Predicting the intervention threshold for initiating osteoporosis treatment among postmenopausal women in China: a cost-effectiveness analysis based on real-world data

Insights and implications of sexual dimorphism in osteoporosis

Osteoporosis, a metabolic bone disease characterized by low bone mineral density and deterioration of bone microarchitecture, has led to a high risk of fatal osteoporotic fractures worldwide. Accumulating evidence has revealed that sexual dimorphism is a notable feature of osteoporosis, with sex-specific differences in epidemiology and pathogenesis. Specifically, females are more susceptible than males to osteoporosis, while males are more prone to disability or death from the disease. To date, sex chromosome abnormalities and steroid hormones have been proven to contribute greatly to sexual dimorphism in osteoporosis by regulating the functions of bone cells. Understanding the sex-specific differences in osteoporosis and its related complications is essential for improving treatment strategies tailored to women and men. This literature review focuses on the mechanisms underlying sexual dimorphism in osteoporosis, mainly in a population of aging patients, chronic glucocorticoid administration, and diabetes. Moreover, we highlight the implications of sexual dimorphism for developing therapeutics and preventive strategies and screening approaches tailored to women and men. Additionally, the challenges in translating bench research to bedside treatments and future directions to overcome these obstacles will be discussed.

Fracture risk prediction in old Chinese people-a narrative review

With aging, the burden of osteoporotic fracture (OF) increases substantially, while China is expected to carry the greatest part in the future. The risk of fracture varies greatly across racial groups and geographic regions, and systematically organized evidence on the potential predictors for fracture risk is needed for Chinese. This review briefly introduces the epidemiology of OF and expands on the predictors and predictive tools for the risk of OF, as well as the challenges for their potential translation in the old Chinese population. There are regional differences of fracture incidence among China. The fracture incidences in Hong Kong and Taiwan have decreased in recent years, while it is still increasing in mainland China. Although the application of dual-energy X-ray absorptiometry (DXA) is limited among old Chinese in the mainland, bone mineral density (BMD) by DXA has a predictive value similar to that worldwide. Other non-DXA modalities, especially heel QUS, are helpful in assessing bone health. The fracture risk assessment tool (FRAX) has a good discrimination ability for OFs, especially the FRAX with BMD. And some clinical factors have added value to FRAX, which has been verified in old Chinese. In addition, although the application of the osteoporosis self-assessment tool for Asians (OSTA) in Chinese needs further validation, it may help identify high-risk populations in areas with limited resources. Moreover, the translation use of the muscle quality and genetic or serum biomarkers in fracture prediction needs further works. More applicable and targeted fracture risk predictors and tools are still needed for the old Chinese population.

Assessment for bone health in patients with differentiated thyroid carcinoma after postoperative thyroid-stimulating hormone suppression therapy: a new fracture risk assessment algorithm

Purpose

The fracture risk assessment tool (FRAX) is used to assess the 10-year risk of major site and hip fractures; however, whether this tool can be applied to patients receiving levothyroxine-based thyroid-stimulating hormone (TSH) suppressive therapy for postoperative differentiated thyroid cancer (DTC) patients is yet to be clarified.

Methods and design

A total of 64 patients with DTC following thyroidectomy and oral levothyroxine for TSH suppression therapy and 30 gender- and age-matched controls were collected. The fracture risk was compared between the affected groups with different TSH levels. FRAX was used to calculate the fracture risk with and without bone mineral density (BMD). The TSH level was converted to an age-weighted score to estimate the fracture risk of postoperatively differentiated thyroid cancer patients. The sensitivity, specificity, and area under the AUC curve of the traditional FRAX and the new algorithm for osteoporosis diagnosis were compared. The dual-energy X-ray bone mineral density measurement T score was used as the gold standard to diagnose osteoporosis.

Results

There were 24 patients in the T ≥ -1-2.5 group, 23 in the -2.5 < T < -1 group, and 17 in the T ≤ -2.5 group. The T score of BMD in the disease group was significantly lower than that in the control group (p < 0.05). The risk of MOF and hip fracture without a T score were significantly different under various TSH levels (p < 0.05). The area under the curve (AUC) of FRAX without BMD for predicting major osteoporotic fractures (PMOF) and major hip fractures (PHF) was 0.694 and 0.683, respectively. The cutoff values were 2.15% and 0.25%, respectively. The AUC of FRAX with BMD for PMOF and PHF was 0.976 and 0.989, respectively, and the cutoff values were 4.15% and 1.1%, respectively. The AUC of FRAX without BMD for PMOF and PHF was 0.708 and 0.72, respectively, and the cutoff values were 5.5% and 1.55%, respectively.

Conclusions

FRAX is suitable for postoperative DTC patients after TSH suppressive therapy. In the absence of BMD, TSH weighted by age can improve the specificity of FRAX in the diagnosis of osteoporosis in this population.

Impact of leptin or melatonin on Sema4D overexpression-related bone metabolism

PURPOSE

The current study aims to investigate the regulatory impact of leptin or melatonin on bone metabolism as well as the underlying mechanism in conjunction with Sema4D (monoclonal antibody to semaphorin 4D).

METHODS

Rats were used to create the osteoporosis model utilizing the OVX (OVariectomize) technique. Rat tibial specimens from each side were collected for three-dimensional reconstruction and Micro-CT scanning examination. The Hematoxylin-osinstaining (HE) staining technique was used to determine the pathological condition of bone tissues. The ELISA (Enzyme-Linked Immunosorbent Assay) assay was used to measure the amount of estradiol present in the serum. In the current study, there were six groups: control, OVX, OVX + NL (no load group), OVX + Sema4D, OVX + Sema4D + leptin, and OVX + Sema4D + MT (melatonin). Rats were given injections of the Sema4D or leptin overexpressing vectors via the tail vein in accordance with the aforementioned classification. By using a high-resolution micro-CT technology, 3D bone structure was discovered. The activity of tartrate-resistant acid phosphatase-5b (TRAP-5b) and bone-derived alkaline phosphatase (BALP) in serum was assessed using an ELISA. The number of osteoclasts in the metaphysis of the upper tibia was determined using TRAP (tartrate-resistant acid phosphatase) staining. Immunohistochemistry was used to find leptin and bone morphogenetic protein-2 (BMP-2) expressions in bone tissue.

RESULTS

The BV/TV (Bone volume/Tissue volume), Tb.N (Trabecular number), BMD (Bone Mineral Density), and BMC (Bone Mineral Content) levels were significantly higher in the OVX + Sema4D + leptin and OVX + Sema4D + MT groups compared to OVX + NL, while Tb.Sp (Trabecular separation) levels were significantly lower. In contrast to the OVX group, the bone trabeculae in the OVX + Sema4D + leptin and OVX + Sema4D + MT groups had a relatively complete structure and tended to be organized closely. The amount of bone trabeculae grew drastically, whereas the proportion of TRAP-positive osteoclasts declined dramatically. BMP-2 and leptin were also elevated, while BALP and TRAP-5b activity was reduced.

CONCLUSION

Leptin or melatonin improved Sema4d's role in trabecular bone microstructure, bone production, and repairment of trabecular bone loss in osteoporosis rats.

Safety Evaluation of Natural Drugs in Chronic Skeletal Disorders: A Literature Review of Clinical Trials in the Past 20 years

Chronic skeletal disorders (CSDs), including degenerative diseases such as osteoporosis (OP) and autoimmune disorders, have become a leading cause of disability in an ageing society, with natural drugs being indispensable therapeutic options. The clinical safety evaluation (CSE) of natural drugs in CSDs has been given priority and has been intensively studied. To provide fundamental evidence for the clinical application of natural drugs in the elderly population, clinical studies of natural drugs in CSDs included in this review were selected from CNKI, Web of Science, PubMed, Science Direct and Google Scholar since 2001. Seventeen randomized controlled trials (RCTs) met our inclusion criteria: four articles were on OP, seven on osteoarthritis (OA), four on rheumatoid arthritis (RA) and two on gout. Common natural drugs used for the treatment of OP include Epimedium brevicornu Maxim [Berberidaceae], Dipsacus asper Wall ex DC [Caprifoliaceae] root, and Phalaenopsis cornu-cervi (Breda) Blume & Rchb. f[ Orchidaceae], which have been linked to several mild adverse reactions, such as skin rash, gastric dysfunction, abnormal urine, constipation and irritability. The safety of Hedera helix L [Araliaceae] extract, Boswellia serrata Roxb [Burseraceae] extract and extract from perna canaliculus was evaluated in OA and upper abdominal pain, and unstable movements were obsrerved as major side effects. Adverse events, including pneumonia, vomiting, diarrhoea and upper respiratory tract infection, were reported when RA was treated with Tripterygium wilfordii, Hook. F [Celastraceae][TwHF] polyglycosides and quercetin (Capsella bursa-pastoris (L.) Medik [Brassicaceae]). The present review aimed to summarize the CSE results of natural drugs in CSDs and could provide evidence-based information for clinicians.

Exploring the Effect of Jiawei Buguzhi Pills on TGF-β-Smad Pathway in Postmenopausal Osteoporosis Based on Integrated Pharmacological Strategy

Objective

To explore the effect of Jiawei Buguzhi Pills (JWBGZP) on the TGF-β-Smad pathway in postmenopausal osteoporosis (PMO) based on integrated pharmacological strategy.

Method

The ETCM database was used to collect JWBGZP. GeneCards and OMIM databases were utilized to obtain PMO-related genes. Cytoscape was used for network construction and analysis, and DAVID was used for GO and KEGG enrichment analysis of key targets. Animal experiments and cell experiments were conducted to further explore the mechanism. The bone mass density was detected by dual-energy X-ray bone densitometer. The TGF-β1 and Smad4 mRNA in bone tissue were detected by RT-qPCR. The TGF-β1 and Smad4 protein in bone tissue were detected by the western blot. The TGF-β1 and Smad4 protein in osteoblasts were determined by immunohistochemistry.

Result

A total of 721 JWBGZP potential targets and 385 PMO-related genes were obtained. The enrichment analysis showed that JWBGZP may regulate the TGF-beta signaling pathway, oxidation-reduction process, aging, response to hypoxia, response to ethanol, negative regulation of cell proliferation, PI3K-Akt, HIF-1, and other signaling pathways. The animal experiments showed that compared with the model group, the femoral bone mineral density and lumbar bone mineral density of the JWBGZP group increased (P < 0.05); the expression levels of TGF-β1 and Smad mRNA and proteins in the JWBGZP group were significantly higher (P < 0.05). The cell experiment results showed a large number of osteoblast stained blue-purple and orange-red calcified nodules. The expression levels of TGF-β1 and Smad proteins in the JWBGZP group were significantly higher than those in the blank control group and the sham operation group, and the protein expression levels in the model group were the lowest (P < 0.05).

Conclusion

JWBGZP may be involved in PI3K-Akt, HIF-1, estrogen, prolactin, and other signaling pathways and regulate MAPK1, AKT1, PIK3CA, JAK2, and other gene targets, regulate bone metabolism, and thereby treat PMO.

Big Data and Real-World Data based Cost-Effectiveness Studies and Decision-making Models: A Systematic Review and Analysis

Background: Big data and real-world data (RWD) have been increasingly used to measure the effectiveness and costs in cost-effectiveness analysis (CEA). However, the characteristics and methodologies of CEA based on big data and RWD remain unknown. The objectives of this study were to review the characteristics and methodologies of the CEA studies based on big data and RWD and to compare the characteristics and methodologies between the CEA studies with or without decision-analytic models. Methods: The literature search was conducted in Medline (Pubmed), Embase, Web of Science, and Cochrane Library (as of June 2020). Full CEA studies with an incremental analysis that used big data and RWD for both effectiveness and costs written in English were included. There were no restrictions regarding publication date. Results: 70 studies on CEA using RWD (37 with decision-analytic models and 33 without) were included. The majority of the studies were published between 2011 and 2020, and the number of CEA based on RWD has been increasing over the years. Few CEA studies used big data. Pharmacological interventions were the most frequently studied intervention, and they were more frequently evaluated by the studies without decision-analytic models, while those with the model focused on treatment regimen. Compared to CEA studies using decision-analytic models, both effectiveness and costs of those using the model were more likely to be obtained from literature review. All the studies using decision-analytic models included sensitivity analyses, while four studies no using the model neither used sensitivity analysis nor controlled for confounders. Conclusion: The review shows that RWD has been increasingly applied in conducting the cost-effectiveness analysis. However, few CEA studies are based on big data. In future CEA studies using big data and RWD, it is encouraged to control confounders and to discount in long-term research when decision-analytic models are not used.

Intervention thresholds to identify postmenopausal women with high fracture risk: A single center study based on the Philippines FRAX model

Objectives

This study is designed to estimate appropriate intervention thresholds for the Philippines Fracture Risk Assessment Tool (FRAX) model to identify postmenopausal women with high fracture risk.

Methods

Age dependent intervention thresholds were calculated for a woman of body mass index 25 kg/m² aged 50-80 years with a previous fragility fracture without other clinical risk factors. Fixed thresholds were developed using a database of 1546 postmenopausal women who underwent dual-energy X-ray absorptiometry for clinical reasons. Major and hip fracture risks were estimated using clinical risk factors with and without bone mineral density (BMD) input. Women were categorized to high risk and low risk groups according to the age dependent thresholds. The best cut-points were determined considering the optimum sensitivity and specificity using receiver operating characteristic analysis.

Results

The age dependent intervention thresholds of major fracture risk ranged from 2.8 to 6.9% while hip fracture risk ranged from 0.4 to 3.0% between 50 and 80 years of age. Major fracture threshold of 3.75% and hip fracture threshold of 1.25% were the best fixed thresholds observed and non-inclusion BMD in the fracture risk estimations did not change the values. As a hybrid method, 3% major fracture and 1% hip fracture risks for those < 70 years old and age-dependent thresholds for those aged 70 years and above can be recommended.

Conclusions

The intervention thresholds estimated in the current study can be applied to identify Filipino postmenopausal women with a high fracture risk. Clinicians should decide on the type of thresholds most appropriate.

Estimating the future clinical and economic benefits of improving osteoporosis diagnosis and treatment among women in China: a simulation projection model from 2020 to 2040

Annual osteoporotic fractures is projected to increase by 135% from 6.9 M (2020) to 16.2 M (2040), increasing the economic burden by 121% from $29.9B (2020) to $65.9B (2040).

INTRODUCTION

Globally, aging populations drive significant increases in osteoporosis prevalence. In China, the number of women aged ≥ 65 years is expected to more than double from 2020 (91.5 M) to 2040 (183.6 M). Using a microsimulation model, impact of increased diagnosis and treatment of postmenopausal women (PMW) with osteoporosis on anticipated reduction in fractures and associated costs in China from 2020 to 2040 was projected.

METHODS

A microsimulation model was developed to project annual incidence and costs of osteoporotic fractures among PMW in China from 2020 to 2040. Fracture risk was estimated using the simplified Fracture Risk Assessment Tool (FRAX). Fractures estimates were based on annualized FRAX risk and impact of treatment. Published literature informed inputs for direct and indirect fracture costs, DXA screening costs, and treatment costs and efficacy. China's current screening and treatment rates were compared against 50% increases to (i) case finding (screening rate and subsequent treatment rate) and (ii) treatment rate among those at highest fracture risk.

RESULTS

From 2020 to 2040, 241.7 M osteoporotic fractures are projected to cost $997B. Increased treatment scenario prevented 24.6 M fractures and saved $56B. Increased case finding scenario prevented 26 M fractures and saved $61.7B.

CONCLUSION

Osteoporosis underdiagnosis and undertreatment among the aging Chinese population will considerably burden patients, caregivers, and society. Policy changes to increase screening and treatment rates may result in significant cost savings and clinical benefits.

Development of the Asia Pacific Consortium on Osteoporosis (APCO) Framework: clinical standards of care for the screening, diagnosis, and management of osteoporosis in the Asia-Pacific region

Guidelines for doctors managing osteoporosis in the Asia-Pacific region vary widely. We compared 18 guidelines for similarities and differences in five key areas. We then used a structured consensus process to develop clinical standards of care for the diagnosis and management of osteoporosis and for improving the quality of care.

PURPOSE

Minimum clinical standards for assessment and management of osteoporosis are needed in the Asia-Pacific (AP) region to inform clinical practice guidelines (CPGs) and to improve osteoporosis care. We present the framework of these clinical standards and describe its development.

METHODS

We conducted a structured comparative analysis of existing CPGs in the AP region using a "5IQ" model (identification, investigation, information, intervention, integration, and quality). One-hundred data elements were extracted from each guideline. We then employed a four-round Delphi consensus process to structure the framework, identify key components of guidance, and develop clinical care standards.

RESULTS

Eighteen guidelines were included. The 5IQ analysis demonstrated marked heterogeneity, notably in guidance on risk factors, the use of biochemical markers, self-care information for patients, indications for osteoporosis treatment, use of fracture risk assessment tools, and protocols for monitoring treatment. There was minimal guidance on long-term management plans or on strategies and systems for clinical quality improvement. Twenty-nine APCO members participated in the Delphi process, resulting in consensus on 16 clinical standards, with levels of attainment defined for those on identification and investigation of fragility fractures, vertebral fracture assessment, and inclusion of quality metrics in guidelines.

CONCLUSION

The 5IQ analysis confirmed previous anecdotal observations of marked heterogeneity of osteoporosis clinical guidelines in the AP region. The Framework provides practical, clear, and feasible recommendations for osteoporosis care and can be adapted for use in other such vastly diverse regions. Implementation of the standards is expected to significantly lessen the global burden of osteoporosis.

Sex-specific associations of serum insulin-like growth factor-1 with bone density and risk of fractures in Chinese patients with type 2 diabetes

We evaluated the associations of serum insulin-like growth factor-1 (IGF-1) with bone mineral density (BMD) and risk of fractures in Chinese patients with type 2 diabetes (T2D). We found positive associations between IGF-I and BMD and negative associations between IGF-I and all three modified 10-year probabilities of MOFs and HFs in men, but not in women.

INTRODUCTION

The objective was to investigate the associations of serum insulin-like growth factor-1 (IGF-1) with bone mineral density (BMD) and risk of fractures in Chinese patients with type 2 diabetes (T2D) in each gender.

METHODS

This was a cross-sectional, retrospective study that included men over 50 years and postmenopausal women with T2D without medical conditions or medications known to significantly affect BMD or serum IGF-I levels. Data of IGF-1, bone metabolism markers, lumbar spine (LS), femoral neck (FN), and total hip (TH) BMD were obtained; 10-year probability of major osteoporotic fractures (MOFs) and hip fractures (HFs) was calculated and modified with rheumatoid arthritis, femoral neck T-score, and age. Correlations of IGF-1 levels with bone metabolism and risk of fractures were statistically analyzed in men and women, respectively.

RESULTS

A total of 391 patients, including 226 men and 165 women, were included. The age, serum fasting C-peptide, glycosylated hemoglobin (HbA1c), bone formation marker, and all three modified 10-year probabilities of MOFs and HFs were higher in women than those in men (all p < 0.05). The levels of 25 hydroxyvitamin D (25OHD), IGF-1, and BMD were lower in women than those in men (all p < 0.05). In men, IGF-1 was positively correlated with FN and TH BMD (FN BMD: r = 0.267, p < 0.001; TH BMD: r = 0.235, p < 0.001) and negatively correlated with all three modified 10-year probabilities of MOFs (RA-modified MOFs: r = - 0.289, p < 0.001; age-modified MOFs: r = - 0.237, p < 0.001; FN T-score-modified MOFs: r = - 0.280, p < 0.001) and HFs (RA-modified HFs: r = - 0.291, p < 0.001; age-modified HFs: r = - 0.271, p < 0.001; FN T-score-modified HFs: r = - 0.270, p < 0.001), while no significant correlations were found between serum IGF-I and BMD and three modified 10-year probability in women.

CONCLUSIONS

According to this study, we found sex differences in the associations of serum IGF-1 with BMD and risk of fractures in Chinese patients with T2D. These results suggested that increasing serum IGF-1 might be a clinical target for protecting fractures in T2D, especially in men.

Coenzyme Q10 inhibits RANKL-induced osteoclastogenesis by regulation of mitochondrial apoptosis and oxidative stress in RAW264.7 cells

Coenzyme Q10 (CoQ10) has been reported to improve bone density and the number of trabeculae in postmenopausal osteoporosis, but the mechanism remains to be elucidated. We aimed to investigate the effects of CoQ10 on receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis and the underlying molecular mechanisms. RAW264.7 cells were treated with different concentrations of RANKL to differentiate into osteoclasts, and then these cells were treated with different concentrations of CoQ10 with or without H₂ O₂ . Tartrate-resistant acid phosphatase staining was performed to detect osteoclasts. Cell viability was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, cell apoptosis was examined by flow cytometry, and the effects of CoQ10 on protein and messenger RNA expression of mitochondrial apoptosis-associated proteins and osteoclast marker proteins were measured by quantitative reverse transcription polymerase chain reaction and western blot, respectively. Furthermore, enzyme-linked immunosorbent assay was conducted to analyze the activities of malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT). RANKL significantly induced osteoclastogenesis in RAW264.7 cells, with the greatest efficiency at 50 ng/ml. CoQ10 had no significant effects on cell viability but it significantly increased the percentages of cell apoptosis. Mechanically, CoQ10 statistically decreased the levels of Bcl-2 and cytochrome C in mitochondria and upregulated the levels of Bax, cleaved caspase 3, and cytochrome C in the cytoplasm. Moreover, CoQ10 significantly decreased RANKL-induced osteoclastogenesis regardless of exposure to H₂ O₂ . In addition, CoQ10 statistically reduced MDA activity and elevated the activities of SOD and CAT, as well as the expression of oxidative stress-related proteins. CoQ10 may inhibit RANKL-induced osteoclastogenesis by regulation of mitochondrial apoptosis and oxidative stress in RAW264.7 cells.

An Updated Systematic Review of Cost-Effectiveness Analyses of Drugs for Osteoporosis

BACKGROUND

Considering the heavy economic burden of osteoporotic fractures, the limits of healthcare resources, and the recent availability of new anti-osteoporosis drugs, there is continuing interest in economic evaluation studies of osteoporosis management strategies.

OBJECTIVES

This study aims to (1) systematically review recent economic evaluations of drugs for osteoporosis and (2) to apply an osteoporosis-specific guideline to critically appraise them.

METHODS

A literature search was undertaken using PubMed, EMBASE, National Health Service Economic Evaluation database, and the Cost-Effectiveness Analysis Registry to identify original articles containing economic evaluations of anti-osteoporosis drugs, published between 1 July, 2013 and 31 December, 2019. A recent European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases-International Osteoporosis Foundation (ESCEO-IOF) guideline for the conduct and reporting of economic evaluations in osteoporosis was used to assess the quality of included articles.

RESULTS

The database search retrieved 3860 records, of which 27 studies fulfilled the inclusion criteria. These studies were conducted in 15 countries; 12 active drugs were assessed, including various traditional pharmacological treatments such as bisphosphonates, raloxifene, strontium ranelate, denosumab, and teriparatide, and new agents such as abaloparatide, romosozumab, and gastro-resistant risedronate. Eight out of 12 studies that compared traditional oral bisphosphonates to other active interventions (denosumab, zoledronic acid, gastro-resistant risedronate, and teriparatide) suggested that the other active agents were generally cost-effective or dominant. Additionally, the cost-effectiveness of sequential therapy has recently been assessed and indications are that it can lead to extra health benefits (larger gains in quality-adjusted life-year). The key drivers of cost effectiveness included baseline fracture risk, drug effect on the risk of fractures, drug cost, and medication adherence/persistence. The current average score for quality assessment was 17 out of 25 (range 2-15); room for improvement was observed for most studies, which could potentially be explained by the fact that most studies were published prior to the osteoporosis-specific guideline. Greater adherence to guideline recommendations was expected for future studies. The quality of reporting was also suboptimal, especially with regard to treatment side effects, treatment effect after discontinuation, and medication adherence.

CONCLUSIONS

This updated review provides an overview of recently published cost-effectiveness analyses. In comparison with a previous review, recent economic evaluations of anti-osteoporosis drugs were conducted in more countries and included more active drugs and sequential therapy as interventions/comparators. The updated economic evidence could help decision makers prioritize health interventions and the unmet/unreported quality issues indicated by the osteoporosis-specific guideline could be useful in improving the transparency, quality, and comparability of future economic evaluations in osteoporosis.

Cnidium lactone prevents bone loss in an ovariectomized rat model through the estrogen-α/BMP-2/Smad signaling pathway

BACKGROUND

The present study aimed to investigate the effect of cnidium lactone on ovariectomy (OVX)-induced bone loss and determine whether it exerts its effects by mediating the estrogen receptor-α (ERα)/bone morphogenetic protein-2 (BMP-2)/Smad signaling pathways.

METHODS

Fifty-five female rats were randomly assigned to the following treatment groups: the OVX group, the sham-operated (sham) group, and groups treated with cnidium lactone at different doses (10 mg/kg/day, 20 mg/kg/day, 30 mg/kg/day). Treatments were administered for 60 days. Search Tool for Interacting Chemicals (STITCH; http://stitch.embl.de) was used to identify the interaction between cnidium lactone and target proteins. Bone mineral density (BMD), mechanical strength, serum osteoblastic and osteoclastic markers, and hematoxylin and eosin (HE) staining of the distal femur were evaluated. Moreover, western blot analyses were also performed to evaluate the effect of cnidium lactone on the ERα/BMP-2/Smad signaling pathway.

RESULTS

Cnidium lactone treatment was associated with an increase in the BMD of the distal femur compared to that of the OVX group. Moreover, cnidium lactone significantly increased biomechanical properties in a dose-dependent manner compared to those of the OVX group (p < 0.05). Treatment with cnidium lactone significantly enhanced the BMP-2/Smad signaling pathway by up-regulating the expression of ERα, BMP-2, p-Smad1 and p-Smad4. Cnidium lactone treatment improved the microstructure of trabecular bone in the distal femurs of OVX rats, as shown by HE staining.

CONCLUSIONS

Cnidium lactone exerts potent antiosteoporotic activity in ovariectomized mice, and the underlying molecular mechanism may be related to the ERα/BMP-2/Smad signaling pathways.