week in the endogenous GH(p<.01) and 8th week in estrogen and IGF-I(p<.05) after injectin of rGH in Korean native heifers. There were significant differences between control group and treatment group in weight and teat volume on 8th week after treatment(p<.05). Processing enzyme activity before injection of rGH were low. However, heifers injected with 250mg of rGH showed that processing enzyme activity of IGF binding protein was highly increased throughout the experiment. Present results suggest that injection of exogenous rGH to heifers can increase the growth performance and udder development of Korean native heifers by the endogenous hormonal changes.

• Archives of Pharmacal Research
• /
• v.26 no.1
• /
• pp.53-57
• /
• 2003

We have found that ginsenoside Rc and Re induce c-fos in MCF-7 human breast carcinoma cells at both the mRNA and protein levels. However, neither ginsenoside activated the expression of reporter gene under the control of AP-1/TPA response elements. We have also examined the possibility that ginsenoside Rc and Re act by binding to intracellular steroid hormone receptors that act as transcriptional factors in the nucleus in inducing c-fos mRNA in MCF7 human breast carcinoma cells. However, ginsenoside Rc and Re did not bind to glucocorticoid, androgen, estrogen, or retinoic acid receptors as examined by the transcription activation of the luciferase reporter genes in CV-1 cells that were transiently transfected with the corresponding steroid hormone receptors and hormone responsive luciferase reporter plasmids. These data demonstrate that ginsenoside Rc and Re act via other transcription factors and not via estrogen receptor in c-Fos expression.

• Biomedical Science Letters
• /
• v.24 no.3
• /
• pp.143-149
• /
• 2018

Excessive exposure to estrogens is the most important risk factor for the development of hormone-sensitive cancers, especially breast cancer. Estrogen stimulates the expression of genes and proteins involved in cell proliferation by binding to estrogen receptor (ER). Another possible mechanism of ER-independent carcinogenicity of estrogens is based on the hydroxylation of estradiol resulting in the formation of catechol estrogens. Catechol estrogen 4-hydroxyestradiol ($4-OHE_2$) is further oxidized to catechol estrogen-3,4-quinones, the major carcinogenic metabolites of estrogens. Evidence increasingly supports the critical role of $4-OHE_2$ in hormonal carcinogenesis via DNA adduct formation or production of reactive oxygen species, which finally contribute to the transformation of normal mammary epithelial cells and the enhanced growth of breast cancer cells. It is also reported that the level of $4-OHE_2$ or its quinones is highly up-regulated in urine or tissues of breast cancer patients. Thus, we highlight the oncogenic roles of $4-OHE_2$ in catechol estrogen-induced breast carcinogenesis.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.3
• /
• pp.1507-1512
• /
• 2016

Background: Risk of developing breast cancer increases with short breastfeeding and the use of hormones. The prognosis of breast cancer is better if the tumours are hormone receptor positive. Since breast feeding affects estrogen and progesterone receptors, we wanted to investigate how such reproductive factors as breastfeeding and the use of hormones interact with known prognostic markers and specific tumour characteristics in women with breast cancer. Materials and Methods: A total of 250 women treated for breast cancer from a larger cohort completed a questionnaire on breastfeeding, number and age at births and use of hormones. A logistic regression analysis was made to search for connections between known prognostic markers on the one hand (type of cancer, grade, tumor size, estrogen receptor and progesterone receptor, lymphovascular invasion and DNA-ploidy) and reproductive data, breastfeeding, and hormone use on the other. Results and Conclusions: Hormone use, but not breastfeeding, was significantly associated, also on multivariate analysis, with the prognostic variable lymphovascular invasion, connected to a worse prognosis. No other hormone use or breast feeding correlations with prognostic variables were found.

• Archives of Obesity and Metabolism
• /
• v.2 no.2
• /
• pp.54-63
• /
• 2023

Estrogen is crucial in regulating food intake, energy expenditure, glucose metabolism, and lipid metabolism. During menopause, the decline in estrogen levels predisposes women to weight gain, abdominal obesity, insulin resistance, type 2 diabetes, hypertension, and cardiovascular disease (CVD). Menopausal hormone therapy (MHT) prevents weight gain, improves lipid metabolism by lowering low-density lipoprotein cholesterol while raising high-density lipoprotein cholesterol, and delays the onset of type 2 diabetes in menopausal women. The effect of MHT on CVD in menopausal women remains controversial. The Women's Health Initiative study was terminated prematurely after it revealed that hormone administration increased the risk of myocardial infarction, stroke, and thromboembolism. However, some studies have found that MHT had no effect or decreased the risk of CVD. The inconsistent results were likely due to multiple factors, including the timing of hormone therapy initiation, duration of therapy, type and dosage, and presence or absence of CVD risk factors at the start of treatment. Despite its benefits in terms of managing weight gain and reducing the risk of type 2 diabetes, dyslipidemia, and CVD associated with obesity, it is not recommended as the primary therapy for weight loss or diabetes prevention. MHT is primarily indicated for postmenopausal women, who are likely to benefit from its potential to prevent weight gain and improve lipid metabolism.

• Journal of Korean Medicine Rehabilitation
• /
• v.30 no.1
• /
• pp.1-12
• /
• 2020

Objectives Depletion of ovarian function after menopause in women induces estrogen deficiency leading to increased fat and decreased muscle mass. In this study, we examined the effect of herbal medicines by measuring hormone expression in muscle tissue of estrogen-deficient rats induced by ovariectomy. Methods Ovariectomy was performed to induce estrogen deficiency, and mice were given herbal prescription (HP) for 6 weeks. Estrogen-deficient rats were divided into two groups: one group (HPH) which were orally administered HP 200 mg/kg and the other group (HPL) administered HP 40 mg/kg. Weight changes in both groups were measured using polymerase chain reaction (PCR). After extraction of the femoral muscles in mice, the expression of the leptin, lipoprotein lipase (LPL), diacyl glycerol acyltransferase (DGAT)1, peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α, NADH dehydrogenase (NDH), farnesyl diphosphate farnesyltransferase (FDFT)1, lanosterol synthase (LSS), phosphatidylethanolamine N-methyltransferase (PEMT), and peroxiredoxin (Prdx6) were measured using PCR. Results HP increased the expression of leptin, LPL, DGAT1, PGC-1α, NDH, FDFT1, LSS, PEMT, and Prdx6. HP affects body fat metabolism and is effective in improving menopausal obesity and obesity complications caused by estrogen deficiency. However, HP does not affect the expression of tumor necrosis factor-α and 3-hydroxy-3-methylglutaryl-CoA reductase, and thus will not be effective in obesity-related metabolic diseases. Conclusions HP is thought to inhibit weight gain by regulating hormone expression related to glucose metabolism and lipid metabolism in muscle tissue of estrogen-deficient rats.

• BMB Reports
• /
• v.44 no.10
• /
• pp.613-618
• /
• 2011

Two key molecules in skeletal tissues are bone formation master transcription factor Runx2 and the steroid hormone estrogen. It is well known that these two molecules play pivotal roles in bone homeostasis; however, the functional interaction between Runx2 and estrogen synthesis in skeletal tissues is largely unknown. Recent studies have indicated that there is a positive relationship between Runx2 and the estrogen biosynthesis pathway. In this review, a possible functional link between Runx2 and estrogen synthesis pathway in skeletal tissues will be discusses as well as the biological significance of this interaction.

• The Korean Journal of Physiology and Pharmacology
• /
• v.17 no.5
• /
• pp.423-426
• /
• 2013

Females are more often affected by constipation than males, especially during pregnancy, which is related to the menstrual cycle. Although still controversial, alterations of progesterone and estrogen may be responsible. Therefore, this study was conducted in order to determine whether the female sex steroid hormone itself is responsible for development of constipation in both female and male mice. Administration of estrogen resulted in a decrease in weight of accumulated feces on days 2, 3, 4, and 5 in male mice and on day 5 in female mice, compared with the control group, but progesterone administration did not. Administration of estrogen resulted in a decrease in gastrointestinal movement, compared to normal; however, no significant change was observed by administration of progesterone. In conclusion, estrogen, rather than progesterone, may be a detrimental factor of constipation via decreased bowel movement in mice.

• Environmental Mutagens and Carcinogens
• /
• v.22 no.3
• /
• pp.175-182
• /
• 2002

Endocrine disruptors (EDs) are the chemicals that affect endocrine systems through activation or inhibition of steroid hormone response. It is necessary to have a good system to evaluate rapidly and accurately endocrine-disrupting activities of suspected chemicals and their degradation products. The key targets of EDs are nuclear hormone receptors, which bind to steroid hormones and regulate their gene transcription. We constructed a co-expression system of Gal4p DNA binding domain (DBD)- ligand binding domain of human estrogen receptor $\alpha$ or $\beta$, and Gal4p transactivation domain (TAD)-co-activator AIB-1, SRC-1 or TIF-2 in Saccharomyces cerevisiae with a chromosome-integrated lacZ reporter gene under the control of CYC1 promoter and Gal4p binding site (GAL4 upstream activating sequence, GAL4$_{UAS}$). Expression of this reporter gene was dependent on the presence of estrogen or EDs in the culture medium. We found that the two-hybrid system with combination of the hER$\beta$ LBD and co-activator SRC-1 was most effective in the xenoestrogen-dependent induction of reporter activity. The extent of transcriptional activation by those chemicals correlated with their estrogenic activities measured by other assay systems, indicating that this assay system is efficient and reliable for measuring estrogenic activity. The data in this research demonstrated that the yeast detection system using steroid hormone receptor and co-activator is a useful tool for identifying chemicals that interact with steroid receptors.s.