Effects of medicinal herb salvia miltiorrhiza on osteoblastic cells in vitro

Structure revision and absolute configuration of 5,7-diepi-2α-hydroxyoplopanone and anti-osteoporotic activities of sesquiterpenoids from the rhizomes of Homalomena pendula

Five sesquiterpenoids including 2α-hydroxyoplopanone (1), oplopanone (2), 1β,4β,6α-trihydroxy-eudesmane (3), 1β,4β,7α-trihydroxy-eudesmane (4) and bullatantriol (5) were isolated from Homalomena pendula. The structure of the previously reported compound, 5,7-diepi-2α-hydroxyoplopanone (1a), has been revised to 1 by the spectroscopic evidences (1D-/2D-NMR, IR, UV and HRESIMS) and by comparison between experimental and theoretical NMR data using DP4+ protocol. Furthermore, the absolute configuration of 1 was unambiguously assigned by ECD experiments. Compounds 2 and 4 displayed a potent ability to stimulate osteogenic differentiation of MC3T3-E1 cells at 4 µg/mL (by 123.74% and 131.07%, respectively) and 20 µg/mL (by 112.45% and 126.41%, respectively) whilst 3 and 5 did not show any activities. At 20 µg/mL, 4 and 5 significantly promoted the mineralization of MC3T3-E1 cells with values of 112.95% and 116.37%, respectively, whereas 2 and 3 were inactive. The results indicated that 4 could be an excellent component for anti-osteoporosis studies from the rhizomes of H. pendula.

A review on therapeutic mechanism of medicinal plants against osteoporosis: effects of phytoconstituents

Osteoporosis is a metabolic bone disorder that over time results in bone loss and raises the risk of fracture. The condition is frequently silent and only becomes apparent when fractures develop. Osteoporosis is treated with pharmacotherapy as well as non-pharmacological therapies such as mineral supplements, lifestyle changes, and exercise routines. Herbal medicine is frequently used in clinical procedures because of its low risk of adverse effects and cost-effective therapeutic results. In the current review, we have used a thorough strategy to identify some known medicinal plants with anti-osteoporosis capabilities, their origin, active ingredients, and pharmacological information. Furthermore, several signaling pathways, such as the apoptotic pathway, transcription factors, the Wnt/-catenin signaling pathway, and others, are regulated by bioactive components and help to improve bone homeostasis. This review will provide a better understanding of the anti-osteoporotic effects of bioactive components and the concomitant modulations of signaling pathways.

Synthetic Calcium-Phosphate Materials for Bone Grafting

Synthetic bone grafting materials play a significant role in various medical applications involving bone regeneration and repair. Their ability to mimic the properties of natural bone and promote the healing process has contributed to their growing relevance. While calcium-phosphates and their composites with various polymers and biopolymers are widely used in clinical and experimental research, the diverse range of available polymer-based materials poses challenges in selecting the most suitable grafts for successful bone repair. This review aims to address the fundamental issues of bone biology and regeneration while providing a clear perspective on the principles guiding the development of synthetic materials. In this study, we delve into the basic principles underlying the creation of synthetic bone composites and explore the mechanisms of formation for biologically important complexes and structures associated with the various constituent parts of these materials. Additionally, we offer comprehensive information on the application of biologically active substances to enhance the properties and bioactivity of synthetic bone grafting materials. By presenting these insights, our review enables a deeper understanding of the regeneration processes facilitated by the application of synthetic bone composites.

Volatile Constituents and Anti-Osteoporotic Activity of the n-Hexane Extract From Homalomena gigantea Rhizome

This study analyzed the chemical composition and anti-osteoporosis activity of the n-hexane extract of Homalomena gigantea rhizome. Sixty compounds, representing 92.0% of the extract, were identified by gas chromatography-mass spectrometry. Linalool (15.3%), oplopanone (9.8%), ( Ε)-α-atlantone (5.6%), khusinol acetate (5.4%), bullatantriol (4.3%), and β-sitosterol (3.8%) were the main constituents. The anti-osteoporotic activity of the n-hexane extract was determined by measuring alkaline phosphatase (ALP) activity, collagen content, and the mineralization of MC3T3-E1 cells. At concentrations of 4.0 and 20.0 µg/mL, the n-hexane extract increased ALP activity by 8.2% and 23.7%, and increased collagen secretion by MC3T3-E1 cells by 114.9% and 112.4%, respectively. At 4 µg/mL, the extract significantly promoted the mineralization of MC3T3-E1 cells by as much as 133.2% compared to the negative control. These results suggested that H. gigantea rhizome contains a natural anti-osteoporotic compound.

Evolving Roles of Natural Terpenoids From Traditional Chinese Medicine in the Treatment of Osteoporosis

Osteoporosis (OP) is a systemic metabolic skeletal disease which can lead to reduction in bone mass and increased risk of bone fracture due to the microstructural degradation. Traditional Chinese medicine (TCM) has been applied in the prevention and treatment of osteoporosis for a long time. Terpenoids, a class of natural products that are rich in TCM, have been widely studied for their therapeutic efficacy on bone resorption, osteogenesis, and concomitant inflammation. Terpenoids can be classified in four categories by structures, monoterpenoids, sesquiterpenoids, diterpenoids, and triterpenoids. In this review, we comprehensively summarize all the currently known TCM-derived terpenoids in the treatment of OP. In addition, we discuss the possible mechanistic-of-actions of all four category terpenoids in anti-OP and assess their therapeutic potential for OP treatment.

Protocatechuic acid attenuates anterior cruciate ligament transection-induced osteoarthritis by suppressing osteoclastogenesis

Osteoarthritis (OA) is related to over-proliferation or differentiation of osteoclasts. Although protocatechuic acid (PCA) has been identified to inhibit osteoclast differentiation and stimulate apoptosis in mature osteoclasts, whether it can relieve OA is still unknown. The present study aimed to investigate the effect of PCA on anterior cruciate ligament transection (ACLT)-induced OA and the potential mechanisms of action behind this effect. ACLT was performed on rats, which were then treated with or without PCA. C-terminal telopeptide of type I collagen (CTX-I) and CTX-II were tested in knee joint protein extracts by ELISA. Damage to cartilage was evaluated using Safranin-O/Fast Green staining. Osteoclast-related gene and protein expression was assessed through reverse transcription-quantitative PCR and western blotting. Tartrate-resistant acid phosphatase (TRAP) staining and functional bone resorption pit assays were performed using RAW264.7 murine macrophage cells to determine the effects of PCA on osteoclastic formation and function, respectively, in vitro. Finally, the activity of osteoclastogenesis-related signaling pathways was evaluated by western blotting. Levels of CTX-II were relatively decreased and Safranin-O/fast green staining indicated milder changes in the articular cartilage in the PCA treatment group. PCA downregulated osteoclast specific markers and suppressed receptor activator of nuclear factor-κB ligand-induced formation of TRAP-positive multinucleated cells, bone-resorption and pit formation. Mitogen-activated protein kinase (MAPK) and Akt signaling as well as the downstream factors, were downregulated by PCA. In conclusion, the present study demonstrated that PCA attenuated ACLT-induced OA by suppressing osteoclastogenesis by inhibiting the MAPK, ATK and NF-κB signaling pathways.

Ganoderma lucidum, a promising agent possessing antioxidant and anti-inflammatory effects for treating calvarial defects with graft application in rats

Purpose:

Ganoderma lucidum, a kind of mushroom used for its antioxidant, anti-inflammatory, and immunomodulatory activities, was investigated in the present study for its possible healing effect on calvarial defects with bone grafts.

Methods:

Wistar male rats (n = 30) were divided into 3 groups: 1) the control (defect) group (n = 10), 2) defect and graft group (n = 10), and 3) defect, graft, and G. lucidum treated group (n = 10). The G. lucidum was administered to the rats at 20 mL/kg per day via gastric lavage.

Results:

In the defect and graft group, osteonectin positive expression was observed in osteoblast and osteocyte cells at the periphery of the small bone trabeculae within the graft area. In the defect, graft, and G. lucidum treated group, osteonectin expression was positive in the osteoblast and osteocyte cells and positive osteonectin expression in new bone trabeculae. The expression of matrix metalloproteinase-9 (MMP-9) was positive in the inflammatory cells, fibroblast cells, and degenerated collagen fibril areas within the defect area.

Conclusion:

This study shows that, with its antioxidant and anti-inflammatory properties, G. Lucidum is an important factor in the treatment of calvarial bone defects.

Therapeutic Anabolic and Anticatabolic Benefits of Natural Chinese Medicines for the Treatment of Osteoporosis

Osteoporosis is a bone disease characterized by increasing osseous fragility and fracture due to the reduced bone mass and microstructural degradation. Primary pharmacological strategies for the treatment of osteoporosis, hormone replacement treatment (HRT), and alendronate therapies may produce adverse side-effects and may not be recommended for long-term usage. Some classic and bone-specific natural Chinese medicine are very popularly used to treat osteoporosis and bone fracture effectively in clinical with their potential value in bone growth and development, but with few adverse side-effects. Current evidence suggests that the treatments appear to improve bone metabolism and attenuate the osteoporotic imbalance between bone formation and bone resorption at a cellular level by promoting osteoblast activity and inhibiting the effects of osteoclasts. The valuable therapies might, therefore, provide an effective and safer alternative to primary pharmacological strategies. Therefore, the purpose of this article is to comprehensively review these classic and bone-specific drugs in natural Chinese medicines for the treatment of osteoporosis that had been deeply and definitely studied and reported with both bone formation and antiresorption effects, including Gynochthodes officinalis (F.C.How) Razafim. & B.Bremer (syn. Morinda officinalis F.C.How), Curculigo orchioides Gaertn., Psoralea corylifolia (L.) Medik Eucommia ulmoides Oliv., Dipsacus inermis Wall. (syn. Dipsacus asperoides C.Y.Cheng & T.M.Ai), Cibotium barometz (L.) J. Sm., Velvet Antler, Cistanche deserticola Ma, Cuscuta chinensis Lam., Cnidium monnieri (L.) Cusson, Epimedium brevicornum Maxim, Pueraria montana (Lour.) Merr. and Salvia miltiorrhiza Bunge., thus providing evidence for the potential use of alternative Chinese medicine therapies to effectively treat osteoporosis.

KLF2 regulates osteoblast differentiation by targeting of Runx2

Osteoblast differentiation plays a critical role in bone formation and maintaining balance in bone remodeling. Runt-related transcription factor 2 (Runx2) is a central transcription factor regulating osteoblast differentiation and promoting bone mineralization. Until now, the molecular regulatory basis and especially the gene regulatory network of osteogenic differentiation have been unclear. Krüppel-like factor 2 (KLF2) is a zinc finger structure and DNA-binding transcription factor. The current study aimed to investigate the physiological function of KLF2 in osteoblast differentiation. Our results indicate that KLF2 is expressed in pre-osteoblast MC3T3-E1 cells and primary osteoblasts. Interestingly, KLF2 expression is increased in osteoblasts during the osteoblastic differentiation process. Overexpression of KLF2 in MC3T3-E1 cells promoted the expression of the osteoblastic differentiation marker genes Alp, Osx, and Ocn, and stimulated mineralization by increasing Runx2 expression at both the mRNA and protein levels. In contrast, knockdown of KLF2 produced the opposite effects. Importantly, we found that KLF2 could physically interact with Runx2. KLF2 promoted osteoblast differentiation by regulating Runx2 and physically interacting with Runx2. Taken together, the findings of this study identify KLF2 as a novel regulator of osteoblast differentiation. Our findings suggest that KLF2 might be a new therapeutic target for bone disease.

Chinese single herbs and active ingredients for postmenopausal osteoporosis: From preclinical evidence to action mechanism

Postmenopausal osteoporosis is a systemic metabolic skeletal disease generally ascribable to a dearth of estrogen. Whether traditional Chinese medicine is effective in management of postmenopausal osteoporosis remains unclear. This article reviews the experimental evidence of both in vitro and in vivo preclinical studies with the theme of the application of Chinese single herbs and active ingredients in postmenopausal osteoporosis. It includes three single herbs (Herba Epimedium, Rhizoma Drynariae, and Salvia miltiorrhiza) and eight active ingredients (saikosaponins, linarin, echinacoside, sweroside, psoralen, poncirin, vanillic acid, and osthole). The experimental studies indicated their potential use as treatment for postmenopausal osteoporosis and investigated the underlying mechanisms including osteoprotegerin/receptor activator of nuclear factor κB ligand (OPG/RANKL), extracellular-signal-regulated kinase/c-Jun N terminal kinase/mitogen-activated protein kinase (ERK/JNK/MAPK), estrogen receptor (ER), bone morphogenetic protein (BMP), transforming growth factor (TGF)-β, Wnt/β-catenin, and Notch signaling pathways. This review contributes to a better understanding of traditional Chinese medicine and provides useful information for the development of more effective anti-osteoporosis drugs.

Effect of herbal extracts on bone regeneration in a rat calvaria defect model and screening system

Objectives

The aim of this study was to evaluate the effects of herbal extracts on bone regeneration. Two known samples were screened.

Materials and Methods

We previously established a rat calvaria defect model using a combination of collagen scaffold and herbal extracts. An 8 mm diameter trephine bur with a low-speed dental hand piece was used to create a circular calvaria defect. The experimental group was divided into 4 classifications: control, collagen matrix, Danshen with collagen, and Ge Gan with collagen. Animals in each group were sacrificed at 4, 6, 8, and 10 weeks after surgery, and bone regeneration ability was evaluated by histological examination.

Results

Results revealed that both Danshen and Ge Gan extracts increased bone formation activity when used with collagen matrix. All groups showed almost the same histological findings until 6 weeks. However, after 6 weeks, bone formation activity proceeded differently in each group. In the experimental groups, new bone formation activity was found continuously up to 10 weeks. In the Danshen and Ge Gan groups, grafted materials were still present until 10 weeks after treatment, as evidenced by foreign body reactions showing multinucleated giant cells in chronic inflammatory vascular connective tissue.

Conclusion

Histological analyses showed that Danshen and Ge Gan extractions increased bone formation activity when used in conjunction with collagen matrix.

Muscone exerts protective roles on alcohol-induced osteonecrosis of the femoral head

Long-term alcohol abuse causes musculoskeletal disorders, among of which, alcohol-induced osteonecrosis of the femoral head (ONFH) is of concern due to its significant and severe complications. A variety of methods have been attempted to prevent alcohol-induced ONFH, and monomers extracted from Chinese herbs might benefit the disease profoundly. In the current study, muscone, the main ingredient of musk, was used to prevent alcohol-induced ONFH. In vitro, ethanol was used to affect the potential of osteogenesis and proliferation of human bone mesenchymal stem cells (hBMSCs), and beneficial role of muscone was investigated on hBMSCs. In vivo, following the establishment of alcohol-induced ONFH, muscone was employed to treat the diseased rats, which were analyzed by micro-CT scanning and a series of histologic staining. As a result, we found ethanol could significantly suppress osteogenic differentiation of hBMSCs, while muscone held the potential to promote ALP activity and mRNA expressions of COL1 and OCN under ethanol treatment. Meanwhile, imaging analysis revealed muscone could restore BV/TV ratio and bone mineral density of the necrotic femoral head, and the protective role of muscone on alcohol-induced ONFH was further confirmed by histologic examinations. Our study confirmed the protective effect of muscone against alcohol-induced ONFH both in vitro and in vivo. Therefore, muscone may be considered as a valuable therapeutic natural drug for alcohol-induced ONFH in humans.

The role of kaempferol-induced autophagy on differentiation and mineralization of osteoblastic MC3T3-E1 cells

Background

Kaempferol, a kind of flavonol, has been reported to possess various osteogenic biological activities, such as inhibiting bone resorption of osteoclasts and promoting the differentiation and mineralization of preosteoblasts. However, the precise cellular mechanism of action of kaempferol in osteogenesis is elusive.

Autophagy is a major intracellular degradation system, which plays an important role in cell growth, survival, differentiation and homeostasis in mammals. Recent studies showed that autophagy appeared to be involved in the degradation of osteoclasts, osteoblasts and osteocytes, potentially pointing to a new pathogenic mechanism of bone homeostasis and bone marrow disease. The potential correlation between autophagy, osteogenesis and flavonoids is unclear.

Methods

The present study verified that kaempferol promoted osteogenic differentiation and mineralization and that it elevated osteogenic gene expression based on alkaline phosphatase (ALP) activity, alizarin red staining and quantitative PCR. And then we found that kaempferol induced autophagy by acridine orange (AO) and monodansylcadaverine (MDC) staining and autophagy-related protein expression. The correlation between kaempferol-induced autophagy and the osteogenic process was confirmed by the autophagy inhibitor 3-methyladenine (3-MA).

Results

Kaempferol promoted the proliferation, differentiation and mineralization of osteoblasts at a concentration of 10 μM. Kaempferol showed cytotoxic properties at concentrations above 50 μM. Concentrations above 10 μM decreased ALP activity, whereas those up to 10 μM increased ALP activity. Kaempferol at concentrations up to 10 μM also increased the expression of the osteoblast- activated factors RUNX-2, osterix, BMP-2 and collagen I according to RT-PCR analyses. 10 μM or less, the higher of the concentration and over time, kaempferol promoted the activity of osteoblasts. Kaempferol induced autophagy. It also increased the expression of the autophagy-related factors beclin-1, SQSTM1/p62 and the conversion of LC3-II from LC3-I. The application of 3-MA decreased the activity of ALP and the autophagy induced by kaempferol. In the RT-PCR analysis, the expression of RUNX-2, osterix, BMP-2 and collagen I was decreased.

Conclusion

The present study showed that kaempferol stimulated the osteogenic differentiation of cultured osteoblasts by inducing autophagy.

Natural Products from Chinese Medicines with Potential Benefits to Bone Health

Osteoporosis is a progressive, systemic bone disorder characterized by loss of bone mass and microstructure, leading to reduced bone strength and increased risk of fracture. It is often associated with reduced quality of life and other medical complications. The disease is common in the aging population, particularly among postmenopausal women and patients who receive long-term steroidal therapy. Given the rapid growth of the aging population, increasing life expectancy, the prevalence of bone loss, and financial burden to the healthcare system and individuals, demand for new therapeutic agents and nutritional supplements for the management and promotion of bone health is pressing. With the advent of global interest in complementary and alternative medicine and natural products, Chinese medicine serves as a viable source to offer benefits for the improvement and maintenance of bone health. This review summarizes the scientific information obtained from recent literatures on the chemical ingredients of Chinese medicinal plants that have been reported to possess osteoprotective and related properties in cell-based and/or animal models. Some of these natural products (or their derivatives) may become promising leads for development into dietary supplements or therapeutic drugs.

Salvia miltiorrhiza: an ancient Chinese herbal medicine as a source for anti-osteoporotic drugs

ETHNOPHARMACOLOGICAL RELEVANCE

Red sage (Salvia miltiorrhiza Bunge), also known as Danshen in Chinese, has been used historically and is currently exploited in combination with other herbs to treat skeletal diseases in traditional Chinese medicine (TCM). With the advance of modern analytical technology, a multitude of bone-targeting, pharmaceutically active, compounds has been isolated and characterized from various sources of TCM including those produced in Salvia miltiorrhiza root. The aim of the review is to provide a comprehensive overview about the historical TCM interpretation of the action of Salvia miltiorrhiza in osteoporosis, its use clinical trials, its main phytochemical constituents, and its action on bone-resorptive and bone formation-stimulating mechanisms in in vitro and in vivo studies.

MATERIALS AND METHODS

Literature sources used were Pubmed, CNKI.net, Cqvip.com, PubChem, and the Web of Science. For the inquiry, keywords such as Salvia, danshen, osteoporosis, bone, osteoclast and osteoblast were used in various combinations. About 130 research papers and reviews were consulted.

RESULTS

In TCM, the anti-osteopororotic effect of Salvia miltiorrhiza is ascribed to its action on liver and blood stasis as main therapeutic targets defining osteoporosis. 36 clinical trials were identified which used Salvia miltiorrhiza in combination with other herbs and components to treat post-menopausal, senile, and secondary osteoporosis. On average the trials were characterized by high efficacy (>80%) and low toxicity problems. However, various limitations such as small patient samples, short treatment duration, frequent lack of detailed numerical data, and no clear endpoints must be taken into consideration. To date, more than 100 individual compounds have been isolated from this plant and tested in various animal models and biochemical assays. Compounds display anti-resorptive and bone formation-stimulating features targeting different pathways in the bone remodeling cycle. Pathways affected include the activation of osteoblasts, the modulation of osteoclastogenesis, and the inhibition of collagen degradation by cathepsin K.

CONCLUSIONS

The inclusion of Salvia miltiorrhiza in more than 30% of all herbal clinical trials successfully targeting osteoporosis has stimulated significant interest in the identification and characterization of individual constituents of this herb. The review highlights the anti-osteoporotic potential of Salvia miltiorrhiza in clinical applications and the potential of the herb to provide potent compounds targeting specific pathways in bone resorption and bone formation.

Effects of 6-Hydroxyflavone on Osteoblast Differentiation in MC3T3-E1 Cells

Osteoblast differentiation plays an essential role in bone integrity. Isoflavones and some flavonoids are reported to have osteogenic activity and potentially possess the ability to treat osteoporosis. However, limited information concerning the osteogenic characteristics of hydroxyflavones is available. This study investigates the effects of various hydroxyflavones on osteoblast differentiation in MC3T3-E1 cells. The results showed that 6-hydroxyflavone (6-OH-F) and 7-hydroxyflavone (7-OH-F) stimulated ALP activity. However, baicalein and luteolin inhibited ALP activity and flavone showed no effect. Up to 50 μM of each compound was used for cytotoxic effects study; flavone, 6-OH-F, and 7-OH-F had no cytotoxicity on MC3T3-E1 cells. Moreover, 6-OH-F activated AKT and serine/threonine kinases (also known as protein kinase B or PKB), extracellular signal-regulated kinases (ERK 1/2), and the c-Jun N-terminal kinase (JNK) signaling pathways. On the other hand, 7-OH-F promoted osteoblast differentiation mainly by activating ERK 1/ 2 signaling pathways. Finally, after 5 weeks of 6-OH-F induction, MC3T3-E1 cells showed a significant increase in the calcein staining intensity relative to merely visible mineralization observed in cells cultured in the osteogenic medium only. These results suggested that 6-OH-F could activate AKT, ERK 1/2, and JNK signaling pathways to effectively promote osteoblastic differentiation.