Fibroblast stromal support model for predicting human papillomavirus-associated cancer drug responses.

Currently, there are no specific antiviral therapeutic approaches targeting Human papillomaviruses (HPVs), which cause around 5% of all human cancers. Specific antiviral reagents are particularly needed for HPV-related oropharyngeal cancers (HPV+OPCs) whose incidence is increasing and for which there are no early diagnostic tools available. We and others have demonstrated that the estrogen receptor alpha (ERα) is overexpressed in HPV+OPCs, compared to HPV-negative cancers in this region, and that these elevated levels are associated with an improved disease outcome. Utilizing this HPV+-specific overexpression profile, we previously demonstrated that estrogen attenuates the growth and cell viability of HPV+ keratinocytes and HPV+ cancer cells in vitro. Expansion of this work in vivo failed to replicate this sensitization. The role of stromal support from the tumor microenvironment (TME) has previously been tied to both the HPV lifecycle and in vivo therapeutic responses. Our investigations revealed that in vitro co-culture with fibroblasts attenuated HPV+-specific estrogen growth responses. Continuing to monopolize on the HPV+-specific overexpression of ERα, our co-culture models then assessed the suitability of the selective estrogen receptor modulators (SERMs), raloxifene and tamoxifen, and showed growth attenuation in a variety of our models to one or both of these drugs in vitro. Utilization of these SERMs in vivo closely resembled the sensitization predicted by our co-culture models. Therefore, the in vitro fibroblast co-culture model better predicts in vivo responses. We propose that utilization of our co-culture in vitro model can accelerate cancer therapeutic drug discovery. IMPORTANCE: Human papillomavirus-related cancers (HPV+ cancers) remain a significant public health concern, and specific clinical approaches are desperately needed. In translating drug response data from in vitro to in vivo, the fibroblasts of the adjacent stromal support network play a key role. Our study presents the utilization of a fibroblast 2D co-culture system to better predict translational drug assessments for HPV+ cancers. We also suggest that this co-culture system should be considered for other translational approaches. Predicting even a portion of treatment paradigms that may fail in vivo with a co-culture model will yield significant time, effort, resource, and cost efficiencies.

The comparison of alendronate and raloxifene after denosumab (CARD) study: A comparative efficacy trial.

Denosumab discontinuation results in accelerated bone remodeling, decreased bone mineral density (BMD), and an increased risk of multiple vertebral fractures. Bisphosphonates are at least partially effective at inhibiting these consequences but there have been no randomized clinical trials assessing the efficacy of alternative antiresorptives. PURPOSE: The aim of this study was to evaluate the comparative efficacy of alendronate and the SERM, raloxifene, in preventing the post-denosumab high-turnover bone loss. METHODS: We conducted an open-label randomized controlled trial in which 51 postmenopausal women at increased risk of fracture were randomized with equal probability to receive 12-months of denosumab 60-mg 6-monthly followed by 12-months of either alendronate 70-mg weekly or raloxifene 60-mg daily. Serum bone remodeling markers were measured at 0,6,12,15,18, and 24 and areal BMD of the distal radius, spine, and hip were measured at 0,12,18 and 24 months. RESULTS: After denosumab discontinuation, serum markers of bone remodeling remained suppressed when followed by alendronate, but gradually increased to baseline when followed by raloxifene. In the denosumab-to-alendronate group, denosumab-induced BMD gains were maintained at all sites whereas in the denosumab-to-raloxifene group, BMD decreased at the spine by 2.0% (95% CI -3.2 to -0.8, P = 0.003) and at the total hip by 1.2% (-2.1 to -0.4%, P = 0.008), but remained stable at the femoral neck and distal radius and above the original baseline at all sites. The decreases in spine and total hip BMD in the denosumab-to-raloxifene group (but not the femoral neck or distal radius) were significant when compared to the denosumab-to-alendronate group. CONCLUSIONS: These results suggest that after one year of denosumab, one year of alendronate is better able to maintain the inhibition of bone remodeling and BMD gains than raloxifene.

Maternal immune activation and estrogen receptor modulation induce sex-specific dopamine-related behavioural and molecular alterations in adult rat offspring.

Dopamine dysregulation contributes to psychosis and cognitive deficits in schizophrenia that can be modelled in rodents by inducing maternal immune activation (MIA). The selective estrogen receptor (ER) modulator, raloxifene, can improve psychosis and cognition in men and women with schizophrenia. However, few studies have examined how raloxifene may exert its therapeutic effects in mammalian brain in both sexes during young adulthood (age relevant to most prevalent age at diagnosis). Here, we tested the extent to which raloxifene alters dopamine-related behaviours and brain transcripts in young adult rats, both control and MIA-exposed females and males. We found that raloxifene increased amphetamine (AMPH)-induced locomotor activity in female controls, and in contrast, raloxifene reduced AMPH-induced locomotor activity in male MIA offspring. We did not detect overt prepulse inhibition (PPI) deficits in female or male MIA offspring, yet raloxifene enhanced PPI in male MIA offspring. Whereas, raloxifene ameliorated increased startle responsivity in female MIA offspring. In the substantia nigra (SN), we found reduced Drd2s mRNA in raloxifene-treated female offspring with or without MIA, and increased Comt mRNA in placebo-treated male MIA offspring relative to placebo-treated controls. These data demonstrate an underlying dopamine dysregulation in MIA animals that can become more apparent with raloxifene treatment, and may involve selective alterations in dopamine receptor levels and dopamine breakdown processes in the SN. Our findings support sex-specific, differential behavioural responses to ER modulation in MIA compared to control offspring, with beneficial effects of raloxifene treatment on dopamine-related behaviours relevant to schizophrenia found in male MIA offspring only.

Unveiling the potential of estrogen: Exploring its role in neuropsychiatric disorders and exercise intervention.

Neuropsychiatric disorders shorten human life spans through multiple ways and become major threats to human health. Exercise can regulate the estrogen signaling, which may be involved in depression, Alzheimer's disease (AD) and Parkinson's disease (PD), and other neuropsychiatric disorders as well in their sex differences. In nervous system, estrogen is an important regulator of cell development, synaptic development, and brain connectivity. Therefore, this review aimed to investigate the potential of estrogen system in the exercise intervention of neuropsychiatric disorders to better understand the exercise in neuropsychiatric disorders and its sex specific. Exercise can exert a protective effect in neuropsychiatric disorders through regulating the expression of estrogen and estrogen receptors, which are involved in neuroprotection, neurodevelopment, and neuronal glucose homeostasis. These processes are mediated by the downstream factors of estrogen signaling, including N-myc downstream regulatory gene 2 (Ndrg2), serotonin (5-HT), delta like canonical Notch ligand 1 (DLL1), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), etc. In addition, exercise can act on the estrogen response element (ERE) fragment in the genes of estrogenic downstream factors like ß-amyloid precursor protein cleavase 1 (BACE1). However, there are few studies on the relationship between exercise, the estrogen signaling pathway, and neuropsychiatric disorders. Hence, we review how the estrogen signaling mediates the mechanism of exercise intervention in neuropsychiatric disorders. We aim to provide a theoretical perspective for neuropsychiatric disorders affecting female health and provide theoretical support for the design of exercise prescriptions.

The effect of raloxifene supplementation on blood pressure and Apo-lipoproteins in postmenopausal women: A systematic review and meta-analysis.

INTRODUCTION: Several studies indicated the ameliorating effects of raloxifene supplementation on apolipoproteins and blood pressure, although others have conflicting findings. Therefore, the present study was conducted in order to accurately and definitively understands the effect of raloxifene on apolipoprotein AI (Apo-AI), apolipoprotein B (APoB), lipoprotein (a) (Lp (a)), systolic blood pressure (SBP) and diastolic blood pressure (DBP) in postmenopausal women. METHODS: A systematic literature search was conducted using scientific databases including PubMed, Scopus, Embase, and Web of Science and the Cochrane Library, through May 2024. The quality of studies was assessed using Cochrane tool. Random-effects meta-analysis was used to pool standardized mean differences (SMD) and 95 % CI for the outcomes. RESULTS: Twenty trials, with interventions ranging from 6 to 144 weeks and 2825 participants, were included. Raloxifene supplementation demonstrated significant reductions in ApoB (SMD: -0.92; 95 % CI: -1.49 to -0.35; P = 0.001), and Lp (a) (SMD: -0.25; 95 % CI: -0.39 to -0.11; P < 0.001) while increasing Apo-AI levels (SMD: 0.29; 95 % CI: 0.22-0.36; P < 0.001). Conversely, no significant effects were observed on SBP (WMD: -0.49 mmHg; 95 % CI: -3.01-2.04; P = 0.706), and DBP (WMD: -0.81 mmHg; 95 % CI: -4.04-2.41; P = 0.621). Moreover, subgroup analysis indicated that raloxifene significantly decreased DBP in studies with intervention durations of >12 weeks. CONCLUSIONS: This meta-analysis has shown that raloxifene supplementation may have beneficial effects on apolipoproteins in postmenopausal women. Future studies are needed to investigate the effect of raloxifene on health status in in postmenopausal women.

Synthesis, biological evaluation, and stability studies of raloxifene mono- and bis-sulfamates as dual-targeting agents.

All three possible sulfamate derivatives of the selective estrogen receptor modulator Raloxifene (bis-sulfamate 7 and two mono-sulfamates 8-9) were synthesized and evaluated as inhibitors of the clinical drug target steroid sulfatase (STS), both in cell-free and in cell-based assays, and also as estrogen receptor (ER) modulators. Bis-sulfamate 7 was the most potent STS inhibitor with an IC50 of 12.2 nM in a whole JEG3 cell-based assay, with the two mono-sulfamates significantly weaker. The estrogen receptor-modulating activities of 7-9 showed generally lower affinities compared to Raloxifene HCl, diethylstilbestrol and other known ligands, with mono-sulfamate 8 being the best ligand (Ki of 1.5 nM) for ERα binding, although 7 had a Ki of 13 nM and both showed desirable antagonist activity. The antiproliferative activities of the sulfamate derivatives against the T-47D breast cancer cell line showed 7 as most potent (GI50 = 7.12 µM), comparable to that of Raloxifene. Compound 7 also showed good antiproliferative potency in the NCI-60 cell line panel with a GI50 of 1.34 µM against MDA-MB-231 breast cancer cells. Stability testing of 7-9 showed that bis-sulfamate 7 hydrolyzed by desulfamoylation at a surprisingly rapid rate, initially leading selectively to 8 and finally to Raloxifene 3 without formation of 9. The mechanisms of these hydrolysis reactions could be extensively rationalized. Conversion of Raloxifene (3) into its bis-sulfamate (7) thus produced a promising drug lead with nanomolar dual activity as an STS inhibitor and ERα antagonist, as a potential candidate for treatment of estrogen-dependent breast cancer.

27-Hydroxycholesterol contributes to hypercholesterolemia-associated aggravation of apical periodontitis in ovariectomized rats and raloxifene counteracts its action.

AIM: The influence of hypercholesterolemia on the development of apical periodontitis (AP) is inconclusive. Recent studies revealed that cholesterol metabolite 27-hydoxycholesterol (27HC) can affect cellular responses to bacterial infections and oestrogen status and raloxifene may influence its action. Herein, we aimed to examine the impact of 27HC on production of inflammatory mediators by macrophages and the regulatory function of raloxifene. The contribution of 27HC to AP development and the therapeutic effect of raloxifene were evaluated in a rat model. METHODS: Murine macrophages J774 cells were used. The expression of inducible nitric oxide synthase (iNOS) was examined by Western blot. The concentrations of C-C motif chemokine ligand (CCL) 2 and 27HC were assessed by enzyme-linked immunosorbent assay. Colorimetric assay was used to evaluate cholesterol levels. Experimental AP was induced in ovariectomized (OVX) or un-operated rats receiving high-fat/high-cholesterol diet (HFHCD) or normal diet (ND). Micro-computed tomography and immunohistochemistry were employed to evaluate disease severity and the therapeutic effect of raloxifene. RESULTS: Cholesterol enhanced 27HC production in macrophages. 27HC induced iNOS and CCL2 synthesis by macrophages and estradiol suppressed the responses. In our animal model of AP, HFHCD plus OVX significantly augmented serum and lesion tissue levels of 27HC (p < .05 versus the ND group). Lesion size, infiltration of CD68+ cells, and iNOS+ monocytes were increased in parallel with 27HC accumulation. Raloxifene inhibited pro-inflammatory effects of 27HC on macrophages and suppressed AP progression in HFHCD/OVX rats (p < .05 versus the vehicle control group). CONCLUSIONS: Our results suggested that 27HC contributes to AP aggravation associated with hypercholesterolemia. Oestrogen deficiency may both enhance 27HC production and exacerbate its downstream action.

The role of PKN1 in glioma pathogenesis and the antiglioma effect of raloxifene targeting PKN1.

PKN1 (protein kinase N1), a serine/threonine protein kinase family member, is associated with various cancers. However, the role of PKN1 in gliomas has rarely been studied. We suggest that PKN1 expression in glioma specimens is considerably upregulated and positively correlates with the histopathological grading of gliomas. Knocking down PKN1 expression in glioblastoma (GBM) cells inhibits GBM cell proliferation, invasion and migration and promotes apoptosis. In addition, yes-associated protein (YAP) expression, an essential effector of the Hippo pathway contributing to the oncogenic role of gliomagenesis, was also downregulated. In contrast, PKN1 upregulation enhances the malignant characteristics of GBM cells and simultaneously upregulates YAP expression. Therefore, PKN1 is a promising therapeutic target for gliomas. Raloxifene (Ralo), a commonly used selective oestrogen-receptor modulator to treat osteoporosis in postmenopausal women, was predicted to target PKN1 according to the bioinformatics team from the School of Mathematics, Tianjin Nankai University. We showed that Ralo effectively targets PKN1, inhibits GBM cells proliferation and migration and sensitizes GBM cells to the major chemotherapeutic drug, Temozolomide. Ralo also reverses the effect of PKN1 on YAP activation. Thus, we confirm that PKN1 contributes to the pathogenesis of gliomas and may be a potential target for Ralo adjuvant glioma therapy.

Cardioprotective effect of tamoxifen and raloxifene: Preventing proteoglycan synthesis by modulating non-canonical TGF-ß signalling through NADPH oxidase and ERK phosphorylation.

Atherosclerosis, a leading cause of cardiovascular disease, remains a significant global health concern. Tamoxifen and raloxifene, selective estrogen receptor modulators (SERMs), have demonstrated potential cardioprotective effects. However, the underlying molecular mechanisms by which these SERMs modulate Transforming Growth Factor-ß (TGF-ß) signaling in human vascular smooth muscle cells (VSMCs) remain largely unexplored. This study sought to investigate the impact of tamoxifen and raloxifene on TGF-ß-induced CHSY1 expression and Smad2 linker region phosphorylation in VSMCs and to elucidate the role of reactive oxygen species (ROS), NADPH oxidase (NOX), and kinase pathways in mediating these effects. Employing a comprehensive experimental strategy, VSMCs were treated with TGF-ß in the presence or absence of tamoxifen, raloxifene, and various pharmacological inhibitors. Subsequently, CHSY1 mRNA expression, Smad2C and Smad2L phosphorylation, ROS production, p47phox and ERK 1/2 phosphorylation were assessed. Our results revealed that tamoxifen and raloxifene significantly attenuated TGF-ß-mediated CHSY1 mRNA expression and Smad2 linker region phosphorylation, without affecting the canonical TGF-ß-Smad2C pathway. Furthermore, these compounds effectively inhibited ROS production, p47phox and ERK 1/2 phosphorylation, implicating the involvement of the TGF-ß-NOX-ERK-Smad2L signaling cascade in their cardioprotective properties. This study provides a comprehensive understanding of the molecular mechanisms underlying the cardioprotective effects of tamoxifen and raloxifene in VSMCs, offering valuable insights for the development of targeted therapeutic strategies aimed at atherosclerosis prevention and the promotion of cardiovascular health.

Tamoxifen and the risk of breast cancer in women with a BRCA1 or BRCA2 mutation.

PURPOSE: Chemoprevention with a selective estrogen receptor modulator (tamoxifen or raloxifene) is a non-surgical option offered to high-risk women to reduce the risk of breast cancer. The evidence for tamoxifen benefit is based on trials conducted among predominantly postmenopausal women from the general population and on studies of contralateral breast cancer in women with a pathogenic variant (mutation hereafter) in BRCA1 or BRCA2. Tamoxifen has not been assessed as a primary prevention agent in women with an inherited BRCA mutation. METHODS: We conducted a prospective analysis of tamoxifen chemoprevention and the risk of breast cancer in women with a BRCA1 or BRCA2 mutation. Data on tamoxifen (and raloxifene) use was collected by questionnaire and updated biennially. Information on incident cancers was collected by self-report and was confirmed by medical record review. In a matched analysis, we estimated the hazard ratio (HR) and 95% confidence intervals (CI) for developing a first primary breast cancer associated with tamoxifen or raloxifene use, using Cox proportional hazards analysis. RESULTS: There were 4578 unaffected women in the cohort, of whom 137 reported tamoxifen use (3%), 83 reported raloxifene use (2%) and 12 used both drugs (0.3%). Women who used tamoxifen or raloxifene were matched 1:3 with women who used neither drug on year of birth, country of residence, year of study entry and gene (BRCA1 or BRCA2). We generated 202 matched pairs. After a mean follow-up of 6.8 years, there were 22 incident breast cancers diagnosed among tamoxifen/raloxifene users (10.9% of users) and 71 cases diagnosed among non-users (14.3% of non-users; HR = 0.64; 95% CI 0.40-1.03; P = 0.07). CONCLUSION: Chemoprevention may be an effective risk-reduction option for BRCA mutation carriers, but further studies with longer follow-up are necessary.

Estradiol and raloxifene as adjunctive treatment for women with schizophrenia: A meta-analysis of randomized, double-blind, placebo-controlled trials.

OBJECTIVES: We conducted a comprehensive meta-analysis of all available trials to evaluate the efficacy and safety of estrogen and selective estrogen receptor modulators as adjunctive treatment for women with schizophrenia. METHODS: Multiple databases were searched from the inception until March 2022. Only randomized, double-blind, placebo-controlled studies (randomized controlled trials) were included. Mean differences (MDs) and their 95% confidence intervals (CIs) were calculated using random effects models. RESULTS: The meta-analysis included six estradiol versus placebo studies (n = 724) and seven raloxifene versus placebo studies (n = 419), covering a total of 1143 patients. Adjunctive estradiol outperformed the placebo in terms of the Positive and Negative Syndrome Scale (PANSS) total score (MD = -7.29; 95% CI = -10.67 to -3.91; I2  = 59.1%; p < 0.001; k = 9; N = 858), positive symptom score (MD = -1.54; 95% CI = -3.04 to -0.72; I2  = 45.8%; p < 0.001; k = 7; N = 624), negative symptom score (MD = -1.9; 95% CI = -1.77 to -0.34; I2  = 37.6%; p < 0.05; k = 14; N = 1042), and general psychopathology score (MD = -4.27; 95% CI = -7.14 to -1.41; I2  = 76.3%; p < 0.005; k = 7; N = 624). Adjunctive raloxifene outperformed the placebo in terms of the PANSS total score (MD = -6.83; 95% CI = -11.69 to -1.97; I2  = 67.8%; p = 0.006; k = 8; N = 432) and general psychopathology score (MD = -3.82; 95% CI = -6.36 to -1.28; I2  = 65.3%; p < 0.005; k = 8; N = 432). CONCLUSIONS: Our meta-analysis showed that estradiol and raloxifene are effective and safe adjunctive treatments that improve schizophrenia symptoms in women. Moreover, the effects of estradiol and raloxifene differed in terms of timing and dosage. Both are promising adjunctive treatments that merit further study.

Evidence-Based Recommendations for the Pharmacological Treatment of Women with Schizophrenia Spectrum Disorders.

PURPOSE OF REVIEW: Despite clear evidence that sex differences largely impact the efficacy and tolerability of antipsychotic medication, current treatment guidelines for schizophrenia spectrum disorders (SSD) do not differentiate between men and women. This review summarizes the available evidence on strategies that may improve pharmacotherapy for women and provides evidence-based recommendations to optimize treatment for women with schizophrenia. RECENT FINDINGS: We systematically searched PubMed and Embase for peer-reviewed studies on three topics: (1) sex differences in dose-adjusted antipsychotic serum concentrations, (2) hormonal augmentation therapy with estrogen and estrogen-like compounds to improve symptom severity, and (3) strategies to reduce antipsychotic-induced hyperprolactinemia. Based on three database studies and one RCT, we found higher dose-adjusted concentrations in women compared to men for most antipsychotics. For quetiapine, higher concentrations were specifically found in older women. Based on two recent meta-analyses, both estrogen and raloxifene improved overall symptomatology. Most consistent findings were found for raloxifene augmentation in postmenopausal women. No studies evaluated the effects of estrogenic contraceptives on symptoms. Based on two meta-analyses and one RCT, adjunctive aripiprazole was the best-studied and safest strategy for lowering antipsychotic-induced hyperprolactinemia. Evidence-based recommendations for female-specific pharmacotherapy for SSD consist of (1) female-specific dosing for antipsychotics (guided by therapeutic drug monitoring), (2) hormonal replacement with raloxifene in postmenopausal women, and (3) aripiprazole addition as best evidenced option in case of antipsychotic-induced hyperprolactinemia. Combining these strategies could reduce side effects and improve outcome of women with SSD, which should be confirmed in future longitudinal RCTs.

The contribution of larval zebrafish transcriptomics to chemical risk assessment.

In Canada, the Canadian Environmental Protection Act (1999) requires human health and environmental risk assessments be conducted for new substances prior to their manufacture or import. While this toxicity data is historically obtained using rodents, in response to the international effort to eliminate animal testing, Health Canada is collaborating with the National Research Council (NRC) of Canada to develop a New Approach Method by refining existing NRC zebrafish models. The embryo/larval zebrafish model evaluates systemic (whole body) general toxicity which is currently unachievable with cell-based testing. The model is strengthened using behavioral, toxicokinetic and transcriptomic responses to assess non-visible indicators of toxicity following chemical exposure at sub-phenotypic concentrations. In this paper, the predictive power of zebrafish transcriptomics is demonstrated using two chemicals; Raloxifene and Resorcinol. Raloxifene exposure produced darkening of the liver and malformation of the nose/mandible, while Resorcinol exposure produced increased locomotor activity. Transcriptomic analysis correlated differentially expressed genes with the phenotypic effects and benchmark dose calculations determined that the transcriptomic Point of Departure (POD) occurred at subphenotypic concentrations. Correlating gene expression with apical (phenotypic) effects strengthens confidence in evaluation of chemical toxicity, thereby demonstrating the significant advancement that the larval zebrafish transcriptomics model represents in chemical risk assessment.

Development of Subdermal Implants Using Direct Powder Extrusion 3D Printing and Hot-Melt Extrusion Technologies.

Implants are drug delivery platforms that consist of a drug-polymer matrix with the ability of providing a localized and efficient controlled release of the drug with minimal side effects and achievement of the desired therapeutic outcomes with low drug loadings. Direct powder extrusion (DPE) 3D printing technology involves the extrusion of material through a nozzle of the printer in the form of pellets or powder. The present study aimed at investigating the use of the CELLINK BIO X™ bioprinter using DPE 3D printing technique to fabricate and evaluate the impact of different shapes (cuboid, cylinder, and tube) of raloxifene hydrochloride (RFH)-loaded subdermal implants on the release of RFH from the implants. This study further evaluated the impact of different processing techniques, viz., hot-melt extrusion (HME) technology vs. DPE 3D printing technique, on the release of RFH from the implants fabricated by each processing technique. All the fabricated implants were characterized by XRD, DSC, SEM, and FTIR, and evaluated for their water uptake, mass loss, and in vitro RFH release. The current study successfully demonstrated a great opportunity of controlling and/or tuning the release of RFH from the subdermal implants by altering the implant shape, and hence surface area, and could be a great contribution and/or addition to the personalization of medicines and improvement of patient compliance.

The Interplay of Raloxifene and Sonochemical Bio-Oss in Early Maxillary Sinus Bone Regeneration: A Histological and Immunohistochemical Analysis in Rabbits.

The study aimed to assess the efficacy of using Raloxifene with ultrasonic processing to enhance Bio-Oss®, a bone graft substitute, for maxillary sinus bone height reconstruction. A total of 24 rabbit maxillary sinuses were distributed into three groups, each receiving different treatments: Bio-Oss® only, sonicated Bio-Oss, and sonicated Bio-Oss® with Raloxifene. Surgical procedures and subsequent histomorphometric and immunohistochemistry analyses were conducted to evaluate the bone formation, connective tissue, and remaining biomaterial, as well as the osteoblastic differentiation and maturation of collagen fibers. Results indicated that the sonicated Bio-Oss® and Bio-Oss® groups showed similar histological behavior and bone formation, but the Raloxifene group displayed inflammatory infiltrate, low bone formation, and disorganized connective tissue. The statistical analysis confirmed significant differences between the groups in terms of bone formation, connective tissue, and remaining biomaterial. In conclusion, the study found that while sonicated Bio-Oss® performed comparably to Bio-Oss® alone, the addition of Raloxifene led to an unexpected delay in bone repair. The findings stress the importance of histological evaluation for accurate bone repair assessment and the necessity for further investigation into the local application of Raloxifene. Future research may focus on optimizing bone substitutes with growth factors to improve bone repair.

Effect of follow-up raloxifene therapy after denosumab discontinuation in postmenopausal women.

Follow-up raloxifene therapy after denosumab discontinuation resulted in a decrease in bone mass to the pre-denosumab levels and a rebound increase of bone turnover markers. The decrease in lumbar bone mineral density was particularly evident when the body mass index was low, there were previous vertebral fractures, or lumbar bone mineral density before denosumab administration was low. INTRODUCTION: Selective estrogen receptor modulators may be an alternative to bisphosphonates for treating rebound resorption after discontinuing denosumab. This study aimed to investigate the effects of follow-up raloxifene therapy after denosumab discontinuation in postmenopausal women. METHODS: This retrospective observational study included 61 patients who received 12-month follow-up raloxifene therapy after denosumab discontinuation. The primary endpoint was the bone mineral density change. The secondary endpoints were the changes in bone turnover markers and the incidence of new vertebral fractures. RESULTS: Raloxifene administration for 12 months after denosumab discontinuation resulted in a significantly lower bone mineral density at all sites compared to the level at 6 months after the last denosumab treatment (lumbar spine, - 5.48%; femoral neck, - 2.95%; total hip, - 3.52%; all, p < 0.001). The decrease in lumbar bone mineral density was particularly evident when the body mass index was low, there were previous vertebral fractures, or lumbar bone mineral density before denosumab administration was low. Marked increases in the bone turnover markers from baseline were noted after switching to raloxifene. However, no new vertebral fractures occurred during raloxifene treatment. CONCLUSIONS: Follow-up raloxifene therapy after denosumab discontinuation resulted in a decrease in bone mass to the pre-denosumab levels and a rebound increase of bone turnover markers. Therefore, raloxifene administered sequentially after denosumab discontinuation was not effective in preventing rebound phenomenon.

Raloxifene, a cannabinoid type-2 receptor inverse agonist, mitigates visual deficits and pathology and modulates microglia after ocular blast.

Visual deficits after ocular blast injury (OBI) are common, but pharmacological approaches to improve long-term outcomes have not been identified. Blast forces frequently damage the retina and optic nerves, and work on experimental animals has shown the pro-inflammatory actions of microglia can further exacerbate such injuries. Cannabinoid type-2 receptor (CB2) inverse agonists specifically target activated microglia, biasing them away from the harmful pro-inflammatory M1 state toward the helpful reparative M2 state. We previously found that treating mice with CB2 inverse agonists after traumatic brain injury, produced by either focal cranial air blast or dorsal cranial impact, greatly attenuated the visual deficits and pathology that otherwise resulted. Here we examined the consequences of single and repeat OBI and the benefit provided by raloxifene, an FDA-approved estrogen receptor drug that possesses noteworthy CB2 inverse agonism. After single OBI, although the amplitudes of the A- and B-waves of the electroretinogram and pupil light response appeared to be normal, the mice showed hints of deficits in contrast sensitivity and visual acuity, a trend toward optic nerve axon loss, and significantly increased light aversion, which were reversed by 2 weeks of daily treatment with raloxifene. Mice subjected to repeat OBI (5 blasts spaced 1 min apart), exhibited more severe visual deficits, including decreases in contrast sensitivity, visual acuity, the amplitudes of the A- and B-waves of the electroretinogram, light aversion, and resting pupil diameter (i.e. hyperconstriction), accompanied by the loss of photoreceptor cells and optic nerve axons, nearly all of which were mitigated by raloxifene. Interestingly, optic nerve axon abundance was strongly correlated with contrast sensitivity and visual acuity across all groups of experimental mice in the repeat OBI study, suggesting optic nerve axon loss with repeat OBI and its attenuation with raloxifene are associated with the extent of these two deficits while photoreceptor abundance was highly correlated with A-wave amplitude and resting pupil size, suggesting a prominent role for photoreceptors in these two deficits. Quantitative PCR (qPCR) showed levels of M1-type microglial markers (e.g. iNOS, IL1ß, TNFα, and CD32) in retina, optic nerve, and thalamus were increased 3 days after repeat OBI. With raloxifene treatment, the overall expression of M1 markers was more similar to that in sham mice. Raloxifene treatment was also associated with the elevation of IL10 transcripts in all three tissues compared to repeat OBI alone, but the results for the three other M2 microglial markers we examined were more varied. Taken together, the qPCR results suggest that raloxifene benefit for visual function and pathology was associated with a lessening of the pro-inflammatory actions of microglia. The benefit we find for raloxifene following OBI provides a strong basis for phase-2 efficacy testing in human clinical trials for treating ocular injury.

Raloxifene Use After Denosumab Discontinuation Partially Attenuates Bone Loss in the Lumbar Spine in Postmenopausal Osteoporosis.

Discontinuation of denosumab (DMab) is associated with decline in bone density. Whether raloxifene can be effective to attenuate bone loss after DMab discontinuation in certain conditions when other antiresorptives cannot be used remains unclear. Data on postmenopausal women with osteoporosis who discontinued DMab treatment after short-term use (1-to-4 doses) at Severance Hospital, Seoul, Korea, between 2017 and 2021 were reviewed. Changes in bone mineral density (BMD) at 12 months after DMab discontinuation was compared between sequential raloxifene users (DR) and those without any sequential antiresorptive (DD) after 1:1 propensity score matching. In matched cohort (66 patients; DR n = 33 vs. DD n = 33), mean age (69.3 ± 8.2 years) and T-score (lumbar spine - 2.2 ± 0.7; total hip - 1.6 ± 0.6) did not differ between two groups at the time of DMab discontinuation. Sequential treatment to raloxifene in DR group attenuated the bone loss in lumbar spine after DMab discontinuation compared to DD group (DR vs. DD; - 2.8% vs. - 5.8%, p = 0.013). The effect of raloxifene on lumbar spine BMD changes remained robust (adjusted ß + 2.92 vs. DD, p = 0.009) after adjustment for covariates. BMD loss at femoral neck (- 1.70% vs. - 2.77%, p = 0.673) and total hip (- 1.42% vs. - 1.44%, p = 0.992) did not differ between two groups. Compared to BMD at DMab initiation, DR partially retained BMD gain by DMab treatment in lumbar spine (+ 3.7%, p = 0.003) and femoral neck (+ 2.8%, p = 0.010), whereas DD did not. Raloxifene use after DMab treatment attenuated lumbar spine BMD loss in postmenopausal women with short exposures (< 2 years) to DMab.

A combined treatment with selective androgen and estrogen receptor modulators prevents bone loss in orchiectomized rats.

PURPOSE: Enobosarm (EN), a selective androgen receptor modulator and raloxifene (RAL), a selective estrogen receptor modulator, have been shown to improve bone tissue in osteoporotic males. The present study evaluated the effects of a combination therapy of EN and RAL on bone properties in orchiectomized rats compared to the respective single treatments. METHODS: Eight-month-old male Sprague-Dawley rats were either left intact (Non-Orx) or orchiectomized (Orx). The Orx rats were divided into four groups (n = 15 each): 1) Orx, 2) EN treatment (Orx + EN), 3) RAL treatment (Orx + RAL), 4) combined treatment (Orx + EN + RAL). EN and RAL (0.4 mg and 7 mg/kg body weight/day) were applied immediately after Orx with a soy-free pelleted diet for up to 18 weeks. The lumbar spine and femora were examined by micro-CT, biomechanical, histomorphological, ashing, and gene expression analyses. RESULTS: EN exhibited an anabolic effect on bone, improving some of its parameters in Orx rats, but did not affect biomechanical properties. RAL exhibited antiresorptive activity, maintaining the biomechanical and trabecular parameters of Orx rats at the levels of Non-Orx rats. EN + RAL exerted a stronger effect than the single treatments, improving most of the bone parameters. Liver weight increased after all treatments; the kidney, prostate, and levator ani muscle weights increased after EN and EN + RAL treatments. BW was reduced due to a decreased food intake in the Orx + RAL group and due a reduced visceral fat weight in the Orx + EN + RAL group. CONCLUSION: The EN + RAL treatment appeared to be promising in preventing male osteoporosis, but given the observed side effects on liver, kidney, and prostate weights, it requires further investigation.

Raloxifene HCl - quercetin co-amorphous system: preparation, characterization, and investigation of its behavior in phosphate buffer.

PURPOSE: Raloxifene HCl (RLX), a practically insoluble drug used in the treatment of osteoporosis in post-menopausal women; was modified at its molecular level to enhance its solubility using co-amorphous technology. METHODS: In this study, RLX was co-amorphized with Quercetin (QCT; a nutraceutical flavonoid) using solvent evaporation (SE), quench cooling (QC), and ball milling (BM) techniques. The prepared co-amorphous systems (CAMs) were characterized using XRD, DSC, and FT-IR. For the simultaneous analysis of RLX and QCT, an RP-HPLC method was developed to quantify the drugs in the prepared systems. Behavior in aqueous media was investigated by studying amorphous and equilibrium solubility, and drug release of RLX using USP phosphate buffer pH 6.8. RESULTS: Solvent evaporation (RQ(SE)) was able to produce a homogeneous system, where quench cooling showed thermal degradation of the drug, and ball milling was not able to amorphize the blend. From the DSC results, it was found that RQ(SE) was able to increase the glass transition temperature by 40 °C. It was observed that the solubility of RLX reduced, as RLX formed phosphate aggregates in the buffer media which further formed complexes with QCT; this was determined by investigating the residual particles from solubility studies. Though the solubility was reduced, drug release of RQ(SE) exhibited improvement in concentration by 2.3 times. CONCLUSIONS: RQ(SE) formed a stable CAM; though the solubility of RLX in presence of QCT reduced, from the drug release study, it was apparent that the co-amorphous technique improved the concentration of RLX.