RESUMO
HER2-positive breast cancer is associated with aggressive behavior and reduced survival rates. Calcitriol restores the antiproliferative activity of antiestrogens in estrogen receptor (ER)-negative breast cancer cells by re-expressing ERα. Furthermore, calcitriol and its analog, EB1089, enhance responses to standard anti-cancer drugs. Therefore, we aimed to investigate EB1089 effects when added to the combined treatment of lapatinib and antiestrogens on the proliferation of HER2-positive breast cancer cells. BT-474 (ER-positive/HER2-positive) and SK-BR-3 (ER-negative/HER2-positive) cells were pre-treated with EB1089 to modulate ER expression. Then, cells were treated with EB1089 in the presence of lapatinib with or without the antiestrogens, and proliferation, phosphorylation array assays, and Western blot analysis were performed. The results showed that EB1089 restored the antiproliferative response to antiestrogens in SK-BR-3 cells and improved the inhibitory effects of the combination of lapatinib with antiestrogens in the two cell lines. Moreover, EB1089, alone or combined, modulated ERα protein expression and reduced Akt phosphorylation in HER2-positive cells. EB1089 significantly enhanced the cell growth inhibitory effect of lapatinib combined with antiestrogens in HER2-positive breast cancer cells by modulating ERα expression and Akt phosphorylation suppression. These results highlight the potential of this therapeutic approach as a promising strategy for managing HER2-positive breast cancer.
Assuntos
Neoplasias da Mama , Calcitriol/análogos & derivados , Humanos , Feminino , Lapatinib/farmacologia , Lapatinib/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Calcitriol/farmacologia , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Moduladores de Receptor Estrogênico/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor ErbB-2/metabolismo , Antagonistas de Estrogênios/uso terapêutico , Linhagem Celular TumoralRESUMO
Estrogen replacement therapy decreases some risk factors of the metabolic syndrome but increases the risk of some types of cancer. Tibolone (TIB) has shown similar neuroprotective effects as estrogens. This study aimed to evaluate the effects of TIB on metabolic parameters and the expression of sex hormone receptors in the CNS in ovariectomised rats fed with a hypercaloric diet. Sprague-Dawley female rats were ovariectomised and fed for 30 days with a standard diet (SD) or high-fat high-fructose diet (HFFD) and treated with TIB (1 mg/kg) or vehicle. At the end of the treatments, HFFD increased body weight, glucose tolerance, triglycerides and cholesterol levels, while TIB treatment decreased these parameters. Subsequently, the hippocampus, the hypothalamus and the frontal cortex were dissected. RT-PCR was performed for progesterone receptor (PR), androgen receptor (AR), estrogen receptors alpha and beta (ERα, ERß), insulin receptor (IR) and insulin-like growth factor 1 (IGF-1). HFFD altered the expression of sex hormone receptors in specific brain structures involved in the regulation of homeostasis and cognition, which highlights the importance of a healthy diet. In turn, TIB modulated the expression of these receptors, particularly in the hypothalamus.
Assuntos
Dieta Hiperlipídica , Carboidratos da Dieta , Moduladores de Receptor Estrogênico/farmacologia , Lobo Frontal/metabolismo , Hipocampo/metabolismo , Hipotálamo/metabolismo , Norpregnenos/farmacologia , Animais , Feminino , Lobo Frontal/efeitos dos fármacos , Frutose , Hipocampo/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Ovariectomia , Ratos , Ratos Sprague-Dawley , Receptor IGF Tipo 1/metabolismo , Receptor de Insulina/metabolismo , Receptores Androgênicos/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismoRESUMO
A dose-response study was made of the broad-spectrum gonadal steroid agonist tibolone (TBL) on lordosis behavior in estradiol benzoate (EB: 5 µg) primed rats. Doses of TBL (0, 1, 4, and 16 µg) were infused to the right lateral ventricle 2 h before testing. The highest dose increased lordosis quotients significantly at 240 min and 360 min following infusion. However, the intensity of lordosis was weak. In experiment 2, the TBL dose of 16 µg was selected to determine whether tamoxifen (TMX), RU486, or antide could modify the lordosis response to TBL. Infusions of the three compounds, before TBL, significantly attenuated the TBL-induced facilitation of lordosis. The results suggest that TBL stimulates lordosis by activating estrogen, progesterone, and may do so by downstream stimulation of GnRH release. The physiological role TBL plays in controlling lordosis behavior remains to be determined.
Assuntos
Moduladores de Receptor Estrogênico/farmacologia , Norpregnenos/farmacologia , Postura , Comportamento Sexual Animal/efeitos dos fármacos , Animais , Estradiol/análogos & derivados , Estradiol/farmacologia , Feminino , Antagonistas de Hormônios/farmacologia , Mifepristona/farmacologia , Oligopeptídeos/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Estrogênio/antagonistas & inibidores , Receptores LHRH/antagonistas & inibidores , Receptores de Progesterona/antagonistas & inibidoresRESUMO
Tibolone (TIB), a selective tissue estrogenic activity regulator (STEAR) in clinical use by postmenopausal women, activates hormonal receptors in a tissue-specific manner. Estrogenic activity is present mostly in the brain, vagina, and bone, while the inactive forms predominate in the endometrium and breast. Conflicting literature on TIB's actions has been observed. While it has benefits for vasomotor symptoms, bone demineralization, and sexual health, a higher relative risk of hormone-sensitive cancer has been reported. In the brain, TIB can improve mood and cognition, neuroinflammation, and reactive gliosis. This review aims to discuss the systemic effects of TIB on peri- and post-menopausal women and its role in the brain. We suggest that TIB is a hormonal therapy with promising neuroprotective properties.
Assuntos
Encéfalo/efeitos dos fármacos , Moduladores de Receptor Estrogênico/farmacologia , Menopausa/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Norpregnenos/farmacologia , Encéfalo/imunologia , Encéfalo/metabolismo , Moduladores de Receptor Estrogênico/efeitos adversos , Feminino , Humanos , Menopausa/imunologia , Menopausa/metabolismo , Norpregnenos/efeitos adversosRESUMO
Estrogen is a hormone responsible for modulating several physiological processes such as immune response and bone homeostasis. Physiological fluctuations of estrogen concentration are one of the defining principles behind its mechanism. In cases of estrogen deficiency, such as in menopausal women, a more intense bone resorption may occur due to an increase in osteoclast activity. One of the main factors that influence osteoclast formation and response is the immune system, mainly through cytokines secreted by B and T cells. The purpose of this review is to highlight how estrogen can modulate the secretion of cytokines that can alter bone physiology, thereby establishing an axis between estrogen, immune cells, and osteoclastogenesis.
Assuntos
Linfócitos B/metabolismo , Citocinas/metabolismo , Estrogênios/metabolismo , Osteogênese/fisiologia , Linfócitos T/metabolismo , Animais , Reabsorção Óssea/metabolismo , Osso e Ossos/metabolismo , Diferenciação Celular , Citocinas/genética , Moduladores de Receptor Estrogênico/metabolismo , Feminino , Regulação da Expressão Gênica/fisiologia , Humanos , Menopausa/metabolismo , Osteoclastos/metabolismoRESUMO
A síndrome dos ovários policísticos (SOP) é responsável por cerca de 80% dos casos de infertilidade anovulatória. Não há na literatura evidências suficientes para a definição do tratamento ideal da infertilidade na SOP, mas repete-se que deve ser iniciado por mudanças no estilo de vida, e frequentemente envolve a indução farmacológica da ovulação e, em casos selecionados, as técnicas de reprodução assistida e o drilling ovariano laparoscópico. Este texto pretende reunir informações atuais sobre o manejo da infertilidade em mulheres com SOP e, dessa forma, permitir ao ginecologista a escolha da melhor abordagem, de forma Individualizada e baseada nas melhores evidências disponíveis.(AU)
Assuntos
Humanos , Feminino , Síndrome do Ovário Policístico/complicações , Infertilidade Feminina/tratamento farmacológico , Anovulação/tratamento farmacológico , Indução da Ovulação/métodos , Acetilcisteína/uso terapêutico , Vitamina D/uso terapêutico , Inseminação Artificial , Corticosteroides/uso terapêutico , Moduladores de Receptor Estrogênico/uso terapêutico , Técnicas de Reprodução Assistida , Tiazolidinedionas/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Técnicas de Maturação in Vitro de Oócitos , Gonadotropinas/uso terapêutico , Infertilidade Feminina/cirurgia , Inositol/uso terapêutico , Metformina/uso terapêuticoRESUMO
La definición de sangrado ginecológico anormal durante terapia hormonal de la menopausia es aquel sangrado no programado durante el uso de la terapia. Este artículo es un pauteo que describe: 1) cuándo diagnosticar unsangrado anormal, ya que difiere según el tipo de esquema hormonal utilizado; 2) eldiagnóstico diferencial del origen del sangrado anormal; 3) los métodos de evaluación para diagnosticar el origen del sangrado. Se destacan los aspectos principales para el diagnóstico diferencial entre patología orgánica versus disrupción endometrial debida al tratamiento hormonal. Además, se describen los ajustes posibles para resolver el sangrado cuando éste se debe a disrupción del endometrio.
Abnormal bleeding related to menopausal hormone therapy is defined as unscheduled bleeding during the use of the therapy. This article outlines when to diagnose an abnormal bleeding -as this differs according to the type of hormonal scheme used-, the differential diagnosis of the origin of abnormal bleeding, and the methods of evaluation to assess the origin of the bleeding. The main aspects are highlighted on the differentiation of organic pathology versus disruption of the endometrium due to treatment. Also, treatment adjustments to resolve bleeding when it is due to disruption of the endometrium are outlined.
Assuntos
Humanos , Feminino , Hemorragia Uterina/etiologia , Menopausa , Terapia de Reposição de Estrogênios/efeitos adversos , Moduladores de Receptor Estrogênico/efeitos adversos , Norpregnenos/efeitos adversos , Pólipos/complicações , Pólipos/diagnóstico , Neoplasias do Endométrio/complicações , Neoplasias do Endométrio/diagnóstico , Moduladores de Receptor Estrogênico/uso terapêutico , Diagnóstico Diferencial , Hiperplasia Endometrial/complicações , Hiperplasia Endometrial/diagnóstico , Endométrio/diagnóstico por imagem , Metrorragia/etiologia , Norpregnenos/uso terapêuticoRESUMO
Tibolone, a synthetic steroid used for the prevention of osteoporosis and the treatment of climacteric symptoms in post-menopausal women, may exert tissue selective estrogenic actions acting on estrogen receptors (ERs). We previously showed that tibolone protects human T98G astroglial cells against glucose deprivation (GD). In this study we have explored whether the protective effect of tibolone on these cells is mediated by ERs. Experimental studies showed that both ERα and ERß were involved in the protection by tibolone on GD cells, being ERß preferentially involved on these actions over ERα. Tibolone increased viability of GD cells by a mechanism fully blocked by an ERß antagonist and partially blocked by an ERα antagonist. Furthermore, ERß inhibition prevented the effect of tibolone on nuclear fragmentation, ROS and mitochondrial membrane potential in GD cells. The protective effect of tibolone was mediated by neuroglobin. Tibolone upregulated neuroglobin in T98G cells and primary mouse astrocytes by a mechanism involving ERß and neuroglobin silencing prevented the protective action of tibolone on GD cells. In summary, tibolone protects T98G cells by a mechanism involving ERß and the upregulation of neuroglobin.
Assuntos
Astrócitos/efeitos dos fármacos , Receptor beta de Estrogênio/metabolismo , Globinas/metabolismo , Glucose/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Norpregnenos/farmacologia , Substâncias Protetoras/farmacologia , Regulação para Cima/efeitos dos fármacos , Animais , Astrócitos/metabolismo , Linhagem Celular Tumoral , Moduladores de Receptor Estrogênico/farmacologia , Receptor alfa de Estrogênio/metabolismo , Estrogênios/metabolismo , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Neuroglobina , Espécies Reativas de Oxigênio/metabolismoRESUMO
Objective To evaluate the effect of short-term hormone replacement therapy with tibolone 2.5 mg daily on endothelial function of healthy postmenopausal women, using flow-mediated dilation (FMD) of the brachial artery. Methods We performed a randomized, double-blinded, placebo-controlled study. A total of 100 healthy postmenopausal women were randomly allocated to receive tibolone (n = 50) or placebo (n = 50) for 28 days. Measurement of the FMD of the brachial artery was performed before and after the use of tibolone and placebo. Results A total of 31 women completed the study in the tibolone group, and 32 women completed the study in the control group. The results of the FMD measurements obtained from the women in the two groups before treatment were similar (0.018 and 0.091, for tibolone and placebo, p = 0.57). The values of the FMD in women who used tibolone and placebo, before and after the treatment, were similar in both groups. The numbers of women who presented an increase in the values of the FMD in both groups were also similar. Conclusion Our results demonstrate that the administration of 2.5 mg tibolone to healthy postmenopausal women for 28 days does not promote endothelial-dependent vasodilation, measured by FMD of the brachial artery.
Assuntos
Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Moduladores de Receptor Estrogênico , Norpregnenos/administração & dosagem , Artéria Braquial/fisiologia , Método Duplo-Cego , Feminino , Terapia de Reposição Hormonal , Humanos , Pessoa de Meia-Idade , Norpregnenos/efeitos adversos , Placebos , Pós-Menopausa , Estudos Prospectivos , Vasodilatação/efeitos dos fármacosRESUMO
OBJECTIVE: A prospective randomized controlled trial was conducted to evaluate the effect of low dose of tibolone on the histology, expression of estrogen (ER) and progesterone receptors (PR) and Bcl-2 protein, in endometrium of postmenopausal women. METHOD: Forty postmenopausal women consented to treatment and were allocated into two groups of 20 women: Group 1 (Control) without hormone replacement therapy (HRT); Group 2 (Tibolone) treatment at the dose of 1.25 mg/day of oral tibolone administered for a 24-week period. The effect on the endometrium was assessed by histology and the apoptosis marker Bcl-2. The immunoexpression of ER and PR were also measured. RESULTS: Tibolone group showed higher expression of ER, PR and Bcl-2 protein in glandular epithelium and stroma compared to control group. CONCLUSION: Tibolone in a daily dose of 1.25 mg during 24 weeks demonstrated endometrial action that resulted in low proliferation and was shown to lead to atrophic endometrium. It had favorable effects on the postmenopausal endometrium due to its higher immunoexpression of PR and Bcl-2 protein in endometrial glandular epithelium, thereby creating a balance between pro-apoptotic and anti-apoptotic actions.
Assuntos
Endométrio/efeitos dos fármacos , Moduladores de Receptor Estrogênico/uso terapêutico , Terapia de Reposição de Estrogênios/métodos , Norpregnenos/uso terapêutico , Método Duplo-Cego , Endométrio/metabolismo , Moduladores de Receptor Estrogênico/administração & dosagem , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Norpregnenos/administração & dosagem , Pós-Menopausa , Estudos Prospectivos , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/efeitos dos fármacos , Receptores de Estrogênio/biossíntese , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Progesterona/biossíntese , Receptores de Progesterona/efeitos dos fármacosRESUMO
The purpose of this study was to investigate antiproliferative activity of bonediol, an alkyl catechol isolated from the Mayan medicinal plant Bonellia macrocarpa. Bonediol was assessed for growth inhibition of androgen-sensitive (LNCaP), androgen-insensitive (PC-3), and metastatic androgen-insensitive (PC-3M) human prostate tumor cells; toxicity on normal cell line (HEK 293) was also evaluated. Hedgehog pathway was evaluated and competitive 3H-estradiol ligand binding assay was performed. Additionally, antioxidant activity on Nrf2-ARE pathway was evaluated. Bonediol induced a growth inhibition on prostate cancer cell lines (IC50 from 8.5 to 20.6 µM). Interestingly, bonediol binds to both estrogen receptors (ERα (2.5 µM) and ERß (2.1 µM)) and displaces the native ligand E2 (17ß-estradiol). No significant activity was found in the Hedgehog pathway. Additionally, activity of bonediol on Nrf2-ARE pathway suggested that bonediol could induce oxidative stress and activation of detoxification enzymes at 1 µM (3.8-fold). We propose that the compound bonediol may serve as a potential chemopreventive treatment with therapeutic potential against prostate cancer.
Assuntos
Antineoplásicos/farmacologia , Catecóis/farmacologia , Moduladores de Receptor Estrogênico/farmacologia , Extratos Vegetais/farmacologia , Primulaceae/química , Animais , Antineoplásicos/química , Catecóis/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Moduladores de Receptor Estrogênico/química , Células HEK293 , Humanos , Camundongos , Células NIH 3T3 , Extratos Vegetais/química , Ensaio Radioligante , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/metabolismoRESUMO
OBJECTIVE: To assess the effect of tibolone on mammary tissue of castrated rats over 3 different periods of time. METHODS: Sixty virgin female Wistar rats were submitted to oophorectomy. Twenty-one days after surgery, with hypoestrogenism confirmed, the experimental rats were randomly assigned to six groups: Tibolone 1 (n=10) received tibolone 1 mg/day for 23 days, tibolone 2 (n=10) for 59 days and tibolone 3 (n=10) for 118 days. The groups control 1 (n=8), control 2 (n=7) and control 2 (n=10) received distilled water for 23, 59 and 118 days, respectively. After treatment, all six pairs of mammary glands were removed and stained with hematoxylin and eosin (HE) for histological analysis after euthanasia. The histological parameters evaluated were: epithelial cell proliferation and secretory activity. The variables were analyzed statistically, with the level of significance set at 0.05. RESULTS: Histological changes were observed in 20/55 rats, mild epithelial hyperplasia in 7/55, moderate epithelial hyperplasia in 5/55, alveolar-nodular hyperplasia in 7/55, atypia without epithelial proliferation in 1/55, and no cases of severe epithelial hyperplasia were found. Secretory activity was observed in 31/55 rats. The secretory activity was significantly higher in the tibolone groups compared to control at all the time points assessed (p=0,001). The histological changes were did not show significance when the control and tibolone groups were compared. The time of exposure to tibolone did not show significance when the three different periods of evaluation were compared. CONCLUSION: No relation between histological modification and tibolone treatment was verified after short-, medium- and long-term treatment.
Assuntos
Moduladores de Receptor Estrogênico/farmacologia , Glândulas Mamárias Animais/efeitos dos fármacos , Norpregnenos/farmacologia , Animais , Feminino , Distribuição Aleatória , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Improved efficacy of neoadjuvant endocrine-targeting therapies in luminal breast carcinomas could be achieved with optimal use of pathway targeting agents. In a mouse model of ductal breast carcinoma we identify a tumor regressive stromal reaction that is induced by neoadjuvant endocrine therapy. This reparative reaction is characterized by tumor neovascularization accompanied by infiltration of immune cells and carcinoma-associated fibroblasts that stain for phosphorylated ribosomal protein S6 (pS6), downstream the PI3K/Akt/mTOR pathway. While tumor variants with higher PI3K/Akt/mTOR activity respond well to a combination of endocrine and PI3K/Akt/mTOR inhibitors, tumor variants with lower PI3K/Akt/mTOR activity respond more poorly to the combination therapy than to the endocrine therapy alone, associated with inhibition of stromal pS6 and the reparative reaction. In human breast cancer xenografts we confirm that such differential sensitivity to therapy is primarily determined by the level of PI3K/Akt/mTOR in tumor cells. We further show that the clinical response of breast cancer patients undergoing neoadjuvant endocrine therapy is associated with the reparative stromal reaction. We conclude that tumor level and localization of pS6 are associated with therapeutic response in breast cancer and represent biomarkers to distinguish which tumors will benefit from the incorporation of PI3K/Akt/mTOR inhibitors with neoadjuvant endocrine therapy.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/enzimologia , Carcinoma Ductal de Mama/tratamento farmacológico , Carcinoma Ductal de Mama/enzimologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Idoso , Idoso de 80 Anos ou mais , Androstadienos/farmacologia , Animais , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Moduladores de Receptor Estrogênico/farmacologia , Feminino , Humanos , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/enzimologia , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Transdução de Sinais , Células Estromais/enzimologia , Células Estromais/patologia , Wortmanina , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJETIVO: Avaliar o efeito da terapia hormonal com tibolona, em três períodos de tempo diferentes, sobre o tecido mamário de ratas castradas. MÉTODO: Foram utilizadas 60 ratas Wistar adultas e virgens, submetidas à ooforectomia. Após 21 dias de pós-operatório (PO), confirmado o hipoestrogenismo, os animais foram divididos aleatoriamente em 6 grupos: tibolona 1 (n=10) recebeu tibolona 1 mg/dia por 23 dias, tibolona 2 (n=10), por 59 dias, tibolona 3 (n=10), por 118 dias; os subgrupos controle 1 (n=8), controle 2 (n=7) e controle 3 (n=10) receberam a água destilada por 23, 59 e 118 dias, respectivamente. Após o tratamento, foram ressecados seis pares de mamas, destinados à análise histológica pela coloração de hematoxilina e eosina (HE); o procedimento seguiu de eutanásia. Os parâmetros histológicos avaliados foram: hiperplasia epitelial e atividade secretora (AS). As variáveis foram submetidas à análise estatística, adotando-se como significante p<0,05. RESULTADOS: Foram observadas alterações histológicas em 20/55 ratas, sendo: hiperplasia epitelial leve (HEB1) em 7/55, hiperplasia epitelial moderada (HEB2) em 5/55, hiperplasia alvéolo-nodular (HAN) em 7/55, atipia sem proliferação epitelial em 1/55, não sendo encontrada hiperplasia severa (HEB3). Encontrou-se AS em 31/55 das ratas. A AS foi significativamente maior no grupo tibolona (T), em todos os tempos avaliados (p=0,001). As alterações histológicas analisadas não foram significantes comparando (p>0,05) os grupos controle (C) e T. A variável tempo de exposição à droga não apresentou significância, quando comparados os três períodos avaliados. CONCLUSÃO: Não foi verificada relação entre as alterações histológicas e a terapêutica com tibolona em curto, médio e longo prazo. .
OBJECTIVE: To assess the effect of tibolone on mammary tissue of castrated rats over 3 different periods of time. METHODS: Sixty virgin female Wistar rats were submitted to oophorectomy. Twenty-one days after surgery, with hypoestrogenism confirmed, the experimental rats were randomly assigned to six groups: Tibolone 1 (n=10) received tibolone 1 mg/day for 23 days, tibolone 2 (n=10) for 59 days and tibolone 3 (n=10) for 118 days. The groups control 1 (n=8), control 2 (n=7) and control 2 (n=10) received distilled water for 23, 59 and 118 days, respectively. After treatment, all six pairs of mammary glands were removed and stained with hematoxylin and eosin (HE) for histological analysis after euthanasia. The histological parameters evaluated were: epithelial cell proliferation and secretory activity. The variables were analyzed statistically, with the level of significance set at 0.05. RESULTS: Histological changes were observed in 20/55 rats, mild epithelial hyperplasia in 7/55, moderate epithelial hyperplasia in 5/55, alveolar-nodular hyperplasia in 7/55, atypia without epithelial proliferation in 1/55, and no cases of severe epithelial hyperplasia were found. Secretory activity was observed in 31/55 rats. The secretory activity was significantly higher in the tibolone groups compared to control at all the time points assessed (p=0,001). The histological changes were did not show significance when the control and tibolone groups were compared. The time of exposure to tibolone did not show significance when the three different periods of evaluation were compared. CONCLUSION: No relation between histological modification and tibolone treatment was verified after short-, medium- and long-term treatment. .
Assuntos
Animais , Feminino , Ratos , Moduladores de Receptor Estrogênico/farmacologia , Glândulas Mamárias Animais/efeitos dos fármacos , Norpregnenos/farmacologia , Distribuição Aleatória , Ratos Wistar , Fatores de TempoRESUMO
Salpichrolides are natural plant steroids that contain an unusual six-membered aromatic ring D. We recently reported that some of these compounds, and certain analogs with a simplified side chain, exhibited antagonist effects toward the human estrogen receptor (ER), a nuclear receptor whose endogenous ligand has an aromatic A ring (estradiol). Drugs acting through the inhibition or modulation of ERs are frequently used as a hormonal therapy for ER(+) breast cancer. Previous results suggested that the aromatic D ring was a key structural motif for the observed activity; thus, this modified steroid nucleus may provide a new scaffold for the design of novel antiestrogens. Using molecular dynamics (MD) simulation we have modeled the binding mode of the natural salpichrolide A and a synthetic analog with an aromatic D ring within the ERα. These results taken together with the calculated energetic contributions associated to the different ligand-binding modes are consistent with a preferred inverted orientation of the steroids in the ligand-binding pocket with the aromatic ring D occupying a position similar to that observed for the A ring of estradiol. Major changes in both dynamical behavior and global positioning of H11 caused by the loss of the ligand-His524 interaction might explain, at least in part, the molecular basis of the antagonism exhibited by these compounds. Using steered MD we also found a putative unbinding pathway for the steroidal ligands through a cavity formed by residues in H3, H7, and H11, which requires only minor changes in the overall receptor conformation.
Assuntos
Ergosterol/análogos & derivados , Estradiol/química , Moduladores de Receptor Estrogênico/química , Receptor alfa de Estrogênio/antagonistas & inibidores , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Motivos de Aminoácidos , Sítios de Ligação , Ergosterol/síntese química , Ergosterol/química , Moduladores de Receptor Estrogênico/síntese química , Receptor alfa de Estrogênio/química , Humanos , Ligantes , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Ligação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Termodinâmica , Interface Usuário-ComputadorRESUMO
The steroidal drug Tibolone is used for the treatment of climacteric symptoms and osteoporosis in post-menopausal women. Although Tibolone has been shown to exert neuroprotective actions after middle cerebral artery occlusion, its specific actions on glial cells have received very little attention. In the present study we have assessed whether Tibolone exerts protective actions in a human astrocyte cell model, the T98G cells, subjected to glucose deprivation. Our findings indicate that Tibolone decreases the effects of glucose deprivation on cell death, nuclear fragmentation, superoxide ion production, mitochondrial membrane potential, cytoplasmic calcium concentration and morphological parameters. These findings suggest that glial cells may participate in the neuroprotective actions of Tibolone in the brain.
Assuntos
Astrócitos/efeitos dos fármacos , Moduladores de Receptor Estrogênico/farmacologia , Glucose/metabolismo , Fármacos Neuroprotetores/farmacologia , Norpregnenos/farmacologia , Astrócitos/metabolismo , Astrócitos/fisiologia , Cálcio/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismoRESUMO
BACKGROUND: This study aimed to evaluate the effect of long-term high-dose tibolone on the bladders and urethras of ovariectomized rats. METHODS: Bilateral ovariectomy was performed in 14 young adult rats randomly divided into 2 groups. Experimental rats (n = 9) received 1 mg/day of tibolone orally; control rats (n = 6) received a placebo. After 150 days, the bladders and urethras were removed. Bladder cell proliferation was analyzed by Ki-67 immunohistochemistry. A histomorphometric analysis was performed for epithelial thickness and the percent areas of collagen fibers and blood vessels. Data were compared using a Mann-Whitney test (significance level at p < 0.05). RESULTS: Urothelial thickness and the percent area of collagen fibers and blood vessels were not significantly different between the tibolone and control groups in the bladder and urethra. In addition, urothelium cell proliferation in the bladder showed a low immunopositivity in both groups. Furthermore, the glycogen and glycoprotein contents in urethral epithelium were slightly modified by tibolone and no change was observed in the bladder. CONCLUSION: Long-term administration of tibolone has no effect on urothelial trophism, collagen fibers, the number of vessels, or cell proliferation in the urethra and bladder of the ovariectomized rat.
Assuntos
Moduladores de Receptor Estrogênico/administração & dosagem , Norpregnenos/administração & dosagem , Ovariectomia , Uretra/efeitos dos fármacos , Bexiga Urinária/efeitos dos fármacos , Animais , Feminino , Glicogênio/análise , Glicoproteínas/análise , Ratos , Ratos Wistar , Uretra/anatomia & histologia , Bexiga Urinária/anatomia & histologia , Urotélio/anatomia & histologia , Urotélio/química , Urotélio/efeitos dos fármacosRESUMO
BACKGROUND: The treatment of leishmaniasis relies mostly on parenteral drugs with potentially serious adverse effects. Additionally, parasite resistance in the treatment of leishmaniasis has been demonstrated for the majority of drugs available, making the search for more effective and less toxic drugs and treatment regimens a priority for the control of leishmaniasis. The aims of this study were to evaluate the antileishmanial activity of raloxifene in vitro and in vivo and to investigate its mechanism of action against Leishmania amazonensis. METHODOLOGY/PRINCIPAL FINDINGS: Raloxifene was shown to possess antileishmanial activity in vitro against several species with EC50 values ranging from 30.2 to 38.0 µM against promastigotes and from 8.8 to 16.2 µM against intracellular amastigotes. Raloxifene's mechanism of action was investigated through transmission electron microscopy and labeling with propidium iodide, DiSBAC2(3), rhodamine 123 and monodansylcadaverine. Microscopic examinations showed that raloxifene treated parasites displayed autophagosomes and mitochondrial damage while the plasma membrane remained continuous. Nonetheless, plasma membrane potential was rapidly altered upon raloxifene treatment with initial hyperpolarization followed by depolarization. Loss of mitochondrial membrane potential was also verified. Treatment of L. amazonensis-infected BALB/c mice with raloxifene led to significant decrease in lesion size and parasite burden. CONCLUSIONS/SIGNIFICANCE: The results of this work extend the investigation of selective estrogen receptor modulators as potential candidates for leishmaniasis treatment. The antileishmanial activity of raloxifene was demonstrated in vitro and in vivo. Raloxifene produces functional disorder on the plasma membrane of L. amazonensis promastigotes and leads to functional and morphological disruption of mitochondria, which culminate in cell death.
Assuntos
Moduladores de Receptor Estrogênico/farmacologia , Leishmania mexicana/efeitos dos fármacos , Leishmaniose Cutânea/parasitologia , Cloridrato de Raloxifeno/farmacologia , Tripanossomicidas/farmacologia , Animais , Membrana Celular/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Vacúolos/efeitos dos fármacosRESUMO
INTRODUCTION: Female libido is multifactorial and complex. Declining estrogen levels in postmenopausal women affects vaginal function. AIM: The aim of this study was to evaluate female sexual function after using topical estrogen, testosterone, or polyacrylic acid as vaginal lubricants with K-Y jelly as a placebo lubricant. METHODS: This was a randomized controlled clinical trial on 80 postmenopausal women between 40 and 70 years of age with follow-up at the Menopause Clinic of the CAISM Unicamp. The women were randomized to treatment with topical vaginal estrogen, testosterone, polyacrylic acid, or oil lubricant alone, three times a week for a period of 12 weeks from November 2011 to January 2013. MAIN OUTCOME MEASURE: We used the Female Sexual Function Index (FSFI) to assess changes in sexual response at baseline, and after 6 and 12 weeks. RESULTS: After 12 weeks of treatment, polyacrylic acid and topical testosterone produced improvements in the FSFI domains of sexual desire, lubrication, satisfaction, reduced pain during intercourse, and total score compared with lubricant alone. Treatment with topical estrogen in comparison with lubricant alone showed an improvement in the FSFI field of desire. The intragroup analysis over the time of the treatment showed improvements in the fields of desire, lubrication, and reduced pain for polyacrylic acid, testosterone, and estrogen. Furthermore, women who used testosterone showed improvements over time in the fields of arousal, orgasm, and satisfaction. CONCLUSIONS: Treatment of postmenopausal women with symptoms of vaginal atrophy with polyacrylic acid, testosterone, and estrogen for 12 weeks produced improvements in self-reported female sexual function when compared with a placebo lubricant.