Potential effects of chondroitin sulfate on joint swelling: a GAIT report

Galactosaminoglycans: Medical Applications and Drawbacks

Galactosaminoglycans (GalAGs) are sulfated glycans composed of alternating N-acetylgalactosamine and uronic acid units. Uronic acid epimerization, sulfation patterns and fucosylation are modifications observed on these molecules. GalAGs have been extensively studied and exploited because of their multiple biomedical functions. Chondroitin sulfates (CSs), the main representative family of GalAGs, have been used in alternative therapy of joint pain/inflammation and osteoarthritis. The relatively novel fucosylated chondroitin sulfate (FCS), commonly found in sea cucumbers, has been screened in multiple systems in addition to its widely studied anticoagulant action. Biomedical properties of GalAGs are directly dependent on the sugar composition, presence or lack of fucose branches, as well as sulfation patterns. Although research interest in GalAGs has increased considerably over the three last decades, perhaps motivated by the parallel progress of glycomics, serious questions concerning the effectiveness and potential side effects of GalAGs have recently been raised. Doubts have centered particularly on the beneficial functions of CS-based therapeutic supplements and the potential harmful effects of FCS as similarly observed for oversulfated chondroitin sulfate, as a contaminant of heparin. Unexpected components were also detected in CS-based pharmaceutical preparations. This review therefore aims to offer a discussion on (1) the current and potential therapeutic applications of GalAGs, including those of unique features extracted from marine sources, and (2) the potential drawbacks of this class of molecules when applied to medicine.

Access to Highly Purified Chondroitin Sulfate for Appropriate Treatment of Osteoarthritis: A Review

Current pharmacological therapies for osteoarthritis are symptom-focused and aimed at controlling pain. However, currently approved symptom-modifying agents do not restore the structure and function of damaged joints. Symptomatic slow-acting drugs in osteoarthritis (SySADOAs), including the sulfated glycosaminoglycan, chondroitin sulfate, have shown promising beneficial effects on the pain and other symptoms of osteoarthritis, and some may also have a positive effect on cartilage, slowing the progression of joint deterioration in osteoarthritis. A highly-purified, standardized, pharmaceutical-grade preparation of chondroitin sulfate has shown activity in osteoarthritis and has become one of the most prescribed SySADOAs. However, in many countries, formulations of chondroitin sulfate of various sources and purity are available as food supplements or nutraceuticals. As the effects of chondroitin sulfate could vary according to the characteristics of the chondroitin sulfate employed, including source, purity, or structural organization, clinical data from well-designed studies of pharmaceutical-grade chondroitin sulfate should not be extrapolated to support clinical efficacy claims of food supplements; nor should results from trials of chondroitin sulfate-containing food supplements be used to draw conclusions about the efficacy of pharmaceutical-grade chondroitin sulfate. This article reviews the evidence for the role of highly-purified pharmaceutical-grade chondroitin sulfate in the treatment of osteoarthritis and examines the efficacy and safety concerns of other formulations of chondroitin sulfate. Highly-purified pharmaceutical-grade chondroitin sulfate has mild-to-moderate efficacy in the treatment of symptomatic osteoarthritis, with clinically meaningful efficacy.

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.

Glucosamine and chondroitin for knee osteoarthritis: a double-blind randomised placebo-controlled clinical trial evaluating single and combination regimens

OBJECTIVE

To determine if the dietary supplements, glucosamine and/or chondroitin, result in reduced joint space narrowing (JSN) and pain among people with symptomatic knee osteoarthritis.

METHODS

A double-blind randomised placebo-controlled clinical trial with 2-year follow-up. 605 participants, aged 45-75 years, reporting chronic knee pain and with evidence of medial tibio-femoral compartment narrowing (but retaining >2 mm medial joint space width) were randomised to once daily: glucosamine sulfate 1500 mg (n=152), chondroitin sulfate 800 mg (n=151), both dietary supplements (n=151) or matching placebo capsules (n=151). JSN (mm) over 2 years was measured from digitised knee radiographs. Maximum knee pain (0-10) was self-reported in a participant diary for 7 days every 2 months over 1 year.

RESULTS

After adjusting for factors associated with structural disease progression (gender, body mass index (BMI), baseline structural disease severity and Heberden's nodes), allocation to the dietary supplement combination (glucosamine-chondroitin) resulted in a statistically significant (p=0.046) reduction of 2-year JSN compared to placebo: mean difference 0.10 mm (95% CI 0.002 mm to 0.20 mm); no significant structural effect for the single treatment allocations was detected. All four allocation groups demonstrated reduced knee pain over the first year, but no significant between-group differences (p=0.93) were detected. 34 (6%) participants reported possibly-related adverse medical events over the 2-year follow-up period.

CONCLUSIONS

Allocation to the glucosamine-chondroitin combination resulted in a statistically significant reduction in JSN at 2 years. While all allocation groups demonstrated reduced knee pain over the study period, none of the treatment allocation groups demonstrated significant symptomatic benefit above placebo.

TRIAL REGISTRATION CLINICALTRIALSGOV IDENTIFIER

NCT00513422; http://www.clinicaltrials.gov.

Nutraceuticals in the management of osteoarthritis : a critical review

Osteoarthritis (OA) is a chronic, highly prevalent and disabling disease that is expected to increase in prevalence secondary to longer life expectancy and a disproportionately aging population. Treatment of OA is only marginally effective and has been focused primarily on symptom control using weight loss, physical therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, intra-articular steroids or viscosupplementation, topical NSAIDs and analgesics, diacerein (an oral interleukin-1β inhibitor) and finally joint replacement surgery. The use of nutraceuticals in the treatment of OA is common, and scientific studies examining the effects of nutraceuticals on the pathogenesis and treatment of OA are increasing. This review examines the efficacy and safety of select nutraceuticals for the treatment of OA. The reviewed nutraceuticals include glucosamine, chondroitin, collagen hydrolysates (CHs) and avocado-soybean unsaponifiables (ASUs). There have been several clinical trials examining the efficacy of these products and the results demonstrate significant heterogeneity. Significant improvements in pain, function and structural outcomes have been shown for some of the treatment arms or subgroups of patients, but the effects are not consistent across the studies. Glucosamine, chondroitin and the two in combination have been the most extensively studied. Significant improvement in pain and functional indices and a decrease in the loss of joint space width were demonstrated in some but not all studies. CHs showed significant improvement in pain and functional indices for several subgroups of patients, but these findings were not pervasive amongst the treatment arms. ASU has demonstrated positive results with respect to decreased NSAID use in several studies and functional and pain end points in most of the reviewed studies; however, in the two studies examining structural end points, the results were mixed. The safety of these nutraceuticals has been demonstrated across all of the reviewed trials, and there were no significant issues with tolerance. Given the good safety profile of nutraceuticals, the marginal efficacy of conventional treatments, the high prevalence and rate of disability from OA and the possible benefit of nutraceuticals to patients with OA, use of nutraceuticals in select patients is appropriate. An overall recommendation to use nutraceuticals in the treatment of all patients with OA is not strongly supported by the available data. Future studies should focus on standardization of symptomatic and structural outcome measures, be of longer duration and pay careful attention to the content of the investigational product.

Chondroitin sulfate in the treatment of osteoarthritis: from in vitro studies to clinical recommendations

Chondroitin sulfate (CS) is recommended as a therapeutic intervention in the multimodal approach of osteoarthritis (OA) management. CS has been studied extensively to describe its pharmacology (pharmacokinetic, in vitro and in vivo effects) and its clinical efficacy. Various results have been reported depending on the system of evaluation (model, dosage and duration) and the source of CS (origin and quality). The purpose of this review was to gather most of the available information about CS and to discuss its potency in OA management.

Effects of Glucosamine and Chondroitin Sulfate on Cartilage Metabolism in OA: Outlook on Other Nutrient Partners Especially Omega-3 Fatty Acids

Osteoarthritis (OA) is a degenerative joint disease that is characterized by increasing loss of cartilage, remodeling of the periarticular bone, and inflammation of the synovial membrane. Besides the common OA therapy with nonsteroidal anti-inflammatory drugs (NSAIDs), the treatment with chondroprotectives, such as glucosamine sulfate, chondroitin sulfate, hyaluronic acid, collagen hydrolysate, or nutrients, such as antioxidants and omega-3 fatty acids is a promising therapeutic approach. Numerous clinical studies have demonstrated that the targeted administration of selected micronutrients leads to a more effective reduction of OA symptoms, with less adverse events. Their chondroprotective action can be explained by a dual mechanism: (1) as basic components of cartilage and synovial fluid, they stimulate the anabolic process of the cartilage metabolism; (2) their anti-inflammatory action can delay many inflammation-induced catabolic processes in the cartilage. These two mechanisms are able to slow the progression of cartilage destruction and may help to regenerate the joint structure, leading to reduced pain and increased mobility of the affected joint.

Nutraceuticals: do they represent a new era in the management of osteoarthritis? - a narrative review from the lessons taken with five products

OBJECTIVES

The aim of this first global systematic review on selected nutraceuticals was to synthesize and evaluate scientific relevant data available in the literature. Evidences that can support health, physiological or functional benefit on osteoarthritis (OA) were gathered and the level of evidence relative to each of these ingredients was highlighted.

METHODOLOGY

Relevant scientific data (positive or not) regarding OA were searched for five groups of compounds (avocado/soybean unsaponifiables (ASU), n-3 polyunsaturated fatty acids, collagen hydrosylates (CHs), vitamin D, polyphenols) within preclinical (in vitro and in vivo), epidemiological, and clinical studies. The following criteria were evaluated to assess the methodology quality of each study: (1) study question; (2) study population; (3) primary endpoint; (4) study design (randomization, control, blinding, duration of follow up); (5) data analysis and interpretation. A scientific consensus was determined for all studied nutraceuticals to evaluate their efficacy in OA.

RESULTS

The studied compounds demonstrated different potencies in preclinical studies. Most of them have demonstrated anti-catabolic and anti-inflammatory effects by various inhibitory activities on different mediators. Vitamin D showed a pro-catabolic effect in vitro and the polyphenol, Genistein, had only anti-inflammatory potency. The evaluation of the clinical data showed that ASU was the only one of the studied ingredients to present a good evidence of efficacy, but the efficient formulation was considered as a drug in some countries. Pycnogenol showed moderate evidence of efficacy, and vitamin D and collagen hydrolysate demonstrated a suggestive evidence of efficacy, whereas curcumin, epigallocatechin-3-gallate (EGCG) and resveratrol had only preclinical evidence of efficacy due to the lack of clinical data. The literature gathered for n-3 PUFA, nobiletin and genistein was insufficient to conclude for their efficacy in OA.

CONCLUSION

Additional data are needed for most of the studied nutraceuticals. Studies of good quality are needed to draw solid conclusions regarding their efficacy but nutraceuticals could represent good alternates for OA management. Their use should be driven by any recommendations.

Modern management of mild-to-moderate joint pain due to osteoarthritis: a holistic approach

Osteoarthritis (OA) is the most common form of arthritis and it is often associated with significant disability and impaired quality of life. Once thought to be caused by an age-related 'wearing out' of articular cartilage, it is now recognized to be a dynamic process in which cartilage degradation alternates with repair. Several expert guidelines for the management of OA exist, which concur in their recommendations for a stepwise approach to the employment of pharmacological agents and the introduction of suggestions to extend the use of agents such as topical non-steroidal anti-inflammatory drugs, especially for mild-to-moderate forms of the disease. They also emphasize the importance of non-pharmacological measures, such as nutraceuticals, education, diet, exercise and the use of aids in improving signs and symptoms and slowing progression. In many countries, effective medicinal and nutraceutical agents are available 'over-the-counter'. This review explains the modern approach to the management of mild-to-moderate osteoarthritic pain.

Immune modulation by chondroitin sulfate and its degraded disaccharide product in the development of an experimental model of multiple sclerosis

Clinical symptoms in MOG-induced EAE mice significantly exacerbated following chondroitin sulfate A (CS-A) injection, whereas administration of a degraded product, CSPG-DS, caused dramatic inhibition of EAE development. Also, administration of CSPG-DS but not CS-A, after the onset of clinical symptoms of EAE, was able to suppress the disease. Further studies demonstrated that CS-A up-regulated STAT4 expression and thus, induced IFN-gamma production and Th1 CD4 T cell differentiation. CS-A also up-regulated STAT3 and IL-23 expression and thus increased IL-17 producing T cells. CSPG-DS treatment both in vivo and in vitro decreased TNFalpha production from splenocytes. In vitro and in vivo studies indicated that CSPG-DS treatment in EAE mice significantly blocked migration of lymphocytes, whereas CS-A treatment increased lymphocyte infiltration in the brain.

Antioxidant, antiinflammatory and neuroprotective actions of chondroitin sulfate and proteoglycans

The antiinflammatory and antiapoptotic effects of chondroitin sulfate (CS) are being used to treat osteoarthritis. Recent evidence has revealed that those peripheral effects of CS may also have therapeutic interest in diseases of the central nervous system (CNS). We review here such evidence. Perineuronal nets (PNNs) formed by chondroitin sulfate proteoglycans (CSPGs) may have a neuroprotective action against oxidative stress potentially involved in neurodegeneration. On the other hand, in human neuroblastoma SH-SY5Y cells CS has antioxidant and neuroprotective effects by activating the signaling pathway PKC/PI3K/Akt and inducing the antioxidant enzyme hemoxygenase-1. Consistent with this is the observation that protein kinase C (PKC) blockade overcomes inhibition of neurite outgrowth elicited by CSPGs. In addition, CS protects cortical neurons against excytotoxic death by phosphorylation of intracellular signals and the suppression of caspase-3 activation. Of interest is the finding that a disaccharide derived from CSPG degradation (CSGP-DS) protects neurons against toxicity both in vitro and in vivo. Furthermore, CSGP-DS efficiently protects against neuronal loss in experimental autoimmune encephalomyelitis and uveitis, decreases secretion of tumor necrosis factor-alpha (TNF-alpha) and block necrosis factor kappa B (NF-kappaB) translocation. In conclusion, CS may have neuroprotective properties linked to its antioxidant and antiinflammatory effects.

Quality of different chondroitin sulfate preparations in relation to their therapeutic activity

Objectives

Chondroitin sulfate is currently recommended by the European League Against Rheumatism (EULAR) as a SYSADOA (symptomatic slow acting drug for osteoarthritis) in Europe in the treatment of knee and hand osteoarthritis based on research evidence and meta-analysis of numerous clinical studies. Furthermore, recent clinical trials demonstrated its possible structure-modifying effects. Chondroitin sulfate, alone or in combination with glucosamine or other ingredients, is also utilized as a nutraceutical in dietary supplements in Europe and the USA. However, it is derived from animal sources by extraction and purification processes. As a consequence, source material, manufacturing processes, the presence of contaminants and many other factors contribute to the overall biological and pharmacological actions of these agents. We aim to review the quality control of chondroitin sulfate in pharmaceutical-grade preparations and nutraceuticals.

Key findings

Pharmaceutical-grade formulations of chondroitin sulfate are of high and standardized quality, purity and properties, due to the stricter regulations to which this drug is subjected by local national health institutes as regards production and characteristics. On the contrary, as several published studies available in literature indicate, the chondroitin sulfate quality of several nutraceuticals is poor. Additionally, there are no definite regulations governing the origin of the ingredients in these nutraceuticals and the origin of the ingredients in natural products is the most important factor ensuring quality, and thus safety and efficacy, in particular for chondroitin sulfate, due to its extraction from different sources.

Conclusions

Due to the poor chondroitin sulfate quality of some nutraceuticals, we conclude that stricter regulations regarding their quality control should be introduced to guarantee the manufacture of high quality products for nutraceutical utilization and to protect customers from low-quality, ineffective and potentially dangerous products. There is a need for specific and accurate analytical procedures, which should be enforced to confirm purity and label claims both for raw materials and finished chondroitin sulfate products, and also to govern the origin of ingredients. Until these stricter regulations are in place, then it is strongly recommended that pharmaceutical-grade chondroitin sulfate is used rather than food supplements.

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.