Disease-modifying therapies for osteoarthritis : current status

The pro-inflammatory cytokine IL-Iβ alteration by deer (Rusa unicolor) antler extract on osteoarthritis rat model

Osteoarthritis is a disease associated with articular cartilage degradation, intra-articular area inflammation, and subchondral bone replacement. Cytokine IL-1β has a prominent function in the inflammations process that passes in the joints. The 70% ethanol extracts of deer antler (250 and 500 mg/kg BW) and glucosamine sulfate (250 kg/BW) were evaluated for four weeks in reducing cytokine IL-1β to rat model OA-induced Monosodium iodoacetate. Measurements of joint diameter in rat's knee and hyperalgesia were performed on weeks 0, 1, 2, 3, 4, 5, 6, and 7. The presence of a significant difference in the stimulation thermal latency (p = 0.00) and the resulting increase in swelling of joint diameter (p = 0.00) are evidence that MIA has successfully induced the rat modeling of OA. A significant decrease in cytokine IL-Iβ levels was shown on week 3 after MIA injection (p = 0.00). Both concentrations of deer extracts significantly reduced knee joint diameter (p = 0.00), latency thermal stimulation (p = 0.00), and cytokine IL-1β levels (p = 0.00). Based on the results, it can be concluded that the 70% ethanol extract of deer antler is a potential medicine for OA therapy.

Astragaloside IV as a novel CXCR4 antagonist alleviates osteoarthritis in the knee of monosodium iodoacetate-induced rats

BACKGROUND AND PURPOSE

C-X-C chemokine receptor type 4 (CXCR4) inhibition protects cartilage in osteoarthritis (OA) animal models. Therefore, CXCR4 has becoming a novel target for OA drug development. Since dietary and herbal supplements have been widely used for joint health, we hypothesized that some supplements exhibit protective effects on OA cartilage through inhibiting CXCR4 signaling.

METHODS

The single-cell RNA sequencing data of OA patients (GSE152805) was re-analyzed by Scanpy 1.9.0. The docking screening of CXCR4 antagonists was conducted by Autodock Vina 1.2.0. The CXCR4 antagonistic activity was evaluated by calcium response in THP-1 cells. Signaling pathway study was conducted by bulk RNA sequencing and western blot analysis in human C28/I2 chondrocytes. The anti-OA activity was evaluated in monosodium iodoacetate (MIA)-induced rats.

RESULTS

Astragaloside IV (ASN IV), the predominate phytochemical in Astragalus membranaceus, has been identified as a novel CXCR4 antagonist. ASN IV reduced CXCL12-induced ADAMTS4,5 overexpression in chondrocytes through blocking Akt signaling pathway. Furthermore, ASN IV administration significantly repaired the damaged cartilage and subchondral bone in MIA-induced rats.

CONCLUSION

The blockade of CXCR4 signaling by ASN IV could explain anti-OA activities of Astragalus membranaceus by protection of cartilage degradation in OA patients. Since ASN IV as an antiviral has been approved by China National Medical Products Administration for testing in people, repurposing of ASN IV as a joint protective agent might be a promising strategy for OA drug development.

Ginsenoside-Rb1 prevents bone cartilage destruction through down-regulation of p-Akt, p-P38, and p-P65 signaling in rabbit

BACKGROUND

Osteoarthritis (OA) is the most common joint complaint resulting in pain, disability, and loss of quality of life. On the other hand, ginsenoside-Rb1 is a plant product derived from ginseng that possesses immune-regulation and anti-inflammatory activities. However, it has been reported that different rout of administration but hydrogel-based Ginsenoside-Rb1 in an OA rabbit model has not been investigated.

PURPOSE

The aim of this study was to investigate the potential effects of ginsenoside-Rb1 such as anti-arthritic activity in a rabbit knee OA model via NF- κB, PI3K/Akt, and P38/(MAPK) pathways.

STUDY DESIGN

In the current study, rabbit osteoarthritis was induced by hollow trephine on the femur trochlea and the hydrogel-based Ginsenoside-Rb1 sheets were inserted on the rabbit knee to assess the anti-arthritis activity of ginsenoside-Rb1 which is sustained release.

METHODS

After the hydrogel-based Rb1 sheet insert on the rabbit knee, macroscopic and micro CT was performed for investigation of chondroprotective effect. Matrix metalloproteinases (MMPs) and apoptotic expression were assessed through Immunohistochemistry and RT-PCR assay. In addition, the flow cytometry technique was used for the investigation of intracellular reactive oxygen species (ROS) production and histological changes were examined by HE, safranin O, and Masson trichrome staining method. Furthermore, the NF- κB, PI3K/Akt, and P38/(MAPK) pathways were investigated using Western blot analysis.

RESULTS

Macroscopic and micro CT investigation of hydrogel-Rb1 treatment showed a dose-dependent chondroprotective effect. Immunohistochemistry and RT-PCR revealed that expression of matrix metalloproteinases (MMPs) and apoptotic markers TNF-α, caspase-3, and bax are down-regulated in a dose-dependent fashion following implantation of hydrogel-Rb. Higher levels of intracellular reactive oxygen species (ROS) were observed in the OA group. In histopathological investigation of hydrogel-Rb1 exhibited larger amounts of chondro cells, glycosaminoglycan's, and collagen compared to the defect group. Furthermore, the NF- κB, PI3K/Akt, and P38/(MAPK) pathways were downregulated by hydrogel-Rb1 while the disease model showed upstream. In the meantime, MMP expression level was considerably down-regulated.

CONCLUSIONS

Our results indicate the protective effect of ginsenoside-Rb1 against OA pathogenesis through prevention of apoptosis with suppression of ROS production and activation of NF-κB signaling through downregulation of the MAPK and PI3K/Akt signaling pathways.

Single intra-articular injection with or without intra-osseous injections of platelet-rich plasma in the treatment of osteoarthritis knee: A single-blind, randomized clinical trial

BACKGROUND

Subchondral bony structure damage plays an essential role in the pathogenesis of osteoarthritis (OA) knee. An intra-articular injection cannot reach the damaged subchondral bony structure and treat its pathologies effectively. The objective of the study was to compare the clinical effects of single intra-articular injection with or without intra-osseous injections of PRP in the treatment of osteoarthritis (OA) knee.

METHODS

This was a single-blind, parallel-group, randomized clinical trial. Fifty patients, with OA knee (K&L grade III), with ages between 50 and 65 years, were randomly allocated into 'intra-osseous, intra-articular PRP' ('IO+IA-PRP') (n = 25) or 'intra-articular PRP' group ('IA-PRP') (n = 25). Patients in the 'IO+IA-PRP' group received 18 ml PRP injection, and the 'IA-PRP' group received 8 ml PRP injection. Intra-osseous injections were given at the tibial plateau (5 ml) and femoral condyle (5 ml), along with intra-articular knee injection (8 ml), under fluoroscopic guidance. Outcomes were measured using VAS-pain, the knee injury and osteoarthritis outcome score (KOOS), and the treatment satisfaction scale. All patients (n = 50) were followed up till six months.

RESULTS

The mean age was 57.12(4.27) years and 57.00(4.96) years in the 'IO+IA-PRP' and 'IA-PRP' groups. Both groups showed significant improvement in pain relief (VAS pain) and KOOS parameters: pain, symptoms, ADL function, sport and recreation function, and quality of life. Compared to the 'IA-PRP' group, the 'IO+IA-PRP' group showed a greater reduction of VAS pain at six months. However, no significant difference was obtained in VAS pain-relief between these two groups (p = 0.422) at six months. Similarly, at 6 months, in inter-group comparison, except 'sport and recreation function' (p < 0.05), no significant differences were obtained in mean-scores of KOOS parameters: pain (p = 0.514); symptom (p = 0.148), ADL-function (p = 0.991), QoL-(p = 0.376). Patients in the 'IO+IA-PRP' group complained of significant 'injection-associated' adverse events and consumed a greater number of Acetaphenomen.

CONCLUSIONS

Both groups showed significant improvement following the intervention. Intra-osseous PRP injections did not provide any additional benefit over intra-articular PRP injection until six months regarding pain relief and functional improvement.

Nutraceutical Approach to Chronic Osteoarthritis: From Molecular Research to Clinical Evidence

Osteoarthritis (OA) is a degenerative inflammatory condition of the joint cartilage that currently affects approximately 58 million adults in the world. It is characterized by pain, stiffness, and a reduced range of motion with regard to the arthritic joints. These symptoms can cause in the long term a greater risk of overweight/obesity, diabetes mellitus, and falls and fractures. Although the current guidelines for the treatment of OA suggest, as the gold standard for this condition, pharmacological treatment characterized by non-steroidal anti-inflammatory drugs (NSAID), opioids, and cyclooxygenase (COX)-2-specific drugs, a great interest has been applied to nutraceutical supplements, which include a heterogeneous class of molecules with great potential to reduce inflammation, oxidative stress, pain, and joint stiffness and improve cartilage formation. The purpose of this review is to describe the potential application of nutraceuticals in OA, highlighting its molecular mechanisms of actions and data of efficacy and safety (when available).

The Identified Hub Gene GlcN in Osteoarthritis Progression and Treatment

BACKGROUND

As a chronic disease, osteoarthritis has caused great trouble to the health of middle-aged and elderly people. Studies have shown that glucosamine (GlcN) can be used to abate the progression and improve this disease. Based on this point of view, we try to verify the connection between GlcN and osteoarthritis and find more effective biomarkers.

METHODS

We downloaded the GSE72575 data set from the GEO database, and used the R language to perform DEG analysis on the gene expression profile of the samples. Next, the GO function and the KEGG signaling pathways were analyzed through the DAVID database, and then, the KEGG pathways enriched in the gene set were analyzed based on GSEA. Then, the PPI network of DEGs was constructed based on the STRING online database, and finally, the hub genes were selected by Cytoscape.

RESULTS

Three GlcN-treated MH7A cell treatment groups and 3 control groups in the GSE72575 data set were studied. Through analysis, there were 52 DEGs in these samples. Then, through GO, KEGG, and GSEA, regulation of endoplasmic reticulum stress-induced intrinsic apoptotic signaling pathway, FoxO signaling pathway, JAK-STAT signaling pathway, PI3K-Akt signaling pathway, TGF-beta signaling pathway, and ECM receptor interaction were involved in the regulatory mechanisms of the osteoarthritis pathogenesis. After that, the hub genes IL6 and DDIT3 were identified through PPI network construction and analysis. And it was found that IL6 was lowly expressed in the group with GlcN-treated MH7A cells, while DDIT3 was highly expressed.

CONCLUSION

The above results provide a basis for GlcN to participate in the treatment of osteoarthritis and a possibility for finding effective therapeutic targets.

IGF-1 Facilitates Cartilage Reconstruction by Regulating PI3K/AKT, MAPK, and NF-kB Signaling in Rabbit Osteoarthritis

Purpose

The pathogenesis of osteoarthritis (OA) is characterized by joint degeneration. The pro-inflammatory cytokine interleukin (IL)-1β plays a vital role in the pathogenesis of OA by stimulation of specific signaling pathways like NF-κB, PI3K/Akt, and MAPKs pathways. The catabolic role of growth factors in the OA may be inhibited cytokine-activated pathogen. The purpose of this study was to investigate the potential effects of insulin-like growth factor-1 (IGF-1) on IL-1β-induced apoptosis in rabbit chondrocytes in vitro and in an in vivo rabbit knee OA model.

Methods

In the present study, the OA developed in chondrocyte with the treatment of IL-1β and articular cartilage ruptures by removal of cartilage from the rabbit knee femoral condyle. After IGF-1 treatment, immunohistochemistry and qRT-PCR were identified OA expression with changes in MMPs (matrix metalloproteinases). The production of ROS (intracellular reactive oxygen species) in the OA was detected by flow cytometry. Further, the disease progression was microscopically investigated and pathophysiological changes were analyzed using histology. The NF-κB, PI3K/Akt and P38 (MAPK) specific pathways that are associated with disease progression were also checked using the Western blot technique.

Results

The expression of MMPs and various apoptotic markers are down-regulated following administration of IGF-1 in a dose-dependent fashion while significantly up-regulation of TIMP-1. The results showed that higher levels of ROS were observed upon treatment of chondrocytes and chondral OA with IL-1β. Collectively, our results indicated that IGF-1 protected NF-κB pathway by suppression of PI3K/Akt and MAPKs specific pathways. Furthermore, the macroscopic and pathological investigation showed that it has a chondroprotective effect by the formation of hyaline cartilage.

Conclusion

Our results indicate a protective effect of IGF-1 against OA pathogenesis by inhibition of NF-κB signaling via regulation of the MAPK and PI3K/Akt signaling pathways and prevention of apoptosis by suppression of ROS production.

Colchicine is not effective for reducing osteoarthritic hand pain compared to placebo: a randomised, placebo-controlled trial (COLAH)

BACKGROUND

Colchicine may offer relief in osteoarthritis. This has never been investigated for hand osteoarthritis.

OBJECTIVES

To investigate the effect of 1 mg daily colchicine vs placebo on hand pain and function over 12 weeks in older adults with hand osteoarthritis.

METHODS

Community-dwelling adults with diagnosed osteoarthritis of the hand aged 40-80 years were randomised to receive colchicine (0.5 mg twice daily) or matching placebo. Primary outcome measure was VAS hand pain score (0-100 mm). Secondary outcome measures included tender and swollen joint count, grip strength, C-reactive protein, and Michigan Hand Questionnaire total, function and pain scores. In an exploratory assessment, we compared synovial grade and power Doppler. All outcome measures were obtained at baseline and week 12. Stata v16 was used to perform constrained longitudinal data analysis models.

RESULTS

64 adults (54 females, 10 males) aged 48-79 years of age were enrolled. 59 participants completed the study (N = 28 colchicine, N = 31 placebo) (withdrawal rate 8%). Adverse reactions to the study medication occurred in nine patients. VAS score was not significantly different at baseline (61 ± 17 mm in the colchicine, 64 ± 17 mm in the placebo group). Between-group difference for VAS score at week 12 was 7.6 mm (95% CI -3.5-18.7, p-value 0.18). There were no significant differences between groups for any secondary outcomes at baseline or week 12.

CONCLUSIONS

1 mg colchicine daily for 12 weeks was not effective for reducing pain, tender and swollen joint count or increasing grip strength in symptomatic hand osteoarthritis. Our results do not support the use of colchicine in hand osteoarthritis.

Nutraceutical supplements in management of pain and disability in osteoarthritis: a systematic review and meta-analysis of randomized clinical trials

This study designed to evaluate the effect of nutraceutical supplementation on pain intensity and physical function in patients with knee/hip OA. The MEDLINE, Web of Science, Cochrane Library, Scopus, EMBASE, Google Scholar, Science direct, and ProQuest in addition to SID, Magiran, and Iranmedex were searched up to March 2020. Records (n = 465) were screened via the PICOS criteria: participants were patients with hip or knee OA; intervention was different nutritional supplements; comparator was any comparator; the outcome was pain intensity (Visual analogue scale [VAS]) and physical function (Western Ontario and McMaster Universities Arthritis [WOMAC] index); study type was randomized controlled trials. The random effects model was used to pool the calculated effect sizes. The standardized mean difference (SMD) of the outcome changes was considered as the effect size. The random effects model was used to combine the effect sizes. Heterogeneity between studies was assessed by Cochran's (Q) and I2 statistics. A total of 42 RCTs were involved in the meta-analysis. Nutritional supplementation were found to improve total WOMAC index (SMD = - 0.23, 95% CI - 0.37 to - 0.08), WOMAC pain (SMD = - 0.36, 95% CI - 0.62 to - 0.10) and WOMAC stiffness (SMD = - 0.47, 95% CI - 0.71 to - 0.23) subscales and VAS (SMD = - 0.79, 95% CI - 1.05 to - 0.05). Results of subgroup analysis according to the supplementation duration showed that the pooled effect size in studies with < 10 months, 10-20 months and > 20 months supplementation duration were 0.05, 0.27, and 0.36, respectively for WOMAC total score, 0.14, 0.55 and 0.05, respectively for WOAMC pain subscale, 0.59, 0.47 and 0.41, respectively for WOMAC stiffness subscale, 0.05, 0.57 and 0.53, respectively for WOMAC physical function subscale and 0.65, 0.99 and 0.12, respectively for VAS pain. The result suggested that nutraceutical supplementation of patients with knee/hip OA may lead to an improvement in pain intensity and physical function.

A comparative pilot study of oral diacerein and locally treated diacerein-loaded nanoparticles in a model of osteoarthritis

Diacerein (DIA) is a slow-acting drug for osteoarthritis (OA). Oral DIA administration, however, exerts side effects including diarrhea and urine discoloration. We fabricated DIA-loaded poly(d,l-lactide-co-glycolide) nanoparticles (DIA/PLGA NPs) that allow sustained release of DIA. In vitro, rat synoviocytes were used to investigate the cytotoxicity and anti-inflammatory effects of DIA-loaded NPs. In vivo, monosodium iodoacetate (MIA)-induced OA rats were divided into seven groups that included non-treated healthy control rats and rats injected with MIA alone or in combination with NPs, DIA(5%) solution, DIA(1%)/NPs, DIA(5%)/NPs, or oral DIA. The in vitro studies revealed that DIA/PLGA NPs dose-dependently suppressed mRNA levels of pro-inflammatory cytokines and enzymes, including interleukin-1 (IL-1), IL-6, tumor necrosis factor-α, matrix metalloproteinase-3 (MMP-3), MMP-13, cyclo-oxygenase-2, and a disintegrin and metalloproteinase with thrombospondin motifs-5 in synoviocytes. The in vivo studies demonstrated that intra-articular treatment of OA rat models with DIA-loaded PLGA NPs markedly decreased mRNA levels of these pro-inflammatory factors and increased those of anti-inflammatory cytokines (IL-4 and IL-10). Micro-computed tomography and histological evaluations indicated that intra-articular injection of DIA-loaded NPs was effective in protecting against cartilage degradation. Administration of DIA/PLGA NPs via intra-articular injection is promising for inhibiting inflammation and protecting against cartilage degradation in OA.

Tankyrase inhibition preserves osteoarthritic cartilage by coordinating cartilage matrix anabolism via effects on SOX9 PARylation

Osteoarthritis (OA) is a prevalent degenerative disease, which involves progressive and irreversible destruction of cartilage matrix. Despite efforts to reconstruct cartilage matrix in osteoarthritic joints, it has been a difficult task as adult cartilage exhibits marginal repair capacity. Here we report the identification of tankyrase as a regulator of the cartilage anabolism axis based on systems-level factor analysis of mouse reference populations. Tankyrase inhibition drives the expression of a cartilage-signature matrisome and elicits a transcriptomic pattern that is inversely correlated with OA progression. Furthermore, tankyrase inhibitors ameliorate surgically induced OA in mice, and stem cell transplantation coupled with tankyrase knockdown results in superior regeneration of cartilage lesions. Mechanistically, the pro-regenerative features of tankyrase inhibition are mainly triggered by uncoupling SOX9 from a poly(ADP-ribosyl)ation (PARylation)-dependent protein degradation pathway. Our findings provide insights into the development of future OA therapies aimed at reconstruction of articular cartilage.

Osteoarthritis results from the progressive destruction of cartilage matrix. Here, Kim et al. identify tankyrase as a regulator of cartilage matrix anabolism, and find that tankyrase inhibition, by preventing SOX9 PARylation, protects from cartilage destruction in a mouse model of osteoarthritis.

The effect of mobilization with movement on pain and function in patients with knee osteoarthritis: a randomized double-blind controlled trial

BACKGROUND

Few studies have investigated the effects of mobilization with movement (MWM) in patients with knee osteoarthritis (OA) compared to other procedures. Sham procedures are generally more appropriate control than using no or usual treatments. Moreover, studies investigating the widespread hypoalgesic effects of MWM in patients with knee OA are lacking. The aim was to investigate the effect of MWM on function and pain in patients with knee OA compared to sham MWM.

METHODS

This is a randomized double-blind (patients and assessor) controlled trial. Forty adult patients with knee OA of grade II and above were recruited to receive either MWM treatment or sham MWM for the knee. The outcome measures included the following: a visual analogue scale (VAS) for pain, the pressure pain threshold (PPT) test, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index, the timed up and go (TUG) test, knee strength and knee range of motion (ROM). The measurements were taken at baseline, immediately after intervention and 2 days later.

RESULTS

Compared with sham MWM, MWM resulted in greater immediate improvement in pain [mean difference (95% CI): - 2.2 (- 2.8, - 1.6)], PPT at both the knee [176 (97, 254)] and shoulder [212 (136, 288)], TUG time [- 1.6 (- 2.1, - 1.1)], knee flexor strength [2.0 (1.3, 2.7)] and extensor strength [5.7 (4.1, 7.2)] and knee flexion ROM [12.8 (9.6, 15.9)] (all, p < 0.001) but not knee extension ROM [- 0.8 (- 1.6, 0.1)] (p = 0.067). After 2 days of intervention, patients who received MWM also demonstrated a greater improvement in pain [- 1.0 (- 1.8, - 0.1)], PPT at the shoulder [107 (40, 175)], TUG time [- 0.9 (- 1.4, - 0.4)], knee flexor strength [0.9 (0.2, 1.7)] and extensor strength [2.9 (2.1, 3.9)] and knee flexion ROM [8.3 (4.7, 11.9)] (all, p ≤ 0.026). However, WOMAC scores and knee extension ROM showed no evidence of change at any stage after intervention (p ≥ 0.067).

CONCLUSIONS

MWM provided superior benefits over sham MWM in terms of local and widespread pain, physical function (walking), knee flexion and extension muscle strength and knee flexion ROM for at least 2 days in patients with knee OA.

TRIAL REGISTRATION

ClinicalTrials.gov ( NCT02865252 ), registered on August 12, 2016.

The pathogenic role of connective tissue growth factor in osteoarthritis

Osteoarthritis (OA) is the most common form of arthritis, and connective tissue growth factor (CTGF) is found to be up-regulated in adjacent areas of cartilage surface damage. CTGF is present in osteophytes of late stage OA. In the present study, we have reviewed association of CTGF in the development and progression of OA and the potential effects of CTGF as a therapeutic agent for the treatment of OA. We have reviewed the recent articles on CTGF and OA in databases like PubMed, google scholar, and SCOPUS and collected the information for the articles. CTGF is usually up-regulated in synovial fluid of OA that stimulates the production of inflammatory cytokines. CTGF also activates nuclear factor-κB, increases the production of chemokines and cytokines, and up-regulates matrix metalloproteinases-3 (MMP-3) that in turn leads to the reduction in proteoglycan contents in joint cartilage. Consequently, cartilage homeostasis is imbalanced that might contribute to the pathogenesis of OA by developing synovial inflammation and cartilage degradation. CTGF might serve as a useful biomarker for the prognosis and treatment of OA, and recent studies have taken attempt to use CTGF as therapeutic target of OA. However, more investigations with clinical trials are necessary to validate the possibility of use of CTGF as a biomarker in OA diagnosis and therapeutic target for OA treatment.

Effects of anti-osteoporosis medications on total hip arthroplasty risks in osteoporotic patients with hip osteoarthritis in Taiwan: a nationwide cohort study

This nationwide cohort study examined the potential disease-modifying effect of anti-osteoporosis medication on hip osteoarthritis. The results revealed that the usage of anti-osteoporosis medication is not associated with decreased risk in undergoing total hip arthroplasty in patient with hip osteoarthritis.

PURPOSE

This study aimed to assess the association between use of anti-osteoporosis medications (AOMs) and the risk of undergoing total hip arthroplasty (THA) in patients with hip osteoarthritis (OA).

METHODS

Using the 2008-2013 National Health Insurance Research Database, we identified patients who were first diagnosed as having hip OA. All identified patients were followed until THA, death of any cause, or December 31, 2013, whichever occurred first. All AOM exposures were divided into three categories: bisphosphonates use, non-bisphosphonates use, and no use of AOMs and assessed in a time-varying manners. The primary outcome was THA. The secondary outcome was the differences in the longitudinal utilization of NSAIDs between AOM users and non-users. Time-dependent Cox proportional hazards models were used to investigate the effect of AOM use on the risk of THA.

RESULTS

We identified 35,870 patients who were first diagnosed as having hip OA and had no history of AOM use between 2009 and 2012. Among them, 3162 and 1667 patients had their first prescription of bisphosphonates and other non-bisphosphonates AOMs during the follow-up period. Mean age of bisphosphonates users, non-bisphosphonates users, and non-users was 75.62, 76.84, and 67.39 years, respectively. Bisphosphonates or non-bisphosphonates users did not show significant change when compared to non-users in terms of risk of undergoing THA [adjusted hazard ratio (aHR) 0.972, 95% confidence interval (CI) 0.743-1.273; aHR 0.926, 95% CI 0.672-1.277].

CONCLUSION

Our results showed that the use of AOMs is not associated with decreased risk of THA in patients with hip OA.

Active agents, biomaterials, and technologies to improve biolubrication and strengthen soft tissues

Normal functioning of articulating tissues is required for many physiological processes occurring across length scales from the molecular to whole organism. Lubricating biopolymers are present natively on tissue surfaces at various sites of biological articulation, including eyelid, mouth, and synovial joints. The range of operating conditions at these disparate interfaces yields a variety of tribological mechanisms through which compressive and shear forces are dissipated to protect tissues from material wear and fatigue. This review focuses on recent advances in active agents and biomaterials for therapeutic augmentation of friction, lubrication, and wear in disease and injured states. Various small-molecule, biological, and gene delivery therapies are described, as are tribosupplementation with naturally-occurring and synthetic biolubricants and polymer reinforcements. While reintroduction of a diseased tissue's native lubricant received significant attention in the past, recent discoveries and pre-clinical research are capitalizing on concurrent advances in the molecular sciences and bioengineering fields, with an understanding of the underlying tissue structure and physiology, to afford a desired, and potentially patient-specific, tissue mechanical response for restoration of normal function. Small and large molecule drugs targeting recently elucidated pathways as well as synthetic and hybrid natural/synthetic biomaterials for restoring a desired tissue mechanical response are being investigated for treatment of, for example, keratoconjunctivitis sicca, xeroderma, and osteoarthritis.

Do Neuroendocrine Peptides and Their Receptors Qualify as Novel Therapeutic Targets in Osteoarthritis?

Joint tissues like synovium, articular cartilage, meniscus and subchondral bone, are targets for neuropeptides. Resident cells of these tissues express receptors for various neuroendocrine-derived peptides including proopiomelanocortin (POMC)-derived peptides, i.e., α-melanocyte-stimulating hormone (α-MSH), adrenocorticotropin (ACTH) and β-endorphin (β-ED), and sympathetic neuropeptides like vasoactive intestinal peptide (VIP) and neuropeptide y (NPY). Melanocortins attained particular attention due to their immunomodulatory and anti-inflammatory effects in several tissues and organs. In particular, α-MSH, ACTH and specific melanocortin-receptor (MCR) agonists appear to have promising anti-inflammatory actions demonstrated in animal models of experimentally induced arthritis and osteoarthritis (OA). Sympathetic neuropeptides have obtained increasing attention as they have crucial trophic effects that are critical for joint tissue and bone homeostasis. VIP and NPY are implicated in direct and indirect activation of several anabolic signaling pathways in bone and synovial cells. Additionally, pituitary adenylate cyclase-activating polypeptide (PACAP) proved to be chondroprotective and, thus, might be a novel target in OA. Taken together, it appears more and more likely that the anabolic effects of these neuroendocrine peptides or their respective receptor agonists/antagonists may be exploited for the treatment of patients with inflammatory and degenerative joint diseases in the future.

Chitosan in viscosupplementation: in vivo effect on rabbit subchondral bone

Background

To investigate the effect of intra-articular injection of Chitosan (Cs) added to hyaluronic acid (HA) on subchondral bone during osteoarthritis (OA), microarchitectural parameters and mineral density were measured in a rabbit model of early OA. A novel hybrid hydrogel adding reacetylated Cs of fungal origin to HA was compared to high molecular weight HA commercial formulation.

Method

Eighteen rabbits underwent unilateral anterior cruciate ligament transection (ACLT) and were divided into three groups (Saline-group, HA-group and Hybrid-group) depending on the intra-articular injection compound. Eight contralateral knees were used as non-operated controls (Contralateral-group). Micro-computed tomography was performed six weeks post-ACLT to study subchondral bone microarchitectural parameters and mineral density at an early stage of OA development.

Results

Cartilage thickness mean value was reduced only in Saline-group compared to Contralateral-group. When the Hybrid-group was compared to Saline-group, subchondral bone microarchitectural parameters (trabecular thickness and trabecular bone volume fraction) were significantly changed; subchondral bone plate and trabecular bone mineral densities (bone mineral density and tissue mineral density) were reduced. When the Hybrid-group was compared to HA-group, subchondral bone microarchitectural parameters (subchondral plate thickness and trabecular thickness) and trabecular bone mineral densities (bone mineral density and tissue mineral density) were significantly decreased.

Conclusion

Conclusion: Compared to HA alone, the novel hybrid hydrogel, constituted of Cs added to HA, enhanced microarchitectural parameters and mineral density changes, leading to subchondral bone loss in a rabbit model of early experimental OA.

Synthesis, Biological Evaluation, and Docking Studies of a Novel Sulfonamido-Based Gallate as Pro-Chondrogenic Agent for the Treatment of Cartilage

Gallic acid (GA) and its derivatives are anti-inflammatory agents and are reported to have potent effects on Osteoarthritis (OA) treatment. Nonetheless, it is generally accepted that the therapeutic effect and biocompatibility of GA is much weaker than its esters due to the high hydrophilicity. The therapeutic effect of GA on OA could be improved if certain structural modifications were made to increase its hydrophobicity. In this study, a novel sulfonamido-based gallate was synthesized by bonding sulfonamide with GA, and its biological evaluations on OA were investigated. Results show that 5-[4-(Pyrimidin-2-ylsulfamoylphenyl)]-carbamoyl-benzene-1,2,3-triyl triacetate (HAMDC) was able to reverse the effects induced by Interleukin-1 (IL-1) stimulation, and it also had a great effect on chondro-protection via promoting cell proliferation and maintaining the phenotype of articular chondrocytes, as well as enhancing synthesis of cartilage specific markers such as aggrecan, collagen II and Sox9. Furthermore, a docking study showed that HAMDC fits into the core of the active site of a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), which provides an explanation for its activity and selectivity.

Discovery of Potent and Selective Inhibitors for ADAMTS-4 through DNA-Encoded Library Technology (ELT)

The aggrecan degrading metalloprotease ADAMTS-4 has been identified as a novel therapeutic target for osteoarthritis. Here, we use DNA-encoded Library Technology (ELT) to identify novel ADAMTS-4 inhibitors from a DNA-encoded triazine library by affinity selection. Structure-activity relationship studies based on the selection information led to the identification of potent and highly selective inhibitors. For example, 4-(((4-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)-6-(((4-methylpiperazin-1-yl)methyl)amino)-1,3,5-triazin-2-yl)amino)methyl)-N-ethyl-N-(m-tolyl)benzamide has IC50 of 10 nM against ADAMTS-4, with >1000-fold selectivity over ADAMT-5, MMP-13, TACE, and ADAMTS-13. These inhibitors have no obvious zinc ligand functionality.

Chondroitin for osteoarthritis

BACKGROUND

Osteoarthritis, a common joint disorder, is one of the leading causes of disability. Chondroitin has emerged as a new treatment. Previous meta-analyses have shown contradictory results on the efficacy of chondroitin. This, in addition to the publication of more trials, necessitates a systematic review.

OBJECTIVES

To evaluate the benefit and harm of oral chondroitin for treating osteoarthritis compared with placebo or a comparator oral medication including, but not limited to, nonsteroidal anti-inflammatory drugs (NSAIDs), analgesics, opioids, and glucosamine or other "herbal" medications.

SEARCH METHODS

We searched seven databases up to November 2013, including the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, CINAHL, EMBASE, Science Citation Index (Web of Science) and Current Controlled Trials. We searched the US Food and Drug Administration (FDA) and European Medicines Agency (EMEA) websites for adverse effects. Trial registers were not searched.

SELECTION CRITERIA

All randomized or quasi-randomized clinical trials lasting longer than two weeks, studying adults with osteoarthritis in any joint, and comparing chondroitin with placebo, an active control such as NSAIDs, or other "herbal" supplements such as glucosamine.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed all title assessments, data extractions, and risk of bias assessments.

MAIN RESULTS

Forty-three randomized controlled trials including 4,962 participants treated with chondroitin and 4,148 participants given placebo or another control were included. The majority of trials were in knee OA, with few in hip and hand OA. Trial duration varied from 1 month to 3 years. Participants treated with chondroitin achieved statistically significantly and clinically meaningful better pain scores (0-100) in studies less than 6 months than those given placebo with an absolute risk difference of 10% lower (95% confidence interval (CI), 15% to 6% lower; number needed to treat (NNT) = 5 (95% CI, 3 to 8; n = 8 trials) (level of evidence, low; risk of bias, high); but there was high heterogeneity between the trials (T(2) = 0.07; I(2) = 70%, which was not easily explained by differences in risk of bias or study sample size). In studies longer than 6 months, the absolute risk difference for pain was 9% lower (95% CI 18% lower to 0%); n = 6 trials; T(2) = 0.18; I(2) = 83% ), again with low level of evidence.For the Western Ontario and McMaster Universities Osteoarthritis Index Minimal Clinically Important Improvement (WOMAC MCII Pain subscale) outcome, a reduction in knee pain by 20% was achieved by 53/100 in the chondroitin group versus 47/100 in the placebo group, an absolute risk difference of 6% (95% CI 1% to 11%), (RR 1.12, 95% CI 1.01 to 1.24; T(2) = 0.00; I(2) = 0%) (n = 2 trials, 1253 participants; level of evidence, high; risk of bias, low).Differences in Lequesne's index (composite of pain,function and disability) statistically significantly favoured chondroitin as compared with placebo in studies under six months, with an absolute risk difference of 8% lower (95% CI 12% to 5% lower; T(2)= 0.78; n = 7 trials) (level of evidence, moderate; risk of bias, unclear), also clinically meaningful. Loss of minimum joint space width in the chondroitin group was statistically significantly less than in the placebo group, with a relative risk difference of 4.7% less (95% CI 1.6% to 7.8% less; n = 2 trials) (level of evidence, high; risk of bias, low). Chondroitin was associated with statistically significantly lower odds of serious adverse events compared with placebo with Peto odds ratio of 0.40 (95% CI 0.19 to 0.82; n = 6 trials) (level of evidence, moderate). Chondroitin did not result in statistically significant numbers of adverse events or withdrawals due to adverse events compared with placebo or another drug. Adverse events were reported in a limited fashion, with some studies providing data and others not.Comparisons of chondroitin taken alone or in combination with glucosamine or another supplement showed a statistically significant reduction in pain (0-100) when compared with placebo or an active control, with an absolute risk difference of 10% lower (95% CI 14% to 5% lower); NNT = 4 (95% CI 3 to 6); T(2) = 0.33; I(2) = 91%; n = 17 trials) (level of evidence, low). For physical function, chondroitin in combination with glucosamine or another supplement showed no statistically significant difference from placebo or an active control, with an absolute risk difference of 1% lower (95% CI 6% lower to 3% higher with T(2) = 0.04; n = 5 trials) (level of evidence, moderate). Differences in Lequesne's index statistically significantly favoured chondroitin as compared with placebo, with an absolute risk difference of 8% lower (95% CI, 12% to 4% lower; T(2) = 0.12; n = 10 trials) (level of evidence, moderate). Chondroitin in combination with glucosamine did not result in statistically significant differences in the numbers of adverse events, withdrawals due to adverse events, or in the numbers of serious adverse events compared with placebo or with an active control.The beneficial effects of chondroitin in pain and Lequesne's index persisted when evidence was limited to studies with adequate blinding or studies that used appropriate intention to treat (ITT) analyses. These beneficial effects were uncertain when we limited data to studies with appropriate allocation concealment or a large study sample (> 200) or to studies without pharmaceutical funding.

AUTHORS' CONCLUSIONS

A review of randomized trials of mostly low quality reveals that chondroitin (alone or in combination with glucosamine) was better than placebo in improving pain in participants with osteoarthritis in short-term studies. The benefit was small to moderate with an 8 point greater improvement in pain (range 0 to 100) and a 2 point greater improvement in Lequesne's index (range 0 to 24), both seeming clinically meaningful. These differences persisted in some sensitivity analyses and not others. Chondroitin had a lower risk of serious adverse events compared with control. More high-quality studies are needed to explore the role of chondroitin in the treatment of osteoarthritis. The combination of some efficacy and low risk associated with chondroitin may explain its popularity among patients as an over-the-counter supplement.

Posttraumatic knee osteoarthritis following anterior cruciate ligament injury: Potential biochemical mediators of degenerative alteration and specific biochemical markers

As a common injury, anterior cruciate ligament (ACL) injury is unable to heal itself naturally, which possibly increases knee instability, accelerates the risk of joint degeneration and leads to knee osteoarthritis (OA) in the ACL-injured knee. Thus, ACL reconstruction using an autograft or allograft tendon is proposed to maintain the biomechanical stability of the knee joint. However, previous studies demonstrate that surgical management of ACL reconstruction failed to abrogate the development of OA completely, indicating that biochemical disturbance is responsible for the osteoarthritic changes observed following ACL injury. Inflammatory mediators are elevated subsequent to ACL injury or rupture, inducing matrix metalloproteinase production, proteoglycan degradation, collagen destruction, chondrocyte necrosis and lubricin loss. These potential biochemical mediators may aid in the development of effective biological management to reduce the onset of future posttraumatic OA. Furthermore, during the degenerative process of cartilage, there are a number of cartilage-specific biomarkers, which play a critical step in the loss of structural and functional integrity of cartilage. The present review illustrates several specific biomarkers in the ACL-injured knee joint, which may provide effective diagnostic and prognostic tools for investigating cartilage degenerative progression and future posttraumatic OA of ACL-injured patients.

Topical Ginger Treatment With a Compress or Patch for Osteoarthritis Symptoms

AIM

This article is a report of a study evaluating changes in health status before and after topical ginger treatment for adults with moderate to severe osteoarthritis.

METHOD

In 2011, 20 adults with chronic osteoarthritis were randomly assigned to one of two groups for 7 consecutive days of topical ginger treatment by trained nurses: Group 1 received a manually prepared ginger compress and Group 2 a standardized ginger patch. Participants had the option to continue self-treatment using the ginger patch for a further 24 weeks. A brief arthritis health questionnaire was completed weekly for 3 weeks and 4 weekly for 24 weeks.

RESULTS

The mean scores for Group 1 and Group 2 show a notable decline following 1-week topical ginger treatment; scores in pain, fatigue, global effect, and functional status reduced by 48%, 49%, 40%, and 31%, respectively, whereas health satisfaction improved from 80% dissatisfied to 70% satisfied. Scores for all participants in all five domains progressively reduced over the following 24 weeks of self-treatment.

CONCLUSION

Topical ginger treatment has the potential to relieve symptoms, improve the overall health, and increase independence of people with chronic osteoarthritis.

A three-dimensionally engineered biomimetic cartilaginous tissue model for osteoarthritic drug evaluation

Osteoarthritis (OA) is primarily characterized by focal cartilage destruction and synovitis. Presently, the pathogenesis of OA remains unclear, and an effective treatment methodology is an unmet need. To this end, a plethora of animal models and monolayer models have been developed, but they are faced with the limitation of high cost and inability to recapitulate a pure hyaline cartilaginous phenotype, which is important in studying the efficacy of therapeutic agents. We have previously developed a living hyaline cartilage graft (LhCG) that accurately presented a pure hyaline cartilage phenotype. Here, through the coculture of lipopolysaccharide (LPS)-activated macrophages with LhCG, we hypothesized that an accurate OA disease model may be developed. Subsequently, this model was evaluated for its accuracy for in vitro drug testing. Results indicated that chondrocyte proliferation and apoptosis were increased in the disease model. Additionally, extracellular matrix (ECM) synthesis increased as indicated by the increased anabolic gene expression levels, such as collagen type II and aggrecan. Up-regulation of matrix metalloproteinase-1 (MMP-1) and MMP-3 genes suggested increased degradative activity, while chondrocytic hypertrophic differentiation was observed. Furthermore, extensive degradation of collagen type II and glycosaminoglycans (GAGs) were also observed. The results of celecoxib treatment on our model showed inhibition of nitric oxide (NO) and prostaglandin E2 (PGE2) production, as well as down-regulation of MMP-1 and MMP-3 expression. Taken together, the results suggested that this coculture model was able to sufficiently mimic the native, diseased OA cartilage, while drug testing results confirmed its suitability as an in vitro model for predicting native cartilage response to drug treatment.

Osteoarthritis: genes, nature-nurture interaction and the role of leptin

Osteoarthritis (OA) is a common disease affecting patients at different ages regardless of gender or ethnicity. As with many chronic diseases, OA is thought to have a multifactorial aetiology, which is not fully understood. Whereas the pathophysiological process of OA can be analysed at a cellular and molecular level, the interaction between genes and lifestyle remains an important factor in the development of this disease. The expanding awareness of different genes that may play a role in OA, together with many chemical mediators thought to be associated with the progression of the disease, will help in better management of this condition. Some of the chemical mediators recently implicated in this condition are the adipokines (leptin, adiponectin and resistin). Few but consistent studies suggest that leptin in association with obesity could be an important factor in OA aetiology. Hence, this could establish a strong and direct molecular link between patient life style (nurture) and the pathological process of OA (nature). However, neither a clear mechanism nor a direct clinical association linking leptin to OA has yet been established. In this article, we explore some of the genetic and environmental factors in OA aetiology. We discuss leptin in obesity and assess its possible association with OA aetiology. This should emphasise the important role of health professionals in treating obesity in order to control OA symptoms and possibly progression.

Hypoxia promotes the production and inhibits the destruction of human articular cartilage

OBJECTIVE

To determine the effects of hypoxia on both anabolic and catabolic pathways of metabolism in human articular cartilage and to elucidate the roles played by hypoxia-inducible factors (HIFs) in these responses.

METHODS

Normal human articular cartilage from a range of donors was obtained at the time of above-the-knee amputations due to sarcomas not involving the joint space. Fresh cartilage tissue explants and isolated cells were subjected to hypoxia and treatment with interleukin-1α. Cell transfections were performed on isolated human chondrocytes.

RESULTS

Using chromatin immunoprecipitation, we found that hypoxia induced cartilage production in human tissue explants through direct binding of HIF-2α to a specific site in the master-regulator gene SOX9. Importantly, hypoxia also suppressed spontaneous and induced destruction of human cartilage in explant culture. We found that anticatabolic responses were predominantly mediated by HIF-1α. Manipulation of the hypoxia-sensing pathway through depletion of HIF-targeting prolyl hydroxylase-containing protein 2 (PHD-2) further enhanced cartilage responses as compared to hypoxia alone. Hypoxic regulation of tissue-specific metabolism similar to that in human cartilage was observed in pig, but not mouse, cartilage.

CONCLUSION

We found that resident chondrocytes in human cartilage are exquisitely adapted to hypoxia and use it to regulate tissue-specific metabolism. Our data revealed that while fundamental regulators, such as SOX9, are key molecules both in mice and humans, the way in which they are controlled can differ. This is all the more important since it is upstream regulators such as this that need to be directly targeted for therapeutic benefit. HIF-specific hydroxylase PHD-2 may represent a relevant target for cartilage repair.

Potential directions for drug development for osteoarthritis

BACKGROUND

Osteoarthritis (OA) is a frustrating disease for both patient and physician because neither cause nor cure is known and there are currently no disease-modifying drugs.

OBJECTIVE

To review current therapeutic approaches as well as new findings regarding OA pathoetiology that could form the basis of future direction for the development of drugs to prevent or slow down disease progression.

METHODS

After reviewing disease progression in human OA, as demonstrated by histological analyses, the reasons for cartilage erosion are explored and possible therapeutic approaches are highlighted.

RESULTS/CONCLUSIONS

OA may be an epigenetic disease. This new concept can explain many aspects of the disease and provide reasons why therapeutic approaches until now have met with little success.

Generation of human induced pluripotent stem cells from osteoarthritis patient-derived synovial cells

OBJECTIVE

This study was undertaken to generate and characterize human induced pluripotent stem cells (PSCs) from patients with osteoarthritis (OA) and to examine whether these cells can be developed into disease-relevant cell types for use in disease modeling and drug discovery.

METHODS

Human synovial cells isolated from two 71-year-old women with advanced OA were characterized and reprogrammed into induced PSCs by ectopic expression of 4 transcription factors (Oct-4, SOX2, Klf4, and c-Myc). The pluripotency status of each induced PSC line was validated by comparison with human embryonic stem cells (ESCs).

RESULTS

We found that OA patient-derived human synovial cells had human mesenchymal stem cell (MSC)-like characteristics, as indicated by the expression of specific markers, including CD14-, CD19-, CD34-, CD45-, CD44+, CD51+, CD90+, CD105+, and CD147+. Microarray analysis of human MSCs and human synovial cells further determined their unique and overlapping gene expression patterns. The pluripotency of established human induced PSCs was confirmed by their human ESC-like morphology, expression of pluripotency markers, gene expression profiles, epigenetic status, normal karyotype, and in vitro and in vivo differentiation potential. The potential of human induced PSCs to differentiate into distinct mesenchymal cell lineages, such as osteoblasts, adipocytes, and chondrocytes, was further confirmed by positive expression of markers for respective cell types and positive staining with alizarin red S (osteoblasts), oil red O (adipocytes), or Alcian blue (chondrocytes). Functional chondrocyte differentiation of induced PSCs in pellet culture and 3-dimensional polycaprolactone scaffold culture was assessed by chondrocyte self-assembly and histology.

CONCLUSION

Our findings indicate that patient-derived synovial cells are an attractive source of MSCs as well as induced PSCs and have the potential to advance cartilage tissue engineering and cell-based models of cartilage defects.

Arylsulfonamide inhibitors of aggrecanases as potential therapeutic agents for osteoarthritis: synthesis and biological evaluation

Aggrecanases, in particular aggrecanase-2 (ADAMTS-5), are considered the principal proteases responsible for aggrecan degradation in osteoarthritis. For this reason, considerable effort has been put on the discovery and development of aggrecanase inhibitors able to slow down or halt the progression of osteoarthritis. We report herein the synthesis and biological evaluation of a series of arylsulfonamido-based hydroxamates as aggrecanase inhibitors. Compound 18 was found to have a nanomolar activity for ADAMTS-5, ADAMTS-4 and MMP-13 and high selectivity over MMP-1 and MMP-14. Furthermore, this compound proved to be effective in blocking ex vivo cartilage degradation without having effect on cell cytotoxicity.

The design and synthesis of novel N-hydroxyformamide inhibitors of ADAM-TS4 for the treatment of osteoarthritis

Two series of N-hydroxyformamide inhibitors of ADAM-TS4 were identified from screening compounds previously synthesised as inhibitors of matrix metalloproteinase-13 (collagenase-3). Understanding of the binding mode of this class of compound using ADAM-TS1 as a structural surrogate has led to the discovery of potent and very selective inhibitors with favourable DMPK properties. Synthesis, structure-activity relationships, and strategies to improve selectivity and lower in vivo metabolic clearance are described.

Treatment of knee osteoarthritis with Orthokine-derived autologous conditioned serum

Osteoarthritis (OA) is the most prevalent arthritis in the world with increasing numbers of people expected to acquire the disease as the population ages. Therapies commonly used to manage the disease have limited efficacy and some carry significant risks. Current data suggest that the anti-inflammatory cytokine IL-1 receptor antagonist (IL-1Ra) can alter the inflammatory response and cartilage erosion present in OA. Intra-articular gene expression of IL-1Ra has shown promising results in animal models to provide symptomatic improvement and minimize osteoarthritic changes. Orthogen AG (Dusseldorf, Germany) has developed a method to produce an autologous conditioned serum (ACS) rich in IL-1Ra marketed as Orthokine. Study participants treated with ACS have improved pain and function; however, these results are preliminary and need confirmation. If ongoing trials prove that ACS can retard cartilage degeneration and reduce inflammation, the management of OA would be dramatically altered, perhaps providing a mechanism to prevent the disease or at least its progression.

A combined phase I and II open label study on the effects of a seaweed extract nutrient complex on osteoarthritis

Background:

Isolated fucoidans from brown marine algae have been shown to have a range of anti-inflammatory effects.

Purpose:

This present study tested a Maritech^® extract formulation, containing a blend of extracts from three different species of brown algae, plus nutrients in an open label combined phase I and II pilot scale study to determine both acute safety and efficacy in osteoarthritis of the knee.

Patients and methods:

Participants (n = 12, five females [mean age, 62 ± 11.06 years] and seven males [mean age, 57.14 ± 9.20 years]) with a confirmed diagnosis of osteoarthritis of the knee were randomized to either 100 mg (n = 5) or 1000 mg (n = 7) of a Maritech^® extract formulation per day. The formulation contained Maritech^® seaweed extract containing Fucus vesiculosis (85% w/w), Macrocystis pyrifera (10% w/w) and Laminaria japonica (5% w/w) plus vitamin B6, zinc and manganese. Primary outcome was the average comprehensive arthritis test (COAT) score which is comprised of four sub-scales: pain, stiffness, difficulty with physical activity and overall symptom severity measured weekly. Safety measures included full blood count, serum lipids, liver function tests, urea, creatinine and electrolytes determined at baseline and week 12. All adverse events were recorded.

Results:

Eleven participants completed 12 weeks and one completed 10 weeks of the study. Using a multilevel linear model, the average COAT score was reduced by 18% for the 100 mg treatment and 52% for the 1000 mg dose at the end of the study. There was a clear dose response effect seen between the two treatments (P ≤ 0.0005) on the average COAT score and each of the four COAT subscales (pain, stiffness, difficulty with physical activity and overall symptom severity) (P ≤ 0.05). The preparation was well tolerated and the few adverse events were unlikely to be related to the study medication. There were no changes in blood parameters measured over the course of the study with the exception of an increase in serum albumin which was not clinically significant.

Conclusion:

The seaweed extract nutrient complex when taken orally over twelve weeks decreased the symptoms of osteoarthritis in a dose-dependent manner. It was demonstrated to be safe to use over the study period at the doses tested. The efficacy of the preparation now needs to be demonstrated in a phase III randomized controlled trial (RCT).

Australian and New Zealand Clinical Trials Register:

ACTRN12607000229471.

Importance of pharmaceutical composition and evidence from clinical trials and pharmacological studies in determining effectiveness of chondroitin sulphate and other glycosaminoglycans: a critique

Objectives

Chondroitin sulphate (CS) has attracted much interest over the past two decades or so as a biological agent for use in the relief of pain and joint symptoms in osteoarthritis. Earlier clinical investigations produced variable, if encouraging results. This variability was partly due to limitations on the study designs and the lack of availability of standardized CS. Recently, high quality and fully standardized CS (Condrosulf) has become available and its effects have been studied in large-scale osteoarthritis trials, which are discussed here.

Key findings

There is now evidence for symptom - and structure-modifying (radio-logically-observed) effects. These studies show that CS (a) has slow onset of response and that relief of pain may not be like that of the direct analgesic actions of non-steroidal anti-inflammatory drugs (NSAIDs), (b) there are indications of reduced need for intake of analgesics (e.g. NSAIDs) in patients taking CS, and (c) quality of life and cost-benefits may be associated with use of CS. Safety evaluations show that the incidence of adverse reactions is low. Pharmacokinetic studies indicate that although oral absorption is relatively fast CS has moderate oral bioavailability (15–24%) and that depolymerised and degraded CS that is evident after absorption, together with CS itself, may take some time to accumulate in target joints. The pharmacodynamic actions of CS indicate that it has anti-inflammatory effects that include multiple actions involving reduction of catabolic reactions and enhanced anabolic (proteoglycan) synthetic reactions in cartilage and may block osteoclast activation in bone. Further studies are required to (a) establish the effects of depolymerised and degraded CS on degradation of cartilage and bone in vitro, and (b) MRI and other investigations of the effects in osteoarthritis of long-term CS treatment.

Summary

The findings from this review show there may be potential value of CS in reducing the dependence on intake of NSAIDs and analgesics in patients with osteoarthritis, while at the same time having favourable safety.

Chondroitin sulfate for the treatment of hip and knee osteoarthritis: current status and future trends

AIMS

Osteoarthritis (OA) is a common joint disorder and a major socio-economic burden. Chondroitin sulfate (CS), which has chondroprotective properties, is a promising candidate for the therapeutic treatment of OA. Here, we summarize current knowledge as well as future trends of CS for the treatment of hip and knee OA.

MAIN METHODS

We retrospectively reviewed pharmacokinetics, pharmacodynamics, clinical efficacy, safety and tolerability of CS for the treatment of OA.

KEY FINDINGS

The safety and tolerability of CS are confirmed. CS is effective, at least in part, for the treatment of OA, and its therapeutic benefits occur through three main mechanisms: 1) stimulation of extracellular matrix production by chondrocytes; 2) suppression of inflammatory mediators; and 3) inhibition of cartilage degeneration.

SIGNIFICANCE

CS is a safe and tolerable therapeutic agent for the management of OA. Its effects include benefits that are not achieved by current medicines and include chondroprotection and the prevention of joint space narrowing. Such positive effects of CS represent a breakthrough in the treatment of hip and knee OA.

Optimal 99mTc radiolabeling and uptake of glucosamine sulfate by cartilage. A potential tracer for scintigraphic detection of osteoarthritis

Glucosamine sulfate (GS) is used in treatment of human osteoarthritis, but no data for(99m)TcGS scintigraphy are available. Radiolabeling of GS was performed using the (99m)TcO(4)(-)/tin method. We applied two procedures for separation of free (99m)Tc using PD10 and G10 columns. In each eluted fraction, GS content was estimated by the Elson/Morgan method. For optimal radiolabeling, we varied the amount of GS, tin, (99m)Tc activity, and pH. For uptake age matched human rib cartilage (males, 78 and 63 years old) and 5-10 μCi/well of (99m)TcGS were used. Uptake was monitored up to 72 h. Also, washout of the tracer 3 h and 24 h after uptake was investigated. At pH 2, using PD10 column, the uptake of (99m)TcGS amounted to 100.8 ± 2.9%, n = 6 at saturation time of 72 h. Uptake was age-dependent; at pH 5, it amounted to 99.8% as compared to 66.1% at 78 vs 63 years old. When the amount of tin was varied at pH 2, the tracer uptake amounted to 21.37% (1 mg) vs 45.99% (2.5 mg) at saturation. At pH 7, the amount of needed tin was much lower and amounted to 42.50 ± 2.50% using 0.1 mg vs 25.11 ± 1.90% using 0.05 mg. Although the uptake at pH 7 (0.1 mg tin) is comparable with that at pH 2 (2.5 mg tin), the washout of the tracer amounted only to 4.10 ± 1.25% and 2.05 ± 0.65% after 3 h and 24 h, respectively. During degeneration of cartilage, incorporation of (99m)TcGS is high and could therefore be a promising tracer not only to target osteoarthritis but also to monitor the effects of therapy.

Comparison of the effectiveness and tolerability of lidocaine patch 5% versus celecoxib for osteoarthritis-related knee pain: post hoc analysis of a 12 week, prospective, randomized, active-controlled, open-label, parallel-group trial in adults

BACKGROUND

Cyclooxygenase-2 (COX-2) selective inhibitors and nonselective NSAIDs are commonly used to treat osteoarthritis (OA) of the knee.

OBJECTIVE

The aim of this study was to compare the effectiveness of the lidocaine patch 5% with that of celecoxib 200 mg/d in the treatment of OA-related knee pain; however, the study was terminated prematurely by the sponsor because of tolerability concerns regarding the class of COX-2 selective inhibitors. A post hoc analysis of the available data is presented here.

METHODS

This multicenter, randomized, open-label, active-controlled, parallel-group study included patients >or=18 years of age with unilateral or bilateral moderate to severe OA of the knee. Patients were randomized to receive treatment with either the lidocaine patch 5% or celecoxib 200 mg/d. The primary efficacy end point was change from baseline to 12 weeks in the Western Ontario and McMaster Universities (WOMAC) OA Index pain subscale. Secondary end points included additional WOMAC subscales and Brief Pain Inventory (BPI) measures. Because this trial was prematurely terminated, a post hoc analysis was performed using a random pattern-mixture model of all observed cases of the intent-to-treat population.

RESULTS

A total of 143 patients were randomized to treatment (lidocaine patch 5%, 69 patients; mean [SD] age, 60.2 [11.4] years; 65.2% female; 66.7% white; weight, 94.1 [23.3] kg) or celecoxib 200 mg/d (74 patients; age, 58.2 [12.1] years; 63.5% female; 68.9% white; weight, 94.3 [22.5] kg). Baseline pain WOMAC OA subscale scores (lidocaine patch 5%, 12.087; celecoxib 200 mg/d, 12.514) and mean rates of change over time (baseline to week 2, -1.5916 vs -1.6513 per week; weeks 2-6, -0.0168 vs -0.119 per week; weeks 6-12, -0.1818 vs -0.1579 per week) were not significantly different between the 2 groups. Improvement in additional WOMAC subscales and in several BPI measures were not significantly different between the 2 groups. Treatment-related adverse events were reported in 8 patients in each treatment group (11.6% in the lidocaine patch 5% group and 10.8% in the celecoxib 200-mg/d group) and were considered mild or moderate in severity.

CONCLUSION

Statistically significant differences in effectiveness and tolerability were not found between these 2 treatments in these patients with OA knee pain.

The relationship between chondroprotective and antiinflammatory effects of Withania somnifera root and glucosamine sulphate on human osteoarthritic cartilage in vitro

Using a validated explant model of in vitro cartilage damage, the effects of aqueous extracts of Withania somnifera (Ashwagandha) root and glucosamine sulphate (GlcS) were tested on the levels of nitric oxide (NO) and glycosaminoglycans (GAGs) secreted by knee cartilage from chronic osteoarthritis (OA) patients. W. somnifera extracts significantly decreased NO release by explants from one subset of patients (antiinflammatory response) and significantly increased levels of NO and GAGs released by explants from the second subset ('non-responders'). This is the first study showing direct, statistically significant, antiinflammatory effects of W. somnifera on human OA cartilage. It also confirmed that glucosamine sulphate exhibited statistically significant, antiinflammatory and chondroprotective activities in human OA cartilage. However, these beneficial effects of GlcS were observed in cartilage explants from 50% of patients tested ('responders'). In contrast, glucosamine significantly increased secretion of NO but not GAGs in explants from the second subset of OA patients ('non-responders'). Cartilage explants from the 11 OA patients gave differential responses to both drugs. Patient samples which responded to the antiinflammatory effects of W. somnifera did not always give a similar response to glucosamine, and vice versa. Thus, this in vitro model of human cartilage damage provides qualitative and statistically significant, quantitative pre-clinical data on antiinflammatory and chondroprotective activities of antiarthritic drugs.