Recently highlighted nutraceuticals for preventive management of osteoarthritis

Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

The mechanistic role of curcumin on matrix metalloproteinases in osteoarthritis

A systematic mechanistic review was performed to determine mechanistic evidence for curcumin on pro-inflammatory matrix metalloproteinases and Osteoarthritis to understand the underlying pathophysiology, and to evaluate available human intervention evidence to inform clinical decision making. The systematic literature search was performed in 3 tranches (reviews, mechanistic, intervention studies) using PubMed, with no date limitations and using specific search terms. 65 out of 393 screened papers were accepted based on detailed inclusion and exclusion criteria. The mechanistic search was divided into three searches and the intervention searches were subdivided into four searches. Curcumin demonstrated significant inhibition of matrix metalloproteinases linked to cartilage degradation in Osteoarthritis through reduced activation of the nuclear factor kappa-B signaling pathway via suppressing phosphorylation of Iκβa and p65 nuclear translocation. Mechanistic evidence implicated matrix metalloproteinases in Osteoarthritis by decreasing Type II collagen, leading to cartilage damage. As a potential nutritional intervention for Osteoarthritis, curcumin could reduce inflammatory markers and improve pain and function scores. The evidence indicates most formulations of turmeric extract and curcumin extract, bio-enhanced and non-bio-enhanced, are effective at improving inflammatory markers and pain and function to a greater or lesser extent. Due to the high heterogeneity of the formulations, dosage, and duration of the studies, further research is needed to fully understand curcumin's potential as a promising non-pharmaceutical intervention for Osteoarthritis. This mechanism review identifies a gap in current research for the mechanism by which Type II collagen is mediated.

The short-term effect of glucosamine-sulfate, nonanimal chondroitin-sulfate, and S-adenosylmethionine combination on ultrasonography findings, inflammation, pain, and functionality in patients with knee osteoarthritis: A pilot, double-blind, randomized, placebo-controlled clinical trial

Objectives

This study aimed to investigate the efficacy of glucosamine-sulfate (GS), nonanimal chondroitin-sulfate (naCS), and S-adenosylmethionine (SAMe) combination on ultrasound findings, inflammation, pain, and functionality in knee osteoarthritis.

Patients and methods

In the prospective, randomized, double-blind, placebo-controlled pilot study conducted between August 2019 and November 2019, 120 participants (28 males, 92 females; mean age: 66.4±7.9 years; range, 42.4 to 74.5 years) were randomized at a 1:1:1 ratio to the placebo group, the first experimental group (a combination of GS, naCS, and SAMe was administered to the experimental groups. The first experimental group received 375 mg of GS, 300 mg of naCS, and 100 mg of SAMe, whereas the second experimental group received 750 mg of GS, 600 mg of naCS, and 200 mg of SAMe). Laboratory (erythrocyte sedimentation rate, C-reactive protein, tumor necrosis factor alpha, interleukin [IL]-1β, IL-6, IL-17), clinical (Visual Analog Scale [VAS], short form health survey [SF-36], the Western Ontario and McMaster Universities Arthritis Index [WOMAC], and the Tegner Lysholm Knee Scoring Scale [TLKS]), and musculoskeletal ultrasound (MSUS) assessments were performed at baseline and after three and six months.

Results

A minor increase was observed in the second experimental group after six months using ultrasonography to evaluate articular cartilage thickness (p<0.05). The investigational product's superiority in reducing osteoarthritis ultrasonographic findings was not proven. A moderately negative association was found between cartilage thickness and VAS scores at baseline (ρ=-0.36, p<0.01), while the presence of massive osteophytes on MSUS showed a low to moderate association with all clinical outcomes. There was no difference in the delta changes between groups for the VAS, TLKS, WOMAC, and SF-36. The only serum inflammatory marker outside the reference range was IL-1β, but no significant changes were observed after six months.

Conclusion

According to the results of our investigation, treatment for knee osteoarthritis should be evaluated using more objective outcomes. The most important conclusion of our study is that IP may result in a slight increase in articular cartilage thickness, which was associated with a decrease in pain intensity at baseline. Clarification of the potential influence of this combination on radiographic progression and laboratory markers of inflammation requires further exploration.

Ferroptosis as an emerging target in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease of unknown etiology. Due to the rise in the incidence rate of RA and the limitations of existing therapies, the search for new treatment strategies for RA has become a global focus. Ferroptosis is a novel programmed cell death characterized by iron-dependent lipid peroxidation, with distinct differences from apoptosis, autophagy, and necrosis. Under the conditions of iron accumulation and the glutathione peroxidase 4 (GPX4) activity loss, the lethal accumulation of lipid peroxide is the direct cause of ferroptosis. Ferroptosis mediates inflammation, oxidative stress, and lipid oxidative damage processes, and also participates in the occurrence and pathological progression of inflammatory joint diseases including RA. This review provides insight into the role and mechanism of ferroptosis in RA and discusses the potential and challenges of ferroptosis as a new therapeutic strategy for RA, with an effort to provide new targets for RA prevention and treatment.

Unraveling the role of natural functional oils in modulating osteoarthritis related complications

Osteoarthritis (OA) is a common joint disease and has been studied extensively in recent years as no promising therapy available so far for its treatment and remains a great challenge for health care specialists. Although the identification of some major mechanisms that contribute to this disease suggests a plethora of bioactive agents in tackling the associated complications yet OA's pathophysiology is still poorly understood owing to complex mechanistic changes observed. Experimental research is now exploring a wide range of therapeutically effective agents in an effort to find a way to repair OA-related joint degeneration and halt it from getting worse. Data was acquired and reviewed from most relevant and recent studies. This review summarizes the studies that are currently available and focuses on how various unconventional functional oils affect osteoarthritis and the affected joint tissues. An analysis of the recent scientific literature allowed us to highlight the potential anti-arthritic properties of edible oils and their main constituents, which seems to suggest an interesting new potential therapeutic application. Due to eccentric nature of OA, it is necessary to concentrate initially on the management of symptoms. The evidence supporting functional oils chondroprotective potential is still accumulating, underpinning a global need for more sustainable natural sources of treatment. More clinical research that focuses on the consequences of long-term treatment, possible negative effects, and epigenetic implications is necessary to get optimistic results. However, different animal or clinical studies suggest that linolenic and linoleic fatty acids decreased chondrocyte oxidative stress, cartilage breakdown, and expression of inflammatory markers. Distinct fatty acids along with minor components of oils also reduced the generation of prostaglandins and decreased oxidative stress. Furthermore, the potential roles of the main components of edible oils and possible negative results (if any) are also reported. While no severe side effects have been reported for any edible oils. Overall, these studies identify and support the use of functional oils as an adjuvant therapy for the management of OA and as a means of symptomatic alleviation for OA patients. However, to prove the effectiveness or to draw precise conclusions, high-quality clinical trials are required.

Thermo-Responsive Gel Containing Hydroxytyrosol-Chitosan Nanoparticles (Hyt@tgel) Counteracts the Increase of Osteoarthritis Biomarkers in Human Chondrocytes

Although osteoarthritis (OA) is a chronic inflammatory degenerative disease affecting millions of people worldwide, the current therapies are limited to palliative care and do not eliminate the necessity of surgical intervention in the most severe cases. Several dietary and nutraceutical factors, such as hydroxytyrosol (Hyt), have demonstrated beneficial effects in the prevention or treatment of OA both in vitro and in animal models. However, the therapeutic application of Hyt is limited due to its poor bioavailability following oral administration. In the present study, a localized drug delivery platform containing a combination of Hyt-loading chitosan nanoparticles (Hyt-NPs) and in situ forming hydrogel have been developed to obtain the benefits of both hydrogels and nanoparticles. This thermosensitive formulation, based on Pluronic F-127 (F-127), hyaluronic acid (HA) and Hyt-NPs (called Hyt@tgel) presents the unique ability to be injected in a minimally invasive way into a target region as a freely flowing solution at room temperature forming a gel at body temperature. The Hyt@tgel system showed reduced oxidative and inflammatory effects in the chondrocyte cellular model as well as a reduction in senescent cells after induction with H₂O₂. In addition, Hyt@tgel influenced chondrocytes gene expression under pathological state maintaining their metabolic activity and limiting the expression of critical OA-related genes in human chondrocytes treated with stressors promoting OA-like features. Hence, it can be concluded that the formulated hydrogel injection could be proposed for the efficient and sustained Hyt delivery for OA treatment. The next step would be the extraction of “added-value” bioactive polyphenols from by-products of the olive industry, in order to develop a green delivery system able not only to enhance the human wellbeing but also to promote a sustainable environment.

Plebeian Sage (Salvia plebeia R. Br) Extract Ameliorates Inflammation and Cartilage Degradation in Surgically Induced Osteoarthritis Rats

Osteoarthritis (OA), the most prevalent articular disease with the clinical syndrome of joint pain accompanied by varying degrees of functional limitation, reduces the quality of elderly life. In this study, the effects of Plebeian sage extract (PS) on anti-inflammatory and anti-articular cartilage degradation activities were evaluated in rats with surgically induced OA. PS supplement for 12 weeks significantly decreased Mankin scores, including inflammatory cell numbers, and improved surface cartilage damage and mean femur and tibia articular cartilage (AC) thicknesses in OA rats. PS diminished IL-1β, IL-6, TNF-α, MMP-2, MMP-3, and MMP-9, as well as lipocalin-2 levels in serum or cartilage, which were increased due to OA. The results suggested that PS decreased joint inflammation and loss of articular cartilage by suppressing provocative responses and synovial tissue decimation in the OA model. Thus, PS may be used as a novel potential therapeutic regime for OA in the elderly.

The Role of Nutraceuticals in Osteoarthritis Prevention and Treatment: Focus on n-3 PUFAs

Osteoarthritis (OA) is a disease caused by joint degeneration with massive cartilage loss, and obesity is among the risk factors for its onset, though the pathophysiological mechanisms underlying the disease and better therapeutic approach still remain to be assessed. In recent years, several nutraceutical interventions have been investigated in order to define better solutions for preventing and treating OA. Among them, polyunsaturated fatty acids (n-3 PUFAs) appear to represent potential candidates in counteracting OA and its consequences, due to their anti-inflammatory, antioxidant, and chondroinductive effects. PUFAs have been found to counteract the onset and progression of OA by reducing bone and cartilage destruction, inhibiting proinflammatory cytokine release, reactive oxygen species (ROS) generation, and the NF-κB pathway's activation. Moreover, a diet rich in n-3 PUFAs and their derivatives (maresins and resolvins) demonstrates beneficial effects on associated pain reduction. Finally, it has been shown that together with the anti-inflammatory and antioxidant properties of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, their antiapoptotic and antiangiogenic effects contribute in reducing OA development. The present review is aimed at assessing evidence suggesting the potential benefit of nutraceutical supplementation with PUFAs in OA management according to their efficacy in targeting relevant pathophysiological mechanisms responsible for inflammation and joint destruction processes, and this may represent a novel and potentially useful approach in OA prevention and treatment. For that purpose, a PubMed literature survey was conducted with a focus on some in vitro and in vivo studies and clinical trials from 2015 to 2020.

Polyphenols Targeting MAPK Mediated Oxidative Stress and Inflammation in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, systemic, autoimmune disorder, predominantly symmetric, which causes joint inflammation, cartilage degeneration and bone erosion, resulting in deformity and the loss of physical function. Although the management of RA has steadily improved, the pathophysiological mechanism is incompletely elucidated, and therapeutic options are still limited. Due to shortcomings in the efficacy or safety profiles of conventional RA therapies, therapeutic alternatives have been considered. Therefore, natural extracts containing polyphenolic compounds can become promising adjuvant agents for RA global management, due to their antioxidant, anti-inflammatory and apoptotic properties. Polyphenols can regulate intracellular signaling pathways in RA and can generate different immune responses through some key factors (i.e., MAPK, interleukins (ILs 1 and 6), tumor necrosis factor (TNF), nuclear factor light k chain promoter of activated receptor (NF-κB), and c-Jun N-terminal kinases (JNK)). The critical function of the Toll like-receptor (TLR)-dependent mitogen-activating protein kinase (MAPK) signaling pathway in mediating the pathogenic characteristics of RA has been briefly discussed. Oxidative stress can trigger a change in transcription factors, which leads to the different expression of some genes involved in the inflammatory process. This review aims to provide a comprehensive perspective on the efficacy of polyphenols in mitigating RA by inhibiting signaling pathways, suggesting future research perspectives in order to validate their use.

Ferulic acid suppresses interleukin-1β-induced degeneration of chondrocytes isolated from patients with osteoarthritis through the SIRT1/AMPK/PGC-1α signaling pathway

Background

Interleukin‐1β (IL‐1β) is involved in osteoarthritis pathogenesis and mediates a series of toxic processes including the production of matrix metalloproteinase and inflammatory regulators which are suppressed by activation of silent information regulator 1 (SIRT1). We aimed to determine the effects of ferulic acid (FA) on IL‐1β‐induced osteoarthritis chondrocyte degeneration.

Methods

We examined the effects of FA on osteoarthritis chondrocyte viability and SIRT1 activation. The impact of FA on IL‐1β‐induced osteoarthritis chondrocyte toxicity was determined by prostaglandin E2 (PGE₂), nitrite, IL‐6, components of the extracellular matrix, and markers of oxidative stress. Finally, we determined whether these effects were mediated through SIRT1 by inhibiting SIRT1 activity using SIRT1 inhibitor Sirtinol.

Results

We found that FA activated SIRT1/AMPK/PGC‐1α signaling pathway and attenuated IL‐1β‐induced osteoarthritis chondrocyte degeneration by suppressing the production of IL‐6, PGE₂, nitrite, Collagen I, Runx‐2, MMP‐1, MMP‐3, and MMP‐13, enhancing Collagen II and Aggrecan expression and inhibiting oxidative stress. Inhibition of SIRT1 by Sirtinol attenuated the protective effects of FA.

Conclusion

Our findings reveal that FA prevents IL‐1β‐induced osteoarthritis chondrocyte toxicity, which suggests that FA may be a potential therapy for osteoarthritis and warrants further investigation for its clinical application.

Magnesium in joint health and osteoarthritis

Osteoarthritis (OA) is a prevalent debilitating age-related skeletal disease. The hallmark of OA is the degradation of articular cartilage that cushions the joint during movement. It is characterized by chronic pain and disability. Magnesium, a critical trace element in the human body, plays a pivotal role in metabolism homeostasis and the energy balance. Humans obtain magnesium mainly from the diet. However, inadequate magnesium intake is not uncommon. Moreover, the magnesium status deteriorates with ageing. There has been a growing body of clinical studies pointing to an intimate relationship between dietary magnesium and OA although the conclusion remains controversial. As reported, the magnesium ion concentration is essential to determine cell fate. Firstly, the low-concentration magnesium ions induced human fibroblasts senescence. Magnesium supplementation was also able to mitigate chondrocyte apoptosis, and to facilitate chondrocyte proliferation and differentiation. In this literature review, we will outline the existing evidence in animals and humans. We will also discuss the controversies on plasma or intracellular level of magnesium as the indicator of magnesium status. In addition, we put forward the interplay between dietary magnesium intake and intestinal microbiome to modulate the inflammatory milieu in the conjecture of OA pathogenesis. This leads to an emerging hypothesis that the synergistic effect of magnesium and probiotics may open a new avenue for the prevention and treatment of OA.

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

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

The protective effects of grape seed oil on induced osteoarthritis of the knee in male rat models

Background

Osteoarthritis (OA), though being treated via various methods and medicines, is still a major healthcare concern mostly due to the increase in diagnosis of these age-related diseases. The present study aimed at investigating the effects of oral and intra articular injection of grape seed oil on OA in male rat models.

Methods and materials

Seventy male rats were selected and their anterior cruciate ligament was cut to induce OA. They were divided into 7 groups (n = 10): C1, no treatment; C2, receiving 300 mg/day of Piascledine per os (PO); C3, 1 mg sodium hyaluronate intra-articularly in days 1, 7, 14; C4, 1 mg methyl-prednisolone acetate intra-articularly; E1, avocado and grape seed oil combination (2:1, 300 mg/day) PO; E2, 500 mg/day of grape seed oil PO; E3, 200 mg/day grape seed oil intra-articularly. After 10 weeks, the rats were anesthetized and evaluated radiologically and histopathologically. P value ≤ 0.05 was considered as statistically significant.

Results

All the groups made significant differences with C1 regarding all inspected radiological criteria (P ≤ 0.05). E1 and E3 showed significantly better effects on medial femoral condyle, medial tibial condyle, joint space width, total osteophyte, and OA scores (P ≤ 0.04).

Joint surface, matrix, cell distribution, cell population viability, calcification, and subchondral bone in treatment groups had significantly better scores versus C1 (P ≤ 0.04). E1 and E3 had significantly superior results regarding joint surface, cell viability, and calcification (P ≤ 0.04).

Conclusions

Grape seed oil has protective effects, both in injectable form and PO in combination with avocado, on OA in rats. Further clinical trials are necessary.

Oxidative stress and inflammation in osteoarthritis pathogenesis: Role of polyphenols

Osteoarthritis (OA) is the most prevalent joint degenerative disease leading to irreversible structural and functional changes in the joint and is a major cause of disability and reduced life expectancy in ageing population. Despite the high prevalence of OA, there is no disease modifying drug available for the management of OA. Oxidative stress, a result of an imbalance between the production of reactive oxygen species (ROS) and their clearance by antioxidant defense system, is high in OA cartilage and is a major cause of chronic inflammation. Inflammatory mediators, such as interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) are highly upregulated in OA joints and induce ROS production and expression of matrix degrading proteases leading to cartilage extracellular matrix degradation and joint dysfunction. ROS and inflammation are interdependent, each being the target of other and represent ideal target/s for the treatment of OA. Plant polyphenols possess potent antioxidant and anti-inflammatory properties and can inhibit ROS production and inflammation in chondrocytes, cartilage explants and in animal models of OA. The aim of this review is to discuss the chondroprotective effects of polyphenols and modulation of different molecular pathways associated with OA pathogenesis and limitations and future prospects of polyphenols in OA treatment.

Valgus knee bracing may have no long-term effect on pain improvement and functional activity in patients with knee osteoarthritis: a meta-analysis of randomized trials

Background

Knee osteoarthritis (KOA), with a high incidence in old-age population, adversely affects their life quality. The valgus knee bracing is an important physical therapy for KOA, but its clinical effects on pain release and functional improvement remained unclear. This meta-analysis is to systematically evaluate the clinical outcomes of valgus knee bracing in patients with KOA.

Methods

A meta-analysis of clinical randomized controlled trials (RCTs) on pain and functional changes in patients with KOA after using valgus knee braces. The search period was ranged from the inception of the database to May 2020. The enrolled research databases included PubMed, Embase, and Web of Science databases. Two investigators independently formulated inclusion criteria and exclusion criteria and screened and determined the final enrolled literature. Then the outcome indicators were extracted and organized from the included literature, and the risk of bias was assessed by Cochrane Handbook 5.0.1.

Results

A total of 10 articles were included in this study, including 739 patients. Eight articles were related to the visual analog scale (VAS) pain score, and the results showed that RR = − 0.29, 95% CI − 0.73, 0.15], P = 0.20; four articles were related to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function score, and the results showed that RR = − 0.15, 95% CI [− 0.41, 0.11], P = 0.26; two articles were related to the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the results showed that RR = 0.58, 95% CI [− 4.25, 5.42], P = 0.81; and three articles were related to the KOOS Activities of Daily Living (KOOS-ADL), and the results showed that RR = 0.04, 95% CI [− 0.62, 0.69], P = 0.91. These results indicated that the valgus knee bracing has no statistical significance in pain and functional activity improvement of patients with KOA. The subgroup analysis showed that the follow-up time was the source of the heterogeneity of the VAS pain score.

Conclusion

Our current evidence suggests that valgus knee bracing may not improve pain release and function activates in KOA patients in the long-term period, but only being beneficial to the short-term rehabilitation.

Are Stem Cells Derived from Synovium and Fat Pad Able to Treat Induced Knee Osteoarthritis in Rats?

Background

Osteoarthritis (OA) is a chronic disease and a significant cause of joint pain, tenderness, and limitation of motion. At present, no specific treatment is available, and mesenchymal stem cells (MSCs) have shown promising potentials in this regard. Herein, we aimed to evaluate the repairing potentials of stem cells derived from the synovium and fat pad in the treatment of OA.

Methods

Twenty-eight male rats (220 ± 20 g, aged 10-12 weeks), were randomly divided into four groups (n = 7): C1: nontreated group, C2: Hyalgan-treated group, E1: adipose tissue-derived stem cell-treated group, and E2: synovial membrane-based stem cell-treated group. Collagenase type II was injected into the left knee; after eight weeks, OA was developed. Then, stem cells were injected, and rats were followed for three months. Afterward, specimens and radiological images were investigated. p value ≤ 0.05 was set as statistically significant.

Results

Compared to the C1 group, the E1 and E2 groups showed significantly better results in all six pathological criteria as well as joint space width and osteophytes of medial tibial, medial femoral, and medial fabellar condyles (p ≤ 0.001). Similarly, compared to the C2 group, the E1 and E2 groups had better scores regarding surface, matrix, cell distribution, and cell population viability (p < 0.05). E2 showed considerably higher scores compared to C2 regarding subchondral bone and cartilage mineralization (p < 0.05). The joint space width was similar between the C2 and E groups.

Conclusion

Treatment of OA with MSCs, particularly synovial membrane-derived stem cells, not only prevented but also healed OA of the knee to some extent in comparison to the Hyalgan and nontreatment groups.

Osteoarthritis treatment with a novel nutraceutical acetylated ligstroside aglycone, a chemically modified extra-virgin olive oil polyphenol

Recent studies have shown that dietary patterns confer protection from certain chronic diseases related to oxidative stress, the immune system and chronic low-grade inflammatory diseases. The aim of this study was to evaluate the anti-inflammatory potential and the capacity to attenuate cartilage degradation using extra-virgin olive oil–derived polyphenols for the treatment of osteoarthritis. Results show that both nutraceuticals ligstroside aglycone and acetylated ligstroside aglycone showed an anti-inflammatory profile. Acetylated ligstroside aglycone significantly reduced the expression of pro-inflammatory genes including NOS2 and MMP13 at both RNA and protein levels; decreased nitric oxide release; and, importantly, reduced proteoglycan loss in human osteoarthritis cartilage explants. Our study demonstrated that a new synthetic acetylated ligstroside aglycone derivative offers enhanced anti-inflammatory profile than the natural nutraceutical compound in osteoarthritis. These results substantiate the role of nutraceuticals in osteoarthritis with implications for therapeutic intervention and our understanding of osteoarthritis pathophysiology.

Impact of miR-SNP rs2910164 on miR-146a expression in osteoarthritic chondrocytes

PURPOSE

MiR-146a acts as a negative inflammatory mediator in different diseases and has been implicated in osteoarthritis (OA) pathogenesis. In our study, we investigated the association between miR-SNP rs2910164 and OA susceptibility and its role on the expression of miR-146a, inflammatory and catabolic mediators in osteoarthritic chondrocytes.

MATERIALS AND METHODS

Genetic association analysis was performed in 1688 knee OA patients and healthy individuals of Greek origin. Genomic DNA was extracted from blood and genotyped for rs2910164 (G > C) using Restriction-Fragment Length Polymorphism (RFLP). Total RNA was extracted from chondrocytes of 18 OA patients and miR-146a, IL-1 Receptor-Associated Kinase 1 (IRAK-1), TNF Receptor-Associated Factor 6 (TRAF-6), A Disintegrin and Metalloproteinase with Thrombospondin Motifs 5 (ADAMTS-5), Matrix Metalloproteinase-13 (MMP-13), Interleukin-6 (IL-6), Interleukin-1 Beta (IL-1β) and Tumor Necrosis Factor-Alpha (TNF-α) expression was evaluated using quantitative Real-Time PCR (qRT-PCR).

RESULTS

OA patients carrying rs2910164-GC and CC genotypes did not have an increased risk for OA development compared to GG genotype carriers. MiR-146a expression in OA chondrocytes was significantly lower in patients with rs2910164-GC genotype than in the GG carriers. OA patients carrying the rs2910164-GC genotype in their chondrocytes exhibited increased IRAK-1, TRAF-6, MMP-13, IL-1β and IL-6 expression levels compared with rs2910164-GG carriers.

CONCLUSION

We demonstrate, for the first time, that miR-SNP rs2910164 in miR-146a gene is associated with reduced miR-146a and increased inflammatory and catabolic mediators' expression in OA chondrocytes. Our data imply that genetic variations in miRNAs linked to OA pathogenesis may regulate their expression levels, suggesting new therapeutic strategies for patients with cartilage diseases.

Nutrition, osteoarthritis and cartilage metabolism

BACKGROUND

Osteoarthritis (OA) is a degenerative joint disease and a leading cause of adult disability. There is no cure for OA and there is no effective treatment to stop its progression. Current pharmacologic treatments such as analgesics and non-steroidal anti-inflammatory drugs may improve the pain and offer some relief but they do not affect the progression of the disease. The chronic intake of these drugs may result in severe adverse events. The aim of this review is to revise the effects of nutrition on cartilage metabolism and OA progression.

METHODS

A systematic literature search was performed including those related to macro- and micro-nutrients' actions on cartilage and OA outcome. We selected peer-reviewed articles reporting the results of human clinical trials.

RESULTS

Glucosamine and chondroitin sulfate have shown to delay OA knee progression in several clinical trials. The effectiveness of some products considered nutraceuticals has been widely reviewed in the literature. This article presents a general description of the effectiveness and mechanism of action of nutrients, vitamins, antioxidants and other natural components considered as part of the normal diet. Many in vitro studies indicate the efficacy of specific nutrients in cartilage metabolism and its involvement in OA. However, rigorous clinical studies needed to evaluate the efficacy of these compounds in humans are still missing. The influence of nutrients and diet on the metabolism of cartilage and OA could represent a long-term coadjuvant alternative in the management of patients with OA. Effects of diet modifications on lipid and cholesterol profiles, adequate vitamin levels and weight reduction in obese patients could influence the course of the disease.

CONCLUSION

This review demonstrates that nutrition can improve the symptoms of OA. Glucosamine and chondroitin sulfate have shown robustly to delay the progression of knee OA in several well-designed studies, however more controlled clinical trials are needed to conclude that nutritional changes slow down the progression of the disease.