New horizons in treatment of osteoporosis

Osteoporosis management-current and future perspectives - A systemic review

Introduction

Osteoporosis is a geriatric metabolic ailment distinguished by low bone mineral density (BMD) and strength with enhanced micro-architectural retrogression of the extracellular matrix, further increasing bone fragility risk. Osteoporotic fractures and associated complications become common in women and men after 55 and 65 years, respectively. The loss in BMD markedly enhances the risk of fracture, non-skeletal injury, and subsequent pain, adversely affecting the quality of life.

Methods

Data summarised in this review were sourced and summarised, including contributions from 2008 to 2023, online from scientific search engines, based on scientific inclusion and exclusion criteria.

Results

Biochemical serum markers such as BALP, collagen, osteocalcin, and cathepsin-K levels can reveal the osteoporotic status. DEXA scan techniques evaluate the whole body's BMD and bone mineral content (BMC), crucial in osteoporosis management. Anabolic and anti-osteoporotic agents are commonly used to enhance bone formation, minimize bone resorption, and regulate remodelling. The challenges and side effects of drug therapy can be overcome by combining the various drug moieties.

Conclusion

The current review discusses the management protocol for osteoporosis, ranging from lifestyle modification, including physical exercise, pharmaceutical approaches, drug delivery applications, and advanced therapeutic possibilities of AI and machine learning techniques to reduce osteoporosis complications and fracture risk.

Natural Compounds for Bone Remodeling: A Computational and Experimental Approach Targeting Bone Metabolism-Related Proteins

Osteoporosis, characterized by reduced bone density and increased fracture risk, affects over 200 million people worldwide, predominantly older adults and postmenopausal women. The disruption of the balance between bone-forming osteoblasts and bone-resorbing osteoclasts underlies osteoporosis pathophysiology. Standard treatment includes lifestyle modifications, calcium and vitamin D supplementation and specific drugs that either inhibit osteoclasts or stimulate osteoblasts. However, these treatments have limitations, including side effects and compliance issues. Natural products have emerged as potential osteoporosis therapeutics, but their mechanisms of action remain poorly understood. In this study, we investigate the efficacy of natural compounds in modulating molecular targets relevant to osteoporosis, focusing on the Mitogen-Activated Protein Kinase (MAPK) pathway and the gut microbiome's influence on bone homeostasis. Using an in silico and in vitro methodology, we have identified quercetin as a promising candidate in modulating MAPK activity, offering a potential therapeutic perspective for osteoporosis treatment.

Marantodes pumilum (Kacip Fatimah) Aqueous Extract Enhances Osteoblast and Suppresses Osteoclast Activities in Cancellous Bone of a Rat Model of Postmenopause

Evidence pointed towards the benefits of Marantodes pumilum in treating osteoporosis after menopause; however, the detailed mechanisms still have not been explored. Therefore, this study aims to identify the molecular mechanisms underlying M. pumilum's bone-protective effect via the involvement of RANK/RANKL/OPG and Wnt/β-catenin signaling pathways. Ovariectomized adult female rats were given M. pumilum leaf aqueous extract (MPLA) (50 and 100 mg/kg/day) and estrogen (positive control) orally for twenty-eight consecutive days. Following the treatment, rats were sacrificed, and femur bones were harvested. Blood was withdrawn for analysis of serum Ca2+, PO43-, and bone alkaline phosphatase (BALP) levels. The bone microarchitectural changes were observed by H&E and PAS staining and distribution and expression of RANK/RANKL/OPG and Wnt3a/β-catenin and its downstream proteins were determined by immunohistochemistry, immunofluorescence, Western blot, and real-time PCR. MPLA treatment increased serum Ca2+ and PO43- levels and reduced serum BALP levels (p < 0.05). Besides, deterioration in cancellous bone microarchitecture and the loss of bone glycogen and collagen content were mitigated by MPLA treatment. Levels of RANKL, Traf6, and NF-kB but not RANK in bone were decreased; however, levels of OPG, Wnt3a, LRP-5, Frizzled, Dvl, β-catenin, RUNX, and Bmp-2 in bone were increased following treatment with MPLA. In conclusion, MPLA helps to protect against bone deterioration in estrogen deficiency state and thus, this herb could potentially be used to ameliorate osteoporosis in women after menopause.

The relationship between caffeine and its metabolites and bone mineral density in postmenopausal women: a cross-sectional analysis from the NHANES database

We aim to explore the association between caffeine and its metabolites and bone mineral density (BMD) in postmenopausal women. Data of 4286 postmenopausal women were extracted from the National Health and Nutrition Examination Survey (NHANES) database in 2009-14 in this cross-sectional study. Weighted linear regression and stepwise regression analyses were used to screen the covariates. Weighted univariate and multivariate linear regression analyses were used to explore the associations between caffeine and its metabolites and BMD. The evaluation index was estimated value (β) with 95 % confidence intervals (CIs). We also explored these relationships in age subgroups. The median BMD level among the eligible women was 0⋅7 gm/cm2. After adjusting for covariates including age, body mass index (BMI), fat intake, Calcium (Ca) supplements, diabetes mellitus (DM), angina pectoris, parental history of osteoporosis (OP), anti-osteoporosis therapy, poverty income ratio (PIR), vitamin D (VD) supplements, coronary heart disease (CHD), and previous fracture, we found that caffeine intake was not significantly related to the BMD reduction (β = 0, P = 0⋅135). However, caffeine metabolites, including MethyluricAcid3, MethyluricAcid7, MethyluricAcid37, Methylxanthine3, and Methylxanthine37, were negatively associated with the BMD (all P < 0⋅05). In addition, MethyluricAcid37 and Methylxanthine37 were negatively associated with BMD in females aged <65 years old, while MethyluricAcid3 and Methylxanthine3 were noteworthy in those who aged ≥65 years old. The roles of caffeine and its metabolites in BMD reduction and OP in postmenopausal women needed further exploration.

The potential pharmacological mechanism of prunetin against osteoporosis: transcriptome analysis, molecular docking, and experimental approaches

BACKGROUND

Prunetin is an O-methylated isoflavone, known for its beneficial properties. However, its specific pharmacological effects in the treatment of osteoporosis (OP) remain poorly understood. This study aims to elucidate the mechanisms underlying the antiosteoporotic effects of prunetin through a combination of bioinformatics analysis and cell experiments.

METHODS

We gathered predicted targets of prunetin from various online platforms. Differential expression analysis of mRNAs in patients with OP was conducted using the Limma package, based on the GSE35959 dataset. A PPI network diagram was visualized and analyzed using Cytoscape 3.7.2 software. Molecular docking was employed to assess the binding affinity between ligands and receptors, and selected key genes were further validated through cell experiments.

RESULTS

A total of 4062 differentially expressed genes (DEGs) were identified from the GSE35959 dataset. Among these, 58 genes were found to overlap with the targets of prunetin, indicating their potential as therapeutic targets. The enrichment analysis indicated these targets were mainly enriched in MAPK, FoxO, and mTOR signaling pathways. The molecular docking analysis demonstrated that prunetin exhibited strong binding activity with the core targets. Furthermore, cell experiments revealed that prunetin effectively reversed the expression levels of ALB, ESR1, PTGS2, and FGFR1 mRNA in MC3T3-E1 cells treated with dexamethasone (DEX).

CONCLUSION

Our research revealed the multi-pathway and multi-target features of prunetin in treating OP, shedding light on the potential mechanisms underlying the effectiveness of prunetin against OP. These findings serve as a theoretical foundation for future drug development in this field.

Generic Platform for the Multiplexed Targeted Electrochemical Detection of Osteoporosis-Associated Single Nucleotide Polymorphisms Using Recombinase Polymerase Solid-Phase Primer Elongation and Ferrocene-Modified Nucleoside Triphosphates

Osteoporosis is a multifactorial disease influenced by genetic and environmental factors, which contributes to an increased risk of bone fracture, but early diagnosis of this disease cannot be achieved using current techniques. We describe a generic platform for the targeted electrochemical genotyping of SNPs identified by genome-wide association studies to be associated with a genetic predisposition to osteoporosis. The platform exploits isothermal solid-phase primer elongation with ferrocene-labeled nucleoside triphosphates. Thiolated reverse primers designed for each SNP were immobilized on individual gold electrodes of an array. These primers are designed to hybridize to the SNP site at their 3'OH terminal, and primer elongation occurs only where there is 100% complementarity, facilitating the identification and heterozygosity of each SNP under interrogation. The platform was applied to real blood samples, which were thermally lysed and directly used without the need for DNA extraction or purification. The results were validated using Taqman SNP genotyping assays and Sanger sequencing. The assay is complete in just 15 min with a total cost of 0.3€ per electrode. The platform is completely generic and has immense potential for deployment at the point of need in an automated device for targeted SNP genotyping with the only required end-user intervention being sample addition.

Review on the protective activity of osthole against the pathogenesis of osteoporosis

Osteoporosis (OP), characterized by continuous bone loss and increased fracture risk, has posed a challenge to patients and society. Long-term administration of current pharmacological agents may cause severe side effects. Traditional medicines, acting as alternative agents, show promise in treating OP. Osthole, a natural coumarin derivative separated from Cnidium monnieri (L.) Cusson and Angelica pubescens Maxim. f., exhibits protective effects against the pathological development of OP. Osthole increases osteoblast-related bone formation and decreases osteoclast-related bone resorption, suppressing OP-related fragility fracture. In addition, the metabolites of osthole may exhibit pharmacological effectiveness against OP development. Mechanically, osthole promotes osteogenic differentiation by activating the Wnt/β-catenin and BMP-2/Smad1/5/8 signaling pathways and suppresses RANKL-induced osteoclastogenesis and osteoclast activity. Thus, osthole may become a promising agent to protect against OP development. However, more studies should be performed due to, at least in part, the uncertainty of drug targets. Further pharmacological investigation of osthole in OP treatment might lead to the development of potential drug candidates.

Mechanistic advances in osteoporosis and anti-osteoporosis therapies

Osteoporosis is a type of bone loss disease characterized by a reduction in bone mass and microarchitectural deterioration of bone tissue. With the intensification of global aging, this disease is now regarded as one of the major public health problems that often leads to unbearable pain, risk of bone fractures, and even death, causing an enormous burden at both the human and socioeconomic layers. Classic anti-osteoporosis pharmacological options include anti-resorptive and anabolic agents, whose ability to improve bone mineral density and resist bone fracture is being gradually confirmed. However, long-term or high-frequency use of these drugs may bring some side effects and adverse reactions. Therefore, an increasing number of studies are devoted to finding new pathogenesis or potential therapeutic targets of osteoporosis, and it is of great importance to comprehensively recognize osteoporosis and develop viable and efficient therapeutic approaches. In this study, we systematically reviewed literatures and clinical evidences to both mechanistically and clinically demonstrate the state-of-art advances in osteoporosis. This work will endow readers with the mechanistical advances and clinical knowledge of osteoporosis and furthermore present the most updated anti-osteoporosis therapies.

Roles of sex hormones in mediating the causal effect of vitamin D on osteoporosis: A two-step Mendelian randomization study

Background

Although 25-hydroxyvitamin D [25(OH)D] is a risk factor for osteoporosis, it is not clear whether sex hormones mediate this casual association. We aimed to explore how sex hormones affect the association between 25(OH)D and osteoporosis to provide meaningful insights on the underlying mechanisms from a genetic perspective.

Methods

Genetic variations in 25(OH)D, total testosterone (TT), androstenedione (A4), estradiol (E2), and testosterone/17β-estradiol (T/E2) were determined through summary statistics. Taking osteoporosis as the outcome (FinnGen biobank, 332,020 samples), we conducted a Mendelian randomization (MR) analysis to establish the association between 25(OH)D and these sex hormones. The two-step MR analysis quantified the mediatory effects of sex hormones on osteoporosis. The results were further verified by pleiotropy and heterogeneity analyses.

Results

MR results showed that 25(OH)D (OR= 1.27, p = 0.04) and TT (OR= 1.25, p = 0.04) had a causal effect on osteoporosis. No significant associations were observed between the other sex hormones (A4, E2, and T/E2) and osteoporosis (p&gt;0.05). Sensitivity analysis (p&gt;0.05) confirmed the robustness of the MR results. The two-step MR analysis provided evidence that the mediatory effect of TT was 0.014 (the percentage of TT mediation was 5.91%). Moreover, the direct effect of 25(OH)D on osteoporosis was 0.221. A4, E2, and T/E2 were not considered as potential mediators of the role of 25(OH)D as a risk factor for OP.

Conclusion

This study, through MR analysis, showed that TT mediates the causal effect of 25(OH)D on osteoporosis. Interventions targeting TT, therefore, have the potential to substantially reduce the burden of osteoporosis attributable to high 25(OH)D.

Comparison of pharmacokinetics, pharmacodynamics, safety, and immunogenicity of teriparatide biosimilar with EU- and US-approved teriparatide reference products in healthy men and postmenopausal women

Biosimilar teriparatide (INTG-8) was tested in a healthy population of males and postmenopausal females to assess pharmacokinetic bioequivalence to originator teriparatide comparator products. Primary pharmacokinetic comparison confirmed bioequivalence. Pharmacodynamics, safety, and tolerability were comparable to the originator products. INTG-8 was therefore confirmed to be biosimilar to originator products.

INTRODUCTION

The purpose of this present study was to demonstrate pharmacokinetic (PK) equivalence of a biosimilar teriparatide (INTG8) to EU- and US-approved teriparatide reference products in healthy men and postmenopausal women. Secondary objectives included comparison of the pharmacodynamics (PD), safety, and tolerability.

METHODS

One hundred and five subjects randomly (1:1:1) received single subcutaneous 20 μg injection of teriparatide biosimilar, EU- and US-teriparatide on 3 consecutive days in this assessor-blind, three-period, single-dose, crossover study. Maximum serum concentration (C_max), area under the curve (AUC) from time zero to t (AUC_0-t), and AUC from time zero extrapolated to infinity (AUC_0-∞) were primary PK parameters, analyzed by non-compartmental methods. The secondary PD endpoints were maximum observed effect (E_max), area under the effect curve (AUE) from time zero to the last measurable concentration (AUE_0-t), and time to maximum observed effect (Tmax) for total serum calcium levels. Safety, tolerability, and immunogenicity were also evaluated. This study was registered with ctri.nic.in/ (CTRI/2020/10/028627) on 26 October 2020.

RESULTS

Baseline demographics were similar across the three-treatment sequence groups. The 90% confidence intervals (CI) for the geometric mean ratios (test:reference) of Cmax, AUC_0-t, and AUC_0-∞ were within the predefined bioequivalence criterion of 80.00% to 125.00%, which demonstrated PK equivalence of teriparatide biosimilar to EU- and US-teriparatide for all primary endpoints. The PD comparability was demonstrated by similar serum calcium levels. Study treatments were generally well tolerated and showed no meaningful differences in safety or immunogenicity profiles. There were no deaths, or serious AEs were reported during this study.

CONCLUSION

The study demonstrated PK bioequivalence of teriparatide biosimilar to the EU- and US-teriparatide reference products with comparable PD, safety, and immunogenicity profiles.

CircZNF367 suppresses osteogenic differentiation of human bone marrow mesenchymal stromal/stem cells via reducing HuR-mediated mRNA stability of LRP5

Osteoporosis is a highly prevalent disease characterized by bone mass loss and structural deterioration. There are evidences that altered differentiation of human bone marrow mesenchymal stromal/stem cells (hBMSCs) is a major cause for osteoporosis. Recent studies suggest that circular RNAs (circRNAs) are dysregulated in osteoporosis patients and involved in the pathogenesis of osteoporosis. In the present study, we are aimed to analyze the circRNA expression profiles in osteoporosis patients and identify potential circRNAs that involved in the differentiation of hBMSCs during osteoporosis. Transcriptome RNA-sequencing was conducted to search for differentially expressed circRNAs. Transwell assay, ARS and ALP staining, and ectopic bone formation model were performed to evaluate osteogenic differentiation of hBMSCs. RNA pull-down assay, RNA immunoprecipitation, western blot, and in vitro binding assay were conducted to evaluate the interaction of circRNAs and RNA-binding protein HuR. We found that hsa_circ_0008842 (designated as circZNF367) was upregulated in osteoporosis patients and decreased in hBMSCs during osteogenic differentiation. CircZNF367 overexpression suppressed migration, invasion and osteogenic differentiation of hBMSCs in vitro and in vivo. In comparison, knockdown of circZNF367 promoted migration, invasion and osteogenic differentiation of hBMSCs. CircZNF367 could interact with the RNA-binding protein HuR, thus reduced the mRNA stability of LRP5. Furthermore, HuR overexpression or LRP5 restoration abrogated the effects of circZNF367 overexpression on osteogenic differentiation of hBMSCs. Our results indicated that circZNF367 played a role in osteogenic differentiation of hBMSCs via reducing HuR-mediated mRNA stability of LRP5.

Does Zoledronic Acid Provide a Good Clinical Outcome in Patients With Chronic Back Pain Associated With Vertebral Osteoporosis?

Background Osteoporosis is a chronic, progressive, systemic condition of the skeletal tissue that is characterized by reduced bone density, microarchitecture deterioration, and fragile bones, making osteoporotic fractures or fragility fractures more likely to occur. This condition often remains asymptomatic and undiagnosed until it presents with fragility fractures. The condition is associated with a significant socioeconomic burden with disability, morbidity, and mortality. Therefore, early diagnosis, as well as treatment, is needed to prevent fractures. Intravenous zoledronic is an effective bisphosphonate with high patient compliance due to once-yearly dosing. The present study aims to determine whether zoledronic acid effectively treats chronic back pain in people with osteoporosis. Materials and methods Seventy patients above the age of 60 years presented with complaints of chronic low back aches to the outpatient department of orthopedics, R L Jalappa Hospital & Research Centre attached to Sri Devaraj Urs Medical College. The study was conducted between November 2016 and November 2018. Results All the patients found excellent clinical improvement following zoledronic acid infusion in early and long-term follow-ups. Additionally, it was found that zoledronic acid's effectiveness was excellent, with significant improvement in bone mineral density (BMD), T-score, and Z-score. Conclusion Early diagnosis and treatment of vertebral osteoporosis is the most important factor in preventing fragility fractures. Zoledronic acid, an antiresorptive drug with better compliance, is very effective in controlling low back pain, improving bone mineral density, and preventing the occurrence of atraumatic fragility fractures. With all the above factors, zoledronic acid is a preferable bisphosphonate for the treatment and prevention of osteoporosis compared to other modalities of treatment of osteoporosis.

Human serum albumin-based nanoparticles alter raloxifene administration and improve bioavailability

Osteoporosis is a disease that reduces bone mass and microarchitecture, which makes bones fragile. Postmenopausal osteoporosis occurs due to estrogen deficiency. Raloxifene is a selective estrogen receptor modulator used to treat postmenopausal osteoporosis. However, it has a low bioavailability, which requires long-term, high-dose raloxifene administration to be effective and causes several side effects. Herein, raloxifene was encapsulated in human serum albumin (HSA)-based nanoparticles (Ral/HSA/PSS NPs) as an intravenous-injection pharmaceutical formulation to increase its bioavailability and reduce the treatment dosage and time. In vitro results indicated that raloxifene molecules were well distributed in HSA-based nanoparticles as an amorphous state, and the resulting raloxifene formulation was stabile during long-term storage duration. The Ral/HSA/PSS NPs were both biocompatible and hemocompatible with a decreased cytotoxicity of high-dose raloxifene. Moreover, the intravenous administration of the prepared Ral/HSA/PSS NPs to rats improved raloxifene bioavailability and improved its half-life in plasma. These raloxifene-loaded nanoparticles may be a potential nanomedicine candidate for treating postmenopausal osteoporosis with lower raloxifene dosages.

The Role of Prunes in Modulating Inflammatory Pathways to Improve Bone Health in Postmenopausal Women

The prevalence of osteoporosis among women aged 50 y and older is expected to reach 13.6 million by 2030. Alternative nonpharmaceutical agents for osteoporosis, including nutritional interventions, are becoming increasingly popular. Prunes (dried plums; Prunus domestica L.) have been studied as a potential whole-food dietary intervention to mitigate bone loss in preclinical models of osteoporosis and in osteopenic postmenopausal women. Sixteen preclinical studies using in vivo rodent models of osteopenia or osteoporosis have established that dietary supplementation with prunes confers osteoprotective effects both by preventing and reversing bone loss. Increasing evidence from 10 studies suggests that, in addition to antiresorptive effects, prunes exert anti-inflammatory and antioxidant effects. Ten preclinical studies have found that prunes and/or their polyphenol extracts decrease malondialdehyde and NO secretion, increase antioxidant enzyme expression, or suppress NF-κB activation and proinflammatory cytokine production. Two clinical trials have investigated the impact of dried plum consumption (50-100 g/d for 6-12 mo) on bone health in postmenopausal women and demonstrated promising effects on bone mineral density and bone biomarkers. However, less is known about the impact of prune consumption on oxidative stress and inflammatory mediators in humans and their possible role in modulating bone outcomes. In this review, the current state of knowledge on the relation between inflammation and bone health is outlined. Findings from preclinical and clinical studies that have assessed the effect of prunes on oxidative stress, inflammatory mediators, and bone outcomes are summarized, and evidence supporting a potential role of prunes in modulating inflammatory and immune pathways is highlighted. Key future directions to bridge the knowledge gap in the field are proposed.

Alpinetin ameliorates bone loss in LPS-induced inflammation osteolysis via ROS mediated P38/PI3K signaling pathway

BACKGROUND AND OBJECTIVE

Bone loss occurs in several inflammatory diseases because of chronic persistent inflammation that activates osteoclasts (OCs) to increase bone resorption. Currently available antiresorptive drugs have severe side effects or contraindications. Herein, we explored the effects and mechanism of Alpinetin (Alp) on receptor activator of nuclear factor κB ligand (RANKL)-mediated OCs differentiation, function, and in inflammatory osteolysis of mice.

METHOD

Primary mouse bone marrow-derived macrophages (BMMs) induced by RANKL and macrophage colony-stimulating factor (M-CSF) were utilized to test the impact of Alp on OCs differentiation, function, and intracellular reactive oxygen species (ROS) production, respectively. Expression of oxidant stress relevant factors and OCs specific genes were assessed via real-time quantitative PCR. Further, oxidative stress-related factors, NF-κB, MAPK, PI3K/AKT/GSK3-β, and NFATc1 pathways were examined via Western blot. Finally, LPS-induced mouse calvarial osteolysis was used to investigate the effect of Alp on inflammatory osteolysis in vivo.

RESULT

Alp suppressed OCs differentiation and resorption function, and down-regulated the ROS production. Alp inhibited IL-1β, TNF-α and osteoclast-specific gene transcription. It also blocked the gene and protein expression of Nox1 and Keap1, but enhanced Nrf2, CAT, and HO-1 protein levels. Additionally, Alp suppressed the phosphorylation of PI3K and P38, and restrained the expression of osteoclast-specific gene Nfatc1 and its auto-amplification, hence minimizing LPS-induced osteolysis in mice.

CONCLUSION

Alp is a novel candidate or therapeutics for the osteoclast-associated inflammatory osteolytic ailment.

Deciphering the molecular mechanism underlying the effects of epimedium on osteoporosis through system bioinformatic approach

Epimedium has gained widespread clinical application in Traditional Chinese Medicine, with the functions of promoting bone reproduction, regulating cell cycle and inhibiting osteoclastic activity. However, its precise cellular pharmacological therapeutic mechanism on osteoporosis (OP) remains elusive. This study aims to elucidate the molecular mechanism of epimedium in the treatment of OP based on system bioinformatic approach. Predicted targets of epimedium were collected from TCMSP, BATMAN-TCM and ETCM databases. Differentially expressed mRNAs of OP patients were obtained from Gene Expression Omnibus database by performing Limma package of R software. Epimedium-OP common targets were obtained by Venn diagram package for further analysis. The protein-protein interaction network was constructed using Cytoscape software. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were carried out by using clusterProfiler package. Molecular docking analysis was conducted by AutoDock 4.2 software to validate the binding affinity between epimedium and top 3 proteins based on the result of protein-protein interaction. A total of 241 unique identified epimedium targets were screened from databases, of which 62 overlapped with the targets of OP and were considered potential therapeutic targets. The results of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that these targets were positive regulation of cell cycle, cellular response to oxidative stress and positive regulation of cell cycle process as well as cellular senescence, FoxO, PI3K-Akt, and NF-kappa B signaling pathways. Molecular docking showed that epimedium have a good binding activity with key targets. Our study demonstrated the multitarget and multi-pathway characteristics of epimedium on OP, which elucidates the potential mechanisms of epimedium against OP and provides theoretical basis for further drug development.

Fucoxanthin: A Promising Phytochemical on Diverse Pharmacological Targets

Fucoxanthin (FX) is a special carotenoid having an allenic bond in its structure. FX is extracted from a variety of algae and edible seaweeds. It has been proved to contain numerous health benefits and preventive effects against diseases like diabetes, obesity, liver cirrhosis, malignant cancer, etc. Thus, FX can be used as a potent source of both pharmacological and nutritional ingredient to prevent infectious diseases. In this review, we gathered the information regarding the current findings on antimicrobial, antioxidant, anti-inflammatory, skin protective, anti-obesity, antidiabetic, hepatoprotective, and other properties of FX including its bioavailability and stability characteristics. This review aims to assist further biochemical studies in order to develop further pharmaceutical assets and nutritional products in combination with FX and its various metabolites.

Bone Health in Children with Rheumatic Disorders: Focus on Molecular Mechanisms, Diagnosis, and Management

Bone is an extremely dynamic and adaptive tissue, whose metabolism and homeostasis is influenced by many different hormonal, mechanical, nutritional, immunological and pharmacological stimuli. Genetic factors significantly affect bone health, through their influence on bone cells function, cartilage quality, calcium and vitamin D homeostasis, sex hormone metabolism and pubertal timing. In addition, optimal nutrition and physical activity contribute to bone mass acquisition in the growing age. All these factors influence the attainment of peak bone mass, a critical determinant of bone health and fracture risk in adulthood. Secondary osteoporosis is an important issue of clinical care in children with acute and chronic diseases. Systemic autoimmune disorders, like juvenile idiopathic arthritis, can affect the skeletal system, causing reduced bone mineral density and high risk of fragility fractures during childhood. In these patients, multiple factors contribute to reduce bone strength, including systemic inflammation with elevated cytokines, reduced physical activity, malabsorption and nutritional deficiency, inadequate daily calcium and vitamin D intake, use of glucocorticoids, poor growth and pubertal delay. In juvenile arthritis, osteoporosis is more prominent at the femoral neck and radius compared to the lumbar spine. Nevertheless, vertebral fractures are an important, often asymptomatic manifestation, especially in glucocorticoid-treated patients. A standardized diagnostic approach to the musculoskeletal system, including prophylaxis, therapy and follow up, is therefore mandatory in at risk children. Here we discuss the molecular mechanisms involved in skeletal homeostasis and the influence of inflammation and chronic disease on bone metabolism.

The Brown Algae Ishige sinicola Extract Ameliorates Ovariectomy-Induced Bone Loss in Rats and Suppresses Osteoclastogenesis through Downregulation of NFATc1/c-Fos

Osteoporosis is characterized by reduction in bone mass and microarchitectural deterioration of the bone, which causes bone fragility and fracture susceptibility. Ishige sinicola, a brown alga, reportedly affects osteoblast differentiation. However, its protective effect on estrogen deficiency-induced bone loss has not been elucidated. This study aimed to investigate the effect of I. sinicola extract (ISE) on ovariectomy (OVX)-induced bone loss in vivo and osteoclastogenesis in vitro. Female Sprague-Dawley rats were randomly assigned to the sham-operated (SHAM) group and four OVX subgroups: SHAM, OVX, ISE20 (20 mg/kg), ISE200 (200 mg/kg), and estradiol (10 μg/kg). After 6 weeks of treatment, the bone mineral density (BMD), femur indices, and serum biomarker levels were measured. Furthermore, the effects of ISE on osteoclastogenesis and the expression of osteoclast-specific markers were measured. ISE administration improved the trabecular bone structure, bone biomechanical properties, BMD, and bone mineralization degree. In addition, the levels of serum bone turnover markers were decreased in the ISE group compared with those in the OVX group. Moreover, ISE inhibited osteoclast formation by downregulating NFATc1, TRAP, c-Src, c-Fos, and cathepsin K without any cytotoxic effects on RANKL-induced osteoclast formation. Therefore, we suggest that ISE has therapeutic potential in postmenopausal osteoporosis.

Iron and 25-hydroxyvitamin D in postmenopausal women with osteoporosis

Iron and vitamin D deficiencies are some of the most common health problems in the world. Iron is essential in oxygen transport and participates in many enzymatic systems in the body, with important roles in vitamin D metabolism. Osteoporosis is one of the most prevalent chronic disease of the elderly in the world as well as in the Saudi population. The relationship between iron, vitamin D deficiency and bone health comes from clinical observations in iron overload patients who suffered bone loss. The opposite scenario, whether iron and vitamin D deficiencies affect bone metabolism, has not been fully addressed. This is of great interest, as this nutrient deficiency is a worldwide public health problem and at the same time osteoporosis and bone alterations are highly prevalent. The relationship between 25(OH)D and iron deficiencies with osteoporosis is unknown up to date. This review presents the current knowledge on nutritional iron and vitamin D deficiencies in bone remodeling, and discuss the link between iron and bone metabolism among postmenopausal women. Finally, it is hypothesized that chronic iron and vitamin D deficiencies induces bone resorption and risk of osteoporosis, thus complete recovery from anemia and its prevention should be promoted in order to improve quality of life including bone health. Several mechanisms are implicated; hence, further investigation on the possible impact of iron and vitamin D deficiencies on the development of osteoporosis is needed.

Effect of 50-Hertz Sinusoidal Vibration on the Uterus in Ovariectomy-Induced Osteoporotic Rats

Objective

To evaluate the influence of sinusoidal vibration (50-Hertz) stimulation on the uterus of osteoporotic rats.

Methods

We constructed an osteoporosis rat model by ovariectomy (OVX). 36 3-month-old Sprague Dawley rats were randomly divided into the control group, vibrating group, sham operation group, sham operation vibrating group, OVX group, and OVX vibrating group (n = 6 per group). Rats started to vibrate one week after the operation: one 10 minutes 50-Hertz sinusoidal vibration per day, except for Saturday and Sunday. In the second, 8, and 12 week after vibration stimulation, rats were sacrificed in batches. And then, the uteruses were taken out to measure the wet weight and calculate uterus relative wet weight.

Results

Compared with the control group, OVA induced a significant increase in wet weight and relative wet weight in rat uterus. The vibration was to the uterus wet weight and the uterus relative wet weight in ovariectomized rats and at the same time had no significant effect, but the 12-week prolonged vibration can significantly reduce the uterus wet weight and the uterus relative wet weight in ovariectomized rats than 2 weeks.

Conclusions

The uterus wet weight and the uterus relative wet weight were increased in the OVA-induced osteoporosis rats. The 50-Hertz sinusoidal vibration had no significant effect on the uterus wet weight and the uterus relative wet weight in the ovariectomized rats at the same time, but 12 weeks of vibration can significantly reduce the uterine wet weight and uterine relative wet weight of ovariectomized rats. And the uterus relative wet weight can be used as a new indicator of stimulating the uterus.

A novel hierarchical biofunctionalized 3D-printed porous Ti6Al4V scaffold with enhanced osteoporotic osseointegration through osteoimmunomodulation

Background

Femoral stem of titanium alloy has been widely used for hip arthroplasty with considerable efficacy; however, the application of this implant in patients with osteoporosis is limited due to excessive bone resorption. Macrophages participate in the regulation of inflammatory response and have been a topic of increasing research interest in implant field. However, few study has explored the link between macrophage polarization and osteogenic–osteoclastic differentiation. The present study aims to develop a novel hierarchical biofunctionalized 3D-printed porous Ti6Al4V scaffold with enhanced osteoporotic osseointegration through immunotherapy.

Method

To improve the osteointegration under osteoporosis, we developed a hierarchical biofunctionalized 3D-printed porous Ti6Al4V scaffold (PT). Biomimetic extracellular matrix (ECM) was constructed inside the interconnected pores of PT in micro-scale. And in nano-scale, a drug cargo icariin@Mg-MOF-74 (ICA@MOF) was wrapped in ECM-like structure that can control release of icariin and Mg²⁺.

Results

In this novel hierarchical biofunctionalized 3D-printed porous Ti6Al4V scaffold, the macroporous structure provides mechanical support, the microporous structure facilitates cell adhesion and enhances biocompatibility, and the nanostructure plays a biological effect. We also demonstrate the formation of abundant new bone at peripheral and internal sites after intramedullary implantation of the biofunctionalized PT into the distal femur in osteoporotic rats. We further find that the controlled-release of icariin and Mg²⁺ from the biofunctionalized PT can significantly improve the polarization of M0 macrophages to M2-type by inhibiting notch1 signaling pathway and induce the secretion of anti-inflammatory cytokines; thus, it significantly ameliorates bone metabolism, which contributes to improving the osseointegration between the PT and osteoporotic bone.

Conclusion

The therapeutic potential of hierarchical PT implants containing controlled release system are effective in geriatric orthopaedic osseointegration.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01277-0.

GIP and GLP-2 together improve bone turnover in humans supporting GIPR-GLP-2R co-agonists as future osteoporosis treatment

The intestinal hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-2 (GLP-2) are key regulators of postprandial bone turnover in humans. We hypothesized that GIP and GLP-2 co-administration would provide stronger effect on bone turnover than administration of the hormones separately, and tested this using subcutaneous injections of GIP and GLP-2 alone or in combination in humans. Guided by these findings, we designed series of GIPR-GLP-2R co-agonists as template for new osteoporosis treatment. The clinical experiment was a randomized cross-over design including 10 healthy men administered subcutaneous injections of GIP and GLP-2 alone or in combination. The GIPR-GLP-2R co-agonists were characterized in terms of binding and activation profiles on human and rodent GIP and GLP-2 receptors, and their pharmacokinetic (PK) profiles were improved by dipeptidyl peptidase-4 protection and site-directed lipidation. Co-administration of GIP and GLP-2 in humans resulted in an additive reduction in bone resorption superior to each hormone individually. The GIPR-GLP-2R co-agonists, designed by combining regions of importance for cognate receptor activation, obtained similar efficacies as the two native hormones and nanomolar potencies on both human receptors. The PK-improved co-agonists maintained receptor activity along with their prolonged half-lives. Finally, we found that the GIPR-GLP-2R co-agonists optimized toward the human receptors for bone remodeling are not feasible for use in rodent models. The successful development of potent and efficacious GIPR-GLP-2R co-agonists, combined with the improved effect on bone metabolism in humans by co-administration, support these co-agonists as a future osteoporosis treatment.

Tilapia nilotica Head Lipids Improved Bone Loss by Regulating Inflammation and Serum Metabolism Through Gut Microbiota in Ovariectomized Rats

Osteoporosis is a global health problem, and it is of great significance to replace the drugs with natural functional factors. In this study, we investigated the antiosteoporotic activity of lipids prepared from Tilapia nilotica fish head lipids (THLs) in the ovariectomized osteoporosis rats. THLs are composed of neutral lipids (NL, 77.84%), phospholipids (PL, 11.86%), and glycolipids (GL, 6.47%). There were apparent differences in the fatty acid composition of disparate components, and PL contains the most abundant Ω-3 polyunsaturated fatty acids. The results proved that THLs could improve bone microstructure, increase bone mineral density, and decrease bone resorption. To illustrate the antiosteoporotic mechanism, we analyzed the changes in gut microbial communities, proinflammation factors, serum metabolites, and metabolic pathways. Further study on gut microbiota showed that THLs significantly decreased the content of Alistipes in the gut and dramatically increased the beneficial bacteria such as Oscillospira, Roseburia, and Dubosiella. Meanwhile, proinflammation factors of serum in OVX rats decreased significantly, and metabolites were changed. Therefore, we speculated that THLs improved bone loss through reducing inflammation and changing the metabolites and metabolic pathways such as arachidonic acid metabolism and primary bile acid metabolism, etc., by altering gut microbiota. The results indicated that THLs could be a functional factor with antiosteoporotic activity.

Polygalacto-fucopyranose biopolymer structured nanoparticle conjugate attenuates glucocorticoid-induced osteoporosis: An in vivo study

Naturally occurring polysaccharide-structured nanoparticles have developed as promising materials for treatment of bone health disorders. Silver nanoparticle (ST-AgNP) structured from sulfated polygalacto-fucopyranose comprising of recurring structural entities of 2-SO3-α-(1 → 3)-fucopyranose and 6-O-acetyl-β-(1 → 4)-galactopyranose isolated from marine macroalga Sargassum tenerrimum demonstrated potential activities associated with osteogenesis. Subsequent treatment with ST-AgNP, activity of alkaline phosphatase (63 mU/mg) was raised in osteoblast stem cells (human mesenchymal, hMSC) than that in control (30 mU/mg). Intense growth of mineralized nodule on the surface of hMSC was apparent following treatment with ST-AgNP. Increased population of bone morphogenic protein-2 (23%) and osteocalcin+ cells (50%) on M2 macrophages were apparent following treatment with ST-AgNP (0.25 mg/mL). Glucocorticoid-induced in vivo animal model studies of ST-AgNP exhibited significant recovery of serum biochemical parameters along with serum estradiol and parathyroid hormone compared to disease control. Disease-induced groups treated with ST-AgNP showed the disappearance of osteoporotic cavities in the trabecular bone. Following treatment with ST-AgNP, serum calcium and phosphorus contents were significantly recovered.

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.

Drinking tea before menopause is associated with higher bone mineral density in postmenopausal women

BACKGROUND

Though tea drinking years and menopause stages have been indicated to be related with bone mineral density (BMD), most human studies have not considered the impact of tea drinking beginning time. Whether drinking tea before or after menopause plays a role in BMD is still unclear. This study aims to analyze whether drinking tea before or after menopause influences BMD in Chinese postmenopausal women.

METHODS

A total of 1377 postmenopausal women under 80 years were enrolled from the baseline survey of the Lanxi Cohort Study. Participants were initially categorized into non-tea drinking, tea drinking beginning after menopause and tea drinking beginning before menopause groups. Tea drinking groups were subdivided according to tea drinking frequency, concentration and type. Multiple linear regression models were applied to evaluate associations between tea drinking before or after menopause and BMD and the impacts of tea drinking frequency, concentration and type on their associations in analyses including all participants. Interactions of tea drinking frequency, concentration and type with drinking tea before or after menopause were further analyzed.

RESULTS

After adjusting for confounding factors, women who began drinking tea before menopause had significantly higher total and regional BMD than non-tea drinking participants and participants who began drinking tea after menopause. Differences in spine BMD were more significant among those who drank tea ≥four times per week. In addition, significant associations between tea drinking and BMD were found among participants who began drinking tea before menopause in both models, irrespective of the concentration and type of tea. No significant associations were found in subgroups of participants who began drinking tea after menopause in either model.

CONCLUSIONS

The results indicate that drinking tea before menopause is related to higher BMD in Chinese postmenopausal women. The relationship is independent of tea drinking concentration and type.

Osteogenic Activity of Lupeol Isolated from Clinacanthus nutans Lindau: Activity and Mode of Action

Clinacanthus nutans Lindau has been traditionally used for healing of bone fragility, but the mechanism of actions has not been clarified yet. In this study, the bone regeneration activity of lupeol derived from C. nutans was assessed using an in vitro model of osteoblast cells MC3T3-E1. The finding revealed that the compound was not significantly toxic to osteoblast cells at concentration of ≤40 μg/mL. Lupeol demonstrated the osteogenic activity through enhancement of alkaline phosphatase (ALP) of osteoblast cells up to 31.2%, 21%, and 12% at concentrations of 5, 10, and 20 µg/mL, respectively ( $p$  < 0.05). Besides, the mineralization activity was increased up to 170, 230, 185, and 117% at concentration of 5, 10, 20, and 40 μg/mL, respectively ( $p$  < 0.05). The marker genes related to osteoblast differentiation evaluated on the expression level in the presence of lupeol, including collagen I (col 1), osteopontin (opn), osterix (osx), and runx2, showed upregulated expression in all the test genes ( $p$  < 0.05). The Western blot analysis demonstrated a clear effect of lupeol on expression of p38/p-p38, and ERK/p-ERK proteins involved in the MAPK signaling pathway. Thus, lupeol isolated from C. nutans exhibited the osteogenic activity by enhancing expression of important markers of osteogenesis, as well as affected the MAPK signaling pathway relating to osteoblast differentiation. This is the first report on the detailed mechanism of action of lupeol on bone regeneration and also explains for the traditional use of this medicinal plant for bone healing.

The mechanism of Epimedin B in treating osteoporosis as revealed by RNA sequencing-based analysis

With the ageing of populations, the management of osteoporosis is a priority of society in general. Epimedin B, a major ingredient of Herba Epimedii, which has the advantages of high content and hypotoxicity has been proved to be effective in preventing osteoporosis in vitro. However, the efficacy and mechanism of Epimedin B on osteoporosis in vivo have not been well elucidated yet. This study aimed to investigate the effects and the potential mechanisms of 8-week repeated oral administration of Epimedin B (10 and 20 mg/kg/day) on a mouse osteoporosis model. Effects of Epimedin B were evaluated by examinations of serum bone turnover markers, bone mineral density, bone microstructure parameters and histopathological section. Epimedin B significantly rose N-terminal propeptide of type I procollagen (P1NP) and dropped C-telopeptide of type I collagen (CTX1). Connectivity density (Conn.D) increased significantly while structure model index (DA) decreased significantly after treated by Epimedin B. Meanwhile, Epimedin B administration significantly increased the number of trabecular bones while significantly decreased the gap between them. Overall, Epimedin B showed beneficial effects on osteoporosis. Furthermore, RNA sequencing-based analysis revealed 5 significantly down-regulated transcripts and 107 significantly up-regulated transcripts between the Epimedin B administration group and the model group. These transcripts were mapped to 15 pathways by KEGG enrichment analysis, of which PI3K-Akt signalling pathway, MAPK signalling pathway and PPAR signalling pathway were most connected to osteoporosis. To conclude, Epimedin B is effective in treating osteoporosis in mice via regulating PI3K-Akt, MAPK and PPAR signalling pathway.

Salvia officinalis Extract and 17β-Estradiol Suppresses Ovariectomy Induced Osteoporosis in Female Rats

&lt;b&gt;Background and Objective:&lt;/b&gt; Osteoporosis is a progressive metabolic disorder characterized by an impaired bone formation that leads to increased morbidity and mortality.&lt;i&gt; Salvia officinalis &lt;/i&gt;is a source of phytoestrogens that could help mitigate the risk of osteoporotic rat fracture by exerting sex hormones. Therefore, the present study was designed to investigate the curative effect of &lt;i&gt;Salvia officinalis &lt;/i&gt;Extract&lt;i&gt; &lt;/i&gt;(SOE) and&lt;i&gt; &lt;/i&gt;17β-estradiol (E&lt;sub&gt;2&lt;/sub&gt;) and their combination&lt;i&gt; &lt;/i&gt;on bone loss in female rats with ovariectomy-induced estrogen deficiency &lt;b&gt;Materials and Methods:&lt;/b&gt; Forty adult female albino rats were divided into five groups, which included Sham control (Sham), ovariectomy (OVX), OVX+SOE, OVX+E&lt;sub&gt;2&lt;/sub&gt; and OVX +SOE+E&lt;sub&gt;2&lt;/sub&gt;.&lt;i&gt; &lt;/i&gt;SOE (10 mL kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt;) and E&lt;sub&gt;2&lt;/sub&gt; (30 μg kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt;) had been daily gavaged in the OVX+SOE, OVX+E&lt;sub&gt;2&lt;/sub&gt; and OVX+SOE+E&lt;sub&gt;2&lt;/sub&gt;, respectively for 6-weeks. &lt;b&gt;Results:&lt;/b&gt; The model of ovariectomy resulted in osteoporosis as demonstrated by the decreased serum Ca, P, vitamin D, E&lt;sub&gt;2&lt;/sub&gt; level associated with a significant increase in PTH levels in comparison to the sham control group. Besides, OVX to rats caused up-regulation in the levels of CTX-1, P1NP, BALP, OC and RANKL comparable to the sham control group. Moreover, SOE and E&lt;sub&gt;2&lt;/sub&gt; significantly modulated the calciotropic parameters and improved all bone turnover markers as well as RANKL as compared to the OVX group. However, Histopathological and immunohistochemical results showed defective mineralization with the destruction of the bone matrix and increased TNF-α expression from the OVX group relative to the treated groups. &lt;b&gt;Conclusion:&lt;/b&gt; These results suggest that both SOE and E&lt;sub&gt;2&lt;/sub&gt; or their combined administration are efficient inhibitors against ovariectomy-induced bone loss in female rats.

In vitro osteogenic activities of sulfated derivative of polysaccharide extracted from Tamarindus indica L

Osteoporosis, one of the most serious public health concerns caused by an imbalance between bone resorption and bone formation, has a major impact on the population. Therefore, finding the effective osteogenic compounds for the treatment of osteoporosis is a promising research approach. In our study, tamarind (Tamarindus indica L.) seed polysaccharide (TSP) extracted from tamarind seed was subjected to synthesize its sulfate derivatives. The ¹H NMR, FT-IR, SEM, monosaccharide compositions and elemental analysis data revealed that tamarind seed polysaccharide sulfate (TSPS) was successfully prepared. As the result, TSPS showed potent effects on inducing osteoblast differentiation via increasing alkaline phosphatase (ALP) activity up to 20% after 10 days and bone mineralization approximately 58% after four weeks at concentration of 20 μg/mL, whereas no statistically increase for both ALP activity and bone mineralization was observed in TSP treatment. Furthermore, TSPS enhanced expression of several marker genes in bone formation. Overall, the obtained data provided novelty on osteogenic compounds originated from TSP of T. indica, as well as scientific fundamentals on drug development and bone tissue engineering for the treatment of osteoporosis and other bone-related diseases.

The Development of Molecular Biology of Osteoporosis

Osteoporosis is one of the major bone disorders that affects both women and men, and causes bone deterioration and bone strength. Bone remodeling maintains bone mass and mineral homeostasis through the balanced action of osteoblasts and osteoclasts, which are responsible for bone formation and bone resorption, respectively. The imbalance in bone remodeling is known to be the main cause of osteoporosis. The imbalance can be the result of the action of various molecules produced by one bone cell that acts on other bone cells and influence cell activity. The understanding of the effect of these molecules on bone can help identify new targets and therapeutics to prevent and treat bone disorders. In this article, we have focused on molecules that are produced by osteoblasts, osteocytes, and osteoclasts and their mechanism of action on these cells. We have also summarized the different pharmacological osteoporosis treatments that target different molecular aspects of these bone cells to minimize osteoporosis.

Network Pharmacology-Based Investigation on the Anti-Osteoporosis Mechanism of Astragaloside IV

Astragaloside IV is the main active ingredient of Astragalus membranaceus. Studies have found that it can promote the proliferation of osteoblasts and can antagonize the apoptosis of mouse osteoblasts induced by hydrogen peroxide, but its molecular mechanism for the treatment of osteoporosis is still not clear. First, we used 3 online platforms: CTD, PharmMapper and SwissTargetPrediction to retrieve the targets of Astragaloside IV, and collected osteoporosis-related targets. Next, we used Cytoscape 3.7.2 software to construct a visual network diagram of PPI and further screened the key genes of Astragaloside IV in the treatment of osteoporosis using cluster analysis. Finally, after the receptor and ligand were docked, the binding activity was assessed by docking score. We obtained 102 overlapping targets of Astragaloside IV and osteoporosis. According to the node degree value in the PPI network, the top 10 genes were PIK3CA, MAPK1, SRC, STAT3, VEGFA, HSP90AA1, RELA, AKT1, IGF1, EGFR, of which SRC, AKT1, PIK3CA could bind stably to Astragaloside IV. KEGG pathway enrichment results showed that Astragaloside IV treated osteoporosis through 10 main pathways, including PI3K-Akt signaling pathway, FoxO signaling pathway, MAPK pathway, and so on. The classification of these pathways belongs to signal transduction, immune system, development and regeneration and endocrine system. Astragaloside IV is significantly related to several pathways involved in osteoporosis, such as PI3K-Akt, FoxO signaling pathway and MAPK pathway. SRC, AKT1, and PIK3CA can bind stably with Astragaloside IV, and they may be hub genes for the treatment of osteoporosis.

Protective effect of rhaponticin on ovariectomy-induced osteoporosis in rats

Rhaponticin is a constituent isolated from numerous medicinal herbs. It has been reported earlier that rhaponticin possesses numerous biological effects like antiallergic, antidiabetic, hepatoprotective, and antithrombosis. The goal of this exploration was to scrutinize the therapeutic potential of rhaponticin on ovariectomy (OVX)-triggered osteoporosis in rats. Female Sprague Dawley rats were arbitrarily allocated to a sham-operated control group I, group II, which underwent OVX, and groups III and IV that underwent OVX were administered with rhaponticin (10 and 20 mg/kg). Rhaponticin was supplemented orally after 4 weeks of OVX and continued for about 16 weeks. Our findings exhibit that rhaponticin prevented the BMD diminution of femurs, induced by OVX, and protected the worsening of trabecular microarchitecture that are assisted through a noteworthy decline in skeletal remodeling as noticed through the diminished status of bone markers in a dose-dependent manner (10 and 20 mg/kg). OVX rats treated with rhaponticin efficiently enhanced body weight, lipid profiles, uterine index, bone turnover markers, inflammatory markers, and augmented the incidence of calcium in the OVX rats. Rhaponticin was established to restrain the functions of acid phosphatase, estradiol, and bone gla protein in OVX rats. Also, rhaponticin displayed some beneficial effects on histomorphometric and histopathological examination. It was observed that tabular area and thickness were reinstated in sham control and rhaponticin-treated OVX rats. We recognized that rhaponticin did not induce a damaging outcome on the skeletal organization of OVX rats. Moreover, we denote that rhaponticin can be an exceptional agent for the treatment and deal with associated bone diseases.

Liquiritigenin promotes osteogenic differentiation and prevents bone loss via inducing auto-lysosomal degradation and inhibiting apoptosis

Osteoporosis (OP) is a debilitating skeletal abnormality involving bone remodeling and bone cell homeostasis characterized by decreased bone strength and high fracture risk. A novel therapeutic intervention for OP by manipulating cellular autophagy-apoptosis processes to promote skeletal homeostasis is presented. Protective effects of the naturally occurring plant extract Liquiritigenin (LG) were demonstrated in an ovariectomy (OVX)-OP mouse model and preosteoblast MC3T3-E1 cells. Micro-CT and histological staining assessments of skeletal phenotype were applied alongside detection of autophagy activity in osteocytes and MC3T3-E1 cells by transmission electron microscopy (TEM). The effects of LG on chloroquine (CQ)- and the apoptosis-inducing TS-treated osteogenic differentiations and status of lysosomes within MC3T3-E1 cells were analyzed by Neutral red, Alizarin red S and alkaline phosphatase (ALP) staining and Western blot assays. Treatment with LG prevented bone loss, increased osteogenic differentiation in vivo and in vitro, and inhibited osteoclast formation to some extent. TEM analyses revealed that LG can improve auto-lysosomal degradation within osteocytes from OVX mice and MC3T3-E1 cells. The abnormal status of lysosomes associated with CQ and TS treatments was notably alleviated by LG which also reduced levels of apoptosis-induced inhibition of osteogenic differentiation and averted abnormal osteogenic differentiation as a consequence of a blockage in autolysosome degradation. Overall, LG stimulates bone growth in OVX mice through increased osteogenic differentiation and regulation of autophagy-apoptosis mechanisms, presenting an auspicious natural therapy for OP.

A functional motif of long noncoding RNA Nron against osteoporosis

Long noncoding RNAs are widely implicated in diverse disease processes. Nonetheless, their regulatory roles in bone resorption are undefined. Here, we identify lncRNA Nron as a critical suppressor of bone resorption. We demonstrate that osteoclastic Nron knockout mice exhibit an osteopenia phenotype with elevated bone resorption activity. Conversely, osteoclastic Nron transgenic mice exhibit lower bone resorption and higher bone mass. Furthermore, the pharmacological overexpression of Nron inhibits bone resorption, while caused apparent side effects in mice. To minimize the side effects, we further identify a functional motif of Nron. The delivery of Nron functional motif to osteoclasts effectively reverses bone loss without obvious side effects. Mechanistically, the functional motif of Nron interacts with E3 ubiquitin ligase CUL4B to regulate ERα stability. These results indicate that Nron is a key bone resorption suppressor, and the lncRNA functional motif could potentially be utilized to treat diseases with less risk of side effects.

LncRNAs are implicated in the pathogenesis of a number of diseases. Here, the authors show that the lncRNA Nron suppresses bone resorption, and show that delivery of a functional motif of Nron increases bone mass in mouse models of osteoporosis.

Acanthopanax senticosus aqueous extract ameliorates ovariectomy-induced bone loss in middle-aged mice by inhibiting the receptor activator of nuclear factor-κB ligand-induced osteoclastogenesis

Acanthopanax senticosus (Ciwujia) has broad-spectrum pharmacological activities, including osteoprotective effects. However, the mechanisms underlying these effects remain unclear. We investigated whether Acanthopanax senticosus aqueous extract (ASAE) ameliorates ovariectomy-induced bone loss in middle-aged mice through inhibition of osteoclastogenesis. In vitro, ASAE significantly suppressed the receptor activator of nuclear factor-κB ligand (RANKL)-stimulated osteoclast differentiation and formation of F-actin rings by downregulating the expression of the nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), c-Fos, and osteoclastogenesis-related marker genes and proteins, including c-Src, tartrate-resistant acid phosphatase (TRAP), cathepsin K, β3-integrin, and matrix metallopeptidase-9 (MMP-9). This was achieved by inhibiting RANK signaling pathways, including p65, c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38 in osteoclast precursors. In vivo, ASAE markedly ameliorated bone loss in ovariectomized (OVX) middle-aged mice. ASAE significantly inhibited the serum levels of tartrate-resistant acid phosphatase 5b (TRACP-5b) and RANKL, whereas it increased those of osteocalcin, procollagen 1 N-terminal peptide (P1NP), and osteoprotegerin in OVX mice. ASAE significantly inhibited the OVX-induced expression of osteoclast-specific proteins and genes in the femur. In conclusion, ASAE prevents ovariectomy-induced bone loss in middle-aged mice by inhibiting RANKL-induced osteoclastogenesis through suppression of RANK signaling pathways and could be potentially used in mediated treatment of osteoclast-related diseases (e.g., osteoporosis).

Middle East experience from the Asia And Latin America Fracture Observational Study (ALAFOS): Baseline characteristics of postmenopausal women with osteoporosis using teriparatide

OBJECTIVE

We aimed to describe the baseline clinical characteristics and fracture history of patients taking teriparatide in routine clinical practice in the Middle East (ME) subregional cohort of the Asia and Latin America Fracture Observational Study (ALAFOS).

METHODS

Herein, we report baseline clinical characteristics of patients who were prescribed teriparatide (20 µg/day, subcutaneous injection) in four participant ME countries (Saudi Arabia, United Arab Emirates, Kuwait, and Lebanon).

RESULTS

The ME cohort included 707 patients mean (SD) age 69.3 (11.6) years. Mean (SD) bone mineral density (BMD) T-scores at baseline were -3.13 (1.28) for lumbar spine, -2.88 (0.94) for total hip, and -2.65 (1.02) for femoral neck. Osteoporotic fractures after age 40 years were reported in 45.8% (vertebral fracture 14.4%, hip fracture 18.4%) and comorbidities in 57.4% of patients. Before starting teriparatide, 19.9% of patients took other osteoporosis medications. The median (Q1; Q3) EuroQoL 5-Dimension 5-Level visual analog scale score for perceived overall health status was 70 (50; 80). Mean (SD) worst back pain in the previous 24 hours was 4.0 (3.2) using a 10-point numeric rating scale.

CONCLUSION

This analysis indicated that in ME countries, teriparatide is usually prescribed to patients with low BMD and high comorbidities, with prior fractures.

In Silico Network Analysis of Ingredients of Cornus officinalis in Osteoporosis

BACKGROUND Cornus officinalis (CO), also known as 'Shanzhuyu', is one of the most common traditional Chinese herbs used against osteoporosis. Although previous studies have found that CO has beneficial effects in alleviating osteoporosis, its mechanisms remain unclear. MATERIAL AND METHODS In this study, we applied system bioinformatic approaches to investigate the possible therapeutic mechanisms of CO against osteoporosis. We collected the active ingredients of CO and their targets from the TCMSP, BATMAN-TCM, and ETCM databases. Next, we obtained the osteoporosis targets from differentially expressed mRNAs from the Gene Expression Omnibus (GEO) gene series (GSE35958). Next, the shared genes of the CO pharmacological targets and osteoporosis-related targets were selected to construct the protein-protein interaction network, based on the results from the STRING database. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were carried out by using the clusterProfiler package in R software. RESULTS In all, there were 58 unique CO compounds and 518 therapeutic targets. Based on the GO and KEGG enrichment results of 98 common genes, we selected the top 25 terms, based on the terms' P values. We found that the anti-osteoporotic effect of CO may mostly involve the regulation of calcium metabolism and reactive oxygen species, and the estrogen signaling pathway and osteoclast differentiation pathway. CONCLUSIONS We found the possible mechanisms of CO in treating osteoporosis may be based on multiple targets and pathways. We also provided a theoretical basis and promising direction for investigating the exact anti-osteoporotic mechanisms of CO.

Investigating the role of osteoprotegerin gene polymorphic variants in osteoporosis

In recent genome-wide association studies (GWAS), several polymorphic loci of the osteoprotegerin (OPG) gene were significantly associated with bone mineral density (BMD) and fractures in men over 50 years of age and postmenopausal women. The objective of our study was to search for associations of rs3102735, rs3134069, rs2073617, rs2073618, rs3102734 and rs7844539 of the OPG gene with the risk of osteoporotic fractures and the level of BMD in individual and comorbid conditions in men and women from the Volga-Ural region of Russia. Material and Methods — 828 women and 496 men of various ethnic groups (Russians, Turks) were examined using two-energy x-ray absorptiometry (DEXA) in the femoral neck and lumbar spine. 1324 deoxyribonucleic acid (DNA) samples were genotyped using a fluorescent endpoint genotyping system, after that we searched for associations of these polymorphic loci with fractures and low BMD levels of various localizations. As a result, there was a significant association of rs3134069 and rs3102734 with fractures in general and in the peripheral parts of the skeleton, as well as rs7844539 and rs3102734 in women and rs2073618 in men with low BMD. Another significant association of rs3102734 and rs2073618 with low bone mineral density in the femoral neck was found in both genders. Conclusion — Polymorphic variants rs3134069, rs3102734, rs7844539 and rs3102734 are potential markers of the risk of osteoporetic fractures and the formation of low BMD in men and women from the Volga-Ural region of Russia.

QingYan formula extracts protect against postmenopausal osteoporosis in ovariectomized rat model via active ER-dependent MEK/ERK and PI3K/Akt signal pathways

ETHNOPHARMACOLOGICAL RELEVANCE

QingYan Formula has been traditionally used to tonify kidney and benefit essence, and QingYan Formula 70% ethanol extracts (QYFE) showed estrogen-like effect on reproductive system in our previous studies. However, there were no reports of QYFE on bone.

AIM OF THE STUDY

This study offered preliminary insight of QYFE into the pharmacodynamics and mechanism of anti-bone osteoporosis in ovariectomized rats.

MATERIALS AND METHODS

OVX rats were orally administrated QYFE or estradiol valerate (EV) for 12 weeks. We investigated the pharmacodynamic effects of QYFE on anti-bone loss in OVX rats, and also investigated the role of QYFE in promoting osteogenesis and inhibiting osteoclast differentiation.

RESULTS

QYFE administration significantly reduced the degree of high bone turnover, dose-dependently repaired the damaged microstructure of trabecular and cortical bone by Hematoxylin-Eosin (HE) staining and micro-computed tomography (micro-CT), and reduced the number of femur osteoclasts by TRAP staining. QYFE enhanced the proliferation and activity of alkaline phosphatase (ALP), the phosphorylation levels of extracellular regulated kinase (ERK) and Akt in MG-63 cells, which was inhibited by ICI 182 780. Moreover, in RAW264.7 cells, QYFE inhibited osteoclasts differentiation, reduced the number of osteoclasts, decreased the activity of TRAP enzyme during formation, down-regulated the protein expression of p-ERK inhibited by ICI 182 780 and p-Akt not inhibited by ICI 182 780.

CONCLUSION

This experiment demonstrated that QYFE had a definite anti-bone loss effect and had potential effect on postmenopausal osteoporosis. The molecular mechanism was related to the activation of estrogen receptor (ER)-dependent mitogen-activated protein kinase kinase (MEK)/ERK and phosphoinositide 3-kinase (PI3K)/Akt signal pathways in osteoblast, down-regulation protein expressions of ER-dependent p-ERK and ER-independent p-Akt in osteoclast.

An oligopeptide/aptamer-conjugated dendrimer-based nanocarrier for dual-targeting delivery to bone

Bone targeting is one of the most potentially valuable therapeutic methods for medically treating bone diseases, such as osteoarthritis, osteoporosis, nonunion bone defects, bone cancer, and myeloma-related bone disease, but its efficacy remains a challenge due to unfavorable bone biodistribution, off-target effects, and the lack of cell specificity. To address these problems, we synthesized a new dual-targeting nanocarrier for delivery to bone by covalently modifying the G4.0 PAMAM dendrimer with the C11 peptide and the CH6 aptamer (CH6-PAMAM-C11). The molecular structure was confirmed using ¹H-NMR and FT-IR spectroscopy. CLSM results showed that the novel nanocarrier could successfully accumulate in the targeted cells, mineralized areas and tissues. DLS and TEM demonstrated that CH6-PAMAM-C11 was approximately 40-50 nm in diameter. In vitro targeting experiments confirmed that the C11 ligand had a high affinity for HAP, while the CH6 aptamer had a high affinity for osteoblasts. The in vivo biodistribution analysis showed that CH6-PAMAM-C11 could rapidly accumulate in bone within 4 h and 12 h and then deliver drugs to sites of osteoblast activity. The components of CH6-PAMAM-C11 were well excreted via the kidneys. The accumulation of many more CH6-PAMAM-C11 dual-targeting nanocarriers than single-targeting nanocarriers was observed in the periosteal layer of the rat skull, along with aggregation at sites of osteoblast activity. All of these results indicate that CH6-PAMAM-C11 may be a promising nanocarrier for the delivery of drugs to bone, particularly for the treatment of osteoporosis, and our research strategy may serve as a reference for research in targeted drug, small molecule drug and nucleic acid delivery.

Treatment of osteoporosis with a modified zeolite shows beneficial effects in an osteoporotic rat model and a human clinical trial

The severity of osteoporosis in humans manifests in its high incidence and by its complications that diminish quality of life. A societal consequence of osteoporosis is the substantial burden that it inflicts upon patients and their families. Several bone-modifying drugs have been prescribed to patients with osteoporosis. However, evidence for their anti-fracture efficacy remains inconclusive. To the contrary, long-term use of anti-osteoporotic drugs such as bisphosphonates and Denosumab, an RANKL inhibitor, have resulted in adverse events. We now present an alternative and adjuvant approach for treatment of osteoporosis. The data derive from in vivo studies in an ovariectomized rat model and from a randomized double blind, placebo-controlled human clinical study. Both studies involved treatment with Panaceo Micro Activation (PMA)-zeolite-clinoptilolite, a defined cation exchange clinoptilolite, which clearly improved all bone histomorphometric parameters examined from ovariectomized animals, indicative for increased bone formation. Moreover, intervention with PMA-zeolite-clinoptilolite for one year proved safe in humans. Furthermore, patients treated with PMA-zeolite-clinoptilolite showed an increase in bone mineral density, an elevated level of markers indicative of bone formation, a significant reduction in pain, and significantly improved quality of life compared with patients in the control (placebo) group. These encouraging positive effects of PMA-zeolite-clinoptilolite on bone integrity and on osteoporosis warrant further evaluation of treatment with PMA-zeolite-clinoptilolite as a new alternative adjuvant therapy for osteoporosis.

Is an anodizing coating associated to the photobiomodulation able to optimize bone healing in ovariectomized animal model?

This in vivo study investigated whether the bioactivity of anodizing coating, produced by plasma electrolytic oxidation (PEO), on mini-plate in femur fracture could be improved with the association of photobiomodulation (PBM) therapy. From the 20 ovariectomized Wistar female rats, 8 were used for model characterization, and the remaining 12 were divided into four groups according to the use of PBM therapy by diode laser (808 nm; power: 100 mW; energy: 6.0 J; energy density: 212 J/cm²; power density: 3.5 W/cm²) and the type of mini-plate surface (commercially pure titanium mini-plate -cpTi- and PEO-treated mini-plate) as follow: cpTi; PEO; cpTi/PBM; and PEO/PBM. After 60 days of surgery, fracture healing underwent microstructural, bone turnover, histometric, and histologic adjacent muscle analysis. Animals of groups with PEO and PBM showed greater fracture healing than cpTi control group under histometric and microstructural analysis (P < 0.05); however, bone turnover was just improved in PBM's groups (P < 0.05). there was no difference between cpTi and PEO without PBM (P > 0.05). Adjacent muscle analysis showed no metallic particles or muscle alterations in all groups. PEO and PBM are effective strategies for bone repair in fractures, however their association does not provide additional advantages.

Osteoporosis: Current and Emerging Therapies Targeted to Immunological Checkpoints

Osteoporosis is a skeletal pathology characterized by compromised bone strength leading to increased risk of fracture, mainly the spine and hip fractures. Osteoporosis affects more than 200 million people worldwide and because of the skeletal fractures it causes, represents a major cause of morbidity, disability and mortality in older people. Recently, the new discoveries of osteoimmunology have clarified many of the pathogenetic mechanisms of osteoporosis, helping to identify new immunological targets for its treatment opening the way for new and effective therapies with biological drugs. Currently, there are basically two monoclonal antibodies for osteoporosis therapy: denosumab and romosozumab. Here, we focus on the modern approach to the osteoporosis management and in particular, on current and developing biologic drugs targeted to new immunological checkpoints, in the landscape of osteoimmunology.

Molecular Signaling Pathways and Essential Metabolic Elements in Bone Remodeling: An Implication of Therapeutic Targets for Bone Diseases

Bone is one of the dynamic tissues in the human body that undergoes continuous remodelling through subsequent actions of bone cells, osteoclasts, and osteoblasts. Several signal transduction pathways are involved in the transition of mesenchymal stem cells into osteoblasts. These primarily include Runx2, ATF4, Wnt signaling and sympathetic signalling. The differentiation of osteoclasts is controlled by M-CSF, RANKL, and costimulatory signalling. It is well known that bone remodelling is regulated through receptor activator of nuclear factor-kappa B ligand followed by binding to RANK, which eventually induces the differentiation of osteoclasts. The resorbing osteoclasts secrete TRAP, cathepsin K, MMP-9 and gelatinase to digest the proteinaceous matrix of type I collagen and form a saucer-shaped lacuna along with resorption tunnels in the trabecular bone. Osteoblasts secrete a soluble decoy receptor, osteoprotegerin that prevents the binding of RANK/RANKL and thus moderating osteoclastogenesis. Moreover, bone homeostasis is also regulated by several growth factors like, cytokines, calciotropic hormones, parathyroid hormone and sex steroids. The current review presents a correlation of the probable molecular targets underlying the regulation of bone mass and the role of essential metabolic elements in bone remodelling. Targeting these signaling pathways may help to design newer therapies for treating bone diseases.

Role of LncRNAs and CircRNAs in Bone Metabolism and Osteoporosis

Bone is a mechanosensitive organ that provides strength and support. Many bone cells, various pathways, and signaling molecules coordinate bone metabolism and also determine the course of bone diseases, such as osteoporosis, osteonecrosis, osteopenia, etc. Osteoporosis is caused by increased bone resorption and reduced bone formation due to the changes in the level of different proteins and RNAs in osteoclast or/and osteoblasts. The available therapeutic interventions can significantly reduce bone resorption or enhance bone formation, but their prolonged use has deleterious side effects. Therefore, the use of non-coding RNAs as therapeutics has emerged as an interesting field of research. Despite advancements in the molecular field, not much is known about the role of long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in bone homeostasis and osteoporosis. Therefore, in this article, we summarize the role of lncRNAs and circRNAs in different bone cells and osteoporosis so that it might help in the development of osteoporotic therapeutics.

Beneficial effect of 2'-acetylacteoside on ovariectomized mice via modulating the function of bone resorption

2'-Acetylacteoside-(2'-AA), a bioactive constituent isolated from Cistanche deserticola, has been proven to possess a variety of important pharmacological effects, thus brought an increased amount of scientists' attention. As the extract of C. deserticola exhibited significant anti-osteoporotic bioactivity in our previous study, we proposed that 2'-AA maybe one of the responsibilities. As a result, 2'-AA (10, 20 and 40 mg/kg body weight/day) exhibited significant anti-osteoporotic effects on ovariectomized (OVX) mice after 12 weeks of oral administration, confirmed by the increased bone mineral density, enhanced bone strength and improved trabecular bone micro-architecture including bone mineral content, tissue mineral content, trabecular number, and trabecular separation of OVX mice. Moreover, the properties of bone resorption markers including cathepsin K, TRAP and deoxypyridinoline were significantly suppressed, whereas the activities of bone formation index like ALP and BGP as well as the weights of the body, uterus, and vagina were seemingly not influenced by 2'-AA intervention. Mechanistically, the above therapeutic effect of 2'-AA on bone resorption of OVX mice operated maybe mainly through RANKL/RANK/TRAF6-mediated NF-κB/NFATc1 pathway, which was confirmed by the down-regulated expressions of RANK, TRAF6, IκB kinase β, NF-κB and NFATc1. Summarily, 2'-AA exhibited significant anti-osteoporotic activity and may be regarded as a promising anti-osteoporotic candidate for future clinical trial.

Deciphering the Underlying Mechanism of Eucommiae Cortex against Osteoporotic Fracture by Network Pharmacology

Background

Du Zhong (DZ), or Eucommiae Cortex, a traditional Chinese herbal medicine, has been used to treat osteoporosis. Although it has been reported that DZ can improve bone mass in ovariectomized rats, its pharmacological mechanisms in treating osteoporotic fractures (OPF) remain unclear.

Methods

In this study, we used a network pharmacological manner to explore its potential complicated mechanism in treating OPF. We obtained DZ compounds from TCMSP and BATMAN-TCM databases and collected potential targets of these compounds through target fishing based on TCMSP and BATMAN-TCM databases. Next, we collected the OPF targets by using CTD, GeneCards, OMIM, HPO, and GenCLiP 3 databases. And then the overlapping genes between DZ potential targets and OPF targets were used to build up the protein-protein interaction (PPI) network and to analyze their interactions and find out the big hub genes in this network. Subsequently, clusterProfiler package in R language was utilized to conduct the enrichment of Gene Ontology biological process and KEGG pathways.

Results

There were totally 93 active compounds and 916 related targets in DZ. After the enrichment analysis, we collected top 25 cellular biological processes and top 25 pathways based on the adjusted P value and found that the DZ anti-OPF effect was mainly associated with the regulation of ROS and inflammatory response. Furthermore, 64 hub genes in PPI network, such as MAPK1 (degree = 41), SRC (degree = 39), PIK3R1 (degree = 36), VEGFA (degree = 31), TP53 (degree = 29), EGFR (degree = 29), JUN (degree = 29), AGT (degree = 29), MAPK1, SRC, PIK3R1, VEGFA, and TP53, were considered as potential therapeutic targets, implying the underlying mechanisms of DZ acting on OPF.

Conclusion

We investigated the possible therapeutic mechanisms of DZ from a systemic perspective. These key targets and pathways provided promising directions for the future research to reveal the exact regulating mechanisms of DZ in treating OPF.