Histological investigation of the effect of soybean (Glycine max) extracts on the collagen layer and estrogen receptors in the skin of female rats

OBJECTIVES: The purpose of this study was to analyze the effects of soybean extracts obtained using different extraction methods on the skin of female rats. METHOD: A total of 64 female Sprague-Dawley rats were divided into 8 equal groups. Various extracts were administered to the female rats by oral gavage for one month. The groups comprised carboxymethyl cellulose-free control, carboxymethyl cellulose-plus control, 100-mg/kg n-hexane extract, 200-mg/kg n-hexane extract, 100-mg/kg ethyl acetate extract, 200-mg/kg ethyl acetate extract, 100-mg/kg ethanol extract and 200-mg/kg ethanol extract groups. The thickness of the collagen layer and the number of estrogen receptor-positive cells were evaluated. RESULTS: All the extract-treated groups showed a statistically significant decrease in the number of estrogen receptor-positive cells compared with the control groups. Regarding the thickness of the collagen layer, only the 200-mg/kg ethyl acetate extract-treated group showed a significant increase compared with the control groups (p<0.05). CONCLUSIONS: Our data suggest that oral intake of three different total soybean extracts might have positive estrogenic effects on the skin and that only a high-dose ethyl acetate extract can increase the expression of collagen, which may prove to be beneficial for postmenopausal facial skin. ...

Effects of 17-α ethynyl estradiol on proliferation, differentiation & mineralization of osteoprecursor cells.

Background & objectives: The steroidal estrogen 17α-ethynyl estradiol (EE) is an orally bio-active estrogen used in almost all modern formulations of estrogen-progestin combination preparations of oral contraceptives. Contrasting effects of treatment with combined oral contraceptives on bone mineral density of pre-, peri-, and post-menopausal women have been reported, and it has been suggested that the estrogen dose and the type of progestogen may be the main contributing factors for these contrasting results. The objective of this study was to evaluate the effects of EE on osteoprecursor cells. Methods: The effects of single component of oral contraceptive, EE, were tested to see the relationship between EE and osteoblast proliferation, differentiation and mineralization. Tests used included a cell viability test, alkaline phosphatase (ALP) test, alizarin red-S staining, and a Western blot analysis. The effect on cell viability was determined by MTT assay. Differentiation and mineralization were examined using an ALP test and alizarin red-S staining. Protein expressions related to bone formation, such as estrogen receptor-alpha (ER-α), estrogen receptor-beta (ER-β), bone morphogenetic protein-2 (BMP-2), osteocalcin (OCN), and osteopontin (OPN) were evaluated by using a Western blot analysis. Results: Cultures growing in the absence of EE presented the lowest value for the MTT value. However, there were no significant changes in viability/proliferation when EE was added in the medium. Cultures growing in the absence of EE presented the highest value for the ALP activity, and the additional presence of EE resulted in dose-dependent decrease concerning ALP activity. Interpretation & conclusions: Our finding showed that EE in tested dosage within MC3T3-E1 cells seem to affect the proliferation and differentiation; however, significant differences are achieved in ALP activity in early differentiation phase and further studies are needed to elucidate the mechanisms of EE on bone.

Isoflavonas de soya y salud humana: cáncer de mama y sincronización de la pubertad / Soy isoflavones and human health: breast cancer and puberty timing

Background: Accumulated exposure to high levels of estrogen is associated with an increased incidence of breast cancer. Thus, factors such as early puberty, late menopause and hormone replacement therapy are considered to be risk factors, whereas early childbirth, breastfeeding and puberty at a later age are known to consistently decrease the lifetime breast cancer risk. Epidemiological studies suggest that consumption of isoflavones correlates with a lower incidence of breast cancer. Data from human intervention studies show that the effects of isoflavones on early breast cancer markers differ between pre- and post-menopausal women. The reports from experimental animals (rats and mice) on mammary tumors are variable. These results taken together with heterogeneous outcomes of human interventions, have led to a controversy surrounding the intake of isoflavones to reduce breast cancer risk. This review summarizes recent studies and analyzes factors that could explain the variability of results. In mammary tissue, from the cellular endocrine viewpoint, we analyze the effect of isoflavones on the estrogen receptor and their capacity to act as agonists or antagonists. On the issue of puberty timing, we analyze the mechanisms by which girls, but not boys, with higher prepuberal isoflavone intakes appear to enter puberty at a later age.

Tamoxifen use and gallstone formation in postmenopausal breast cancer patients in south Indian population.

BACKGROUND: Tamoxifen is being used in patients with estrogen receptor positive breast cancer as an adjuvant or palliative hormonal therapy. w0 estern studies have found a 30% incidence of gallstones in patients who are taking Tamoxifen and they have proved a significant association between the two. OBJECTIVES : The objective of the study was to find out the association of Tamoxifen use and gallstone formation in postmenopausal breast cancer patients in a South Indian population. METHODS: Ninety patients who had undergone surgery for invasive breast cancer in our institute, and were receiving adjuvant Tamoxifen, were recruited for the study. An equal number of age-matched postmenopausal women were taken as controls. All of them underwent an abdominal ultrasound screening test for gallstones. Presence or absence of gallstones was noted down from their ultrasound scan reports. Pretreatment status of the gall bladder was assessed from the preoperative scan reports. RESULTS: An odds ratio of 1 was derived when the case group was compared with the control group. CONCLUSIONS: In our study we could not establish that an association existed between Tamoxifen use and gallstone formation in postmenopausal South Indian women.

Effect of mifepristone on steroid receptor expression and biotransformation of oestrogen and progesterone in rat uterus and deciduoma.

BACKGROUND: [corrected] Mifepristone is a synthetic antiprogestin which terminates early pregnancy. Since it interferes with the progesterone maintained decidua, we compared the effect of mifepristone on oestrogen and progesterone receptors, and on the biotransformation of these hormones in normal and deciduous uterus. METHODS: Ovariectomized rats were treated with an oestrogen-progesterone hormone regimen and deciduoma was induced by trauma in one horn of the rat uterus while the other served as a control under an identical hormonal milieu. Hormone receptor and biotransformation studies were done using radiolabelled oestradiol and progesterone with high specific activity. RESULTS: The artificially formed decidual tissue was comparable with that of early pregnancy. Mifepristone replenished oestrogen and progesterone receptors which were suppressed by progesterone in both the normal and decidualized uterine horns. Inhibition of oestrogen receptors by progesterone correlated with decreased oestradiol levels at the site of action. Metabolism of progesterone to less potent compounds was promoted by mifepristone. The enzymatic activities of 17beta-hydroxysteroid dehydrogenase (which metabolizes oestradiol), and 20alpha-hydroxysteroid dehydrogenase and 5alpha-reductase (which metabolize progesterone) were altered by mifepristone. CONCLUSION: The effect of mifepristone in varying the hormone receptor population and the availability of different levels of active metabolites of ovarian hormones have an Important role in the antiprogestin action of mifepristone.

Additive Estrogenic Activities of the Binary Mixtures of Four Estrogenic Chemicals in Recombinant Yeast Expressing Human Estrogen Receptor

To evaluate the estrogenic activities of several chemicals such as 17 beta-estradiol (E2), rho-nonylphenol, bisphenol A, butylparaben, and combinations of these chemicals, we used recombinant yeasts containing the human estrogen receptor [Saccharomyces cerevisiae ER + LYS 8127]. We evaluated E2 was most active in the recombinant yeast assay, followed by rho-nonylphenol, bisphenol A, butylparaben. The combinations of some concentrations of 17-estradiol as a strong estrogen and bisphenol A or butylparaben as a weak estrogen showed additive estrogenic effects. Also, the combinations of some concentrations of nonlyphenol and butylparaben and combination of butylparaben and bisphenol A showed additive effects in the estrogenic activity. Therefore, the estrogenic activities of the combinations of two chemicals were additive, not synergistic.

Protective role of estrogen in the neurodegenerative disorders.

Estrogen is an anabolic hormone of gonadal cells and it also modulates the growth and differentiation of non-gonadal cells like neuron/glia and protects them against the injury. The anabolic or protective actions of estrogen on the neuronal cells are mediated by the modulation of intracellular factors such as insulin like growth factor (IGF-I), tyrosine kinase A (Trk A), nerve growth factors (NGF) etc. It also modulates the action of neurotrophins which in turn regulate the synaptogenesis, synaptic plasticity and synaptic functions. By these actions estrogen prevents or slows down the neurodegenerative process.

Assessment of response to tamoxifen among Iraqi patients with advanced breast cancer

Eighty-eight women presenting with locally advanced or metastatic breast cancer were treated with tamoxifen alone. Estrogen and progesterone receptors [ER and PR] were immunocytochemically analysed in mammary tumour cells obtained by fine needle sampling from 73 patients. Of the breast carcinomas, 34.2% were ER+/PR+ and 43.8% were ER-/PR-. The ER+ content increased with age in postmenopausal women. After tamoxifen treatment objective remission occurred in 39.7% of the women. The overall response rate was 53.3% in the ER+/PR- group and 73.1% in the ER+/PR+ group. However, the response elicited in a case of the ER-/PR- phenotype justified the randomized use of tamoxifen among patients in Iraq where the necessary requirements for hormone receptor assessment are almost unavailable

CDRI-85/287: studies on competition to estrogen binding sites in the immature rat uterus.

Ability of compound CDRI-85/287, a new nonsteroidal antiestrogen with negligible inherent estrogenicity, to inhibit uptake of 3H-estradiol (3H-E2) by the immature rat uterus in vivo was investigated. Different doses of 85/287 were administered either intraperitoneally 30 min before 3H-E2 or orally 1 and 6 hr before 3H-E2. A dose dependent inhibition in 3H-E2 uptake was observed after administration of the compound by either route and was 69% at 50 micrograms/rat ip dose and 80% at 2.5 mg/kg po dose. In in vitro competitive binding assay, however, the compound showed poor affinity (RBA 0.42% of estradiol-17 beta) for cytosolic estrogen receptors. Considering the potent anti-estrogenic as well as anti-implantation efficacy of the compound, its action in vivo appears to be mediated via its active metabolite(s).

Duration of antiestrogenecity of compound CDRI-85/287: a new orally active nonsteroidal antiimplantation agent.

Duration of antiestrogenic and antiimplantation action of CDRI-85/287, (2-(4-(2-N-piperidino)ethoxy phenyl)-3-phenyl(2H)benzo(2)pyran), was studied in rat. Pretreatment of ovariectomized immature rats with this compound caused translocation of cytoplasmic estrogen receptor (ER) to the nucleus and a marked depletion of cytoplasmic ER pool resulting in a nonresponsive state of the uterus to subsequent estrogen administration until day 4. While in rats pretreated with estradiol, increased cytoplasmic ER level made the uterus responsive to a second injection of estrogen. In the delayed implantation model, 85/287 pretreated rats were given estrone on days 4, 5 or 6 post-antiestrogen treatment. No implantations were observed after estrone administration on day 4, but were present when estrone was given on days 5 or 6. Summation of these results suggests the duration of action of 85/287 to be 3-4 days in rat.

Hormonal effects on unoccupied estrogen receptors in nuclei of anterior pituitary glands

Se determinaron los receptores libres nucleares en pituitarias anteriores de ratas ovariectomizadas-adrenalectomizadas luego de la extracción de los núcleos purificados con KCL 0.4 M y la posterior incubación del extracto con 2.5 nM (3H)-estradiol (E2) durante 1.5 h a 0-4-C. Se observó unión de alta afinidad y baja capacidad en ratas no tratadas y la concentración de receptor se duplicó después de la administración de E2 durante 4 días, mientras que el tratamiento agudo (60 m) no tuvo efecto. La exposición prolongada a dietilestilbestrol (3 meses) produjo una regulación negativa tanto de los receptores nucleares libres como de los totales. El tamoxifen aumentó los receptores libres nucleares, indujo el receptor progestínico en citosol e inhibió la prolactina sérica inducida por E2, pero no la estimulación estrogénica de los receptores libres nucleares. La progesterona y testosterona no tuvieron efecto sobre los sitios nucleares libres tanto basales como estimulados por E2, mientras que la dexametasona redujo los primeros pero no los últimos. Finalmente, del 33 al 36% de los receptores libres nucleares unidos a (3H)-E2 fueron retenidos en columnas de ADN-celulosa, ya sea que la incubación con el ligando se llevara a cabo a baja temperatura (0-4-C) o alta temperatura (25-C). La unión de ADN-celulosa no cambió luego del tratamiento corto con E2 pero aumentó después de 4 días de E2. Estos dados sugieren la regulación de los recptores libres nucleares para estradiol por el ligando como así también por antiestrógenos y corticoides en la pituitaria anterior. Los sitios nucleares libres podrían ser una fracción de los receptores celulares totales que estuvieran en el estado transformado y que se unieran más fuertemente a los núcleos in vivo, como lo indican los resultados de unión a ADN-celulosa in vitro (AU) &P