Systemic use of pentosan polysulphate in the treatment of osteoarthritis

Efficacy and safety of pentosan polysulfate sodium in people with symptomatic knee osteoarthritis and dyslipidaemia: protocol of the MaRVeL trial

INTRODUCTION

Knee osteoarthritis (OA) is the most prevalent arthritis type and a leading cause of chronic mobility disability. While pain medications provide only symptomatic pain relief; growing evidence suggests pentosan polysulfate sodium (PPS) is chondroprotective and could have anti-inflammatory effects in knee OA. This study aims to explore the efficacy and safety of oral PPS in symptomatic knee OA with dyslipidaemia.

METHODS AND ANALYSIS

MaRVeL is a phase II, single-centre, parallel, superiority trial which will be conducted at Royal North Shore Hospital, Sydney, Australia. 92 participants (46 per arm) aged 40 and over with painful knee OA and mild to moderate structural change on X-ray (Kellgren and Lawrence grade 2 or 3) will be recruited from the community and randomly allocated to receive two cycles of either oral PPS or placebo for 5 weeks starting at baseline and week 11. Primary outcome will be the 16-week change in overall average knee pain severity measured using an 11-point Numeric Rating Scale. Main secondary outcomes include change in knee pain, patient global assessment, physical function, quality of life and other structural changes. A biostatistician blinded to allocation groups will perform the statistical analysis according to the intention-to-treat principle.

ETHICS AND DISSEMINATION

The protocol has been approved by the NSLHD Human Research Ethics Committee (HREC) (2021/ETH00315). All participants will provide written informed consent online. Study results will be disseminated through conferences, social media and academic publications.

TRIAL REGISTRATION NUMBERS

Australian New Zealand Clinical Trial Registry (ACTRN12621000654853); U1111-1265-3750.

The effect of pentosan polysulfate sodium for improving dyslipidaemia and knee pain in people with knee osteoarthritis: A pilot study

Objective

To evaluate the efficacy and safety of pentosan polysulfate sodium (PPS, Elmiron®) for dyslipidaemia and knee osteoarthritis (OA) related symptoms.

Method

This was a single-arm, open-label, prospective, non-randomised pilot study. People with painful knee OA and a history of primary hypercholesterolemia were included. PPS was taken orally in a dosage of 10 ​mg/kg once every 4 days for 5 weeks for two cycles. There was 5 weeks of no medication between the cycles. The main outcomes included the change in lipidemia levels, the change in knee OA-related symptoms assessed by pain numerical rating scale (NRS) and Knee Osteoarthritis Outcome Score (KOOS), and knee MRI semi-quantitative score. The changes were analysed using paired t-tests.

Results

38 participants were included, with a mean age of 62.2 years. We found a statistically significant decrease in total cholesterol (from 6.23 ​± ​0.74 to 5.95 ​± ​0.77 ​mmol/L; P ​= ​0.01) and low-density lipoprotein (from 4.03 ​± ​0.61 to 3.82 ​± ​0.61 ​mmol/L; P ​= ​0.009) from baseline to week 16. Knee pain NRS was significantly reduced at weeks 6, 16 and 26 from 6.39 ​± ​1.33 to 4.18 ​± ​1.99, 3.63 ​± ​2.28 and 4.38 ​± ​2.55, respectively (P ​< ​0.001). However, there was no significant difference in terms of the primary outcome of triglyceride levels before and after treatment. The most common AEs were positive faecal occult blood tests, followed by headache and diarrhoea.

Conclusion

The findings suggest that PPS has promising effects on improving dyslipidaemia and symptomatic pain relief in people with knee OA.

Pentosan Polysulfate Affords Pleotropic Protection to Multiple Cells and Tissues

Pentosan polysulfate (PPS), a small semi-synthetic highly sulfated heparan sulfate (HS)-like molecule, shares many of the interactive properties of HS. The aim of this review was to outline the potential of PPS as an interventional therapeutic protective agent in physiological processes affecting pathological tissues. PPS is a multifunctional molecule with diverse therapeutic actions against many disease processes. PPS has been used for decades in the treatment of interstitial cystitis and painful bowel disease, it has tissue-protective properties as a protease inhibitor in cartilage, tendon and IVD, and it has been used as a cell-directive component in bioscaffolds in tissue engineering applications. PPS regulates complement activation, coagulation, fibrinolysis and thrombocytopenia, and it promotes the synthesis of hyaluronan. Nerve growth factor production in osteocytes is inhibited by PPS, reducing bone pain in osteoarthritis and rheumatoid arthritis (OA/RA). PPS also removes fatty compounds from lipid-engorged subchondral blood vessels in OA/RA cartilage, reducing joint pain. PPS regulates cytokine and inflammatory mediator production and is also an anti-tumor agent that promotes the proliferation and differentiation of mesenchymal stem cells and the development of progenitor cell lineages that have proven to be useful in strategies designed to effect repair of the degenerate intervertebral disc (IVD) and OA cartilage. PPS stimulates proteoglycan synthesis by chondrocytes in the presence or absence of interleukin (IL)-1, and stimulates hyaluronan production by synoviocytes. PPS is thus a multifunctional tissue-protective molecule of potential therapeutic application for a diverse range of disease processes.

Advances in the pharmaceutical treatment options for canine osteoarthritis

Canine osteoarthritis is a significant cause of pain in many dogs and can therefore compromise animal welfare. As the understanding of the biology and pain mechanisms underpinning osteoarthritis grows, so do the number of treatments available to manage it. Over the last decade, there have been a number of advances in the pharmaceutical treatment options available for dogs with osteoarthritis, as well as an increasing number of clinical trials investigating the efficacy of pre-existing treatments. This review aims to examine the current evidence behind pharmaceutical treatment options for canine osteoarthritis, including non-steroidal anti-inflammatory drugs, piprants, monoclonal antibodies, adjunctive analgesics, structure modifying osteoarthritis drugs and regenerative therapies.

Transient Postoperative Hemorrhage from Elbow Arthroscopy Portals following Intra-Articular Pentosan Polysulfate Sodium Injection

Four adult, client owned dogs with diagnosed bilateral elbow dysplasia undergoing elbow arthroscopy for removal of fragmented medial coronoid process were identified via a retrospective database search, who also received intra-articular administration of pentosan polysulfate sodium (PPS) (Cartrophen Vet, Biopharm Australia Pty Ltd., Bondi Junction, New South Wales). Dogs had postoperative administration of 5 ml PPS injected into each elbow joint following elbow arthroscopy. Within 1-3 hours of administration, each dog experienced hemorrhage from arthroscopy incisions that was determined to be independent of surgical trauma given lack of hemorrhage intraoperatively. Pressure bandages were placed, and the hemorrhage and elevated coagulation parameters resolved 12-18 hours following intra-articular injection. No further intervention was required, and the dogs were discharged 20-26 hours postoperatively. The purpose of this case series is to describe 4 dogs who experienced transient and focal hemorrhage following off-label intra-articular administration of pentosan polysulfate sodium (PPS). While this case series is limited due to small number of cases, results following bilateral, intra-articular injection of PPS support a transient systemic coagulopathy. Though this report represents administration of PSS via a route and at doses beyond that recommended on the label, results suggest that administration of PSS in the manner described in this report should be avoided.

Acute and severe haemorrhage following pentosan polysulfate injection in a Cornish Rex

Case summary

A 14-year-old male castrated Cornish Rex cat was referred for lethargy progressing rapidly to collapse in the hours following a subcutaneous injection of a product containing 100 mg/ml pentosan polysulfate sodium and 168 mg/ml glucosamine. Physical examination revealed the cat to be in hypotensive shock with swelling and interstitial oedema around the cranial thorax and caudal cervical regions without cutaneous haemorrhage. Initial diagnostics revealed a severe anaemia (packed cell volume 11%) which later deteriorated further, necessitating a blood transfusion and aggressive fluid therapy. Post-transfusion, the patient remained dyspnoeic and subsequent diagnostics found evidence of pre-existing cardiomyopathy and congestive heart failure. The cat was euthanased 24 h following presentation due to increasing dyspnoea. Post-mortem findings were of severe subcutaneous and intermuscular haemorrhage over the neck and thorax, among other changes. There were no detectable levels of coumarin anticoagulants in the liver.

Relevance and novel information

This is the first reported case of acute subcutaneous and intermuscular haemorrhage of this severity suspected to be related to the off-label use of an injectable product containing pentosan polysulfate in a cat. Given the popularity of its use for feline arthritis, there is a need for large-scale clinical trials to evaluate the safety and efficacy of products containing pentosan polysulfate for cats, and any side effects to be reported.

Repurposing pentosan polysulfate sodium as hyaluronic acid linked polyion complex nanoparticles for the management of osteoarthritis: A potential approach

Osteoarthritis is still a disease burden for pharmaceutical scientists and strategy makers. It is associated with the chronic inflammation of joints especially weight-bearing joints like knee, hip, backbone, and phalanges. NSAIDs that are used for the management of inflammation associated with osteoarthritis have high side effects related to gastric upset, gastric ulcer, and long term treatment associated with liver and kidney damage. Nanotechnology has gained a huge scope for the management of arthritis as it can reach out to the deep inside the cell and alter cellular physiology as desired. The present study hypothesizes the use of polyion complex nanoparticles of hyaluronic acid linked Pentosan polysulfate sodium, a disease-modifying agent for the treatment of osteoarthritis administered through transdermal route. The hypothesis involves the use of drug repurposing as the drug was initially approved for interstitial cystitis, a condition of the urinary bladder associated with pain and swelling. Being very low oral bioavailability and gastric irritation profile, the transdermal route would be beneficial. To overcome the problem associated with the oral route, there is a need for the targeted approach that will particularly reach at inflammatory sites. Thereby transdermal delivery of hyaluronic acid linked Pentosan polysulfate sodium through polyion complex nanoparticle therapy will be a novel therapeutic approach to combat osteoarthritis.

In-depth structural characterization of pentosan polysulfate sodium complex drug using orthogonal analytical tools

Rapid advances have been made in developing analytical technologies for characterization of highly heterogeneous active ingredients of complex drugs, such as pentosan polysulfate (PPS), active ingredient of the drug Elmiron®, approved by the Food and Drug Administration and marketed in the United States to treat interstitial cystitis. PPS sulfated polysaccharides comprise of a repeat unit of β(1-4)-D-xylopyranoses randomly substituted by 4-O-methyl-glucopyranosyluronic acid. To define the critical quality attributes (CQAs) of such a complex drug, it is critical to develop an approach that integrates data from orthogonal analytical methodologies. Here, we developed an approach integrating diverse analytical tools including gel permeation chromatography, LC/ESI-MS and NMR to measure CQAs of PPS. The proposed mathematical framework integrates the data from these diverse analytical methods as function of PPS chain length and building blocks. Our approach would facilitate in establishing a scientific foundation for comparative characterization of drug products with complex active ingredients.

Evaluation of the Release Kinetics of a Pharmacologically Active Substance from Model Intra-Articular Implants Replacing the Cruciate Ligaments of the Knee

Implants are readily applied as a convenient method of therapy. There is great interest in the prolonged release of active substances from implants. The objective of this work was to evaluate the dissolution kinetics of steroidal anti-inflammatory preparation (SAP) released from novel implants, and to test the influence of the technology on SAP release kinetics. The proposed long-acting preparations may overcome difficulties resulting from repeated injections and often visits to ambulatory clinic, as the stabilizing function of the artificial ligament would be enriched with pharmacological activity. The potential advantages provided by the new coatings of knee implants include the continuous, sustained, and prolonged release of an active substance. The study was carried out using a modified United States Pharmacopoeia (USP) apparatus 4. The amount of SAP was measured spectroscopically. It was revealed that the transport of the drug was mainly a diffusion process. The drug release kinetics was analyzed using zero-, first-, and second-order kinetics as well as Korsmeyer-Peppas, Higuchi, and Hixon-Crowell models. The highest values of the release rate constants were k0 = (7.49 ± 0.05) × 10-5 mg × min-1, k1 = (6.93 ± 0.05) × 10-6 min-1, and k2 = (7.70 ± 0.05) × 10-7 mg-1 × min-1 as calculated according to zero-, first-, and second-order kinetics equations, respectively. The values of the rate constants obtained for the slowest process were k0 = (3.63 ± 0.06) × 10-5 mg × min-1, k1 = (2.50 ± 0.03) × 10-6 min-1, and k2 = (2.80 ± 0.03) × 10-7 mg-1 × min-1. They may suggest the possibility of sustained release of betamethasone from the system. Due to the statistical analysis, differences were observed between most of the studied implants. Incubation, temperature, time of stabilization of layers, and the method of SAP deposition on the matrix affected the drug release.

Conservative Management of Hip Dysplasia

Hip dysplasia (HD) is a common orthopedic condition seen in small animal patients that leads to osteoarthritis of the coxofemoral joint. The disease can be managed conservatively or surgically. The goals of surgical treatment in the immature patient are to either prevent the clinical signs of HD or to prevent or slow the progression of osteoarthritis. In mature patients surgery is used as a salvage procedure to treat debilitating osteoarthritis. Conservative management can be used in dogs with mild or intermittent clinical signs and includes nutritional management and weight control, exercise modification, physical rehabilitation, pain management and disease-modifying agents.

Therapeutic options for the treatment of chronic pain in dogs

Chronic pain is a widely recognised problem in humans and is being increasingly recognised as a significant problem in dogs. Whilst a large number of therapies are described and utilised to treat chronic pain in dogs, there is a severe shortage of evidence to guide practitioners in selection of treatments. Until more evidence becomes available, practitioners should adopt a cautious approach, utilising licensed treatments first when possible. Non-pharmacological therapies should be incorporated into the chronic pain management plan whenever possible. Given the probable prevalence of chronic pain in dogs there is an urgent need for research to identify effective treatments.

Systematic review of the management of canine osteoarthritis

This review assesses the evidence for the efficacy of therapies used in the management of osteoarthritis in dogs on the basis of papers published in peer-reviewed journals in English between 1985 and July 2007. Sixty-eight papers were identified and evaluated. They considered four alternative therapies, one use of functional food, two intra-articular agents, six nutraceutical agents, 21 pharmacological agents, two physical therapies, three surgical techniques and two combinations of weight control. There was a high level of comfort (strong evidence) for the efficacy of carprofen, firocoxib and meloxicam, and a moderate level of comfort for the efficacy of etodolac in modifying the signs of osteoarthritis. There was a moderate level of comfort for the efficacy of glycosaminoglycan polysulphate, licofelone, elk velvet antler and a functional food containing green-lipped mussel for the modification of the structures involved in the disease. There was weak or no evidence in support of the use of doxycycline, electrostimulated acupuncture, extracorporeal shockwave therapy, gold wire acupuncture, hyaluronan, pentosan polysulphate, P54FP (extract of turmeric), tiaprofenic acid or tibial plateau levelling osteotomy.

Evaluation of Pentosan Polysulfate Sodium in the Postoperative Recovery from Cranial Cruciate Injury in Dogs: A Randomized, Placebo-Controlled Clinical Trial

OBJECTIVE

To evaluate the efficacy of pentosan polysulfate (PPS) for improving the recovery period and mitigate the progression of osteoarthritis (OA) of the canine stifle after extracapsular stabilization of cranial cruciate ligament (CCL) injuries.

STUDY DESIGN

Randomized, blinded, placebo-controlled clinical trial.

ANIMALS

Dogs (n=40) with unilateral CCL instability.

METHODS

Each dog had an extracapsular stabilization of the stifle with or without partial meniscectomy. Dogs were divided into 4 groups based on preoperative radiographic assessment and whether a partial meniscectomy was performed. Dogs were randomly assigned to either (3 mg/kg) PPS or placebo treatment in each group, and then injected subcutaneously weekly for 4 weeks. Lameness, radiographic changes, biological marker concentration in blood and urine, and ground reaction forces (GRFs) were collected preoperatively, and at 6, 12, 24, and 48 weeks. Data were analyzed within and between groups using repeated measures ANOVA; P<.05 was considered significant.

RESULTS

No adverse reactions to PPS were reported. Thirty-nine dogs completed a minimum of 24-weeks follow-up and 33 dogs completed 48 weeks. All dogs clinically improved after surgery without differences in lameness score, vertical GRFs, or radiographic progression. Grouped and evaluated only by initial radiographic score, PPS-treated dogs improved significantly faster in braking GRFs than placebo-treated dogs. In dogs with partial meniscectomies, urine deoxypyridinoline, and serum carboxy-propeptide of type II collagen were significantly increased at 6 weeks in placebo-treated dogs compared with PPS-treated dogs.

CONCLUSIONS

PPS administered after stabilization of the cruciate deficient stifle may prove to be a useful adjunctive treatment option, although further studies are necessary to substantiate this claim.

Systematic review of clinical trials of treatments for osteoarthritis in dogs

OBJECTIVE

To identify and critically evaluate the quality of evidence of the most commonly used pharmacologic, nutraceutical, and purported slow-acting drugs of osteoarthritis for the management of osteoarthritis in dogs by use of the FDA's evidence-based medicine scoring system.

DESIGN

Systematic review.

SAMPLE POPULATION

16 clinical trials.

PROCEDURES

A broad bibliographic search was performed prior to May 2006. Inclusion criteria focused on prospective trials evaluating commonly used medical treatment interventions for the management of osteoarthritis in dogs and published in peer-reviewed journals. The analysis consisted of the following: study design rating, quality factor rating, quantity rating, consistency rating, relevance to disease risk reduction rating, and cumulative strength of evidence ranking.

RESULTS

4 trials evaluating meloxicam were rated as type I. Three trials evaluating carprofen were rated as type I, and 2 trials were rated as type III. One trial evaluating each of the following agents was rated as type 1: etodolac; P54FP; polysulfated glycosaminoglycan; and a combination of chondroitin sulfate, glucosamine hydrochloride, and manganese ascorbate. Two trials evaluating pentosan polysulphate and 2 trails evaluating green-lipped mussels were rated as type I. One trial evaluating hyaluronan was rated as type III.

CONCLUSIONS AND CLINICAL RELEVANCE

A high level of comfort exists for meloxicam that the claimed relationship is scientifically valid and that its use is clinically efficacious for the treatment of osteoarthritis in dogs. A moderate level of comfort exists for carprofen; etodolac; pentosan polysulphate; green-lipped mussels; P54FP; polysulfated glycosaminoglycans; and a combination of chondroitin sulfate, glucosamine hydrochloride, and manganese ascorbate. An extremely low level of comfort exists for hyaluronan.

Pharmaceutical and nutraceutical management of canine osteoarthritis: present and future perspectives

Osteoarthritis (OA) is one of the most common chronic musculoskeletal diseases and causes of lameness in the dogs. The osteoarthritic disease process involves the entire synovial joint, encompassing the synovium, cartilage and underlying bone. Joint failure results from an abnormal mechanical strain causing damage to normal tissue or failure of pathologically impaired articular cartilage and bone under the influence of normal physiological strain or a combination of both. In both cases, the end point is cartilage loss and joint impairment. Osteoarthritic chondrocytes show an altered phenotype characterised by an excess production of catabolic factors, including metalloproteinases and reactive oxygen species. These factors constitute potential therapeutic targets and some new drugs and nutraceuticals have been proposed to promote the return to homeostasis. Until now, the therapeutic management of OA in dogs has been dominated by nonsteroidal anti-inflammatory drugs, but some new compounds, including diacerhein, with potential structure-modifying effects, are already used to treat OA in humans and could be helpful to manage OA in the dog. In addition, novel nutraceuticals, such as avocado/soybean unsaponifiable substances, have shown symptomatic effects in knee OA in humans, and could offer an alternative to prevent OA progression. This paper provides an overview of recent discoveries in the pathophysiology and in the therapeutic management of osteoarthritis in dogs.

Use of nutraceuticals and chondroprotectants in osteoarthritic dogs and cats

Chondroprotectants and nutraceuticals have become attractive adjunctive or alternative treatments for cats and dogs suffering from osteoarthritis. Osteoarthritic patients can be managed satisfactorily in most situations with optimization of body condition, exercise modification, anti-inflammatory therapy, and the use of chondroprotectants agents. Presently, recommendations cannot be made as to which chondroprotectant is best for each dog and cat afflicted with osteoarthritis. Head-to-head comparisons of these products have not been made, and it is not known when the different mediators of osteoarthritis play an important role. Currently, the best recommendation is to use products that have well-designed experimental and clinical research evaluating efficacy and safety, and products that are manufactured under the high quality standards practiced by the pharmaceutical industry.

Safety of Cartrophen Vet in the dog: review of adverse reaction reports in the UK

Suspected adverse reactions (SARs) reported for Cartrophen Vet (100 mg sodium pentosan polysulphate/ml) to the Veterinary Medicines Directorate in the UK for the period January 1991 to October 1999 were reviewed. Of the 161 reports, 28 were probably product related, 54 were possibly product related, 71 were unlikely to be related and eight were unclassified. An estimated real incidence of adverse reactions probably and possibly associated with Cartrophen Vet of 0.074 per cent on an individual dose basis was calculated (assuming only 10 per cent were documented due to underreporting). Sixty-two SARs (38.5 per cent) documented emesis, 22 (35.5 per cent) of which were product related (onset five to 15 minutes after administration). Sixty-eight SARs (42.2 per cent) documented general changes to demeanour, 10 (14.7 per cent) were product related (lethargy and/or mild depression and/or mild inappetence lasting up to two days after administration). Six SARs were considered likely to be associated with concurrently administered carprofen. Cartrophen Vet had a low incidence of side effects that were mild and transitory.

Randomised, double-blind, placebo-controlled parallel group study of P54FP for the treatment of dogs with osteoarthritis

P54FP is an extract of Indian and Javanese turmeric, Curcuma domestica and Curcuma xanthorrhiza respectively, which contains a mixture of active ingredients including curcuminoids and essential oils. A randomised, double-blind, placebo-controlled, parallel group clinical trial of P54FP as a treatment for osteoarthritis of the canine elbow or hip was conducted to assess its efficacy and safety. Sixty-one client-owned dogs with osteoarthritis were recruited through first-opinion practices and examined at a single centre. After a two-week wash-out period, they were randomly allocated to receive P54FP or a placebo orally twice daily for eight weeks, and were re-examined after four, six and eight weeks of treatment. The effectiveness of the treatment was assessed in terms of the peak vertical force (PVz) and vertical impulse of the affected limbs, as measured with a force platform, by clinical assessments of lameness and joint pain by the investigators, and overall assessments of the response to treatment by the investigators and the owners. The results from 25 P54FP-treated dogs and 29 placebo-treated dogs showed that there was no statistically significant difference between the groups in terms of the PVz of the affected limb. The investigators' overall assessment showed a statistically significant treatment effect in favour of P54FP (P=0.012), but the owners' assessment just failed to reach statistical significance (P=0.063). No serious adverse effects were recorded, but two P54FP-treated dogs and four placebo-treated dogs were withdrawn from the study because their condition deteriorated.

Optimisation for the separation of the oligosaccharide, sodium Pentosan Polysulfate by reverse polarity capillary zone electrophoresis using a central composite design

The separation by reverse polarity capillary zone electrophoresis of the therapeutically developed sodium salt of Pentosan Polysulfate was optimised through the analysis of response surface methodologies, modeled using a central composite design. The optimisation investigated injection pressure, injection time and voltage and the effect of the conditions on retention times, peak areas, separation efficiency and the method sensitivity. The overall goal was to develop the most sensitive results with no decrease in separation efficiency. The following results were obtained: (1) retention times generally decreased as injection pressure, injection time and voltage increased, injection time having the least effect; (2) as expected peak areas increased as injection pressure and injection time increased but decreased as voltage increased; (3) separation efficiencies generally increased as injection pressure and injection time decreased, with voltage having almost no effect. For the optimum condition, the sample was introduced at the inlet vial at the cathode hydrodynamically, at optimal setting of 44 s at 35 mbar. The optimal voltage was -20 kV. In comparison with other methods, the optimum showed increased sensitivity, resolution and separation efficiency. Repeatability studies were performed on the optimum parameter conditions. Relative standard deviation values obtained were between 0.9 and 5.4%.

Biosensor analysis of the molecular interactions of pentosan polysulfate and of sulfated glycosaminoglycans with immobilized elastase, hyaluronidase and lysozyme using surface plasmon resonance (SPR) technology

Pentosan polysulfate (NaPPS) and chondroitin sulfates (ChSs) have recently been shown to exhibit both symptom and disease modifying activities in osteoarthritis (OA), but their respective mechanisms of action are still the subject of conjecture. Excessive catabolism of joint articular cartilage is considered to be responsible for the initiation and progression of OA but the abilities of these drugs to mitigate this process has received only limited attention. Human neutrophil elastase (HNE) is a proteinase, which can degrade the collagens and proteoglycans (PGs) of the cartilage directly or indirectly by activating latent matrix metalloproteinases. Hyaluronidase (HAase) is an endoglycosidase, which degrades glycosaminoglycans including hyaluronan, which provides the aggregating component of the PG aggrecan complex. In the present study the molecular interactions between the NaPPS, ChSs and some other sulfated polysaccharides with immobilized HNE, HAase or lysozyme (a cationic protein implicated in PG metabolism) were studied using a SPR biosensor device-BIAcore2000. The above three enzymes were covalently immobilized to a biosensor chip CM5 separately using amine coupling. The binding affinity of each sulfated polysaccharide and the kinetics of NaPPS over the concentration range of 0.3-5.0 microg/ml were determined. The inhibition of HNE by the sulfated polysaccharides as determined using the synthetic substrate succinyl-Ala-Ala-Val-nitroanilide (SAAVNA) in a functional assay was compared with their respective binding affinities for this proteinase using the BIAcore system. The results obtained with the two independent techniques showed good correlation and indicated that the degree and ring positions of oligosaccharide sulfation were major determinants of enzyme inhibitory activity. The observed difference in order of binding affinities of the drugs to the immobilized HNE, HAase and lysozyme suggests a conformational relationship, in addition to the charge interactions between the sulfate esters of the polysaccharides and the cationic amino acids of the enzymes. Significantly, the SPR biosensor technology demonstrated that small differences among sulfated polysaccharides, even subtle variations among different NaPPS batches, could be readily detected. The SPR technology therefore offers not only a sensitive and reproducible method for ranking noncompetitive enzyme inhibitors for drug discovery but a rapid and quantitative bioassay for monitoring batch consistency of manufacture.

S. Sulfato de condroitina e hialuronato de sódio no tratamento da doença articular degenerativa experimental em cães: aspectos clínicos e radiológicos

Avaliaram-se clínica e radiograficamente os efeitos do sulfato de condroitina e do hialuronato de sódio no tratamento da articulação femorotibiopatelar de cães com doença articular degenerativa (DAD) induzida experimentalmente. Foram utilizados 15 cães, sem raça definida, de ambos os sexos, pesando entre 18 e 25 kg, submetidos à secção artroscópica do ligamento cruzado cranial (LCCr) para desestabilização articular e indução da DAD. Após três semanas de instabilidade articular, o LCCr foi substituído utilizando-se a técnica intra-articular com emprego da fáscia lata. Os animais foram divididos em três grupos de cinco. Nos do grupo I fez-se somente a substituição do LCCr. Os do grupo II receberam 24mg/animal de sulfato de condroitina, via IM, de cinco em cinco dias, totalizando seis aplicações. Os do grupo III foram tratados com hialuronato de sódio na dose de 20mg/animal, via IV, de cinco em cinco dias, num total de três aplicações. Os animais foram observados por 90 dias, e avaliados clinicamente quanto à claudicação, à capacidade de suportar peso no membro afetado, à mensuração da atrofia muscular e à amplitude de movimento articular. Ao final, foram encaminhados para novo exame radiográfico. Os resultados demonstraram que os animais que receberam hialuronato de sódio apresentaram menor grau de claudicação quando comparados com os demais. Ao exame radiográfico observaram-se osteofitose periarticular e esclerose óssea subcondral. Essas alterações foram evidenciadas de forma mais acentuada nos animais tratados com hialuronato de sódio. Clinicamente, pôde-se observar melhor resultado com o hialuronato de sódio do que nos demais grupos, possivelmente devido à sua maior ação na membrana sinovial, reduzindo a dor e o grau de claudicação. O exame radiográfico não foi compatível com a sintomatologia clínica nos cães tratados com hialuronato de sódio.

Effects of anti-arthritic drugs on proteoglycan synthesis by equine cartilage

The concentration-effect relationships of phenylbutazone, indomethacin, betamethasone, pentosan polysulphate (PPS) and polysulphated glycosaminoglycan (PSGAG), on proteoglycan synthesis by equine cultured chondrocytes grown in monolayers, and articular cartilage explants were measured. The effect of PSGAG on interleukin-1beta induced suppression of proteogycan synthesis was also investigated. Proteoglycan synthesis was measured by scintillation assay of radiolabelled sulphate (35SO4) incorporation. Polysulphated glycosaminoglycan and PPS stimulated proteoglycan synthesis in chondrocyte monolayers in a concentration-related manner with maximal effects being achieved at a concentration of 10 microg/mL. Polysulphated glycosaminoglycan reversed the concentration-related suppression of proteoglycan synthesis induced by interleukin-1beta. Neither PSGAG nor PPS exerted significant effects on radiolabel incorporation in cartilage explants. Betamethasone suppressed proteoglycan synthesis by both chondrocytes and explants at high concentrations (0.1-100 microg/mL), but the effect was not concentration-related. At low concentrations (0.001-0.05 microg/mL) betamethasone neither increased nor decreased proteoglycan synthesis. Phenylbutazone and indomethacin increased radiolabel incorporation in chondrocyte cultures but not in cartilage explants at low (0.1, 1 and 10 microg/mL), but not at high (20 and 100 microg/mL) concentrations. These findings may be relevant to the clinical use of these drugs in the treatment of equine disease.

Plasma and synovial fluid concentrations of calcium pentosan polysulphate achieved in the horse following intramuscular injection

Results from in vitro studies have indicated that calcium pentosan polysulphate (CaPPS) may be of therapeutic value in osteoarthritis (OA) in the horse. However, no controlled clinical trials using this drug in equine OA have yet been reported. If CaPPS is to be developed for such use, the relationship between the proposed i.m. dose of CaPPS to be used and the concentrations of drug attained in plasma and synovial fluid of the target joint should first be established. An investigation was undertaken to determine these concentrations after a single 2 mg/kg i.m. injection of CaPPS. Blood and synovial fluid samples were taken from 6 healthy, sound horses following i.m. CaPPS administration. Concentrations of CaPPS measured in the synovial fluid were, on the basis of published studies, sufficient to elicit a potential therapeutic effect on synoviocyte metabolism, and possibly also to stimulate proteoglycan synthesis and reduce matrix metalloproteinase activities in articular cartilage. It would therefore seem justified to investigate further the therapeutic effect of CaPPS in OA in the horse.

Evaluation of the clinical efficacy of meloxicam in cats with painful locomotor disorders

The ability of two non-steroidal anti-inflammatory drugs to modify the clinical manifestations of pain associated with locomotor disease was assessed. Sixty-nine cats with acute or chronic locomotor disorders were recruited from 14 first opinion UK veterinary practices and randomly allocated to one of two treatment groups. Group A received meloxicam drops (0.3 mg/kg orally on day 1 followed by 0.1 mg/kg daily for four more consecutive days) and group B received ketoprofen tablets (1.0 mg/kg orally once daily for five days). Each cat underwent a full clinical examination before treatment, 24 hours after initiation of treatment and 24 hours after completion of treatment. General clinical parameters (demeanour and feed intake) and specific locomotor parameters (weightbearing, lameness, local inflammation and pain on palpation) were scored using a discontinuous scale scoring system. The two groups did not differ in terms of age, weight, gender distribution or duration of clinical signs; nor did they differ in terms of general clinical or specific locomotor scores pretreatment. Both treatment regimens resulted in a significant improvement in demeanour, feed intake and weightbearing, and a significant reduction in lameness, pain on palpation and inflammation. No significant difference was observed between the two treatment groups with respect to any of the parameters measured and both treatments were associated with minimal observed side effects. Meloxicam and ketoprofen were found to be effective analgesics and well tolerated in cats with acute or chronic locomotor disorders when administered for short-term treatment (five days) in such cases. However, meloxicam was assessed to be significantly more palatable than ketoprofen.

The effect of three different doses of sodium pentosan polysulphate on haematological and haemostatic variables in adult horses

OBJECTIVE

To evaluate the effects of three different doses of sodium pentosan polysulphate (PPS) on haematological and haemostatic variables in adult horses.

DESIGN

Eight adult standardbred horses were used. All horses received a single injection of 0, 3, 6, and 10 mg/kg of PPS at the beginning of each treatment week for 4 weeks so that by the end of the study all horses had received all four doses of PPS. Blood samples were collected at 0, 1, 2, 3, 4, 6, 8, 12, 24, 48, and 168 h after each weekly injection of PPS. Variables measured were packed cell volume, haemoglobin, red blood cell count, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelet count, white cell count, neutrophil count, lymphocyte count, eosinophil count, monocyte count, serum protein, fibrinogen, prothrombin time, and activated partial thromboplastin time (PTT). Data were analysed using an ANOVA. Significance was set at P < 0.05.

RESULTS

There was a dose-dependent increase in PTT. A significant increase in PTT occurrred in all treatment groups when compared to horses receiving 0 mg/kg in which there was no change over time. The PTT values all returned to baseline by 48 h after treatment. The mean neutrophil count was higher 3 h after treatment when compared to time 0. Horses receiving 3 mg/kg of PPS had a higher lymphocyte count 4 h after injection, and those receiving 6 and 10 mg/kg had higher counts at 3,4,6 and 8 h after injection when compared to time 0. At 8 h after injection horses receiving 6 and 10 mg PPS had higher lymphocyte counts than horses not receiving PPS.

CONCLUSIONS

PPS causes a dose-dependent prolongation of PTT in horses. At the dose rates currently recommended for treatment of joint problems in horses this increase was small and remained elevated from baseline for up to 24 h. Based on these findings doses of PPS up to 3 mg/kg should not be administered to horses within 24 h of high stress activities or where physical injury may occur.

Calcium pentosan polysulfate inhibits the catabolism of aggrecan in articular cartilage explant cultures

OBJECTIVE

The catabolism of aggrecan and loss of aggrecan fragments from articular cartilage is a key event in the pathogenesis of arthritic diseases such as osteoarthritis. The catabolism of aggrecan is mediated by the specific proteolytic activity termed aggrecanase. The aim of this study was to investigate the effect of the chondroprotective agent calcium pentosan polysulfate (CaPPS) on the aggrecanase-mediated catabolism of aggrecan.

METHODS

The catabolism of 35S-labeled aggrecan and loss of tissue glycosaminoglycans (GAGs) were investigated using bovine articular cartilage explant cultures maintained in medium containing varying concentrations of CaPPS (1-100 microg/ml) in the presence or absence of 10(-6)M retinoic acid or 7 ng/ml recombinant human interleukin-1alpha (rHuIL-1alpha). In addition, the effect of CaPPS on the degradation of aggrecan monomers by aggrecanase activity present in conditioned medium from joint capsule explant cultures was investigated.

RESULTS

CaPPS inhibited the catabolism of 35S-labeled aggrecan in a dose-dependent manner, particularly when retinoic acid or rHuIL-1alpha was used to stimulate aggrecan catabolism. These effects were reflected in the tissue levels of GAG remaining in these cultures at the end of the experiment. CaPPS inhibited the degradation of aggrecan monomers by soluble aggrecanase activity.

CONCLUSION

CaPPS inhibits the catabolism of aggrecan by articular cartilage in a dose-dependent manner, particularly when the processes responsible for aggrecan loss are stimulated. This effect occurs, at least in part, through direct inhibition of aggrecanase activity. CaPPS did not adversely affect overall chondrocyte metabolism, as shown by the incorporation of 35S-sulfate and 3H-leucine into macromolecules and by lactate production in cartilage explant cultures.

Sulfated glycosaminoglycans and glucosamine may synergize in promoting synovial hyaluronic acid synthesis

High-molecular-weight hyaluronic acid (HA) produced by the synovium may function physiologically to aid preservation of cartilage structure and prevent arthritic pain; both the size and concentration of HA in synovial fluid are diminished in osteoarthritis (OA). Glucosamine therapy for OA can be expected to increase synovial HA production by providing rate-limiting substrate. In addition, certain sulfated glycosaminoglycans and polysaccharides - including chondroitin sulfate (CS), dermatan sulfate, and pentosan polysulfate - stimulate synovial HA production, apparently owing to a hormone-like effect triggered by the binding of these polymers to membrane proteins of synovial cells. Surprisingly, a significant proportion of orally administered CS is absorbed as intact polymers - apparently by pinocytosis. These considerations may rationalize clinical studies concluding that oral CS provides slow-onset but durable pain relief and functional improvement in OA. The possibility that oral glucosamine and CS may interact in a complementary or synergistic fashion to improve synovial fluid HA content in OA should be assessed in clinical studies, and the potential of adjunctive CS administration to improve the clinical response achievable with optimal intakes of glucosamine should likewise be evaluated. In light of the fact that the synovium virtually functions as a 'placenta' for cartilage, focusing on synovium as the target for therapeutic intervention in OA may be a rational strategy.

Efficacy of oral calcium pentosan polysulphate for the treatment of osteoarthritis of the canine stifle joint secondary to cranial cruciate ligament deficiency

The efficacy of calcium pentosan polysulphate (CaPPS) as a slow-acting drug for the treatment of osteoarthritis of the canine stifle joint, secondary to cranial cruciate ligament deficiency, was tested in a double-blind, placebo-controlled clinical trial over a period of one year. Dogs with the deficiency were treated surgically, matched for bodyweight, and randomly assigned to treatment or placebo groups. Active treatment began six weeks postoperatively and consisted of 10 mg/kg CaPPS orally, once weekly for four weeks, repeated every 12 weeks. The outcome was assessed in terms of function by the dogs' owners, by the radiographical grading of the osteoarthritis, and by the measurement of total sulphated glycosaminoglycans and the 5D4 epitope of keratan sulphate in the synovial fluids of affected joints. There were no differences either in functional outcome or in the radiographical progression of osteoarthritis between the two groups. Fifty-four weeks after surgery, the concentration of 5D4 in synovial fluid (expressed as change from baseline values) had decreased significantly in the treatment group compared with the placebo group (P=0.03).

The pathobiology of osteoarthritis and the rationale for the use of pentosan polysulfate for its treatment

OBJECTIVES

Structure-modifying osteoarthritis (OA) drugs (SMOADs) may be defined as agents that reverse, retard, or stabilize the underlying pathology of OA, thereby providing symptomatic relief in the long-term. The objective of this review was to evaluate the literature on sodium pentosan polysulfate (NaPPS) and calcium pentosan polysulfate (CaPPS), with respect to the pathobiology of OA to ascertain whether these agents should be classified as SMOADs.

METHODS

Published studies on NaPPS and CaPPS were selected on the basis of their relevance to the known pathobiology of OA, which also was reviewed.

RESULTS

Both NaPPS and CaPPS exhibit a wide range of pharmacological activities. Of significance was the ability of these agents to support chondrocyte anabolic activities and attenuate catabolic events responsible for loss of components of the cartilage extracellular matrix in OA joints. Although some of the anti-catabolic activities may be mediated through direct enzyme inhibition, NaPPS and CaPPS also have been shown to enter chondrocytes and bind to promoter proteins and alter gene expression of matrix metalloproteinases and possibly other mediators. In rat models of arthritis, NaPPS and CaPPS reduced joint swelling and inflammatory mediator levels in pouch fluids. Moreover, synoviocyte biosynthesis of high-molecular-weight hyaluronan, which is diminished in OA, was normalized when these cells were incubated with NaPPS and CaPPS or after intraarticular injection of NaPPS into arthritic joints. In rabbit, canine, and ovine models of OA, NaPPS and CaPPS preserved cartilage integrity, proteoglycan synthesis, and reduced matrix metalloproteinase activity. NaPPS and CaPPS stimulated the release of tissue plasminogen activator (t-PA), superoxide dismutase, and lipases from vascular endothelium while concomitantly decreasing plasma levels of the endogenous plasminogen activator inhibitor PAI-1. The net thrombolytic and lipolytic effects exhibited by NaPPS and CaPPS may serve to improve blood flow through subchondral capillaries of OA joints and improve bone cell nutrition. In geriatric OA dogs, NaPPS and CaPPS reduced symptoms, as well as normalized their thrombolytic status, threshold for platelet activation, and plasma triglyceride levels. These hematologic parameters were shown to be abnormal in OA animals before drug treatment. Similar outcomes were observed in OA patients when CaPPS or NaPPS were given orally or parenterally in both open and double-blind trials.

CONCLUSIONS

The data presented in this review support the contention that NaPPS and CaPPS should be classified as SMOADs. However, additional long-term clinical studies employing methods of assessing joint structural changes will be needed to confirm this view.

Slow-acting, disease-modifying osteoarthritis agents

There is evidence to suggest that tetracyclines have benefit beyond their antimicrobial activity. The ability to inhibit metalloproteinase activity may provide a disease-modifying effect in OA, and available data suggest that further investigation is warranted. Controlled, double-blind, prospective clinical studies have not been completed. The canine cruciate ligament transection model studies are frequently cited as the most convincing in vivo evidence of a benefit of oral tetracycline therapy for the treatment of OA. Until more evidence becomes available, the use of tetracyclines as therapeutic agents for OA should be considered investigational.

Outcome assessment in clinical trials involving medical management of osteoarthritis in small animals

The goal of any clinical trial involving modulation of osteoarthritis is to assess the efficacy of a proposed therapy. This article attempts to provide some insight into assessing the outcome of clinical trials involving the management of osteoarthritis and reviews select key areas within clinical trials that need to be evaluated during critical analysis of any proposed therapeutic product.