Osteoporosis - a current view of pharmacological prevention and treatment

Cost-effectiveness analysis of surgical proximal femur fracture prevention in elderly: a Markov cohort simulation model

BACKGROUND

Hip fractures are a common and costly health problem, resulting in significant morbidity and mortality, as well as high costs for healthcare systems, especially for the elderly. Implementing surgical preventive strategies has the potential to improve the quality of life and reduce the burden on healthcare resources, particularly in the long term. However, there are currently limited guidelines for standardizing hip fracture prophylaxis practices.

METHODS

This study used a cost-effectiveness analysis with a finite-state Markov model and cohort simulation to evaluate the primary and secondary surgical prevention of hip fractures in the elderly. Patients aged 60 to 90 years were simulated in two different models (A and B) to assess prevention at different levels. Model A assumed prophylaxis was performed during the fracture operation on the contralateral side, while Model B included individuals with high fracture risk factors. Costs were obtained from the Centers for Medicare & Medicaid Services, and transition probabilities and health state utilities were derived from available literature. The baseline assumption was a 10% reduction in fracture risk after prophylaxis. A sensitivity analysis was also conducted to assess the reliability and variability of the results.

RESULTS

With a 10% fracture risk reduction, model A costs between $8,850 and $46,940 per quality-adjusted life-year ($/QALY). Additionally, it proved most cost-effective in the age range between 61 and 81 years. The sensitivity analysis established that a reduction of ≥ 2.8% is needed for prophylaxis to be definitely cost-effective. The cost-effectiveness at the secondary prevention level was most sensitive to the cost of the contralateral side's prophylaxis, the patient's age, and fracture treatment cost. For high-risk patients with no fracture history, the cost-effectiveness of a preventive strategy depends on their risk profile. In the baseline analysis, the incremental cost-effectiveness ratio at the primary prevention level varied between $11,000/QALY and $74,000/QALY, which is below the defined willingness to pay threshold.

CONCLUSION

Due to the high cost of hip fracture treatment and its increased morbidity, surgical prophylaxis strategies have demonstrated that they can significantly relieve the healthcare system. Various key assumptions facilitated the modeling, allowing for adequate room for uncertainty. Further research is needed to evaluate health-state-associated risks.

A comprehensive review of the health benefits of flaxseed oil in relation to its chemical composition and comparison with other omega-3-rich oils

Flaxseed (Linum usitatissimum L) is an ancient perennial plant species regarded as a multipurpose plant owing to its richness in omega-3 polyunsaturated fatty acids (PUFA) including α-linolenic acid (ALA). The extensive biochemical analysis of flaxseed resulted in the identification of its bioactive, i.e., lignans with potential application in the improvement of human health. Flaxseed oil, fibers, and lignans exert potential health benefits including reduction of cardiovascular disease, atherosclerosis, diabetes, cancer, arthritis, osteoporosis, and autoimmune and neurological disorders that have led to the diversification of flaxseed plant applications. This comprehensive review focuses on flaxseed oil as the major product of flaxseed with emphasis on the interrelationship between its chemical composition and biological effects. Effects reviewed include antioxidant, anti-inflammatory, antimicrobial, anticancer, antiulcer, anti-osteoporotic, cardioprotective, metabolic, and neuroprotective. This study provides an overview of flaxseed oil effects with the reported action mechanisms related to its phytochemical composition and in comparison, to other PUFA-rich oils. This study presents the most updated and comprehensive review summarizing flaxseed oil's health benefits for the treatment of various diseases.

A narrative review of the pharmaceutical management of osteoporosis

Background and Objective

Osteoporosis is a skeletal disorder classified by the loss of bone density in older adults leading to compromised bone strength and an increased risk of fracture. It can be divided into categories based on its etiology: senile, post-menopausal, and secondary osteoporosis. Specific prevention measures and treatments exist for targeting bone loss. Here we review and summarize the literature regarding the presentation of osteoporosis and discuss pharmaceutical therapies.

Methods

PubMed and Google Scholar were searched for articles published in English between 1980 and 2021. Search terms combined "senile osteoporosis", "osteoporosis treatment", "osteoporosis", "bisphosphonates", "denosumab", types of hormone therapy, and other relevant keywords used in various combinations.

Key Content and Findings

Osteoporosis affects millions but often goes undiagnosed until a pathologic fracture. Dual-energy X-ray absorptiometry (DEXA) scans evaluate bone mineral density (BMD) and are a diagnostic tool for osteoporosis. Adults over the age of 65, post-menopausal women, and those with risk factors such as previous fractures are recommended to receive DEXA scans every one to two years. Bisphosphonates, denosumab, and hormonal therapies are among the most common pharmacologic treatments for osteoporosis.

Conclusions

Daily, orally administered bisphosphonates are the first-line therapy for osteoporosis given their efficacy in decreasing fracture risk and favorable safety profile. Denosumab is an alternative that is administered subcutaneously every six months and may be given as initial therapy to select patients. Hormonal therapies are used if patients cannot tolerate bisphosphonates or denosumab or are refractory to these medications. Preventative measures for osteoporosis include tailored exercise and sufficient intake of calcium and vitamin D via diet or supplementation.

Tetracyclic Steroids Bearing a Bicyclo[4.4.1] Ring System as Potent Antiosteoporosis Agents from the Deep-Sea-Derived Fungus Rhizopus sp. W23

Chemical investigation of the deep-sea-derived fungus Rhizopus sp. W23 resulted in the identification of six new (1-3, 6, 8, 9) and 12 known (4, 5, 10-19) cyclocitrinol analogues, together with one handling artifact (7), all featuring an unusual 7/7/6/5-tetracyclic scaffold and bicyclo[4.4.1] A/B rings. Norcyclocitrinoic acids A and B (1, 2) represent the second occurrence of 24,25-bisnor cyclocitrinols. Structures were assigned to new steroids on the basis of extensive spectroscopic analysis and X-ray crystallography. Compound 13 significantly enhances osteoblastogenesis and inhibits adipogenesis in mature bone marrow stromal cells at 5 μM, indicating a potential to be an antiosteoporosis lead.

Association between Serum Cystatin C levels and long‐term cardiovascular outcomes and all-cause mortality in older patients with obstructive sleep apnea

Background and Aims: To investigate the association between obstructive sleep apnea (OSA) severity and baseline serum cystatin C (Cys-C) concentration and to explore the association between baseline serum Cys-C and long-term cardiovascular outcomes and mortality in older patients with OSA.

Methods: Between January 2015 and October 2017, a total of 1107 consecutive eligible older patients (≥60 years) with OSA were included in this multicenter, prospective cohort study, and baseline demographics, clinical characteristics, sleep parameters, and follow-up outcomes were collected. Participants were divided into different groups based on baseline serum Cys-C levels. The primary end point was major adverse cardiovascular events (MACE) and the secondary end point was all-cause mortality. The correlation between OSA severity and baseline serum Cys-C was evaluated by Spearman correlation analysis. Multivariate Cox regression was used to analyze the association between Cys-C and the incidence of MACE and mortality.

Results: Participants included 672 men and 435 women, with a median age of 66 (range, 60–96) years. At baseline, apnea–hypopnea index (AHI) (r = 0.128, p < 0.05), oxygen desaturation index (ODI) (r = 0.116, p < 0.05), and the lowest pulse oxygen saturation (LSpO2) (r = −0.097, p < 0.05) were correlated with serum Cys-C concentration. During the median follow-up period of 42 months, 97 patients (8.8%) experienced MACE and 40 patients (3.6%) experienced death. The association between serum Cys-C levels and the risk of MACE and all-cause mortality was slow rising shaped. The multivariable Cox regression analysis showed patients with a serum Cys-C concentration of ≥1.14 mg/L had higher risks of MACE (HR = 5.30, 95% CI: 2.28–12.30, p < 0.05) and all-cause mortality (HR = 9.66, 95% CI: 2.09–44.72, p < 0.05) compared with patients with serum Cys-C of ≤0.81 mg/L in older patients with OSA. The receiver-operating characteristic curve showed baseline serum Cys-C levels exhibited moderately capable of identifying patients with a long-term risk of clinical adverse events (MACE and mortality).

Conclusion: OSA severity was positively correlated with serum Cys-C concentration. High levels of Cys-C were independently associated with increased risks of MACE and all-cause mortality in older patients with OSA, suggesting that lowering Cys-C levels should be considered as a therapeutic target, and monitoring serum Cys-C may be beneficial to the favorable prognosis of older patients with OSA.

Disease-Associated Regulation of Non-Coding RNAs by Resveratrol: Molecular Insights and Therapeutic Applications

There have been significant advances, particularly over the last 20 years, in the identification of non-coding RNAs (ncRNAs) and their pathophysiological role in a wide range of disease states, particularly cancer and other chronic conditions characterized by excess inflammation and oxidative stress such as atherosclerosis, diabetes, obesity, multiple sclerosis, osteoporosis, liver and lung fibrosis. Such discoveries have potential therapeutic implications as a better understanding of the molecular mechanisms underpinning the effects of ncRNAs on critical homeostatic control mechanisms and biochemical pathways might lead to the identification of novel druggable targets. In this context, increasing evidence suggests that several natural compounds can target ncRNAs at different levels and, consequently, influence processes involved in the onset and progression of disease states. The natural phenol resveratrol has been extensively studied for therapeutic purposes in view of its established anti-inflammatory and antioxidant effects, particularly in disease states such as cancer and cardiovascular disease that are associated with human aging. However, increasing in vitro and in vivo evidence also suggests that resveratrol can directly target various ncRNAs and that this mediates, at least in part, its potential therapeutic effects. This review critically appraises the available evidence regarding the resveratrol-mediated modulation of different ncRNAs in a wide range of disease states characterized by a pro-inflammatory state and oxidative stress, the potential therapeutic applications, and future research directions.

Pharmacological and Non-Pharmacological Agents versus Bovine Colostrum Supplementation for the Management of Bone Health Using an Osteoporosis-Induced Rat Model

Osteoporosis is defined by loss of bone mass and deteriorated bone microarchitecture. The present study compared the effects of available pharmacological and non-pharmacological agents for osteoporosis [alendronate (ALE) and concomitant supplementation of vitamin D (VD) and calcium (Ca)] with the effects of bovine colostrum (BC) supplementation in ovariectomized (OVX) and orchidectomized (ORX) rats. Seven-month-old rats were randomly allocated to: (1) placebo-control, (2) ALE group (7.5 μg/kg of body weight/day/5 times per week), (3) VD/Ca group (VD: 35 μg/kg of body weight/day/5 times per week; Ca: 13 mg/kg of body weight/day/3 times per week), and (4) BC supplementation (OVX: 1.5 g/day/5 times per week; ORX: 2 g/day/5 times per week). Following four months of supplementation, bone microarchitecture, strength and bone markers were evaluated. ALE group demonstrated significantly higher Ct.OV, Ct.BMC, Tb.Th, Tb.OV and Tb.BMC and significantly lower Ct.Pr, Tb.Pr, Tb.Sp, Ct.BMD and Tb.BMD, compared to placebo (p < 0.05). BC presented significantly higher Ct.Pr, Ct.BMD, Tb.Pr, Tb.Sp, and Tb.BMD and significantly lower Ct.OV, Ct.BMC, Tb.Th, Tb.OV and Tb.BMC compared to ALE in OVX rats (p < 0.05). OVX rats receiving BC experienced a significant increase in serum ALP and OC levels post-supplementation (p < 0.05). BC supplementation may induce positive effects on bone metabolism by stimulating bone formation, but appear not to be as effective as ALE.

Uncovering Hidden Mechanisms of Different Prescriptions Treatment for Osteoporosis via Novel Bioinformatics Model and Experiment Validation

Osteoporosis (OP) is a systemic disease susceptible to fracture due to the decline of bone mineral density and bone mass, the destruction of bone tissue microstructure, and increased bone fragility. At present, the treatments of OP mainly include bisphosphonates, hormone therapy, and RANKL antibody therapy. However, these treatments have observable side effects and cannot fundamentally improve bone metabolism. Currently, the prescription of herbal medicine and their derived proprietary Chinese medicines are playing increasingly important roles in the treatment of OP due to their significant curative effects and few side effects. Among these prescriptions, Gushukang Granules (GSK), Xianling Gubao Capsules (XLGB), and Er-xian Decoction (EXD) are widely employed at the clinic on therapy of OP, which also is in line with the compatibility principle of “different treatments for the same disease” in herbal medicine. However, at present, the functional interpretation of “different treatments for the same disease” in herbal medicine still lacks systematic quantitative research, especially on the detection of key component groups and mechanisms. To solve this problem, we designed a new bioinformatics model based on random walk, optimized programming, and information gain to analyze the components and targets to figure out the Functional Response Motifs (FRMs) of different prescriptions for the therapy of OP. The distribution of high relevance score, the number of reported evidence, and coverage of enriched pathways were performed to verify the precision and reliability of FRMs. At the same time, the information gain and target influence of each component was calculated, and the key component groups in all FRMs of each prescription were screened to speculate the potential action mode of different prescriptions on the same disease. Results show that the relevance score and the number of reported evidence of high reliable genes in FRMs were higher than those of the pathogenic genes of OP. Furthermore, the gene enrichment pathways in FRMs could cover 79.6, 81, and 79.5% of the gene enrichment pathways in the component-target (C-T) network. Functional pathway enrichment analysis showed that GSK, XLGB, and EXD all treat OP through osteoclast differentiation (hsa04380), calcium signaling pathway (hsa04020), MAPK signaling pathway (hsa04010), and PI3K-Akt signaling pathway (hsa04151). Combined with experiments, the key component groups and the mechanism of “different treatments for the same disease” in the three prescriptions and proprietary Chinese medicines were verified. This study provides methodological references for the optimization and mechanism speculation of Chinese medicine prescriptions and proprietary Chinese medicines.

Relationship of Bone Turnover Markers with Serum Uric Acid-to-Creatinine Ratio in Men and Postmenopausal Women with Type 2 Diabetes

PURPOSE

Accumulating evidence has shown that serum uric acid (UA) is associated with some chronic diseases owing to its antioxidant capacity; however, previous research has discrepant results regarding the relationship between UA and bone health. UA normalized by renal function can reflect endogenous UA levels more precisely than SUA levels. This study assessed the relationship between serum UA-to-creatinine (SUA/Cr) ratio and bone turnover markers (BTMs) in men and postmenopausal women with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

Overall, 1691 patients (1028 males and 663 postmenopausal females) with T2DM admitted to Hebei General Hospital between January and December 2020 were selected and divided into two groups according to their SUA/Cr ratio. One-way analysis of variance was used to compare groups. The relationship between the SUA/Cr ratio and BTMs (including osteocalcin [OC], procollagen I N-terminal peptide [PINP], and β-isomerized type I collagen C-telopeptide breakdown products [β-CTX]) was analyzed using multiple linear regression. Furthermore, subgroup analyses were performed to explore the differences between men and women in the relationship between SUA/Cr and BTMs. Mediation analysis was used to explore whether insulin resistance mediated the association between SUA/Cr and BTMs.

RESULTS

β-CTX and PNIP levels of patients with T2DM in the low SUA/Cr group were significantly higher than those in the high SUA/Cr group, and the difference between the two groups was statistically significant (P < 0.05). Correlation analysis showed that SUA/Cr was negatively correlated with β-CTX and PNIP. After adjusting for confounding factors, multivariate linear regression analysis revealed that the SUA/Cr level was negatively correlated with PINP and β-CTX in male patients and postmenopausal women with T2DM. Stronger correlations were found in patients with 25(OH)D3 < 20ng/mL, course ≥ 5 years, HbA1c > 7%, or BMI < 28 kg/m2.

CONCLUSION

SUA/Cr ratio was an independent influencing factor of BTMs in patients with T2DM.

Assessment of the importance of physical activity and quality of life for patients diagnosed with osteoporosis during the COVID-19 pandemic

Introduction. Osteoporosis is one of the most important ten diseases worldwide, still causing extreme suffering to patients and huge costs to the health system. The rapid increase of the population 's aging was involved in many aspects of human health, and, among these ones, osteoporosis was one of the main public health issues. The aim of the study was to assess the importance of physical activity and the quality of life in patients diagnosed with osteoporosis during the COVID-19 pandemic. Material and methods. The study is longitudinal, it was conducted in an outpatient setting for a period of 1 year and it included 20 patients diagnosed with osteoporosis. The demographic variables (age, living environment, body mass index) were assessed, and as parameters: pain (VAS scale), fracture risk (FRAX score), quality of life (Qualeffo-41 questionnaire), bone mineral density at the spine and at the femur (DEXA). The patients received pharmacological treatment such as bisphosphonates and underwent physiotherapy for pains: low frequency currents (TENS), ultrasound and physical therapy. Results and discussions. In all the studied cases, it was considered that the pain decreased following the use of the medicinal and physiotherapeutic treatment. This is an expected result given that other studies have shown this. Postmenopausal women in Romania with osteoporosis have a lower HRQoL than healthy controls, measured with the SF-36 instrument and the total QUALEFFO-41 score. Conclusions. The obtained data point out the correlation between bone mineral density, fracture risks and exercises in patients diagnosed with osteoporosis. The FRAX score is useful to identify patients who need the combination of drug therapy and exercises to prevent vertebral and non-vertebral fractures in the next 10 years. Keywords: osteoporosis, physical activity, quality of life, COVID-19,

Mesenchymal Stem Cell-Derived Extracellular Vesicles Inhibit Osteoporosis via MicroRNA-27a-Induced Inhibition of DKK2-Mediated Wnt/β-Catenin Pathway

Osteoporosis (OP) is a systemic skeletal disease that promotes bone fragility and the risk of fractures. Recent studies have shown the relevance of microRNAs (miRNAs) in the development of OP. This study aimed to evaluate the possible mechanisms of action underlying miR-27a loaded by mesenchymal stem cell (MSC)-derived extracellular vesicles (MSC-EVs) in OP. Serum samples from OP patients and normal controls were collected for miRNA microarray analysis. The expression of filtered miRNA was upregulated in osteoblasts (OB) and osteoclasts (OCs) for biological activity assessment. After developing OP mice using ovariectomy (OVX) and confirming OP, the miR-27a expression level was upregulated in mice by MSC-EV application. Dual-luciferase assays were conducted to validate the relationship between miR-27a and DKK2 expression. The poor expression of miR-27a was observed in patients with OP. miR-27a increased the expression of OB markers, the number of ALP-positive cells, and the number of calcium nodules in OCs. In OVX mice, miR-27a increased bone density, improved bone structure damage recovery, decreased the levels of bone resorption markers, and decreased OC number. miR-27a transmitted by MSC-EVs interacted with DKK2. MSC-EVs exerted the same protective effects as miR-27a on OP, whereas miR-27a inhibitor abolished the attenuating effects of MSC-EVs. In contrast, DKK2 depletion reversed the stimulatory effects of the miR-27a inhibitor on OP. The Wnt/β-catenin pathway was activated upon MSC-EV application and DKK2 silencing and was impaired upon the downregulation of the expression of miR-27a. MSC-EVs are effective in preventing mouse OP. This mechanism is mediated by the miR-27a/DKK2/Wnt/β-catenin signaling pathway.

Osteoporosis therapies and their mechanisms of action (Review)

Osteoporosis is a common disease that affects millions of patients worldwide and is most common in menopausal women. The main characteristics of osteoporosis are low bone density and increased risk of fractures due to deterioration of the bone architecture. Osteoporosis is a chronic disease that is difficult to treat; thus, investigations into novel effective therapeutic methods are required. A number of studies have focused on determining the most effective treatment options for this disease. There are several treatment options for osteoporosis that differ depending on the characteristics of the disease, and these include both well-established and newly developed drugs. The present review focuses on the various drugs available for osteoporosis, the associated mechanisms of action and the methods of administration.

Anti-Osteoporotic Activity of Pueraria lobata Fermented with Lactobacillus paracasei JS1 by Regulation of Osteoblast Differentiation and Protection against Bone Loss in Ovariectomized Mice

Osteoporosis is the most common bone disease associated with low bone mineral density. It is the process of bone loss and is most commonly caused by decreased estrogen production in women, particularly after menopause. Pueraria lobata, which contains various metabolites, especially isoflavone, is widely known as regulator for bone mineral contents. In this study, the effects of the P. lobata extract (PE) with or without fermentation with Lactobacillus paracasei JS1 (FPE) on osteoporosis were investigated in vitro and in vivo. The effects of PE and FPE on human osteoblastic MG63 cells, RAW 264.7 cells, and ovariectomized (OVX)-induced model mice were analyzed at various ratios. We found that FPE increased calcium deposition and inhibited bone resorption by in vitro assay. Furthermore, treatment with PE and FPE has significantly restored destroyed trabecular bone in the OVX-induced bone loss mouse model. Overall, FPE demonstrated bioactivity to prevent bone loss by decreasing bone turnover.

Bovine Colostrum Supplementation Improves Bone Metabolism in an Osteoporosis-Induced Animal Model

Osteoporosis is characterized by bone loss. The present study aims to investigate the effects of bovine colostrum (BC) on bone metabolism using ovariectomized (OVX) and orchidectomized (ORX) rat models. Twenty-seven-week-old Wistar Han rats were randomly assigned as: (1) placebo control, (2) BC supplementation dose 1 (BC1: 0.5 g/day/OVX, 1 g/day/ORX), (3) BC supplementation dose 2 (BC2: 1 g/day/OVX, 1.5 g/day/ORX) and (4) BC supplementation dose 3 (BC3: 1.5 g/day/OVX, 2 g/day/ORX). Bone microarchitecture, strength, gene expression of VEGFA, FGF2, RANKL, RANK and OPG, and bone resorption/formation markers were assessed after four months of BC supplementation. Compared to the placebo, OVX rats in the BC1 group exhibited significantly higher cortical bone mineral content and trabecular bone mineral content (p < 0.01), while OVX rats in the BC3 group showed significantly higher trabecular bone mineral content (p < 0.05). ORX rats receiving BC dose 2 demonstrated significantly higher levels of trabecular bone mineral content (p < 0.05). Serum osteocalcin in the ORX was pointedly higher in all BC supplementation groups than the placebo (BC1: p < 0.05; BC2, BC3: p < 0.001). Higher doses of BC induced significantly higher relative mRNA expression of OPG, VEGFA, FGF2 and RANKL (p < 0.05). BC supplementation improves bone metabolism of OVX and ORX rats, which might be associated with the activation of the VEGFA, FGF2 and RANKL/RANK/OPG pathways.

Coordination Compounds As Multi-Delivery Systems for Osteoporosis

Osteoporosis therapies leveraging bisphosphonates and mineral components (e.g., magnesium, calcium, and strontium) have been raising attention because of their potential for managing this ever-growing disease. The administration of multicomponent therapeutics (combined therapy) in elderly patients is complex and suffers from low patient adherence. Herein, we report an all-in-one combination of four antiosteoporotic components into a new family of coordination complexes: [M₂(H₄alen)₄(H₂O)₂]·1.5H₂O [where M²⁺ = Mg²⁺ (1), (Mg_0.535Ca_0.465)²⁺ (2) and (Mg_0.505Ca_0.450Sr_0.045)²⁺ (3)]. These solid-state complexes were prepared, for the first time, through microwave-assisted synthesis. It is demonstrated that the compounds are capable of releasing their antiosteoporotic components, both in conditions that mimic the path along the gastrointestinal tract and in long periods under physiological conditions (pH ∼7.4). More importantly, when administered in low concentrations, the compounds did not elicit a cytotoxic effect toward liver, kidney, and osteoblast-like cell lines. Besides, it is important to highlight the unique coordination complex with four bone therapeutic components, [(Mg_0.505Ca_0.450Sr_0.045)₂(H₄alen)₄(H₂O)₂]·1.5H₂O (3), which significantly promoted osteoblast metabolic activity up to ca. 1.4-fold versus the control group. These findings bring this type of compounds one-step closer to be considered as an all-in-one and more effective treatment for managing chronic bone diseases, prompting further research on their therapeutic properties.

The Relationship Between Fragility Fractures and Pain Experience: A Systematic Review

Purpose: This systematic review is conducted to explore the relationship between fragility fractures and pain experience.

Methods: We searched for relevant studies on Pubmed, Embase, Web of Science, and the Cochrane library without restrictions on language from inception until February 4th, 2021. The risk of bias and methodological quality was evaluated using the Newcastle-Ottawa Scale and ROBINS-I tool.

Results: Twenty-one studies were included in this systematic review. The so-called study reported participants with continuous post-fracture pain. The included studies showed that post- fractured pain can decrease with time, however, the continual pain can last at least 1 year even longer, and some participants would need to self-manage pain. Moreover, the limited range of motion was considered as a factor that might distress the normal development of daily activities.

Conclusions: The current evidence could not fully support that pain continues to influence patients' lives after a fragility fracture. However, it still showed the pain might come with fracture. The findings also could be useful to help health care providers better recognize and manage this clinical consequence of fractures. Nonetheless, future large-scale longitudinal studies will be required to evaluate the long-term effects of pain in fragility fractures.

The Effect of Polybutylcyanoacrylate Nanoparticles as a Protos Delivery Vehicle on Dental Bone Formation

BACKGROUND

Dental implants are commonly used for missing teeth, for which success depends heavily on the quality of the alveolar bone. The creation of an ideal implant site is a key component in shortening the treatment time, which remains clinically challenging. Strontium ranelate (Protos) is an anti-osteoporotic agent which has previously been used to promote bone formation, however the systemic use of Protos has been linked to serious cardiovascular and venous thromboembolic events, thus local delivery strategies may be better suited for this purpose. In this study, a biodegradable, and biocompatible nanocarrier "polybutylcyanoacrylate" (PBCA) loaded with strontium was constructed and its ability to promote bone formation was assessed.

METHODOLOGY

PBCA nanoparticles loaded with strontium (PBCA-Sr NPs) were synthesized using the emulsion polymerization method, and their physical properties (zeta potential, size and shape) and entrapment efficiency were characterized. Committed MSCs (osteoblasts) were derived from the differentiation of cultured rat mesenchymal stem cells (MSC), which were tested with the PBCA-Sr NPs for cytotoxicity, inflammatory response, bone formation and mineralization. Scanning electron microscopy was performed following a 7-day treatment of PBCA-Sr NPs on decellularized procaine mandibular bone blocks grafted with osteoblasts.

RESULTS

Spherical PBCA-Sr NPs of 166.7 ± 2.3 nm, zeta potential of -1.15 ± 0.28 mV with a strontium loading efficiency of 90.04 ± 3.27% were constructed. The presence of strontium was confirmed by energy-dispersive X-ray spectroscopy. Rat committed MSCs incubated in PBCA-Sr NPs for 24 hrs showed viabilities in excess of 90% for concentrations of up to 250 ug/mL, the cellular expression of osteocalcin and alkaline phosphatase were 1.4 and 1.3 times higher than the untreated control, and significantly higher than those treated with strontium alone. Bone formation was evident following osteoblast engraftment on the decellularized procaine mandibular bone block with PBCA-Sr NPs, which appeared superior to those treated with strontium alone.

CONCLUSION

Treatment of committed MSCs with PBCA-Sr NPs showed higher expression of markers of bone formation when compared with strontium alone and which corresponded to greater degree of bone formation observed on the 3-dimensinal decellularized procaine mandibular bone block. Further quantitative analysis on the extent of new bone formation is warranted.

Success Rate and Safety of Dental Implantology in Patients Treated With Antiresorptive Medication: A Systematic Review

There is no agreement of data on the subject of implant failure and the development of osteonecrosis in patients receiving antiresorptive agents. The purpose of this systematic review is to evaluate whether dental implants placed in patients on antiresorptive medication have an increased failure rate and whether the implant placement or the implant existence are risk factors for developing medication-related osteonecrosis of the jaw (MRONJ). An electronic search was conducted in PubMed/Medline, and all publications fulfilling the inclusion criteria were included. The search was completed by a hand research of the references cited in all electronic identified publications, resulting in 411 articles. Based on the inclusion criteria, 32 studies were included, with a total of 5221 patients, 12 751 implants, 618 cases of implants loss, and 136 cases of MRONJ analyzed. Because of the small number of studies, most of which were characterized by a low level of quality, it cannot be established that the use of antiresorptive medication affects dental implant survival rates. The risk of MRONJ as an early or late complication is also not well established. Therefore, successful dental implant procedures in patients receiving antiresorptive medication might be possible, but more studies need to be carried out in the future to verify this topic. Apart from intravenous antiresorptive drugs, which remain an absolute contraindication, the use of antiresorptive medication is not a contraindication to dental implantology, but it must be accompanied by careful treatment planning, informing patients about possible complications, and essential long follow-up periods.

Leonurine Promotes the Osteoblast Differentiation of Rat BMSCs by Activation of Autophagy via the PI3K/Akt/mTOR Pathway

Background

Leonurine, a major bioactive component from Herba leonuri, has been shown to exhibit anti-inflammatory and antioxidant effects. The aim of this study was to investigate the effect of leonurine on bone marrow-derived mesenchymal stem cells (BMSCs) as a therapeutic approach for treating osteoporosis.

Materials and Methods

Rat bone marrow-derived mesenchymal stem cells (rBMSCs) were isolated from 4-weeks-old Sprague–Dawley rats. The cytocompatibility of leonurine on rBMSCs was tested via CCK-8 assays and flow cytometric analyses. The effects of leonurine on rBMSC osteogenic differentiation were analyzed via ALP staining, Alizarin red staining, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot. Additionally, autophagy-related markers were examined via qRT-PCR and Western blot analyses of rBMSCs during osteogenic differentiation with leonurine and with or without 3-methyladenine (3-MA) as an autophagic inhibitor. Finally, the PI3K/Akt/mTOR signaling pathway was evaluated during rBMSC osteogenesis.

Results

Leonurine at 2–100 μM promoted the proliferation of rBMSCs. ALP and Alizarin red staining results showed that 10 μM leonurine promoted rBMSC osteoblastic differentiation, which was consistent with the qRT-PCR and Western blot results. Compared with those of the control group, the mRNA and protein levels of Atg5, Atg7, and LC3 were upregulated in the rBMSCs upon leonurine treatment. Furthermore, leonurine rescued rBMSC autophagy after inhibition by 3-MA. Additionally, the PI3K/AKT/mTOR pathway was activated in rBMSCs upon leonurine treatment.

Conclusion

Leonurine promotes the osteoblast differentiation of rBMSCs by activating autophagy, which depends on the PI3K/Akt/mTOR pathway. Our results suggest that leonurine may be a potential treatment for osteoporosis.

Nano-Based Biomaterials as Drug Delivery Systems Against Osteoporosis: A Systematic Review of Preclinical and Clinical Evidence

Osteoporosis (OP) is one of the most significant causes of morbidity, particularly in post-menopausal women and older men. Despite its remarkable occurrence, the search for an effective treatment is still an open challenge. Here, we systematically reviewed the preclinical and clinical progress in the development of nano-based materials as drug delivery systems against OP, considering the effects on bone healing and regeneration, the more promising composition and manufacturing methods, and the more hopeful drugs and delivery methods. The results showed that almost all the innovative nano-based delivery systems developed in the last ten years have been assessed by preclinical investigations and are still in the preliminary/early research stages. Our search strategy retrieved only one non-randomized controlled trial (RCT) on oligosaccharide nanomedicine of alginate sodium used for degenerative lumbar diseases in OP patients. Further investigations are mandatory for assessing the clinical translation and commercial purposes of these materials. To date, the main limits for the clinical translation of nano-based materials as drug delivery systems against OP are probably due to the low reproducibility of the manufacturing processes, whose specificity and complexity relies on an adequate chemical, structural, and biomechanical characterization, as the necessary prerequisite before assessing the efficacy of a given treatment or process. Finally, an unsatisfactory drug-loading capacity, an uncontrollable release kinetic, and a low delivery efficiency also limit the clinical application.

Osteoprotective Effects of Loganic Acid on Osteoblastic and Osteoclastic Cells and Osteoporosis-Induced Mice

Osteoporosis is a common disease caused by an imbalance of processes between bone resorption by osteoclasts and bone formation by osteoblasts in postmenopausal women. The roots of Gentiana lutea L. (GL) are reported to have beneficial effects on various human diseases related to liver functions and gastrointestinal motility, as well as on arthritis. Here, we fractionated and isolated bioactive constituent(s) responsible for anti-osteoporotic effects of GL root extract. A single phytochemical compound, loganic acid, was identified as a candidate osteoprotective agent. Its anti-osteoporotic effects were examined in vitro and in vivo. Treatment with loganic acid significantly increased osteoblastic differentiation in preosteoblast MC3T3-E1 cells by promoting alkaline phosphatase activity and increasing mRNA expression levels of bone metabolic markers such as Alpl, Bglap, and Sp7. However, loganic acid inhibited osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. For in vivo experiments, the effect of loganic acid on ovariectomized (OVX) mice was examined for 12 weeks. Loganic acid prevented OVX-induced bone mineral density loss and improved bone structural properties in osteoporotic model mice. These results suggest that loganic acid may be a potential therapeutic candidate for treatment of osteoporosis.

Scopolin Attenuates Osteoporotic Bone Loss in Ovariectomized Mice

Bone remodeling is a renewal process regulated by bone synthesis (osteoblasts) and bone destruction (osteoclasts). A previous study demonstrated that Lycii radicis cortex (LRC) extract inhibited ovariectomized (OVX)-induced bone loss in mice. This study investigated the anti-osteoporotic effects of bioactive constituent(s) from the LRC extract. The effective compound(s) were screened, and a single compound, scopolin, which acts as a phytoalexin, was chosen as a candidate component. Scopolin treatment enhanced alkaline phosphatase activity and increased mineralized nodule formation in MC3T3-E1 pre-osteoblastic cells. However, osteoclast differentiation in primary-cultured monocytes was reduced by treatment with scopolin. Consistently, scopolin treatment increased osteoblast differentiation in the co-culture of monocytes (osteoclasts) and MC3T3-E1 (osteoblast) cells. Scopolin treatment prevented bone mineral density loss in OVX-induced osteoporotic mice. These results suggest that scopolin could be a therapeutic bioactive constituent for the treatment and prevention of osteoporosis.

Molecular Mechanisms and Emerging Therapeutics for Osteoporosis

Osteoporosis is the most common chronic metabolic bone disease. It has been estimated that more than 10 million people in the United States and 200 million men and women worldwide have osteoporosis. Given that the aging population is rapidly increasing in many countries, osteoporosis could become a global challenge with an impact on the quality of life of the affected individuals. Osteoporosis can be defined as a condition characterized by low bone density and increased risk of fractures due to the deterioration of the bone architecture. Thus, the major goal of treatment is to reduce the risk for fractures. There are several treatment options, mostly medications that can control disease progression in risk groups, such as postmenopausal women and elderly men. Recent studies on the basic molecular mechanisms and clinical implications of osteoporosis have identified novel therapeutic targets. Emerging therapies targeting novel disease mechanisms could provide powerful approaches for osteoporosis management in the future. Here, we review the etiology of osteoporosis and the molecular mechanism of bone remodeling, present current pharmacological options, and discuss emerging therapies targeting novel mechanisms, investigational treatments, and new promising therapeutic approaches.

Discovery of Small-Molecule Inhibitors of Receptor Activator of Nuclear Factor-κB Ligand with a Superior Therapeutic Index

Receptor activator of nuclear factor-κB ligand (RANKL) constitutes the master mediator of osteoclastogenesis, while its pharmaceutical inhibition by a monoclonal antibody has been approved for the treatment of postmenopausal osteoporosis. To date, the pursuit of pharmacologically more favorable approaches using low-molecular-weight inhibitors has been hampered by low specificity and high toxicity issues. This study aimed to discover small-molecule inhibitors targeting RANKL trimer formation. Through a systematic screening of 39 analogues of SPD-304, a dual inhibitor of tumor necrosis factor (TNF) and RANKL trimerization, we identified four compounds (1b, 3b, 4a, and 4c) that selectively inhibited RANKL-induced osteoclastogenesis in a dose-dependent manner, without affecting TNF activity or osteoblast differentiation. Based on structure-activity observations extracted from the most potent and less toxic inhibitors of RANKL-induced osteoclastogenesis, we synthesized a focused set of compounds that revealed three potent inhibitors (19a, 19b, and 20a) with remarkably low cell-toxicity and improved therapeutic indexes as shown by the LC₅₀ to IC₅₀ ratio. These RANKL-selective inhibitors are an excellent starting point for the development of small-molecule therapeutics against osteolytic diseases.

The Role of Autophagy in Osteoclast Differentiation and Bone Resorption Function

Autophagy is an evolutionary conserved and highly regulated recycling process of cellular wastes. Having a housekeeping role, autophagy through the digestion of domestic cytosolic organelles, proteins, macromolecules, and pathogens, eliminates unnecessary materials and provides nutrients and energy for cell survival and maintenance. The critical role of autophagy and autophagy-related proteins in osteoclast differentiation, bone resorption, and maintenance of bone homeostasis has previously been reported. Increasing evidence reveals that autophagy dysregulation leads to alteration of osteoclast function and enhanced bone loss, which is associated with the onset and progression of osteoporosis. In this review, we briefly consolidate the current state-of-the-art technology regarding the role of autophagy in osteoclast function in both physiologic and pathologic conditions to have a more general view on this issue.

Clinical effects of switching from minodronate to denosumab treatment in patients with postmenopausal osteoporosis: a retrospective study

Background

Denosumab is a major treatment option for patients with postmenopausal osteoporosis; however, the evidence for its use is lacking. Therefore, in this 24-month retrospective study, we aimed to evaluate the effects of switching from minodronate (MIN) to denosumab in these patients.

Methods

Patients with postmenopausal osteoporosis either switched from MIN to denosumab (Group 1; n = 32) or continued MIN treatment (Group 2; n = 24). Bone mineral density (BMD) of the lumbar spine (L2–L4) and femoral neck was assessed at baseline and every 6 months for 24 months. Serum bone-specific alkaline phosphatase (BAP) and N-terminal telopeptide were measured at baseline, 12 months, and 24 months.

Results

Twenty-nine of the 32 patients (90.6%) in group 1 and all patients (24/24) in group 2 completed the 24-month follow-up. Switching from MIN to denosumab (Group 1) significantly increased lumbar BMD at 12, 18, and 24 months (6.1, 7.4, and 9.6%, respectively) and femoral neck BMD at 12, 18, and 24 months (2.8, 3.2, and 3.4%, respectively), whereas MIN continuous treatment (Group 2) showed no significant difference from baseline. Switching therapy also showed a significant decrease in serum BAP from baseline to 12 and 24 months (− 19.3 and − 26.5%, respectively) and serum NTX from baseline to 12 months (− 13.1%), whereas continuous MIN treatment failed to show any significant differences from baseline.

Conclusion

Switching from MIN to denosumab in patients with postmenopausal osteoporosis showed clinical benefits with regard to BMD and bone turnover markers in comparison with continuous MIN treatment. It may therefore be a valid treatment option in the clinical setting.

Phase II/III, randomized, double-blind, parallel-group study of monthly delayed-release versus daily immediate-release risedronate tablets in Japanese patients with involutional osteoporosis

Absorption of oral immediate-release (IR) risedronate tablets is reduced by food intake, thus a delayed-release (DR) tablet has been developed to overcome the necessity of taking IR tablets under fasting conditions. This randomized, double-blind, phase II/III study compared efficacy and safety of risedronate IR once-daily (QD) and DR once-monthly (QM) tablets in Japanese patients with involutional osteoporosis. Patients received 2.5 mg IR on awakening QD, or 25 or 37.5 mg DR on awakening, following breakfast, or 30 min after breakfast, QM for 12 months. Primary endpoint was non-inferiority in mean percent change from baseline to end of study (month 12, last observation carried forward [M12, LOCF]) in mean lumbar spine (L₂-L₄) bone mineral density (BMD) between risedronate IR on awakening and DR following breakfast. Mean percent changes in (L₂-L₄) BMD at M12, LOCF were 5.07% (IR at awakening, n = 190), 3.36% (25 mg DR following breakfast, n = 194), and 4.11% (37.5 mg DR following breakfast, n = 181). Mean percent change in (L₂-L₄) BMD was numerically lower in the DR following breakfast groups versus the respective on awakening and 30 min after breakfast DR groups. Overall incidences of treatment-emergent adverse events (TEAEs) were comparable between groups. In the DR groups, 1.5-4.0% of patients reported TEAEs potentially associated with acute-phase reactions versus 0% in the IR group. In this study, non-inferiority could not be declared for 37.5 or 25 mg DR following breakfast QM (p = 0.1346 or p = 0.6711, respectively) versus 2.5 mg IR on awakening QD.

The Role and Mechanism of SIRT1 in Resveratrol-regulated Osteoblast Autophagy in Osteoporosis Rats

Osteoporosis is widely regarded as one of the typical aging-related diseases due to the impairment of bone remodeling. The silent information regulator of transcription1 (SIRT1) is a vital regulator of cell survival and life-span. SIRT1 has been shown to be activated by resveratrol treatment, and also has been proved to prevent aging-related diseases such as osteoporosis. However, the role of SIRT1 about autophagy or mitophagy of osteoblasts in resveratrol-regulated osteoporotic rats remains unclear. This study seeks to investigate the role of SIRT1 about autophagy or mitophagy in osteoblasts through PI3K/Akt signaling pathway in resveratrol-regulated osteoporotic rats. The vivo experiment results have revealed that resveratrol treatment significantly improved bone quality and reduced the levels of serum alkaline phosphatase and osteocalcin in osteoporotic rats. Moreover, Western bolt analysis showed that expression of SIRT1, LC3, and Beclin-1 in osteoblasts increased, while p-AKT and p-mTOR were downregulated in osteoporosis rats with high dose resveratrol treatment. On the other hand, resveratrol treatment increased the SIRT1 activity, LC3 and Beclin-1 mRNA expression in the dexamethasone (DEX)-treated osteoblasts. More mitophagosomes were observed in the DEX-treated osteoblasts with resveratrol. Meanwhile, the TOM20, Hsp60, p-Akt and p-mTOR activities were decreased in the DEX-treated osteoblasts with resveratrol. Resveratrol treatment did not change the p-p38 and p-JNK activities in the osteoblasts. These results revealed that resveratrol treatment protected osteoblasts in osteoporosis rats by enhancing mitophagy by mediating SIRT1 and PI3K/AKT/mTOR signaling pathway.

Kaempferol promotes bone formation in part via the mTOR signaling pathway

Previous research indicates that kaempferol (Kae) promotes osteogenesis, but its underlying mechanism of action remains unclear. The present study hypothesized that the osteogenic effects of Kae were mediated through mammalian target of rapamycin (mTOR). To validate this hypothesis, bone marrow mesenchymal stem cells (BMSCs) from ovariectomized (OVX) rats were differentiated into osteoblasts. The bone mineral density and bone microarchitecture of the OVX rats was measured in vivo, while osteogenesis was evaluated in vitro via Alizarin Red S staining and alkaline phosphatase activity measurements in cultured BMSCs. The levels of phosphorylated eukaryotic translation initiation factor 4E‑binding protein 1 (p‑4E/BP1) and phosphorylated ribosomal protein S6 kinase B1 (p‑S6K), and the expression of Runt‑related transcription factor 2 and Osterix, were concurrently quantified by western blot analysis. The data suggested that Kae prevented OVX‑induced osteoporosis in rats by promoting osteoblastogenesis. Furthermore, treatment with Kae in rat BMSCs enhanced mineralization, elevated ALP activity, increased the expression levels of Runx‑2 and Osterix and increased the levels of p‑S6K and decreased the levels of p‑4E/BP1 and, consistent with its ability to promote osteoblast differentiation. In contrast, treatment with rapamycin, an mTOR inhibitor, produced the opposite phenotype. Taken together, these data suggested that the protective effects of Kae in BMSCs and in the OVX rat model resulted from the induction of osteogenesis via mTOR signaling, or at least partially via the regulation of downstream effectors of the mTOR pathway.

Autophagy in bone homeostasis and the onset of osteoporosis

Autophagy is an evolutionarily conserved intracellular process, in which domestic cellular components are selectively digested for the recycling of nutrients and energy. This process is indispensable for cell homeostasis maintenance and stress responses. Both genetic and functional studies have demonstrated that multiple proteins involved in autophagic activities are critical to the survival, differentiation, and functioning of bone cells, including osteoblasts, osteocytes, and osteoclasts. Dysregulation at the level of autophagic activity consequently disturbs the balance between bone formation and bone resorption and mediates the onset and progression of multiple bone diseases, including osteoporosis. This review aims to introduce the topic of autophagy, summarize the understanding of its relevance in bone physiology, and discuss its role in the onset of osteoporosis and therapeutic potential.

Osseointegration of osteoporotic bone implants: Role of stem cells, Silica and Strontium - A concise review

Osteoporotic fracture treatment has become a skeletal reconstructive challenge due to accelerated bone turnover and impaired bone regeneration potential. Poor osseointegration ability of the osteoporotic bone usually results in implant pull out and failure. Adoption of conventional bone fracture treatment strategies like autografts and allografts have limited applications in such pathological conditions. Hence biomaterials functionalised with therapeutic ions or drugs may be adopted to aid the delivery of therapeutic factors at the defect site to promote bone healing and implant integration, towards functional restoration of the fractured bone. This concise review narrates on improving the osseointegration ability of biomaterials using functional ions like Silica and Strontium. Silica based bone substitutes are known to promote bone healing in non pathological conditions. Further, Strontium based drugs show significant effects in the prevention and treatment of osteoporotic bones. In addition, stem cell therapy has become the focus of orthopaedic research attributed to its ability to restore and accelerate the bone healing process, but the clinical application of stem cells in osteoporotic condition is scarce. Present review suggests a novel strategy of combining the therapeutic potential of functional ions like Silica, Strontium and stem cells within a single implant unit to facilitate osseointegration and osteogenesis, so as to reduce the chances of implant rejection/pull out and encourage osteoporotic bone re-union.

Building for better bones: evaluation of a clinical pathway in the secondary prevention of osteoporotic fractures

Objective

Osteoporosis is a common disease that is underdiagnosed and undertreated. A multidisciplinary intervention may improve the identification and treatment of osteoporosis and may consequently prevent secondary fractures.

Method

Retrospective, single-centre study comparing attitude to screening and treatment of patients admitted to the orthopaedic unit of the general hospital AZ Sint-Jan Brugge-Oostende AV (Belgium) before and after the implementation of a clinical pathway.

Results

A total of 172 patients (86 before and 86 after) were included in this study. The implementation of the pathway resulted in an increase in bone mineral density tests performed, an increment in the number of referrals to a specialist in the field of osteoporosis, and an increase in prevention and treatment of osteoporosis.

Conclusion

The implementation of a clinical pathway coordinated and evaluated by a clinical pharmacist improved the identification, referral and treatment of osteoporosis in patients hospitalised due to low-impact fractures.

Stem cells in Osteoporosis: From Biology to New Therapeutic Approaches

Osteoporosis is a systemic disease that affects the skeleton, causing reduction of bone density and mass, resulting in destruction of bone microstructure and increased risk of bone fractures. Since osteoporosis is a disease affecting the elderly and the aging of the world's population is constantly increasing, it is expected that the incidence of osteoporosis and its financial burden on the insurance systems will increase continuously and there is a need for more understanding this condition in order to prevent and/or treat it. At present, available drug therapy for osteoporosis primarily targets the inhibition of bone resorption and agents that promote bone mineralization, designed to slow disease progression. Safe and predictable pharmaceutical means to increase bone formation have been elusive. Stem cell therapy of osteoporosis, as a therapeutic strategy, offers the promise of an increase in osteoblast differentiation and thus reversing the shift towards bone resorption in osteoporosis. This review is focused on the current views regarding the implication of the stem cells in the cellular and physiologic mechanisms of osteoporosis and discusses data obtained from stem cell-based therapies of osteoporosis in experimental animal models and the possibility of their future application in clinical trials.

Ligustilide, a major bioactive component of Angelica sinensis, promotes bone formation via the GPR30/EGFR pathway

Angelica sinensis (Oliv.) Diels is a widely-used traditional Chinese herbal medicine in treating osteoporosis. Ligustilide (LIG) is the main component of A. sinensis and is considered to be the most effective biologically active ingredient in this plant. LIG has been found to have multiple pharmacological activities, such as anti-atherosclerosis, neuroprotection, anticancer, anti-inflammatory and analgesic. However, little is known regarding its anti-osteoporotic effects. The aims of this study were to investigate any protective effect of LIG on bone formation. The results showed that LIG significantly ameliorated inhibition of bone formation in zebrafish caused by prednisolone. LIG promoted osteoblast differentiation, including that of the pre-osteoblastic cell line MC3T3-E1 and bone marrow mesenchymal stem cells. LIG greatly improved the viability of MC3T3-E1 cells exposed to H₂O₂, attenuated H₂O₂-induced apoptosis and increased the expression of Bcl-2. Furthermore, LIG treatment lead to marked activation of phosphorylated EGFR and ERK1/2. These effects could be obviously inhibited by blocking GPR30 signaling with the specific inhibitor G15. Collectively, the results reveal that GPR30 is a positive switch for LIG to increase bone formation via regulation of EGFR, and these results provide evidence for the potential of LIG to treat osteoporosis.

Arbutin promotes MC3T3‑E1 mouse osteoblast precursor cell proliferation and differentiation via the Wnt/β‑catenin signaling pathway

Arbutin is a natural compound extracted from various plants, including bearberry leaves, that exerts multiple effects including skin whitening, anti‑inflammatory and oxidative stress‑protective properties. However, the effects of arbutin on osteoblasts remain unknown. The aim of the present study was to investigate the function and the mechanisms of arbutin on the proliferation and differentiation of MC3T3‑E1 mouse osteoblast precursor cells in vitro. The proliferation of MC3T3‑E1 cells treated with arbutin was assessed using a Cell Counting Kit‑8 assay and a 5‑ethynyl‑2'‑deoxyuridine labeling assay. Additionally, cell cycle and apoptosis were examined using flow cytometry analysis. The effects of arbutin on osteoblast differentiation were investigated using alkaline phosphatase (ALP) staining and by examining the mRNA expression levels of collagen type I α1 chain (COL1A1), bone γ‑carboxyglutamate protein (BGLAP) and Sp7 transcription factor (SP7). To further investigate the molecular mechanism underlying arbutin function in promoting osteogenesis, the mRNA and protein expression levels of runt‑related transcription factor 2 (RUNX2) and β‑catenin were analyzed by reverse transcription‑quantitative polymerase chain reaction and western blotting. Arbutin significantly promoted MC3T3‑E1 cell proliferation and increased the ratio of cells in S‑phase. Treatment with arbutin increased ALP activity and the mRNA expression levels of COL1A1, BGLAP and SP7 in MC3T3‑E1 cells. Furthermore, the protein and the mRNA expression levels of RUNX2 and β‑catenin increased significantly following treatment with arbutin. Collectively, the present findings suggested that arbutin was able to promote proliferation and differentiation of MC3T3‑E1 cells via the Wnt/β‑catenin signaling pathway.

An Evaluation of the Association of Reproductive History and Multiple Births during Adolescence with Postmenopausal Osteoporosis

Introduction Osteoporosis is the most common metabolic bone disease characterized by low bone mass. Reproductive factors are known to affect bone mineral density (BMD). Calcium loss from maternal bone and decreased BMD have been observed especially during pregnancy and lactation, although this loss has been reported to recover within 6 – 12 months. There is no consensus on whether the effect of reproductive factors on the bone is positive or negative. The adolescent period is important for total bone mass, and total bone mass is significant in osteoporosis. The aim of this study was to investigate the effect of first gestational age, multiple births during adolescence, interpregnancy interval and reproductive history such as duration of breastfeeding on bone mineral density in postmenopausal women.

Materials and Methods BMD was measured in a total of 196 postmenopausal patients and in accordance with the results, analysis was made of three groups as normal, osteopenia and osteoporosis. Dual Energy X-Ray Absorptiometry (DEXA) was used to take the lumbar, femoral and total bone BMD measurements.

Results No statistically significant difference was determined between the groups in respect of total breastfeeding time (p = 0.596). It was detected that an increased interpregnancy interval decreased the risk of osteoporosis. In patients with osteoporosis, the mean interpregnancy interval was 1.4 ± 0.73 years, while it was longer in patients with osteopenia (1.92 ± 1.20) and normal BMD (2.45 ± 1.77) (p = 0.005). While no effect was determined of the first gestational age on BMD, in the univariate logistic regression analysis, multiple births in the adolescent period were seen to increase the risk of osteoporosis 6.833-fold (p = 0.001, OR = 6.833, 95% CI = 2.131 – 21.908; p = 0.001). The increase in the age of menopause was determined to decrease the risk of osteoporosis (OR = 0.911, 95% CI = 0.843 – 0.985; p = 0.019).

Conclusion Having frequent births throughout the whole reproductive age and having more than one child in adolescence has an adverse effect on postmenopausal bone mineral densities.

Retention of osteocytic micromorphology by sclerostin antibody in a concurrent ovariectomy and functional disuse model

Prolonged mechanical unloading in bedridden patients and concurrent hormonal dysregulation represents the cause of one of the severest forms of osteoporosis, a condition for which there are very few efficacious interventions available to date. Sclerostin, a Wnt antagonist, acts as a negative regulator of bone formation. Sclerostin antibody (Scl-Ab)-mediated blockade of sclerostin can dramatically enhance bone formation and reduce bone resorption. This study was designed to investigate the therapeutic effect of the Scl-Ab on severe bone loss induced by concurrent mechanical unloading and estrogen deficiency in a hindlimb-suspended and ovariectomized rat model, and to study the cellular mechanisms underlying severe osteoporosis and Scl-Ab action. Unloading and ovariectomy resulted in severe loss of trabecular and cortical bone mass and strength; Scl-Ab can significantly counteract the deterioration of bone in unloaded and/or ovariectomized rats, with noticeably increased cortical bone formation. Scanning electron microscopy analysis revealed that unloading and ovariectomy lead to multiple morphological and structural abnormalities of osteocytes in cortical bone and the abnormalities were abolished by Scl-Ab administration. This study extends our previous conclusion that Scl-Ab represents a promising therapeutic approach for severe bone loss that occurs after being exposed to estrogen deficiency and prolonged mechanical unloading.

Metabolomics-based profiles predictive of low bone mass in menopausal women

Osteoporosis is a skeletal disorder characterized by compromised bone strength and increased risk of fracture. Low bone mass and/or pre-existing bone fragility fractures serve as diagnostic criteria in deciding when to start medication for osteoporosis. Although osteoporosis is a metabolic disorder, metabolic markers to predict reduced bone mass are unknown. Here, we show serum metabolomics profiles of women grouped as pre-menopausal with normal bone mineral density (BMD) (normal estrogen and normal BMD; NN), post-menopausal with normal BMD (low estrogen and normal BMD; LN) or post-menopausal with low BMD (low estrogen and low BMD; LL) using comprehensive metabolomics analysis. To do so, we enrolled healthy volunteer and osteoporosis patient female subjects, surveyed them with a questionnaire, measured their BMD, and then undertook a comprehensive metabolomics analysis of sera of the three groups named above. We identified 24 metabolites whose levels differed significantly between NN/LN and NN/LL groups, as well as 18 or 10 metabolites whose levels differed significantly between NN/LN and LN/LL, or LN/LL and NN/LN groups, respectively. Our data shows metabolomics changes represent useful markers to predict estrogen deficiency and/or bone loss.

Osteogenic effects of Phlomis umbrosa via up-regulation of Runx2 in osteoporosis

Phlomis umbrosa Turcz (labiatae) has been suggested to promote bone growth. However, the anti-osteoporotic effects of P. umbrosa have not yet been elucidated. In the present study, the osteogenic effects of P. umbrosa were investigated in an osteoporosis model. ICR female mice were ovariectomized (OVX) to induce osteoporosis for 7 weeks. Treatment with 1, 10 and 100 mg/kg P. umbrosa was administrated orally to the OVX mice for 6 weeks. At the end of experiment, the microstructure of the capital femoral epiphysis was investigated. The levels of bone mineral density (BMD), bone mineral content (BMC) and serum osteocalcin concentration were evaluated. In addition, mineralized Saos-2 osteoblast cells were treated with 0.01, 0.1 and 1 µg/ml P. umbrosa to analyze the expression of osteoblast differentiation-associated factors. Hyperplasia of the growth plate in the femur was recovered by P. umbrosa treatment. BMD and BMC were significantly increased in P. umbrosa-treated femurs. Serum calcium concentration was increased following P. umbrosa treatment. In addition, the ratio of mineralization was markedly increased in P. umbrosa-treated differentiated osteoblasts along with increases in Runx2 levels. P. umbrosa conferred its osteogenic effects by upregulating Runx2 in osteoporosis. P. umbrosa may be a potential therapeutic material for the treatment of osteoporosis.

Geraniin promotes osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) via activating β-catenin: a comparative study between BMSCs from normal and osteoporotic rats

Abnormal osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) has been correlated with the pathogenesis of osteoporosis. Geraniin, a polyphenolic compound isolated from Phyllanthus amarus, is effective in preventing osteoporosis, but the mechanisms of action of geraniin and the impact of osteoporotic condition on drug action are not known. In this study we compared the proliferation and osteoblastic differentiation potential of BMSCs from normal rats with that from osteoporotic rats, and examined the responses of both BMSCs to geraniin in parallel. BMSCs of rats subjected to ovariectomy or sham operation were isolated and treated with geraniin. Cell proliferation was measured by CCK-8 assay. Osteoblastic differentiation was quantified by Alizarin Red S staining and alkaline phosphatase assay. Nuclear translocation of β-catenin was monitored by immunofluorescent staining. Expression of β-catenin was determined by Western blot and quantitative real-time polymerase chain reaction. Results showed that the proliferation and osteoblast formation of osteoporotic BMSCs decreased in comparison to that of normal BMSCs. Geraniin enhanced proliferation and osteoblastic differentiation of both BMSCs, but the responses of osteoporotic BMSCs to geraniin were less than those of normal BMSCs. Expression and nuclear accumulation of β-catenin in osteoporotic BMSCs were found to be diminished. Geraniin increased nuclear translocation and expression of β-catenin in both BMSCs. This study associated the osteogenic effect of geraniin to activation of Wnt/β-catenin signaling, and provided rationale for pharmacological investigation of geraniin in osteoporosis prevention and treatment.

Design of a transdermal formulation containing raloxifene nanoparticles for osteoporosis treatment

Purpose

In the clinical setting, raloxifene, a second-generation selective estrogen receptor modulator, is administered orally; however, the bioavailability (BA) is only 2% because of its poor solubility in aqueous fluids and its extensive first-pass metabolism. Therefore, it is expected that the development of a transdermally delivered formulation may reduce the necessary dose without compromising its therapeutic efficacy. In this study, we designed transdermal formulations containing raloxifene nanoparticles and evaluated their usefulness for osteoporosis therapy.

Methods

Raloxifene was crushed with methylcellulose by the bead mill method, and the milled raloxifene was gelled with or without menthol (a permeation enhancer) by Carbopol^® 934 (without menthol, Ral-NPs; with menthol, mRal-NPs). 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.

Results

The mean particle size of raloxifene in the transdermal formulation (Ral-NPs) was 173.7 nm. 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. On the other hand, inclusion of menthol in the formulation attenuated the barrier function of the stratum corneum and permitted the penetration of raloxifene nanoparticles through the skin. Moreover, macropinocytosis relates to the skin penetration of the formulation including menthol (mRal-NPs), since penetration was inhibited by treatment with 2 µM rottlerin, a macropinocytosis inhibitor. In addition, the application of 0.3% mRal-NPs (once a day) attenuated the decreases in calcium level and stiffness of the bones of ovariectomized rat.

Conclusion

We prepared raloxifene solid nanoparticles by a bead mill method and designed a novel transdermal formulation containing nanoparticles and permeation enhancers. These trans-dermal formulations overcome the barrier properties of the skin and show high drug penetration through the transdermal route (BA 8.5%). In addition, we found that raloxifene transdermal formulations are useful for the treatment of osteoporosis in ovariectomized rat.

Bone regeneration with umbilical cord blood mesenchymal stem cells in femoral defects of ovariectomized rats

OBJECTIVES

Current treatments for osteoporosis were prevention of progression, yet it has been questionable in the stimulation of bone growth. The mesenchymal stem cells (MSCs) treatment for osteoporosis aims to induce differentiation of bone progenitor cells into bone-forming osteoblasts. We investigate whether human umbilical cord blood (hUCB)-MSCs transplantation may induce bone regeneration for osteoporotic rat model induced by ovariectomy.

METHODS

The ovariectomized (OVX) group (n = 10) and OVX-MSCs group (n = 10) underwent bilateral ovariectomy to induce osteoporosis, while the Sham group (n = 10) underwent sham operation at aged 12 weeks. After a femoral defect was made at 9 months, Sham group and OVX group were injected with Hartmann solution, while the OVX-MSCs group was injected with Hartmann solution containing 1 × 107 hUCB-MSCs. The volume of regenerated bone was evaluated using micro-computed tomography at 4 and 8 weeks postoperation.

RESULTS

At 4- and 8-week postoperation, the OVX group (5.0% ± 1.5%; 6.1% ± 0.7%) had a significantly lower regenerated bone volume than the Sham group (8.6% ± 1.3%; 12.0% ± 1.8%, P < 0.01), respectively. However, there was no significant difference between the OVX-MSCs and Sham groups. The OVX-MSCs group resulted in about 53% and 65% significantly higher new bone formation than the OVX group (7.7% ± 1.9%; 10.0% ± 2.9%, P < 0.05).

CONCLUSIONS

hUCB-MSCs in bone defects may enhance bone regeneration in osteoporotic rat model similar to nonosteoporotic bone regeneration. hUCB-MSCs may be a promising alternative stem cell therapy for osteoporosis.

Pine needles attenuate receptor activator for nuclear factor-B ligand (RANKL)-induced trabecular bone loss by inhibiting osteoclast differentiation

Background

The leaf of Pinus densiflora known as pine needles has been used to treat vascular disease, gastrointestinal diseases, and urinary diseases in traditional medicine. We evaluated anti-osteoporotic effect of water extract of Pinus densiflora (WEPN) on acute bone loss and osteoclastogenesis induced by receptor activator for nuclear factor-κB ligand (RANKL).

Methods

After oral administration of WEPN (0.25 g/kg) for 5 days, femora were collected, and bone parameter [trabecular bone volume/tissue volume (BV/TV), trabecular thickness (Tb. Th), trabecular separation (Tb. Sp), trabecular number (Tb. N), and bone mineral density (BMD)] were analyzed by micro-CT analysis. Anti-osteoclastic effect of WEPN was examined using tartrate-resistant acid phosphatase activity and activation of RANKL signaling pathway.

Results

We found that WEPN significantly attenuated RANKL-induced decrease of BV/TV, Tb.Th., Tb.N, and BMD but increase of Tb. Sp in femora. WEPN dose-dependently decreased osteoclastogenesis accompanied by inhibiting the activation of RANKL signaling components (JNK, p38, and p65) and mRNA expression level of osteoclast specific genes (NFATc1, c-Fos, TRAP, cathepsin K, DC-STAMP, and carbonic anhydrate).

Conclusion

WEPN inhibition on osteoclastogenesis could contribute to attenuate RANKL-induced trabecular bone loss in vivo. Therefore, it might suggest that WEPN could be prescribed in traditional medicine or used in health functional food to prevent or treat osteoporotic bone diseases.

Osteoporosis: A Review of Treatment Options

Approximately 10 million men and women in the U.S. have osteoporosis,1 a metabolic bone disease characterized by low bone density and deterioration of bone architecture that increase the risk of fractures.2 Osteoporosis-related fractures can increase pain, disability, nursing home placement, total health care costs, and mortality.3 The diagnosis of osteoporosis is primarily determined by measuring bone mineral density (BMD) using noninvasive dual-energy x-ray absorptiometry. Osteoporosis medications include bisphosphonates, receptor activator of nuclear factor kappa-B ligand inhibitors, estrogen agonists/antagonists, parathyroid hormone analogues, and calcitonin.3-6 Emerging therapies utilizing novel mechanisms include a cathepsin K inhibitor and a monoclonal antibody against sclerostin.7,8 While professional organizations have compiled recommendations for the management of osteoporosis in various populations, a consensus has yet to develop as to which is the gold standard; therefore, economic evaluations have been increasingly important to help guide decision-makers. A review of cost-effectiveness literature on the efficacy of oral bisphosphonates has shown alendronate and risedronate to be most cost-effective in women with low BMD without previous fractures.9 Guidelines are inconsistent as to the place in therapy of denosumab (Prolia, Amgen). In economic analyses evaluating treatment of postmenopausal women, denosumab outperformed risedronate and ibandronate; its efficacy was comparable to generic alendronate, but it cost more.10 With regard to older men with osteoporosis, denosumab was also found to be cost-effective when compared with bisphosphonates and teriparatide (Forteo, Lilly).11.

Low-energy extracorporeal shockwave therapy (ESWT) improves metaphyseal fracture healing in an osteoporotic rat model

Purpose

As result of the current demographic changes, osteoporosis and osteoporotic fractures are becoming an increasing social and economic burden. In this experimental study, extracorporeal shock wave therapy (ESWT), was evaluated as a treatment option for the improvement of osteoporotic fracture healing.

Methods

A well-established fracture model in the metaphyseal tibia in the osteoporotic rat was used. 132 animals were divided into 11 groups, with 12 animals each, consisting of one sham-operated group and 10 ovariectomized (osteoporotic) groups, of which 9 received ESWT treatment. Different energy flux intensities (0.15 mJ/mm², 0.35 mJ/mm², or 0.55 mJ/mm²) as well as different numbers of ESWT applications (once, three times, or five times throughout the 35-day healing period) were applied to the osteoporotic fractures. Fracture healing was investigated quantitatively and qualitatively using micro-CT imaging, quantitative real-time polymerase chain reaction (qRT-PCR) analysis, histomorphometric analysis and biomechanical analysis.

Results

The results of this study show a qualitative and quantitative improvement in the osteoporotic fracture healing under low-energy (energy flux intensity: 0,15 mJ/mm²) ESWT and with fewer treatment applications per healing period.

Conclusion

In conclusion, low-energy ESWT seems to exhibit a beneficial effect on the healing of osteoporotic fractures, leading to improved biomechanical properties, enhanced callus-quantity and -quality, and an increase in the expression of bone specific transcription factors. The results suggest that low-energy ESWT, as main treatment or as adjunctive treatment in addition to a surgical intervention, may prove to be an effective, simple to use, and cost-efficient option for the qualitative and quantitative improvement of osteoporotic fracture healing.

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.

Pharmacological Therapy of Osteoporosis: A Systematic Current Review of Literature

Osteoporosis is the most common bone disease affecting millions of people worldwide, particularly in elderly or in post-menopausal women. The pathogenesis is useful to understand the possible mechanism of action of anti-osteoporotic drugs. Early diagnosis, possible with several laboratory and instrumental tests, allows a major accuracy in the choice of anti-osteoporosis drugs. Treatment of osteoporosis is strictly related to severity of pathology and consists on prevention of fragility fractures with a correct lifestyle and adequate nutritional supplements, and use of pharmacological therapy, started in patients with osteopenia and history of fragility fracture of the hip or spine. The purpose of this review is to focus on main current pharmacological products to treat osteoporotic patients.

Evidence based anti-osteoporosis effects of Periplaneta americana L on osteoblasts, osteoclasts, vascular endothelial cells and bone marrow derived mesenchymal stem cells

Background

Kangfuxin (KFX) is the ethanol extract of Periplaneta americana L, which has been widely used in the Traditional Chinese Medicine for the repair and regeneration of injured organ and tissues with long history. This study is to investigate the influence of KFX in the various cellular activities and evaluate the anti-osteoporosis potential of KFX.

Methods

The influence of the KFX in the cellular activities, including: 1) migration, osteocalcin secretion of osteoblasts; 2) apoptosis of osteoclasts; 3) migration and tube formation of human umbilical vein endothelial cell (HUVEC); and 4) proliferation, cell cycle regulation and migration of bone marrow mesenchymal stem cells (BMSCs), were investigated systematically.

Results

KFX was shown to significantly 1) Promote of the migration of osteoblasts, HUVEC, and BMSCs; 2) Increase the secretion of osteocalcin and mineralization of osteoblasts; 3) Accelerate the apoptosis of osteoclasts; 4) Stimulate the proliferation and regulate the cell cycle of BMSCs.

Conclusion

Taken together, these results provide the evidence for the osteogenesis, anti-osteoporosis and angiogenesis effects of KFX, with the mechanism of activating the bone formation through stimulating the osteoblasts and HUVECs, as well as inhibiting the bone absorption by inhibiting the osteoclasts activities. The KFX was definitely shown a promising bone turnover agent with great potential for anti-osteoporosis treatment.