The effect of pomegranate juice on clinical signs, matrix metalloproteinases and antioxidant status in patients with knee osteoarthritis

The power of Punica granatum: A natural remedy for oxidative stress and inflammation; a narrative review

ETHNOPHARMACOLOGICAL RELEVANCE

Pomegranate 'Punica granatum' offers multiple health benefits, including managing hypertension, dyslipidemia, hyperglycemia, insulin resistance, and enhancing wound healing and infection resistance, thanks to its potent antioxidant and anti-inflammatory properties. It has been symbolized by life, health, femininity, fecundity, and spirituality.

AIM OF THE STUDY

Although laboratory and animal studies have been conducted on the healing effects of pomegranate, there needs to be a comprehensive review on its anti-oxidative and anti-inflammatory effects in chronic disorders. We aim to provide a comprehensive review of these effects based on in-vitro, in-vivo, and clinical studies conducted in managing various disorders.

MATERIALS AND METHODS

A comprehensive search of in-vitro, in-vivo, and clinical findings of pomegranate and its derivatives focusing on the highly qualified original studies and systematic reviews are carried out in valid international web databases, including Web of Science, PubMed, Scopus, and Cochrane Library.

RESULTS

Relevant studies have demonstrated that pomegranate and its derivatives can modulate the expression and activity of several genes, enzymes, and receptors through influencing oxidative stress and inflammation pathways. Different parts of pomegranate; roots, bark, blossoms, fruits, and leaves contain various bioactive compounds, such as polyphenols, flavonoids, anthocyanins, and ellagitannins, that have preventive and therapeutic effects against many disorders such as cardiovascular diseases, diabetes, neurological diseases, and cancers without any serious adverse effects.

CONCLUSIONS

Most recent scientific evidence indicates that all parts of the pomegranate can be helpful in treating a wide range of chronic disorders due to its anti-oxidative and anti-inflammatory activities. Since the safety of pomegranate fruit, juice, and extracts is established, further investigations can be designed by targeting its active antioxidant and anti-inflammatory constituents to discover new drugs.

Diet modification reduces pain and improves function in adults with osteoarthritis: a systematic review

BACKGROUND

The effect of dietary modifications on pain and joint function in adults with osteoarthritis (OA) is an emerging area of study. This systematic review aimed to evaluate if adults with OA who consume diets with a higher proportion of plant phenols and omega-3 fatty acids would have less pain and improved joint function than those with a higher proportion of saturated fatty acids, omega-6 fatty acids and refined carbohydrates.

METHODS

Database searches of CINAHL (EBSCO), Clinical Trials (NIH-NLM), Cochrane Library (Wiley), Dissertation & Thesis Global (ProQuest), Embase (Elsevier), Medline (OVID), PubMed (NLM), Scopus (Elsevier), Web of Sciences (Clarivate) for clinical trials identified 7763 articles published between January 2015 and May 2023. After an independent review of the articles, seven randomised clinical trials and one nonrandomised clinical trial were included in the analysis. Because of the heterogeneity of the outcome measures, a meta-analysis was not possible.

RESULTS

Participants who were instructed to consume high-phenol/high-omega-3 fatty acid diets reported significant improvements in pain and physical function scores. The greatest improvement was reported by those who consumed a diet that had the most omega-3 fatty acids.

CONCLUSION

Because of the high risk of bias, the strength of the evidence is limited. However, there is evidence that counselling adults with OA to replace refined grains and processed foods with whole plant foods, fish and plant oils may have a favourable effect on pain and physical function. Routine follow-up care regarding these diet modifications may be necessary to ensure adherence to this therapy.

Effects of Pomegranate (Punica granatum L.) Peel Extract Supplementation on Markers of Inflammation and Serum Matrix Metalloproteinase 1 in Women With Knee Osteoarthritis: A Randomized Double-Blind Placebo-Controlled Study

Objective

Osteoarthritis (OA) as a common musculoskeletal disorder is the main cause of disability in the world. The present study aimed to evaluate the effects of pomegranate peel extract (PPE) on some inflammatory markers and matrix maloproteinase1 (MMP1) in women with knee OA.

Methods

Sixty obese women with knee OA aged 38 to 60 years were included in this clinical trial. The women were allocated into intervention (n = 30) and placebo (n = 30) groups along with standard drug therapy receiving 500 mg PPE or placebo twice daily for 8 weeks, respectively. Three-day food records, anthropometric measurements, fasting blood samples, and physical activity questionnaires were gathered at the baseline and the end of the study.

Results

The supplementation of PPE significantly reduced the serum high-sensitivity C-reactive protein (hs-CRP), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB), MMP1, and monocyte chemoattractant protein-1 (MCP-1) levels of the patients within the intervened group (all, P < .05) and compared with the placebo (P = .002, .045, .040, and .003, respectively) at the end of the study. The serum NF-ĸB levels significantly increased within the placebo group at the end of the trial (P = .002). Changes in other variables in the placebo group were not significant (P > .05).

Conclusions

The findings of this clinical trial indicated that PPE supplementation decreased serum inflammatory markers including hs-CRP, NF-ĸB, and MCP-1 and MMP1 levels in women with knee OA. PPE supplementation may be useful as a part of an integrated approach to modulating inflammatory complications in women with knee OA.

Bioactives and their roles in bone metabolism of osteoarthritis: evidence and mechanisms on gut-bone axis

Bioactives significantly modify and maintain human health. Available data suggest that Bioactives might play a beneficial role in chronic inflammatory diseases. Although promised, defining their mechanisms and opting to weigh their benefits and limitations is imperative. Detailed mechanisms by which critical Bioactives, including probiotics and prebiotics such as dietary lipids (DHA, EPA, alpha LA), vitamin D, polysaccharides (fructooligosaccharide), polyphenols (curcumin, resveratrol, and capsaicin) potentially modulate inflammation and bone metabolism is limited. Certain dietary bioactive significantly impact the gut microbiota, immune system, and pain response via the gut-immune-bone axis. This narrative review highlights a recent update on mechanistic evidence that bioactive is demonstrated demonstrated to reduce osteoarthritis pathophysiology.

Evidence-Based Dietary Practices to Improve Osteoarthritis Symptoms: An Umbrella Review

While there is some research investigating whole foods or diets that are easily understood and accessible to patients with osteoarthritis, specific nutrients or nutraceuticals are more commonly identified. Unfortunately, guidelines and evidence surrounding individual nutrients, extracts, and nutraceuticals are conflicting and are more difficult to interpret and implement for patients with osteoarthritis. The purpose of this umbrella review is to provide a comprehensive understanding of the existing evidence of whole foods and dietary patterns effects on osteoarthritis-related outcomes to inform evidence-based recommendations for healthcare professionals and identify areas where more research is warranted. A literature search identified relevant systematic reviews/meta-analyses using five databases from inception to May 2022. Five systematic reviews/meta-analyses were included in the current umbrella review. Most evidence supported the Mediterranean diet improving osteoarthritis-related outcomes (e.g., pain, stiffness, inflammation, biomarkers of cartilage degeneration). There was little to no evidence supporting the effects of fruits and herbs on osteoarthritis-related outcomes; however, there was some suggestion that specific foods could potentiate symptom improvement through antioxidative mechanisms. The overall lack of homogeneity between the studies limits the conclusions that can be made and highlights the need for quality research that can identify consumer-accessible foods to improve osteoarthritis-related symptoms.

Dietary anthocyanins balance immune signs in osteoarthritis and obesity - update of human in vitro studies and clinical trials

Anthocyanins are known to change ligand-receptor bindings, cell membrane permeability, and intracellular signaling pathways. The beneficial effects of dietary anthocyanins have been chronologically demonstrated in interventional and observational studies, including fourteen human chondrocyte studies and related cell culture assays, nineteen human clinical trials in osteoarthritis patients, seven in vivo obesity assays, nineteen in vitro assays in preadipocytes and related cells, and twenty-two clinical trials in overweight/obese subjects, which are critically discussed in this update. Strawberries, cherries, berries, pomegranate, tropical fruits, rosehip, purple rice, purple corn, red beans, and black soybean, together with cyanidin, delphinidin, malvidin, peonidin, some 3-O-glycosides, metabolites, and acylated anthocyanins from a potato cultivar have shown the best outcomes. The set of these five key tests and clinical trials, taken together, contributes to the understanding of the underlying mechanisms and pathways involved. Furthermore, this set shows the value of anthocyanins in counteracting the progression of osteoarthritis/obesity. The interplay between the inflammation of osteoarthritis and obesity, and the subsequent regulation/immunomodulation was performed through isolated and food anthocyanins. The antioxidant, anti-inflammatory, and immunomodulatory properties of anthocyanins explain the findings of the studies analyzed. However, further interventional studies should be conducted to finally establish the appropriate doses for anthocyanin supplementation, dose-response, and length of consumption, to include dietary recommendations for osteoarthritis/obese patients for preventive and management purposes.

Higher dietary phytochemical index is associated with lower odds of knee osteoarthritis

Previous studies have shown that adherence to dietary patterns rich in plant-based foods may reduce the odds of osteoarthritis; however, limited data are available on the association of consumption of diets rich in phytochemicals and odds of knee osteoarthritis (KOA). In this case–control study conducted in Iran, we aimed to investigate whether a higher dietary phytochemical index (DPI) is associated with decreased odds of having KOA. A total of 124 cases aged 20–60 years diagnosed with bilateral primary KOA according to the American College of Rheumatology criteria and 124 controls frequency-matched on age, sex, and body mass index (BMI) were included in the study. A validated food frequency questionnaire (FFQ) was used to collect information on dietary intakes. To calculate DPI scores, the dietary energy derived from foods rich in phytochemicals (kcal) was divided by the participant’s total daily energy intake (kcal). Patients with KOA had lower intakes of dietary fiber (P = 0.004), vitamin A (P = 0.007), vitamin C (P = 0.001), and folate (P = 0.021) compared to controls. In the crude model, individuals in the third tertile of DPI had 65% lower odds of having KOA compared to those in the first tertile (OR 0.35, 95% CI 0.19 to 0.67, P-trend = 0.001). After adjustment for potential confounders, including age, sex, physical activity, smoking, and supplement use, this inverse association remained significant (OR 0.37, 95% CI 0.19 to 0.73, P-trend = 0.004). After further adjustment for BMI, this inverse association between DPI and odds of KOA also remained significant (OR 0.35, 95% CI 0.18 to 0.69, P-trend = 0.003). These findings suggest that adherence to a phytochemical-rich diet, as indicated by the increasing DPI score, is associated with lower odds of KOA.

Effects of diet on the outcomes of rheumatic and musculoskeletal diseases (RMDs): systematic review and meta-analyses informing the 2021 EULAR recommendations for lifestyle improvements in people with RMDs

BACKGROUND

A EULAR taskforce was convened to develop recommendations for lifestyle behaviours in rheumatic and musculoskeletal diseases (RMDs). In this paper, the literature on the effect of diet on the progression of RMDs is reviewed.

METHODS

Systematic reviews and meta-analyses were performed of studies related to diet and disease outcomes in seven RMDs: osteoarthritis (OA), rheumatoid arthritis (RA), systemic lupus erythematosus, axial spondyloarthritis, psoriatic arthritis, systemic sclerosis and gout. In the first phase, existing relevant systematic reviews and meta-analyses, published from 2013 to 2018, were identified. In the second phase, the review was expanded to include published original studies on diet in RMDs, with no restriction on publication date. Systematic reviews or original studies were included if they assessed a dietary exposure in one of the above RMDs, and reported results regarding progression of disease (eg, pain, function, joint damage).

RESULTS

In total, 24 systematic reviews and 150 original articles were included. Many dietary exposures have been studied (n=83), although the majority of studies addressed people with OA and RA. Most dietary exposures were assessed by relatively few studies. Exposures that have been assessed by multiple, well conducted studies (eg, OA: vitamin D, chondroitin, glucosamine; RA: omega-3) were classified as moderate evidence of small effects on disease progression.

CONCLUSION

The current literature suggests that there is moderate evidence for a small benefit for certain dietary components. High-level evidence of clinically meaningful effect sizes from individual dietary exposures on outcomes in RMDs is missing.

Effects of Punica granatum Fruit (a Super Food) Juice on Human Health

Background:

Pomegranate (Punica granatum L.), one of the oldest known edible fruits, is nowadays broadly consumed throughout the world. Its fruits and seed are rich in many bioactive compounds, as polyphenols, and the scientific interest in this plant has been constantly growing in recent years.

Introduction:

Pomegranate fruit and its juice have been shown to have health benefits relating to their antioxidant and anti-inflammatory properties. They are used in alternative medicine as adaptogens and ergogens protecting against many neurological, cardiovascular, gastrointestinal, liver, and skin disorders.

Methods:

Given the amount of evidence, this narrative review does not seek to supply a comprehensive summary of all study findings, but rather focuses on human clinical trials related the last five years. In this regard, we have performed a check in MEDLINE, and clinical trials presented in this time are summarized.

Result:

The use of pomegranate as table fruit or juice, rich source of polyphenols, can so be recommended in human nutrition for its benefic properties. The consumption of pomegranate fruit symbolizes a promising therapeutic approach to avert many chronic syndromes.

Conclusion:

Importantly, the findings call for the need for a larger, rigorously designed human clinical trials to allow continued investigation into the potential specific effects of pomegranate fruit, and to obtain the best dose and duration of supplementation with pomegranate juice.

Ellagic Acid: A Review on Its Natural Sources, Chemical Stability, and Therapeutic Potential

Ellagic acid (EA) is a bioactive polyphenolic compound naturally occurring as secondary metabolite in many plant taxa. EA content is considerable in pomegranate (Punica granatum L.) and in wood and bark of some tree species. Structurally, EA is a dilactone of hexahydroxydiphenic acid (HHDP), a dimeric gallic acid derivative, produced mainly by hydrolysis of ellagitannins, a widely distributed group of secondary metabolites. EA is attracting attention due to its antioxidant, anti-inflammatory, antimutagenic, and antiproliferative properties. EA displayed pharmacological effects in various in vitro and in vivo model systems. Furthermore, EA has also been well documented for its antiallergic, antiatherosclerotic, cardioprotective, hepatoprotective, nephroprotective, and neuroprotective properties. This review reports on the health-promoting effects of EA, along with possible mechanisms of its action in maintaining the health status, by summarizing the literature related to the therapeutic potential of this polyphenolic in the treatment of several human diseases.

Do Pomegranate Hydrolyzable Tannins and Their Derived Metabolites Provide Relief in Osteoarthritis? Findings from a Scoping Review

Osteoarthritis (OA) is the most common form of arthritis affecting both the elderly and the middle-aged population. Although various therapeutics have been developed to arrest the structural deterioration of cartilage, the current treatments are limited to delay the progress of OA clinically. Therefore, it is pivotal to study new therapeutic agents for chondroprotection and the prevention of cartilage degeneration. Hydrolyzable tannin (HT)-containing foods aroused considerable interest in recent years for their relevant anti-inflammatory effects. The focus of this scoping review is to provide an overview of the evidence of the therapeutic potential of HTs and their metabolites in preventing or alleviating the course of OA. A broad search of PubMed and Scopus databases on this topic resulted in 156 articles. After the exclusion of reviews and not relevant records, 31 articles were retrieved. Although only some papers did not consider the biotransformation of HTs, most recent studies also have investigated the effect of HT metabolites. Further larger clinical trials, with an in-deep analysis of HT metabolization, are still needed to unravel the potential benefits of these compounds in OA, paving the way towards the development of a dietary strategy for the improvement of pro-inflammatory cytokine-induced chondrocyte dysfunctions and injuries.

Systematic review of the effects of pomegranate (Punica granatum) on osteoarthritis

Background: Considering limitations of the established osteoarthritis (OA) medications, attention to adjuvant and complementary treatments has increased in OA individuals. Recent investigations have reported advantages of pomegranate in OA and indicate that pomegranate can be a therapeutic option; nevertheless, no systematic review exists regarding OA and pomegranate. Therefore, we systematically studied accessible researches regarding pomegranate and OA in human, animal, and in vitro models and likely mechanistic pathways. Methods: Present systematic review study was recorded on the international prospective register of systematic reviews database. Electronic databases (Scopus, PubMed, Embase, WOS, ProQuest) and search engine Google Scholar were searched until February 2021. Search alerts were turned on to recognize papers published following the primary search. Two investigators independently searched using MESH and non-MESH words in title, abstract, and keywords. Inclusion criteria were related clinical, animal, and in vitro studies published in any language as a full text. Exclusion criteria were reviews, book chapters, conference abstracts, and articles regarding pomegranate in health problems other than OA. Hand searching was used to check the references or citations of eligible papers and grey literature (theses etc.) to find potential researches. Results: Twenty-three articles were included in our systematic review. Human, animal, and in vitro researches demonstrated favorable properties of pomegranate in improving clinical features and reducing inflammatory, oxidative stress, and apoptosis markers in OA. Conclusion: Present paper provides convincing evidence about the efficacy of pomegranate in OA and gives a justification for the importance of additional clinical studies.

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

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

Therapeutic Effects of Punica granatum (Pomegranate): An Updated Review of Clinical Trials

Punica granatum L. belongs to the Punicaceae family which is distributed around the world. Different parts of pomegranate like seed, peel, juice, and leaves are rich in potential bioactive compounds. These plants have found application in traditional medicine such as in treatment of gastrointestinal, cardiovascular, and endocrine diseases, among others. The present review aimed to summarize the current research on the traditional and scientific applications of P. granatum with regard to the phytochemical content and clinical applications that may be useful for future drug development. Information about P. granatum was obtained from local classic herbal literature and electronic databases, such as PubMed, Scopus, and ScienceDirect. Several phytochemical constituents including polyphenolics, flavonoids, anthocyanosides, alkaloids, lignans, and triterpenes have been reported from the plant. Randomized clinical trials have provided evidence as to the pharmacological activities of pomegranate in several diseases including diabetes, cardiovascular disease, oral cavity disorders, endocrine disorders, and cancer. The present review has provided an insight into the traditional applications of the plants, and some of them have been validated by scientific evidence, particularly their applications as treatment of cardiovascular and endocrine diseases.

The Implication of Reactive Oxygen Species and Antioxidants in Knee Osteoarthritis

Knee osteoarthritis (KOA) is a chronic multifactorial pathology and a current and essential challenge for public health, with a negative impact on the geriatric patient's quality of life. The pathophysiology is not fully known; therefore, no specific treatment has been found to date. The increase in the number of newly diagnosed cases of KOA is worrying, and it is essential to reduce the risk factors and detect those with a protective role in this context. The destructive effects of free radicals consist of the acceleration of chondrosenescence and apoptosis. Among other risk factors, the influence of redox imbalance on the homeostasis of the osteoarticular system is highlighted. The evolution of KOA can be correlated with oxidative stress markers or antioxidant status. These factors reveal the importance of maintaining a redox balance for the joints and the whole body's health, emphasizing the importance of an individualized therapeutic approach based on antioxidant effects. This paper aims to present an updated picture of the implications of reactive oxygen species (ROS) in KOA from pathophysiological and biochemical perspectives, focusing on antioxidant systems that could establish the premises for appropriate treatment to restore the redox balance and improve the condition of patients with KOA.

Dietary Interventions with Polyphenols in Osteoarthritis: A Systematic Review Directed from the Preclinical Data to Randomized Clinical Studies

Osteoarthritis (OA) is the most common form of arthritis and a major cause of limited functionality and thus a decrease in the quality of life of the inflicted. Given the fact that the existing pharmacological treatments lack disease-modifying properties and their use entails significant side effects, nutraceuticals with bioactive compounds constitute an interesting field of research. Polyphenols are plant-derived molecules with established anti-inflammatory and antioxidant properties that have been extensively evaluated in clinical settings and preclinical models in OA. As more knowledge is gained in the research field, an interesting approach in the management of OA is the additive and/or synergistic effects that polyphenols may have in an optimized supplement. Therefore, the aim of this review was to summarize the recent literature regarding the use of combined polyphenols in the management of OA. For that purpose, a PubMed literature survey was conducted with a focus on some preclinical osteoarthritis models and randomized clinical trials on patients with osteoarthritis from 2018 to 2021 which have evaluated the effect of combinations of polyphenol-rich extracts and purified polyphenol constituents. Data indicate that combined polyphenols may be promising for the treatment of osteoarthritis in the future, but more clinical trials with novel approaches in the identification of the in-between relationship of such constituents are needed.

Dietary Interventions Are Beneficial for Patients with Chronic Pain: A Systematic Review with Meta-Analysis

Background

The standard Western diet is high in processed hyperpalatable foods that displace nutrient-dense whole foods, leading to inflammation and oxidative stress. There is limited research on how these adverse metabolic drivers may be associated with maladaptive neuroplasticity seen in chronic pain and whether this could be attenuated by a targeted nutritional approach. The aim of this study was to review the evidence for whole-food dietary interventions in chronic pain management.

Method

A structured search of eight databases was performed up to December 2019. Two independent reviewers screened studies and evaluated risk of bias by using the National Institutes of Health assessment tool for controlled or pre–post studies and the Joanna Briggs checklist for case reports. A meta-analysis was performed in Review Manager.

Results

Forty-three studies reporting on 48 chronic pain groups receiving a whole-food dietary intervention were identified. These included elimination protocols (n = 11), vegetarian/vegan diets (n = 11), single-food changes (n = 11), calorie/macronutrient restriction (n = 8), an omega-3 focus (n = 5), and Mediterranean diets (n = 2). A visual analog scale was the most commonly reported pain outcome measure, with 17 groups reporting a clinically objective improvement (a two-point or 33% reduction on the visual analog scale). Twenty-seven studies reported significant improvement on secondary metabolic measures. Twenty-five groups were included in a meta-analysis that showed a significant finding for the effect of diet on pain reduction when grouped by diet type or chronic pain type.

Conclusion

There is an overall positive effect of whole-food diets on pain, with no single diet standing out in effectiveness. This suggests that commonalities among approaches (e.g., diet quality, nutrient density, weight loss) may all be involved in modulating pain physiology. Further research linking how diet can modulate physiology related to pain (such as inflammation, oxidative stress, and nervous system excitability) is required.

Effects of Nutritional Interventions in the Control of Musculoskeletal Pain: An Integrative Review

Food consumption has significant positive effects on an individual’s health status, including the reduction of symptoms associated with musculoskeletal pain. However, specific food groups indicated for the treatment of pain are not yet determined. Hence, this review aimed to analyze the effects of nutritional interventions with specific diets, oils and/or fatty acids, and foodstuffs in natura in the reduction of musculoskeletal pain. An integrative review was conducted in the following databases: Embase, PubMed, LILACS, and Google Scholar. Clinical trials written in English, Spanish, and Portuguese and published between 2000 and March 2020 were included in this review. Seventeen studies were included. Among these, a reduction of musculoskeletal pain with different types of nutritional interventions, such as vegan and Mediterranean diets and the consumption of blueberry, strawberry, passion fruit peel extract, argan oil, fish oil (omega-3), olive oil, and undenatured type II collagen and vitamin D gel capsules, was observed in 14 studies. Eight studies evaluated the profiles of several inflammatory markers, and of these, decreased interleukin (IL)-6, IL-1β, and tumor necrosis factor-α levels were observed in two studies. This review suggests that different nutritional interventions with specific diets, oils and/or fatty acids, and foodstuffs in natura reduce musculoskeletal pain, specifically in adults with osteoarthritis. Besides pain improvement, nutritional interventions, including the consumption of strawberry and vitamin D gel capsules, decrease the levels of several inflammatory markers.

Polyphenols suppress inducible oxidative stress in human osteoarthritic and bovine chondrocytes

Reactive oxygen species (ROS) and nitric oxide (NO) have been implicated in chondrocyte senescence and cartilage aging, pathogenesis of osteoarthritis (OA), and rheumatoid arthritis. Naturally occurring polyphenolic compounds (PPCs), such as curcumin (turmeric), resveratrol (grape), and epigallocatechin-3-gallate (EGCG) (green tea), have been known for their anti-inflammatory and chondroprotective effects. However, the potential protective effects of these PPCs against oxidative stress in chondrocytes are unclear. To investigate this, bovine articular chondrocytes and human osteoarthritic chondrocytes were pre-treated with PPCs at varying concentrations, and then exposed to hydrogen peroxide (H2O2) as an ROS inducer or S-nitroso-N-acetylpenicillamine (SNAP) as a NO donor. Alternatively, chondrocytes were co-treated with polyphenols and H2O2. Intracellular ROS/NO were measured using a fluorescent dye technique (H2DCF-DA for ROS; DAF-FM for NO). Our findings showed that PPC pre-/co-treatment inhibited both H2O2-induced ROS and SNAP-induced NO at different concentrations in both bovine chondrocytes and human osteoarthritic chondrocytes. Curcumin also increased glutathione peroxidase activity in the presence of H2O2 in bovine chondrocytes. Taken together, these findings indicate that PPCs are capable of suppressing oxidative stress- induced responses in chondrocytes, which may have potential therapeutic value for OA clinical application.

Herbal Remedies as Potential in Cartilage Tissue Engineering: An Overview of New Therapeutic Approaches and Strategies

It is estimated that by 2023, approximately 20% of the population of Western Europe and North America will suffer from a degenerative joint disease commonly known as osteoarthritis (OA). During the development of OA, pro-inflammatory cytokines are one of the major causes that drive the production of inflammatory mediators and thus of matrix-degrading enzymes. OA is a challenging disease for doctors due to the limitation of the joint cartilage's capacity to repair itself. Though new treatment approaches, in particular with mesenchymal stem cells (MSCs) that integrate the tissue engineering (TE) of cartilage tissue, are promising, they are not only expensive but more often do not lead to the regeneration of joint cartilage. Therefore, there is an increasing need for novel, safe, and more effective alternatives to promote cartilage joint regeneration and TE. Indeed, naturally occurring phytochemical compounds (herbal remedies) have a great anti-inflammatory, anti-oxidant, and anabolic potential, and they have received much attention for the development of new therapeutic strategies for the treatment of inflammatory diseases, including the prevention of age-related OA and cartilage TE. This paper summarizes recent research on herbal remedies and their chondroinductive and chondroprotective effects on cartilage and progenitor cells, and it also emphasizes the possibilities that exist in this research area, especially with regard to the nutritional support of cartilage regeneration and TE, which may not benefit from non-steroidal anti-inflammatory drugs (NSAIDs).

Pomegranate juice as a functional food: a comprehensive review of its polyphenols, therapeutic merits, and recent patents

Pomegranate (Punica granatum) is an ancient perennial plant species of the Punicaceae family and is regarded as the 'miracle fruit' for its seeds being consumed as food, juice and as a functional food. Significant modern pharmacological and clinical evidence has highlighted the wide medicinal applications of pomegranate fruit parts and its juice. Pomegranate juice (PJ) that is superior to other fruit juices is a fortified source of dietary polyphenols with potential antioxidant capacity. Polyphenols of PJ include tannins, anthocyanins, and flavonoids. The presence of these beneficial phytochemicals is directly linked to its favourable health benefits viz., obesity and diabetes management and anti-inflammatory effects. This comprehensive review capitalizes on PJ with emphasis on the interrelationship between its holistic chemical composition, metabolism and biological effects. Moreover, the review recapitulates on the diverse health benefits of PJ and related patents in the field of PJ production to ensure the best produced juice quality.

Unraveling Natural Products' Role in Osteoarthritis Management-An Overview

The natural process of aging gradually causes changes in living organisms, leading to the deterioration of organs, tissues, and cells. In the case of osteoarthritis (OA), the degradation of cartilage is a result of both mechanical stress and biochemical factors. Natural products have already been evaluated for their potential role in the prevention and treatment of OA, providing a safe and effective adjunctive therapeutic approach. This review aimed to assess the therapeutic potential of natural products and their derivatives in osteoarthritis via a systematic search of literature after 2008, including in vitro, in vivo, ex vivo, and animal models, along with clinical trials and meta-analysis. Overall, 170 papers were obtained and screened. Here, we presented findings referring to the preventative and therapeutic potential of 17 natural products and 14 naturally occurring compounds, underlining, when available, the mechanisms implicated. The nature of OA calls to initially focus on the management of symptoms, and, in that context, several naturally occurring compounds have been utilized. Underlying a global need for more sustainable natural sources for treatment, the evidence supporting their chondroprotective potential is still building up. However, arriving at that kind of solution requires more clinical research, targeting the implications of long-term treatment, adverse effects, and epigenetic implications.

Dietary antioxidants, non-enzymatic antioxidant capacity and the risk of osteoarthritis in the Swedish National March Cohort

PURPOSE

Oxidative stress might play an important role in the development of osteoarthritis, but not much is known about the effect of antioxidants on osteoarthritis risk. We, therefore, aimed to investigate the effect of dietary vitamin C, E, beta-carotene, and non-enzymatic antioxidant capacity (NEAC), which measures overall antioxidant activity from the diet, on the risk of osteoarthritis.

METHODS

For this study 43,865 men and women from the Swedish National March Cohort (SNMC) were followed for up to 19 years. We computed dietary intake of vitamin C, E and beta-carotene using information from a Food Frequency Questionnaire (FFQ). To estimate dietary NEAC we combined the information from the FFQ with food item-specific antioxidant capacity values from an antioxidant food database. Cases of osteoarthritis were identified through the Swedish National Patient Registers. We categorized all exposure variables into sex-specific quartiles and used multivariable-adjusted Cox proportional hazards regression models to estimate hazard ratios (HRs) with 95% confidence intervals (95% CIs).

RESULTS

In total, we observed 5976 cases of OA during 469,148 person-years of follow-up. After adjusting for potential confounders, we did not find any association between vitamin C, beta-carotene and NEAC (p-values for trend > 0.5), but a positive association was found with higher dietary vitamin E intake (HR Q4 vs Q1: 1.11; 95% CI 1.02-1.21; p for trend = 0.01) and the risk of OA.

CONCLUSION

Our findings do not provide evidence for dietary antioxidants to protect from the development of OA, and a higher dietary vitamin E intake might even increase the risk.

Fruits

Fruits come in a wide variety of colors, shapes, and flavors. This chapter will cover selected fruits that are known to be healthy and highly nutritious. These fruits were chosen due to their common usage and availability. Since it is not possible to cover all health benefits or essential nutrients and important phytochemicals of the fruit composition, this chapter will focus on the key valuable constituents and their potential health effects.

Chondroprotective Properties of Human-Enriched Serum Following Polyphenol Extract Absorption: Results from an Exploratory Clinical Trial

Polyphenols are widely acknowledged for their health benefits, especially for the prevention of inflammatory and age-related diseases. We previously demonstrated that hydroxytyrosol (HT) and procyanidins (PCy), alone or in combination, drive preventive anti-osteoathritic effects in vivo. However, the lack of sufficient clinical evidences on the relationship between dietary phytochemicals and osteoarthritis remains. In this light, we investigated in humans the potential osteoarticular benefit of a grapeseed and olive extract (OPCO) characterized for its hydroxytyrosol (HT) and procyanidins (PCy) content. We first validated, in vitro, the anti-inflammatory and chondroprotective properties of the extract on primary cultured human articular chondrocytes stimulated by interleukin-1 beta (IL-1 β). The sparing effect involved a molecular mechanism dependent on the nuclear transcription factor-kappa B (NF-κB) pathway. To confirm the clinical relevance of such a nutritional strategy, we designed an innovative clinical approach taking into account the metabolites that are formed during the digestion process and that appear in circulation after the ingestion of the OPCO extract. Blood samples from volunteers were collected following ingestion, absorption, and metabolization of the extract and then were processed and applied on human primary chondrocyte cultures. This original ex vivo methodology confirmed at a clinical level the chondroprotective properties previously observed in vitro and in vivo.

The effect of pomegranate on oxidative stress parameters: A systematic review and meta-analysis

OBJECTIVE

Pomegranate contains remarkable amounts of phenolic ingredients and it has been related to the antioxidant capacity of this fruit. Several primary studies show that pomegranate intake can improve antioxidant status. The objective of this systematic review and meta-analysis consisted in investigating the effect of pomegranate on oxidative stress (OS) parameters.

METHODS

A comprehensive electronic database search in Scopus, Web of science, Embase, Cochrane library and Medline was performed to identify eligible randomized controlled trials (RCTs). A meta-analysis of included studies was performed on selected variables using a random-effects model. Quality assessment was conducted by means of Cochrane risk of bias assessment tool.

RESULTS

Systematic search yielded 575 references. A total of 11 RCTs reporting data from 484 participants included. Meta-analysis of data from 11 included RCTs did not support convincing evidence as to a significant increasing effect of pomegranate intake in TAC (SMD: 0.43 ; 95 %CI: -0.19, 1.06), Gpx (SMD: 0.18, 95 % CI: -0.25, 0.62, p = 0.4) and paraxonase (SMD: 0.36, 95 % CI: -0.50, 1.22, p= 0.41) as well as not significant decrease in Malondialdehyde (MDA) (SMD: -0.81, 95 % CI: -1.79, 0.09, P = 0.08).

CONCLUSION

Future well-designed clinical trials are needed before definite conclusive claims can be made about the effect of pomegranate on OS parameters.

The relationship between magnesium and osteoarthritis of knee: A MOOSE guided systematic review and meta-analysis

The impact of magnesium on risk of knee osteoarthritis (KOE) is still under investigation. This meta-analysis evaluated the relationship between magnesium and risk of KOE.A comprehensive search was performed to identify retrospective cohort study or cross-sectional study of the association between magnesium and KOE from the Cochrane library, PubMed, and Embase. The search time limit was from the establishment of the database to December 2018. Two evaluators selected the literature, extracted the data, and evaluated the quality of the literature according to the inclusion and exclusion criteria, independently. Meta-analysis was performed using RevMan 5.3 software and publication bias was assessed using Begg and Egger test and funnel plot.Finally, 6 studies were included with a total of 15,715 participants. Although higher daily intake of magnesium was associated with a significantly reduced risk of fracture in patients with KOE (OR = 0.66, 95%CI: 0.56, 0.78; P < .00001), it was not significant for lowering the risk of KOE (OR = 0.80; 95% CI: 0.61, 1.04; P = .1). Meta-analysis also showed that population with higher serum magnesium levels had significantly lower risk of KOE (odds ratio (OR) = 0.84; 95% confidence interval (CI): 0.72, 0.98; P = .03). Further subgroup analysis showed that the relationship between serum magnesium level and KOE risk was significantly affected by serum magnesium level (P = .006 for quartiles 4 vs 1).Higher level of magnesium intake was not associated with lower risk of KOE. However, higher daily intake of magnesium may be inversely associated with risk of fracture in KOE patients.

Relationship between oxidative balance score and quality of life in patients with osteoarthritis: Data from the Korea National Health and Nutrition Examination Survey (2014-2015)

Osteoarthritis (OA) has a multifactorial etiology that includes oxidative stress. Oxidative balance score (OBS) is a well-known indicator of oxidative stress. However, the association between OBS and OA has not been assessed. Thus, this study aimed to investigate the associations of OBS with OA and quality of life (QOL) in patients with OA.By using data from the Korea National Health and Nutrition Examination Survey VI, patients previously diagnosed and/or treated by a physician were considered to have OA regardless of the affected joints. The control group was defined as participants without any form of chronic arthritis. OBS was calculated by combining 10 pro-oxidant and antioxidant factors through a baseline nutritional and lifestyle assessment. Higher OBS scores indicated a predominance of antioxidant exposure. Multivariable logistic regression was used to estimate the adjusted odds ratios (ORs) for OA, and the EuroQoL five-dimensional questionnaire (EQ5D) was used in patients with OA after adjusting for demographic factors and comorbidities.Among the 14,930 participants, 296 patients with OA, and 1,309 controls were included in the analysis. In the age- and sex-adjusted model, the OR of the total OBS for OA was significant. In the full model adjusted for age, sex, education, income, and comorbidities, the total OBS for OA was not significant. Only the non-dietary pro-oxidant OBS had a significant inverse association with OA. The patients with OA who had a high EQ5D score had a higher total OBS than those with a low EQ5D score. The OR of the total OBS for a high EQ5D score was 1.14 in the multivariable logistic regression model. As we analyzed the OBS as a categorical variable (reference = Q1), the ORs of the Q2, Q3, and Q4 (highest) total OBS were 1.43, 2.71, and 2.22, respectively.In the fully adjusted model, the total OBS was not associated with OA. However, a positive association was observed between the total OBS and QOL in the patients with OA, indicating that antioxidative status was associated with better QOL in patients with OA.

A Review of the Science of Colorful, Plant-Based Food and Practical Strategies for "Eating the Rainbow"

Over the past decades, thousands of published studies have amassed supporting recommendations to consume fruits and vegetables for physiological and psychological health. Newer research has emerged to suggest that these plant-based foods contain a plethora of not only vitamins and minerals, but perhaps, most importantly, phytonutrients. These phytonutrients have known pleiotropic effects on cellular structure and function, ultimately resulting in the modulation of protein kinases and subsequent epigenetic modification in a manner that leads to improved outcomes. Even though eating fruits and vegetables is a well-known feature of a healthy dietary pattern, population intakes continue to be below federal recommendations. To encourage consumers to include fruits and vegetables into their diet, an “eat by color” approach is proposed in this review. Although each individual food may have numerous effects based on its constituents, the goal of this simplified approach was to identify general patterns of benefits based on the preponderance of scientific data and known mechanisms of food-based constituents. It is suggested that such a consumer-oriented categorization of these plant-based foods may lead to greater recognition of their importance in the daily diet throughout the lifespan. Other adjunctive strategies to heighten awareness of fruits and vegetables are discussed.

The Oxidative Stress in Knee Osteoarthritis Patients. An Attempt of Evaluation of Possible Compensatory Effects Occurring in the Disease Development

Background and Objective: Osteoarthritis (OA) is a disorder of the musculoskeletal system resulting in worsening of life condition. The research revealed the involvement of oxidative stress into both OA pathogenesis and the effects of therapeutic agents applied in OA cases. The activities of the most important antioxidant enzymes, namely superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and total antioxidant status (TAS), in blood of the knee OA patients were studied, with the aim of clarifying which enzymatic antioxidants are involved into osteoarthritis (OA)-related oxidative stress and whether any compensatory effects occur. The results were additionally analyzed with regard to gender. Methods: Whole blood SOD (U/mL), plasma GPx (U/L) and CAT (U/mL) activities as well as plasma TAS (mmol/L)) in knee OA patients were investigated. Sixty-seven patients (49 females and 18 males) with primary knee OA were enrolled. The control comprised 21 subjects (10 females and 11 males) free of osteoarthritis or inflammation. Results: TAS was decreased in OA subjects (4.39 ± 0.53 vs. 4.70 ± 0.60), with this effect being more significant in OA females (4.31 ± 0.51 vs. 5.02 ± 0.54). GPx was depressed in all OA patients (518 ± 176 vs. 675 ± 149). In both genders, GPx was decreased, significantly in males (482 ± 185 vs. 715 ± 105). SOD was decreased in all OA patients (109 ± 32 vs. 127 ± 42). CAT showed no difference in all OA subjects vs. control, while in OA females it was depleted (20.2 (11.6–31.6) vs. 38.5 (27.9–46.6)) and in OA men it increased (26.9 (23.3–46.5) vs. 14.0 (7.0–18.6)). Conclusions: The obtained results suggest that in men some compensatory mechanisms towards OA-related oxidative stress occurred. Based on the obtained data, the introduction of antioxidant supplements into OA therapy could be suggested with further research concerning the choice of agents.

Strawberries decrease circulating levels of tumor necrosis factor and lipid peroxides in obese adults with knee osteoarthritis

OBJECTIVE

Knee osteoarthritis (OA) is increasingly prevalent in obese people, who often have high cardio-metabolic risk factors. Among the few available non-surgical approaches, nutraceuticals have gained popularity, and dietary berries have mitigated arthritis symptoms in observational and animal studies. Clinical studies in OA are sparse, but recently we reported that strawberry supplementation can mitigate pain and reduce inflammatory markers in adults with knee OA. This study extends those observations.

METHODS

We conducted a randomized cross-over double-blind placebo-controlled trial on the effects of dietary freeze-dried strawberries on obesity-related hormones, biomarkers of inflammation and lipid peroxidation. Seventeen subjects (4 men, 13 women; age 57 ± 3 year) were randomized to strawberry supplements (50 g day-1 for 12 weeks) vs. placebo (50 g day-1, matched for calories and fiber), for two 12-week intervention periods, separated by 2-week washout phase.

RESULTS

Among 24 biomarkers of inflammation examined (Bioplex-Pro human inflammation panel), 12 were detectable in all samples. Among these, high-sensitivity TNF-α (hs-TNF-α) and the soluble tumor necrosis factor receptor (sTNF-R2) were significantly decreased after strawberry consumption (p < 0.05). There were no changes in other biomarkers of the TNF super family, such as APRIL and BAFF. Among serum biomarkers of oxidative stress, 4-hydroxy-2-nonenal (4-HNE) and conjugated dienes were also reduced (p < 0.05). No changes were observed in body weight, serum obesity-related hormones, or osteocalcin.

CONCLUSION

Strawberries lowered TNF-α, and lipid peroxidation products in obese adults with knee OA. Since, they also mitigate pain, these findings merit further investigation in larger trials.

PROMIS Physical and Emotional Health Scores Are Worse in Musculoskeletal Patients Presenting to Physiatrists than to Other Orthopedic Specialists

BACKGROUND

Physiatrists' unique training in person-centered biopsychosocial management of complex problems may influence musculoskeletal patients' expectations and self- and/or physician-referral patterns to physiatrists. Consequently, average patient complexity and need for multi-disciplinary services may be increased in physiatric patients.

OBJECTIVE

To compare musculoskeletal patients' self-reported physical and emotional health according to provider specialty. Researchers tested the null hypothesis that there is no significant difference in Patient-Reported Outcomes Measurement Information System (PROMIS) scores between patients who present to physiatrists in comparison to other musculoskeletal specialists.

DESIGN

Cross-sectional study.

SETTING

Orthopedic department of a tertiary academic medical center.

PATIENTS

Participants included 31 791 new adult patients (mean age 52.6 ± 16.2 years) who presented for initial elective evaluation of a musculoskeletal problem by an orthopedic surgeon or sports medicine trained emergency medicine, family medicine, pediatric, or physiatric physician.

METHODS

Patients completed the PROMIS computer adaptive test (CAT) Physical Function, Pain Interference, Anxiety, and Depression domains at department check-in prior to the physician encounter. Score differences by provider type were assessed using Wilcoxon rank-sum tests.

MAIN OUTCOME MEASUREMENTS

Mean PROMIS score in each domain subdivided by physiatric, surgical, and other nonsurgical provider type.

RESULTS

In total, 2081 patients presented to physiatrists, 28 267 presented to surgeons, and 1443 presented to other nonsurgical providers. For each respective provider type, average PROMIS scores were Physical Function 38.9 ± 8.2, 41.5 ± 9.5, and 43.5 ± 8.2; Pain Interference 62.6 ± 7.2, 60.9 ± 7.7, and 59.2 ± 6.8; Anxiety 54.5 ± 10.4, 51.9 ± 10.6, and 49.8 ± 9.8; and Depression 49.3 ± 10.4, 47.0 ± 10.0, and 44.2 ± 8.7. Physiatric patients had significantly worse average scores for all domains compared to surgical (P < .001) and other nonsurgical patients (P < .001).

CONCLUSIONS

Average PROMIS Physical Function, Pain Interference, Anxiety, and Depression scores were worse in musculoskeletal patients who presented to physiatrists in comparison to surgical or other nonsurgical providers. This suggests that some patients who choose to see or are referred to see physiatrists may have more or be more willing to endorse having biopsychosocial impairments.

LEVEL OF EVIDENCE

III.

Blueberries Improve Pain, Gait Performance, and Inflammation in Individuals with Symptomatic Knee Osteoarthritis

Osteoarthritis (OA) is the most common joint disorder in the world and is the most frequent cause of walking related disability among older adults in the US, which brings a significant economic burden and reduces quality of life. The initiation and development of OA typically involves degeneration or progressive loss of the structure and function of articular cartilage. Inflammation is one of the major drives of the progression of OA. Dietary polyphenols have been studied for their anti-inflammatory properties and potential anabolic effects on the cartilage cells. Blueberries are widely consumed and are high in dietary polyphenols, therefore regular consumption of blueberries may help improve OA. The purpose of the present study was to examine the effect of freeze dried whole blueberries on pain, gait performance, and inflammation in individuals with symptomatic knee OA. In a randomized, double-blind trial, adults age 45 to 79 with symptomatic knee OA, were randomized to either consume 40 g freeze-dried blueberry powder (n = 33) or placebo powder (n = 30) daily for four months. Blood draws and assessment of pain and gait were conducted at baseline, two months, and four months. Western Ontario McMaster Osteoarthritis Index (WOMAC) questionnaires were used to assess pain and GAITRite^® electronic walkway was used to evaluate gait spatiotemporal parameters. WOMAC total score and sub-groups, including pain, stiffness, and difficulty to perform daily activities decreased significantly in the blueberry treatment group (p < 0.05), but improvement of WOMAC total score and difficulty to perform daily activities were not observed in the placebo group. Normal walking pace single support percentage for both limbs increased (p = or < 0.007), while double support percentage for both limbs decreased in the blueberry treatment group (p = or < 0.003). No significant changes were observed in plasma concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-10, IL-13, matrix metalloproteinases (MMP)-3, MMP-13, and monocyte chemoattractant protein-1 (MCP-1) in both treatment groups. However, an increasing trend for IL-13 concentration and a decreasing trend in MCP-1 concentration were noted in the blueberry group. The findings of this study suggest that daily incorporation of whole blueberries may reduce pain, stiffness, and difficulty to perform daily activities, while improving gait performance, and would therefore improve quality of life in individuals with symptomatic knee OA.

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.

A systematic review and meta-analysis of nutrition interventions for chronic noncancer pain

BACKGROUND

This systematic review aimed to evaluate the impact of nutrition interventions on participant reported pain severity and intensity in populations with chronic pain.

METHODS

Eight databases were systematically searched for studies that included adult populations with a chronic pain condition, a nutrition intervention and a measure of pain. Where possible, data were pooled using meta-analysis. Seventy-one studies were included, with 23 being eligible for meta-analysis.

RESULTS

Studies were categorised into four groups: (i) altered overall diet with 12 of 16 studies finding a significant reduction in participant reported pain; (ii) altered specific nutrients with two of five studies reporting a significant reduction in participant reported pain; (iii) supplement-based interventions with 11 of 46 studies showing a significant reduction in pain; and (iv) fasting therapy with one of four studies reporting a significant reduction in pain. The meta-analysis found that, overall, nutrition interventions had a significant effect on pain reduction with studies testing an altered overall diet or just one nutrient having the greatest effect.

CONCLUSIONS

This review highlights the importance and effectiveness of nutrition interventions for people who experience chronic pain.

Dietary fruits and arthritis

Arthritis is a global health concern affecting a significant proportion of the population and associated with reduced quality of life. Among the different forms of arthritis, osteoarthritis (OA) and rheumatoid arthritis (RA) are the most common and lacking a definite cure in the affected individuals. Fruits, such as berries and pomegranates are rich sources of a variety of dietary bioactive compounds, especially the polyphenolic flavonoids that have been associated with antioxidant, anti-inflammatory and analgesic effects. Emerging research demonstrates a protective role of fruits and their polyphenols in pre-clinical, clinical and epidemiological studies of OA and RA. In this context, commonly available fruits, such as blueberries, raspberries and strawberries, and pomegranates have shown promising results in reducing pain and inflammation in experimental models and in human clinical studies of arthritis. There is also some evidence on the role of specific fruit polyphenols, such as quercetin and citrus flavonoids in alleviating RA symptoms. These emerging data deserve further investigation in rigorous scientific studies to determine the mechanisms, dosing and selection of fruits and fruit extracts in arthritis management.

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.

Inhibition of cartilage degradation and suppression of PGE2 and MMPs expression by pomegranate fruit extract in a model of posttraumatic osteoarthritis

OBJECTIVE

Osteoarthritis (OA) is characterized by cartilage degradation in the affected joints. Pomegranate fruit extract (PFE) inhibits cartilage degradation in vitro. The aim of this study was to determine whether oral consumption of PFE inhibits disease progression in rabbits with surgically induced OA.

METHODS

OA was surgically induced in the tibiofemoral joints of adult New Zealand White rabbits. In one group, animals were fed PFE in water for 8 wk postsurgery. In the second group, animals were fed PFE for 2 wk before surgery and for 8 wk postsurgery. Histologic assessment and scoring of the cartilage was per Osteoarthritis Research Society International guidelines. Gene expression and matrix metalloproteinases (MMP) activity were determined using quantitative reverse transcriptase polymerase chain reaction and fluorometric assay, respectively. Interleukin (IL)-1 β, MMP-13, IL-6, prostaglandin (PG)E₂, and type II collagen (COL2A1) levels in synovial fluid/plasma/culture media were quantified using enzyme-linked immunosorbent assay. Expression of active caspase-3 and poly (ADP-ribose) polymerase p85 was determined by immunohistochemistry. Effect of PFE and inhibitors of MMP-13, mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB was studied in IL-1 β-stimulated rabbit articular chondrocytes.

RESULTS

Safranin-O-staining and chondrocyte cluster formation was significantly reduced in the anterior cruciate ligament transaction plus PFE fed groups. Expression of MMP-3, MMP-9, and MMP-13 mRNA was higher in the cartilage of rabbits given water alone but was significantly lower in the animals fed PFE. PFE-fed rabbits had lower IL-6, MMP-13, and PGE₂ levels in the synovial fluid and plasma, respectively, and showed higher expression of aggrecan and COL2A1 mRNA. Significantly higher numbers of chondrocytes were positive for markers of apoptosis in the joints of rabbits with OA given water only compared with those in the PFE-fed groups. PFE pretreatment significantly reduced IL-1 β induced IL-6 and MMPs expression in rabbit articular chondrocytes. These effects were also mimicked using MMP-13, MAPK, and NF-κB inhibitors in IL-1 β-stimulated rabbit chondrocytes. In an in vitro activity assay, PFE blocked the activity of MMP-13. Like MAPK and NF-κB inhibitors, PFE was also effective in inhibiting IL-1 β-induced PGE₂ production in rabbit chondrocytes. PFE also reversed the inhibitory effect of IL-1β on COL2A1 mRNA and protein expression in IL-1 β-stimulated rabbit chondrocytes.

CONCLUSION

The present data highlight the chondroprotective effects of PFE oral consumption in a model of posttraumatic OA and suggest that PFE-derived compounds may have potential value in the management of OA.