Tartrate-resistant acid phosphatase 5b: a novel serum marker of bone resorption

Intersecting Paths: Unraveling the Complex Journey of Cancer to Bone Metastasis

The phenomenon of bone metastases presents a significant challenge within the context of advanced cancer treatments, particularly pertaining to breast, prostate, and lung cancers. These metastatic occurrences stem from the dissemination of cancerous cells into the bone, thereby interrupting the equilibrium between osteoblasts and osteoclasts. Such disruption results in skeletal complications, adversely affecting patient morbidity and quality of life. This review discusses the intricate interplay between cancer cells and the bone microenvironment, positing the bone not merely as a passive recipient of metastatic cells but as an active contributor to cancer progression through its distinctive biochemical and cellular makeup. A thorough examination of bone structure and the dynamics of bone remodeling is undertaken, elucidating how metastatic cancer cells exploit these processes. This review explores the genetic and molecular pathways that underpin the onset and development of bone metastases. Particular emphasis is placed on the roles of cytokines and growth factors in facilitating osteoclastogenesis and influencing osteoblast activity. Additionally, this paper offers a meticulous critique of current diagnostic methodologies, ranging from conventional radiography to advanced molecular imaging techniques, and discusses the implications of a nuanced understanding of bone metastasis biology for therapeutic intervention. This includes the development of targeted therapies and strategies for managing bone pain and other skeletal-related events. Moreover, this review underscores the imperative of ongoing research efforts aimed at identifying novel therapeutic targets and refining management approaches for bone metastases. It advocates for a multidisciplinary strategy that integrates advancements in medical oncology and radiology with insights derived from molecular biology and genetics, to enhance prognostic outcomes and the quality of life for patients afflicted by this debilitating condition. In summary, bone metastases constitute a complex issue that demands a comprehensive and informed approach to treatment. This article contributes to the ongoing discourse by consolidating existing knowledge and identifying avenues for future investigation, with the overarching objective of ameliorating patient care in the domain of oncology.

Risk factors for nonresponse to 2 years of denosumab administration in patients with osteoporosis: A retrospective single-center cohorts study

Background and Aims

To investigate the factors associated with changes in bone mineral density (BMD) and the incidence of fractures in osteoporotic patients treated with denosumab.

Methods

This retrospective study included 162 osteoporotic patients treated with denosumab for 24 months between 2013 and 2019. Patients were divided according to the changes in BMD as nonresponders (NL group: <3% increase in lumbar spine BMD [LBMD], NH group: <0% increase in femoral neck BMD [FNBMD]) or responders (RL group: ≥3% increase in LBMD, RH group: ≥0% increase in FNBMD).

Results

The respective changes in the LBMD and FNBMD after 24 months of denosumab treatment were 9.3% (95% confidence interval [CI]: 8.1-10.6) and 3.3% (95% CI: 2.1-4.5). Twenty-eight (17.3%) patients were in the NL group, and 134 (82.7%) were in the RL group. A history of bisphosphonate treatment was a risk factor for being in the NL group (odds ratio [OR]: 3.84, 95% CI: 1.38-10.71, p = 0.007; adjusted OR: 3.21, 95% CI: 1.01-10.19, p = 0.048). Although the NH (n = 48; 30.8%) and RH (n = 108; 69.2%) groups had similar baseline characteristics, the NH group had a significantly higher baseline FNBMD than the RH group (p = 0.003). The change in FNBMD was negatively associated with the FNBMD at baseline (r = -0.34, p < 0.001). No new osteoporotic fractures occurred in either group during follow-up.

Conclusion

In osteoporotic patients receiving denosumab treatment, a history of bisphosphonate treatment was a risk factor for a lack of increase in LBMD, and a higher FNBMD at baseline was negatively associated with the change in FNBMD.

Bone metabolism and inflammatory biomarkers in radiographic and non-radiographic axial spondyloarthritis patients: a comprehensive evaluation

Introduction

Axial spondyloarthritis (axSpA) is a heterogeneous disease that can be represented by radiographic axSpA (r-axSpA) and non-radiographic axSpA (nr-axSpA). This study aimed to evaluate the relationship between the markers of inflammation and bone turnover in r-axSpA patients and nr-axSpA patients.

Methods

A cross-sectional study included 29 r-axSpA patients, 10 nr-axSpA patients, and 20 controls matched for age and sex. Plasma markers related to bone remodeling such as human procollagen type 1 N-terminal propeptide (P1NP), sclerostin, tartrate-resistant acid phosphatase 5b (TRACP5b), receptor activator of nuclear factor kappa B ligand (RANKL), and osteoprotegerin (OPG) were measured by an ELISA kit. A panel of 92 inflammatory molecules was analyzed by proximity extension assay.

Results

R-axSpA patients had decreased plasma levels of P1NP, a marker of bone formation, compared to controls. In addition, r-axSpA patients exhibited decreased plasma levels of sclerostin, an anti-anabolic bone hormone, which would not explain the co-existence of decreased plasma P1NP concentration; however, sclerostin levels could also be influenced by inflammatory processes. Plasma markers of osteoclast activity were similar in all groups. Regarding inflammation-related molecules, nr-axSpA patients showed increased levels of serum interleukin 13 (IL13) as compared with both r-axSpA patients and controls, which may participate in the prevention of inflammation. On the other hand, r-axSpA patients had higher levels of pro-inflammatory molecules compared to controls (i.e., IL6, Oncostatin M, and TNF receptor superfamily member 9). Correlation analysis showed that sclerostin was inversely associated with IL6 and Oncostatin M among others.

Conclusion

Altogether, different inflammatory profiles may play a role in the development of the skeletal features in axSpA patients particularly related to decreased bone formation. The relationship between sclerostin and inflammation and the protective actions of IL13 could be of relevance in the axSpA pathology, which is a topic for further investigation.

Agomelatine alleviates steroid-induced osteoporosis by targeting SIRT1/RANKL/FOXO1/OPG signalling in rats

One of the major contributors to secondary osteoporosis is long-term glucocorticoid usage. Clinically used antidepressant agomelatine also has anti-inflammatory properties. Our research aimed to inspect the probable defensive effect of agomelatine against steroid-promoted osteoporosis. There were four groups of rats; group I had saline as a negative control; rats of group II had dexamethasone (0.6 mg/kg, s.c.), twice weekly for 12 weeks; rats of group III had agomelatine (40 mg/kg/day, orally), as a positive control, daily for 12 weeks; and rats of group IV had dexamethasone + agomelatine in the same previous doses combined for 12 weeks. Finally, biochemical as well as histopathological changes were evaluated and dexamethasone treatment caused osteoporosis, as evidenced by discontinuous thin cancellous bone trabeculae, minor fissures and fractures, irregular eroded endosteal surface with elevated alkaline phosphate, tartarate resistant acid phosphate (TRACP) and osteocalcin levels. Osteoprotegerin (OPG), calcium, and phosphorus levels decreased with disturbed receptor activator of nuclear factor κ B ligand (RANKL), forkhead box O1 (FOXO1), and silent information regulator 1 (SIRT1) protein expression. However, treatment with agomelatine restored the normal levels of biochemical parameters to a great extent, supported by SIRT activation with an improvement in histopathological changes. Here, we concluded that agomelatine ameliorates steroid-induced osteoporosis through a SIRT1/RANKL/FOXO1/OPG-dependent pathway.

Changes of bone turnover markers and testosterone in Japanese male endurance runners: a pilot study

INTRODUCTION

The bone metabolism of male endurance runners during a competitive season has been little studied. Furthermore, Japanese runners have a special competitive season. This study aimed to investigate the change of bone turnover markers (BTMs) and other hormones in Japanese male endurance runners.

MATERIALS AND METHODS

We investigated biochemical markers, bone formation and resorption markers and sex hormones, body composition using dual-energy X-ray absorptiometry (DXA), and training volume during a competitive season. 11 (age: 24.0 ± 4.3 years) Japanese male endurance runners were analyzed in this study. They participated in all measurements three times a year: the baseline (BL), the post-track period (PT), and the road race period (RR).

RESULTS

Fat mass (FM) and percentage of body fat (% body fat) at RR (p = 0.009, p = 0.009) were lower than at BL. Specific bone alkaline phosphatase (BAP) decreased at PT (p = 0.004) and RR (p = 0.004) compared with BL. However, the bone resorption marker did not change. Free testosterone at PT (p = 0.032) was lower than BL. There was no correlation with blood variables and body composition or training volume.

CONCLUSION

BAP and testosterone in Japanese male endurance runners decreased during the competitive season. However, there was no correlation between blood variables and training volume.

Biofabrication of anin-vitrobone model for Gaucher disease

Gaucher disease (GD), the most prevalent lysosomal disorder, is caused byGBA1gene mutations, leading to deficiency of glucocerebrosidase, and accumulation of glycosphingolipids in cells of the mononuclear phagocyte system. While skeletal diseases are the leading cause of morbidity and reduced quality of life in GD, the pathophysiology of bone involvement is not yet fully understood, partly due to lack of relevant human model systems. In this work, we present the first 3D human model of GD using aspiration-assisted freeform bioprinting, which enables a platform tool with a potential for decoding the cellular basis of the developmental bone abnormalities in GD. In this regard, human bone marrow-derived mesenchymal stem cells (obtained commercially) and peripheral blood mononuclear cells derived from a cohort of GD patients, at different severities, were co-cultured to form spheroids and differentiated into osteoblast and osteoclast lineages, respectively. Co-differentiated spheroids were then 3D bioprinted into rectangular tissue patches as a bone tissue model for GD. The results revealed positive alkaline phosphatase (ALP) and tartrate-resistant ALP activities, with multi-nucleated cells demonstrating the efficacy of the model, corroborating with gene expression studies. There were no significant changes in differentiation to osteogenic cells but pronounced morphological deformities in spheroid formation, more evident in the 'severe' cohort, were observed. Overall, the presented GD model has the potential to be adapted to personalized medicine not only for understanding the GD pathophysiology but also for personalized drug screening and development.

Optimization of an α-aminonaphthylmethylphosphonic acid inhibitor of purple acid phosphatase using rational structure-based design approaches

Purple acid phosphatases (PAPs) are ubiquitous binuclear metallohydrolases that have been isolated from various animals, plants and some types of fungi. In humans and mice, elevated PAP activity in osteoclasts is associated with osteoporosis, making human PAP an attractive target for the development of anti-osteoporotic drugs. Based on previous studies focusing on phosphonate scaffolds, as well as a new crystal structure of a PAP in complex with a derivative of a previously synthesized α-aminonaphthylmethylphosphonic acid, phosphonates 24-40 were designed as new PAP inhibitor candidates. Subsequent docking studies predicted that all of these compounds are likely to interact strongly with the active site of human PAP and most are likely to interact strongly with the active site of pig PAP. The seventeen candidates were synthesized with good yields and nine of them (26-28, 30, 33-36 and 38) inhibit in the sub-micromolar to nanomolar range against pig PAP, with 28 and 35 being the most potent mammalian PAP inhibitors reported with K_i values of 168 nM and 186 nM, respectively. This study thus paves the way for the next stage of drug development for phosphonate inhibitors of PAPs as anti-osteoporotic agents.

Pulmonary osteoclast-like cells in silica induced pulmonary fibrosis

The pathophysiology of silicosis is poorly understood, limiting development of therapies for those who have been exposed to the respirable particle. We explored the mechanisms of silica-induced pulmonary fibrosis in a mouse model using multiple modalities including whole-lung single-nucleus RNA sequencing. These analyses revealed that in addition to pulmonary inflammation and fibrosis, intratracheal silica challenge induced osteoclast-like differentiation of alveolar macrophages and recruited monocytes, driven by induction of the osteoclastogenic cytokine, receptor activator of nuclear factor-κB ligand (RANKL) in pulmonary lymphocytes and alveolar type II cells. Furthermore, anti-RANKL monoclonal antibody treatment suppressed silica-induced osteoclast-like differentiation in the lung and attenuated silica-induced pulmonary fibrosis. We conclude that silica induces osteoclast-like differentiation of distinct recruited and tissue resident monocyte populations, leading to progressive lung injury, likely due to sustained elaboration of bone resorbing proteases and hydrochloric acid. Interrupting osteoclast-like differentiation may therefore constitute a promising avenue for moderating lung damage in silicosis.

Practical Considerations for the Clinical Application of Bone Turnover Markers in Osteoporosis

Bone turnover markers (BTMs) are released during the bone remodelling cycle and are measurable in blood or urine, reflecting bone remodelling rate. They have been useful in elucidating the pharmacodynamics and effectiveness of osteoporosis medication in clinical trials and are increasingly used in routine clinical management of osteoporosis, especially for monitoring therapy, in addition to their use in other metabolic bone disease such as Paget's disease of bone and osteomalacia. Serum β isomerised C-terminal telopeptide of type I collagen and pro-collagen I N-terminal propeptide have been designated as reference BTMs for use in osteoporosis. In addition, bone-specific isoenzyme of alkaline phosphatase (B-ALP) secreted by osteoblasts and tartrate-resistant acid phosphatase 5b (TRACP-5b) secreted by osteoclasts are also found to be specific markers of bone formation and resorption, respectively. The concentrations of the latter enzymes in blood measured by immunoassay provide reliable measures of bone turnover even in the presence of renal failure. B-ALP is recommended for use in the assessment of renal bone disease of chronic kidney disease, and TRACP-5b shows promise as a marker of bone resorption in that condition. BTMs in blood do not suffer from biological variation to the same extent as the older BTMs that were measured in urine. Appropriate patient preparation and sample handling are important in obtaining accurate measures of BTMs for clinical use. Reference change values and treatment targets have been determined for the reference BTMs for their use in monitoring osteoporosis treatment. Further ongoing studies will enhance their clinical applications.

Diagnostic and prognostic significance of tartrate-resistant acid phosphatase type 5b in newly diagnosed prostate cancer with bone metastasis: A real-world multi-institutional study

OBJECTIVES

Approximately, 90% of men with advanced prostate cancer will develop bone metastasis. However, there have been few reports about noninvasive biomarker to detect and predict clinical outcome of bone metastasis (BM) in prostate cancer patients.

METHODS

We examined 1127 patients who underwent prostate biopsy from August 2012 to June 2017. We also investigated bone turnover markers such as bone-specific alkaline phosphatase, type I collagen cross-linked N-terminal telopeptide, C-terminal pyridinoline cross-linked telopeptide of type I collagen, and tartrate-resistant acid phosphatase type 5b (TRACP 5b).

RESULTS

A total of 282 patients were diagnosed as prostate cancer with complete clinical data, and 34 patients with bone metastasis. Multivariate analysis revealed C-terminal pyridinoline cross-linked telopeptide of type I collagen, tartrate-resistant acid phosphatase type 5b, and prostate-specific antigen (PSA) were independent biomarkers in detection of BM (p < 0.05, respectively). Furthermore, we developed predictive model formula based on tartrate-resistant acid phosphatase type 5b and PSA, for which the area under the curve was 0.95. In patients with bone metastasis, multivariate cox proportional hazards analysis revealed that this model was significantly associated with poor clinical outcome of cancer-specific survival (p < 0.05). In validation cohort with 137 patients, we also confirmed the utility of this model for diagnosis of BM (the area under the curve = 0.95).

CONCLUSIONS

Our developed formula of tartrate-resistant acid phosphatase type 5b in accordance with PSA may serve as the useful tool in diagnosis and prediction of clinical outcome for prostate cancer with bone metastasis.

Reduced Bone Mass and Increased Osteocyte Tartrate-Resistant Acid Phosphatase (TRAP) Activity, But Not Low Mineralized Matrix Around Osteocyte Lacunae, Are Restored After Recovery From Exogenous Hyperthyroidism in Male Mice

Hyperthyroidism causes secondary osteoporosis through favoring bone resorption over bone formation, leading to bone loss with elevated bone fragility. Osteocytes that reside within lacunae inside the mineralized bone matrix orchestrate the process of bone remodeling and can themselves actively resorb bone upon certain stimuli. Nevertheless, the interaction between thyroid hormones and osteocytes and the impact of hyperthyroidism on osteocyte cell function are still unknown. In a preliminary study, we analyzed bones from male C57BL/6 mice with drug-induced hyperthyroidism, which led to mild osteocytic osteolysis with 1.14-fold larger osteocyte lacunae and by 108.33% higher tartrate-resistant acid phosphatase (TRAP) activity in osteocytes of hyperthyroid mice compared to euthyroid mice. To test whether hyperthyroidism-induced bone changes are reversible, we rendered male mice hyperthyroid by adding levothyroxine into their drinking water for 4 weeks, followed by a weaning period of 4 weeks with access to normal drinking water. Hyperthyroid mice displayed cortical and trabecular bone loss due to high bone turnover, which recovered with weaning. Although canalicular number and osteocyte lacunar area were similar in euthyroid, hyperthyroid and weaned mice, the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL)-positive osteocytes was 100% lower in the weaning group compared to euthyroid mice and the osteocytic TRAP activity was eightfold higher in hyperthyroid animals. The latter, along with a 3.75% lower average mineralization around the osteocyte lacunae in trabecular bone, suggests osteocytic osteolysis activity that, however, did not result in significantly enlarged osteocyte lacunae. In conclusion, we show a recovery of bone microarchitecture and turnover after reversal of hyperthyroidism to a euthyroid state. In contrast, osteocytic osteolysis was initiated in hyperthyroidism, but its effects were not reversed after 4 weeks of weaning. Due to the vast number of osteocytes in bone, we speculate that even minor individual cell functions might contribute to altered bone quality and mineral homeostasis in the setting of hyperthyroidism-induced bone disease. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Exploration of the skeletal phenotype of the Col1a1 +/Mov13 mouse model for haploinsufficient osteogenesis imperfecta type 1

INTRODUCTION

Osteogenesis Imperfecta is a rare genetic connective tissue disorder, characterized by skeletal dysplasia and fragile bones. Currently only two mouse models have been reported for haploinsufficient (HI) mild Osteogenesis Imperfecta (OI); the Col1a1 ^+/Mov13 (Mov13) and the Col1a1 ^+/-365 mouse model. The Mov13 mice were created by random insertion of the Mouse Moloney leukemia virus in the first intron of the Col1a1 gene, preventing the initiation of transcription. Since the development of the Mov13 mice almost four decades ago and its basic phenotypic characterization in the 90s, there have not been many further studies. We aimed to extensively characterize the Mov13 mouse model in order to critically evaluate its possible use for preclinical studies of HI OI.

METHODS

Bone tissue from ten heterozygous Mov13 and ten wild-type littermates (WT) C57BL/6J mice (50% males per group) was analyzed at eight weeks of age with bone histomorphometry, micro computed tomography (microCT), 3-point bending, gene expression of different collagens, as well as serum markers of bone turnover.

RESULTS

The Mov13 mouse presented a lower bone strength and impaired material properties based on our results of 3-point bending and microCT analysis respectively. In contrast, no significant differences were found for all histomorphometric parameters. In addition, no significant differences in Col1a1 bone expression were present, but there was a significant lower P1NP concentration, a bone formation marker, measured in serum. Furthermore, bone tissue of Mov13 mice presented significantly higher expression of collagens (Col1a2, Col5a1 and Col5a2), and bone metabolism markers (Bglap, Fgf23, Smad7, Edn1 and Eln) compared to WT. Finally, we measured a significantly lower Col1a1 expression in heart and skin tissue and also determined a higher expression of other collagens in the heart tissue.

CONCLUSION

Although we did not detect a significant reduction in Col1a1 expression in the bone tissue, a change in bone structure and reduction in bone strength was noted. Regrettably, the variability of the bone phenotype and the appearance of severe lymphoma in adult Mov13 mice, does not favor their use for the testing of new long-term drug studies. As such, a new HI OI type 1 mouse model is urgently needed.

Lessons learned from long-term side effects after zoledronic acid infusion following denosumab treatment: a case report and review of the literature

BACKGROUND

Zoledronic acid is an intravenous, highly potent aminobisphosphonate for use in patients with primary or secondary osteoporosis. Zoledronic acid-induced prolonged side-effects are well known and quite common. However, severe side-effects can be a threat to life. We report a case of severe side-effects induced by zoledronic acid infusion, and its positive effect on long-term back pain.

CASE PRESENTATION

In 2012, a 62-year-old white native Finnish woman was operated on for an estrogen and progesterone receptor-positive breast cancer. After radiotherapy, an aromatase inhibitor (letrozole) was started. Nine months after the operation, the patient suffered a low-energy compression fracture of Th XII. She received denosumab to prevent fragility fractures and to improve bone mineral density. Letrozole was discontinued after 5.5 years, and the last denosumab injection was given after 7 years. Six months later, at the age of 71 years, the patient received a single intravenous zoledronic acid infusion. Suddenly, at 10 hours from the infusion, she complained of severe trismus, muscle twitching, spasms, and tingling, matching hypocalcemia and several other symptoms. Her serum 25-hydroxyvitamin D concentration was high (163 nmol/L), the concentration of serum calcium and calcium-ion was normal (2.32 mmol/L and 1.23 mmol/L, respectively). However, the neutrophil to lymphocyte ratio (NLR) was low (1.6). A complete recovery took 2 months. Zoledronic acid infusion also had a positive effect: for many years, the patient had suffered low back pain and strain, which came to an end after this single infusion.

CONCLUSION

It is important that the potential patients receive sufficient information about the possibility of side-effects following the administration of intravenous zoledronic acid. To ensure that a zoledronic acid infusion is given as safely as possible, the safety information should include that the patient should not be left without monitoring for a minimum 24 hours after the infusion. Being alone and experiencing serious side-effects may lead to acute cardiac problems. Furthermore, the chronic low back pain and strain that our patient suffered for many years has clearly reduced for 16 months after infusion, so far. We conclude that this is a positive effect of zoledronic acid.

Bone Turnover Markers: Basic Biology to Clinical Applications

Bone turnover markers (BTMs) are used widely, in both research and clinical practice. In the last 20 years, much experience has been gained in measurement and interpretation of these markers, which include commonly used bone formation markers bone alkaline phosphatase, osteocalcin, and procollagen I N-propeptide; and commonly used resorption markers serum C-telopeptides of type I collagen, urinary N-telopeptides of type I collagen and tartrate resistant acid phosphatase type 5b. BTMs are usually measured by enzyme-linked immunosorbent assay or automated immunoassay. Sources contributing to BTM variability include uncontrollable components (e.g., age, gender, ethnicity) and controllable components, particularly relating to collection conditions (e.g., fasting/feeding state, and timing relative to circadian rhythms, menstrual cycling, and exercise). Pregnancy, season, drugs, and recent fracture(s) can also affect BTMs. BTMs correlate with other methods of assessing bone turnover, such as bone biopsies and radiotracer kinetics; and can usefully contribute to diagnosis and management of several diseases such as osteoporosis, osteomalacia, Paget's disease, fibrous dysplasia, hypophosphatasia, primary hyperparathyroidism, and chronic kidney disease-mineral bone disorder.

The utility of dried blood spot measurement of bone turnover markers in biological anthropology

OBJECTIVES

Bone is a dynamic organ under continual turnover influenced by life history stage, energy dynamics, diet, climate, and disease. Bone turnover data have enormous potential in biological anthropology for testing evolutionary and biocultural hypotheses, yet few studies have integrated these biomarkers. In the present article we systematically review the current availability, future viability, and applicability of measuring bone turnover markers (BTMs) in dried blood spot (DBS) samples obtained from finger prick whole blood.

METHODS

Our review considers clinical and public health relevance, biomarker stability in DBS, assay availability, and cost. We consider biomarkers of bone formation such as osteocalcin (bone matrix protein), PINP (N-terminal propeptide of type I collagen), and alkaline phosphatase (osteoblast enzyme), as well as biomarkers of bone resorption such as CTX (marker of collagen breakdown) and TRACP5b (tartrate-resistant acid phosphatase 5b; osteoclast enzyme).

RESULTS

Two BTMs have been validated for DBS: osteocalcin (formation) and TRACP5b (resorption). Prime candidates for future development are CTX and PINP, the formation and resorption markers used for clinical monitoring of response to osteoporosis treatment.

CONCLUSION

BTMs are a field-friendly technique for longitudinal monitoring of skeletal biology during growth, reproduction and aging, combining minimized risk to study participants with maximized ease of sample storage and transport. This combination allows new insights into the effects of energy availability, disease, and physical activity level on bone, and questions about bone gain and loss across life history and in response to environmental factors; these issues are important in human biology, paleoanthropology, bioarchaeology, and forensic anthropology.

Effects of a Whole Plant Extract of Scutellaria rubropunctata var. rubropunctata on Bone Metabolism with Estrogen Receptor Activation

We screened natural resources for estrogen receptor (ER)-activating and bone metabolism-promoting activities with the aim of finding potential treatments for osteoporosis. A screen of 1531 extracts from Ryukyu Arc plants using a luciferase reporter assay identified an 80% MeOH extract of Scutellaria rubropunctata var. rubropunctata (SRE) with dose-dependent ER transcription-promoting activity. Importantly, SRE had no proliferative effect on human breast cancer cells. SRE enhanced the ALP activity of pre-osteoblast MC3T3-E1 cells after 72 h in culture and slightly enhanced mineralization at 14 and 21 d. SRE did not significantly affect the TRAP activity of RAW264.7 cells. Gene expression analysis in MC3T3-E1 cells by quantitative real-time PCR revealed that SRE upregulated the mRNA levels of Runx2, Osterix (Osx), Osteopontin (Opn), Osteocalcin (Ocn), Smad1, Smad4, and Smad5 at 72 h, and those of Runx2, Osx, Smad1, Smad4, and Smad5 at 21 d of osteogenic induction. Analysis of the expression levels of osteogenic markers suggested that SRE may promote osteogenic differentiation by acting at the early stage of differentiation rather than at the late stage of differentiation. These results indicate that SRE activates ER and induces osteoblast differentiation by activating Runx2 and Osx through the BMP/Smad pathway, suggesting that SRE may be useful for the prevention and treatment of postmenopausal osteoporosis.

Bone Remodeling in Mandible of Wistar Rats with Diabetes Mellitus and Osteoporosis

OBJECTIVES

 This study aimed to determine some of bone molecular expressions and its possible bone remodeling pathway between diabetes mellitus (DM) and osteoporosis model in the mandibular bone of Wistar rats.

MATERIALS AND METHODS

 Twenty-seven female Wistar rats were divided randomly into control and treatment groups. Treatment groups were injected with streptozotocin intraperitoneally to induce DM (P1) and underwent bilateral ovariectomy to generate osteoporosis (P2). All groups were terminated after 12 weeks. Immunohistochemical and hematoxylin-eosin staining were performed to determine the expression of Runt-related transcription factor 2 (RUNX2), Osterix, vascular endothelial growth factor (VEGF), receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), tartrate-resistant acid phosphatase (TRAP), and observed the osteoblast and osteoclast. Statistical analysis was performed using one-way analysis of variance.

RESULTS

 The lowest mean of RUNX2 and VEGF expression was found in the P2 group. The lowest mean of Osterix expression was found in the P1 group. Both P1 and P2 groups of osteoblast/osteoclast ratio were decreased. There were no significant differences in the expression of TRAP between all groups; however, increased expression of RANKL/OPG ratio was only found in the P2 group.

CONCLUSION

 DM and osteoporosis induce changes in the bone remodeling pathway which are represented by a decrease in osteoblast biomarkers and an increase in osteoclast biomarkers.

Analytical evaluation of the Nittobo Medical tartrate resistant acid phosphatase isoform 5b (TRACP-5b) EIA and comparison with IDS iSYS in different clinically defined populations

OBJECTIVES

Tartrate-resistant acid phosphatase, isoform 5b (TRACP-5b) is a bone resorption marker not influenced by renal function or food intake. TRACP-5b can be measured with Nittobo Medical enzymatic-immunoassay and IDS-iSYS automated immunoassay. We evaluated the Nittobo assay and established reference ranges for a Western-European population. We compared Nittobo and IDS results in different well-defined clinical populations.

METHODS

We established the limits of detection and quantification (LOD-LOQ), linearity, imprecision and the reference ranges in 119 males, 50 women (<45 years) and 120 women (>60 years) for TRACP-5b with the Nittobo assay. We compared both assays in 30 hemodialyzed (HD), and 40 stage 3-5 patients suffering from chronic kidney disease (CKD), 40 patients suffering from rheumatoid arthritis and osteoporosis and 80 post-menopausal women. We measured TRACP-5b, β-crosslaps (β-CTX), bone alkaline phosphatase (B-ALP) and PTH in 20 hemodialyzed (HD) and 40 CKD patients.

RESULTS

LOD and LOQ were 0.02 and 0.35 U/L. CV ranged from 8.3 to 4.3% (2/5 samples presenting CV > desirable CV). Method was linear up to of 11.3 U/L. Upper and lower limits of normality were 0.8-7.6 U/L in men, 0.9-4.7 U/L in women <45 and 0.9-7.1 U/L in women >60. The regression equation between the 2 methods was Nittobo = 1.13 (95% CI: 1.09-1.16) × iSYS - 0.4 (95% CI: -0.5; -0.3). TRACP-5b and b-ALP were in their respective reference ranges for most of CKD and HD patients. That was not the case for β-CTX, which increased with decreasing eGFR.

CONCLUSIONS

Nittobo TRACP-5b presents interesting analytical features and a good concordance with IDS iSYS. These methods could thus potentially be harmonized.

Voluntary running of defined distances alters bone microstructure in C57BL/6 mice fed a high-fat diet

Obesity increases the risk for pathological conditions such as bone loss. On the other hand, physical exercise reduces body adiposity. To test the hypothesis that physical activity improves bone quality, we evaluated voluntary running of defined distances on trabecular and cortical microstructure in mice fed a high-fat diet (HFD). Sedentary mice were fed the standard AIN93G diet or the HFD. Mice fed the HFD remained sedentary or were assigned to unrestricted running or 75%, 50%, and 25% of unrestricted running with an average running activity at 8.3, 6.3, 4.2, and 2.1 km per day, respectively. The bone structural differences found in sedentary mice were that HFD, compared with the AIN93G diet, resulted in a lower bone volume fraction (BV/TV) and a higher structure model index (SMI) in vertebrae. Running had a greater effect on trabecular microstructure in femurs than in vertebrae; the decrease in SMI and an increase in trabecular thickness (Tb.Th) were in dose-dependent manners. Running was positively correlated with BV/TV and Tb.Th and inversely correlated with SMI in femurs. The HFD increased plasma concentrations of tartrate-resistant acid phosphatase 5b, a marker of bone resorption, in sedentary mice, while running decreased it in a dose-dependent manner. The findings show that voluntary running improves bone quality in young adult mice fed an HFD. Novelty: The high-fat diet alters bone microstructure by increasing bone resorption. Quantitative voluntary running improves bone microstructure through its attenuation of bone resorption in mice fed a high-fat diet.

Diagnostic Accuracy of Noninvasive Bone Turnover Markers in Renal Osteodystrophy

RATIONALE & OBJECTIVE

Bone biopsy remains the gold standard for diagnosing renal osteodystrophy as comparable non-invasive alternatives have yet to be established. The aim of this study was to investigate the diagnostic accuracy of biochemical markers of skeletal remodeling to predict bone turnover.

STUDY DESIGN

Cross-sectional retrospective diagnostic test study.

SETTING & PARTICIPANTS

Patients with chronic kidney disease stages G4-G5D and kidney transplant recipients with successful transiliac bone biopsies.

TESTS COMPARED

Bone turnover as determined by bone histomorphometry was compared to the following biochemical markers: Full-length (1-84) parathyroid hormone (PTH), bone-specific alkaline phosphatase (BsAP), intact procollagen type I N-terminal propeptide (PINP), and tartrate-resistant acid phosphatase isoform 5b (TRAP5b).

OUTCOME

Diagnostic performance was evaluated by area under the receiver operator characteristics curve (AUC), sensitivity, specificity, and negative and positive predictive values. Optimal diagnostic cutoffs were determined in an exploration cohort (n=100) and validated in a separate cohort (n=99).

RESULTS

All biomarkers differed across categories of low 33 (17%), normal 109 (55%), and high 57 (29%) bone turnover. AUC values were in the range of 0.75 - 0.85. High negative predictive values (≥90%) were found for both high and low bone turnover, indicating the ability to rule out both conditions using the suggested biomarker cutoffs. The highest diagnostic performances were seen with combinations of biomarkers, with overall diagnostic accuracies of 90% for high turnover, and 78% for low turnover. Results were comparable for kidney transplant candidates and recipients in a sensitivity analysis.

LIMITATIONS

The single-center approach and heterogeneity of the study cohort are main limitations of this study.

CONCLUSIONS

We conclude that the diagnostic performance of biochemical markers of bone turnover is acceptable, with clinical utility in ruling out both high and low turnover bone disease.

Bisphosphonate-enoxacin inhibit osteoclast formation and function by abrogating RANKL-induced JNK signalling pathways during osteoporosis treatment

Osteoporosis is an age‐related disease characterized by low mineral density, compromised bone strength and increased risk of fragility fracture. Most agents for treating osteoporosis focus primarily on anti‐resorption by inhibiting osteoclast activity. Bisphosphonate (BP) is a potent anti‐resorptive agent that has been used clinically for decades and is proven to be effective. However, BP has a variety of side effects and is far from being an ideal anti‐osteoporosis agent. BP selectively binds to calcium crystals, which are subsequently taken up or released by osteoclasts. Based on the action of BP, we previously demonstrated the inhibitory effect of a novel bone‐targeting BP derivative, bisphosphonate‐enoxacin (BE). In the current study, we used bone marrow‐derived osteoclast cultures to further assess the inhibitory effect of BE on osteoclastogenesis and employed reverse transcription PCR and real‐time PCR to examine expression of osteoclast‐specific genes. Additionally, we used bone resorption and F‐actin immunofluorescence assays to evaluate the effect of BE on osteoclast function and investigated the potential mechanisms affecting osteoclast differentiation and function in vitro. Furthermore, an ovariectomized (OVX) rat model was established to evaluate the therapeutic effects of BE on preventing bone loss. Results showed that BE exerted potent inhibitory effects on osteoclast formation and bone resorption by specifically abrogating RANKL‐induced JNK signalling, and that it preserved OVX rat bone mass in vivo without any notable side effects. Collectively, these results indicated that the BP derivative BE may have significant potential as a treatment for osteoporosis and other osteolytic diseases.

Human osteoclast formation and resorptive function on biomineralized collagen

Biomineralized collagen composite materials pose an intriguing alternative to current synthetic bone graft substitutes by offering a biomimetic composition that closely resembles native bone. We hypothesize that this composite can undergo cellular resorption and remodeling similar to natural bone. We investigate the formation and activity of human osteoclasts cultured on biomineralized collagen and pure collagen membranes in comparison to cortical bone slices. Human monocytes/macrophages from peripheral blood differentiate into multinucleated, tartrate-resistant alkaline phosphatase (TRAP)-positive osteoclast-like cells on all substrates. These cells form clear actin rings on cortical bone, but not on biomineralized collagen or pure collagen membranes. Osteoclasts form resorption pits in cortical bone, resulting in higher calcium ion concentration in cell culture medium; however, osteoclast resorption of biomineralized collagen and collagen membranes does not measurably occur. Activity of osteoclast enzymes – TRAP, carbonic anhydrase II (CA-II), and cathepsin-K (CTS-K) – is similar on all substrates, despite phenotypic differences in actin ring formation and resorption. The mesh-like structure, relatively low stiffness, and lack of RGD-containing binding domains are likely the factors responsible for preventing formation of stable actin rings on and resorption of (biomineralized) collagen membranes. This insight helps to guide further research toward the optimized design of biomineralized collagen composites as a more biomimetic bone-graft substitute.

•

Human osteoclasts differentiated on biomineralized collagen, but no resorption occured.

•

Porous surface of fibrillary collagen and lack of RGD ligands to the vitronectin receptor likely prevented osteoclast resorption.

•

Quantification of resorption on uneven surfaces in comparison with bone was possible with 3D laser microscopy.

Rational Design of Potent Inhibitors of a Metallohydrolase Using a Fragment-Based Approach

Metallohydrolases form a large group of enzymes that have fundamental importance in a broad range of biological functions. Among them, the purple acid phosphatases (PAPs) have gained attention due to their crucial role in the acquisition and use of phosphate by plants and also as a promising target for novel treatments of bone-related disorders and cancer. To date, no crystal structure of a mammalian PAP with drug-like molecules bound near the active site is available. Herein, we used a fragment-based design approach using structures of a mammalian PAP in complex with the Maybridge^TM fragment CC063346, the amino acid L-glutamine and the buffer molecule HEPES, as well as various solvent molecules to guide the design of highly potent and efficient mammalian PAP inhibitors. These inhibitors have improved aqueous solubility when compared to the clinically most promising PAP inhibitors available to date. Furthermore, drug-like fragments bound in newly discovered binding sites mapped out additional scaffolds for further inhibitor discovery, as well as scaffolds for the design of inhibitors with novel modes of action.

Evaluation of Dexamethasone-Induced Osteoporosis In Vivo Using Zebrafish Scales

Glucocorticoid-induced osteoporosis (GIOP) is a major cause of secondary osteoporosis, and the pathogenic mechanisms of GIOP remain to be elucidated. Here, we show a rapid dexamethasone-induced osteoporosis animal model using zebrafish scales. Intraperitoneal injection of dexamethasone over a 5-day period suppressed the regeneration of scales. Furthermore, the circularity of the newly formed regenerated scales was also slightly reduced compared to that of the control group on day 5. The changes in bone-related enzymes, such as cathepsin K, tartrate-resistant acid phosphatase (TRAP) for bone resorption, and alkaline phosphatase (ALP) for bone formation, provide insight into the progression of bone diseases; therefore, we further developed a method to measure the activities of cathepsin K, TRAP, and ALP using zebrafish scales. We found that a lysis buffer with detergent at neutral pH under sonication efficiently helped extract these three enzymes with high activity levels. Interestingly, treatment with a dexamethasone injection produced considerably higher levels of cathepsin K activity and a lower Ca/P ratio than those in the control group, suggesting that dexamethasone increased osteoclast activity, with no significant changes in the activities of TRAP and ALP. Our GIOP model and enzyme assay method could help to design better treatments for GIOP.

Metformin: Is It the Well Wisher of Bone Beyond Glycemic Control in Diabetes Mellitus?

Both diabetes mellitus and osteoporosis constitute a notable burden in terms of quality of life and healthcare costs. Diabetes mellitus affecting the skeletal system has been gaining attention in recent years and is now getting recognized as yet another complication of the disease, known as diabetic bone disease. As this condition with weaker bone strength increases fracture risk and reduces the quality of life, so much attention is being paid to investigate the molecular pathways through which both diabetes and its therapy are affecting bone metabolism. Out of many therapeutic agents currently available for managing diabetes mellitus, metformin is one of the most widely accepted first choices worldwide. The purpose of this review is to describe the effects of biguanide-metformin on bone metabolism in type 2 diabetes mellitus including its plausible mechanisms of action on the skeleton. In vitro studies suggest that metformin directly stimulates osteoblasts differentiation and may inhibit osteoclastogenesis by increasing osteoprotegerin expression, both through activation of the AMPK signaling pathway. Several studies in both preclinical and clinical settings report the favorable effects of metformin on bone microarchitecture, bone mineral density, bone turnover markers, and fracture risk. However, animal studies were not specific in terms of the diabetic models used and clinical studies were associated with several confounders. The review highlights some of these limitations and provide future recommendations for research in this area which is necessary to better understand the role of metformin on skeletal outcomes in diabetes.

Acid-Induced Inflammatory Cytokines in Osteoblasts: A Guided Path to Osteolysis in Bone Metastasis

Bone metastasis (BM) is a dismal complication of cancer that frequently occurs in patients with advanced carcinomas and that often manifests as an osteolytic lesion. In bone, tumor cells promote an imbalance in bone remodeling via the release of growth factors that, directly or indirectly, stimulate osteoclast resorption activity. However, carcinoma cells are also characterized by an altered metabolism responsible for a decrease of extracellular pH, which, in turn, directly intensifies osteoclast bone erosion. Here, we speculated that tumor-derived acidosis causes the osteoblast–osteoclast uncoupling in BM by modulating the pro-osteoclastogenic phenotype of osteoblasts. According to our results, a low pH recruits osteoclast precursors and promotes their differentiation through the secretome of acid-stressed osteoblasts that includes pro-osteoclastogenic factors and inflammatory mediators, such as RANKL, M-CSF, TNF, IL-6, and, above the others, IL-8. The treatment with the anti-IL-6R antibody tocilizumab or with an anti-IL-8 antibody reverted this effect. Finally, in a series of BM patients, circulating levels of the osteolytic marker TRACP5b significantly correlated with IL-8. Our findings brought out that tumor-derived acidosis promotes excessive osteolysis at least in part by inducing an inflammatory phenotype in osteoblasts, and these results strengthen the use of anti-IL-6 or anti-IL-8 strategies to treat osteolysis in BM.

TRAP5b and RANKL/OPG Predict Bone Pathology in Patients with Gaucher Disease

Background and objective: Bone involvement occurs in 75% of patients with Gaucher disease (GD), and comprises structural changes, debilitating pain, and bone density abnormalities. Osteoporosis is a silent manifestation of GD until a pathologic fracture occurs. Thus, early diagnosis is crucial for identifying high-risk patients in order to prevent irreversible complications. Methods: Thirty-three patients with GD were assessed prospectively to identify predictive markers associated with bone density abnormalities, osteopenia (OSN), and osteoporosis (OSR). Subjects were categorized into three cohorts based on T- or Z-scores of bone mineral density (BMD). The first GD cohort consisted of those with no bone complications (Z-score ≥ −0.9; T-scores ≥ −1), the second was the OSN group (−1.8 ≥ Z-score ≥ −1; −2.5 ≥ T-score ≥ −1), and the third was the OSR group (Z-score ≤ −1.9; T-scores ≤ −2.5). Serum levels of TRAP5b, RANKL, OPG, and RANK were quantified by enzyme-linked immunosorbent assays. Results: TRAP5b levels were increased in GD patients, and showed a positive correlation with GD biomarkers, including plasma glucosylsphingosine (lyso-Gb1) and macrophage activation markers CCL18 and chitotriosidase. The highest level of TRAP5b was measured in patients with osteoporosis. The elevation of RANKL and RANKL/OPG ratio correlated with osteopenia in GD. Conclusion: TRAP5b, RANKL, and RANKL/OPG elevation indicate osteoclast activation in GD. TRAP5b is a potential bone biomarker for GD with the ability to predict the progression of bone density abnormalities.

Sympathetic activity in breast cancer and metastasis: partners in crime

The vast majority of patients with advanced breast cancer present skeletal complications that severely compromise their quality of life. Breast cancer cells are characterized by a strong tropism to the bone niche. After engraftment and colonization of bone, breast cancer cells interact with native bone cells to hinder the normal bone remodeling process and establish an osteolytic "metastatic vicious cycle". The sympathetic nervous system has emerged in recent years as an important modulator of breast cancer progression and metastasis, potentiating and accelerating the onset of the vicious cycle and leading to extensive bone degradation. Furthermore, sympathetic neurotransmitters and their cognate receptors have been shown to promote several hallmarks of breast cancer, such as proliferation, angiogenesis, immune escape, and invasion of the extracellular matrix. In this review, we assembled the current knowledge concerning the complex interactions that take place in the tumor microenvironment, with a special emphasis on sympathetic modulation of breast cancer cells and stromal cells. Notably, the differential action of epinephrine and norepinephrine, through either α- or β-adrenergic receptors, on breast cancer progression prompts careful consideration when designing new therapeutic options. In addition, the contribution of sympathetic innervation to the formation of bone metastatic foci is highlighted. In particular, we address the remarkable ability of adrenergic signaling to condition the native bone remodeling process and modulate the bone vasculature, driving breast cancer cell engraftment in the bone niche. Finally, clinical perspectives and developments on the use of β-adrenergic receptor inhibitors for breast cancer management and treatment are discussed.

Anti-osteoporotic effects of alisol C 23-acetate via osteoclastogenesis inhibition

Alismatis rhizoma (AR) is the dried rhizome of Alisma orientale (Sam.) Juz. (Alismataceae). This traditional Chinese formula is diuretic, hypoglycemic, and hypolipidemic. Alisol C 23-acetate (AC23A) from AR is anti-inflammatory and ameliorates certain metabolic diseases. However, the mechanism by which AC23A mitigates osteoporosis is unknown. The present study investigated the anti-osteoporotic effects of AC23A in vivo and in vitro. In an ovariectomized (OVX) rat model, AC23A ameliorated OVX-induced organ coefficients and trabecular bone loss. In OVX rats, AC23A treatment lowered serum TRAP5b, CTK, β-CTX, TNF-α, IL-6, and IL-1β, raised serum E2, and did not significantly change serum OCN or BALP. AC23A inhibited osteoclast formation in a rat co-culture system without affecting osteoblast activity. RANK (receptor activator of nuclear factor kappaB) signaling channels are vital osteoclastogenesis transcription elements. AC23A inhibited RANK ligand (RANKL)-induced TRAP, c-Fos, MMP9, NFATc1, and CTK expression and JNK phosphorylation. Therefore, AC23A is anti-osteoclastogenic in vitro and in vivo by inhibiting RANKL-induced osteoclast differentiation and function. Moreover, AC23A could help prevent or limit osteoclast-mediated bone diseases by inhibiting osteoclastogenesis.

A fraction of Pueraria tuberosa extract, rich in antioxidant compounds, alleviates ovariectomized-induced osteoporosis in rats and inhibits growth of breast and ovarian cancer cells

Pueraria tuberosa (Roxb. ex Willd.) DC., known as Indian Kudzu belongs to family Fabaceae and it is solicited as “Rasayana” drugs in Ayurveda. In the present study, we analyzed the efficacy of an ethyl acetate fraction from the tuber extract of Pueraria tuberosa (fraction rich in antioxidant compounds, FRAC) against menopausal osteoporosis, and breast and ovarian cancer cells. The FRAC from Pueraria tuberosa was characterized for its phenolic composition (total phenolic and flavonoid amount). Antioxidant property (in vitro assays) of the FRAC was also carried out followed by the analysis of the FRAC for its antiosteoporotic and anticancer potentials. The antiosteoporotic activity of FRAC was investigated in ovariectomy-induced osteoporosis in rats. The cytotoxicity effect was determined in breast and ovarian cancer cells. Gas chromatography/mass spectrometry (GC/MS) analysis of the FRAC was performed to determine its various phytoconstituents. Docking analysis was performed to verify the interaction of bioactive molecules with estrogen receptors (ERs). The FRAC significantly improved various biomechanical and biochemical parameters in a dose-dependent manner in the ovariectomized rats. FRAC also controlled the increased body weight and decreased uterus weight following ovariectomy in rats. Histopathology of the femur demonstrated the restoration of typical bone structure and trabecular width in ovariectomized animals after treatment with FRAC and raloxifene. The FRAC also exhibited in vitro cytotoxicity in the breast (MCF-7 and MDA-MB-231) and ovarian (SKOV-3) cancer cells. Furthermore, genistein and daidzein exhibited a high affinity towards both estrogen receptors (α and β) in the docking study revealing the probable mechanism of the antiosteoporotic activity. GC/MS analysis confirmed the presence of other bioactive molecules such as stigmasterol, β-sitosterol, and stigmasta-3,5-dien-7-one. The FRAC from Pueraria tuberosa has potential for treatment of menopausal osteoporosis. Also, the FRAC possesses anticancer activity.

A fraction of Pueraria tuberosa extract, rich in antioxidant compounds, alleviates ovariectomized-induced osteoporosis in rats and inhibits growth of breast and ovarian cancer cells

Pueraria tuberosa (Roxb. ex Willd.) DC., known as Indian Kudzu belongs to family Fabaceae and it is solicited as "Rasayana" drugs in Ayurveda. In the present study, we analyzed the efficacy of an ethyl acetate fraction from the tuber extract of Pueraria tuberosa (fraction rich in antioxidant compounds, FRAC) against menopausal osteoporosis, and breast and ovarian cancer cells. The FRAC from Pueraria tuberosa was characterized for its phenolic composition (total phenolic and flavonoid amount). Antioxidant property (in vitro assays) of the FRAC was also carried out followed by the analysis of the FRAC for its antiosteoporotic and anticancer potentials. The antiosteoporotic activity of FRAC was investigated in ovariectomy-induced osteoporosis in rats. The cytotoxicity effect was determined in breast and ovarian cancer cells. Gas chromatography/mass spectrometry (GC/MS) analysis of the FRAC was performed to determine its various phytoconstituents. Docking analysis was performed to verify the interaction of bioactive molecules with estrogen receptors (ERs). The FRAC significantly improved various biomechanical and biochemical parameters in a dose-dependent manner in the ovariectomized rats. FRAC also controlled the increased body weight and decreased uterus weight following ovariectomy in rats. Histopathology of the femur demonstrated the restoration of typical bone structure and trabecular width in ovariectomized animals after treatment with FRAC and raloxifene. The FRAC also exhibited in vitro cytotoxicity in the breast (MCF-7 and MDA-MB-231) and ovarian (SKOV-3) cancer cells. Furthermore, genistein and daidzein exhibited a high affinity towards both estrogen receptors (α and β) in the docking study revealing the probable mechanism of the antiosteoporotic activity. GC/MS analysis confirmed the presence of other bioactive molecules such as stigmasterol, β-sitosterol, and stigmasta-3,5-dien-7-one. The FRAC from Pueraria tuberosa has potential for treatment of menopausal osteoporosis. Also, the FRAC possesses anticancer activity.

Dietary supplementation of 25-hydroxycholecalciferol increases tibial mass by suppression bone resorption in meat ducks

Leg problems often result from the rapid weight gain and poor bone quality in modern ducks, leading to a high risk of fractures and continuous pain. We hypothesized that improving bone quality in combination with delaying weight gain via a low nutrient density (LND) diet probably reverses these skeletal abnormalities. Studies indicated that 25-hydroxycholecalciferol (25-OH-D₃), a vitamin D₃ metabolite, is effective in treating bone-related disorders. Therefore, Exp. 1 evaluated the effects of 25-OH-D₃ on tibial mass of meat ducks. Male meat ducklings were fed a standard nutrient density diet (containing a regular vitamin regimen) without or with 25-OH-D₃ at 0.069 mg/kg for 35 d. The results showed that 25-OH-D₃ supplementation improved the mineral content, microarchitecture and mechanical properties of tibias, and this companied by a decreased serum bone resorption marker and a concomitant decrement in osteoclast-specific marker genes expression. Subsequently, Exp. 2 was conducted to examine the impacts of 25-OH-D₃ incorporating an LND diet on tibial quality of ducks under 2 different vitamin regimens (regular and high). Ducklings were allocated to a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes and without or with 25-OH-D₃ at 0.069 mg/kg in LND diets. The high premix had higher levels of all vitamins except biotin than the regular premix. The results demonstrated that high vitamin diets exhibited more significant effects than regular vitamin diets on inhibiting bone turnover and increasing minerals deposition. Tibial mineral content, microarchitecture, and strength of birds under the regular vitamin regimen were increased by 25-OH-D₃ supplementation; However, these positive effects were not observed in ducks under the high vitamin regimen. To conclude, 25-OH-D₃ supplementation improves tibial mass by suppressing osteoclast-mediated bone resorption in meat ducks, and this positive impact only was observed in regular but not high vitamin regimen when birds fed an LND diet.

Glucocorticoid effects on bone strength in children with renal diseases

AIM

Glucocorticoids (GC) are essential medicines for idiopathic steroid-sensitive nephrotic syndrome (ISSNS) and IgA nephropathy (IgAN), with good clinical results. However, they cause bone fragility. The aim of this study was to elucidate GC effects on bone strength assessed as bone mineral density (BMD) and bone quality, using bone turnover markers (BTM), in children with ISSNS or IgAN.

METHODS

Eleven children with ISSNS and 13 with IgAN were included. All the patients received GC treatment according to each protocol. The BMD and BTM-serum alkaline phosphatase (S-ALP), tartrate-resistant acid phosphatase 5b (S-TRACP-5b), and undercarboxylated osteocalcin (S-ucOC)-were measured from the initiation of steroid treatment (STx) to the end of STx in both groups.

RESULTS

In ISSNS, S-ALP and S-ucOC levels were decreased significantly at 1 month. BMD and S-TRACP-5b levels showed no significant change through this observation period. In IgAN, BMD and S-ALP levels were decreased significantly at 1 and 3 months, respectively, and recovered to baseline at 10 months after the initiation of GC dosage reduction. S-TRACP-5b levels were decreased significantly at 3 months and remained lower than at baseline through the observation period. In both groups, S-ucOC levels did not directly reflect bone strength.

CONCLUSION

This study clarified the following three points regarding GC effects on bone strength in children with ISSNS or IgAN: first, S-ALP is a more sensitive bone quality marker than S-TRACP-5b; second, BMD loss was observed only when both S-ALP and S-TRACP-5b levels decreased, and third, S-ucOC levels do not directly reflect bone strength.

LncRNA TUG1 positively regulates osteoclast differentiation by targeting v-maf musculoaponeurotic fibrosarcoma oncogene homolog B

Osteoclast differentiation-mediates bone resorption is the key biological basis of orthodontic treatment while the specific mechanism of osteoclastogenesis remains unclear. This study aims to explore the underlying mechanism of the osteoclast differentiation from the perspective of long non-coding RNA (LncRNA). In the present study, the osteoclast differentiation of CD14⁺ peripheral blood mononuclear cells (PBMCs) was induced by recombinant human macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor κB ligand (RANKL), and LncRNA TUG1 expression was dramatically elevated during this process. Functionally, the silence of TUG1 in CD14⁺ PBMCs decreased tartrate-resistant acid phosphatase (TRAP)-positive cell numbers and the protein levels of TRAP, nuclear factor of activated T cell c1 (NFATc1), and osteoclast-associated receptor (OSCAR), whereas increased V-maf musculoaponeurotic fibrosarcoma oncogene homolog B (MafB) protein level. The subsequent experiments confirmed that TUG1 lessened the MafB protein level via accelerating its degradation. Then, the interference of MafB reversed the inhibitory effect of si-TUG1 on osteoclastogenesis, including increased the TRAP-positive cell numbers and up-regulated the protein levels of osteoclast markers. Finally, the in vivo experiments displayed that the increased TUG1 levels could promote tooth movement and bone resorption via facilitating osteoclast differentiation in the rat model of orthodontic tooth movement. In summary, TUG1 overexpressed during the process of osteoclast differentiation and positively regulated osteoclast differentiation by targeting MafB.

Intensive weight gain therapy in patients with anorexia nervosa results in improved serum tartrate-resistant acid phosphatase (TRAP) 5a and 5b isoform protein levels

AIM

Tartrate-resistant acid phosphatase (TRAP) exists as isoforms 5a and 5b. TRAP 5a is a biomarker of chronic inflammation and influences adipose tissue and 5b associates with bone metabolism/pathologies. The aim was to investigate the association of serum TRAP 5a/5b isoforms with fat and bone markers and anthropometric parameters in patients with anorexia nervosa (AN) during weight gain therapy.

METHODS

Twenty-five Swedish female AN patients, age 16-24 years, were treated for 12 weeks with a high-energy diet with six meals daily. Serum TRAP 5a/5b, markers of fat/glucose metabolism, markers of bone resorption and formation were measured. Parameters of bone and body composition were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography.

RESULTS

BMI increased from median 15.4 kg/m² to 19.0 kg/m², p < 0.0001. TRAP 5a and 5a/5b ratio increased but TRAP 5b decreased during the study. TRAP Δ5a and Δ5b correlated with Δinsulin and Δadiponectin, respectively. TRAP 5b correlated with trabecular density at start but not at week 12. At 12 weeks, TRAP 5b correlated with CTX, and Δ decrease in TRAP 5b correlated to Δ increase in bone-specific alkaline phosphatase.

CONCLUSIONS

This clinical interventional study resulted in increased BMI in patients with AN. The decreased TRAP 5b protein levels confirm a role for TRAP 5b as a marker of bone resorption, whereas increased TRAP 5a seemed to derive from systemic changes in bone as well as metabolic changes. The combined detection of TRAP 5a and TRAP 5b in serum could be an indicator of improved bone metabolism.

LEVEL OF EVIDENCE

Level III, prospective interventional cohort study.

Advances in Sensing Technologies for Monitoring of Bone Health

: Changing lifestyle and food habits are responsible for health problems, especially those related to bone in an aging population. Poor bone health has now become a serious matter of concern for many of us. In order to avoid serious consequences, the early prediction of symptoms and diagnosis of bone diseases have become the need of the hour. From this inspiration, the evolution of different bone health monitoring techniques and measurement methods practiced by researchers and healthcare companies has been discussed. This paper focuses on various types of bone diseases along with the modeling and remodeling phenomena of bones. The evolution of various diagnosis tests for bone health monitoring has been also discussed. Various types of bone turnover markers, their assessment techniques, and recent developments for the monitoring of biochemical markers to diagnose the bone conditions are highlighted. Then, the paper focuses on the potential assessment of the recent sensing techniques (physical sensors and biosensors) that are currently available for bone health monitoring. Considering the importance of electrochemical biosensors in terms of high sensitivity and reliability, specific attention has been given to the recent development of electrochemical biosensors and significance in real-time monitoring of bone health.

Osteoporosis and the Potential of Cell-Based Therapeutic Strategies

Osteoporosis, the most common chronic metabolic bone disease, is characterized by low bone mass and increased bone fragility. Nowadays more than 200 million individuals are suffering from osteoporosis and still the number of affected people is dramatically increasing due to an aging population and longer life, representing a major public health problem. Current osteoporosis treatments are mainly designed to decrease bone resorption, presenting serious adverse effects that limit their safety for long-term use. Numerous studies with mesenchymal stem cells (MSCs) have helped to increase the knowledge regarding the mechanisms that underlie the progression of osteoporosis. Emerging clinical and molecular evidence suggests that inflammation exerts a significant influence on bone turnover, thereby on osteoporosis. In this regard, MSCs have proven to possess broad immunoregulatory capabilities, modulating both adaptive and innate immunity. Here, we will discuss the role that MSCs play in the etiopathology of osteoporosis and their potential use for the treatment of this disease.

A Novel Sandwich ELISA for Tartrate-Resistant Acid Phosphatase 5a and 5b Protein Reveals that Both Isoforms are Secreted by Differentiating Osteoclasts and Correlate to the Type I Collagen Degradation Marker CTX-I In Vivo and In Vitro

Tartrate-resistant acid phosphatase type 5 (TRAP) exists as two isoforms, 5a and 5b. 5b is a marker of osteoclast number and 5a of chronic inflammation; however, its association with bone resorption is unknown. In this study, a double-TRAP 5a/5b sandwich ELISA measuring 5a and 5b protein in the same sample was developed. TRAP 5a and 5b protein levels were evaluated as osteoclast differentiation/activity markers in serum and in culture, and their correlation to the resorption marker CTX-I was examined. Serum TRAP 5a and 5b concentrations in healthy men were 4.4 ± 0.6 ng/ml and 1.3 ± 0.2 ng/ml, respectively, and they correlated moderately to each other suggesting that their secretion is coupled under healthy conditions. A correlation was also observed between serum TRAP 5a and 5b with CTX-I, suggesting that both TRAP isoforms associate with osteoclast number. During osteoclast differentiation on plastic/bone, predominantly 5b increased in media/lysate from M-CSF/RANKL-stimulated CD14+ PBMCs. However, substantial levels of 5a were detected at later stages suggesting that both isoforms are secreted from differentiating OCs. More TRAP 5b was released on bone indicating a connection to osteoclast resorptive activity, and a peak in TRAP 5b/5a-ratio coincided with rapid CTX-I release. At the end of the culture period of M-CSF + RANKL-stimulated CD14+ PBMCs, there was a correlation between the secretion of TRAP 5a and 5b proteins with CTX-I. The correlation of not only 5b but also 5a with collagen degradation, both in serum and osteoclast cultures indicates that a considerable proportion of the TRAP 5a originates from osteoclasts and may reflect a hitherto undisclosed regulatory mechanism during bone resorption and bone remodeling.

Serum Concentration of Bone Metabolism Biomarkers in Goats during the Transition Period

Objective

During the transition period, the animal experiences a series of nutritional, physiological, and social changes. The objective of the present study was to evaluate the influence of the periparturient period in goats on the serum concentrations of the bone biomarkers osteocalcin (OC), bone-specific alkaline phosphatase (b-ALP), and pyridinoline cross-links (PYD).

Method

Blood samples were collected from fifteen female goats during the periparturient period 3 wk before expected parturition (T -3), within 12 h of parturition (T -3), within 12 h of parturition (T -3), within 12 h of parturition (.

Results

Compared to a value of 77.67 ± 47.6 ng/mL at T -3), within 12 h of parturition (T -3), within 12 h of parturition (T -3), within 12 h of parturition (T -3), within 12 h of parturition (T -3), within 12 h of parturition (T -3), within 12 h of parturition (P > 0.05). Compared to a value of 42.00 ± 19.50 U/L at T -3), within 12 h of parturition (T -3), within 12 h of parturition (T -3), within 12 h of parturition (T -3), within 12 h of parturition (T -3), within 12 h of parturition (T -3), within 12 h of parturition (P > 0.05). Compared to a value of 42.00 ± 19.50 U/L at T -3), within 12 h of parturition (T -3), within 12 h of parturition (P > 0.05). Compared to a value of 42.00 ± 19.50 U/L at T -3), within 12 h of parturition (T -3), within 12 h of parturition (P > 0.05). Compared to a value of 42.00 ± 19.50 U/L at.

Conclusion

The results of this study showed that the bone formation biomarkers (OC and b-ALP) did not change significantly during the periparturient period, while the bone resorption biomarker decreased significantly at parturition compared to 3 wk before and 3 wk after parturition. The significantly increased serum estrogen around parturition may have had a role in the increased bone resorption at this time.

A chitosan film containing quercetin-loaded transfersomes for treatment of secondary osteoporosis

Osteoporosis, due to its prevalence worldwide, is a serious health problem. Topical administration of quercetin, a phytoestrogen, in the form of deformable transfersomes, could be used to treat osteoporosis to overcome its low oral solubility and bioavailability. Formulation process of transfersomes was screened by fractional factorial design and further optimized using full factorial design. Transfersomes showed good characteristics such as entrapment efficiency, particle size, zeta potential, and polydispersity index (83.0 ± 2.2%, 75.95 ± 2 nm, - 13.6 ± 6 mv and 0.333, respectively). Transfersomes were further loaded into chitosan film and showed good permeation through rat skin. Further, glucocorticoid-induced osteoporosis rat model showed induction of osteoporosis after day 30. On day 45, treatment with chitosan film containing quercetin-loaded transfersomes showed remarkable rise in femur thickness, length, density as well as in serum biochemical parameters such as calcium, phosphorous, alkaline phosphatase, and tartrate-resistant alkaline phosphatase compared to positive control group. Tensile strength of osteoporotic femur bone was also found to be increased and was comparable with normal group. Histomicrographic analysis of femur bone exhibited less disruptive and lytic changes. Thus, all the above findings indicated the beneficial effects of quercetin-loaded transfersome chitosan film, due to decline in osteoclastogenesis and osteoblast apoptosis, which further favored increase in osteoblast numbers and mineralization of bones. Thus, chitosan film containing quercetin-loaded transfersomes was found to be good alternative to oral administration of quercetin to treat osteoporosis, while easy applicability of film in the form of wrist band anytime, anywhere, and even at work achieve patient compliance. Graphical abstract.

Study on the morphology and mineralization of the tibia in meat ducks from 1 to 56 d

The objective of this current study was to characterize the basic physiological data on morphological and mineralized properties of the tibia from 1 to 56 days, as well as the interrelationships of body weight (BW) and bone traits for meat ducks. A total of 176 1-d-old ducks was allocated into eight pens and fed with the same diet until the age of 56 d. Eight birds (1 ducks/pen) were randomly selected weekly for measuring BW and tibia characteristics. The BW of duck was increased with age throughout the whole study. Tibial length and width rapidly grew from 1 to 35 d, when it leveled off. The fat-free weight, ash, calcium (Ca) and phosphorus (P) content of tibia increased rapidly from 1 to 42 d and reached its plateau from 42 d onward. Tibial density and tibia-breaking strength increased in a regular manner with age until 42 d. Serum alkaline phosphatase activity was higher between 1 to 7 d in the duck. Regression and ontogenetic scaling analysis showed the age of maximal growth rate in tibia dimension and mineralization was earlier than that in BW; when compared with BW, tibial fat-free weight and tibia-breaking strength increased isometrically, tibia length displayed a negative allometry, and tibial width showed a positive allometric growth. Results indicate that the tibia displayed rapid bone growth (1 to 35 d) and mineralization (1 to 42 d), and alkaline phosphatase (ALP) plays a critical role in the early stage of tibia mineralization of meat duck. Intensive selection for growth rate in ducks has resulted in tibial morphology changes, which represents an interesting compromise of adaptation for increasing BW.

Assessing the Effectiveness of Panchatikta Ghrita, a Classical Ayurvedic Formulation as Add-on Therapy to Vitamin D3 and Calcium Supplements in Patients with Osteopenia: A Randomized, Open-Labeled, Comparative, Controlled Clinical Study

Objectives: To assess the change in the bone mineral density (BMD) score, bone-specific biomarkers (serum vitamin D₃, tartrate-resistant acid phosphatase 5b [TRAP-5b], and osteocalcin), quality of life, Ayurvedic symptoms (Asthikshaya Lakshanas), and fracture risk assessment tool (FRAX) scores following treatment with Panchatikta Ghrita (PG), a classical herbal formulation as add-on therapy to calcium and vitamin D₃ supplements. Study design: Randomized, open-labeled, comparative, controlled clinical study. Location: TN Medical College and BYL Nair Hospital, Mumbai, India. Study participants: Eighty adult patients, aged between 40 and 75 years, diagnosed to have osteopenia (BMD T-score between -1 and -2.5 in at least two of the three joints tested-lumbar spine L1-L4, left femur-neck, left forearm-radius total). Study intervention: Treatment group received two tablespoons of PG (10 mL in lukewarm milk) along with calcium and vitamin D₃ supplements twice a day, whereas control group received only calcium and vitamin D₃ supplements twice a day for a period of 12 months. Outcome measures: BMD, bone-specific biomarkers (vitamin D₃, TRAP-5b, and osteocalcin), quality of life, Ayurvedic symptoms, and FRAX scores were evaluated before and at 6 and 12 months. Results: Eighty patients were enrolled; of which, 65 patients completed the study while 15 patients dropped out. Improvement in the BMD scores was observed at 6 and 12 months with the maximum benefit in the lumbar spine region. Significant improvement in the bone-specific biomarkers, namely serum vitamin D₃ (p < 0.001), osteocalcin (p < 0.001), and TRAP-5b (p < 0.05), was observed in the PG-treated group compared with the standard treatment group. Improvement in the quality of life, Ayurvedic symptoms scores, and risk reduction in FRAX scores of major osteoporotic fracture risk and hip fracture risk was greater with PG, although not statistically significant. Conclusions: The study findings demonstrate that PG slows down the bone degeneration processes by its stabilizing effect on the bone-specific biomarkers, indicating its potential usefulness as preventive therapy in osteopenia. The positive improvement noted in this study needs to be confirmed in studies with a larger sample size and longer duration.

Use of Polyphenol Tannic Acid to Functionalize Titanium with Strontium for Enhancement of Osteoblast Differentiation and Reduction of Osteoclast Activity

Implant anchorage remains a challenge, especially in porous osteoporotic bone with high osteoclast activity. The implant surface is modified with osteogenic molecules to stimulate osseointegration. Strontium (Sr) is known for its osteogenic and anti-osteoclastogenic effects. In this study, Sr was immobilized on a titanium (Ti) surface using bioinspired polyphenol tannic acid (pTAN) coating as an ad-layer (Ti-pTAN). Two separate coating techniques were employed for comparative analysis. In the first technique, Ti was coated with a tannic acid solution containing Sr (Ti-pTAN-1Stp). In the second method, Ti was first coated with pTAN, before being immersed in a SrCl2 solution to immobilize Sr on Ti-pTAN (Ti-pTAN-2Stp). Ti-pTAN-1Stp and Ti-pTAN-2Stp augmented the alkaline phosphatase activity, collagen secretion, osteocalcin production and calcium deposition of MC3T3-E1 cells as compared to those of Ti and Ti-pTAN. However, osteoclast differentiation of RAW 264.7, as studied by TRAP activity, total DNA, and multinucleated cell formation, were decreased on Ti-pTAN, Ti-pTAN-1Stp and Ti-pTAN-2Stp as compared to Ti. Of all the substrates, osteoclast activity on Ti-pTAN-2Stp was the lowest. Hence, an economical and simple coating technique using pTAN as an adlayer preserved the dual biological effects of Sr. These results indicate a promising new approach to tailoring the cellular responses of implant surfaces.

Anti-Disuse Osteoporosis Activity of a Complex of Calcium-Binding Peptide from Auricularia auricula Protein Hydrolysates

Osteoporosis is a common metabolic bone disease that is often seen in bedridden patients and astronauts. Long-term bed rest and nonweight bearing tend to induce disuse osteoporosis. Calcium supplements are commonly used to help treat disuse osteoporosis along with medications, most of which are calcium carbonate based, but they have poor absorption effects. In this study, we prepared a novel Auricularia auricula peptide-calcium complex (AP-Ca) and evaluated its protective effects on disuse osteoporosis. In vitro assays showed that AP-Ca significantly increased the contents of calcium (P < 0.05) and the activity of alkaline phosphatase (AKP; P < 0.05) of osteoblasts cultured in a two-dimensional-rotating wall vessel. Meanwhile, supplementation with AP-Ca also inhibited the production of pro-inflammatory factors induced by the loss of stress, especially TNF-α (P < 0.05). In vivo, a mouse tail suspension (TS) model was established, and the results showed that AP-Ca helped to improve bone mineral density, bone mineral content, and bone organic content in TS mice and effectively alleviated the alteration of enzymes related to bone metabolism, including AKP (P < 0.05) and serum tartrate-resistant acid phosphatase (P < 0.05), to avoid more serious bone loss induced by TS. Furthermore, we found that AP-Ca downregulated the bone resorption-associated pro-inflammatory genes interleukin-1 (IL-1), tumor necrosis factor-α, and IL-6 by 59.53 ± 3.55%, 48.01 ± 5.68%, and 40.00 ± 5.89%, respectively (P < 0.05). In conclusion, AP-Ca showed potential to suppress bone loss induced by disuse and might be considered a new alternative to reduce the risk of disuse osteoporosis. PRACTICAL APPLICATION: This peptide-calcium complex supplement exhibited protective effects on the bone loss induced by disuse, which provided a new alternative for patients and astronauts to reduce the risk of disuse osteoporosis.

Bioinspired polydopamine and polyphenol tannic acid functionalized titanium suppress osteoclast differentiation: a facile and efficient strategy to regulate osteoclast activity at bone-implant interface

Osseointegration of metallic implants in porous osteoporotic bone remains a challenge. Surface modification of implants to reduce peri-implant osteoclastic bone resorption was explored in the study. Bioinspired polydopamine (pDOP) and polyphenol tannic acid (pTAN) are nature-derived universal coating systems that have emerged either as a sole coating or ad-layer for biomolecular conjugation on different biomaterials. The effects pDOP and pTAN on osteoclast development have not been reported before. In this study, osteoclast development was investigated on titanium (Ti) substrates coated with pDOP (Ti-pDOP) and pTAN (Ti-pTAN). The results showed that Ti-pDOP and Ti-pTAN coating reduced tartrate-resistant acid phosphatase activity and osteoclast cell number as compared with pristine Ti. Intriguingly, the reduction was higher on Ti-pTAN than on Ti-pDOP. Economical and biocompatible tannic acid serves as a superior coating in decreasing osteoclast activity when compared with that of pDOP coating and could be used to modulate osteoclast activity at bone-implant interfaces.

Hybrid particles derived from alendronate and bioactive glass for treatment of osteoporotic bone defects

Novel hybrid particles are synthesized using alendronate and bioactive glass, which can stimulate regeneration of osteoporotic bone defects.

Effect of escitalopram and carbidopa on bone markers in Wistar rats: a preliminary experimental study

In view of the opposite effects of gut and brain serotonin in bone, the key role of Wnt β/catenin pathway in osteoblastic proliferation and the controversial bony effects of selective serotonin reuptake inhibitors antidepressants, the present study investigated the effects of escitalopram alone and in combination with carbidopa (to block gut-derived serotonin) on markers of bone turnover and Wnt signaling and micro-CT in male Wistar rats. Escitalopram (2.0 mg/kg, p.o.) and carbidopa (10 mg/kg, p.o.) were administered daily for 40 days following which indicators of reduced (dickkopf-1, sclerostin), and increased (alkaline phosphatase) bone formation and bone resorption markers (receptor activator of nuclear factor κB ligand, tartrate-resistant acid phosphatase 5b) were determined. Our results indicated that escitalopram adversely affected bone as indicated by reduced bone formation and enhanced bone resorption. Further, the effects of escitalopram on bone formation were possibly mediated through gut serotonin while the mechanisms responsible for effects on resorption seem unrelated to gut serotonin. The promising effects of carbidopa on bone formation, as observed in our study, open up exciting possibilities for this drug requiring further investigations.

Anti-arthritic effect of pentosan polysulfate in rats with collagen-induced arthritis

Pentosan polysulfate (PPS) is currently under investigation as a potential disease-modifying antiarthritic agent. In the present study the effects of PPS on arthritic profiles based on clinical score, ankle size, histological changes, and activity of inflammatory mediators using collagen-induced arthritic rat are reported. Model of arthritis was developed in Sprague Dawley rats by intradermal injection of bovine type II collagen emulsified with incomplete Freund's adjuvant. The rats were randomly divided into four groups: normal control, arthritic control, arthritic rats treated with PPS (at dose level 20 μg/g) and arthritic rats treated with meloxicam (2 μg/g). The treatment was continued daily until the day 30. Arthritic biomarkers (cartilage oligomeric matrix protein and tartrate-resistant acid phosphatase 5b) in synovial fluid, expression of inflammatory mediators (interleukin-1β, and tumor necrosis factor-α) and osteoclast marker genes (cathepsin K, tartrate-resistant acid phosphatase) in synovial membrane were measured. Daily administration of PPS to the arthritic rats significantly decreased the severity of arthritis by effectively suppressing the symptoms of arthritis and improving the functional recovery based on clinical score and histopathological evidence. Intriguingly, identical downregulation pattern of arthritis profiles, biological markers as well as relative mRNA levels of osteoclast markers and cytokines were monitored in arthritic rats treated with PPS. In conclusion, PPS exerted protective effects against collagen-induced arthritis in rats. The results suggest that PPS acts as an anti-inflammatory and anti-arthritic agent in decreasing the arthritic effects in collagen-induced arthritic rats.