Curcumin (diferuloylmethane) inhibits receptor activator of NF-kappa B ligand-induced NF-kappa B activation in osteoclast precursors and suppresses osteoclastogenesis

Curcumin Inhibits Lipopolysaccharide-Induced Inflammation Through the HMGB1/NF-κB Signaling Pathway to Promote the Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells

Curcumin has strong anti-inflammatory properties and promotes the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). The aim of this study was to explore the role and potential molecular mechanism of curcumin in ameliorating osteogenic differentiation disorders caused by inflammation. We used LPS to induce an inflammatory response in hBMSCs. The expression of related mRNAs and proteins was detected by RT‒qPCR, Western blotting, immunofluorescence, and ELISA. The osteogenic differentiation of hBMSCs was detected by alkaline phosphatase (ALP) staining and alizarin red S (ARS) staining. The results showed that after LPS treatment, the levels of the inflammatory cytokines TNF-α, IL-6 and IL-1β in hBMSCs increased, and the activity of ALP, the level of calcium salt deposition and the expression levels of the osteogenic proteins Runx2, COL1, OCN and OPN significantly decreased. The curcumin treatment alleviated this effect. These results indicated that curcumin improved the LPS-induced inflammation and osteogenic differentiation disorder in hBMSCs. Further studies revealed that the therapeutic effect of curcumin was caused by the inhibition of HMGB1 expression. From a mechanistic perspective, curcumin inhibits LPS-induced inflammation by inhibiting the expression of HMGB1, thereby inhibiting the NF-κB pathway and activating the NRF2 pathway, thereby improving the disordered osteogenic differentiation of hBMSCs. In conclusion, curcumin can reduce the LPS-induced inflammation of hBMSCs and ameliorate their osteogenic differentiation disorders.

Bovine collagen peptides and peptide-calcium complexes inhibit RANKL-induced osteoclast differentiation in RAW 264.7 macrophages

BACKGROUND

This study aims to prepare collagen peptides from bovine bone meal using a combination of heat pretreatment and enzymatic digestion, and to chelate them with calcium chloride to form peptide-calcium chelates. The effects of both on the proliferation and differentiation of osteoclasts were investigated using cellular experiments (RAW 264.7 cells).

RESULTS

Both bovine collagen peptides and their calcium chelates (BPs, HBPs, BPs-Ca, and HBPs-Ca) can significantly inhibit the RANKL-induced differentiation of RAW 264.7 cells into osteoclasts. The preheating treatment before enzymatic hydrolysis of bone materials has an improving effect on the inhibition of RAW 264.7 differentiation into osteoblasts by collagen peptides and their peptide calcium chelates. HBP and HBPs-Ca could significantly activate the NF-κB signaling pathway, among which HBPs-Ca was the most effective, which could significantly downregulate the mRNA expression of genes related to osteoclast differentiation, such as AP-1, c-Fos, TRAP, and NFATc1. Additionally, the expression of NF-κB p65, c-Fos, IKK and IκBα were also significantly inhibited after treatment with HBPs-Ca, with IKK being the most significantly downregulated, with an 8.2-fold reduction compared to the control group.

CONCLUSION

HBPs and HBPs-Ca demonstrated stronger activity in inhibiting osteoclast formation compared to BPs and BPs-Ca. This enhanced activity is likely due to structural changes in the peptides caused by heat treatment, which increase their antioxidant properties and antagonistic effects on RANKL. These findings indicate that bovine collagen peptides and their calcium chelates can inhibit the formation of osteoclasts by activating the NF-κB pathway, thereby influencing bone metabolism and providing a theoretical basis for the treatment of osteoporosis. © 2025 Society of Chemical Industry.

Biomaterial Cues for Regulation of Osteoclast Differentiation and Function in Bone Regeneration

Tissue regeneration involves dynamic dialogue between and among different cells and their surrounding matrices. Bone regeneration is specifically governed by reciprocity between osteoblasts and osteoclasts within the bone microenvironment. Osteoclast-directed resorption and osteoblast-directed formation of bone are essential to bone remodeling, and the crosstalk between these cells is vital to curating a sequence of events that culminate in the creation of bone tissue. Among bone biomaterial strategies, many have investigated the use of different material cues to direct the development and activity of osteoblasts. However, less attention has been given to exploring features that similarly target osteoclast formation and activity, with even fewer strategies demonstrating or integrating biomaterial-directed modulation of osteoblast-osteoclast coupling. This review aims to describe various biomaterial cues demonstrated to influence osteoclastogenesis and osteoclast function, emphasizing those that enhance a material construct's ability to achieve bone healing and regeneration. Additionally discussed are approaches that influence the communication between osteoclasts and osteoblasts, particularly in a manner that takes advantage of their coupling. Deepening our understanding of how biomaterial cues may dictate osteoclast differentiation, function, and influence on the microenvironment may enable the realization of bone-replacement interventions with enhanced integrative and regenerative capacities.

Curcumin administration mitigates periodontitis-induced tissue damage in hypercholesterolemic rats: a natural preventive approach

This study investigated the preventive effect of curcumin (CUR) on tooth-supporting structures in hypercholesterolemic (HC) rats with periodontitis (P). Wistar rats (8 weeks old) (n = 30) were assigned to six groups based on dietary intake, CUR-piperine combination treatment and P induction. P was induced in four groups using a ligature model. Serum lipid profiles, oxidative stress parameters, radiographic, histological and histomorphometric analyses were performed. HC rats showed elevated serum cholesterol levels (p < 0.001). Moreover, topical administration of CUR did not regulate hypercholesterolemia in this model. The HC diet increased oxidative stress in gingival tissue, exacerbated by P, whereas CUR attenuated reactive species generation (p < 0.001) and reduced catalase (CAT) activity, possibly due to its antioxidant properties. Histological analysis revealed extensive erosive surfaces and osteoclast presence in the P groups, with the HC + P group showing the highest rate of bone resorption. The CUR-treated groups showed less bone resorption and more bone formation, indicating a protective effect. Histomorphometric studies showed a significant increase in bone volume in the CUR groups compared to the P groups (p < 0.001). CUR prevented bone resorption induced by P and HC diet, with larger osteoblastic surfaces and fewer osteoclasts, suggesting inhibition of bone resorption. CUR also prevented collagen fiber destruction caused by the HC diet. Overall, the study suggests a potential therapeutic role for CUR in mitigating periodontal tissue damage associated with hypercholesterolemia and P, due to its antioxidant and anti-inflammatory properties. Further research would be needed to validate its clinical efficacy as an adjunctive treatment for P.

Nutraceuticals in osteoporosis prevention

Nutraceuticals are gaining popularity as they can contribute to bone health by delaying the onset or slowing down the progression of pathological bone loss. Osteoporosis's bone loss is a concern for older adults and a crucial aspect of aging. Maintaining healthy bones is the key to living a full and active life. Our review explores the current knowledge on the role of nutraceuticals in preventing osteoporosis by focusing on three main aspects. First, we provide an overview of osteoporosis. Second, we discuss the latest findings on natural nutraceuticals and their efficacy in reducing bone loss, emphasizing clinical trials. Third, we conduct a structured analysis to evaluate nutraceuticals' pros and cons and identify translational gaps. In conclusion, we must address several challenges to consolidate our knowledge, better support clinicians in their prescriptions, and provide people with more reliable nutritional recommendations to help them lead healthier lives.

Ginseng (Panax ginseng) leaf extract modulates the expression of heme oxygenase-1 to attenuate osteoclast differentiation

Osteoporosis is an aging disease characterized by an imbalance between bone formation and resorption. However, drugs that inhibit bone resorption have various adverse effects. Ginseng (Panax ginseng), a prominent herbal medicine in East Asia for >2000 years, is renowned for its manifold beneficial properties, including antioxidant, anti-cancer, anti-diabetic, and anti-adipogenic activities. Despite its long history of use, the pharmacological functions of ginseng leaves are not yet fully comprehended. In this study, we evaluated the potential effects of ginseng leaf extract (GLE) on receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast differentiation in RAW264.7 macrophage cells. Tartrate-resistant acid phosphatase (TRAP) staining revealed that GLE had significant anti-osteoclastogenic activity. GLE significantly reduced mRNA levels of osteoclast differentiation markers including TRAP, nuclear factor of activated T cell cytoplasmic 1, and cathepsin K. It also suppressed the production of reactive oxygen species (ROS) and secretion of high mobility group box-1 (HMGB1) in RANKL-treated RAW264.7 cells. In addition, GLE upregulated dose- and time-dependently the expression of heme oxygenase-1 (HO-1), eventually suppressing ROS production and HMGB1 secretion. This effects of GLE were significantly reversed by Tin Protoporphyrin IX dichloride, an inhibitor of HO-1, and HO-1 shRNA, indicating that HO-1 potently inhibits RANKL-induced osteoclast differentiation by inhibiting ROS production and HMGB1 secretion. Taken together, these observations suggest that GLE could have therapeutic potential as a natural product-derived medicine for the treatment of bone disorders.

Curcumin suppresses RANKL-induced osteoclast precursor autophagy in osteoclastogenesis by inhibiting RANK signaling and downstream JNK-BCL2-Beclin1 pathway

BACKGROUND

Curcumin ameliorates bone loss by inhibiting osteoclastogenesis. Curcumin inhibits RANKL-promoted autophagy in osteoclast precursors (OCPs), which mediates its anti-osteoclastogenic effect. But the role of RANKL signaling in curcumin-regulated OCP autophagy is unknown. This study aimed to explore the relationship between curcumin, RANKL signaling, and OCP autophagy during osteoclastogenesis.

METHODS

We investigated the role of curcumin in RANKL-related molecular signaling in OCPs, and identified the significance of RANK-TRAF6 signaling in curcumin-treated osteoclastogenesis and OCP autophagy using flow sorting and lentiviral transduction. Tg-hRANKL mice were used to observe the in vivo effects of curcumin on RANKL-regulated bone loss, osteoclastogenesis, and OCP autophagy. The significance of JNK-BCL2-Beclin1 pathway in curcumin-regulated OCP autophagy with RANKL was explored via rescue assays and BCL2 phosphorylation detection.

RESULTS

Curcumin inhibited RANKL-related molecular signaling in OCPs, and repressed osteoclast differentiation and autophagy in sorted RANK+ OCPs but did not affect those of RANK- OCPs. Curcumin-inhibited osteoclast differentiation and OCP autophagy were recovered by TRAF6 overexpression. But curcumin lost these effects under TRAF6 knockdown. Furthermore, curcumin prevented the decrease in bone mass and the increase in trabecular osteoclast formation and autophagy in RANK+ OCPs in Tg-hRANKL mice. Additionally, curcumin-inhibited OCP autophagy with RANKL was reversed by JNK activator anisomycin and TAT-Beclin1 overexpressing Beclin1. Curcumin inhibited BCL2 phosphorylation at Ser70 and enhanced protein interaction between BCL2 and Beclin1 in OCPs.

CONCLUSIONS

Curcumin suppresses RANKL-promoted OCP autophagy by inhibiting signaling pathway downstream of RANKL, contributing to its anti-osteoclastogenic effect. Moreover, JNK-BCL2-Beclin1 pathway plays an important role in curcumin-regulated OCP autophagy.

The entrancing role of dietary polyphenols against the most frequent aging-associated diseases

Aging, a fundamental physiological process influenced by innumerable biological and genetic pathways, is an important driving factor for several aging-associated disorders like diabetes mellitus, osteoporosis, cancer, and neurodegenerative diseases including Alzheimer's and Parkinson's diseases. In the modern era, the several mechanisms associated with aging have been deeply studied. Treatment and therapeutics for age-related diseases have also made considerable advances; however, for the effective and long-lasting treatment, nutritional therapy particularly including dietary polyphenols from the natural origin are endorsed. These dietary polyphenols (e.g., apigenin, baicalin, curcumin, epigallocatechin gallate, kaempferol, quercetin, resveratrol, and theaflavin), and many other phytochemicals target certain molecular, genetic mechanisms. The most common pathways of age-associated diseases are mitogen-activated protein kinase, reactive oxygen species production, nuclear factor kappa light chain enhancer of activated B cells signaling pathways, metal chelation, c-Jun N-terminal kinase, and inflammation. Polyphenols slow down the course of aging and help in combatting age-linked disorders. This exemplified in the form of clinical trials on specific dietary polyphenols in various aging-associated diseases. With this context in mind, this review reveals the new insights to slow down the aging process, and consequently reduce some classic diseases associated with age such as aforementioned, and targeting age-associated diseases by the activities of dietary polyphenols of natural origin.

Regression of Intermediate-High Risk Monoclonal Gammopathy of Undetermined Significance (MGUS) With Long-term Use of Curcumin: A Case Report

Patients with intermediate-high risk MGUS are not offered therapeutic options to date and standard of care remains observation with re-evaluations of the patient every 3 to 6 months. Given the persistent risk of progression as well as potential complications experienced by some, and anxiety experienced by most patients, early intervention with non-toxic curcumin, aimed at potentially slowing down or stopping disease progression might be therapeutic. We present here an intermediate-high risk MGUS patient who has been taking curcumin for 16 years and has shown a decrease in disease markers and an increase in uninvolved immunoglobulins, adding to the body of evidence of benefit of curcumin to MGUS patients.

Functional Ingredients Associated with the Prevention and Suppression of Locomotive Syndrome: A Review

In 2007, the Japanese Orthopaedic Association proposed the concept of locomotive syndrome, a comprehensive description of conditions involving the functional decline of the locomotor system. Locomotive syndrome includes bone-related diseases such as osteoporosis, joint cartilage and disc-related diseases such as osteoarthritis and lumbar spondylosis, and sarcopenia and locomotive syndrome-related diseases. If left untreated, these diseases are likely to reduce mobility, necessitating nursing care. To prevent the progression of locomotive syndrome, a daily exercise routine and well-balanced diet are important, in addition to recognizing one's own decline in mobility. Therefore, research on the effectiveness of functional ingredients in the prevention and suppression of locomotive syndrome progression is ongoing. In this review, we summarize the latest reports on the effectiveness of five functional ingredients, namely, epigallocatechin gallate, resveratrol, curcumin, ellagic acid, and carnosic acid, in the treatment of osteoarthritis, osteoporosis, and rheumatoid arthritis, which are considered representative diseases of the locomotive syndrome.

Modified Curcuminoid-Rich Extract Liposomal CRE-SDInhibits Osteoclastogenesis via the Canonical NF-κB Signaling Pathway

Curcuminoids, namely curcumin, demethoxycurcumin, and bisdemethoxycurcumin, are the major active compounds found in Curcuma longa L. (turmeric). Although their suppressive effects on bone resorption have been demonstrated, their pharmacokinetic disadvantages remain a concern. Herein, we utilized solid dispersion of a curcuminoid-rich extract (CRE), comprising such curcuminoids, to prepare CRE-SD; subsequently, we performed liposome encapsulation of the CRE-SD to yield liposomal CRE-SD. In vitro release assessment revealed that a lower cumulative mass percentage of CRE-SD was released from liposomal CRE-SD than from CRE-SD samples. After culture of murine RANKL-stimulated RAW 264.7 macrophages, our in vitro examinations confirmed that liposomal CRE-SD may impede osteoclastogenesis by suppressing p65 and IκBα phosphorylation, together with nuclear translocation and transcriptional activity of phosphorylated p65. Blind docking simulations showed the high binding affinity between curcuminoids and the IκBα/p50/p65 protein complex, along with many intermolecular interactions, which corroborated our in vitro findings. Therefore, liposomal CRE-SD can inhibit osteoclastogenesis via the canonical NF-κB signaling pathway, suggesting its pharmacological potential for treating bone diseases with excessive osteoclastogenesis.

From Cells to Environment: Exploring the Interplay between Factors Shaping Bone Health and Disease

The skeletal system is an extraordinary structure that serves multiple purposes within the body, including providing support, facilitating movement, and safeguarding vital organs. Moreover, it acts as a reservoir for essential minerals crucial for overall bodily function. The intricate interplay of bone cells plays a critical role in maintaining bone homeostasis, ensuring a delicate balance. However, various factors, both intrinsic and extrinsic, can disrupt this vital physiological process. These factors encompass genetics, aging, dietary and lifestyle choices, the gut microbiome, environmental toxins, and more. They can interfere with bone health through several mechanisms, such as hormonal imbalances, disruptions in bone turnover, direct toxicity to osteoblasts, increased osteoclast activity, immune system aging, impaired inflammatory responses, and disturbances in the gut-bone axis. As a consequence, these disturbances can give rise to a range of bone disorders. The regulation of bone's physiological functions involves an intricate network of continuous processes known as bone remodeling, which is influenced by various intrinsic and extrinsic factors within the organism. However, our understanding of the precise cellular and molecular mechanisms governing the complex interactions between environmental factors and the host elements that affect bone health is still in its nascent stages. In light of this, this comprehensive review aims to explore emerging evidence surrounding bone homeostasis, potential risk factors influencing it, and prospective therapeutic interventions for future management of bone-related disorders.

Pro-Osteogenic and Anti-Inflammatory Synergistic Effect of Orthosilicic Acid, Vitamin K2, Curcumin, Polydatin and Quercetin Combination in Young and Senescent Bone Marrow-Derived Mesenchymal Stromal Cells

During aging, bone marrow mesenchymal stromal cells (MSCs)-the precursors of osteoblasts-undergo cellular senescence, losing their osteogenic potential and acquiring a pro-inflammatory secretory phenotype. These dysfunctions cause bone loss and lead to osteoporosis. Prevention and intervention at an early stage of bone loss are important, and naturally active compounds could represent a valid help in addition to diet. Here, we tested the hypothesis that the combination of two pro-osteogenic factors, namely orthosilicic acid (OA) and vitamin K2 (VK2), and three other anti-inflammatory compounds, namely curcumin (CUR), polydatin (PD) and quercetin (QCT)-that mirror the nutraceutical BlastiMin Complex^® (Mivell, Italy)-would be effective in promoting MSC osteogenesis, even of replicative senescent cells (sMSCs), and inhibiting their pro-inflammatory phenotype in vitro. Results showed that when used at non-cytotoxic doses, (i) the association of OA and VK2 promoted MSC differentiation into osteoblasts, even when cultured without other pro-differentiating factors; and (ii) CUR, PD and QCT exerted an anti-inflammatory effect on sMSCs, and also synergized with OA and VK2 in promoting the expression of the pivotal osteogenic marker ALP in these cells. Overall, these data suggest a potential role of using a combination of all of these natural compounds as a supplement to prevent or control the progression of age-related osteoporosis.

Anti-Oxidant Multi-Functionalized Materials: Strontium-Substituted Monetite and Brushite as Delivery Systems for Curcumin

Curcumin has numerous biological activities and pharmaceutical applications related to its ability to inhibit reactive oxygen species. Herein, strontium-substituted monetite (SrDCPA) and strontium-substituted brushite (SrDCPD) were synthesized and further functionalized with curcumin with the aim to develop materials that combine the anti-oxidant properties of the polyphenol, the beneficial role of strontium toward bone tissue, and the bioactivity of calcium phosphates. Adsorption from hydroalcoholic solution increases with time and curcumin concentration, up to about 5-6 wt%, without affecting the crystal structure, morphology, and mechanical response of the substrates. The multi-functionalized substrates exhibit a relevant radical scavenging activity and a sustained release in phosphate buffer. Cell viability, morphology, and expression of the most representative genes were tested for osteoclast seeded in direct contact with the materials and for osteoblast/osteoclast co-cultures. The materials at relatively low curcumin content (2-3 wt%) maintain inhibitory effects on osteoclasts and support the colonization and viability of osteoblasts. The expressions of Alkaline Phosphatase (ALPL), collagen type I alpha 1 chain (COL1A1), and osteocalcin (BGLAP) suggest that curcumin reduces the osteoblast differentiation state but yields encouraging osteoprotegerin/receptor activator for the NFkB factor ligand (OPG/RANKL) ratio.

Therapeutic Effects of Curcumin Liposomes and Nanocrystals on Inflammatory Osteolysis: In Vitro and In Vivo Comparative Study

Curcumin could inhibit periprosthetic osteolysis induced by wear debris and adherent endotoxin, which commonly cause prosthesis loosening and negatively influence the long-term survival of joint arthroplasty. However, its limited water solubility and poor stability pose challenges for its further clinical application. To address these issues, we developed curcumin liposomes for intraarticular injection, as liposomes possess good lubricant capacity and pharmacological synergy with curcumin. Additionally, a nanocrystal dosage form was prepared to enable comparison with the liposomes based on their ability to disperse curcumin effectively. A microfluidic method was used for its controllability, repeatability, and scalability. The Box-Behnken Design was employed to screen the formulations and flow parameters, while computational fluid dynamics was used to simulate the mixing process and predict the formation of liposomes. The optimized curcumin liposomes (Cur-LPs) had a size of 132.9nm and an encapsulation efficiency of 97.1%, whereas the curcumin nanocrystals (Cur-NCs) had a size of 172.3nm. Both Cur-LPs and Cur-NCs inhibited LPS-induced pro-inflammatory polarization of macrophages and reduced the expression and secretion of inflammatory factors. The mouse air pouch model further demonstrated that both dosage forms attenuated inflammatory cell infiltration and inflammatory fibrosis in subcutaneous tissues. Interestingly, the anti-inflammatory effect of Cur-LPs was more potent than that of Cur-NCs, both in vitro and in vivo, although the cellular uptake of Cur-NCs was quicker. In conclusion, the results demonstrate that Cur-LPs have great potential for the clinical treatment of inflammatory osteolysis and that the therapeutic effect is closely related to the liposomal dosage form.

NF-κB Decoy ODN-Loaded Poly(Lactic-co-glycolic Acid) Nanospheres Inhibit Alveolar Ridge Resorption

Residual ridge resorption combined with dimensional loss resulting from tooth extraction has a prolonged correlation with early excessive inflammation. Nuclear factor-kappa B (NF-κB) decoy oligodeoxynucleotides (ODNs) are double-stranded DNA sequences capable of downregulating the expression of downstream genes of the NF-κB pathway, which is recognized for regulating prototypical proinflammatory signals, physiological bone metabolism, pathologic bone destruction, and bone regeneration. The aim of this study was to investigate the therapeutic effect of NF-κB decoy ODNs on the extraction sockets of Wistar/ST rats when delivered by poly(lactic-co-glycolic acid) (PLGA) nanospheres. Microcomputed tomography and trabecular bone analysis following treatment with NF-κB decoy ODN-loaded PLGA nanospheres (PLGA-NfDs) demonstrated inhibition of vertical alveolar bone loss with increased bone volume, smoother trabecular bone surface, thicker trabecular bone, larger trabecular number and separation, and fewer bone porosities. Histomorphometric and reverse transcription-quantitative polymerase chain reaction analysis revealed reduced tartrate-resistant acid phosphatase-expressing osteoclasts, interleukin-1β, tumor necrosis factor-α, receptor activator of NF-κB ligand, turnover rate, and increased transforming growth factor-β1 immunopositive reactions and relative gene expression. These data demonstrate that local NF-κB decoy ODN transfection via PLGA-NfD can be used to effectively suppress inflammation in a tooth-extraction socket during the healing process, with the potential to accelerate new bone formation.

Monoclonal Gammopathies and the Bone Marrow Microenvironment: From Bench to Bedside and Then Back Again

Multiple myeloma (MM) is an incurable hematologic malignancy characterized by a multistep evolutionary pathway, with an initial phase called monoclonal gammopathy of undetermined significance (MGUS), potentially evolving into the symptomatic disease, often preceded by an intermediate phase called "smoldering" MM (sMM). From a biological point of view, genomic alterations (translocations/deletions/mutations) are already present at the MGUS phase, thus rendering their role in disease evolution questionable. On the other hand, we currently know that changes in the bone marrow microenvironment (TME) could play a key role in MM evolution through a progressive shift towards a pro-inflammatory and immunosuppressive shape, which may drive cancer progression as well as clonal plasma cells migration, proliferation, survival, and drug resistance. Along this line, the major advancement in MM patients' survival has been achieved by the introduction of microenvironment-oriented drugs (including immunomodulatory drugs and monoclonal antibodies). In this review, we summarized the role of the different components of the TME in MM evolution from MGUS as well as potential novel therapeutic targets/opportunities.

Drug-Loaded and Anisotropic Wood-Derived Hydrogel Periosteum with Super Antibacterial, Anti-Inflammatory, and Osteogenic Activities

Current artificial periostea mainly focus on osteogenic activity but overlook structural and mechanical anisotropy, as well as the importance of antibacterial and anti-inflammatory properties. Here, inspired by the anisotropic structure of wood, the delignified wood (named white wood, WW) with a porous and highly oriented cellulose fiber skeleton was obtained, which was further filled with polyvinyl alcohol (PVA) hydrogel loaded with curcumin (Cur) and phytic acid (PA). The prepared wood-derived hydrogel composite membranes can not only exhibit an obvious anisotropic structure and good mechanical properties but also sustainably release loaded drugs to obtain long-term biological activities. Creatively, PA can effectively improve the bioavailability of Cur; more importantly, Cur and PA play an obvious synergistic effect in antibacterial, anti-inflammatory, and osteogenic activities. Compared with the wood-derived hydrogel composite membranes without drug loading, as well as loaded with Cur or PA only, these loaded with Cur and PA are significantly more conducive to inhibiting the growth of bacteria and inflammatory response and facilitating the adhesion, proliferation, and osteogenic differentiation of bone marrow mesenchymal stem cells. This kind of anisotropic wood-derived hydrogel composite membrane with fantastic antibacterial, anti-inflammatory, and osteogenic activities is expected to be ideal artificial periostea.

Graphene oxide reinforced SrHAP composite as a drug carrier in bone regeneration

Strontium substituted HAP (SrHAP), with a 10 mol% substitution, was mineralized on increasing weight percentages of graphene oxide (2, 4 and 6). The GS composites were comprehensively characterized for drug delivery in bone reconstruction. The formation of SrHAP was verified by XRD and FT-IR results. The apatite crystallization was influenced by graphene oxide content and strontium. The EDS results confirmed the presence of strontium and HR-SEM depicted rod shape apatite, of length between 58 and 135 nm, uniformly embedded on graphene oxide. The reinforcement of graphene oxide increased the surface area, porosity, microhardness (upto 0.59 GPa), protein adsorption (upto 18.16 μg/mg), water uptake and degradation properties. Also, the increase in graphene oxide fraction significantly enhanced the curcumin encapsulation efficiency (upto 80.16%) and the drug release was considerably retarded over SrHAP. The in vitro studies using human osteoblast-like MG-63 cells demonstrated that curcumin-loaded composite was biocompatible and promoted proliferation, differentiation and matrix mineralization. The results highlight the combinational therapy of osteogenic ion (strontium) and osteogenic drug (curcumin) as a promising platform in bone tissue engineering.

Effects of Resveratrol, Curcumin and Quercetin Supplementation on Bone Metabolism—A Systematic Review

Phenolic compounds are natural phytochemicals that have recently reported numerous health benefits. Resveratrol, curcumin, and quercetin have recently received the most attention among these molecules due to their documented antioxidant effects. The review aims to investigate the effects of these molecules on bone metabolism and their role in several diseases such as osteopenia and osteoporosis, bone tumours, and periodontitis. The PubMed/Medline, Web of Science, Google Scholar, Scopus, Cochrane Library, and Embase electronic databases were searched for papers in line with the study topic. According to an English language restriction, the screening period was from January 2012 to 3 July 2022, with the following Boolean keywords: (“resveratrol” AND “bone”); (“curcumin” AND “bone”); (“quercetin” AND “bone”). A total of 36 papers were identified as relevant to the purpose of our investigation. The studies reported the positive effects of the investigated phenolic compounds on bone metabolism and their potential application as adjuvant treatments for osteoporosis, bone tumours, and periodontitis. Furthermore, their use on the titanium surfaces of orthopaedic prostheses could represent a possible application to improve the osteogenic processes and osseointegration. According to the study findings, resveratrol, curcumin, and quercetin are reported to have a wide variety of beneficial effects as supplement therapies. The investigated phenolic compounds seem to positively mediate bone metabolism and osteoclast-related pathologies.

Vitamin D and curcumin-loaded PCL nanofibrous for engineering osteogenesis and immunomodulatory scaffold

The accelerating bone healing process is still a major challenge in clinical orthopedics, especially in critical-sized bone defects. Recently, Nanofiber membranes are showing increasing attention in the biomedical field due to their good biocompatibility, mechanical stability, and the ability to work as a drug carrier to achieve localized and sustained drug delivery. Herein, a multifunction nanofiber membrane loaded with vitamin D (Vit D) and curcumin (Cur) was successfully fabricated using electrospinning technology. In addition, we innovatively modified Vit D with PEG to improve the hydrophilicity of PCL nanofibers. The vitro results of CCK-8, alkaline phosphatase (ALP) and mineralization demonstrated that the PCL/Vit D-Cur membrane had great potential for enhancing the proliferation/differentiation of osteoblasts. Moreover, the synergistic effect of Vit D-Cur loaded PCL nanofiber membrane showed a superior ability to improve the anti-inflammatory activity through M2 polarization. Furthermore, in vivo results confirmed that the defect treated with PCL/Vit D-Cur nanofiber membrane was filled with the newly formed bone after 1 month. These results indicate that the Vit D/Cur loaded membrane can be applied for potential bone regeneration therapy.

Tripeptide IRW Protects MC3T3-E1 Cells against Ang II Stress in an AT2R Dependent Manner

Multiple strategies including the use of bioactive peptides and other nutraceuticals are being adopted to maintain bone health. This study provides an improved and deeper understanding of the pharmacological effects that a bioactive peptide IRW (Ile-Arg-Trp) extends on bone health. Our results showed that IRW treatment protects osteoblasts against Ang II induced decline in cell proliferation and restores protein levels of collagen type I alpha 2 chain (COL1A2) and alkaline phosphatase (ALP) levels in MC3T3-E1 cells (p < 0.05). Apart from augmentation of these mineralization factors, the angiotensin II (Ang II) induced apoptotic stress in osteoblasts was mitigated by IRW as well. At the molecular level, IRW abolished the cytochrome-c release via modulation of pro-and anti-apoptotic genes in MC3T3-E1 cells (p < 0.05). Interestingly, IRW also increased cellular levels of cytoprotective local RAAS factors such as MasR, Ang (1−7), ACE2, and AT2R, and lowered the levels of Ang II effector receptor (AT1R). Further, our results indicated a lower content of inflammation and osteoclastogenesis biomarkers such as cyclooxygenase 2 (COX2), nuclear factor kappa B (NF-κB), and receptor activator of nuclear factor kappa-B ligand (RANKL) following IRW treatment in MC3T3-E1 cells (p < 0.05). The use of an antagonist-guided cell study indicated that IRW contributed to the process of cytoprotection and proliferation of osteoblasts via Runt-related transcription factor 2 (RUNX2) in face of Ang II stress in an AT2R dependent manner. The key findings of our study showed that IRW could potentially have a therapeutic role in the treatment and/or prevention of bone disorders.

Biochemometry-Based Discovery of Phenylpropanoids from Azadirachta indica Fruits as Inhibitors of In Vitro Osteoclast Formation

(1) Background: Inhibition of osteoclast differentiation is the key approach in treating osteoporosis. However, using state-of-the-art treatments such as bisphosphonates and estrogen-based therapy is usually accompanied by many side effects. As opposed to this, the use of natural products as an osteoporotic remedy delivers promising outcomes with minimal side effects. (2) Methods: In the present study, we implemented a biochemometric workflow comprising (i) chemometric approaches using NMR and mass spectrometry and (ii) cell biological approaches using an osteoclast cytochemical marker (TRAP). The workflow serves as a screening tool to pursue potential in vitro osteoclast inhibitors. (3) Results: The workflow allowed for the selective isolation of two phenylpropanoids (coniferyl alcohol and sinapyl alcohol) from the fruits of neem tree (Azadirachta indica). These two isolated phenylpropanoids showed a very promising dose-dependent inhibition of osteoclast differentiation with negligible effects in terms of cell viability. (4) Conclusion: The presented workflow is an effective tool in the discovery of potential candidates for osteoclast inhibition from complex extracts. The used biochemometric approach saves time, effort and costs while delivering precise hints to selectively isolate bioactive constituents.

Interplay between Inflammation and Pathological Bone Resorption: Insights into Recent Mechanisms and Pathways in Related Diseases for Future Perspectives

Bone is a mineralized and elastic connective tissue that provides fundamental functions in the human body, including mechanical support to the muscles and joints, protection of vital organs and storage of minerals. Bone is a metabolically active organ that undergoes continuous remodeling processes to maintain its architecture, shape, and function throughout life. One of the most important medical discoveries of recent decades has been that the immune system is involved in bone remodeling. Indeed, chronic inflammation has been recognized as the most significant factor influencing bone homeostasis, causing a shift in the bone remodeling process toward pathological bone resorption. Bone osteolytic diseases typified by excessive bone resorption account for one of the greatest causes of disability worldwide, with significant economic and public health burdens. From this perspective, we discuss the recent findings and discoveries highlighting the cellular and molecular mechanisms that regulate this process in the bone microenvironment, in addition to the current therapeutic strategies for the treatment of osteolytic bone diseases.

Efficacy of nanomicelle curcumin, Nigella sativa oil, and their combination on bone turnover markers and their safety in postmenopausal women with primary osteoporosis and osteopenia: A triple-blind randomized controlled trial

Literature supports the potential effects of nanomicelle curcumin and Nigella sativa on the amelioration of osteoporosis, a health concern of postmenopausal women. This study aimed to evaluate the impacts of nanomicelle curcumin (CUR), Nigella sativa oil (NS), and their combination on bone turnover biomarkers and assess their safety. This triple-blind randomized controlled trial was performed on 120 postmenopausal women aged 50-65 with primary osteoporosis or osteopenia. The subjects were randomly allocated to receive microcrystalline cellulose (placebo), 80 mg of CUR, 1000 mg of NS, or their combination (CUR-NS) for 6 months. All patients were also treated with alendronate (70 mg) and calcium (500 mg), vitamin D (400 IU) supplements. The serum levels of alkaline phosphatase (ALP), osteocalcin (OC), and osteopontin (OP) were measured at the baseline and after the intervention. For safety assessment, the hepatic enzyme levels of aspartate transaminase and alanine transaminase as well as serum urea and creatinine were evaluated. ALP levels were significantly reduced in the NS (p = .029) and CUR-NS (p = .015) groups compared with those in the placebo. After adjustment for the covariates, this effect was still significant in the CUR-NS group (p = .004). The OC levels were decreased in the placebo, CUR, and NS groups, and the OP concentration also was attenuated in all groups through the trial. However, the intergroup differences were not significant for both biomarkers. Evaluating the key renal metabolites and hepatic enzyme levels indicated no toxicity of the administered doses. This study reveals the beneficial effects of CUR-NS on the improvement of some bone turnover biomarkers. These compounds seem to be safe at the current dosage for supplementation in postmenopausal women.

Curcumin: The Golden Nutraceutical on the Road to Cancer Prevention and Therapeutics. A Clinical Perspective

Cancer is considered as the major public health scourge of the 21st century. Although remarkable strides were made for developing targeted therapeutics, these therapies suffer from lack of efficacy, high cost, and debilitating side effects. Therefore, the search for safe, highly efficacious, and affordable therapies is paramount for establishing a treatment regimen for this deadly disease. Curcumin, a known natural, bioactive, polyphenol compound from the spice turmeric (Curcuma longa), has been well documented for its wide range of pharmacological and biological activities. A plethora of literature indicates its potency as an anti-inflammatory and anti-cancer agent. Curcumin exhibits anti-neoplastic attributes via regulating a wide array of biological cascades involved in mutagenesis, proliferation, apoptosis, oncogene expression, tumorigenesis, and metastasis. Curcumin has shown a wide range of pleiotropic anti-proliferative effect in multiple cancers and is a known inhibitor of varied oncogenic elements, including nuclear factor kappa B (NF-κB), c-myc, cyclin D1, Bcl-2, VEGF, COX-2, NOS, tumor necrosis factor alpha (TNF-α), interleukins, and MMP-9. Further, curcumin targets different growth factor receptors and cell adhesion molecules involved in tumor growth and progression, making it a most promising nutraceutical for cancer therapy. To date, curcumin-based therapeutics have completed more than 50 clinical trials for cancer. Although creative experimentation is still elucidating the immense potential of curcumin, systematic validation by proper randomized clinical trials warrant its transition from lab to bedside. Therefore, this review summarizes the outcome of diverse clinical trials of curcumin in various cancer types.

High water-soluble curcuminoids-rich extract regulates osteogenic differentiation of MC3T3-E1 cells: Involvement of Wnt/β-catenin and BMP signaling pathway

OBJECTIVE

The present study aimed to evaluate the effect of a high water-soluble curcuminoids-rich extract (CRE) in a solid dispersion form (CRE-SD) using polyvinylpyrrolidone K30 on osteogenic induction of MC3T3-E1 cells.

METHODS

CRE was pre-purified using a microwave assisted extraction couple with a Diaion® HP-20 column chromatography. The osteoblastic cell proliferation and differentiation potentials of CRE-SD in MC3T3-E1 cells were tested by cell viability, alkaline phosphatase (ALP) activity, and Alizarin red S activity assays. The mRNA expressions of osteoblast-specific genes and underline mechanisms were assessed by a real time PCR and western blot analysis.

RESULTS

CRE-SD 50 µg/mL increased alkaline phosphatase (ALP) activity, an early differentiation marker of osteoblasts in both MC3T3-E1 cells and non-osteogenic mouse pluripotent cell line, C3H10T1/2, indicating the action of CRE-SD was not cell-type specific. Alizarin red S activity showed a significant amount of calcium deposition in cells treated with CRE-SD. CRE-SD also upregulated the mRNA expression levels of transcription factors that favor osteoblast differentiation including Bmp-2, Runx2 and Collagen 1a, in a dose dependent manner. Western blot analysis revealed that noggin attenuated CRE-SD-promoted expressions of Bmp-2 and Runx2 proteins. siRNA mediated blocking of Wnt/β-catenin signaling pathway also annulled the influence of CRE-SD, indicating Wnt/β-catenin dependent activity. Inhibition of the different signaling pathways abolished the influence of CRE-SD on ALP activity, confirming that CRE-SD induced MC3T3-E1 cells into osteoblasts through Wnt/β-catenin and BMP signaling pathway.

CONCLUSION

These results collectively demonstrate that CRE-SD may be a potential therapeutic agent for the treatment of osteoporosis.

Human periodontal ligament stem cells and hormesis: Enhancing cell renewal and cell differentiation

This paper provides a detailed assessment of hormetic dose responses by human periodontal ligament stem cells (hPDLSCs). Hormetic dose responses were induced by a broad range of chemicals, including dietary supplements (e.g., curcumin, ginsenoside Rg1), pharmaceutical/commercial substances (e.g., metformin) and endogenous agents (e.g., periostin, TNF-α) for cell proliferation/viability and osteogenic/adipocyte differentiation. This paper clarifies underlying mechanistic foundations of the hPLDSC hormetic dose responses and explores their therapeutic implications. Emerging evidence based on assessments of multiple types of stem cells shows hormetic dose responses to be widespread, reflecting considerable generality and a highly conserved evolutionary trait.

Polyphenols-loaded electrospun nanofibers in bone tissue engineering and regeneration

Bone is a complex structure with unique cellular and molecular process in its formation. Bone tissue regeneration is a well-organized and routine process at the cellular and molecular level in humans through the activation of biochemical pathways and protein expression. Though many forms of biomaterials have been applied for bone tissue regeneration, electrospun nanofibrous scaffolds have attracted more attention among researchers with their physicochemical properties such as tensile strength, porosity, and biocompatibility. When drugs, antibiotics, or functional nanoparticles are taken as additives to the nanofiber, its efficacy towards the application gets increased. Polyphenol is a versatile green/phytochemical small molecule playing a vital role in several biomedical applications, including bone tissue regeneration. When polyphenols are incorporated as additives to the nanofibrous scaffold, their combined properties enhance cell attachment, proliferation, and differentiation in bone tissue defect. The present review describes bone biology encompassing the composition and function of bone tissue cells and exemplifies the series of biological processes associated with bone tissue regeneration. We have highlighted the molecular mechanism of bioactive polyphenols involved in bone tissue regeneration and specified the advantage of electrospun nanofiber as a wound healing scaffold. As the polyphenols contribute to wound healing with their antioxidant and antimicrobial properties, we have compiled a list of polyphenols studied, thus far, for bone tissue regeneration along with their in vitro and in vivo experimental biological results and salient observations. Finally, we have elaborated on the importance of polyphenol-loaded electrospun nanofiber in bone tissue regeneration and discussed the possible challenges and future directions in this field.

Mediterranean Diet Food Components as Possible Adjuvant Therapies to Counteract Breast and Prostate Cancer Progression to Bone Metastasis

Bone metastasis is a serious and often lethal complication of particularly frequent carcinomas, such as breast and prostate cancers, which not only reduces survival but also worsens the patients’ quality of life. Therefore, it is important to find new and/or additional therapeutic possibilities that can counteract the colonization of bone tissue. High adherence to the Mediterranean diet (MD) is effective in the prevention of cancer and improves cancer patients’ health, thus, here, we considered its impact on bone metastasis. We highlighted some molecular events relevant for the development of a metastatic phenotype in cancer cells and the alterations of physiological bone remodeling, which occur during skeleton colonization. We then considered those natural compounds present in MD foods with a recognized role to inhibit or reverse the metastatic process both in in vivo and in vitro systems, and we reported the identified mechanisms of action. The knowledge of this bioactivity by the dietary components of the MD, together with its wide access to all people, could help not only to maintain healthy status but also to improve the quality of life of patients with bone metastases.

Current clinical developments in curcumin-based therapeutics for cancer and chronic diseases

The last decade has seen an unprecedented rise in the prevalence of chronic diseases worldwide. Different mono-targeted approaches have been devised to treat these multigenic diseases, still most of them suffer from limited success due to the off-target debilitating side effects and their inability to target multiple pathways. Hence a safe, efficacious, and multi-targeted approach is the need for the hour to circumvent these challenging chronic diseases. Curcumin, a natural compound extracted from the rhizomes of Curcuma longa, has been under intense scrutiny for its wide medicinal and biological properties. Curcumin is known to manifest antibacterial, antiinflammatory, antioxidant, antifungal, antineoplastic, antifungal, and proapoptotic effects. A plethora of literature has already established the immense promise of curcuminoids in the treatment and clinical management of various chronic diseases like cancer, cardiovascular, metabolic, neurological, inflammatory, and infectious diseases. To date, more than 230 clinical trials have opened investigations to understand the pharmacological aspects of curcumin in human systems. Still, further randomized clinical studies in different ethnic populations warrant its transition to a marketed drug. This review summarizes the results from different clinical trials of curcumin-based therapeutics in the prevention and treatment of various chronic diseases.

The effect of nanomicelle curcumin supplementation and Nigella sativa oil on the expression level of miRNA-21, miRNA-422a, and miRNA-503 gene in postmenopausal women with low bone mass density: A randomized, triple-blind, placebo-controlled clinical trial with factorial design

This study aimed to investigate the effect of nanomicelle curcumin (CUR), Nigella sativa oil (NS), and CUR and NS on the plasma levels of miR-21, miR-422a, and miR-503 expression in postmenopausal women with low bone mass density (BMD). This randomized, triple-blind, placebo-controlled clinical trial with a factorial design was conducted on 120 postmenopausal women from the integrated healthcare system, Tabriz-Iran. The BMD was determined using dual-energy X-ray absorptiometry (DEXA). Women were randomly divided into four groups of 30 participants: (a) CUR (80 mg) and placebo of NS, (b) NS (1,000 mg) and placebo of CUR, (c) CUR (80 mg) and NS (1,000 mg), and (d) both placebos (containing microcrystalline cellulose). The plasma level of miRNA-21, miRNA-422a, and miRNA-503 was determined by qRT-PCR. The expression level of miRNAs at the baseline was similar. At the end of the intervention, only the expression level of miRNA-21 changed statistically significantly between the four groups (p = .037) and between the NS and placebo groups (p = .005). Also, its expression in the two groups receiving NS (p = .037) and NS-CUR (p = .043) was significantly increased. NS and NS-CUR supplementation can increase the expression level of miRNA-21 in postmenopausal women with low bone density, and bring perspective to further studies of the target.

Curcuminoid (CRE-Ter)/Liposome as delivery platform for anti-osteoclastogenesis via NF-κB/ERK pathways in RANKL-induced RAW 264.7 cells through PLA foams

AIMS

Curcuminoid (CRE-Ter) is the active component of turmeric, and is widely understood to offer anticancer, antioxidant, and anti-inflammatory properties. The drawbacks, however, include rapid metabolism and systemic elimination as well as minimal bioavailability. In an attempt to address the issue of bioavailability, this study seeks to encapsulate CRE-Ter in a liposome before its incorporation on PLA foams in order to inhibit the process of osteoclastogenesis which takes place in RANKL-induced RAW 264.7 cells.

MAIN METHODS

Having encapsulated the CRE-Ter into the liposomes, the influence of the release of liposomal CRE-Ter from PLA foams in order to inhibit the process of osteoclastogenesis in the case of RANKL-induced RAW 264.7 cells was investigated. By measuring the decline in tartrate-resistant acid phosphatase (TRAP) content it was possible to evaluate the influence of CRE-Ter/Liposome upon osteoclastogenesis in vitro. Immunocytochemistry was employed to assess the marker for the monocyte/macrophage cells F4/80 content, while Western blots were used to evaluate the underlying mechanisms involved.

KEY FINDINGS

The findings demonstrate a novel method which employs tissue engineering scaffolds, which are produced to work alongside advanced additive manufacturing techniques with their basis in concepts from the field of alternative medicine. Initially, it was confirmed that CRE-Ter/Liposome at 20 μg/ml is able to inhibit the creation of multinucleated osteoclasts which are induced by the receptor activator of the nuclear factor-κB ligand (RANKL) in RAW 264.7 cells. It was shown that the CRE-Ter/liposome was able to increase the F4/80 content (F4/80 immunohistochemistry) in the RANKL treated RAW 264.7 cells. The TRAP content was lowered by the CRE-Ter/liposome along with the osteoclast-specific gene content such as cathepsin K, via the use of liposome-encapsulated PLA foams. When treated with CRE-Ter/liposome, RANKL-induced NF-κB and ERK components such as NF-κB-p65, ERK, phospho-NF-κB-p65, and phospho-ERK pathways were all suppressed.

SIGNIFICANCE

The successful encapsulation of CRE-Ter into the liposomes offered a new opportunity to provide a new inhibitor of osteoclastogenesis and offers the possibility of developing treatments capable of addressing diseases which concern abnormal bone lysis.

Metal-Curcumin Complexes in Therapeutics: An Approach to Enhance Pharmacological Effects of Curcumin

Curcumin, an active component of the rhizome turmeric, has gained much attention as a plant-based compound with pleiotropic pharmacological properties. It possesses anti-inflammatory, antioxidant, hypoglycemic, antimicrobial, neuroprotective, and immunomodulatory activities. However, the health-promoting utility of curcumin is constrained due to its hydrophobic nature, water insolubility, poor bioavailability, rapid metabolism, and systemic elimination. Therefore, an innovative stride was taken, and complexes of metals with curcumin have been synthesized. Curcumin usually reacts with metals through the β-diketone moiety to generate metal–curcumin complexes. It is well established that curcumin strongly chelates several metal ions, including boron, cobalt, copper, gallium, gadolinium, gold, lanthanum, manganese, nickel, iron, palladium, platinum, ruthenium, silver, vanadium, and zinc. In this review, the pharmacological, chemopreventive, and therapeutic activities of metal–curcumin complexes are discussed. Metal–curcumin complexes increase the solubility, cellular uptake, and bioavailability and improve the antioxidant, anti-inflammatory, antimicrobial, and antiviral effects of curcumin. Metal–curcumin complexes have also demonstrated efficacy against various chronic diseases, including cancer, arthritis, osteoporosis, and neurological disorders such as Alzheimer’s disease. These biological activities of metal–curcumin complexes were associated with the modulation of inflammatory mediators, transcription factors, protein kinases, antiapoptotic proteins, lipid peroxidation, and antioxidant enzymes. In addition, metal–curcumin complexes have shown usefulness in biological imaging and radioimaging. The future use of metal–curcumin complexes may represent a new approach in the prevention and treatment of chronic diseases.

Bioactivity and Delivery Strategies of Phytochemical Compounds in Bone Tissue Regeneration

Plant-derived secondary metabolites represent a reservoir of phytochemicals for regenerative medicine application because of their varied assortment of biological properties including anti-oxidant, anti-inflammatory, antibacterial, and tissue remodeling properties. In addition, bioactive phytochemicals can be easily available, are often more cost-effective in large-scale industrialization, and can be better tolerated compared to conventional treatments mitigating the long-lasting side effects of synthetic compounds. Unfortunately, their poor bioavailability and lack of long-term stability limit their clinical impact. Nanotechnology-based delivery systems can overcome these limitations increasing bioactive molecules’ local effectiveness with reduction of the possible side effects on healthy bone. This review explores new and promising strategies in the area of delivery systems with particular emphasis on solutions that enhance bioavailability and/or health effects of plant-derived phytochemicals such as resveratrol, quercetin, epigallocatechin-3-gallate, and curcumin in bone tissue regeneration.

Drug Repositioning for the Treatment of Hematologic Disease: Limits, Challenges and Future Perspectives

Drug repositioning is a strategy to identify new uses for approved or investigational drugs that are used off-label outside the scope of the original medical indication. In this review, we report the most relevant studies about drug repositioning in hematology, reporting the signalling pathways and molecular targets of these drugs, and describing the biological mechanisms which are responsible for their anticancer effects. Although the majority of studies on drug repositioning in hematology concern acute myeloid leukemia and multiple myeloma, numerous studies are present in the literature on the possibility of using these drugs also in other hematological diseases, such as acute lymphoblastic leukemia, chronic myeloid leukemia, and lymphomas. Numerous anti-infectious drugs and chemical entities used for the therapy of neurological or endocrine diseases, oral antidiabetics, statins and medications used to treat high blood pressure and heart failure, bisphosphonate and natural substance such as artemisin and curcumin, have found a place in the treatment of hematological diseases. Moreover, several molecules drastically reversed the resistance of the tumor cells to the chemotherapeutic drugs both in vitro and in vivo.

Natural medicine delivery from biomedical devices to treat bone disorders: A review

With an increasing life expectancy and aging population, orthopedic defects and bone graft surgeries are increasing in global prevalence. Research to date has advanced the understanding of bone biology and defect repair mechanism, leading to a marked success in the development of synthetic bone substitutes. Yet, the quest for functionalized bone grafts prompted the researchers to find a viable alternative that regulates cellular activity and supports bone regeneration and healing process without causing serious side-effects. Recently, researchers have introduced natural medicinal compounds (NMCs) in bone scaffold that enables them to release at a desirable rate, maintains a sustained release allowing sufficient time for tissue in-growth, and guides bone regeneration process with minimized risk of tissue toxicity. According to World Health Organization (WHO), NMCs are gaining popularity in western countries for the last two decades and are being used by 80% of the population worldwide. Compared to synthetic drugs, NMCs have a broader range of safety window and thus suitable for prolonged localized delivery for bone regeneration. There is limited literature focusing on the integration of bone grafts and natural medicines that provides detailed scientific evidences on NMCs, their toxic limits and particular application in bone tissue engineering, which could guide the researchers to develop functionalized implants for various bone disorders. This review will discuss the emerging trend of NMC delivery from bone grafts, including 3D-printed structures and surface-modified implants, highlighting the significance and potential of NMCs for bone health, guiding future paths toward the development of an ideal bone tissue engineering scaffold. STATEMENT OF SIGNIFICANCE: To date, additive manufacturing technology provids us with many advanced patient specific or defect specific bone constructs exhibiting three-dimensional, well-defined microstructure with interconnected porous networks for defect-repair applications. However, an ideal scaffold should also be able to supply biological signals that actively guide tissue regeneration while simultaneously preventing post-implantation complications. Natural biomolecules are gaining popularity in tissue engineering since they possess a safer, effective approach compared to synthetic drugs. The integration of bone scaffolds and natural biomolecules exploits the advantages of customized, multi-functional bone implants to provide localized delivery of biochemical signals in a controlled manner. This review presents an overview of bone scaffolds as delivery systems for natural biomolecules, which may provide prominent advancement in bone development and improve defect-healing caused by various musculoskeletal disorders.

Myostatin Promotes Osteoclastogenesis by Regulating Ccdc50 Gene Expression and RANKL-Induced NF-κB and MAPK Pathways

Myostatin is a crucial cytokine that is widely present in skeletal muscle and that negatively regulates the growth and development of muscle cells. Recent research has shown that myostatin might play an essential role in bone metabolism. In RAW264.7 cells and bone marrow monocytes (BMMCs), myostatin activates the expression of the II type receptor ActR II B. Here, we report that myostatin significantly promoted RANKL/M-CSF-induced osteoclastogenesis and activated NF-κB and MAPK pathways in vitro via the Ccdc50 gene. Overexpression of myostatin promoted osteoclastogenesis and osteoclastogenesis-related markers including c-Src, MMP9, CTR, CK, and NFATc1. Specifically, myostatin increased the phosphorylation of Smad2, which led to the activation of NF-κB and MAPK pathways to activate osteoclastogenesis. Ccdc50 was identified as a gene whose expression was highly decreased in osteoclastogenesis upon myostatin treatment, and it could inhibit the function of myostatin in osteoclastogenesis by blocking NF-κB and MAPKs pathways. Our study indicates that myostatin is a promising candidate target for inhibiting RANKL-mediated osteoclastogenesis and might participate in therapy for osteoporosis, and that the Ccdc50 gene plays a significant role in the regulatory process.

The Effect of Inflammation on Bone

Bone remodeling is the continual process to renew the adult skeleton through the sequential action of osteoblasts and osteoclasts. Nuclear factor RANK, an osteoclast receptor, and its ligand RANKL, expressed on the surface of osteoblasts, result in coordinated control of bone remodeling. Inflammation, a feature of illness and injury, plays a distinct role in skewing this process toward resorption. It does so via the interaction of inflammatory mediators and their related peptides with osteoblasts and osteoclasts, as well as other immune cells, to alter the expression of RANK and RANKL. Such chemical mediators include TNFα, glucocorticoids, histamine, bradykinin, PGE2, systemic RANKL from immune cells, and interleukins 1 and 6. Conditions, such as periodontal disease and alveolar bone erosion, aseptic prosthetic loosening, rheumatoid arthritis, and some sports related injuries are characterized by the result of this process. A thorough understanding of bone response to injury and disease, and ability to detect such biomarkers, as well as imaging to identify early structural and mechanical property changes in bone architecture, is important in improving management and outcomes of bone related pathology. While gut health and vitamin and mineral availability appear vitally important, nutraceuticals also have an impact on bone health. To date most pharmaceutical intervention targets inflammatory cytokines, although strategies to favorably alter inflammation induced bone pathology are currently limited. Further research is required in this field to advance early detection and treatments.

Effect of Pistacia atlantica subsp. kurdica Gum in Experimental Periodontitis Induced in Wistar Rats by Utilization of Osteoclastogenic Bone Markers

The aim of this study was to assess the effect of local application of essential oil of Pistacia atlantica kurdica (EOK) gel in treatment of experimentally induced periodontitis in rats and its effect on osteoclastogenic bone markers. Twenty-four male Wistar rats of 250 to 350 g were used in this study and were allocated into four groups. Control negative (without induced periodontitis), control positive (induced experimental periodontitis left without treatment), treatment control (induced experimental periodontitis and treated with Chlorhexidine gel) and EOK treated group (induced experimental periodontitis treated with EOK gel). The animals were sacrificed after 30 days, and the mandibular central incisor and surrounding tissue were dissected from the mandible and further processed for preparing H&E slides. Inflammatory cells, osteoclast cells, and periodontal ligament (PDL) were examined and measured histologically. Finally, the mean concentrations of both markers, receptor activator of nuclear factor kappa-Β ligand (RANKL) and (Interleukin-1β) IL-1β, were analyzed by ELISA. A significant reduction of inflammatory reaction and osteoclast numbers with improvement of PDL and low mean concentrations of RANKL and IL-1β were seen in the EOK treated group in comparison to the control group and the chlorhexidine group as well. The extract showed a protective effect in the healing of periodontitis that had been induced in rats and decreased bone resorption by down regulation of serum RANKL and IL-1β markers.

Targeted Delivery of Curcumin to Polyethylene-Induced Osteolysis by Magnetically Guided Zoledronate-Anchored Poly Lactic-Co-Glycolic Acid Nanoparticles via Repressing NF-κB Signaling

Aseptic loosening induced by periprosthetic osteolysis (PPO) is the leading complication of total joint arthroplasty (TJA) and results in patients having to receive revision surgery. However, there is still no efficient drug to prevent or even slow the pathological process. Herein, we report novel dual-targeted, curcumin-loaded Poly lactic-co-glycolic acid nanoparticles (ZSCNPs) to inhibit polyethylene-induced osteolysis. These ZSCNPs have good biocompatibility and excellent bone binding affinity. Under external magnetic field guidance, the ZSCNPs can specifically target osteolytic sites with sustained curcumin release, efficiently suppress the effect of IκB kinase, subsequently inhibit activation of the nuclear factor-kappa B (NF-κB) signaling pathway, and ultimately prevent osteoclast formation and particle-induced osteolysis. Therefore, these novel dual-targeted, drug-loaded nanoparticles could be applied as a useful strategy for targeted treatment of PPO after TJA.

Inhibition of Osteoclast Differentiation by Carotenoid Derivatives through Inhibition of the NF-ƙB Pathway

The bone protective effects of carotenoids have been demonstrated in several studies, and the inhibition of RANKL-induced osteoclast differentiation by lycopene has also been demonstrated. We previously reported that carotenoid oxidation products are the active mediators in the activation of the transcription factor Nrf2 and the inhibition of the NF-ƙB transcription system by carotenoids. Here, we demonstrate that lycopene oxidation products are more potent than intact lycopene in inhibiting osteoclast differentiation. We analyzed the structure-activity relationship of a series of dialdehyde carotenoid derivatives (diapocarotene-dials) in inhibiting osteoclastogenesis. We found that the degree of inhibition depends on the electron density of the carbon atom that determines the reactivity of the conjugated double bond in reactions such as Michael addition to thiol groups in proteins. Moreover, the carotenoid derivatives attenuated the NF-ƙB signal through inhibition of IƙB phosphorylation and NF-ƙB translocation to the nucleus. In addition, we show a synergistic inhibition of osteoclast differentiation by combinations of an active carotenoid derivative with the polyphenols curcumin and carnosic acid with combination index (CI) values < 1. Our findings suggest that carotenoid derivatives inhibit osteoclast differentiation, partially by inhibiting the NF-ƙB pathway. In addition, carotenoid derivatives can synergistically inhibit osteoclast differentiation with curcumin and carnosic acid.

Delineating role of NF-κB and interacting cytokines during prostate cancer-induced osteoclastogenesis

Prostate cancer (PCa) frequently metastasizes to the bone leading to devastating complications such as severe pain and fracture. However, the mechanisms by which PCa cells cause bone loss remain less understood. We investigated the role and mechanisms by which PCa cells induce osteoclastogenesis using cultured monocytic osteoclast precursors. Treatment of RAW264.7 cells with PCa cell lines: DU145, LNCaP, PC-3, or their conditioned media led to the formation of distinct multinucleated, TRAP⁺ osteoclasts. This phenomenon was associated with the increased activation of transcription factor nuclear factor-kB (NF-κB). High transcript level of receptor activator of nuclear factor-kB ligand (RANKL), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were detected in PCa cells. TNF-α and LT-α augmented, whereas IL-6 reduced the RANKL-induced osteoclast formation in RAW264.7 cultures. Our results also demonstrated that PCa cells-induced osteoclastogenesis involved the activation of the TRAF6-IKK-p65-NF-κB signaling cascade. Together, our study demonstrates that PCa cells produce RANKL and several other pro-inflammatory cytokines known to influence osteoclastogenesis, by targeting the NF-κB signaling pathway.

Irisin directly stimulates osteoclastogenesis and bone resorption in vitro and in vivo

Irisin, a skeletal-muscle secreted myokine, facilitates muscle-bone crosstalk and skeletal remodeling in part by its action on osteoblasts and osteocytes. In this study, we investigated whether irisin directly regulates osteoclasts. In vitro, irisin (2-10 ng/mL) increased osteoclast differentiation in C57BL/6J mouse bone marrow progenitors; however, this increase was blocked by a neutralizing antibody to integrin αVβ5. Irisin also increased bone resorption on several substrates in situ. RNAseq revealed differential gene expression induced by irisin including upregulation of markers for osteoclast differentiation and resorption, as well as osteoblast-stimulating 'clastokines'. Forced expression of the irisin precursor Fndc5 in transgenic C57BL/6J mice resulted in lower bone mass at three ages and greater in vitro osteoclastogenesis from Fndc5-transgenic bone marrow progenitors. This study demonstrates that irisin acts directly on osteoclast progenitors to increase differentiation and promote bone resorption, supporting the tenet that irisin not only stimulates bone remodeling but may also be an important counter-regulatory hormone.

GSH attenuates RANKL-induced osteoclast formation in vitro and LPS-induced bone loss in vivo

Osteoclasts are capable of adhering the bone matrix, then secrete acid and lytic enzymes to resorb it. Reactive oxygen species (ROS), as a signaling messenger, plays an important role in the receptor activator nuclear factor κB ligand (RANKL) signal pathway during osteoclast differentiation. Glutathione (GSH) is known to be a powerful antioxidant which can scavenge intracellular ROS. This study aimed to investigate whether GSH can as a protective agent against the RANKL-stimulated osteoclastogenesis by suppressing intracellular ROS. Here, we showed that GSH markedly restricted RNAKL-induced differentiation of bone marrow-derived macrophages (BMMs) to form osteoclasts. GSH suppressed RANKL-induced ROS generation and subsequent ROS-induced NF-κB signaling pathways within BMMs during osteoclastogenesis. Further, GSH acted to significantly downregulate the osteoclastogenic genes expression of nuclear factor in activated T cells, cytoplasmic1 (NFATc1), C-fos, the tartrate-resistant acid phosphatase (TRAP), and osteoclast-associated immunoglobulin-like receptor (OSCAR). Our results suggested that GSH inhibits intracellular ROS-mediated NF-κB signal pathway involved in osteoclast differentiation. These findings might form the basis of a new strategy for treating bone disease associated with excessive bone resorption.

Curcumin-crosslinked acellular bovine pericardium for the application of calcification inhibition heart valves

Glutaraldehyde (GA) crosslinked bovine or porcine pericardium tissues exhibit high cell toxicity and calcification in the construction of bioprosthetic valves, which accelerate the failure of valve leaflets and motivate the exploration for alternatives. Polyphenols, including curcumin, procyanidin and quercetin, etc, have showed great calcification inhibition potential in crosslinking collagen and elastin scaffolds. Herein, we developed an innovative phenolic fixing technique by using curcumin as the crosslinking reagent for valvular materials. X-ray photoelectron spectroscopy and Fourier transform infrared spectrometry assessments confirmed the hydrogen bond between curcumin and acellular bovine pericardium. Importantly, the calcification inhibition capability of the curcumin-crosslinked bovine pericardium was proved by the dramatically reduced Ca²⁺ content in the curcumin-fixed group in in vitro assay, a juvenile rat subcutaneous implants model, as well as an osteogenic differentiation model. In addition, the results showed that the curcumin-fixed bovine pericardium exhibited better performance in the areas of mechanical performance, hemocompatibility and cytocompatibility, in comparison with the GA group and the commercialized product. In summary, we demonstrated that curcumin was a feasible crosslinking reagent to fix acellular bovine pericardium, which showed great potential for biomedical applications, particularly in cardiovascular biomaterials with calcification inhibition capacity.

Natural Medicinal Compounds in Bone Tissue Engineering

Recent advances in 3D printing have provided unprecedented opportunities in bone tissue engineering applications for producing a variety of complex patient-specific implants for the treatment of critical-sized bone defects. Natural medicinal compounds (NMCs) with osteogenic potential can be incorporated into these 3D-printed parts to improve bone formation and therefore enhance implant performance. Using NMCs to treat bone-related disorders may prove to be a healthy preventive choice as they are considered safe, have lesser or no side effects, and are more suitable for prolonged use than synthetic drugs. In this review paper, the current challenges of bone tissue engineering are addressed briefly, highlighting the immense potential of NMCs integrated within tissue engineering scaffolds for orthopedic and dental applications.

Impact of Natural Dietary Agents on Multiple Myeloma Prevention and Treatment: Molecular Insights and Potential for Clinical Translation

Chemoprevention is based on the use of non-toxic, pharmacologically active agents to prevent tumor progression. In this regard, natural dietary agents have been described by the most recent literature as promising tools for controlling onset and progression of malignancies. Extensive research has been so far performed to shed light on the effects of natural products on tumor growth and survival, disclosing the most relevant signal transduction pathways targeted by such compounds. Overall, anti-inflammatory, anti-oxidant and cytotoxic effects of dietary agents on tumor cells are supported either by results from epidemiological or animal studies and even by clinical trials. Multiple myeloma is a hematologic malignancy characterized by abnormal proliferation of bone marrow plasma cells and subsequent hypercalcemia, renal dysfunction, anemia, or bone disease, which remains incurable despite novel emerging therapeutic strategies. Notably, increasing evidence supports the capability of dietary natural compounds to antagonize multiple myeloma growth in preclinical models of the disease, underscoring their potential as candidate anti-cancer agents. In this review, we aim at summarizing findings on the anti-tumor activity of dietary natural products, focusing on their molecular mechanisms, which include inhibition of oncogenic signal transduction pathways and/or epigenetic modulating effects, along with their potential clinical applications against multiple myeloma and its related bone disease.