Bisphosphonates: focus on inflammation and bone loss

Structural characterization and osteogenic differentiation-promoting activity of polysaccharide purified from Chroogomphus rutilus

Chroogomphus rutilus (CR) possesses anti-inflammatory, antioxidant, and hypoglycemic properties. However, studies are yet to evaluate the anti-osteoporotic activity of the fungi and its polysaccharides. Therefore, this study is aimed at characterizing and evaluating the anti-osteoporotic effects of a novel polysaccharide from CR. The neutral polysaccharide CRP2 extracted and purified from the fruiting body of CR had a molecular weight of 20.41 kDa. Monosaccharide composition analysis revealed that CRP2 is composed of galactose, glucose, fucose, and mannose. The backbone of CRP2 primarily consisted of →6)-α-D-Galp-(1 → residues, with specific site substitutions speculated at partial positions, such as O-CH3 substitution at H-3 position, or a branch site located at C-2, including α-L-Fucp-(1 → 6)-β-D-Glcp-(1 → and α-D-Manp-(1→. CRP2 treatment increased trabecular bone density, restored a network-shaped structure, and upregulated the expression of osteoblast differentiation markers, including runt-related transcription factor 2, osterix, osteocalcin, and osteopontin in the femoral tissue of mice with osteoporosis (OP). Additionally, CRP2 treatment suppressed the expression of tumor necrosis factor-α and interleukin-1β in the femoral tissue of mice with OP. Mechanistically, CRP2 exerted anti-OP effect by inhibiting inflammation and promoting osteogenesis through the transforming growth factor β-1/Smad pathway. Conclusively, these findings augment our understanding of the potential role of CRP2 in OP treatment.

Nanoparticle-Based Drug Delivery Systems for Enhancing Bone Regeneration

The treatment of bone defects has been a long-standing challenge in clinical practice. Among the various bone tissue engineering approaches, there has been substantial progress in the development of drug delivery systems based on functional drugs and appropriate carrier materials owing to technological advances in recent years. A large number of materials based on functional nanocarriers have been developed and applied to improve the complex osteogenic microenvironment, including for promoting osteogenic activity, inhibiting osteoclast activity, and exerting certain antibacterial effects. This Review discusses the physicochemical properties, drug loading mechanisms, advantages and disadvantages of nanoparticles (NPs) used for constructing drug delivery systems. In addition, we provide an overview of the osteogenic microenvironment regulation mechanism of drug delivery systems based on nanoparticle (NP) carriers and the construction strategies of drug delivery systems. Finally, the advantages and disadvantages of NP carriers are summarized along with their prospects and future research trends in bone tissue engineering. This Review thus provides advanced strategies for the design and application of drug delivery systems based on NPs in the treatment of bone defects.

Subtypes of complex regional pain syndrome-a systematic review of the literature

To systematically identify and summarize possible subtypes of complex regional pain syndrome (CRPS), we searched MEDLINE, Embase, Cochrane, Scopus, and Web of Science for original studies reporting or investigating at least one subtype within a group of patients with CRPS. The search retrieved 4239 potentially relevant references. Twenty-five studies met our inclusion criteria and were included in the analysis. Complex regional pain syndrome phenotypes were investigated based on the following variables: clinical presentation/sensory disturbances, dystonia, skin temperature, disease duration, onset type, CRPS outcome, and neuropsychological test performance. Support was found for the following CRPS subtypes: CRPS type I, CRPS type II, acute CRPS, chronic CRPS, centralized CRPS, cold CRPS, warm CRPS, inflammatory CRPS, dystonic CRPS, nondystonic CRPS, familial CRPS, and nonfamilial CRPS. It is unclear whether these are distinct or overlapping subtypes. The results of this comprehensive review can facilitate the formulation of well-defined CRPS subtypes based on presumed underlying mechanisms. Our findings provide a foundation for establishing and defining clinically meaningful CRPS subtypes, with the ultimate goal of developing targeted and enhanced treatments for CRPS.

Targeting chronic inflammation as a potential adjuvant therapy for osteoporosis

Systemic, chronic, low-grade inflammation (SCLGI) underlies the pathogenesis of various widespread diseases. It is often associated with bone loss, thus connecting chronic inflammation to the pathogenesis of osteoporosis. In postmenopausal women, osteoporosis is accompanied by SCLGI development, likely owing to estrogen deficiency. We propose that SCGLI persistence in osteoporosis results from failed inflammation resolution, which is mainly mediated by specialized, pro-resolving mediators (SPMs). In corroboration, SPMs demonstrate encouraging therapeutic effects in various preclinical models of inflammatory disorders, including bone pathology. Since numerous data implicate gut dysbiosis in osteoporosis-associated chronic inflammation, restoring balanced microbiota by supplementing probiotics and prebiotics could contribute to the efficient resolution of SCGLI. In the present review, we provide evidence for this hypothesis and argue that efficient SCGLI resolution may serve as a novel approach for treating osteoporosis, complementary to traditional anti-osteoporotic medications.

Bisphosphonates, Bone and Joint Pain

PURPOSE OF REVIEW

Bisphosphonates (BPs) have an established role in a number of diseases including osteoporosis, but the role of BPs for treating symptomatic conditions other than bone metastases is less clear. We review recent data on the efficacy of BPs in the treatment of symptomatic bone and joint pain with osteoarthritis (OA) as an example.

RECENT FINDINGS

Although controversial, BPs have been reported to improve pain ratings, imaging features, and inflammatory markers in patients with arthritis, more specifically OA. It is possible that their effects in periarticular bone strongly influence the complex inflammatory process within the joints. Recent data also suggests that they can potentially impact synovial and synoviocytes and macrophages. Although more studies are needed to define their contribution in clinical practice, increasing evidence suggests they hold an important function, especially in conditions with periarticular bone involvement such as OA. Although BPs are indicated primarily for prevention and treatment of osteoporosis, they can also have potential effects on the inflammatory process of other conditions, including OA. Improvements in pain scale ratings, periarticular findings through imaging, and inflammatory response suggest their potential extra-osteoporotic properties.

Topical Nano-Vesicular Spanlastics of Celecoxib: Enhanced Anti-Inflammatory Effect and Down-Regulation of TNF-α, NF-кB and COX-2 in Complete Freund's Adjuvant-Induced Arthritis Model in Rats

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease that underlies chronic inflammation of the synovial membrane. Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat RA. However, a long list of adverse events associated with long-term treatment regimens with NSAIDs negatively influences patient compliance and therapeutic outcomes.

AIM

The aim of this work was to achieve site-specific delivery of celecoxib-loaded spanlastic nano-vesicle-based delivery system to the inflamed joints, avoiding systemic administration of large doses.

METHODOLOGY

To develop spanlastic nanovesicles for transdermal delivery of celecoxib, modified injection method was adopted using Tween 80 or Brij as edge activators. Entrapment efficiency, vesicle size, ex vivo permeation, and morphology of the prepared nano-vesicles were characterized. Carbopol-based gels containing the selected formulations were prepared, and their clarity, pH, rheological performance, and ex vivo permeation were characterized. Celecoxib-loaded niosomes and noisome-containing gels were developed for comparison. The in vivo efficacy of the selected formulations was evaluated in a rat model of Freund's complete adjuvant-induced arthritis. Different inflammatory markers including TNF-α, NF-кB and COX-2 were assessed in paw tissue before and after treatment.

RESULTS

The size and entrapment efficiency of the selected spanlastic nano-vesicle formulation were 112.5 ± 3.6 nm, and 83.6 ± 2.3%, respectively. This formulation has shown the highest transdermal flux and permeability coefficient compared to the other investigated formulations. The spanlastics-containing gel of celecoxib has shown transdermal flux of 6.9 ± 0.25 µg/cm2/hr while the celecoxib niosomes-containing gel and unprocessed celecoxib-loaded gel have shown 5.2 ± 0.12 µg/cm2/hr and 0.64 ± 0.09 µg/cm2/hr, respectively. In the animal model of RA, the celecoxib-loaded spanlastics-containing gel significantly reduced edema circumference and significantly suppressed TNF-α, NF-кB and COX-2 levels compared to the niosomes-containing gel, the marketed diclofenac sodium gel, and unprocessed celecoxib-loaded gel.

CONCLUSION

The spanlastic nano-vesicle-containing gel represents a more efficient site-specific treatment for topical treatment of chronic inflammation like RA, compared to commercial and other conventional alternatives.

Structure-Dependent Effects of Bisphosphonates on Inflammatory Responses in Cultured Neonatal Mouse Calvaria

Bisphosphonates (BPs) are classified into two groups, according to their side chain structures, as nitrogen-containing BPs (NBPs) and non-nitrogen-containing BPs (non-NBPs). In this study, we examined the effects of NBPs and non-NBPs on inflammatory responses, by quantifying the inflammatory mediators, prostaglandin E₂ (PGE₂) and nitric oxide (NO), in cultured neonatal mouse calvaria. All examined NBPs (pamidronate, alendronate, incadronate, risedronate, zoledronate) stimulated lipopolysaccharide (LPS)-induced PGE₂ and NO production by upregulating COX-2 and iNOS mRNA expression, whereas non-NBPs (etidronate, clodronate, tiludronate) suppressed PGE₂ and NO production, by downregulating gene expression. Additionally, [4-(methylthio) phenylthio] methane bisphosphonate (MPMBP), a novel non-NBP with an antioxidant methylthio phenylthio group in its side chain, exhibited the most potent anti-inflammatory activity among non-NBPs. Furthermore, results of immunohistochemistry showed that the nuclear translocation of NF-κB/p65 and tyrosine nitration of cytoplasmic protein were stimulated by zoledronate, while MPMBP inhibited these phenomena, by acting as a superoxide anion (O₂⁻) scavenger. These findings indicate that MPMBP can act as an efficacious agent that causes fewer adverse effects in patients with inflammatory bone diseases, including periodontitis and rheumatoid arthritis.

Corticosteroid transdermal delivery significantly improves arthritis pain and functional disability

Arthritis is characterized by pain and functional limitation affecting the patients' quality of life. We performed a clinical study to investigate the efficacy of a betamethasone valerate medicated plaster (Betesil) in improving pain and functional disability in patients with arthritis and osteoarthritis. We enrolled 104 patients affected by osteoarthritis (n = 40) or arthritis (n = 64) in different joints. Patients received diclofenac sodium cream (2 g, four times a day) or a 2.25-mg dose of Betesil applied to the painful joint every night before bedtime for 10 days. Pain and functional disability were assessed, by the Visual Analogue Scale (VAS) and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) scores. Redness was assessed by clinical inspection, and edema by the "fovea sign" method. C-reactive protein (CRP) was also measured; CRP can be used to cost-effectively monitor the pharmacological treatment efficacy and is increased during the acute-phase response, returning to physiological values after tissue recovery and functional restoration. All measurements were at baseline and at 10-day follow-up. At 10-day follow-up, a greater improvement in VAS and WOMAC pain and WOMAC stiffness and functional limitation scores from baseline was observed in patients treated with Betesil compared with diclofenac (all p < 0.01). At 10-day follow-up, improvement in redness, edema, and CRP levels from baseline was also greater in patients treated with Betesil compared with diclofenac (all p < 0.01). This study demonstrates the safety and efficacy of transdermal delivery of betamethasone valerate in patients affected by arthritis and osteoarthritis.

Osteoblast as a target of anti-osteoporotic treatment

Osteoblasts are mesenchymal cells that play a key role in maintaining bone homeostasis; they are responsible for the production of extracellular matrix proteins, regulation of matrix mineralization, control of bone remodeling and regulate osteoclast differentiation. Osteoblasts have an essential role in the pathogenesis of many bone diseases, particularly osteoporosis. For many decades, the main current available treatments for osteoporosis have been represented by anti-resorptive drugs, such as bisphosphonates, which act mainly by inhibiting osteoclasts maturation, proliferation and activity; nevertheless, in recent years much attention has been paid on anabolic aspects of osteoporosis treatment. Many experimental evidences support the hypothesis of direct effects of the classical anti-resorptive drugs also on osteoblasts, and recent progress in understanding bone physiology have led to the development of new pharmacological agents such as anti-sclerostin antibodies and teriparatide which directly target osteoblasts, inducing anabolic effects and promoting bone formation.

An Update on the Pathogenesis and Treatment of Chronic Recurrent Multifocal Osteomyelitis in Children

Chronic recurrent multifocal osteomyelitis (CRMO), also known as chronic non-bacterial osteomyelitis (CNO), is a rare inflammatory disorder that primarily affects children. It is characterized by pain, local bone expansion, and radiological findings suggestive of osteomyelitis, usually at multiple sites. CRMO predominantly affects the metaphyses of long bones, but involvement of the clavicle or mandible are suggestive of the diagnosis. CRMO is a diagnosis of exclusion, and its pathogenesis remains unknown. Differential diagnosis includes infection, malignancies, benign bone tumors, metabolic disorders, and other autoinflammatory disorders. Biopsy of the bone lesion is not often required but could be necessary in unclear cases, especially for differentiation from bone neoplasia. Non-steroidal anti-inflammatory drugs (NSAIDs) are the first-line treatment. Alternative therapies have been used, including corticosteroids, methotrexate, bisphosphonates, and tumor necrosis factor (TNF)-α inhibitors. No guidelines have been established regarding diagnosis and treatment options. This manuscript gives an overview of the most recent findings on the pathogenesis of CRMO and clinical approaches for patients with the condition.

Regulation of the differentiation of osteoblasts and osteoclasts by a hot-water extract of adzuki beans (Vigna angularis)

Osteoporosis is a global public health problem thought to be caused by an imbalance in bone metabolism. We examined in this study the 40% ethanol fraction of HP-20 resin in combination with a hot-water adzuki extract (EtEx.40) for its effect on osteoblast and osteoclast differentiation. EtEx.40-treated murine preosteoblast MC3T3-E1 cells exhibited significantly elevated alkaline phosphatase activity and mineralization. EtEx.40 facilitated osteoblast differentiation by up-regulating such osteoblast differentiation-related molecules as runt-related transcription factor 2, distal-less homeobox 5, and osterix via p38 mitogen-activated protein kinase. EtEx.40 also suppressed the formation of large tartrate-resistant acid phosphatase-positive multinucleated cells in RAW264.7 cells that had been stimulated with the receptor activator of the nuclear factor κB ligand/macrophage colony-stimulating factor. EtEx.40 significantly inhibited NF-κB activation, thus reducing the expression of such downstream molecules as c-Fos and NFATc1. Our findings suggest that EtEx.40 could be used to maintain bone mass.

Pulsed electromagnetic field therapy for management of osteoarthritis-related pain, stiffness and physical function: clinical experience in the elderly

BACKGROUND

Pulsed electromagnetic field (PEMF) therapy has shown promising therapeutic effectiveness on bone- and cartilage-related pathologies, being also safe for management of knee osteoarthritis.

AIM

The aim of this study was to investigate the clinical efficacy of a PEMF device for management of knee osteoarthritis in elderly patients.

MATERIALS AND METHODS

A total of 33 patients were screened, and 28 patients, aged between 60 and 83 and affected by bilateral knee osteoarthritis, were enrolled in this study. They received PEMF therapy on the right leg for a total of three 30-minute sessions per week for a period of 6 weeks, while the left leg did not receive any treatment and served as control. An intravenous drip containing ketoprofen, sodium clodronate, glucosamine sulfate, calcitonin, and ascorbic acid, for a total volume of 500 mL, was administered during PEMF therapy. At baseline and 3 months post-PEMF therapy, Visual Analog Scale (VAS) was used to assess knee pain and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) was used to measure knee pain, stiffness and physical function.

RESULTS

Changes in VAS and WOMAC scores were calculated for both knees as baseline minus post-treatment. A two sample Student's t-test, comparing change in knee-related VAS pain for PEMF-treated leg (49.8 ± 2.03) vs control leg (11 ± 1.1), showed a significant difference in favor of PEMF therapy (P < 0.001). A two sample Student's t-test comparing change in knee-related WOMAC pain, stiffness, and physical function for PEMF-treated leg (8.5 ± 0.4, 3.5 ± 0.2, 38.5 ± 2.08, respectively) vs control leg (2.6 ± 0.2; 1.6 ± 0.1; 4.5 ± 0.5 respectively), also showed a significant difference in favor of PEMF therapy (P < 0.001). No adverse reactions to therapy were observed.

CONCLUSION

The present study shows that PEMF therapy improves pain, stiffness and physical function in elderly patients affected by knee osteoarthritis.

Preliminary study of highly cross-linked hyaluronic acid-based combination therapy for management of knee osteoarthritis-related pain

Background

Hyaluronic acid has been extensively used for treatment of knee osteoarthritis due to its anti-inflammatory properties and its ability to act as a synovial lubricant. Furthermore, it has found application in combination with other drugs in the dermatological field and in pre-clinical studies in animal models of osteoarthritis. Experimental evidence suggests that a combination of this macromolecule with other drugs may act as a slow-release depot. However, to date, to the best of our knowledge, no one has tested local intra-articular delivery of highly cross-linked hyaluronic acid combined with bisphosphonate or nonsteroidal anti-inflammatory drugs for management of knee osteoarthritis pain in the clinical setting. The aim of the present randomized double-blind study was to investigate, for the first time, the effect of a highly cross-linked hyaluronic acid, Variofill^®, alone or in combination with diclofenac sodium or sodium clodronate, for management of bilateral knee osteoarthritis-related pain.

Methods

Sixty-two patients with symptomatic bilateral medial tibiofemoral knee osteoarthritis (Kellgren–Lawrence grade II and III) and pain in both knees corresponding to a daily visual analog scale (VAS) score ≥ 30 in the month before the beginning of the study were included in this investigation. Patients were divided into three groups: group 1, treated with an injection of hyaluronic acid alone (66 mg) into each knee; group 2, treated with an injection of hyaluronic acid (49.5 mg) plus diclofenac sodium (5 mg) into each knee; group 3, treated with an injection of hyaluronic acid (49.5 mg) plus sodium clodronate (5 mg) into each knee. Patients also underwent blood tests for measurement of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) immediately before and at 6-month follow-up.

Results

Hyaluronic acid alone and in combination with sodium clodronate or diclofenac sodium produced a significant improvement in mean VAS pain score at 3 and 6-month follow-up. At 6-month follow-up, therapy with hyaluronic acid plus sodium clodronate was the most beneficial in terms of percentage improvement in VAS pain score. A significant improvement in ESR and CRP was observed at 6-month follow-up in each treatment group. No significant difference was observed when the percentage change from baseline related to these parameters was compared among the groups. No dropout was observed in any group. No serious adverse events were observed.

Conclusion

Further studies are necessary to determine the effect of a therapy based on hyaluronic acid combined with diclofenac sodium or sodium clodronate in larger cohorts of patients affected by knee osteoarthritis and in longer-term follow-up.

Potential antiosteoporotic agents from plants: a comprehensive review

Osteoporosis is a major health hazard and is a disease of old age; it is a silent epidemic affecting more than 200 million people worldwide in recent years. Based on a large number of chemical and pharmacological research many plants and their compounds have been shown to possess antiosteoporosis activity. This paper reviews the medicinal plants displaying antiosteoporosis properties including their origin, active constituents, and pharmacological data. The plants reported here are the ones which are commonly used in traditional medical systems and have demonstrated clinical effectiveness against osteoporosis. Although many plants have the potential to prevent and treat osteoporosis, so far, only a fraction of these plants have been thoroughly investigated for their physiological and pharmacological properties including their mechanism of action. An attempt should be made to highlight plant species with possible antiosteoporosis properties and they should be investigated further to help with future drug development for treating this disease.