A SERM increasing the expression of the osteoblastogenesis and mineralization-related proteins and improving quality of bone tissue in an experimental model of osteoporosis

Raloxifene is an antiresorptive drug, selective estrogen receptor modulator (SERM) used in the treatment of osteoporosis. Objective To evaluate proteins related to bone repair at the peri-implant bone in a rat model of osteoporosis treated with raloxifene. Material and Methods 72 rats were divided into three groups: SHAM (healthy animals), OVX (ovariectomized animals), and RLX (ovariectomized animals treated with raloxifene). Raloxifene was administered by gavage (1 mg/kg/day). Tibial implantation was performed 30 days after ovariectomy, and animals were euthanized at 14, 42, and 60 days postoperatively. Samples were collected and analyzed by immunohistochemical reactions, molecular analysis, and microtomographic parameters. Results RLX showed intense staining of all investigated proteins at both time points except for RUNX2. These results were similar to SHAM and opposite to OVX, showing mild staining. The PCR gene expression of OC and ALP values for RLX (P<0.05) followed by SHAM and OVX groups. For BSP data, the highest expression was observed in the RLX groups and the lowest expression was observed in the OVX groups (P<0.05). For RUNX2 data, RLX and SHAM groups showed greater values compared to OVX (P<0.05). At 60 days postoperatively, microtomography parameters, related to closed porosity, showed higher values for (Po.N), (Po.V), and (Po) in RLX and SHAM groups, whereas OVX groups showed lower results (P<0.05); (BV) values (P=0.009); regarding total porosity (Po.tot), RLX group had statistically significant lower values than OVX and SHAM groups (P=0.009). Regarding the open porosity (Po.V and Po), the SHAM group presented the highest values, followed by OVX and RLX groups (P<0.05). The Structural Model Index (SMI), RLX group showed a value closer to zero than SHAM group (P<0.05). Conclusions Raloxifene had a positive effect on the expression of osteoblastogenesis/mineralization-related proteins and on micro-CT parameters related to peri-implant bone healing.

Pharmacotherapy for schizophrenia in postmenopausal women

INTRODUCTION

Reduced estrogen levels at menopause mean a loss of the neuroprotection that is conferred, from puberty until menopause, on women with schizophrenia. The postmenopausal stage of schizophrenia requires therapeutic attention because women with this diagnosis almost invariably experience increased symptoms and increased side effects at this time. So far, few targeted therapies have been successfully developed.

AREAS COVERED

This non-systematic, narrative review is based on the relevant published literature indexed in PubMed. A digital search was combined with a manual check of references from studies in the field of gender differences, menopause and schizophrenia. Aside from the inclusion of a few early classic papers, the review focuses on 21st century basic, psychopharmacologic, and clinical literature on the treatment of women with schizophrenia after menopause.

EXPERT OPINION

Beyond a relatively low dose threshold, all antipsychotic medications have adverse effects, which become more prominent for women at the time of menopause. Estrogen modulators may not help all symptoms of schizophrenia but are, nevertheless, relatively safe and, when used as adjuncts, help to keep antipsychotic doses low, thus reducing the side effect burden. The field is currently moving towards precision medicine and individual genetic profiles will help to determine the efficacy of available treatments in the future.

The Effect of Piperine Pro-Nano Lipospheres on Direct Intestinal Phase II Metabolism: The Raloxifene Paradigm of Enhanced Oral Bioavailability

Phase II biotransformation reactions have been gaining more attention due to their acknowledged significance in drug bioavailability, drug development, and drug-drug interactions. However, the predominant role of phase I metabolism has always overshadowed phase II metabolism, resulting in insufficient data regarding its mechanisms. In this paper, we investigate the effect of an advanced lipid based formulation on the phase II metabolism process of glucuronidation, occuring in the enterocytes monolayer. The investigated formulation is a self-emulsifying drug delivery system, termed pro-nano lipospheres, which contains the natural absorption enhancer piperine. To evaluate the effect of this formulation on direct glucuronidation we chose the model molecule raloxifene. First, glucuronidation is the main clearance pathway of this compound without involvement of preceding mechanisms. Second, raloxifene's extensive glucuronidation site is primarily at the intestine. Raloxifene's oral bioavailability was determined in a series of pharmacokinetic experiments using the freely moving rat model. In order to test the effect of the formulation on the relevant UGT enzymes reported in the clinic, we used the in vitro method of UGT-Glo Assay. Coadministration of raloxifene and piperine pro-nano lipospheres to rats resulted in a 2-fold increase in the relative oral bioavailability of raloxifene. However, coadministration of raloxifene with blank pro-nano lipospheres had no effect on its oral bioavailability. In contrast to the difference found in vivo between the two vehicles, both formulations extended an inhibitory effect on UGT enzymes in vitro. Ultimately, these findings prove the ability of the formulation to diminish intestinal direct phase II metabolism which serves as an absorption obstacle for many of today's marketed drugs. Pro-nano lipospheres is a formulation that serves as a platform for the simultaneous delivery of the absorption enhancer and a required drug. The discrepancy found between the in vivo and in vitro models demonstrates that the in vitro method may not be sensitive enough to distinguish the difference between the formulations.

Growth-suppressive activity of raloxifene on liver cancer cells by targeting IL-6/GP130 signaling

Background

Interleukin-6 (IL-6) is a multifunctional cytokine, which is involved in the regulation of differentiation and growth of certain types of tumor cells. Constitutive activation of Signal Transducer and Activator of Transcription 3 (STAT3) induced by IL-6 is frequently detected in liver cancer and has emerged as a viable molecular target for liver cancer treatment. However, few inhibitors targeting up-streams of STAT3 are available for the therapy of liver cancer. We reported the discovery of EVISTA (Raloxifene HCl) as novel inhibitor of IL-6/GP130 protein-protein interactions (PPIs) using multiple ligand simultaneous docking (MLSD) and drug repositioning. The possible effect of Raloxifene in STAT3 signaling or liver cancer cells is still unclear.

Results

Raloxifene inhibited the P-STAT3 stimulated by IL-6, but not the induction of STAT1 and STAT6 phosphorylation by IFN-γ, IFN-α, and IL-4. Raloxifene inhibited STAT3 phosphorylation and resulted in the induction apoptosis on human liver cancer cell-lines. Raloxifene inhibited the targets of STAT3, such as Bcl-2, Bcl-xl and survivin and cell viability, cell migration, and colony formation in liver cancer cells. Further, daily administration of Raloxifene suppressed the Hep-G2 tumor growth in mice in vivo.

Materials and Methods

The inhibitory effect on STAT3 phosphorylation and activity as well as cell viability, migration, and colony forming ability by Raloxifene was examined in human liver cancer cells. Tumor growth was detected via mouse xenograft tumor mode.

Conclusions

Our results suggest that Raloxifene is a potent IL-6/GP130 inhibitor and may be a chemoprevention agent for liver cancer by targeting persistent STAT3 signaling.

[Effects of raloxifene at two different doses for ovulation induction on endometrial pinopodes in mice during the implantation window]

OBJECTIVE

To compare the expression of pinopodes, the marker of endometrial receptivity, during the implantation window in Kunming mice stimulated with two different doses of raloxifene (RAL).

METHODS

Forty-eight 8-week-old female Kunming mice were randomly divided into 4 groups (n=12), namely saline group, clomiphene citrate (CC, 18 mg/kg) group, RAL (33 mg/kg) group and RAL (44 mg/kg group). In each group, the mice received intragastric administration of 1 mL of normal saline containing CC or RAL at the specified doses or saline only as indicated for ovulation induction, once daily for 2 days. The mice received then injection with 5 IU human chorionic gonadotropin (HCG) and mated and on day 4.5 of gestation, the pregnant mice were sacrificed for examination of the uterus with scanning electron microscopy.

RESULTS

Abundant and well developed pinopodes were observed in the endometrium of the mice in the 2 RAL groups and in the saline control group. The mice in CC group showed obviously reduced endometrial pinopodes with poor development.

CONCLUSIONS

RAL at two different doses does not obviously affect the expression of pinopodes in the uterine epithelium of mice, suggesting the safety of RAL at these two doses for ovulation induction without causing adverse effects on endometrial receptivity.

Nitrite-Mediated Hypoxic Vasodilation Predicted from Mathematical Modeling and Quantified from in Vivo Studies in Rat Mesentery

Nitric oxide (NO) generated from nitrite through nitrite reductase activity in red blood cells has been proposed to play a major role in hypoxic vasodilation. However, we have previously predicted from mathematical modeling that much more NO can be derived from tissue nitrite reductase activity than from red blood cell nitrite reductase activity. Evidence in the literature suggests that tissue nitrite reductase activity is associated with xanthine oxidoreductase (XOR) and/or aldehyde oxidoreductase (AOR). We investigated the role of XOR and AOR in nitrite-mediated vasodilation from computer simulations and from in vivo exteriorized rat mesentery experiments. Vasodilation responses to nitrite in the superfusion medium bathing the mesentery equilibrated with 5% O₂ (normoxia) or zero O₂ (hypoxia) at either normal or acidic pH were quantified. Experiments were also conducted following intraperitoneal (IP) injection of nitrite before and after inhibiting XOR with allopurinol or inhibiting AOR with raloxifene. Computer simulations for NO and O₂ transport using reaction parameters reported in the literature were also conducted to predict nitrite-dependent NO production from XOR and AOR activity as a function of nitrite concentration, PO₂ and pH. Experimentally, the largest arteriolar responses were found with nitrite >10 mM in the superfusate, but no statistically significant differences were found with hypoxic and acidic conditions in the superfusate. Nitrite-mediated vasodilation with IP nitrite injections was reduced or abolished after inhibiting XOR with allopurinol (p < 0.001). Responses to IP nitrite before and after inhibiting AOR with raloxifene were not as consistent. Our mathematical model predicts that under certain conditions, XOR and AOR nitrite reductase activity in tissue can significantly elevate smooth muscle cell NO and can serve as a compensatory pathway when endothelial NO production is limited by hypoxic conditions. Our theoretical and experimental results provide further evidence for a role of tissue nitrite reductases to contribute additional NO to compensate for reduced NO production by endothelial nitric oxide synthase during hypoxia. Our mathematical model demonstrates that under extreme hypoxic conditions with acidic pH, endogenous nitrite levels alone can be sufficient for a functionally significant increase in NO bioavailability. However, these conditions are difficult to achieve experimentally.

Identification of a Raloxifene Analog That Promotes AhR-Mediated Apoptosis in Cancer Cells

We previously reported that raloxifene, an estrogen receptor modulator, is also a ligand for the aryl hydrocarbon receptor (AhR). Raloxifene induces apoptosis in estrogen receptor-negative human cancer cells through the AhR. We performed structure–activity studies with seven raloxifene analogs to better understand the structural requirements of raloxifene for induction of AhR-mediated transcriptional activity and apoptosis. We identified Y134 as a raloxifene analog that activates AhR-mediated transcriptional activity and induces apoptosis in MDA-MB-231 human triple negative breast cancer cells. Suppression of AhR expression strongly reduced apoptosis induced by Y134, indicating the requirement of AhR for Y134-induced apoptosis. Y134 also induced apoptosis in hepatoma cells without having an effect on cell cycle regulation. Toxicity testing on zebrafish embryos revealed that Y134 has a significantly better safety profile than raloxifene. Our studies also identified an analog of raloxifene that acts as a partial antagonist of the AhR, and is capable of inhibiting AhR agonist-induced transcriptional activity. We conclude that Y134 is a promising raloxifene analog for further optimization as an anti-cancer agent targeting the AhR.

Effects of minodronate in postmenopausal women with osteoporosis who received prior treatment with raloxifene

Background

In clinical practice, patients with postmenopausal osteoporosis have often shown a poor response to treatment with an antiresorptive agent for several years. The purpose of this study was to investigate the efficacy of switching raloxifene with minodronate in patients who responded poorly to the treatment of postmenopausal osteoporosis with raloxifene.

Patients and methods

This observational study was conducted based on a single-arm, non-randomized, open-label design and was approved by the institute’s institutional review board. Postmenopausal women with osteoporosis who became unresponsive in terms of bone mineral density (BMD) after being administered raloxifene for two or more years were enrolled. Patients were treated with 1 mg minodronate daily or 50 mg minodronate monthly. Changes in BMD and serum bone turnover markers were monitored at baseline, 6, 12, and 24 months after switching treatment.

Results

Twenty-seven patients were enrolled. Two discontinued treatment because of adverse events related to the study drug. Among the remaining 25 patients, lumbar BMD significantly increased by 3.67%, 5.08%, and 6.97% at 6, 12, and 24 months, respectively, and femoral neck BMD increased by 1.63%, 2.18%, and 3.85% at 6, 12, and 24 months, respectively. Serum bone-specific alkaline phosphatase showed a significant reduction of 30.35% from the baseline (p<0.0001) within the first 6 months, suggesting a stronger antiresorptive effect of minodronate. Serum N-terminal telopeptide of type I collagen showed a tendency to decrease.

Conclusion

Switching raloxifene with minodronate is effective in poor responders of osteoporosis treatment and should be considered as one of the treatment options for osteoporosis.

Enhanced cytotoxicity and apoptosis by raloxifene in combination with estrogen and methotrexate in human endometrial stromal cells

Endometrial hyperplasia is a condition that may lead to the development of endometrial carcinoma. Initially, changes of the endometrium are caused by the estrogen's hyperstimulation that may lead to the development of an irregular bleeding and the infertility problems. Therapy of endometrial hyperplasia is limited to medical and surgical approaches. During the past decade, the new types of drugs were developed for the treatment of the endometrial hyperplasia. Here, for the first time, we investigated the cytotoxic effects of the various combinations of estrogen, raloxifene, and methotrexate in human ThESC cell line as a possible potential treatment of the endometrial hyperplasia. Our aim was to investigate and to determine the most efficient combination of investigated drugs in ThESC cells during 24-hr period using MTT assay, FACS analysis, and immunofluorescence staining. Our results demonstrated that the combination of raloxifene with methotrexate efficiently induced both the cytotoxicity and apoptosis in ThESC cells when compared to their single effect, as well as to the effect of combined treatment of raloxifene with estrogen. The application of the low doses of methotrexate combined with raloxifene offers all advantages of a potential beneficial antitumor match in cancer chemoprevention and therapy.

Controlling Sulfuryl-Transfer Biology

In humans, the cytosolic sulfotransferases (SULTs) catalyze regiospecific transfer of the sulfuryl moiety (-SO3) from 3'-phosphoadenosine 5'-phosphosulfate to thousands of metabolites, including numerous signaling small molecules, and thus regulates their activities and half-lives. Imbalances in the in vivo set points of these reactions leads to disease. Here, with the goal of controlling sulfonation in vivo, molecular ligand-recognition principles in the SULT and nuclear receptor families are integrated in creating a strategy that can prevent sulfonation of a compound without significantly altering its receptor affinity, or inhibiting SULTS. The strategy is validated by using it to control the sulfonation and estrogen receptor (ER) activating activity of raloxifene (a US Food and Drug Administration-approved selective estrogen receptor modulator) and its derivatives. Preventing sulfonation is shown to enhance ER-activation efficacy 10(4)-fold in studies using Ishikawa cells. The strategy offers the opportunity to control sulfuryl transfer on a compound-by-compound basis, to enhance the efficacy of sulfonated drugs, and to explore the biology of sulfuryl transfer with unprecedented precision.

Evidence that fetal death is associated with placental aging

BACKGROUND

The risk of unexplained fetal death or stillbirth increases late in pregnancy, suggesting that placental aging is an etiological factor. Aging is associated with oxidative damage to DNA, RNA, and lipids. We hypothesized that placentas at >41 completed weeks of gestation (late-term) would show changes consistent with aging that would also be present in placentas associated with stillbirths.

OBJECTIVE

We sought to determine whether placentas from late-term pregnancies and unexplained stillbirth show oxidative damage and other biochemical signs of aging. We also aimed to develop an in vitro term placental explant culture model to test the aging pathways.

STUDY DESIGN

We collected placentas from women at 37-39 weeks' gestation (early-term and term), late-term, and with unexplained stillbirth. We used immunohistochemistry to compare the 3 groups for: DNA/RNA oxidation (8-hydroxy-deoxyguanosine), lysosomal distribution (lysosome-associated membrane protein 2), lipid oxidation (4-hydroxynonenal), and autophagosome size (microtubule-associated proteins 1A/1B light chain 3B, LC3B). The expression of aldehyde oxidase 1 was measured by real-time polymerase chain reaction. Using a placental explant culture model, we tested the hypothesis that aldehyde oxidase 1 mediates oxidative damage to lipids in the placenta.

RESULTS

Placentas from late-term pregnancies show increased aldehyde oxidase 1 expression, oxidation of DNA/RNA and lipid, perinuclear location of lysosomes, and larger autophagosomes compared to placentas from women delivered at 37-39 weeks. Stillbirth-associated placentas showed similar changes in oxidation of DNA/RNA and lipid, lysosomal location, and autophagosome size to placentas from late-term. Placental explants from term deliveries cultured in serum-free medium also showed evidence of oxidation of lipid, perinuclear lysosomes, and larger autophagosomes, changes that were blocked by the G-protein-coupled estrogen receptor 1 agonist G1, while the oxidation of lipid was blocked by the aldehyde oxidase 1 inhibitor raloxifene.

CONCLUSION

Our data are consistent with a role for aldehyde oxidase 1 and G-protein-coupled estrogen receptor 1 in mediating aging of the placenta that may contribute to stillbirth. The placenta is a tractable model of aging in human tissue.

Semantic Memory in the Clinical Progression of Alzheimer Disease

BACKGROUND AND OBJECTIVE

Semantic memory measures may be useful in tracking and predicting progression of Alzheimer disease. We investigated relationships among semantic memory tasks and their 1-year predictive value in women with Alzheimer disease.

METHODS

We conducted secondary analyses of a randomized clinical trial of raloxifene in 42 women with late-onset mild-to-moderate Alzheimer disease. We assessed semantic memory with tests of oral confrontation naming, category fluency, semantic recognition and semantic naming, and semantic density in written narrative discourse. We measured global cognition (Alzheimer Disease Assessment Scale, cognitive subscale), dementia severity (Clinical Dementia Rating sum of boxes), and daily function (Activities of Daily Living Inventory) at baseline and 1 year.

RESULTS

At baseline and 1 year, most semantic memory scores correlated highly or moderately with each other and with global cognition, dementia severity, and daily function. Semantic memory task performance at 1 year had worsened one-third to one-half standard deviation. Factor analysis of baseline test scores distinguished processes in semantic and lexical retrieval (semantic recognition, semantic naming, confrontation naming) from processes in lexical search (semantic density, category fluency). The semantic-lexical retrieval factor predicted global cognition at 1 year. Considered separately, baseline confrontation naming and category fluency predicted dementia severity, while semantic recognition and a composite of semantic recognition and semantic naming predicted global cognition. No individual semantic memory test predicted daily function.

CONCLUSIONS

Semantic-lexical retrieval and lexical search may represent distinct aspects of semantic memory. Semantic memory processes are sensitive to cognitive decline and dementia severity in Alzheimer disease.

Induction of mitochondrial apoptotic pathway by raloxifene and estrogen in human endometrial stromal ThESC cell line

INTRODUCTION

Endometrial hyperplasia is a condition that occurs as a result of hormonal imbalance between estrogen and progesterone. Morphological disturbance of endometrial cells occurs consequently leading towards endometrial cancer. In therapy of endometrial hyperplasia SERMs are used to supress effects of locally high estrogen level in uterus. There is strong evidence suggesting that estrogen could be involved in cell death - apoptosis. There are no experimental data demstrating the direct apoptotic effect of both raloxifene and estrogen on the ThESC cell line. The aim of our study wa sto investigate both cytotoxic and apototic mechanism of raloxifene and estrogen - induced death in the ThESC cell line.

MATERIAL AND METHODS

In order to determine their cytotoxic and apoptotic effects, various doses of raloxifene and estrogen were applied to the ThESC cell line for 24 h. After the treatment MTT assay, FACS analysis and immunofluoroscence method were conducted.

RESULTS

The results of this study for the first time demonstrated the cytotoxic and apoptotic effects of raloxifene and estrogen on human endometrial stromal cell line suggesting the involvement of the inner, mitochondrial apoptotic pathway.

CONCLUSIONS

Our results demonstrated apoptotic effects of investigated drugs in the ThESC cell line through increasing the Bax/Bcl-2 ratio and activation of caspase 3.

Effects of estrogen receptor modulators on cytoskeletal proteins in the central nervous system

Estrogen receptor modulators are compounds of interest because of their estrogenic agonistic/antagonistic effects and tissue specificity. These compounds have many clinical applications, particularly for breast cancer treatment and osteoporosis in postmenopausal women, as well as for the treatment of climacteric symptoms. Similar to estrogens, neuroprotective effects of estrogen receptor modulators have been described in different models. However, the mechanisms of action of these compounds in the central nervous system have not been fully described. We conducted a systematic search to investigate the effects of estrogen receptor modulators in the central nervous system, focusing on the modulation of cytoskeletal proteins. We found that raloxifene, tamoxifen, and tibolone modulate some cytoskeletal proteins such as tau, microtuble-associated protein 1 (MAP1), MAP2, neurofilament 38 (NF38) by different mechanisms of action and at different levels: neuronal microfilaments, intermediate filaments, and microtubule-associated proteins. Finally, we emphasize the importance of the study of these compounds in the treatment of neurodegenerative diseases since they present the benefits of estrogens without their side effects.

Variability of Zaleplon 5-Oxidase Activity in Mice and Humans, and Inhibition by Raloxifene

BACKGROUND

Zaleplon (ZAL) is a sedative-hypnotic agent, which is mainly metabolized to inactive 5-oxidized zaleplon (5-oxo-ZAL) and N-des-ethylated ZAL (des-ethyl-ZAL) in mice and humans. The former reaction is considered to be catalyzed by aldehyde oxidase present in liver cytosol.

METHODS

Here, we examined sex and strain differences of ZAL metabolism to 5-oxo-ZAL among four strains of mice, as well as the inter-individual variation in humans, in order to evaluate the variability of 5-oxo-ZAL-forming activity and its relationship with aldehyde oxidase activity. In mice, the activity in C57BL/6J strain was the highest, followed by C3H/He and BALB/c. The activity in DBA/2J was the lowest, being 2.3-fold lower than that of C57BL/6J mice. The activity of male mice was higher than that of female mice. Large inter-individual variations were observed among humans, with a range of 10- fold. Raloxifene, an inhibitor of aldehyde oxidase, markedly decreased the formation of 5-oxo-ZAL by liver cytosol of mice and humans. Further, the plasma level of 5-oxo-ZAL in mice was decreased when raloxifene was co-administered with ZAL.

RESULTS

Our results indicate that the formation of 5-oxo-ZAL from ZAL is mainly catalyzed by aldehyde oxidase in mice and humans, and the variability of 5-oxo-ZAL formation is due primarily to differences of aldehyde oxidase activity.

CONCLUSION

High inter-individual variability of ZAL 5-oxidase activity and potential for interaction of ZAL with other medicines that are inhibitors of aldehyde oxidase should be taken into consideration in clinical usage of ZAL.

The Selective Estrogen Receptor Modulator Raloxifene Inhibits Neutrophil Extracellular Trap Formation

Raloxifene is a selective estrogen receptor modulator typically prescribed for the prevention/treatment of osteoporosis in postmenopausal women. Although raloxifene is known to have anti-inflammatory properties, its effects on human neutrophils, the primary phagocytic leukocytes of the immune system, remain poorly understood. Here, through a screen of pharmacologically active small molecules, we find that raloxifene prevents neutrophil cell death in response to the classical activator phorbol 12-myristate 13-acetate (PMA), a compound known to induce formation of DNA-based neutrophil extracellular traps (NETs). Inhibition of PMA-induced NET production by raloxifene was confirmed using quantitative and imaging-based assays. Human neutrophils from both male and female donors express the nuclear estrogen receptors ERα and ERβ, known targets of raloxifene. Similar to raloxifene, selective antagonists of these receptors inhibit PMA-induced NET production. Furthermore, raloxifene inhibited PMA-induced ERK phosphorylation, but not reactive oxygen species production, pathways known to be key modulators of NET production. Finally, we found that raloxifene inhibited PMA-induced, NET-based killing of the leading human bacterial pathogen, methicillin-resistant Staphylococcus aureus. Our results reveal that raloxifene is a potent modulator of neutrophil function and NET production.

Reversal effects of Raloxifene on paclitaxel resistance in 2 MDR breast cancer cells

Raloxifene hydrochloride (RAL), one of second generation of selective estrogen receptor modulators (SERMs), is usually used in preventing osteoporosis and breast cancer. The present study evaluated whether Raloxifene might sensitize multidrug resistant (MDR) breast cancers to chemotherapies, especially in estrogen receptor negative (ER-) breast cancer. The results showed that RAL could significantly sensitize ER- MDR breast tumors to paclitaxel both in vitro and in vivo. Combination of Raloxifene could significantly enhance paclitaxel-induced cell apoptosis, G2-M arrest as well as inhibition of cell proliferation in MDR tumors. Further studies showed that the combined treatment did not alter P-glycoprotein expression but increased P-gp ATPase activity. These results suggested that raloxifene might be a valuable chemosensitizer agent for breast cancer therapy.

The Effectiveness of Raloxifene-Loaded Liposomes and Cochleates in Breast Cancer Therapy

Liposome (spherical vesicles) and cochleate (multilayer crystalline, spiral structure) formulations containing raloxifene have been developed having dimethyl-β-cyclodextrin (DM-β-CD) or sodium taurocholate (NaTC). Raloxifene was approved initially for the treatment of osteoporosis but it is also effective on breast tissue and endometrial cells. Raloxifene inhibits matrix metalloproteinase-2 (MMP-2) enzyme, which is known to be responsible for tumor invasion and the initiation of angiogenesis during the tumor growth. Therefore, raloxifene was selected as a model drug. A series of raloxifene-loaded liposome and cochleate formulations were prepared. In vitro release studies and in vivo tests were performed. Breast cancer cell lines (MCF-7) were also used to find the most effective formulation. Highest antitumor activity was observed, and MMP-2 enzyme was also found to be inhibited with raloxifene-loaded cochleates containing DM-β-CD. These developed formulations can be helpful for further treatment alternatives and new strategies for cancer therapy.

Affective forecasting and medication decision making in breast-cancer prevention

OBJECTIVE

Over 2 million American women at elevated risk for breast cancer are eligible to take chemoprevention medications such as tamoxifen and raloxifene, which can cut in half the risk of developing breast cancer, but which also have a number of side effects. Historically, very few at-risk women have opted to use chemoprevention medications. Affective forecasting theory suggests that people may avoid these medications if they expect taking them to increase their health-related stress.

METHOD

After receiving an individually tailored decision aid that provided personalized information about the risks and benefits of these medications, 661 women at elevated risk of breast cancer were asked to make 3 affective forecasts, predicting what their level of health-related stress would be if they took tamoxifen, raloxifene, or neither medication. They also completed measures of decisional preferences and intentions, and at a 3-month follow-up, reported on whether or not they had decided to use either medication.

RESULTS

On the affective forecasting items, very few women (<10%) expected the medications to reduce their health-related stress, relative to no medication at all. Participants with more negative affective forecasts about taking a chemoprevention medication expressed lower preferences and intentions for using the medications (Cohen's ds from 0.74 to 0.79) and were more likely to have opted against using medication at follow-up (OR range = 1.34-2.66).

CONCLUSION

These findings suggest that affective forecasting may explain avoidance of breast-cancer chemoprevention medications. They also highlight the need for more research aimed at integrating emotional content into decision aids. (PsycINFO Database Record

Evaluation of Ki-67 antigen expression in the vaginal epithelium of castrated female rats treated with raloxifene and tamoxifen: a comparative study

OBJECTIVE

The aim of this study was to evaluate the effects of raloxifene and tamoxifen on Ki-67 antigen expression in the vaginal epithelium of castrated rats.

MATERIAL AND METHODS

Thirty-nine virgin, adult, castrated female Wistar-Hannover rats were randomly divided into three groups: Group I (control, n = 13), Group II (raloxifene, n  = 13) and Group III (tamoxifen, n = 13). After confirmation of their hypoestrogenic state, the rats were given 0.5 ml of propylene glycol (vehicle), 750 μg of raloxifene or 250 μg of tamoxifen, respectively, by gavage, for 30 days. On the 31st day, the rats were euthanized and their vaginas removed and fixed in 10% buffered formalin for of Ki-67 immunohistochemical evaluation. Data were analyzed using Levene's test and Tukey's method (p < 0.05).

RESULTS

Mean Ki-67 expression in groups I, II and III was 27 ± 2.6, 32.3 ± 1.9 and 43.7 ± 3.5, respectively. In Group III (tamoxifen), there was a greater proportion of stained cells compared to Groups I and II (p < 0.0003), with no statistically significant difference between Groups I and II (p = 0.3626).

CONCLUSIONS

The present results show that tamoxifen significantly increased cell proliferation in the vaginal epithelium of the castrated rats and no difference between the raloxifene and control groups.

Comparison of the effects of eldecalcitol with either raloxifene or bisphosphonate on serum tartrate resistant acid phosphatase-5b, a bone resorption marker, in postmenopausal osteoporosis

OBJECTIVE

This study analyzes whether concomitant raloxifene (RLX) or bisphosphonates (BP) plus eldecalcitol (ELD) has excessive suppressive effects on a bone resorption marker during the first 6 months of treatment in postmenopausal women in real-world setting.

METHODS

285 postmenopausal osteoporotic patients who had been treated with RLX or BP plus ELD were evaluated the bone resorption marker, serum tartrate resistant acid phosphatase-5b (TRACP-5b), during the first 6 months of treatment.

RESULTS

In drug-naïve group (not received osteoporosis medications before the administration, n=70), the concomitant RLX or BP with ELD significantly decreased levels of TRACP-5b without severe suppression. In vitamin D switch group [RLX or BP plus alfacalcidol (ALF) and then switched to RLX or BP plus ELD, n=215], the replacing ALF with ELD further and significantly decreased TRACP-5b and tertile analyses based on baseline values were significantly decreased far more in the highest, compared with the lowest tertile in the ELD+RLX and ELD+BP groups.

CONCLUSION

ELD combined with RLX or BP administered for 6 months to postmenopausal women with osteoporosis who were drug-naïve or who had switched medications significantly reduced and maintained TRACP-5b values within the reference range.

Relationship Between Breast Density and Selective Estrogen-Receptor Modulators, Aromatase Inhibitors, Physical Activity, and Diet: A Systematic Review

Background Lower breast density (BD) is associated with lower risk of breast cancer and may serve as a biomarker for the efficacy of chemopreventive strategies. This review explores parameters that are thought to be associated with lower BD. We conducted a systematic review of articles published to date using the PRISMA strategy. Articles that assessed change in BD with estrogen-receptor modulators (tamoxifene [TAM], raloxifene [RLX], and tibolone) and aromatase inhibitors (AIs), as well as cross-sectional and longitudinal studies (LSs) that assessed association between BD and physical activity (PA) or diet were reviewed. Results Ten studies assessed change in BD with TAM; all reported TAM-mediated BD decreases. Change in BD with RLX was assessed by 11 studies; 3 reported a reduction in BD. Effect of tibolone was assessed by 5 RCTs; only 1 reported change in BD. AI-mediated BD reduction was reported by 3 out of 10 studies. The association between PA and BD was assessed by 21 studies; 4 reported an inverse association. The relationship between diet and BD was assessed in 34 studies. All studies on calcium and vitamin D as well as vegetable intake reported an inverse association with BD in premenopausal women. Two RCTs demonstrated BD reduction with a low-fat, high-carbohydrate intervention. Conclusion TAM induces BD reduction; however, the effect of RLX, tibolone, and AIs on BD is unclear. Although data on association between diet and BD in adulthood are contradictory, intake of vegetables, vitamin D, and calcium appear to be associated with lower BD in premenopausal women.

Raloxifene improves skeletal properties in an animal model of cystic chronic kidney disease

Patients with chronic kidney disease (CKD) have an increased risk of fracture. Raloxifene is a mild antiresorptive agent that reduces fracture risk in the general population. Here we assessed the impact of raloxifene on the skeletal properties of animals with progressive CKD. Male Cy/+ rats that develop autosomal dominant cystic kidney disease were treated with either vehicle or raloxifene for five weeks. They were assessed for changes in mineral metabolism and skeletal parameters (microCT, histology, whole-bone mechanics, and material properties). Their normal littermates served as controls. Animals with CKD had significantly higher parathyroid hormone levels compared with normal controls, as well as inferior structural and mechanical skeletal properties. Raloxifene treatment resulted in lower bone remodeling rates and higher cancellous bone volume in the rats with CKD. Although it had little effect on cortical bone geometry, it resulted in higher energy to fracture and modulus of toughness values than vehicle-treated rats with CKD, achieving levels equivalent to normal controls. Animals treated with raloxifene had superior tissue-level mechanical properties as assessed by nanoindentation, and higher collagen D-periodic spacing as assessed by atomic force microscopy. Thus, raloxifene can positively impact whole-bone mechanical properties in CKD through its impact on skeletal material properties.

Endometrial Receptivity Markers in Mice Stimulated With Raloxifene Versus Clomiphene Citrate and Natural Cycles

Ovulation induction therapy with clomiphene citrate can suppress endometrial receptivity. Raloxifene may be an alternative therapeutic for women with ovulatory disorders. This study aimed to compare the expression of endometrial receptivity markers, including homeobox gene 10 (HOXA10), integrin β3, and leukemia inhibitory factor (LIF), as well as pinopode production during the implantation window in mice stimulated with raloxifene and clomiphene citrate and natural cycles. Thirty-six 8-week-old female Kunming mice were randomly divided into 3 groups (n = 12) and administered daily raloxifene (22 mg/kg), clomiphene citrate (18 mg/kg), and normal saline (1 mL), respectively, by gavage. Two days later, mice were injected with 5 IU human chorionic gonadotropin and mated. Successfully mated female animals were identified with vaginal plugs designated gestation day 1. At day 4.5, pregnant donor mice were euthanized, and uterus samples were collected for immunohistochemistry, quantitative polymerase chain reaction, Western blot, and scanning electron microscopy analyses. Homeobox gene 10, integrin β3, and LIF messenger RNA (mRNA) and protein levels were significantly higher in the raloxifene-treated animals compared with the clomiphene citrate group (all P < .05) but not significantly different from saline group values, except for LIF and integrin β3 mRNA levels (P < .05). Pinopodes were abundant and well developed in the raloxifene and saline groups; however, in the clomiphene citrate-treated mice, fewer and poorly developed pinopodes were obtained. In mice, raloxifene had no effect on HOXA10, integrin β3, and LIF expression as well as pinopode production, suggesting it has no adverse effects on endometrial receptivity. Raloxifene may provide a viable alternative oral ovulation induction agent to clomiphene citrate.