Uterotrophic Activity Research Articles

Unconventional isoquinoline-based SERMs elicit fulvestrant-like transcriptional programs in ER+ breast cancer cells

Estrogen receptor alpha (ERα) is a ligand-dependent master transcriptional regulator and key driver of breast cancer pathology. Small molecule hormones and competitive antagonists favor unique ERα conformational ensembles that elicit ligand-specific transcriptional programs in breast cancer and other hormone-responsive tissues. By affecting disparate ligand binding domain structural features, unconventional ligand scaffolds can redirect ERα genomic binding patterns to engage novel therapeutic transcriptional programs. To improve our understanding of these ERα structure-transcriptional relationships, we develop a series of chemically unconventional antagonists based on the antiestrogens elacestrant and lasofoxifene. High-resolution x-ray co-crystal structures show that these molecules affect both classical and unique structural motifs within the ERα ligand binding pocket. They show moderately reduced antagonistic potencies on ERα genomic activities but are effective anti-proliferative agents in luminal breast cancer cells. Interestingly, they favor a 4-hydroxytamoxifen-like accumulation of ERα in breast cancer cells but lack uterotrophic activities in an endometrial cell line. Importantly, RNA sequencing shows that the lead molecules engage transcriptional pathways similar to the selective estrogen receptor degrader fulvestrant. This advance shows that fulvestrant-like genomic activities can be achieved without affecting ERα accumulation in breast cancer cells.

Abstract 4043: KSHN001034: An intramuscular prodrug of fulvestrant to treat estrogen-receptor (ER) positive advanced metastatic breast cancer

Abstract Purpose: Breast cancer (BC) remains a considerable health concern, with over 75% of total cases accounting for ER+ BC. Fulvestrant, a selective estrogen receptor degrader (SERD), is the primary drug of choice for treating advanced metastatic ER+, BC. Currently, Faslodex® (500 mg) is given as an intramuscular (IM) depot that achieves the steady-state plasma concentration of 24-28 ng/mL of fulvestrant from day 28 onwards. Additionally, clinical studies suggest that current Faslodex® (500 mg) achieves insufficient blockade of ERα receptor plausibly due to suboptimal physicochemical and pharmacokinetic (PK) properties. Hence, achieving higher fulvestrant plasma concentrations is a significant unmet need to improve efficacy and inhibit the development of drug resistance. To overcome these issues, we modified the physicochemical properties of the fulvestrant to enhance its solubility by developing a prodrug, KSHN001034, with the potential to deliver higher fulvestrant plasma exposures. Methods: KSHN001034 was evaluated for its physicochemical and ADME properties. Thermodynamic solubility and liver microsomal stability were performed. KSHN001034 was formulated as 100 mg/mL compared with Faslodex (50 mg/mL). Single-dose PK studies were performed using KSHN001034 in Sprague Dawley (SD) rats and Beagle Dogs post-IM administration for 7 and 14 days, respectively. The uterotrophic activity was investigated by determining changes in uterine weight in juvenile female SD rats for KSHN001034 (10 mg/kg, IP) and fulvestrant (25 mg/kg, SC). The ERα expression was also evaluated in rat uterus tissue via a simple western assay. Results: A remarkable improvement (~1100 fold) was achieved for KSHN001034 in aqueous solubility (1.112 mg/mL) vs. fulvestrant (<1 µg/mL). Significant improvement was observed in metabolic stability vs. fulvestrant. KSHN001034 showed significant improvement in PK exposure of fulvestrant upon IM administration in rats and dogs with higher AUC and Cmax compared to that of Faslodex. Relative bioavailability of fulvestrant post-KSHN001034 treatment was found to be >6-fold in rats and ~2.5 fold in dogs compared to Faslodex. Treatment of KSHN001034 antagonized estradiol (E2)-mediated uterine stimulation, exhibiting significant inhibition (85%) of uterotrophic activity vs. fulvestrant (73%). KSHN001034 reduced E2-induced uterus weight, supporting efficacy due to released fulvestrant as it is a true SERD. Additionally, KSHN001034 significantly inhibited the E2-induced ERα expression in rat uterus. Conclusions: Overall, KSHN001034 indicates the potential to deliver higher fulvestrant concentrations that would effectively block the ERα receptor resulting in improved efficacy and minimal emergence of resistance. Further, enhanced solubility and reduced injection volume would result in better patient compliance. Citation Format: Heta Pandya, Ganesh Sangle, Vishal Unadkat, Vishal Goswami, Parva Purohit, Chirag Mehta, Sonam Sinha, Ketan Variya. KSHN001034: An intramuscular prodrug of fulvestrant to treat estrogen-receptor (ER) positive advanced metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4043.

Structure-based design and synthesis of conformationally constrained derivatives of methyl-piperidinopyrazole (MPP) with estrogen receptor (ER) antagonist activity

Nuclear Estrogen receptors (ER) are cytoplasmic proteins; translocated to the nucleus to induce transcriptional signals after getting bound to the estrogen hormone. ER activation implicated in cancer cell proliferation of female reproductive organs. Thus, the discovery of ER antagonists is a reliable strategy to combat estrogen-dependent breast cancer. Endometrial carcinoma is one of the complications encountered upon long-term therapy by selective estrogen receptor modulators (SERMs) like Tamoxifen (TMX) and methyl piperidinopyrazole (MPP). Thus, the ER-full antagonist is a solution to improve the safety of this class of therapeutics during the treatment of breast cancer. We selected MPP as a lead structure to design conformationally constrained analogs. Structural rigidification is a proven strategy to transform the SERMs into full antagonists. Accordingly, we synthesized 7-methoxy-3-(4-methoxyphenyl)-4,5-dihydro-2H-benzo[g]indazoles (4), (6a-c),(8–12) along with the biphenolic counterparts(13–19)that are the anticipated active metabolites. The 4-nitrophenyl derivative(4)is with the most balanced profile regardingthe in vivoanti-uterotrophic potential (EC50 = 4.160 μM); and the cytotoxicity assay of the corresponding active metabolite(13)against ER+ breast cancer cell lines (MCF-7 IC50 = 7.200 μM, T-47D IC50 = 11.710 μM). The inconsiderable uterotrophic activities of the elaborated ER-antagonists and weak antiproliferative activity of the compound(13)against ovarian cancer (SKOV-3 IC50 = 29.800 μM) highlighted it as a good start point to elaborate potential ER-full antagonists devoid of endometrial carcinoma. Extending the pendant chain that protrudes from the 2-(4-(substituted)-phenyl) ring of the new benzo-indazoles is recommended for enhancing the potency based on the binding mode of compound(13)in the ligand-binding domain (LBD) of ER.

Selective Estrogen Receptor Modulator-Like Activities of Herba epimedii Extract and its Interactions With Tamoxifen and Raloxifene in Bone Cells and Tissues.

Herba epimedii (HEP), a kidney-tonifying herb, has been commonly used alone or in formula for strengthening kidney function and treating bone disorders. Its bone protective activity has been demonstrated to be via estrogen receptor (ERs). HEP activates the phosphorylation of ERα in an estrogen response element- (ERE-) dependent manner. We examined the bone protective effects of HEP and its potential interactions with Selective Estrogen Receptor Modulators (SERMs, such as tamoxifen and raloxifene) as they act via the same ERs. Six-month-old mature Sprague Dawley sham-operated (Sham) or ovariectomized (OVX) rats were treated with either vehicle, 17ß-estradiol (1.0 mg/kg.day), tamoxifen (Tamo, 1.0 mg/kg.day), raloxifene (Ralo, 3.0 mg/kg.day), HEP (0.16 g/kg.day), or its combinations with respective SERMs (HEP + Tamo; HEP + Ralo) for 12 weeks. HEP and SERMs as well as their combinations significantly restored changes in bone mineral density (BMD), trabecular bone properties, and bone turnover biomarkers induced by ovarian sex hormone deficiency in ovariectomized rats. Besides the increase in serum estradiol, inhibition on follicle stimulating hormone (FSH) might also be involved in the osteoprotective activities of HEP and SERMs. HEP interacted with SERMs to protect bones from ovarian sex hormone deficiency without altering SERMs’ bone protective activities. HEP neither induced changes in uterus weight nor altered the uterotrophic activity of SERMs in OVX rats. In human osteosarcoma MG-63 cells, HEP-treated serum (HEP-Ts) significantly promoted alkaline phosphatase (ALP) activity like the crude HEP extract did but did not stimulate ERE activity. Our study also reported that biologically activated HEP interacted with SERMs to promote ALP activity without altering the action of SERMs at most of the concentrations tested in MG-63 cells. HEP exerted bone protective activity and the use of HEP did not alter the bone protective activities of SERMs when they were used simultaneously in an estrogen-deficient rat model.

Abstract 3452: Pre-clinical development of next generation selective estrogen receptor degrader - SAR439859

Abstract Abstract: Nearly 70% or more of newly diagnosed cases of breast cancer (BC) are estrogen receptor positive (ER+) where endocrine therapy is a primary treatment. However, substantial evidence describes a continued role of ER signaling in tumor progression, where approximately 40% of patients on endocrine therapy develop resistance that include mutations in ER that drive a constitutively active receptor. SAR439859 is a novel next generation SERD (selective estrogen receptor degrader) with potent antagonist and degradation activity against ER both wild type and mutant and currently evaluated as a single agent and in combination with palbociclib in a Phase I/II clinical trial (NCT03284957). Here we describe the preclinical development of this molecule in multiple xenografts and demonstrated significant anti-tumor efficacy/regression in ER+ BC models including MCF7-ESR1 mutant-Y537S and endocrine therapy resistant patient-derived xenograft tumor models. The molecule also demonstrated strong synergistic activity with CDK4 inhibitor palbociclib. SAR439859 has a favorable safe profile and no uterotrophic activities. Collectively, these results show that SAR439859 is an oral, selective estrogen receptor antagonist and degrader that could provide therapeutic benefit to ER+ breast cancer patients. In conclusion, SAR439859 demonstrates broad anti-tumor activity in ER+ breast cancer cell line/PDX models. Anti-tumor efficacy correlates with PK exposure/PD modulation in target tissue. SAR439859 also has synergistic activity with CDK4 inhibitor Palbociclib. Citation Format: Fangxian Sun, Jane Cheng, Amy Sullivan, Natalia Malkova, Maysoun Shomali, Jesseca McManus, Mikhail Levit, Dinesh Bangari, Youssef El-Ahmad, Sukhvinder Sidhu, Laurent Debussche, Monsif Bouaboula. Pre-clinical development of next generation selective estrogen receptor degrader - SAR439859 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3452.

Estrogenic Effect of Salvia officinalis Extract on Reproductive Function of Female Mice and Identification of Its Phenolic Content.

Natural Phytoestrogens present in plants are effective hormonal replacement therapy. They are converted to estrogenic substances in the gastrointestinal tract, which is considered as the natural alternative to estrogen substitute treatment for postmenopausal women. Salvia officinalis, a herb traditionally used to ameliorate postmenopausal complications, can provide a safe alternative to synthetic pharmaceuticals for the treatment of menopause. Therefore, it is conceivable to detect the possible estrogenic effect of Salvia Officinalis extract as an estrogen replacement therapy in female mice. Phytochemical, pharmacological, and immune histopathological techniques are adopted in this study. HPLC is used for the identification of extracted constituents of sage herb. The uterotrophic activity of the extract was determined in immature female mice. Moreover, the mean thickness and luminal epithelium and the photomicrographs of the luminal epithelium of the uterus were also studied. HPLC revealed that quercetin is the major extracted constituent (28.6%) of the total components. Saliva officinalis extract produced a significant increase in the uterine dry weight of equal potency to estrogen. The uterus exhibited a significant increase in luminal epithelial cell height (43.3 ± 6.1μm and 36.5 ± 2.5μm) for estradiol and sage extract, respectively, compared with the control group (18.2 ± 3.5μm). Furthermore, the endometrium showed the lining epithelium formed of a single layer of columnar epithelium. The stroma seemed more voluminous with dilated vasculature. Conversely, the myometrium within the uterus was not affected in any of the experimental groups. The sage herbs induced proliferative changes in the uteri of treated mice, which suggest possible estrogenic properties. Saliva officinalis extract can be used as a hormonal replacement for women during menopause and could be further explored for contraceptive use.

English

Mistletoes are hemi-parasitic plants widely distributed around the world, used in folk medicine to treat many diseases including diabetes, hypertension, menopausal syndrome and as complementary or adjuvant treatment for cancer. The objective of the present work was the evaluation of oestrogenic activity of hydromethanolic extract of mistletoe Struthanthus venetus dried leaves (StvHME), to evaluate its potential benefits in menopause and breast cancer, which have not been reported so far. Uterotrophic activity was evaluated in immature female CD1 mice, administering StvHME (10, 100 and 500 mg/kg) for three consecutive days compared to the natural hormone 17β-oestradiol (E2, 10 μg/kg). Comparison of the MCF-7 positive oestrogen receptor human breast adenocarcinoma cell proliferation in the presence of StvHME (0.5, 5 and 50 μg/ml) or E2 (10-12-10-10M) related to untreated control cells was assessed using MTT cell viability assay. StvHME, produced biphasic effects in mice uteri; low doses (10 mg/kg) decreased uterine weight (15-38%; p<0.05), while a higher dose (500 mg/kg) increased uterine weight (28-36%; p<0.05). StvHME concentrations tested inhibited MCF-7 cell proliferation, contrasting with E2 which increased it. StvHME (50 μg/ml) antagonized the proliferative response to E2 (10-12 to 10-10 M) behaving as an anti-oestrogen. The antiproliferative response of StvHME (50 μg/ml) showed synergism with the oestrogen antagonists Tamoxifen and Fulvestrant (ICI 182,780). Our results suggest the presence of oestrogenic and anti-oestrogenic components in the StvHME that could be acting through the oestrogen ERα and ERβ receptors. Therefore, StvHME has potential utility as a complementary therapy for breast cancer. Key words: mistletoe, Struthanthus venetus, MCF-7 cells, oestrogenicity, anti-oestrogenic, anti-cancer, menopause. &nbsp

Design, synthesis, estrogenic and antiestrogenic activities of some triarylpyrazole derivatives

New triarylpyrazole derivatives, substituted with basic side chain, polar group or heterocyclic ring were designed and synthesized. Nineteen compounds were tested for their in vivo uterotrophic activity. Animals treated with compounds 9, 15a, 15c, 19a, 19f, 20a, and 21b showed pronounced increase in uterine weight. It is worth mentioning that compound 19f was more active than estradiol as an estrogenic compound as evidenced by the increased dry uterine weight. Additionally, compound 19a produced 128.25% increase in dry uterine weight relative to estradiol. On the other hand, eight compounds were screened for their in vivo antiuterotrophic activity. Animals treated with compounds 5e, 5f, 8, and 13b showed pronounced decrease in uterine weight. The highest antiuterotrophic effect was observed in mice receiving compound 13b, which was as potent as the positive control, tamoxifen as evident by the decrease in the uterine wet weight.

The estrogenicity of methylparaben and ethylparaben at doses close to the acceptable daily intake in immature Sprague-Dawley rats.

The estrogenicity of parabens at human exposure levels has become a focus of concern due to the debate over whether the estrogenicity of parabens is strong enough to play a role in the increased incidence of breast cancer. In this study, the uterotrophic activities of methylparaben (MP) and ethylparaben (EP) at doses close to the acceptable daily intake as allocated by JECFA were demonstrated in immature Sprague-Dawley rats by intragastric administration, and up-regulations of estrogen-responsive biomarker genes were found in uteri of the rats by quantitative real-time RT–PCR (Q-RT-PCR). At the same time, the urinary concentrations of MP and EP, as measured by gas chromatography–mass spectrometry (GC-MS) in rats that received the same doses of MP and EP, were found to be near the high urinary levels reported in human populations in recent years. These results show the in vivo estrogenicity of MP and EP at human exposure levels, and indicate that populations exposed to large amounts of MP and EP may have a high burden of estrogenicity-related diseases. In addition, a molecular docking simulation showed interaction between the parabens and the agonist-binding pocket of human estrogen receptor α (hERα).

Estrogens and Coronary Artery Disease: New Clinical Perspectives.

In premenopausal women, endogenous estrogens are associated with reduced prevalence of arterial hypertension, coronary artery disease, myocardial infarction, and stroke. Clinical trials conducted in the 1990s such as HERS, WHI, and WISDOM have shown that postmenopausal treatment with horse hormone mixtures (so-called conjugated equine estrogens) and synthetic progestins adversely affects female cardiovascular health. Our understanding of rapid (nongenomic) and chronic (genomic) estrogen signaling has since advanced considerably, including identification of a new G protein-coupled estrogen receptor (GPER), which like the "classical" receptors ERα and ERβ is highly abundant in the cardiovascular system. Here, we discuss the role of estrogen receptors in the pathogenesis of coronary artery disease and review natural and synthetic ligands of estrogen receptors as well as their effects in physiology, on cardiovascular risk factors, and atherosclerotic vascular disease. Data from preclinical and clinical studies using nonselective compounds activating GPER, which include selective estrogen receptor modulators such as tamoxifen or raloxifene, selective estrogen receptor downregulators such as Faslodex™ (fulvestrant/ICI 182,780), vitamin B3 (niacin), green tea catechins, and soy flavonoids such as genistein or resveratrol, strongly suggest that activation of GPER may afford therapeutic benefit for primary and secondary prevention in patients with or at risk for coronary artery disease. Evidence from preclinical studies suggest similar efficacy profiles for selective small molecule GPER agonists such as G-1 which are devoid of uterotrophic activity. Further clinical research in this area is warranted to provide opportunities for future cardiovascular drug development.

Estrogenic activity of isoflavonoids from the stem bark of the tropical tree Amphimas pterocarpoides, a source of traditional medicines

Various preparations of the African tree Amphimas pterocarpoides Harms are traditionally used to treat endocrine- related adverse health conditions. In the ovariectomized rat, the enriched in phenolics fraction of the methanol extract of stem bark of A. pterocarpoides acted as vaginotrophic agent of considerably weaker uterotrophic activity compared to estradiol. Evaluation of the fraction and 11 isoflavonoids isolated therefrom using Ishikawa cells and estrogen receptor (ER) isotype-specific reporter cells suggested that the estrogenic activity of the fraction could be attributed primarily to daidzein and dihydroglycitein and secondarily to glycitein. The potency-based selectivity of daidzein, dihydroglycitein and glycitein for gene expression through ERβ versus ERα, expressed relative to estradiol, was 37, 27 and 20, respectively. However, the rank order of relative-to-estradiol potencies of induction of alkaline phosphatase in Ishikawa cells, a reliable marker of estrogenic activity, was daidzein>dihydroglycitein>>glycitein. The considerably higher estrogenic activity of dihydroglycitein compared to glycitein could be attributed to the partial agonist/antagonist activity of dihydroglycitein through ERβ. Calculation of theoretical free energies of binding predicted the partial agonism/antagonism of dihydroglycitein through ERβ. The fraction and the isolated isoflavonoids promoted lactogenic differentiation of HC11 mammary epithelial cells at least as effectively as premenopausal levels of estradiol. This data suggests that the estrogenic activity of the fraction likely depends on the metabolism of glycitein to dihydroglycitein; that the fraction could exert vaginotrophic activity likely without challenging endocrine cancer risk more than estrogen-alone supplementation; and that the fraction's safety for the reproductive track warrants a more detailed evaluation.

Positive skeletal effect of two ingredients of Psoralea corylifolia L. on estrogen deficiency-induced osteoporosis and the possible mechanisms of action

Estrogen replacement therapy (ERT) is utilized as a major regime for treatment of postmenopausal osteoporosis at present. However, long-term supplement of estrogen may cause uterine hyperplasia and hypertension leading to a high risk of endometrial cancer and breast cancer. Psoralea corylifolia L. has long been used as tonic and food additives in many countries. Previous studies had found two ingredients in P. corylifolia L.: bavachin and bakuchiol exhibited osteoblastic activity. The present study was designed to investigate the protective effect of bakuchiol and bavachin on ovariectomy-induced bone loss and explore the possible mechanism. In vivo, bakuchiol and bavachin could prevented estrogen deficiency-induced bone loss in ovariectomized rats without uterotrophic activity. In vitro studies suggested that bakuchiol and bavachin induced primary human osteoblast differentiation by up-regulating the Wnt signalling pathway. This study suggests that such a bone-protective role makes them a promising and safe estrogen supplement for the ERT.

Abortifacient potential of methanolic extract of Anthocephalus cadamba stem bark in mice

Ethnopharmacological relevanceMedicinal plants possessing abortifacient activity have been used traditionally for a long time in folk medicine. Anthocephalus cadamba, is one such herb that has been known to possess abortifacient potential in ethnobotanical literature, but has not been validated scientifically. Materials and methodsThe methanolic extract of Anthocephalus cadamba stem bark (MEAC) was prepared and tested for abortifacient, estrogenic and uterotrophic activity. Pregnant Swiss albino mice were randomized into 5 groups (1–5). Group 1 (negative control) received 0.2% w/v agar, group 2–4 (received extract at the dose of 500, 1000 and 1500mg/kg b.w.) and group 5 received mifepristone at a dose of 5.86mg/kg b.w. respectively, by oral route from 10th to 18th day post-coitum daily, and various parameters recorded. The uterotrophic bioassay was performed in bilaterally ovariectomized mice dosed from 9th to 15th day of ovariectomy and change in uterotrophic parameters was observed. ResultsPreliminary phytochemical screening revealed presence of glycosides, alkaloids, steroids, saponins, triterpenoids, flavonoids and tannins. No signs of clinical toxicity were observed at any time during the period of treatment. The extract significantly reduced (P<0.05) the number of live fetus, weight and survival ratio of the fetus, number of corpora lutea, progesterone, estradiol and luteinizing hormone whereas the number of dead fetus, number of mice that aborted, percentage vaginal opening and post-implantation loss increased significantly (P<0.05). The estrogenicity experiments showed increase in uterine weight (P<0.05), ballooning of uterus, uterine glucose (P<0.05) and ALP (P<0.001) in extract treated group dose dependently. In addition, the extract also induced vaginal bleeding preceding parturition. ConclusionThis study has substantiated the abortifacient potential of the methanolic extract of Anthocephalus cadamba stem bark. The activity was more marked in 1000 and 1500mg/kg b.w. of the extract and was comparable to that of mifepristone. The mechanism of abortion could possibly be through changes in the uterine mileu, altered hormone levels, luteolysis and partly, estrogenicity. This study thus justifies the ethnobotanical claim of MEAC as an abortifacient.

G protein-coupled estrogen receptor protects from atherosclerosis.

Coronary atherosclerosis and myocardial infarction in postmenopausal women have been linked to inflammation and reduced nitric oxide (NO) formation. Natural estrogen exerts protective effects on both processes, yet also displays uterotrophic activity. Here, we used genetic and pharmacologic approaches to investigate the role of the G protein-coupled estrogen receptor (GPER) in atherosclerosis. In ovary-intact mice, deletion of gper increased atherosclerosis progression, total and LDL cholesterol levels and inflammation while reducing vascular NO bioactivity, effects that were in some cases aggravated by surgical menopause. In human endothelial cells, GPER was expressed on intracellular membranes and mediated eNOS activation and NO formation, partially accounting for estrogen-mediated effects. Chronic treatment with G-1, a synthetic, highly selective small molecule agonist of GPER, reduced postmenopausal atherosclerosis and inflammation without uterotrophic effects. In summary, this study reveals an atheroprotective function of GPER and introduces selective GPER activation as a novel therapeutic approach to inhibit postmenopausal atherosclerosis and inflammation in the absence of uterotrophic activity.

Synthesis and investigation of biological properties of modified 6-oxa-estra-1,3,5(10),8(9)-tetraenes

To investigate the relationship between structure and biological activity of analogues of steroid estrogens we have developed the synthesis of 7α-methyl-6-oxa-estra-1,3,5(10),8(9)-tetraenes with cis- and trans-junction of C and D rings. We found that such compounds have stronger osteoprotective, cholesterol-lowering and antioxidant properties in comparison with uterotrophic activity; that is the advantage in comparison with clinically used 17α-ethynylestradiol.

The effects of bazedoxifene in the ovariectomized aged cynomolgus monkey

Bazedoxifene (BZA) is a novel selective estrogen receptor modulator in clinical development for the prevention and treatment of postmenopausal osteoporosis. This preclinical study evaluated the efficacy and safety of BZA in preventing ovariectomy (OVX)-induced bone loss in aged cynomolgus monkeys. Animals (18 per group) underwent OVX and were administered BZA (0.2, 0.5, 1, 5, or 25mg/kg/day) or vehicle, or were sham-operated and administered vehicle, by daily oral gavage for 18months. Biochemical markers of bone turnover were assessed at 6, 12, and 18months, along with bone densitometry using dual energy X-ray absorptiometry and peripheral quantitative computed tomography. Animals were killed after 18months. Uterine and pituitary weights were determined, and histomorphometric and biomechanical measurements were performed. OVX vehicle controls showed increases in bone turnover associated with cancellous and cortical bone osteopenia (in vivo), and slight decreases (not statistically significant) in biomechanical strength parameters at the lumbar spine and femoral neck. BZA partially preserved cortical and cancellous bone mass by preventing the OVX-induced increases in bone turnover. Although the response was often similar among BZA-treated groups, the strongest efficacy was generally seen at 25mg/kg/day. Treatment with BZA did not adversely affect measures of bone strength and was well tolerated; there was no evidence of uterotrophic activity, mammary tissue was unaffected, and there were no adverse effects on plasma lipids. Treatment of ovariectomized animals with BZA partially prevented changes in bone remodeling that correlated with increases in bone mineral density, while maintaining bone strength and a favorable safety profile.

Synthesis and Biological Evaluation of the Salicylamide and Salicylic Acid Derivatives as Anti-Estrogen Agents

Alkylphenols have xenoestrogenic activity, which mimic the action of physiological estrogens and these mimicking activities are mainly mediated by nongenomic pathway. Nongenomic pathway plays a pivotal role in breast, endometrial and ovarian cancers' growth and development. In this study, various alkylphenol derivatives were prepared and screened for their anti-uterotrophic and uterotrophic activity. Among these compounds, 2-hydroxy-5-nonanoylbenzamide (compound 1b) showed 93.99% inhibitory activity in the anti-uterotrophic test performed, and was found inactive in the uterotrophic activity test. Moreover, all test compounds were examined for the effect on uterine histopathological changes, and plasma 17β-estradiol (E2) level. Compound 1b was also tested for in vitro anti-cancer activity against ER+, human breast cancer cell line MCF-7, and it reduced cell viability to 74.01% at 50 nM concentration.

Z‐Bisdehydrodoisynolic Acid (Z‐BDDA), a putative estrogenic seco‐steroid, induces profound lordosis behavior in ovariectomized female rats

Z‐Bisdehydrodoisynolic Acid (Z‐BDDA) has been described as highly estrogenic, and a selective estrogen receptor modulator, based exclusively on uterotrophic activity in female rats. Exploring possible neuroprotective effects of Z‐BDDA, we thought it important to determine whether Z‐BDDA has estrogenic effects in the brain. Accordingly, female Sprague‐Dawley rats were ovariectomized (ovx) under isofluorane anesthesia and assigned to various steroid treatment protocols intended to induce sexual receptivity. Z‐BDDA (300ug/rat or 30ug/rat) or Estradiol benzoate (10 ug/rat) was administered (sc) two weeks following ovx and some rats were also given Progesterone (1mg/rat) 48 hours later. Lordosis behavior was assessed by placement of female rats in an arena containing a sexually mature male rat. Mount attempts by the male and lordotic responses in the females were recorded. Results showed that female rats treated with either Z‐BDDA or Estrogen (followed or not by Progesterone) exhibited profound receptivity assessed by display of lordosis in response to male mount attempts. Thus, this study further establishes the estrogenicity of Z‐BDDA and demonstrates a positive feedback effect on the central nervous system that appears to parallel the peripheral (uterotrophic) effects of the compound. Supported by the SIU School of Medicine Center for Integrated Research in Cognitive and Neural Sciences.Grant Funding Source : None

Synthesis of some new diaryl and triaryl hydrazone derivatives as possible estrogen receptor modulators.

1,2-Bis(4-substituted phenyl)-2-methyl ethanone (2,4-dinitrophenyl)hydrazones and 1-naphthyl-1-(4-substituted phenyl)-methanone (2,4-dinitrophenyl)hydrazones have been synthesized and evaluated for their anti-implantation, uterotrophic, antiuterotrophic, anticancer and antimicrobial activities. Diphenolic hydrazone (compound 6) showed maximum uterotrophic inhibition of 70%, whereas compound 20 exhibited cytotoxicity in the range of 50-70% against MCF-7 and ZR-75-1 human malignant breast cell lines.

Impact of estradiol structural modifications (18-methyl and/or 17-hydroxy inversion of configuration) on the in vitro and in vivo estrogenic activity

It is well recognized that the majority of breast cancers are initially hormone-dependent and that 17β-estradiol (17β-E2) plays a crucial role in their development and progression. For this reason, using a compound able to block a specific enzyme involved in the last steps of the biosynthesis of 17β-E2 remains a rational way to treat estrogen-dependent diseases such as breast cancer. The present study describes the biological in vitro and in vivo evaluation of a structural modification (inversion of C18-methyl group at position 13 from β to α face) of 17β-E2 ( 1) and 17α-estradiol (17α-E2; 2). The two epimers 18-epi-17β-E2 ( 3) and 18-epi-17α-E2 ( 4) were obtained in two chemical steps by inversion of the C18-methyl of estrone using 1,2-phenylendiamine in refluxing acetic acid and reduction of ketone at position C17 with LiAlH 4. The new E2 isomers were tested on estrogen-sensitive cell lines (MCF-7 and T-47D), on estrogen-sensitive tissues (uterus and vagina of mice) and on estrogen receptor (ER) to determine their estrogenic potency relatively to natural estrogen 17β-E2 ( 1). The results show that 18-epi-17β-E2 ( 3) possesses the lower affinity for ER (RBA = 1.2%), the lower estrogenicity on estrogen-sensitive cells (1000 folds less estrogenic than 17β-E2 in MCF-7) and no uterotrophic (estrogenic) activity when tested on mice. In fact, we observed the following order of estrogenicity: 18-epi-17β-E2 ( 3) < 18-epi-17α-E2 ( 4) < 17α-E2 ( 2) ≪ 17β-E2 ( 1). These results suggest that the inversion of C18-methyl of natural 17β-E2 scaffold could be a useful strategy to decrease the estrogenicity of E2 derivatives used as enzyme inhibitors in the context of a treatment of estrogen-dependent diseases.