Effect of Raloxifene Treatment on Apolipoproteins and Lipoprotein(a) Concentrations in Postmenopausal Women: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND AIM

Although various randomized controlled trials (RCTs) have evaluated the effect of raloxifene on apolipoproteins and lipoprotein(a) concentrations in postmenopausal women, the results have been inconsistent and inconclusive. Therefore, we conducted this meta-analysis of RCTs to investigate the effect of raloxifene administration on apolipoproteins and lipoprotein(a) [Lp(a)] concentrations in postmenopausal women.

METHODS

Two independent researchers systematically searched the scientific literature (including PubMed/Medline, Scopus, Web of Science, and EMBASE) for English-language randomized controlled trials (RCTs) published up to June 2024. We included RCTs reporting the impact of raloxifene on apolipoprotein A-I (ApoA-I), apolipoprotein B (ApoB), and Lp(a) levels in postmenopausal women. The primary outcome of interest was change in Lp(a), and the secondary outcomes were changes in ApoA-I and ApoB.

FINDINGS

The present meta-analysis incorporated 12 publications with 14 RCT arms. The comprehensive outcomes derived from the random-effects model revealed a statistically significant increase in ApoA-I (WMD: 6.06 mg/dL, 95% CI: 4.38, 7.75, P < 0.001) and decrease in ApoB concentrations (WMD: -8.48 mg/dL, 95% CI: -10.60, -6.36, P < 0.001) and Lp(a) (WMD: -3.02 mg/dL, 95% CI: -4.83, -1.21, P < 0.001) following the administration of raloxifene in postmenopausal women. In the subgroup analyses, the increase in ApoA-I and the decrease in ApoB and Lp(a) levels were greater in RCTs with a mean participant age of ≥60 years and a duration of ≤12 weeks.

IMPLICATIONS

The current meta-analysis of RCTs demonstrates that treatment with raloxifene reduces ApoB and Lp(a) levels while increasing ApoA-I levels in postmenopausal women. Since these effects on lipid components are associated with a reduced risk of cardiovascular disease (CVD), raloxifene could be a suitable therapy for postmenopausal women who are at an increased risk of CVD and have other medical indications for raloxifene administration.

Raloxifene encapsulated spanlastic nanogel for the prevention of bone fracture risk via transdermal administration: Pharmacokinetic and efficacy study in animal model

This research work is to evaluate spanlastic-loaded raloxifene (RLX) nanogel administration via the transdermal route to avoid its hepatic metabolism and to enhance the bioavailability for better management of osteoporosis. RLX-loaded spanlastic nanogel was prepared and characterized for its viscosity, pH, spreadability, and texture profile. The formulation was applied on the skin surface of the animal for pharmacokinetic evaluation, and later, the efficacy of the formulation was assessed in ovariectomized female Wistar rats. The nanogel was obtained with a viscosity (2552.66 ± 30.61 cP), pH (7.1 ± 0.1), and spreadability (7.1 ± 0.2 cm). The texture properties, cohesiveness, and adhesiveness of the nanogel showed its suitability for transdermal application. Nanogel showed no sign of edema and erythema in the skin irritation test which revealed its safety for transdermal application. The t1/2 obtained for RLX-spanlastic nanogel (37.02 ± 0.59 h) was much higher than that obtained for RLX-oral suspension (14.43 h). The relative bioavailability was found to be 215.96% for RLX-spanlastic nanogel, and the drug and formulation did not show any toxicity in any of the vital organs, as well as no hematological changes occurring in blood samples. In microarchitectural measurement, RLX-spanlastic nanogel exhibited no unambiguous deviations along with improved bone mineral density compared to the RLX suspension treated group. Transdermal administration of RLX-spanlastic nanogel showed significant improvement of drug bioavailability (approx. twice to oral administration) without any toxic effect in the treated rats. Hence, spanlastic nanogel could be a better approach to deliver RLX via transdermal route for the management of osteoporosis.

Enhanced oral bioavailability of levormeloxifene and raloxifene by nanoemulsion: simultaneous bioanalysis using liquid chromatography-tandem mass spectrometry

Aim & objective: Levormeloxifene (L-ORM) and raloxifene (RAL) are selective estrogen receptor modulators used in the treatment of postmenopausal osteoporosis and breast cancer. Here, we developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous estimation of both drugs. Materials & methods: A quality-by-design (QbD) approach was used for the optimization of the nanoemulsion, and US FDA guidelines were followed for method validation. Results: Multiple reaction monitoring transitions were used for L-ORM (459.05→98.50), RAL (475.00→112.02) and internal standard (180.10→110.2). Analytes were resolved in a C18 column with 80:20 v/v% acetonitrile (ACN), 0.1% formic acid in triple-distilled water as a mobile phase. The developed method was linear over a concentration range of 1-600 ng/ml. Pharmacokinetic results of free L-ORM-RAL and the L-ORM-RAL nanoemulsion showed Cmax of free L-ORM - 70.65 ± 16.64, free RAL 13.53 ± 2.72, L-ORM nanoemulsion 65.07 ± 14.0 and RAL-nanoemulsion 59.27 ± 17.44 ng/ml. Conclusion: Future findings will contribute to the treatment of postmenopausal osteoporosis and breast cancer using L-ORM and RAL.

[Development of Transdermal Formulation Based on Nanotechnology and Elucidation of Its Drug Delivery Pathways]

Transdermal drug delivery is a formulation in which the drug is absorbed through the skin for systemic action. Its advantages include avoidance of first-pass effects, sustained drug supply, and ease of administration and discontinuation. Drugs administered transdermally transfer into the blood circulation through the stratum corneum, epidermis, and dermis. The stratum corneum on the skin surface plays a barrier function in skin absorption. Therefore, developing of transdermal drug delivery systems requires innovations that overcome the barrier function of the stratum corneum and improve skin permeation. This review examines the usefulness of transdermal formulations based on solid nanoparticles using raloxifene. Milled raloxifene was gelled with (mRal-NPs) or without menthol (Ral-NPs) using Carbopol. The drug release and transdermal penetration were measured using a Franz diffusion cell, and the therapeutic evaluation of osteoporosis was determined in an ovariectomized rat model. Although the raloxifene released from Ral-NPs remained in the nanoparticle state, the skin penetration of raloxifene nanoparticles was prevented by the stratum corneum in rat. The inclusion of menthol in the formulation attenuated the barrier function of the stratum corneum and permitted raloxifene nanoparticles to penetrate through the skin. Moreover, macropinocytosis relates to the formulation's skin penetration, including menthol (mRal-NPs). Applying mRal-NPs attenuated the decreases in calcium level and stiffness of bones of ovariectomized rats. This information can support future studies aimed at designing novel transdermal formulations.

Effects of raloxifene administration on serum levels of insulin-like growth factor-1 and insulin-like growth factor-binding protein 3 levels: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To ascertain the clinical magnitude of raloxifene administration on insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein 3 (IGFBP-3) levels.

METHODS

A systematic comprehensive search was performed without language limitation up to 14 December 2020. We included only trials that assessed the effect of raloxifene on IGF-1 and IGFBP-3 in adults. Meta-analysis was performed using the Stata software (Stata Corp. College Station, Texas, USA).

RESULTS

Seven arms were included, encompassing postmenopausal women with type 2 diabetes mellitus, postmenopausal women with breast cancer, healthy postmenopausal women, and healthy elderly men. Raloxifene therapy significantly reduced IGF-1 levels (WMD: -2.92 nmol/L, 95% CI: -3.49, -2.35, p < 0.001) compared to placebo. Raloxifene dosage ˃60 mg/day (WMD: -3.29 ng/mL, 95% CI: -3.50 to -3.08, I² = 0.0%) decreased IGF-1 levels more than 60 mg/day (WMD: -2.29 ng/mL, 95% CI: -2.90 to -1.69, I² = 16%). Moreover, intervention duration ˃26 weeks (WMD: -3.48 ng/mL, 95% CI: -5.26 to -1.69, I² = 0.0%) reduced IGF-1 levels more than ˂26 weeks (WMD: -2.55 ng/mL, 95% CI: -3.31 to -1.79, I² = 92%). In contrast, overall results from the random-effects model did not suggest a significant change in IGFBP-3 levels upon raloxifene therapy.

CONCLUSION

Raloxifene therapy significantly reduced serum levels of IGF-1 levels but without changes in IGFPB-3 levels.

Preventing Breast Cancer Through Identification and Pharmacologic Management of High-Risk Patients

Breast cancer remains the most common cancer in women in the United States. For certain women at high risk for breast cancer, endocrine therapy (ET) can greatly decrease the risk. Tools such as the Breast Cancer Risk Assessment Tool (or Gail Model) and the International Breast Cancer Intervention Study risk calculator are available to help identify women at increased risk for breast cancer. Physician awareness of family history, reproductive and lifestyle factors, dense breast tissue, and history of benign proliferative breast disease are important when identifying high-risk women. The updated US Preventive Services Task Force and American Society of Clinical Oncology guidelines encourage primary care providers to identify at-risk women and offer risk-reducing medications. Among the various ETs, which include tamoxifen, raloxifene, anastrozole, and exemestane, tamoxifen is the only one available for premenopausal women aged 35 years and older. A shared decision-making process should be used to increase the usage of ET and must be individualized. This individualized approach must account for each woman's medical history and weigh the benefits and risks of ET in combination with the personal values of the patient.

Nanostructured lipid carrier potentiated oral delivery of raloxifene for breast cancer treatment

Nanotherapeutics in cancer treatment are dominating global science and research, and have been recognized as the pioneering medical care regimen. Raloxifene (RLN) has been used for its anti-proliferative action on mammary tissue, however, it suffers from poor oral bioavailability. This investigation gives an account of the design and development of RLN-loaded nanostructured lipid carriers (RLN-NLCs) using a simple and scalable ultrasonication method for improved oral efficacy and limited offsite toxicity using Compritol^® 888 ATO as a solid lipid and Transcutol^® HP as a liquid lipid. In addition, the optimized RLN-NLCs were in the nanometric range (121 nm) with high % entrapment efficiency (%EE) (81%) for RLN, and were further freeze-dried in the presence of mannitol to enhance the stability of RLN-NLCs in the dry state for long-term use. Morphological observation under a transmission electron microscope and scanning electron microscope revealed the spherical smooth surface nanometric size of RLN-NLCs. Powder x-ray diffraction confirmed the encapsulation of RLN into the RLN-NLC's matrix with reduced crystallinity of the drug. The in vitro release study showed a burst release for an initial 4 h, and sustained release for up to 24 h. Furthermore, the RLN-NLCs showed higher cytotoxicity towards MCF-7 cells in vitro in comparison to RLN suspension, and an ex vivo intestinal permeation study demonstrated improved intestinal permeability of RLN-NLCs. Moreover, the in vivo pharmacokinetic study in female Wistar rats showed a 4.79-fold increment in oral bioavailability of RLN from RLN-NLCs compared to RLN suspension. Taken together, our results pave the way for a new nanotherapeutic approach towards breast cancer treatment.

Effectiveness of antiresorptive medications in women on long-term dialysis after hip fracture: A population-based cohort study

There is no clear evidence how effective the antiresorptive (AR) drugs alendronate and raloxifene are at reducing risk of second hip fracture and mortality in dialysis populations. The purpose of this study was to compare the risk of hospitalization for second hip fracture and risk of mortality between AR user and non-user groups in Taiwanese women on long-term dialysis with hip fractures. We conducted a retrospective cohort study using Taiwan National Health Insurance Research Datasets. Long-term dialysis women older than 50 years with newly diagnosed hip fractures and new to AR therapy from 2005 to 2011 were recruited. The patients were divided into AR users and non-users and matched by propensity score. We used Cox Proportional Hazards models to assess association of AR with risks of second hip fracture and mortality. Totally, 1,079 dialysis patients were included, and after matching, we were left with 74 AR users and 74 non-users. AR users did not show a significant reduction in the incidence of second hip fracture compared with non-users (adjusted Hazard Ratio (HR): 0.91, 95% CI: 0.30-2.76), and alendronate users exhibited higher risk of second hip fracture compared with raloxifene users (adjusted HR: 2.80, 95% CI: 0.42-18.79). In addition, AR users were found to have significantly lower 1- and 2-year mortality rates than the non-users (1- year: adjusted HR 0.25, 95% CI, 0.07-0.90; 2-year: 0.35, 95%CI: 0.17-0.72). AR treatment did not significantly improve the risk of second hip fracture but significantly reduce mortality in older women on dialysis. Further clinical trials on effectiveness of AR medications for dialysis populations should be warranted.

Raloxifene potentiates the effect of fluoxetine against maximal electroshock induced seizures in mice

The evidence to guide clinicians regarding rationale polytherapy with current antiepileptic drugs (AEDs) is lacking, and current practice recommendations are largely empirical.  The excessive drug loading with combinatorial therapies of existing AEDs are associated with escalated neurotoxicity, and that emergence of pharmacoresistant seizures couldn't be averted. In pursuit of judicious selection of novel AEDs in combinatorial therapies with mechanism based evidences, standardized dose of raloxifene, fluoxetine, bromocriptine and their low dose combinations, were experimentally tested for their impact on maximal electroshock (MES) induced tonic hind limb extension (THLE) in mice. Hippocampal neuropeptide Y (NPY) levels, oxidative stress and histopathological studies were undertaken. The results suggest the potentiating effect of 4 mg/kg raloxifene on 14 mg/kg fluoxetine against MES induced THLE, as otherwise monotherapy with 4 mg/kg raloxifene was unable to produce an effect. The results also depicted better efficacy than carbamazepine (20 mg/kg), standard AED. Most profoundly, MES-induced significant (P < 0.001) reduction in hippocampal NPY levels, that were escalated insignificantly with the duo-drug combination, suggesting some other mechanism in mitigation of electroshock induced seizures. These results were later corroborated with assays to assess oxidative stress and neuronal damage. In conclusion, the results demonstrated the propitious therapeutic benefit of duo-drug low dose combination of drugs; raloxifene and fluoxetine, with diverse mode of actions fetching greater effectiveness in the management of generalized tonic clonic seizures (GTCS).

Efficacy of combined medication of risedronate sodium and selective estrogen receptor modulator on the postmenopausal osteoporosis

To evaluate the efficacy of combined medication of risedronate sodium and raloxifene, a selective estrogen receptor modulator (SERM) on the postmenopausal osteoporosis (PMOP). PMOP patients underwent the combined medication of risedronate sodium and raloxifene (SERM, Treatment group), or only medication of risedronate sodium (Control group). After medication, more significant increases were observed in the bone densities of the lumber vertebra (L<inf>1-4</inf>) and the neck of left femur of patients in the treatment group. Simultaneously, the levels of estrogen and progesterone in serum decreased sharply in the treatment group. After treatment, P1NP and β-CTX levels in serum decreased significantly in two groups in comparison with the levels prior to treatment, with evident elevations in the levels of BAP and BGP; similarly, ameliorations in the treatment group were much more evident than those in the control group. In addition, significant declines were identified in the VAS scores of two groups after treatment when comparing to the scores prior to the treatment, and the decline in the treatment group was more evident than that in the control group. Combined medication of risedronate sodium and SERM (raloxifene) performs better in treatment of osteoporosis than the single use of risedronate sodium, without the deterioration of adverse effect of medication.

Vitamin E TPGS based transferosomes augmented TAT as a promising delivery system for improved transdermal delivery of raloxifene

Raloxifene is commonly used for breast cancer protection. The low bioavailability of raloxifene (2%) is the result of its low solubility and intestinal glucuronidation. The nano-lipid carriers are characterized by small particle size, biocompatibility, and sustainable properties that improve cellular uptake of the loaded drug. The aim of this study was the improvement of raloxifene bioavailability by enhancing its solubility and cellular penetration through formulation of D-α-tocopheryl polyethylene glycol 1000 succinate based transferosomes and augmenting their effect with the cationic cell-penetrating peptide transactivator of transcription of the human immunodeficiency virus. Particle size, zeta potential, and transmission electron microscope investigation of the formed nanocarriers were carried out. Ex vivo raloxifene permeation through rat skin and cell viability studies was investigated. The results of D-α-tocopheryl polyethylene glycol 1000 succinate- transactivator of transcription of the human immunodeficiency virus transferosomes showed an average vesicle size of 96.05 nm with positively charged vesicles 39.4 mV of zeta potential value. The results revealed significant (p < 0.05) enhancement of raloxifene permeation from raloxifene transferosomes- loaded film when compared with raw raloxifene film. IC50 results showed significant improvement of formulated raloxifene cytotoxicity by 1.42-fold in comparison with raw raloxifene against MCF-7 cell lines. The developed raloxifene-transferosomes are considered promising nano-lipid carriers for the enhancement delivery of raloxifene.

Specificity proteins 1 and 4 in peripheral blood mononuclear cells in postmenopausal women with schizophrenia: a 24-week double-blind, randomized, parallel, placebo-controlled trial

Accumulating evidence suggests that Specificity Protein 1 (SP1) and 4 (SP4) transcription factors are involved in the pathophysiology of schizophrenia. The therapeutic use of selective oestrogen modulators such as raloxifene added to antipsychotic drugs in the treatment of postmenopausal women with schizophrenia has been investigated in a few clinical trials, which reported an improvement in negative, positive, and general psychopathological symptoms. We aimed to investigate the possible association between peripheral SP protein levels and symptom improvement in postmenopausal women with schizophrenia treated with adjuvant raloxifene. In a subgroup of 14 postmenopausal women with schizophrenia from a 24-week, randomized, parallel, double-blind, placebo-controlled clinical trial (NCT015736370), we investigated changes in SP1 and SP4 protein levels in peripheral blood mononuclear cells. Participants were randomized to either 60 mg/day adjunctive raloxifene or placebo. Psychopathological symptoms were assessed at baseline and at week 24 with the Positive and Negative Syndrome Scale (PANSS). The expression of SP proteins was evaluated by immunoblot, and changes in PANSS scores and protein levels were compared at baseline and after 24 weeks of treatment. An improvement in symptoms was observed in the intervention group, but not in placebo group. Post-treatment protein levels of SP4, but not SP1, correlated with improvements in general and total PANSS subscales in the raloxifene intervention group. A reduction in SP4 levels was found after raloxifene treatment. These results suggest that SP4 may be involved in raloxifene symptom improvement in postmenopausal women and could be a potential candidate for future studies investigating blood-based biomarkers for raloxifene effectiveness.

Long lasting in-situ forming implant loaded with raloxifene HCl: An injectable delivery system for treatment of bone injuries

Bone injury is very serious in elder people or osteoporotic patients. In-situ forming implants (IFI) for bone rebuilding are usually poly-lactic-co-glycolic acid (PLGA)-based, which have a burst release effect. This study aimed to prepare novel liquid lipid-based PLGA-IFI loaded with raloxifene hydrochloride for prolonged non-surgical treatment of bone injuries by applying solvent-induced phase inversion technique. Labrasol® and Maisine® were added to the selected IFI forming long lasting lipid-based IFI (LLL-IFI). The formulations were characterized by analysing their in-vitro drug release, solidification time, injectability, rheological properties, and DSC in addition to their morphological properties. Results revealed that the LLL-IFI composed of 10%w/v PLGA with a lactide to glycolide ratio of 75:25 with ester terminal and 10% Maisine® possessed the most sustained drug release and lowest burst effect, as well as delayed pore formation compared to its counterpart lacking Maisine®. The selected LLL-IFI and PLGA-IFI formulations were tested for their capability to enhance bone regeneration in bone injuries induced in rats. Both formulations succeeded in healing the bones completely with the superiority of LLL-IFI in the formation of well-organized bone structures lacking fibrous tissues. The results suggest that LLL-IFI and PLGA-IFI are innovative approaches for treating critical and non-critical sized bone injuries.

Production of a new platform based on fumed and mesoporous silica nanoparticles for enhanced solubility and oral bioavailability of raloxifene HCl

The purpose of the present study was to compare mesoporous and fumed silica nanoparticles (NPs) to enhance the aqueous solubility and oral bioavailability of raloxifene hydrochloride (RH). Mesoporous silica NPs (MSNs) and fumed silica NPs were used by freeze-drying or spray-drying methods. MSNs were obtained with different ratios of cetyltrimethylammonium bromide. Saturation solubility of the NPs was compared with the pure drug. The optimised formulation was characterised by scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry. The pharmacokinetic studies were done by oral administration of a single dose of 15 mg/kg of pure drug or fumed silica NPs of RH in Wistar rats. MSNs enhanced the solubility of RH from 19.88 ± 0.12 to 76.5 μg/ml. Freeze-dried fumed silica increased the solubility of the drug more than MSNs (140.17 ± 0.45 μg/ml). However, the spray-dried fumed silica caused about 26-fold enhancement in its solubility (525.7 ± 93.5 μg/ml). Increasing the ratio of silica NPs enhanced the drug solubility. The results of XRD and SEM analyses displayed RH were in the amorphous state in the NPs. Oral bioavailability of NPs showed 3.5-fold increase compared to the pure drug. The RH loaded fumed silica NPs prepared by spray-drying technique could more enhance the solubility and oral bioavailability of RH.

In situ misemgel as a multifunctional dual-absorption platform for nasal delivery of raloxifene hydrochloride: formulation, characterization, and in vivo performance

BACKGROUND

Raloxifene hydrochloride (RLX) is approved by the US Food and Drug Administration for the treatment and prevention of osteoporosis, in addition to reducing the risk of breast cancer in postmenopausal women. RLX has the disadvantages of low aqueous solubility, extensive presystemic intestinal glucuronidation, and first-pass metabolism, resulting in a limited bio-availability of only 2%. The aim of this work was to enhance the bioavailability of RLX via the formulation of an in situ nasal matrix (misemgel) comprising micelles made of vitamin E and D-α-tocopheryl polyethylene glycol 1000 succinate and nanosized self-emulsifying systems (NSEMS).

MATERIALS AND METHODS

Optimization of the RLX-loaded NSEMS was performed using a mixture design. The formulations were characterized by particle size and then incorporated into an in situ nasal gel. Transmission electron microscopy, bovine nasal mucosa ex vivo permeation, and visualization using a fluorescence laser microscope were carried out on the RLX in situ misemgel comparing with raw RLX in situ gel. In addition, the in vivo performance was studied in rats.

RESULTS

The results revealed improved permeation parameters for RLX misemgel compared with control gel, with an enhancement factor of 2.4. In vivo studies revealed a 4.79- and 13.42-fold increased bioavailability for RLX in situ misemgel compared with control RLX in situ gel and commercially available tablets, respectively. The obtained results highlighted the efficacy of combining two different formulations to enhance drug delivery and the benefits of utilizing different possible paths for drug absorption.

CONCLUSION

The developed in situ misemgel matrix could be considered as a promising multifunctional platform for nasal delivery which works based on a dual-absorption mechanism.

Effect of osteoporosis medication on changes in bone mineral density and bone turnover markers after 24-month administration of daily teriparatide: comparison among minodronate, raloxifene, and eldecalcitol

This study reveals the changes in bone mineral density (BMD), the turnover rate, and the balance [multiple of median formation/multiple of median resorption (MoMf/MoMr)] affected by the selection of different bone resorption inhibitors after 24-month daily teriparatide (20 µg/day) administration. The turnover rate was calculated as √(MoMf² + MoMr²), where MoMf = bone-specific alkaline phosphatase (BAP) value/18.6 and MoMr = tartrate-resistant acid phosphatase 5b (TRACP-5b) value/463. One hundred and twenty-one osteoporotic women (mean age 82.4 years) were randomly administered minodronate (50 mg/28 days), raloxifene (60 mg/day), or eldecalcitol (0.75 µg/day) after teriparatide discontinuation. BMD was measured at 0, 24, and 48 weeks; BAP values and TRACP-5b were measured at 0, 12, 24, 36, and 48 weeks after administration of bone resorption inhibitors. In the minodronate group, BMD increased significantly from week 0 to weeks 24 and 48. The turnover rate was significantly reduced at week 12, and remained so over the entire course in all three groups. The speed of change of turnover rate was greatest in the minodronate group. The balance in the minodronate group shifted significantly toward formation dominance at week 12 (to 0.97 from 0.87) and then again toward resorption dominance (to 0.84) at week 24. However, no further advancement in resorption dominance was observed until week 48. Conversely, the balance in the raloxifene and eldecalcitol groups shifted toward resorption dominance gradually over the entire course. In conclusion, the BMD-increasing effect was greatest with minodronate administration and depends not only on the decrease in turnover rate but also on changes in balance after teriparatide discontinuation.

[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.

RAZOR: A Phase II Open Randomized Trial of Screening Plus Goserelin and Raloxifene Versus Screening Alone in Premenopausal Women at Increased Risk of Breast Cancer

Background: Ovarian suppression in premenopausal women is known to reduce breast cancer risk. This study aimed to assess uptake and compliance with ovarian suppression using the luteinizing hormone releasing hormone (LHRH) analogue, goserelin, with add-back raloxifene, as a potential regimen for breast cancer prevention.Methods: Women at ≥30% lifetime risk breast cancer were approached and randomized to mammographic screening alone (C-Control) or screening in addition to monthly subcutaneous injections of 3.6 mg goserelin and continuous 60 mg raloxifene daily orally (T-Treated) for 2 years. The primary endpoint was therapy adherence. Secondary endpoints were toxicity/quality of life, change in bone density, and mammographic density.Results: A total of 75/950 (7.9%) women approached agreed to randomization. In the T-arm, 20 of 38 (52%) of women completed the 2-year period of study compared with the C-arm (27/37, 73.0%). Dropouts were related to toxicity but also the wish to have established risk-reducing procedures and proven chemoprevention. As relatively few women completed the study, data are limited, but those in the T-arm reported significant increases in toxicity and sexual problems, no change in anxiety, and less cancer worry. Lumbar spine bone density declined by 7.0% and visually assessed mammographic density by 4.7% over the 2-year treatment period.Conclusions: Uptake is somewhat lower than comparable studies with tamoxifen for prevention with higher dropout rates. Raloxifene may preserve bone density, but reduction in mammographic density reversed after treatment was completed.Impact: This study indicates that breast cancer risk reduction may be possible using LHRH agonists, but reducing toxicity and preventing bone changes would make this a more attractive option. Cancer Epidemiol Biomarkers Prev; 27(1); 58-66. ©2017 AACR.

Improving Combination Osteoporosis Therapy in a Preclinical Model of Heightened Osteoanabolism

Combining anticatabolic agents with parathyroid hormone (PTH) to enhance bone mass has yielded mixed results in osteoporosis patients. Toward the goal of enhancing the efficacy of these regimens, we tested their utility in combination with loss of the transcription factor Nmp4 because disabling this gene amplifies PTH-induced increases in trabecular bone in mice by boosting osteoblast secretory activity. We addressed whether combining a sustained anabolic response with an anticatabolic results in superior bone acquisition compared with PTH monotherapy. Additionally, we inquired whether Nmp4 interferes with anticatabolic efficacy. Wild-type and Nmp4-/- mice were ovariectomized at 12 weeks of age, followed by therapy regimens, administered from 16 to 24 weeks, and included individually or combined PTH, alendronate (ALN), zoledronate (ZOL), and raloxifene (RAL). Anabolic therapeutic efficacy generally corresponded with PTH + RAL = PTH + ZOL > PTH + ALN = PTH > vehicle control. Loss of Nmp4 enhanced femoral trabecular bone increases under PTH + RAL and PTH + ZOL. RAL and ZOL promoted bone restoration, but unexpectedly, loss of Nmp4 boosted RAL-induced increases in femoral trabecular bone. The combination of PTH, RAL, and loss of Nmp4 significantly increased bone marrow osteoprogenitor number, but did not affect adipogenesis or osteoclastogenesis. RAL, but not ZOL, increased osteoprogenitors in both genotypes. Nmp4 status did not influence bone serum marker responses to treatments, but Nmp4-/- mice as a group showed elevated levels of the bone formation marker osteocalcin. We conclude that the heightened osteoanabolism of the Nmp4-/- skeleton enhances the effectiveness of diverse osteoporosis treatments, in part by increasing hyperanabolic osteoprogenitors. Nmp4 provides a promising target pathway for identifying barriers to pharmacologically induced bone formation.

Inhibition of IL-6/STAT3 signaling in human cancer cells using Evista

Persistent activation of IL-6/STAT3 signaling pathway has been frequently detected in human cancer including breast cancer, colon cancer and multiple myeloma. IL-6/STAT3 can be a promising target for cancer prevent and treatment. However, few STAT3 inhibitors with high efficiency, specificity and safety is available for present clinical cancer therapy. Evista (Raloxifene·HCl) is known as selective estrogen receptor modulator which has been used for the prevention and treatment of osteoporosis and was approved for reducing the risk of invasive breast cancer. Our previous study found that Raloxifene inhibited IL-6/GP130 interaction, resulting in blockade of STAT3 phosphorylation. In our present study, we examined the effect on IL-6/GP130/STAT3 signaling pathway and cancer cell viability with Evista. We first demonstrated Evista inhibited constitutive activation of STAT3 in breast cancer cell line MDB-MB-231, colon cancer cell line HCT116 and multiple myeloma cancer cell line U266. Evista also inhibited phosphorylation of STAT3 induced by IL-6 in MCF-7, HT29 and MM.1S cancer cell lines. Induction of apoptosis was exerted in MDA-MB-231, HCT116 and U266 as evidenced by increased caspase-3 cleavage. However, Evista did not inhibit STAT1, STAT2, STAT4 or STAT6 phosphorylation elicited by IFN-α, IFN-γ and IL-4, nor phosphorylation of STAT3 induced by LIF in MCF-7 cell lines. Evista attenuated STAT3 phosphorylation, decreased STAT3 transcriptional activity but much less in pGL3 and AP1 transcriptional luciferase activity, and decreased cell viability in vitro. These results suggest that it may be possible for Evista to emerge as a chemoprevention agent for breast cancer and other cancers such as colon cancer or multiple myeoloma by targeting IL-6/STAT3 signaling.

Effects of raloxifene and alendronate on non-enzymatic collagen cross-links and bone strength in ovariectomized rabbits in sequential treatments after daily human parathyroid hormone (1-34) administration

This study investigated the effects of raloxifene and alendronate to follow parathyroid hormone (PTH) on bone collagen and biomechanical properties in ovariectomized rabbits. Sequential treatments of raloxifene and alendronate after hPTH(1-34) treatment improved biomechanical properties with and without bone collagen improvement, respectively.

INTRODUCTION

The standard sequential treatment to follow human parathyroid hormone (hPTH) (1-34) therapy for osteoporosis has yet to be determined. The objective of this study was to compare the effects of raloxifene and alendronate treatments to follow daily hPTH(1-34) treatment on non-enzymatic collagen cross-links, bone mass, and bone strength in ovariectomized (OVX) rabbits.

METHODS

From 3 months after ovariectomy, seven month-old female New Zealand white rabbits were given either vehicle or hPTH(1-34) (8 μg/kg/day), once daily for 5 months. After hPTH(1-34) treatment, the hPTH(1-34)-treated animals were divided into two groups, and given raloxifene (10 mg/kg, daily) orally or alendronate (100 μg/kg, twice weekly) subcutaneously for 5 months. We evaluated bone mineral density (BMD), bone structural parameters, advanced glycation end product (AGE) content in collagen, and bone mechanical parameters including intrinsic parameters in the femur.

RESULTS

Raloxifene (hPTH/RLX) and alendronate (hPTH/ALN) to follow hPTH(1-34) increased cortical thickness, maximum load, and maximum stress and decreased endocortical surface in the diaphysis, in addition to increasing total BMD in the distal metaphysis. Decreased trabecular AGE, pentosidine, and homocysteine contents and increased toughness and breaking energy were noted with hPTH/RLX treatment only. With hPTH/ALN treatment, no effects on non-enzymatic collagen cross-link AGEs were noted although increases in stiffness and elastic modulus were observed.

CONCLUSION

These results suggest that sequential treatments with hPTH(1-34) and antiresorptive drugs (raloxifene and alendronate) have a beneficial effect on bone mass and biomechanical properties in OVX rabbits.

Preventive effects of raloxifene treatment on agerelated weight loss in postmenopausal women

Decline of body weight and body mass index (BMI) with aging is a major risk factor for osteoporosis and fracture, suggesting that treatment for osteoporosis may affect body composition. However, the effects of treatment for osteoporosis on body composition are not well known. The present study aimed to identify the relationship between raloxifene treatment and body composition markers. We measured bone mineral density (BMD), body composition, and bone remodeling markers in 236 Japanese postmenopausal women with raloxifene treatment (N = 50) and without treatment by any osteoporosis drug (N = 186) for 5 years and analyzed the relationship of these with BMD, BMI, body weight, and biochemical markers. The mean (SD) age of the participants was 65.5 (9.3) years. Percent-changes in body weight and BMI were significantly different between women taking raloxifene and those not taking any osteoporosis drugs (P = 0.03 and 0.048, respectively). Raloxifene treatment was a significant independent determinant of body weight and BMI. Long-term treatment with raloxifene prevents age-related weight loss.

Ovariectomy-Induced Mitochondrial Oxidative Stress, Apoptosis, and Calcium Ion Influx Through TRPA1, TRPM2, and TRPV1 Are Prevented by 17β-Estradiol, Tamoxifen, and Raloxifene in the Hippocampus and Dorsal Root Ganglion of Rats

Relative 17β-estradiol (E2) deprivation and excessive production of mitochondrial oxygen free radicals (OFRs) with a high amount of Ca²⁺ influx TRPA1, TRPM2, and TRPV1 activity is one of the main causes of neurodegenerative disease in postmenopausal women. In addition to the roles of tamoxifen (TMX) and raloxifene (RLX) in cancer and bone loss treatments, regulator roles in Ca²⁺ influx and mitochondrial oxidative stress in neurons have not been reported. The aim of this study was to evaluate whether TMX and RLX interactions with TRPA1, TRPM2, and TRPV1 in primary hippocampal (HPC) and dorsal root ganglion (DRG) neuron cultures of ovariectomized (OVX) rats. Forty female rats were divided into five groups: a control group, an OVX group, an OVX+E2 group, an OVX+TMX group, and an OVX+RLX group. The OVX+E2, OVX+TMX, and OVX+RLX groups received E2, TMX, and RLX, respectively, for 14 days after the ovariectomy. E2, ovariectomy-induced TRPA1, TRPM2, and TRPV1 current densities, as well as accumulation of cytosolic free Ca²⁺ in the neurons, were returned to the control levels by E2, TMX, and RLX treatments. In addition, E2, TMX, and RLX via modulation of TRPM2 and TRPV1 activity reduced ovariectomy-induced mitochondrial membrane depolarization, apoptosis, and cytosolic OFR production. TRPM2, TRPV1, PARP, and caspase-3 and caspase-9 expressions were also decreased in the neurons by the E2, TMX, and RLX treatments. In conclusion, we first reported the molecular effects of E2, TMX, and RLX on TRPA1, TRPM2, and TRPV1 channel activation in the OVX rats. In addition, we observed neuroprotective effects of E2, RLX, and TMX on oxidative and apoptotic injuries of the hippocampus and peripheral pain sensory neurons (DRGs) in the OVX rats. Graphical Abstract Possible molecular pathways of involvement of DEX in cerebral ischemia-induced apoptosis, oxidative stress, and calcium accumulation through TRPA1, TRPM2 and TRPV1 in the hippocampus and DRG neurons of rats. The N domain of the TRPM2 contains ADP-ribose (ADPR) pyrophosphate enzyme, which is separately activated by ADPR and oxidative stress, although the channel is reversibly inhibited by N-(p-amylcinnamoyl) anthranilic acid (ACA). The TRPV1 is also activated by mitochondrial oxidative stress and capsaicin, and it is blocked by capsazepine (CPZ). TRPA1 is also activated by oxidative stress it is inhibited by AP18. Increased cytosolic Ca²⁺ concentration through TRPA1, TRPM2 and TRPV1 in ovariectomized (OVX) rats may lead to neuronal toxicity, reactive oxygen species (ROS) processes, and eventual cell death. 17β-Estradiol (E2), tamoxifen (TMX), and raloxifene (RLX) reduced oxidative stress, apoptosis (including caspase-3 and caspase-9), mitochondrial membrane depolarization, and Ca²⁺ influx through the inhibition of TRPA1, TRPM2 and TRPV1 activation.

Raloxifene-/raloxifene-poly(ethylene glycol) conjugate-loaded microspheres: A novel strategy for drug delivery to bone forming cells

Raloxifene (Ral)- or Ral-poly(ethylene glycol) (PEG) conjugate-loaded microspheres were prepared with poly(ε-caprolactone) (PCL) alone or with the blend of PCL and poly(D,L-lactide-co-glycolide) (PLGA) to provide controlled and sustained Ral release systems. Benefits of these formulations were evaluated on bone regeneration. Ral-loaded PCL microspheres had the highest encapsulation efficiency (70.7±5.0%) among all groups owing to high hydrophobic natures of both Ral and PCL. Cumulative amount of Ral released from Ral-PEG (1:2) conjugate-loaded PCL:PLGA (1:1) microspheres (26.9±8.8%) after 60days was significantly higher relative to other microsphere groups. This finding can be ascribed to two factors: i) Ral-PEG conjugation, resulting in increased water-solubility of Ral and increased degradation rates of PCL and PLGA with enhanced water penetration into the polymer matrix, and ii) usage of PLGA besides PCL in the carrier composition to benefit from less hydrophobic and faster degradable nature of PLGA in comparison to PCL. In vitro cytotoxicity studies performed using adipose-derived mesenchymal stem cells (ASCs) demonstrated that all microspheres were non-toxic. Evaluation of intensities of Alizarin red S staining conducted after 7 and 14days of incubation of ASCs in the release media of the different microsphere groups was performed with Image J analysis software. At day 7, it was observed that the matrix deposited by the cells cultivated in the release medium of Ral-PEG (1:2) conjugate-loaded PCL:PLGA (1:1) microspheres had significantly higher mineral content (26.78±6.23%) than that of the matrix deposited by the cells cultivated in the release media of the other microsphere groups except Ral-loaded PCL:PLGA (1:1) microsphere group. At day 14, Ral release from Ral-PEG (1:2) conjugate-loaded PCL:PLGA (1:1) microsphere group resulted with significantly higher mineralization of the matrix (32.31±1.85%) deposited by ASCs in comparison to all other microsphere groups. Alizarin red S staining results eventuated in parallel with the release results. Thus, it can be suggested that Ral-PEG (1:2) conjugate-loaded PCL:PLGA (1:1) microsphere formulation has a potential as an effective controlled drug delivery system for bone regeneration.

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.