Achyranthes bidentata polysaccharide suppresses osteoclastogenesis and bone resorption via inhibiting RANKL signaling

Purification of triterpenoid saponins and 25R/25S-inokosterone from Achyranthes bidentata Bl. by high-speed countercurrent chromatography coupled silver nitrate coordination

An effective method by high-speed countercurrent chromatography coordinated with silver nitrate for the preparative separation of sterones and triterpenoid saponins from Achyranthes bidentata Blume was developed. Methyl tert-butyl ether/n-butanol/acetonitrile/water (4:2:3:8, v/v/v/v) was selected for 20-hydroxyecdysone (compound 1), chikusetsusaponin IVa methyl ester (compound 4), 2'-glycan-11-keto-pigmented saponin V (compound 5), as well as a pair of isomers of 25S-inokosterone (compound 2) and 25R-inokosterone (compound 3), which were further purified by silver nitrate coordinated high-speed countercurrent chromatography. What is more, dichloromethane/methanol/isopropanol/water (6:6:1:4, v/v/v/v) was applied for calenduloside E (compound 6), 3β-[(O-β-d-glucuronopyranosyl)-oxy]-oleana-11,13-dien-28-oic acid (compound 7), zingibroside R1 (compound 8) and chikusetsusaponin IVa (compound 9). Adding Ag+ to the solvent system resulted in unique selectivity for 25R/25S isomers of inokosterone, which increased the complexing capability and stability of Ag+ coordinated 25S-inokosterone, as well as the α value between them. These results were further confirmed by the computational calculation of geometry optimization and frontier molecular orbitals assay. Comprehensive mass spectrometry and nuclear magnetic resonance analysis demonstrated the structures of the obtained compounds.

Codonopsis pilosula polysaccharides promote osteogenic differentiation and inhibit lipogenic differentiation of rat bone marrow stem cells by activating β-catenin

Aberrant bone marrow mesenchymal stem cell (BMSC) lineage differentiation leads to osteoporosis. Codonopsis pilosula polysaccharides (CPPs) have been widely used in traditional Chinese medicines, due to their multiple pharmacological actions. However, little is known regarding their effects on BMSC differentiation. This study aimed to identify the effects and mechanisms of CPPs on osteogenic and adipogenic differentiation in rat BMSCs. An osteoporosis model was established in Sprague-Dawley (SD) rats through bilateral ovariectomy (OVX), and be applied to observe the effect of CPPs on osteoporosis in vivo. The ability of CPPs to affect rBMSC proliferation was determined using the CCK-8 assay, and the osteogenic differentiation of rBMSCs measured by ALP and Alizarin Red S staining. The adipogenic differentiation of rBMSCs was measured by Oil Red O staining. The mRNA and protein levels related to osteogenesis and adipogenic differentiation of rBMSCs were measured using qRT-PCR and western blotting, respectively. Cellular immunofluorescence was used to detect cytokine expression and localisation in rBMSCs. We observed that CPPs ameliorated bone loss in OVX rats. CPPs considerably enhanced osteogenic differentiation by increasing ALP activity and the prevalence of mineralised nodules and promoting the mRNA and protein expression of osteogenic differentiation markers (RUNX2, COL I, ALP, and OPN). Furthermore, it inhibited the accumulation of lipid vesicles in the cytoplasm and the mRNA and protein expression levels of adipogenic differentiation markers (PPARγ and C/EBPα) in a concentration-dependent manner. Meanwhile, CPPs notably increased the mRNA and protein expression of β-catenin, the core protein of the Wnt/β-catenin signaling pathway, in a concentration-dependent manner. Adding DKK1, a mature inhibitor of the Wnt/β-catenin signaling pathway, partially suppressed CPP-stimulated β-catenin activation, and reversed the acceleration of osteogenic differentiation and the inhibition of lipogenic differentiation. Our observations demonstrated CPPs ameliorate bone loss in OVX rats in vivo, and favour osteogenic differentiation while inhibit adipogenic differentiation of rBMSCs in vitro. The findings suggested that CPPs could serve as functional foods for bone health, and have great potential for the prevention and treatment of osteoporosis.

Glycobiology in osteoclast differentiation and function

Glycans, either alone or in complex with glycan-binding proteins, are essential structures that can regulate cell biology by mediating protein stability or receptor dimerization under physiological and pathological conditions. Certain glycans are ligands for lectins, which are carbohydrate-specific receptors. Bone is a complex tissue that provides mechanical support for muscles and joints, and the regulation of bone mass in mammals is governed by complex interplay between bone-forming cells, called osteoblasts, and bone-resorbing cells, called osteoclasts. Bone erosion occurs when bone resorption notably exceeds bone formation. Osteoclasts may be activated during cancer, leading to a range of symptoms, including bone pain, fracture, and spinal cord compression. Our understanding of the role of protein glycosylation in cells and tissues involved in osteoclastogenesis suggests that glycosylation-based treatments can be used in the management of diseases. The aims of this review are to clarify the process of bone resorption and investigate the signaling pathways mediated by glycosylation and their roles in osteoclast biology. Moreover, we aim to outline how the lessons learned about these approaches are paving the way for future glycobiology-focused therapeutics.

A review focusing on the benefits of plant-derived polysaccharides for osteoarthritis

Osteoarthritis (OA) is a chronic joint disease characterized by progressive cartilage degeneration, which imposes a heavy physical and financial burden on the middle-aged and elderly population. As the pathogenesis of OA has not been fully elucidated, it is of great importance to develop targeted therapeutic or preventive medications. Traditional therapeutic drugs, such as non-steroidal anti-inflammatory drugs, steroids and opioids, have significant side effects, making the exploration for safe and effective alternative therapeutic drugs urgent. In recent years, many studies have reported the role of plant-derived polysaccharides in anti-inflammation, anti-oxidation, regulation of chondrocyte metabolism and proliferation, and cartilage protection, and have demonstrated their great potential in the treatment of OA. Therefore, by focusing on studies related to the intervention of plant-derived polysaccharides in OA, including in vivo and in vitro experiments, this review aimed to classify and summarize the existing research findings according to different mechanisms of action. In addition, reports on plant-derived polysaccharides as nanoparticles were also explored. Then, candidate monomers and theoretical bases were provided for the further development and application of novel drugs in the treatment of OA.

Structural characterization of a mannoglucan polysaccharide from Dendrobium huoshanense and evaluation of its osteogenesis promotion activities

Dendrobium huoshanense, a valuable traditional Chinese herb, is widely used to prolong life in China. Our study aims to characterize the structure and osteogenesis-promotion effects of a heteropolysaccharide component isolated from Dendrobium huoshanense (DHPW1). The structure of DHPW1 was characterized using gas chromatography-mass spectrometry and nuclear magnetic resonance, while its osteogenic activity was evaluated using MG-63 cells and zebrafish skulls. The results showed that the molecular weight of DHPW1 was 230 kDa and it was mainly composed of mannose and glucose. In addition, the DHPW1 backbone consisted of (1 → 4)-linked-β-D-Mannopyranosyl and (1 → 4)-linked-β-d-Glucopyranosyl. Furthermore, DHPW1 significantly increased ALP activity and mineralized nodule formation in MG-63 cells. DHPW1 in zebrafish skull models significantly enhanced the relative fluorescence intensity of bone mass and increased the degree of bone mineralization. These results suggested that the DHPW1 component in D. huoshanense has potential to promote osteogenesis.

Advances in Anti-Osteoporosis Polysaccharides Derived from Medicinal Herbs and Other Edible Substances

Osteoporosis is a common metabolic bone disease, and treatment is required for the prevention of low bone mass, deterioration of microstructural bone tissue, and fragility fractures. Osteoporosis therapy includes calcium, vitamin D, and drugs with antiresorptive or anabolic action on the bone. Therapy for osteoporosis does not include taking non-steroidal anti-inflammatory drugs (NSAID), but pain associated with osteoporotic fractures can be treated by taking non-steroidal anti-inflammatory drugs (NSAID). Recently, polysaccharides extracted from medicinal herbs and edible substances (PsMHES) have attracted attention on account of their safety and promising anti-osteoporosis effects, whereas a systematic review about their potential in anti-osteoporosis is vacant to date. Herein, we reviewed the recent progress of PsMHES with anti-osteoporosis activities, looking to introduce the advances in the various pharmacological mechanisms and targets involved in the anti-osteoporosis effects, extraction methods, main mechanism involved in Wnt/[Formula: see text]-catenin pathways and RANKL (Receptor Activator for NF[Formula: see text]B ligand or TNFSF25) pathways, and Structure-Activity Relationships (SAR) analysis of PsMHES. Typical herbs likeAchyranthes bidentate and Morinda officinalis used for the treatment of osteoporosis are introduced; their traditional uses in traditional Chinese medicine (TCM) are discussed in this paper as well. This review will help to the recognition of the value of PsMHES in anti-osteoporosis and provide guidance for the research and development of new anti-osteoporosis agents in clinic.

Compatibility of Achyranthes bidentata components in reducing inflammatory response through Arachidonic acid pathway for treatment of Osteoarthritis

Achyranthes bidentate is a common traditional Chinese medicine (TCM) used in treating osteoarthritis (OA). The compatibility between effective components has now become a breakthrough in understanding the mechanism of TCM. This study aimed at determining the optimal compatibility and possible mechanism of Achyranthes bidentate for OA treatment. Results showed that the adhesion score of the OA group is higher than NC group, and showed a trend of down-regulation in the intervention group. The CHI3L1 and IL-1β in joint fluid of the OA group was significantly increased compared to the sham operation group (NC group). Group G, I, and L exhibited significantly down-regulated CHI3L1, while groups C, F, I, K, and L exhibited reduced IL-1β. Joint adhesion, damage in cartilage, and synovial tissue was found in the OA model, cartilage tissue was found recovered in groups I, J, and L, and synovial tissue was recovered in group G, I, and L. Thus, group I and L were chosen for metabolite analysis, and indole-3-propionic acid was slightly up-regulated, while koeiginequinone A, prostaglandin H2, and 1-hydroxy-3-methoxy-10-methylacridonew were down-regulated in group I and L. According to functional analysis, the arachidonic acid (AA) metabolic pathway is enriched. Down-regulated expression of vital proteins in the AA metabolism pathway, such as PGE2 and COX2 in group I and L were verified. In conclusion, Hydroxyecdysone, Oleanolic acid, Achyranthes bidentata polysaccharide at a compatibility of 0.03-μg/mg, 2.0-μg/mg, 20.0-μg/mg or 0.03-μg/mg, 2.0-μg/mg, 10.0-μg/mg, respectively, may be the optimal compatibility of Achyranthes bidentate.

Saponin constituents of Achyranthes root

Achyranthes root is a crude drug used as diuretic, tonic and remedy for blood stasis. Characteristic oleanolic acid saponins with a dicarboxylic acid moiety have been isolated as one of the representative constituents of this crude drug. This review focuses on the triterpene saponin constituents, especially those with a characteristic dicarboxylic acid moiety, of A. bidentata and A. fauriei. Several groups isolated the saponins and different names were given to one compound in some cases. The names of the compounds are sorted out and the stereochemistry of the dicarboxylic acid moieties are summarized. HPLC analysis of the composition of the saponin constituents and the effect of processing and extraction conditions on the composition are reviewed. Biological activities of the saponin constituents are also summarized.

Benefits and mechanisms of polysaccharides from Chinese medicinal herbs for anti-osteoporosis therapy: A review

Osteoporosis is a systemic metabolic bone disease with an increasing incidence rate. Chinese medicinal herbs have a long history of treating bone diseases. Polysaccharides are an important category of phytochemicals in Chinese medicinal herbs, and their health benefits have increased the interest of the public. Numerous studies have indicated that polysaccharides exhibit anti-osteoporosis effects by balancing bone resorption and bone formation, but the detailed effects and mechanism have not been systematically summarized. We performed a comprehensive review of the literature to consolidate studies for the period 2000-2021 by conducting electronic searches on the PubMed, CNKI, VIP, and Wanfang databases. In total, polysaccharides from 19 kinds of Chinese medicinal herbs in 54 studies have shown bone homeostasis protective properties. In vivo and in vitro experiments have demonstrated that polysaccharides present properties in the treatment of postmenopausal osteoporosis, senile osteoporosis, and glucocorticoid-induced secondary osteoporosis, especially postmenopausal osteoporosis. Moreover, a number of signalling pathways, such as the Wnt/β-catenin signalling pathway, BMP/SMAD/RUNX2 signalling pathway, OPG/RANKL/RANK signalling pathway, apoptosis pathway, and transcription factors, are regulated by polysaccharides and participate in improving bone homeostasis. This review will provide a better understanding of the anti-osteoporotic effects of polysaccharides and the concomitant modulations of signalling pathways.

Research Progress on the Antiosteoarthritic Mechanism of Action of Natural Products

Background

Osteoarthritis (OA) is a clinical joint degenerative disease, the pathogenic factors of which include age, obesity, and mechanical injury. Its main pathological features include cartilage loss, narrowing of joint space, and osteophyte formation. At present, there are a variety of treatment methods for OA. Natural products, which are gradually being applied in the treatment of OA, are advantageous as they present with low toxicity and low costs and act on multiple targets.

Methods

The terms “natural products,” “osteoarthritis,” and “chondrocytes” were searched in PubMed to screen the related literature in the recent 10 years.

Results

We comprehensively introduced 62 published papers on 48 natural products involving 6, 3, 5, 12, 4, and 5 kinds of terpenoids, polysaccharides, polyphenols, flavonoids, alkaloids, and saponins, respectively (and others).

Conclusion

The mechanisms of their anti-OA action mainly involve reducing the production of inflammatory factors, reducing oxidative stress, regulating the metabolism of chondrocytes, promoting the proliferation of chondrocytes, or inhibiting chondrocyte apoptosis. This article summarizes the anti-OA activity of natural products in the last 10 years and provides candidate monomers for further study for use in OA treatment.

Astragalus polysaccharide attenuates LPS-related inflammatory osteolysis by suppressing osteoclastogenesis by reducing the MAPK signalling pathway

Bacterial products can stimulate inflammatory reaction and activate immune cells to enhance the production of inflammatory cytokines, and finally promote osteoclasts recruitment and activity, leading to bone destruction. Unfortunately, effective preventive and treatment measures for inflammatory osteolysis are limited and usually confuse the orthopedist. Astragalus polysaccharide (APS), the main extractive of Astragali Radix, has been widely used for treating inflammatory diseases. In the current study, in vitro and in vivo experimental results demonstrated that APS notably inhibited osteoclast formation and differentiation dose-dependently. Moreover, we found that APS down-regulated RANKL-related osteoclastogenesis and levels of osteoclast marker genes, such as NFATC1, TRAP, c-FOS and cathepsin K. Further underlying mechanism investigation revealed that APS attenuated activity of MAPK signalling pathways (eg ERK, JNK and p38) and ROS production induced by RANKL. Additionally, APS was also found to suppress LPS-related inflammatory osteolysis by decreasing inflammatory factors' production in vivo. Overall, our findings demonstrate that APS effectively down-regulates inflammatory osteolysis due to osteoclast differentiation and has the potential to become an effective treatment of the disorders associated with osteoclast.

Structural characterization and in vitro osteogenic activity of ABPB-4, a heteropolysaccharide from the rhizome of Achyranthes bidentata

Achyranthes bidentata is a species of flowering plant that is mainly distributed in China. The A. bidentata rhizome is a famous traditional Chinese medicine that has been widely used to treat lumbago, arthritis, and bone hyperplasia. In this work, A. bidentata rhizome was isolated and purified to obtain a pectic polysaccharide (ABPB-4). Chemical and spectral analyses showed that ABPB-4 had a main chain of →4)-α-d-GalpA-(1→ and →2,4)-α-l-Rhap-(1→, and the branch chains included →4)-β-d-Galp-(1→, →6)-β-d-Galp-(1→, →3,6)-β-d-Galp-(1→, →5)-α-l-Araf-(1→ and →3,5)-α-l-Araf-(1→, and it was terminated with α-l-Araf-(1→ and β-d-Galp-(1→. At concentrations of 0.01, 0.02, and 0.04 μmol/L, ABPB-4 significantly promotes the proliferation, differentiation, and mineralization of MC3T3-E1 cells in vitro, and it appreciably enhances the mRNA expression levels of osteogenic-related genes in these cells. Overall, the results reported herein indicate that ABPB-4 has outstanding osteogenic activity, and that it may be used as an anti-osteoporosis agent in the future.

Emerging Natural-Product-Based Treatments for the Management of Osteoarthritis

Osteoarthritis (OA) is a complex degenerative disease in which joint homeostasis is disrupted, leading to synovial inflammation, cartilage degradation, subchondral bone remodeling, and resulting in pain and joint disability. Yet, the development of new treatment strategies to restore the equilibrium of the osteoarthritic joint remains a challenge. Numerous studies have revealed that dietary components and/or natural products have anti-inflammatory, antioxidant, anti-bone-resorption, and anabolic potential and have received much attention toward the development of new therapeutic strategies for OA treatment. In the present review, we provide an overview of current and emerging natural-product-based research treatments for OA management by drawing attention to experimental, pre-clinical, and clinical models. Herein, we review current and emerging natural-product-based research treatments for OA management.

Bioactive Herbal Extracts of Traditional Chinese Medicine Applied with the Biomaterials: For the Current Applications and Advances in the Musculoskeletal System

Traditional Chinese medicine (TCM) has demonstrated superior therapeutic effect for musculoskeletal diseases for thousands of years. Recently, the herbal extracts of TCM have received rapid advances in musculoskeletal tissue engineering (MTE). A literature review collecting both English and Chinese references on bioactive herbal extracts of TCM in biomaterial-based approaches was performed. This review provides an up-to-date overview of application of TCMs in the field of MTE, involving regulation of multiple signaling pathways in osteogenesis, angiogenesis, anti-inflammation, and chondrogenesis. Meanwhile, we highlight the potential advantages of TCM, opening the possibility of its extensive application in MTE. Overall, the superiority of traditional Chinese medicine turns it into an attractive candidate for coupling with advanced additive manufacturing technology.

Network Pharmacology Approach to Uncover the Mechanism Governing the Effect of Simiao Powder on Knee Osteoarthritis

Objective

To explore the molecular mechanism of Simiao powder in the treatment of knee osteoarthritis.

Methods

Based on oral bioavailability and drug-likeness, the main active components of Simiao powder were screened using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). GeneCard, OMIM, DisGeNET, DrugBank, PharmGkb, and the Therapeutic Target Database were used to establish target databases for knee osteoarthritis. Cytoscape software was used to construct a visual interactive network diagram of “active ingredient - action target – disease.” The STRING database was used to construct a protein interaction network and analyze related protein interaction relationships. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) biological process enrichment analysis were performed on the core targets. Additionally, Discovery Studio software was used for molecular docking verification of active pharmaceutical ingredients and disease targets.

Results

Thirty-seven active components of Simiao powder were screened, including 106 common targets. The results of network analysis showed that the targets were mainly involved in regulating biological processes such as cell metabolism and apoptosis. Simiao powder components were predicted to exert their therapeutic effect on the AGE-RAGE signaling pathway in diabetic complications, IL-17 signaling pathway, TNF signaling pathway, Toll-like receptor signaling pathway, and HIF-1 signaling pathway. The molecular docking results showed that the active components of Simiao powder had a good match with the targets of IL1B, MMP9, CXCL8, MAPK8, JUN, IL6, MAPK1, EGF, VEGFA, AKT1, and PTGS2.

Conclusion

Simiao powder has multisystem, multicomponent, and multitarget characteristics in treating knee osteoarthritis. Its possible mechanism of action includes inhibiting the inflammatory response, regulating immune function, and resisting oxidative stress to control the occurrence and development of the disease. Quercetin, wogonin, kaempferol, beta-sitosterol, and other active ingredients may be the material basis for the treatment of knee osteoarthritis.

Chinese Herbal Medicines for Rheumatoid Arthritis: Text-Mining the Classical Literature for Potentially Effective Natural Products

Background

Rheumatoid arthritis (RA) is an autoimmune disease characterized by multijoint swelling, pain, and destruction of the synovial joints. Treatments are available but new therapies are still required. One source of new therapies is natural products, including herbs used in traditional medicines. In China and neighbouring countries, natural products have been used throughout recorded history and are still in use for RA and its symptoms. This study used text-mining of a database of classical Chinese medical books to identify candidates for future clinical and experimental investigations of therapeutics for RA.

Methods

The database Encyclopaedia of Traditional Chinese Medicine (Zhong Hua Yi Dian) includes the full texts of over 1,150 classical books. Eight traditional terms were searched. All citations were assessed for relevance to RA. Results and Conclusions. After removal of duplications, 3,174 citations were considered. After applying the exclusion and inclusion criteria, 548 citations of traditional formulas were included. These derived from 138 books written from 206 CE to 1948. These formulas included 5,018 ingredients (mean, 9 ingredients/formula) comprising 243 different natural products. When these text-mining results were compared to the 18 formulas recommended in a modern Chinese Medicine clinical practice guideline, 44% of the herbal formulas were the same. This suggests considerable continuity in the clinical application of these herbs between classical and modern Chinese medicine practice. Of the 15 herbs most frequently used as ingredients of the classical formulas, all have received research attention, and all have been reported to have anti-inflammatory effects. Two of these 15 herbs have already been developed into new anti-RA therapeutics—sinomenine from Sinomenium acutum (Thunb.) Rehd. & Wils and total glucosides of peony from Paeonia lactiflora Pall. Nevertheless, there remains considerable scope for further research. This text-mining approach was effective in identifying multiple natural product candidates for future research.

Network Pharmacology Approach to Uncover the Mechanism Governing the Effect of Radix Achyranthis Bidentatae on Osteoarthritis

BACKGROUND

This study used a network pharmacology approach to elucidate the molecular mechanism governing the effect of Radix Achyranthis Bidentatae (RAB) on osteoarthritis (OA).

METHODS

Based on oral bioavailability and drug-likeness, the main active components of RAB were screened via the Traditional Chinese Medicine Systems Pharmacology platform. The GeneCard, OMIM, PharmGkb, Therapeutic Targets database, and DrugBank database were used to establish a database of osteoarthritis targets. The interactive active network map of "ingredient-target" was constructed with Cytoscape software (Version 3.7.1). The protein-protein interaction network was constructed with the STRING database, and the related protein interaction relationship was analysed. GO biological function analysis and KEGG enrichment analysis for core targets were performed. Finally, docking of the active components with the core target was carried out.

RESULTS

Sixteen active components of RAB were obtained, and 63 potential targets for OA were identified. Network analysis results indicate that these targets are primarily involved in regulating biological processes, such as cell metabolism, apoptosis, and cell proliferation. Pathways involved in the treatment of osteoarthritis include virus-related signalling pathways, apoptosis signalling pathways, IL-17 signalling pathways, and PI3K/AKT signalling pathways.

CONCLUSION

RAB has the characteristics of being multi-system, multi-component and multi-target. Possible mechanisms of action for RAB include regulating the immune and inflammatory responses, reducing chondrocyte apoptosis, and protecting the joint synovial membrane and cartilage to control disease development. The active ingredients in RAB, such as sterols and flavonoids, exhibit strong potential as candidate drugs for the treatment of osteoarthritis.

Asperpyrone A attenuates RANKL-induced osteoclast formation through inhibiting NFATc1, Ca2+ signalling and oxidative stress

Imbalance of osteoblast and osteoclast in adult leads to a variety of bone-related diseases, including osteoporosis. Thus, suppressing the activity of osteoclastic bone resorption becomes the main therapeutic strategy for osteoporosis. Asperpyrone A is a natural compound isolated from Aspergillus niger with various biological activities of antitumour, antimicrobial and antioxidant. The present study was designed to investigate the effects of Asperpyrone A on osteoclastogenesis and to explore its underlining mechanism. We found that Asperpyrone A inhibited RANKL-induced osteoclastogenesis in a dose-dependent manner when the concentration reached 1 µm, and with no cytotoxicity until the concentration reached to 10 µm. In addition, Asperpyrone A down-regulated the mRNA and protein expression of NFATc1, c-fos and V-ATPase-d2, as well as the mRNA expression of TRAcP and Ctsk. Furthermore, Asperpyrone A strongly attenuated the RNAKL-induced intracellular Ca2+ oscillations and ROS (reactive oxygen species) production in the process of osteoclastogenesis and suppressed the activation of MAPK and NF-κB signalling pathways. Collectively, Asperpyrone A attenuates RANKL-induced osteoclast formation via suppressing NFATc1, Ca2+ signalling and oxidative stress, as well as MAPK and NF-κB signalling pathways, indicating that this compound may become a potential candidate drug for the prevention or treatment of osteoporosis.

Up-regulated CST5 inhibits bone resorption and activation of osteoclasts in rat models of osteoporosis via suppression of the NF-κB pathway

Here, we aim at exploring the effect of CST5 on bone resorption and activation of osteoclasts in osteoporosis (OP) rats through the NF‐κB pathway. Microarray analysis was used to screen the OP‐related differentially expressed genes. Osteoporosis was induced in rats by intragastric retinoic acid administration. The serum levels of tartrate‐resistant acid phosphatase (TRAP), bone alkaline phosphatase (BALP) and osteocalcin (OC) and the expression of CD61 on the surface of osteoclasts were examined. The number of osteoclasts and the number and area of resorption pits were detected. Besides, the pathological changes and bone mineral density in bone tissues of rats were assessed. Also, the relationship between CST5 and the NF‐κB pathway was identified through determining the expression of CST5, RANKL, RANK, OPG, p65 and IKB. Poorly expressed CST5 was indicated to affect the OP. CST5 elevation and inhibition of the NF‐κB pathway decreased serum levels of TRAP, BALP and OC and expression of CD61 in vivo and in vitro. In OP rats, CST5 overexpression increased trabecular bones and bone mineral density of bone tissues, but decreased trabecular separation, fat within the bone marrow cavities and the number of osteoclasts through inhibiting the NF‐κB pathway. In vivo experiments showed that CST5 elevation inhibited growth in number and area of osteoclastic resorption pits and restrained osteoclastic bone absorption by inhibiting the NF‐κB pathway. In summary, overexpression of CST5 suppresses the activation and bone resorption of osteoclasts by inhibiting the activation of the NF‐κB pathway.

Decreased fracture incidence with traditional Chinese medicine therapy in patients with osteoporosis: a nationwide population-based cohort study

BACKGROUND

There are no published studies regarding the efficacy of traditional Chinese medicine (TCM) for the prevention of osteoporotic fracture. Therefore, we conducted this nationwide, population-based cohort study to investigate the probable effect of TCM to decrease the fracture rate.

METHODS

We identified cases with osteoporosis and selected a comparison group that was frequency-matched according to sex, age (per 5 years), diagnosis year of osteoporosis, and index year. The difference between the two groups in the development of fracture was estimated using the Kaplan-Meier method and the log-rank test.

RESULTS

After inserting age, gender, urbanization level, and comorbidities into the Cox's proportional hazard model, patients who used TCM had a lower hazard ratio (HR) of fracture (adjusted HR: 0.47, 95% CI: 0.37-0.59) compared to the non-TCM user group. The Kaplan-Meier curves showed that osteoporosis patients who used TCM had a lower incidence of fracture events than those who did not (p < 0.00001). Our study also demonstrated that the longer the TCM use, the lesser the fracture rate.

CONCLUSION

Our study showed that TCM might have a positive impact on the prevention of osteoporotic fracture.

A liquid chromatography-tandem mass spectrometry approach for study the tissue distributions of five components of crude and salt-processed Radix Achyranthes in rats

This study developed a robust and reliable approach using liquid chromatography- tandem mass spectrometry for the simultaneous determination of five saponins in rat tissues: β-ecdysterone, chikusetsusaponin IV, ginsenoside Ro, 25S-inokosterone and chikusetsusaponin IVa. This is the first report on a comparative tissue distribution study of crude and salt-processed Radix Achyranthes in rats. After one-step protein precipitation by acetonitrile, the tissue samples were sent to LC-MS/MS for multiple reaction monitoring. The retention times of the five saponins and internal standard were 1.77, 3.14, 3.01, 1.83, 3.26 and 4.77 min. The standard curves showed good linear regression (r²  > 0.9991) in the range of 10.3-1562.5 ng/mL. The intra- and inter-day accuracy and precision were within 15% of the nominal concentration. The recoveries of the five saponins were 92.0-99.9%. Finally, this approach was successfully applied to tissue distribution analysis of the five saponins after oral administration of crude and salt-processed Radix Achyranthes in rats. The largest concentration of the five saponins was observed in kidney after salt-processing, which indicated that processing could enhance the bioavailability.

Madecassoside inhibits estrogen deficiency-induced osteoporosis by suppressing RANKL-induced osteoclastogenesis

Osteoporosis is the most common osteolytic disease characterized by excessive osteoclast formation and resultant bone loss, which afflicts millions of patients around the world. Madecassoside (MA), isolated from Centella asiatica, was reported to have anti-inflammatory and antioxidant activities, but its role in osteoporosis treatment has not yet been confirmed. In our study, MA was found to have an inhibitory effect on the RANKL-induced formation and function of OCs in a dose-dependent manner without cytotoxicity. These effects were attributed to its ability to suppress the activity of two transcription factors (NFATc1 and c-Fos) indispensable for osteoclast formation, followed by inhibition of the expression of bone resorption-related genes and proteins (Acp5/TRAcP, CTSK, ATP6V0D2/V-ATPase-d2, and integrin β3). Furthermore, we examined the underlying mechanisms and found that MA represses osteoclastogenesis by blocking Ca2+ oscillations and the NF-κB and MAPK pathways. In addition, the therapeutic effect of MA on preventing bone loss in vivo was further confirmed in an ovariectomized mouse model. Therefore, considering its ability to inhibit RANKL-mediated osteoclastogenesis and the underlying mechanisms, MA might be a potential candidate for treating osteolytic bone diseases.