Curculigoside improves osteogenesis of human amniotic fluid-derived stem cells

Targeting Wnt signaling pathway with small-molecule therapeutics for treating osteoporosis

Small molecules are emerging as potential candidates for treating osteoporosis by activating canonical Wnt signaling. These candidates work either by inhibiting DKK-1, sclerostin, SFRP-1, NOTUM, and S1P lyase or by preventing β-catenin degradation through inhibition of GSK-3β, or by targeting Dvl-CXXC5 and axin/β-catenin interactions. While many of these anti-osteoporotic small molecules are in preclinical development, the paucity of FDA-approved small molecules, or promising candidates, that have progressed to clinical trials for treating bone disorders through this mechanism poses a challenge. Despite advancements in computer-aided drug design, it is rarely employed for designing Wnt signaling activators to treat osteoporosis, and high-throughput screen (HTS) remains the primary method for discovering initial hits. Acknowledging the promising therapeutic potential of these compounds in addressing bone diseases, this review underscores the need for further mechanistic elucidation to enhance our understanding of their applications. Additionally, caution must be exercised in the design of small molecule-based Wnt activators due to their association with oncological risks.

Extract of Curculigo capitulata Ameliorates Postmenopausal Osteoporosis by Promoting Osteoblast Proliferation and Differentiation

Postmenopausal osteoporosis (PMOP) is a bone disease characterized by bone thinning and an increased risk of fractures due to estrogen deficiency. Current PMOP therapies often result in adverse side effects. The traditional medicinal plant Curculigo capitulata is commonly used to strengthen bones and support kidney function, but its role in treating PMOP is not well understood. This study aims to investigate the therapeutic effects of the total extract of Curculigo capitulata (Eocc) on PMOP and to explore the underlying mechanisms. The major components of the extract were identified using HPLC. Transcriptomics was employed to predict potential targets. An osteogenic differentiation model of MC3T3-E1 cells was used in vitro. The osteogenic potential of the Eocc was assessed through CCK-8 cell viability assays, alkaline phosphatase (ALP) staining, Alizarin Red staining, Western blotting, and qPCR. MCF-7 and HEK-293 cells were utilized to evaluate the estrogen-like activity of Eocc. Apoptosis rates were detected by flow cytometry. In vivo, a bilateral ovariectomized mouse model of PMOP was used to further validate the in vitro findings through histopathological analysis and WB results. The results demonstrated that the Eocc promoted the proliferation of MC3T3-E1 cells, increased ALP activity, and stimulated the formation of osteogenic mineralized nodules. It also upregulated the expression of osteogenic markers (Runx2, OCN, OPN, and BSP) at both the protein and mRNA levels. The Eocc induced the activation of ERα both in vitro and in vivo, initiating the Src/PI3K/AKT signaling pathway, leading to the phosphorylation of GSK3β and subsequent osteogenesis. The activation of this pathway also stimulated the phosphorylation of mTOR and p70S6K while downregulating cleaved caspase-3 and caspase-9. Additionally, the Eocc reduced apoptosis during osteogenic differentiation and promoted cell proliferation. These findings suggest that the Eocc facilitates osteoblast proliferation and differentiation, improving bone integrity in PMOP mice, and may represent a promising therapeutic candidate for managing PMOP.

Insight of Chinese Herbal Medicine in Treating Osteoporosis: Achievements from 2013 to 2023

Osteoporosis is the most common bone metabolic disease, and it is becoming increasingly common as the global population ages. Osteoporosis and its complications, such as fractures and pain, negatively affect patient quality of life and easily lead to disability, placing enormous burdens on society. Although several anti-osteoporosis drugs are currently available, many adverse reactions have been observed during the long-term application of these drugs. Therefore, safer and more useful medications are urgently needed to replace those currently available. Chinese herbal medicine has been extensively used to treat osteoporosis, and the current literature confirms that such medicines have anti-osteoporosis effects, are safe, and have minimal side effects. Thus, Chinese herbal medicines are natural alternatives to pharmaceutical approaches to treating osteoporosis, and these medicines must be further developed and utilized. In this article, we review the mechanisms underlying the anti-osteoporosis effects of single herbal extracts and traditional Chinese medicine (TCM) formulas that have been elucidated since 2013, providing key evidence and support for future research on the anti-osteoporosis effects of Chinese herbal medicines. In addition, due to the complexity of the ingredients in Chinese herbal medicine, more thorough investigations are needed to determine the specific ingredients that are effective in osteoporosis treatment. Therefore, identifying the effective ingredients of Chinese herbal medicines will be a necessary focus in laboratory research and clinical application.

Curculigoside inhibits osteoarthritis <em>via</em> the regulation of NLRP3 pathway

Osteoarthritis (OA) is characterized by degenerative articular cartilage. Nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) plays an important role in inflammation. This study aims to investigate whether protective effects of curculigoside on OA are medicated by the regulation of NLRP3 pathway. Destabilization of the medial meniscus (DMM) was performed to build an OA mouse model. After surgery, OA mice were treated with curculigoside. Immunohistochemistry was conducted to evaluate OA cartilage. In addition, human chondrocytes were isolated and treated with curculigoside. The mRNA and protein expression of iNOS, MMP-9, NLRP3 was detected by PCR and Western blot analysis. Curculigoside inhibited mRNA and protein levels of iNOS and MMP-9 induced by DMM surgery in a dose-dependent manner. Furthermore, the expression of NLRP3, NF-κB and PKR was downregulated after curculigoside administration. Moreover, curculigoside reversed the effects of IL-1β on MMP-9, iNOS and type II collagen expression at mRNA and protein levels in human chondrocytes in a dose-dependent manner. In conclusion, curculigoside exhibits beneficial effect on cartilage via the inhibition of NLRP3 pathway.

Role of Traditional Chinese Medicine in Bone Regeneration and Osteoporosis

According to World Health Organization (WHO), osteoporosis is a systematic bone disability marked by reduced bone mass and microarchitectural degeneration of osseous cells, which leads to increased bones feebleness and fractures vulnerability. It is a polygenetic, physiological bone deformity that frequently leads to osteoporotic fractures and raises the risk of fractures in minimal trauma. Additionally, the molecular changes that cause osteoporosis are linked to decreased fracture repair and delayed bone regeneration. Bones have the ability to regenerate as part of the healing mechanism after an accident or trauma, including musculoskeletal growth and ongoing remodeling throughout adulthood. The principal treatment approaches for bone loss illnesses, such as osteoporosis, are hormone replacement therapy (HRT) and bisphosphonates. In this review, we searched literature regarding the Traditional Chinese medicines (TCM) in osteoporosis and bone regeneration. The literature results are summarized in this review for osteoporosis and bone regeneration. Traditional Chinese medicines (TCM) have grown in popularity as a result of its success in curing ailments while causing minimal adverse effects. Natural Chinese medicine has already been utilized to cure various types of orthopedic illnesses, notably osteoporosis, bone fractures and rheumatism with great success. TCM is a discipline of conventional remedy that encompasses herbal medication, massage (tui na), acupuncture, food, and exercise (qigong) therapy. It is based on more than 2,500 years of Chinese healthcare profession. This article serves as a comprehensive review summarizing the osteoporosis, bone regeneration and the traditional Chinese medicines used since ancient times for the management of osteoporosis and bone regeneration.

Wnt signaling activation: targets and therapeutic opportunities for stem cell therapy and regenerative medicine

Wnt proteins are secreted morphogens that play critical roles in embryonic development, stem cell proliferation, self-renewal, tissue regeneration and remodeling in adults. While aberrant Wnt signaling contributes to diseases such as cancer, activation of Wnt/β-catenin signaling is a target of interest in stem cell therapy and regenerative medicine. Recent high throughput screenings from chemical and biological libraries, combined with improved gene expression reporter assays of Wnt/β-catenin activation together with rational drug design, led to the development of a myriad of Wnt activators, with different mechanisms of actions. Among them, Wnt mimics, antibodies targeting Wnt inhibitors, glycogen-synthase-3β inhibitors, and indirubins and other natural product derivatives are emerging modalities to treat bone, neurodegenerative, eye, and metabolic disorders, as well as prevent ageing. Nevertheless, the creation of Wnt-based therapies has been hampered by challenges in developing potent and selective Wnt activators without off-target effects, such as oncogenesis. On the other hand, to avoid these risks, their use to promote ex vivo expansion during tissue engineering is a promising application.

Phytochemistry and Pharmacological Activity of Plants of Genus Curculigo: An Updated Review Since 2013

The genus Curculigo, as a folk herbal medicine, has been used for many years in China, treating impotence, limb limpness, and arthritis of the lumbar and knee joints. The last systematic review of the genus Curculigo was written in 2013, scientifically categorizing the phytochemistry and biological activities. Hitherto, the original compounds and their pharmacological activities were presented as the development of this genus, but there is not an updated review. To conclude the progression of the genus Curculigo, we collected the new literature published from 2013 to 2021 in PubMed, Web of Science, Google Scholar databases, and the Chinese National Knowledge Infrastructure. The novel chlorophenolic glucosides, curculigine, phenolic glycosides, orcinosides and polysaccharides were isolated from Curculigo. The new analyzing methods were established to control the quality of Curculigo as a herbal medicine. In addition, the pharmacological effects of Curculigo focused on anti-diabetes, antibacterial, anti-inflammatory, osteoporosis, antioxidation, etc. The antitumor and neuroprotective activities were newly explored in recent years. The application of herbal medicine was gradually developed in scientific methods. The medicinal value of the genus Curculigo needs to further investigate its pharmacological mechanisms. This new review offers more insights into the exploitation of the pharmacological value of the genus Curculigo.

Small Molecule Wnt Pathway Modulators from Natural Sources: History, State of the Art and Perspectives

The Wnt signaling is one of the major pathways known to regulate embryonic development, tissue renewal and regeneration in multicellular organisms. Dysregulations of the pathway are a common cause of several types of cancer and other diseases, such as osteoporosis and rheumatoid arthritis. This makes Wnt signaling an important therapeutic target. Small molecule activators and inhibitors of signaling pathways are important biomedical tools which allow one to harness signaling processes in the organism for therapeutic purposes in affordable and specific ways. Natural products are a well known source of biologically active small molecules with therapeutic potential. In this article, we provide an up-to-date overview of existing small molecule modulators of the Wnt pathway derived from natural products. In the first part of the review, we focus on Wnt pathway activators, which can be used for regenerative therapy in various tissues such as skin, bone, cartilage and the nervous system. The second part describes inhibitors of the pathway, which are desired agents for targeted therapies against different cancers. In each part, we pay specific attention to the mechanisms of action of the natural products, to the models on which they were investigated, and to the potential of different taxa to yield bioactive molecules capable of regulating the Wnt signaling.

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.

Osteoblastic differentiation potential of human amniotic fluid-derived mesenchymal stem cells in different culture conditions

Osteoporosis is a bone degenerative disease characterized by a decrease in bone strength and an alteration in the osseous micro-architecture causing an increase in the risk of fractures. These diseases usually happen in post-menopausal women and elderly men. The most common treatment involves anti-resorptive agent drugs. However, the inhibition of bone resorption alone is not adequate for recovery in patients at the severe stage of osteoporosis who already have a fracture. Therefore, the combination of utilizing osteoblast micro mimetic scaffold in cultivation with the stimulation of osteoblastic differentiations to regain bone formation is a treatment strategy of considerable interest. The aims of this current study are to investigate the osteoblastic differentiation potential of mesenchymal stem cells derived from human amniotic fluid and to compare the monolayer culture and scaffold culture conditions. The results showed the morphology of cells in human amniotic fluid as f-type, which is a typical cell shape of mesenchymal stem cells. In addition, the proliferation rate of cells in human amniotic fluid reached the highest peak after 14 days of culturing. After which time, the growth rate slowly decreased. Moreover, the positive expression of specific mesenchymal cell surface markers including CD44, CD73, CD90, and also HLA-ABC (MHC class I) were recorded. On the other hand, the negative expressions of the endothelial stem cells markers (CD31), the hematopoietic stem cells markers (CD34, 45), the amniotic stem cells markers (CD117), and also the HLA-DR (MHC class II) were also recorded. The expressions of osteoblastogenic related genes including OCN, COL1A1, and ALP were higher in the osteogenic-induced group when compared to the control group. Interestingly, the osteoblastogenic related gene expressions that occurred under scaffold culture conditions were superior to the monolayer culture conditions. Additionally, higher ALP activity and greater calcium deposition were recorded in the extracellular matrix in the osteogenic-induced group than in the culture in the scaffold group. In summary, the mesenchymal stem cells derived from human amniotic fluid can be induced to be differentiated into osteoblastic-like cells and can promote osteoblastic differentiation using the applied scaffold.

The effects of verapamil on the pharmacokinetics of curculigoside in rats

CONTEXT

Clarifying the potential mechanism of the poor oral bioavailability of curculigoside would be helpful for for investigating pharmacological effects and clinical applications.

OBJECTIVE

To clarify the main mechanism for poor oral bioavailability.

MATERIALS AND METHODS

First, the pharmacokinetics of curculigoside (20 mg/kg) in rats with and without pretreatment with verapamil (10 mg/kg) was determined using a sensitive and reliable LC-MS method. Then the effects of verapamil on the transport and metabolic stability of curculigoside were investigated using Caco-2 cell transwell model and rat liver microsome incubation systems.

RESULTS

The results showed that verapamil could significantly increase the peak plasma concentration (from 60.17 ng/mL to 93.66 ng/mL) and AUC_0-t (from 289.57 to 764.02 ng·h/mL) of curculigoside. The Caco-2 cell experiments indicated that the efflux ratio of curculigoside was 3.92 (P_appAB 6.43 ± 0.57 × 10 ^-7cm/s; P_appBA 2.52 ± 0.37 × 10 ^-36cm/s), P-gp might be involved in the transport of curculigoside, and verapamil could inhibit the efflux of curculigoside and increase the absorption of curculigoside significantly in the Caco-2 cell monolayer. Additionally, the rat liver microsome incubation experiments indicated that verapamil could significantly decrease the intrinsic clearance rate of curculigoside (from 38.8 to 23.6 μL/min/mg protein).

DISCUSSION AND CONCLUSION

These results indicated that verapamil could significantly change the pharmacokinetic profiles of curculigoside in rats, the poor absorption due to P-gp mediated efflux in intestine and high intrinsic clearance rate in rat liver may be the main reason for the poor oral absolute bioavailability of curculigoside.

Osteogenic Differentiation of Human Amniotic Fluid Mesenchymal Stem Cells Is Determined by Epigenetic Changes

Osteogenic differentiation of human amniotic fluid derived mesenchymal stem cells (AF-MSCs) has been widely studied in vitro and in vivo as a potential tool for regenerative medicine and tissue engineering. While most of the studies analyze changes in transcriptional profile during differentiation to date there is not much information regarding epigenetic changes in AF-MSCs during differentiation. The aim of our study was to evaluate epigenetic changes during osteogenic differentiation of AF-MS cells. Isolated AF-MSCs were characterized morphologically and osteogenic differentiation was confirmed by cell staining and determining expression of alkaline phosphatase and osteopontin by RT-qPCR. Variation in gene expression levels of pluripotency markers and specific microRNAs were also evaluated. Analysis of epigenetic changes revealed that levels of chromatin modifying enzymes such as Polycomb repressive complex 2 (PRC2) proteins (EZH2 and SUZ12), DNMT1, HDAC1, and HDAC2 were reduced after osteogenic differentiation of AF-MSCs. We demonstrated that the level of specific histone markers keeping active state of chromatin (H3K4me3, H3K9Ac, and others) increased and markers of repressed state of chromatin (H3K27me3) decreased. Our results show that osteogenic differentiation of AF-MSCs is conducted by various epigenetic alterations resulting in global chromatin remodeling and provide insights for further epigenetic investigations in human AF-MSCs.

Effects of Curculigoside on Memory Impairment and Bone Loss via Anti-Oxidative Character in APP/PS1 Mutated Transgenic Mice

Alzheimer's disease (AD) and osteoporosis are two closely related multifactorial progressively degenerative diseases that predominantly affect aged people. These two diseases share many common risk factors, including old age, being female, smoking, excessive drinking, low estrogen, and vitamin D3 levels. Additionally, oxidative damage and the dysfunction of the antioxidant system play important roles in the pathogenesis of osteoporosis and AD. Aβ not only leads to impaired memory but also plays a crucial role in the demineralization process of bone tissues of older people and women with menopause. Curculigoside can promote calcium deposition and increase the levels of ALP and Runx2 in osteoblasts under oxidative stress via anti-oxidative character. Therefore, we investigated the effects of CUR on the spatial learning and memory by the Morris water maze and brain immunohistochemistry, and bone microstructure and material properties of femurs by micro-computed tomography and mechanical testing in APP/PS1 mutated transgenic mice. Oral administration of CUR can significantly enhance learning performance and ameliorate bone loss in APP/PS1 mutated transgenic mice, and the mechanism may be related to its antioxidant effect. Based on these results, CUR has real potential as a new natural resource for developing medicines or dietary supplements for the prevention and treatment of the two closely linked multifactorial progressive degenerative disorders, AD and osteoporosis.

Stem cell regenerative therapy in alveolar cleft reconstruction

Achieving a successful and well-functioning reconstruction of craniofacial deformities still remains a challenge. As for now, autologous bone grafting remains the gold standard for alveolar cleft reconstruction. However, its aesthetic and functional results often remain unsatisfactory, which carries a long-term psychosocial and medical sequelae. Therefore, searching for novel therapeutic approaches is strongly indicated. With the recent advances in stem cell research, cell-based tissue engineering strategies move from the bench to the patients' bedside. Successful stem cell engineering employs a carefully selected stem cell source, a biodegradable scaffold with osteoconductive and osteoinductive properties, as well as an addition of growth factors or cytokines to enhance osteogenesis. This review highlights recent advances in mesenchymal stem cell tissue engineering, discusses animal models and case reports of stem cell enhanced bone regeneration, as well as ongoing clinical trials.

Osteogenic differentiation of amniotic fluid mesenchymal stromal cells and their bone regeneration potential

In orthopedics, tissue engineering approach using stem cells is a valid line of treatment for patients with bone defects. In this context, mesenchymal stromal cells of various origins have been extensively studied and continue to be a matter of debate. Although mesenchymal stromal cells from bone marrow are already clinically applied, recent evidence suggests that one may use mesenchymal stromal cells from extra-embryonic tissues, such as amniotic fluid, as an innovative and advantageous resource for bone regeneration. The use of cells from amniotic fluid does not raise ethical problems and provides a sufficient number of cells without invasive procedures. Furthermore, they do not develop into teratomas when transplanted, a consequence observed with pluripotent stem cells. In addition, their multipotent differentiation ability, low immunogenicity, and anti-inflammatory properties make them ideal candidates for bone regenerative medicine. We here present an overview of the features of amniotic fluid mesenchymal stromal cells and their potential in the osteogenic differentiation process. We have examined the papers actually available on this regard, with particular interest in the strategies applied to improve in vitro osteogenesis. Importantly, a detailed understanding of the behavior of amniotic fluid mesenchymal stromal cells and their osteogenic ability is desirable considering a feasible application in bone regenerative medicine.

Effects of naringin on the proliferation and osteogenic differentiation of human amniotic fluid-derived stem cells

Human amniotic fluid-derived stem cells (hAFSCs) are a novel cell source for generating osteogenic cells to treat bone diseases. Effective induction of osteogenic differentiation from hAFSCs is critical to fulfil their therapeutic potential. In this study, naringin, the main active compound of Rhizoma drynariae (a Chinese herbal medicine), was used to stimulate the proliferation and osteogenic differentiation of hAFSCs. The results showed that naringin enhanced the proliferation and alkaline phosphatase activity (ALP) of hAFSCs in a dose-dependent manner in the range 1-100 µg/ml, while an inhibition effect was observed at 200 µg/ml. Consistently, the calcium content also increased with naringin concentration up to 100 µg/ml. The enhanced osteogenic differentiation of hAFSCs by naringin was further confirmed by the dose-dependent upregulation of marker genes, including osteopontin (OPN) and Collagen I from RT-PCR analysis. The increased osteoprotegerin (OPG) expression and minimal expression of receptor activator of nuclear factor-κB ligand (RANKL) suggested that naringin also inhibited osteoclastogenesis of hAFSCs. In addition, the gene expressions of bone morphogenetic protein 4 (BMP4), runt-related transcription factor 2 (RUNX2), β-catenin and Cyclin D1 also increased significantly, indicating that naringin promotes the osteogenesis of hAFSCs via the BMP and Wnt-β-catenin signalling pathways. These results suggested that naringin can be used to upregulate the osteogenic differentiation of hAFSCs, which could provide an attractive and promising treatment for bone disorders. Copyright © 2014 John Wiley & Sons, Ltd.