Dietary supplements for treating osteoarthritis: a systematic review and meta-analysis

The Relationship between Vitamin K and Osteoarthritis: A Review of Current Evidence

Vitamin K is a cofactor of γ-glutamyl carboxylase, which plays an important role in the activation of γ-carboxyglutamate (gla)-containing proteins that negatively regulate calcification. Thus, vitamin K status might be associated with osteoarthritis (OA), in which cartilage calcification plays a role in the pathogenesis of the disease. This review collates the evidence on the relationship between vitamin K status (circulating or dietary intake level of vitamin K, or circulating uncarboxylated gla proteins) and OA from human observational studies and clinical trial, to examine its potential as an agent in preventing OA. The current literature generally agrees that a sufficient level of vitamin K is associated with a lower risk of OA and pathological joint features. However, evidence from clinical trials is limited. Mechanistic study shows that vitamin K activates matrix gla proteins that inhibit bone morphogenetic protein-mediated cartilage calcification. Gla-rich proteins also inhibit inflammatory cascade in monocytic cell lines, but this function might be independent of vitamin K-carboxylation. Although the current data are insufficient to establish the optimal dose of vitamin K to prevent OA, ensuring sufficient dietary intake seems to protect the elderly from OA.

Undenatured Type II Collagen (UC-II) in Joint Health and Disease: A Review on the Current Knowledge of Companion Animals

OA is quite common in companion animals, especially in large breed dogs and horses. Collagen, the most abundant protein of mammals, has specific connective tissue types for skin, bones, reticulate, basal lamina, bones, cell surfaces, while type II collagen (UC-II) forms the main structure of cartilage tissue. Even at the smaller dosages, UC-II has also been reported to be more effective than the glucosamine and chondroitin sulfate supplements, which are the supplements most frequently used in the market. In this review, we summarize the effects of UC-II on joint health and function in health and disease conditions in companion animals.

Efficacy and safety of a supplement combination for hand osteoarthritis pain: protocol for an internet-based randomised placebo-controlled trial (The RADIANT study)

INTRODUCTION

Hand osteoarthritis (HOA) is a highly prevalent disabling joint disease. The current management regimens are limited. Potentially as a consequence, many people turn to complementary and alternative medicines for symptomatic relief. A combination of two or more supplements is common in clinical practice; however, evidence for the efficacy of this approach is lacking. The aim of this study is to investigate the efficacy of a supplement combination for treating symptomatic HOA in comparison to placebo.

METHODS AND ANALYSIS

The RADIANT study is an internet-based, parallel, superiority, double-blind, placebo-controlled, randomised, two-arm clinical trial. A participatory design is used to facilitate the study procedures. One hundred and six participants aged over 40 years with painful HOA and structural change on X-ray (Kellgren and Lawrence grade (KLG) ≥2) will be recruited from the community and randomly allocated to receive either a supplement combination composed of: (1) combined supplement containing Boswellia serrata extract, pine bark extract and methylsulfonylmethane and (2) curcumin or placebo for 12 weeks. The primary outcome will be 12-week change in hand pain on a visual analogue scale (VAS). Main secondary outcomes include adverse events, change in hand function, patient global assessment of disease activity and quality of life. A range of additional measures will be recorded, and an individual patient placebo response will be performed. The primary analysis will be conducted using an intention-to-treat approach. Adverse events will be monitored weekly throughout the study.

ETHICS AND DISSEMINATION

This protocol has been approved by the University of Sydney Human Research Ethics Committee (HREC No. 2018/766). Dissemination will occur through conferences, social media, scientific publications and PhD thesis.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12619000835145); Pre-results.

[Symptomatic slow-acting drugs in the treatment of osteoarthritis: focus on glucosamine preparations]

The article discusses the place of symptomatic slow-acting drugs in current guidelines for the treatment of osteoarthritis. Special emphasis is put ot glucosamine preparations, the attitude towards which, until recently, was ambiguous. The results of experimental and clinical studies demonstrating the advantages of crystalline glucosamine sulfate over preparations/food additives of glucosamine hydrochloride are presented. The differences in the pharmacodynamics and pharmacokinetics of glucosamine sulfate and glucosamine hydrochloride, which may be the reason for the ineffectiveness of the latter in clinical trials, are discussed.

Comparison of the Clinical Effectiveness of Single Versus Multiple Injections of Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review and Meta-analysis

Background

Reports have concluded that platelet-rich plasma (PRP) is an effective and safe biological approach in the treatment of knee osteoarthritis (OA). However, no consensus has been established regarding the number of injections required to observe a therapeutic effect.

Purpose

To compare the clinical effectiveness reported in randomized controlled trials (RCTs) of single versus multiple PRP injections in the treatment of knee OA.

Study Design

Systematic review; Level of evidence, 1.

Methods

A comprehensive search was conducted for RCTs published between 1970 and 2019 that compared the effect of single versus multiple PRP injections on pain and functionality in patients with knee OA. Searched databases included MEDLINE, Scopus, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. A data extraction form was designed to obtain bibliographic information of the study as well as patient, intervention, comparison, and outcomes of interest data. A random-effects model was used to pool quantitative data from the primary outcomes.

Results

We included 5 clinical trials with a low-moderate risk of bias that reported data for 301 patients. Meta-analysis showed that, at 6 months after the intervention, single and multiple (double or triple) injections had similar pain improvement, with no significant differences (standardized mean difference [SMD], 0.61 [95% CI, -1.09 to 2.31]; I ² = 97%; P = .48). A significant improvement in knee functionality was observed in favor of multiple injections (SMD, 2.29 [95% CI, 0.45-4.12]; I ² = 97%; P = .01). Subanalysis showed that the significant improvement was only evident for the results of single versus triple injections (SMD, 3.12 [95% CI, 0.64-5.60]; I ² = 97%; P = .01).

Conclusion

According to our results, a single injection was as effective as multiple PRP injections in pain improvement; however, multiple injections seemed more effective in joint functionality than a single injection at 6 months. We consider that the available evidence is still insufficient, and future research on this specific topic is needed to confirm our results.

Multifaceted Protective Role of Glucosamine against Osteoarthritis: Review of Its Molecular Mechanisms

Osteoarthritis (OA) is a joint disease resulting from cartilage degeneration and causing joint pain and stiffness. Glucosamine exerts chondroprotective effects and effectively reduces OA pain and stiffness. This review aims to summarise the mechanism of glucosamine in protecting joint health and preventing OA by conducting a literature search on original articles. Current evidence has revealed that glucosamine exhibits anti-inflammatory effects by reducing the levels of pro-inflammatory factors (such as tumour necrosis factor-alpha, interleukin-1, and interleukin-6) and enhancing the synthesis of proteoglycans that retard cartilage degradation and improve joint function. Additionally, glucosamine improves cellular redox status, reduces OA-mediated oxidative damages, scavenges free radicals, upregulates antioxidant proteins and enzyme levels, inhibits the production of reactive oxygen species, and induces autophagy to delay OA pathogenesis. In conclusion, glucosamine prevents OA and maintains joint health by reducing inflammation, improving the redox status, and inducing autophagy in joints. Further studies are warranted to determine the synergistic effect of glucosamine with other anti-inflammatory and/or antioxidative agents on joint health in humans.

Pharmacokinetic assessment of constituents of Boswellia serrata, pine bark extracts, curcumin in combination including methylsulfonylmethane in healthy volunteers

OBJECTIVES

Dietary supplements are increasingly used by people with osteoarthritis. Boswellia serrata extract, curcumin, pine bark extract and methylsulfonylmethane have been identified as having the largest effects for symptomatic relief in a systematic review. It is important to understand whether any pharmacokinetic interactions are among the major constituents of these supplements so as to provide information when considering the combination use of these supplements. The aim of this study was to investigate the pharmacokinetics of the constituents alone and in combination.

METHODS

This study was a randomized, open-label, single-dose, four-treatment, four-period, crossover study with 1-week washout. The pharmacokinetics of the constituents of these supplements when dosed in combination with methylsulfonylmethane were compared to being administered alone. Plasma samples were obtained over 24 h from 16 healthy participants. Eight major constituents were analysed using a validated ultra-high-performance liquid chromatography-tandem mass spectrometry assay.

KEY FINDINGS

The pharmacokinetics of each constituent was characterized, and there were no significant differences in the pharmacokinetic profiles of the constituents when administered as a combination, relative to the constituents when administered alone (P > 0.05).

CONCLUSIONS

These data suggest that interactions between the major constituents of this supplement combination are unlikely and therefore could be investigated to manage patients with osteoarthritis without significant concerns for possible pharmacokinetic interactions.

Effects of Extract of Arrabidaea chica Verlot on an Experimental Model of Osteoarthritis

The aim of this study was to analyze the analgesic potential of Arrabidaea chica extract (EHA) as an alternative to osteoarthritis (OA) treatment. Thus, the extract was initially evaluated by the cyclooxygenase inhibition test. The analgesic effect of the extract, in vivo, was also verified in a model of OA induced by sodium monoiodoacetate (2 mg). EHA was administered to rats at doses of 50, 150, and 450 mg/kg between 3 and 25 days after OA induction. The animals were clinically evaluated every 7 days, euthanized at 29 days, and the liver, spleen, kidney and knee collected for histopathological analysis. The chemical composition of EHA was identified by HPLC-MS and the identified compounds submitted to molecular docking study. The results showed that the extract promoted cyclooxygenase inhibition and produced significant improvements in disability, motor activity, hyperalgesia, and OA-induced allodynia parameters, in addition to improvements in the radiological condition of the knees (but not observed in the histopathological study). Chemically the extract is rich in flavonoids. Among them, we evidence that amentoflavone showed very favorable interactions with the enzyme COX-2 in the in silico analysis. Thus, it is concluded that A. chica has important analgesic properties for the treatment of OA.

Computational Assessment of the Pharmacological Profiles of Degradation Products of Chitosan

Chitosan is a natural polymer revealing an increased potential to be used in different biomedical applications, including drug delivery systems, and tissue engineering. It implies the evaluation of the organism response to the biomaterial implantation. Low-molecular degradation products, the chito-oligomers, are resulting mainly from the influence of enzymes, which are found in the organism fluids. Within this study, we have performed the computational assessment of pharmacological profiles and toxicological effects on human health of small chito-oligomers with distinct molecular weights, deacetylation degrees, and acetylation patterns. Our approach is based on the fact that regulatory agencies and researchers in the drug development field rely on the use of modeling to predict biological effects and to guide decision making. To be considered as valid for regulatory purposes, every model that is used for predictions should be associated with a defined toxicological endpoint and has appropriate robustness and predictivity. Within this context, we have used FAF-Drugs4, SwissADME, and PreADMET tools to predict the oral bioavailability of chito-oligomers and SwissADME, PreADMET, and admetSAR2.0 tools to predict their pharmacokinetic profiles. The organs and genomic toxicities have been assessed using admetSAR2.0 and PreADMET tools but specific computational facilities have been also used for predicting different toxicological endpoints: Pred-Skin for skin sensitization, CarcinoPred-EL for carcinogenicity, Pred-hERG for cardiotoxicity, ENDOCRINE DISRUPTOME for endocrine disruption potential and Toxtree for carcinogenicity and mutagenicity. Our computational assessment showed that investigated chito-oligomers reflect promising pharmacological profiles and limited toxicological effects on humans, regardless of molecular weight, deacetylation degree, and acetylation pattern. According to our results, there is a possible inhibition of the organic anion transporting peptides OATP1B1 and/or OATP1B3, a weak potential of cardiotoxicity, a minor probability of affecting the androgen receptor, and phospholipidosis. Consequently, these results may be used to guide or to complement the existing in vitro and in vivo toxicity tests, to optimize biomaterials properties and to contribute to the selection of prototypes for nanocarriers.

The Effects of Annatto Tocotrienol Supplementation on Cartilage and Subchondral Bone in an Animal Model of Osteoarthritis Induced by Monosodium Iodoacetate

Osteoarthritis is a degenerative joint disease which primarily affects the articular cartilage and subchondral bones. Since there is an underlying localized inflammatory component in the pathogenesis of osteoarthritis, compounds like tocotrienol with anti-inflammatory properties may be able to retard its progression. This study aimed to determine the effects of oral tocotrienol supplementation on the articular cartilage and subchondral bone in a rat model of osteoarthritis induced by monosodium iodoacetate (MIA). Thirty male Sprague-Dawley rats (three-month-old) were randomized into five groups. Four groups were induced with osteoarthritis (single injection of MIA at week 0) and another served as the sham group. Three of the four groups with osteoarthritis were supplemented with annatto tocotrienol at 50, 100 and 150 mg/kg/day orally for five weeks. At week 5, all rats were sacrificed, and their tibial-femoral joints were harvested for analysis. The results indicated that the groups which received annatto tocotrienol at 100 and 150 mg/kg/day had lower histological scores and cartilage remodeling markers. Annatto tocotrienol at 150 mg/kg/day significantly lowered the osteocalcin levels and osteoclast surface of subchondral bone. In conclusion, annatto tocotrienol may potentially retard the progression of osteoarthritis. Future studies to confirm its mechanism of joint protection should be performed.

Bio-optimized Curcuma longa extract is efficient on knee osteoarthritis pain: a double-blind multicenter randomized placebo controlled three-arm study

Objectives

Comparison of two doses of bio-optimized Curcuma longa extract (BCL) in the management of symptomatic knee osteoarthritis (OA).

Methods

A prospective, randomized, 3-month, double-blind, multicenter, three-group, placebo-controlled trial assessing Patient Global Assessment of Disease Activity (PGADA) and serum sColl2-1, a biomarker of cartilage degradation, as co-primary endpoints. Pain on visual analog scale (VAS), Knee injury and Osteoarthritis Outcome Score (KOOS), and paracetamol/non-steroidal anti-inflammatory drug (NSAID) consumption were used as secondary endpoints.

Results

One hundred fifty patients with knee OA were followed for 90 days. Low and high doses of BCL showed a greater decrease of PGADA than placebo. Analysis of sColl2-1 showed in the placebo and BCL low-dose groups, but not in the BCL high-dose group, a transient but non-significant increase of sColl2-1 between T0 and T1. Thereafter, in all groups, sColl2-1 decreased between T1 and T3 (all p < 0.01), but no difference between the groups was found. Pain reduction at day 90 in the low- and high-dose BCL groups (− 29.5 mm and − 36.5 mm) was higher than that in the placebo (− 8 mm; p = 0.018). The global KOOS significantly decreased overtime, but changes were comparable across treatment arms. The ratio of patients with adverse events (AE) related to the product was similar in the placebo and treatment groups, but the number of AE linked to the product was higher in the high-dose BCL group compared to the placebo (p = 0.012).

Conclusions

BCL appeared safe and well-tolerated with no evidence of severe adverse effects. Efficacy analysis suggested positive trends for measurements of PGADA and serum levels of an OA biomarker and showed a rapid and significant decrease of pain in knee OA (Trial registration: ISRCTN, ISRCTN12345678. Registered 21 September 2016—retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02909621?term=osteoarthritis+curcumin&rank=5—Evaluation of FLEXOFYTOL® Versus PLACEBO (COPRA) NCT02909621).

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1960-5) contains supplementary material, which is available to authorized users.

Efficacy and safety of avocado-soybean unsaponifiables for the treatment of hip and knee osteoarthritis: A systematic review and meta-analysis of randomized placebo-controlled trials

OBJECTIVE

We performed a systematic review and meta-analysis from randomized controlled trials to examine the efficacy and safety of avocado-soybean unsaponifiables (ASU) in patients with hip or knee osteoarthritis (OA).

DATA SOURCES

Medline, SCOPUS, Web of Science, and Google Scholar databases were searched for randomized placebo-controlled trials.

STUDY SELECTION

Original studies were randomized placebo-controlled trials evaluating the effect of orally administered ASU on knee or hip OA symptoms using the Lequesne index, visual analog scale (VAS) and/or joint space width (JSW).

DATA EXTRACTION

Meta-analysis was conducted using a random-effects model and generic inverse variance method. Heterogeneity was tested using the I² statistic index.

DATA SYNTHESIS

Avocado-soybean unsaponifiables therapy had a significant reduction on pain by VAS assessment (weighted mean difference [WMD]: -9.64 mm, 95% CI: -17.43, -1.84; P = .02; I²  = 92%). A subanalysis according to the type of OA showed that ASU significantly decreased both VAS and Lequesne index in knee OA (WMD: -17.36, 95% CI: -25.91, -8.82; P < .0001; I²  = 87% and WMD: -2.33, 95% CI: -2.88, -1.78; P < .00001; I²  = 18%, respectively) but not in hip OA. Finally, ASU supplementation showed no significant differences for adverse events compared to placebo (relative risk: 1.02, 95% CI: 0.83, 1.25; P = .88; I²  = 0%).

CONCLUSION

Results of this meta-analysis suggest a beneficial effect of ASU treatment in symptomatic knee OA but not in hip OA. Additionally, adverse events were similar in patients receiving ASU therapy or placebo.

Glucosamine promotes hepatitis B virus replication through its dual effects in suppressing autophagic degradation and inhibiting MTORC1 signaling

Glucosamine (GlcN), a dietary supplement widely utilized to promote joint health and effective in the treatment of osteoarthritis, is an effective macroautophagy/autophagy activator in vitro and in vivo. Previous studies have shown that autophagy is required for hepatitis B virus (HBV) replication and envelopment. The objective of this study was to determine whether and how GlcN affects HBV replication, using in vitro and in vivo experiments. Our data demonstrated that HBsAg production and HBV replication were significantly increased by GlcN treatment. Confocal microscopy and western blot analysis showed that the amount of autophagosomes and the levels of autophagic markers MAP1LC3/LC3-II and SQSTM1 were clearly elevated by GlcN treatment. GlcN strongly blocked autophagic degradation of HBV virions and proteins by inhibiting lysosomal acidification through its amino group. Moreover, GlcN further promoted HBV replication by inducing autophagosome formation via feedback inhibition of mechanistic target of rapamycin kinase complex 1 (MTORC1) signaling in an RRAGA (Ras related GTP binding A) GTPase-dependent manner. In vivo, GlcN application promoted HBV replication and blocked autophagic degradation in an HBV hydrodynamic injection mouse model. In addition, GlcN promoted influenza A virus, enterovirus 71, and vesicular stomatitis virus replication in vitro. In conclusion, GlcN efficiently promotes virus replication by inducing autophagic stress through its dual effects in suppressing autophagic degradation and inhibiting MTORC1 signaling. Thus, there is a potential risk of enhanced viral replication by oral GlcN intake in chronically virally infected patients.Abbreviations: ACTB: actin beta; ATG: autophagy-related; CMIA: chemiluminescence immunoassay; ConA: concanavalin A; CQ: chloroquine; CTSD: cathepsin D; DAPI: 4',6-diamidino-2-phenylindole; EV71: enterovirus 71; GalN: galactosamine; GFP: green fluorescence protein; GlcN: glucosamine; GNPNAT1: glucosamine-phosphate N-acetyltransferase 1; HBP: hexosamine biosynthesis pathway; HBV: hepatitis B virus; HBcAg: hepatitis B core antigen; HBsAg: hepatitis B surface antigen; HBeAg: hepatitis B e antigen; HBV RI: hepatitis B replicative intermediate; IAV: influenza A virus; LAMP1: lysosomal associated membrane protein 1; LAMTOR: late endosomal/lysosomal adaptor, MAPK and MTOR activator; ManN: mannosamine; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTORC1: mechanistic target of rapamycin kinase complex 1; PHH: primary human hepatocyte; RAB7: RAB7A, member RAS oncogene family; RPS6KB1: ribosomal protein S6 kinase B1; RRAGA: Ras related GTP binding A; RT-PCR: reverse transcriptase polymerase chain reaction; SEM: standard error of the mean; siRNA: small interfering RNA; SQSTM1/p62: sequestosome 1; UAP1: UDP-N-acetylglucosamine pyrophosphorylase 1; VSV: vesicular stomatitis virus.

Human Enriched Serum Following Hydrolysed Collagen Absorption Modulates Bone Cell Activity: from Bedside to Bench and Vice Versa

Collagen proteins are crucial components of the bone matrix. Since collagen-derived products are widely used in the food and supplement industry, one may raise the question whether collagen-enriched diets can provide benefits for the skeleton. In this study, we designed an innovative approach to investigate this question taking into account the metabolites that are formed by the digestive tract and appear in the circulation after ingestion of hydrolysed collagen. Blood samples collected in clinical and pre-clinical trials following ingestion and absorption of hydrolysed collagen were processed and applied on bone-related primary cell cultures. This original ex vivo methodology revealed that hydrolysed collagen-enriched serum had a direct impact on the behaviour of cells from both human and mouse origin that was not observed with controls (bovine serum albumin or hydrolysed casein-enriched serum). These ex vivo findings were fully in line with in vivo results obtained from a mouse model of post-menopausal osteoporosis. A significant reduction of bone loss was observed in mice supplemented with hydrolysed collagen compared to a control protein. Both the modulation of osteoblast and osteoclast activity observed upon incubation with human or mouse serum ex vivo and the attenuation of bone loss in vivo, clearly indicates that the benefits of hydrolysed collagen for osteoporosis prevention go beyond the effect of a simple protein supplementation.

Enzymatic Hydrolysis of a Collagen Hydrolysate Enhances Postprandial Absorption Rate-A Randomized Controlled Trial

Collagen is characterized by its high content of glycine, proline and hydroxyproline, and is found to exert beneficial effects on joint pain related to activity and osteoarthritis. However, to exert any beneficial effects it is essential that collagen is optimally absorbed. This study aimed to investigate the postprandial absorption of collagen and elucidate the impact of an exogenous enzymatic hydrolysis on absorption rate and bioavailability. A randomized, blinded, cross-over study was conducted where ten healthy male subjects received either 35 g enzymatically hydrolyzed collagen protein (EHC), 35 g non-enzymatically hydrolyzed collagen protein (NC) or placebo (250 mL water) on three nonconsecutive days. Blood samples were drawn before, and up to 240 min following, ingestion and the blood metabolome was characterized by nuclear magnetic resonance (NMR)-based metabolomics. A significant increase in the plasma concentration of nearly all amino acids (AAs) was observed over a 240 min period for both EHC and NC. In addition, the absorption rate and bioavailability of glycine, proline and hydroxyproline were significantly higher for EHC (p < 0.05). In conclusion, ingestion of collagen hydrolysates increases postprandial plasma concentrations of AAs over a period of 240 min, and an enzymatic hydrolysis increases the absorption rate and bioavailability of the collagen-rich AAs glycine, proline and hydroxyproline.

A double-blind, randomized, placebo-controlled study to assess the efficacy of Andrographis paniculata standardized extract (ParActin®) on pain reduction in subjects with knee osteoarthritis

Andrographis paniculata Wall (Acanthaceae) is becoming more recognized for its anti-inflammatory and antioxidant properties. A randomized, double-blind, placebo-controlled study was conducted to assess the efficacy of an andrographolide-containing supplement, ParActin® (300 and 600 mg daily), on Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain reduction in patients with knee osteoarthritis. Joint stiffness, physical function, changes in the SF-36 quality of life questionnaire, a fatigue scale, and safety were also evaluated. A total of 103 male and female patients with I-II osteoarthritis of the knee joint were assessed. Patients treated with 300 or 600 mg/day of ParActin® showed a significant reduction in pain at days 28, 56, and 84 compared with a placebo group. WOMAC stiffness scores, physical function score, and the fatigue score showed a significant improvement in both ParActin®-treated groups compared with the placebo group. At the end of the study, the quality of life (SF-36 questionnaire) and Functional Assessment of Chronic Illness Therapy (FACIT) scores showed significant improvements in both ParActin®-treated groups compared with the placebo group. Overall, it can be concluded that ParActin® in 300 and 600 mg/day dosages were found to be effective and safe in reducing pain in individuals suffering from mild to moderate knee osteoarthritis.

A systematic review of osteoarthritis prevention and management with dietary phytochemicals from foods

Osteoarthritis is the most prevalent chronic inflammatory joint disease affecting mobility in humans, as well as in companion and captive animals. Understanding the effect of dietary phytochemical intake from foods on osteoarthritis and its long-term outcomes may inform public health strategies for osteoarthritis prevention and management, reducing healthcare costs globally. The aim of this systematic review was to examine the effects of dietary phytochemical intake from foods on osteoarthritis in adult populations. A literature search was performed using Scopus, Web of Science, MEDLINE, PubMed and the Cochrane Library for human studies to identify randomised controlled trials (RCTs) and observational studies focused on osteoarthritis up to May 2018. From 5879 articles, five RCTs and four cross-sectional studies were identified. Dietary carotenoids were examined in the observational studies, while dietary intakes of polyphenols from foods were assessed in the RCTs. Dietary polyphenol intake from foods (e.g., freeze-dried strawberries and tart cherry juice) may slow the progression of osteoarthritis via decreased inflammation and reduced cartilage degradation. However, there were relatively few studies and a lack of uniformity in the biomarkers used and the measurements of pain, quality of life and physical activity relating to osteoarthritis. The heterogeneity among the studies suggests that there is insufficient evidence related to phytochemical intake from foods. High-quality epidemiological studies and controlled trials are therefore required. Nevertheless, exploring dietary phytochemical intake from foods may complement current dietary strategies for the management of osteoarthritis and help in the formulation of more economical and manageable strategies for osteoarthritis.

Predictive factors of adherence to an association of glucosamine sulfate, copper, and ginger extracts in patients with symptomatic osteoarthritis: a prospective open-label French noninterventional study (the PREDOA study)

Background: Osteoarthritis (OA) management needs a combination of nonpharmacological and pharmacological modalities. However, as in many chronic conditions, the main concern with OA therapy is the difficulty in obtaining good medication compliance over a long period. The PREDOA study aimed to investigate the predictive factors of adherence to treatment in patients with OA treated with glucosamine sulfate (GS)-copper sulfate-ginger root (GCu), a symptomatic slow-acting drug for OA. Methods: Ambulatory patients with a clinical diagnosis of OA were included in a prospective (6 months) multicenter open-label observational study. All patients received two capsules of GS-GCu once daily for 6 months. Demographics, disease features (OA location, symptom duration, concomitant therapies, comorbidities), and patient self-assessment of pain (0-10) were obtained at baseline. At month 6, the investigator collected patient self-assessments of treatment observance, reasons for nonadherence, pain scores, patient perceptions of treatment efficacy, changes in analgesic intake, and occurrence of adverse events. Predictors of observance were studied in univariate and multivariate analyses. Results: A total of 2,030 patients were included in the study. At baseline, the average pain score was 6.4±1.7. Observance was good in 80% of patients. It was weaker in active than retired patients (P=0.005) in patients not taking concomitant treatment (P=0.008) or who had never been treated for OA (P=0.001). Observance was correlated with pain decrease (P<0.0001) and with lack of adverse effects (P<0.001). Age, sex, pain level at baseline, OA location, and number of painful joints were not related to treatment compliance. Conclusion: Medication compliance with GS-GCu depends both on the safety-efficacy balance and several patient related-factors. To improve adherence, detailed information about therapeutic objectives is necessary in active patients who do not get any other medications and for whom it is their first treatment for OA. Clinical trial identifier: CCTIRS 14-371 B.

A Curcumin Degradation Product, 7-Norcyclopentadione, Formed by Aryl Migration and Loss of a Carbon from the Heptadienedione Chain

Evidence that anti-inflammatory and other biological effects of curcumin may at least in part be mediated by its metabolites underscores the importance of identifying novel transformation products. Spontaneous degradation of curcumin in buffer pH 7.5 results mainly in dioxygenated products with a characteristic cyclopentadione ring composed of carbons 2 through 6 of the former heptadienedione chain. When analyzing degradation reactions of 4'- O-methylcurcumin, a product was identified missing one of the terminal carbons of the heptadienedione moiety while containing a cyclopentadione ring and adjacent hydroxy group typical of curcumin degradation products. Analysis of curcumin autoxidation reactions showed formation of an analogous compound, 7-norcyclopentadione, a degradation product exhibiting net loss of a carbon and gain of an oxygen atom. Removal of the carbon is proposed to occur via a peroxide-linked curcumin dimer in conjunction with radical-mediated 1,2-aryl migration of a guaiacol moiety. Oxidation reactions of demethoxycurcumin gave demethoxy-7-norcyclopentadione, whereas an analogous product was not observed from bis-demethoxycurcumin. Incubation of RAW264.7 macrophage-like cells with curcumin showed the presence of 7-norcyclopentadione, the formation of which was not increased upon activation of the cells with 12- O-tetradecanoylphorbol-13-acetate . 7-Norcyclopentadione is a novel type of degradation product that is most likely formed via autoxidative processes when cells are incubated with curcumin.

Natural Products for Promoting Joint Health and Managing Osteoarthritis

PURPOSE OF REVIEW

Osteoarthritis, the most common joint disease, is associated with substantial medical costs, lost productivity, and reduced quality of life. However, available pharmaceutical treatments have limitations in terms of efficacy and long-term safety.

RECENT FINDINGS

In vitro evidence suggests that some natural products may possess anti-inflammatory and anti-oxidative properties and may inhibit the release of key osteoarthritis-related cytokines. There is, therefore, ongoing interest in identifying natural products that safely promote joint health and treat osteoarthritis. Numerous plant extracts, including curcumin, Boswellia extract, and pycnogenol, have shown effect sizes (ES) for reducing pain and functional disability larger than those observed with analgesics and products such as glucosamine and chondroitin. The ES for methylsulfonylmethane and avocado/soybean unsaponifiables are also considered to be clinically relevant. Data from a small number of studies using natural products for treating osteoarthritis are promising but require confirmation in further well-designed clinical trials.

Efficacy and safety of co-administration of resveratrol with meloxicam in patients with knee osteoarthritis: a pilot interventional study

Background and aim

Resveratrol shows remarkable anti-inflammatory activities in experimental models. This study aims to evaluate the effect of resveratrol, as an adjuvant with meloxicam (Mlx), on the pain and functional activity during a 90-day period and monitor the adverse effects on kidney and liver functions, lipid profile, and hematological markers.

Patients and methods

This study was a double-blind, placebo-controlled, randomized multi-center study that involved 110 patients with knee osteoarthritis (OA) and was performed at Sulaimani City, Iraq, from December 2016 to September 2017. To assess the effects of Mlx with or without resveratrol, pain severity and functional disability were evaluated at baseline and after 90 days using the Western Ontario and McMaster Universities Osteoarthritis Index. Fasting blood was collected to evaluate the lipid profile markers, hematological picture, and liver and kidney functions, in addition to vitamin D level.

Results

Resveratrol significantly improves pain, functions, and associated symptoms compared with placebo. The clinical and biochemical markers indicated that 500 mg/day of resveratrol, as an adjuvant with Mlx, is safe and well tolerated by the knee OA patients.

Conclusion

Resveratrol, as an “add-on” medication with Mlx, was superior in terms of safety and efficacy to Mlx alone for the treatment of pain and improvement of physical function in patients with knee OA.

Effect of glucosamine and chondroitin sulfate in symptomatic knee osteoarthritis: a systematic review and meta-analysis of randomized placebo-controlled trials

Although glucosamine and chondroitin sulfate have showed beneficial effects on joint tissues in osteoarthritis (OA), their therapeutic use in the clinical setting is still debatable. Hence, a systematic review and meta-analysis of randomized placebo-controlled trials was conducted to investigate the efficacy of glucosamine and chondroitin sulfate on knee OA symptoms. Medline, SCOPUS, Web of Science, and Google Scholar databases were searched for randomized placebo-controlled trials evaluating the effect of orally administered glucosamine and/or chondroitin sulfate on OA symptoms using the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) and/or the Visual Analog Scale (VAS). Meta-analysis was conducted using a random-effects model and generic inverse-variance method. Heterogeneity was tested using the I2 statistic index. Treatments with glucosamine and chondroitin were found to significantly reduce pain in VAS [weighted mean difference (WMD) - 7.41 mm, 95% CI - 14.31, - 0.51, p = 0.04 and WMD - 8.35 mm, 95% CI - 11.84, - 4.85, p < 0.00001, respectively]. Their combination did not show this behavior (WMD - 0.28 mm, 95% CI - 8.87, 8.32, p = 0.95). None of the glucosamine, chondroitin or their combination had a significant positive effect on the total WOMAC index and its subscores. Oral supplementation with glucosamine or chondroitin sulfate reduces pain in knee OA. However, there is no additional effect using both therapeutic agents in combination for the management of symptomatic knee OA.

Which supplements can I recommend to my osteoarthritis patients?

OA is a chronic and disabling joint disease with limited evidence-based pharmacological treatment options available that improve outcomes for patients safely. Faced with few effective pharmacological treatments, the use has grown of dietary supplements and complementary medicines for symptomatic relief among people living with OA. The aim of this review is to provide a summary of existing evidence and recommendations supporting the use of supplements for OA. Systematic reviews and randomized controlled trials investigating oral supplements for treating OA were identified. Limited research evidence supports recommendations for the oral use of Boswellia serrata extract and Pycnogenol, curcumin and methylsulfonylmethane in people with OA despite the poor quality of the available studies. Few studies adequately reported possible adverse effects related to supplementation, although the products were generally recognized as safe. Further high quality trials are needed to improve the strength of evidence to support this recommendation and better guide optimal treatment of people living with OA.

Stability and anti-inflammatory activity of the reduction-resistant curcumin analog, 2,6-dimethyl-curcumin

The efficacy of the curry spice compound curcumin as a natural anti-inflammatory agent is limited by its rapid reductive metabolism in vivo. A recent report described a novel synthetic derivative, 2,6-dimethyl-curcumin, with increased stability against reduction in vitro and in vivo. It is also known that curcumin is unstable at physiological pH in vitro and undergoes rapid autoxidative transformation. Since the oxidation products may contribute to the biological effects of curcumin, we tested oxidative stability of 2,6-dimethyl-curcumin in buffer (pH 7.5). The rate of degradation was similar to curcumin. The degradation products were identified as a one-carbon chain-shortened alcohol, vanillin, and two isomeric epoxides that underwent cleavage to vanillin and a corresponding hydroxylated cleavage product. 2,6-Dimethyl-curcumin was more potent than curcumin in inhibiting NF-κB activity but less potent in inhibiting expression of cyclooxygenase-2 in LPS-activated RAW264.7 cells. 2,6-Dimethyl-curcumin and some of its degradation products covalently bound to a peptide that contains the redox-sensitive cysteine of IKKβ kinase, the activating kinase upstream of NF-κB, providing a mechanism for the anti-inflammatory activity. In RAW264.7 cells vanillin, the chain-shortened alcohol, and reduced 2,6-dimethyl-curcumin were detected as major metabolites. These studies provide new insight into the oxidative transformation mechanism of curcumin and related compounds. The products resulting from oxidative transformation contribute to the anti-inflammatory activity of 2,6-dimethyl-curcumin in addition to its enhanced resistance against enzymatic reduction.

Nutraceuticals and osteoarthritis pain

Arthritis is a chronic disease of joints. It is highly prevalent, particularly in the elderly, and is commonly associated with pain that interferes with quality of life. Because of its chronic nature, pharmacological approaches to pain relief and joint repair must be safe for long term use, a quality many current therapies lack. Nutraceuticals refer to compounds or materials that can function as nutrition and exert a potential therapeutic effect, including the relief of pain, such as pain related to arthritis, of which osteoarthritis (OA) is the most common form. Of interest, nutraceuticals have recently been shown to have potential in relieving OA pain in human clinical trials. Emerging evidence indicates nutraceuticals may represent promising alternatives for the relief of OA pain. In this paper, we will overview OA pain and the use of nutraceuticals in OA pain management, focusing on those that have been evaluated by clinical trials. Furthermore, we discuss the biologic and pharmacologic actions underlying the nutraceutical effects on pain relief based on the potential active ingredients identified from traditional nutraceuticals in OA pain management and their potential for drug development. The review concludes by sharing our viewpoints that future studies should prioritize elucidating the mechanisms of action of nutraceuticals in OA and developing nutraceuticals that not only relieve OA pain, but also mitigate OA pathology.

An Observational 1-Month Trial on the Efficacy and Safety of Promerim for Improving Knee Joint

Objective:

This study was conducted to evaluate the efficacy and tolerability of the oral intake of promerim in the elimination of acute pain and discomfort associated with knee osteoarthritis (OA).

Methods:

Single-center, 1-month, prospective, observational clinical trial. A total of 92 patients not older than 70 years were included. Patients were offered to use 720-mg promerim for the first 15 days after admission after breakfast and then 360 mg for the second 15 days. All patients were analyzed with the visual analog scale (VAS) for pain, which ranges from 0 to 10, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score before the start of treatment and 1 month after the start. Statistical analysis was performed by SPSS 15.0 software. An α level of P < .05 was assumed to be statistically significant.

Results:

This study comprised 92 patients (69 women and 23 men) with a mean age of 51.5 (range: 40-69) years. Before treatment, the mean VAS score was 5.6 ± 1.1, and after treatment, the mean VAS score was 2.6 ± 1.7. Treatment with promerim consistently showed a significant decrease in the VAS score (P < .001). The mean WOMAC score of the patients was 46.4 ± 8.2 before treatment. After treatment, the mean WOMAC score was 72.1 ± 14.4. Treatment with promerim consistently showed a significant increase in the WOMAC score (P < .001).

Conclusions:

The results of this single-center, open-label clinical study demonstrate that promerim is a viable natural treatment option for treating knee OA. We recommend that 720-mg promerim taken once daily for the first 15 days after admission and 360 mg taken once daily for the next 15 days significantly and rapidly reduced composite pain and stiffness in the knee OA within 1 month.