Effectiveness of Curcuma longa extract versus placebo for the treatment of knee osteoarthritis: A systematic review and meta-analysis of randomized controlled trials

Inflammation as a therapeutic target for osteoarthritis: A literature review of clinical trials

The burden of osteoarthritis (OA) is rapidly increasing with population aging, but there are still no approved disease-modifying drugs available. Accumulating evidence has shown that OA is a heterogeneous disease with multiple phenotypes, and it is unlikely to respond to one-size-fits-all treatments. Inflammation is recognized as an important phenotype of OA and is associated with worse pain and joint deterioration. Therefore, it is believed that anti-inflammatory treatments may be more effective for OA with an inflammatory phenotype. In this review, we summarized clinical trials that evaluated anti-inflammatory treatments for OA and discussed whether these treatments are more effective in inflammatory OA phenotypes compared to general OA patients.

The efficacy of curcumin in relieving osteoarthritis: A meta-analysis of meta-analyses

Osteoarthritis (OA) is one of the most prevalent degenerative joint diseases. Several meta-analyses have shown that curcumin could improve the function of the knee and alleviate pain in OA, while some meta-analyses demonstrate controversial results. Hence, we assessed curcumin's effects on knee OA in an umbrella meta-analysis. PubMed, Scopus, Embase, and Web of Science databases were employed to find English-language meta-analyses of randomized controlled trials investigating the effect of curcumin supplementation on OA outcomes up to September 2023. The visual analog scale (VAS), Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain, function, and stiffness scales were analyzed. Effect sizes and 95% confidence intervals were utilized to obtain the overall effect size. A random-effects model was applied to perform the meta-analysis. Heterogeneity was determined by I2 statistics and the Cochrane Q-test. The pooled effect of the 11 included meta-analyses showed that curcumin could significantly decrease the VAS score (weighted mean difference [WMD] and standardized mean difference [SMD]), WOMAC-total (SMD and WMD), WOMAC-Function (SMD and WMD), WOMAC-Pain (SMD), and WOMAC-Stiffness scores (SMD) (p ≤ 0.001, ≤0.001, ≤0.001, 0.007, ≤0.001, 0.002, ≤0.001, ≤0.001, respectively). The results strongly support curcuminoid supplementation in relieving pain, improving joint mobility and stiffness, and shortening medication usage of OA patients.

Natural products in osteoarthritis treatment: bridging basic research to clinical applications

Osteoarthritis (OA) is the most prevalent degenerative musculoskeletal disease, severely impacting the function of patients and potentially leading to disability, especially among the elderly population. Natural products (NPs), obtained from components or metabolites of plants, animals, microorganisms etc., have gained significant attention as important conservative treatments for various diseases. Recently, NPs have been well studied in preclinical and clinical researches, showing promising potential in the treatment of OA. In this review, we summed up the main signaling pathways affected by NPs in OA treatment, including NF-κB, MAPKs, PI3K/AKT, SIRT1, and other pathways, which are related to inflammation, anabolism and catabolism, and cell death. In addition, we described the therapeutic effects of NPs in different OA animal models and the current clinical studies in OA patients. At last, we discussed the potential research directions including in-depth analysis of the mechanisms and new application strategies of NPs for the OA treatment, so as to promote the basic research and clinical transformation in the future. We hope that this review may allow us to get a better understanding about the potential bioeffects and mechanisms of NPs in OA therapy, and ultimately improve the effectiveness of NPs-based clinical conservative treatment for OA patients.

Prevention and treatment of inflammatory arthritis with traditional Chinese medicine: Underlying mechanisms based on cell and molecular targets

Inflammatory arthritis, primarily including rheumatoid arthritis, osteoarthritis and ankylosing spondylitis, is a group of chronic inflammatory diseases, whose general feature is joint dysfunction with chronic pain and eventually causes disability in older people. To date, both Western medicine and traditional Chinese medicine (TCM) have developed a variety of therapeutic methods for inflammatory arthritis and achieved excellent results. But there is still a long way to totally cure these diseases. TCM has been used to treat various joint diseases for thousands of years in Asia. In this review, we summarize clinical efficacies of TCM in inflammatory arthritis treatment after reviewing the results demonstrated in meta-analyses, systematic reviews, and clinical trials. We pioneered taking inflammatory arthritis-related cell targets of TCM as the entry point and further elaborated the molecular targets inside the cells of TCM, especially the signaling pathways. In addition, we also briefly discussed the relationship between gut microbiota and TCM and described the role of drug delivery systems for using TCM more accurately and safely. We provide updated and comprehensive insights into the clinical application of TCM for inflammatory arthritis treatment. We hope this review can guide and inspire researchers to further explore mechanisms of the anti-arthritis activity of TCM and make a great leap forward in comprehending the science of TCM.

The effects of antioxidants on knee osteoarthritis: A systematic review and meta-analysis

Objective

Knee osteoarthritis (KOA) is one of the growing health problems with a considerable burden. With recent research on the possible effectiveness of antioxidants in the remission of KOA symptoms, a systematic review and meta-analysis was required to confirm this hypothesis.

Design

Literature studies were searched on the most comprehensive databases such as PubMed, International Scientific Indexing, and Scopus, with no language and time restrictions. On 17 July 2021, a search strategy was developed based on the roots of "osteoarthritis (OA)" and "antioxidants," with no time or language limitations. As the primary outcome, pain was evaluated based on all indicators for evaluating pain [e.g., Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain scores, the visual analog scale (VAS), and the numerical rating scale (NRS)]. The symptoms and functions of KOA and quality of life (QOL) were also considered as secondary outcomes, each of which was measured and reported by the corresponding instrument in the studies. To measure the changes in pain, symptoms, and functions of participants, we included randomized controlled trials with a placebo control or other medical therapeutic interventions. Publication bias was assessed using Begg's funnel plot and Egger's regression test, which was deemed to be statistically significant at 0.1, and the results were checked by the trim-and-fill test.

Results

After refinement, data were extracted from 31 documents from 7,698 primary searched papers. Using the VAS as a reliable psychometric measuring instrument, the present study revealed that a significant difference in the characteristics of disease-related symptoms of patients with KOA was reached after antioxidant therapy (standardized mean difference (SMD): 0.467, 95% confidence interval (CI): 0.303-0.632, p < 0.0001). The results reported by WOMAC confirmed no significant difference in the combined score, difficulty score, pain score, and stiffness score.

Conclusion

As the first comprehensive systematic review of the association between antioxidant supplementation and KOA, this study showed that antioxidants can decrease disease-related symptoms in patients with KOA. The results can be useful for health policy decisions and future related studies.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022351060, identifier: CRD42022351060.

Trends and frontiers in natural products for arthritis, 2000-2021: A bibliometric analysis

BACKGROUND

Arthritis has become one of the trouble diseases that upsets people. A growing number of studies have shown that natural products have great potential for the treatment of arthritis. However, few bibliometrics have been systematically studied in this area. This paper analyzes the literature data of natural products on the arthritis research, and the research hot spots and future research directions of the treatment of arthritis by natural products were explored.

METHOD

Through CiteSpace, VOSviewer software and Bibliometricx under the R language environment, the article and review literatures on the treatment of arthritis with natural drugs in the Web of Science core collection database were analyzed by bibliometric analysis.

RESULTS

On December 28, 2021, a total of 2102 records were retrieved, 81.69% publications were issued in 2012 to 2021, mainly in China-dominated Asian countries, with cooperation among countries. The analysis of the number of articles published by institutions shows that the number of articles published by China Academy of Chinese Medical Sciences is up to 82. Lu, Aiping and Smolen, JS are the authors with the highest citation frequency and co-citation frequency. Keywords analysis showed that the research of natural drugs mainly focused on gene expression, anti-inflammatory and other mechanisms and signaling pathways. With the progress of science and technology and the integration of multi-disciplines, the research on natural drugs for arthritis will be more in-depth and specific.

CONCLUSION

In this study, literature metrology analysis was conducted on natural products in the treatment of arthritis, in order to grasp the background, trends and frontiers of the research, and predict possible research hotspots in the future. It is expected to provide some reference value and direction for future scholars in this field.

Zingiberaceae plants/curcumin consumption and multiple health outcomes: An umbrella review of systematic reviews and meta-analyses of randomized controlled trials in humans

This umbrella review is to recapitulate and grade the available evidence of associations between consumption of Zingiberaceae plants/curcumin (Cur) and multiple health-related outcomes. This study included 161 meta-analyses of randomized controlled trials in 76 articles with 67 unique health outcomes. Data on heterogeneity and publication bias are considered to assess the quality of evidence. Based on the different impact of Zingiberaceae plants/Cur on human health, the advantages outweigh the disadvantages. Zingiberaceae plants/Cur can mainly improve metabolic syndrome, non-alcoholic fatty liver disease, cardiovascular disease, and some chronic inflammatory diseases, likewise, obviously relief the pain of osteoarthritis and related diseases. Ginger supplements have been shown to improve vomiting during pregnancy and to relieve nausea and vomiting caused by chemotherapy and surgery. The surgery is any type of surgery, including laparoscopic surgery, gynecological surgery and mixed surgery. Beneficial associations were found with Cur intervention in gastrointestinal, neurological and oral diseases. Zingiberaceae plants/Cur are generally safe and favorable for multiple health outcomes in humans. High-quality research is further needed to prove the observed associations.

Quality of Evidence Supporting the Role of Curcuma Longa Extract/Curcumin for the Treatment of Osteoarthritis: An Overview of Systematic Reviews

Background

Well known for its good anti-inflammatory effect, curcuma longa extract (CLE)/curcumin (C) has a potential effect on osteoarthritis (OA), and a large number of researchers have completed several systematic reviews/meta-analyses (SRs/MAs) in this research area. However, the methodological and evidentiary quality of these SRs/MAs need to be further evaluated, and whether these findings provide reliable evidence for clinicians remains controversial.

Methods

Two researchers collected data from seven databases for SRs/MAs that are about randomized controlled trials (RCTs) on CLE/C for OA. Assessment was made for the SRs/MAs included in this article by means of the Assessment System for Evaluating Methodological Quality 2 (AMSTAR-2), the Risk of Bias in Systematic (ROBIS) scale, the list of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

Results

Nine published SRs/MAs were included in our study. According to the results of the AMSTAR-2 assessment, only one SR/MA was assessed as high quality. According to the ROBIS evaluation results, only 2 SRs/MAs have a low risk of bias. According to the results of the PRISMA checklist assessment, only 2 SRs/MAs studies fully reported the checklist, while other studies had reporting flaws. According to GRADE, a total of 59 effect sizes extracted from the included SRs/MAs were evaluated, among which no effect size was rated as high.

Conclusions

CLE/C may be an effective and safe complementary treatment for OA. However, further standard SRs/MAs and RCTs are needed to provide an evidence-based medical rationale for this.

The comparison of curcuminoid formulations or its combination with conventional therapies versus conventional therapies alone for knee osteoarthritis

BACKGROUND

Presently, curcuminoid formulations or its combination with conventional therapies has been used for the treatment of knee osteoarthritis (KOA). Nevertheless, evidence is limited due to small-sized clinical trials. This study aims to evaluate the efficacy of curcuminoid formulations or its combination with conventional therapies for KOA.

METHODS

Randomized controlled trials comparing curcuminoid formulations or its combination with conventional therapies versus conventional therapies, such as non-steroidal antiinflammatory drugs (NSAIDs) and chondroitin sulfate/glucosamine, were searched from databases.

RESULTS

In total, 14 studies involving 1533 patients were included. Curcuminoid formulations were comparative to NSAIDs in reducing Visual Analogue Scale (VAS), total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and WOMAC score for pain/stiffness/physical function. No significant difference was seen between the two groups in terms of patients' satisfaction index, patients' global assessment, reduction of several inflammatory factor, rate of drug compliance, and rescue medication. Notably, curcuminoid formulations combined with NSAIDs significantly reduced VAS and WOMAC/Knee injury and OA Outcome Score (KOOS) pain score more than NSAIDs did. In addition, the curcuminoid formulations were superior to chondroitin sulfate/glucosamine in reducing VAS, total WOMAC score, and WOMAC score for stiffness/difficulty in physical function, while no significant difference was seen in reducing WOMAC pain score and Karnofsky Performance Scale score.

CONCLUSIONS

Curcuminoid formulations may be considered a promising alternative for treating KOA. Key points • Curcuminoid formulations are comparative to NSAIDs for KOA. • Curcuminoid formulations are superior to chondroitin sulfate/glucosamine for KOA. • Curcuminoid formulations could provide additional benefits in alleviating pain and some adverse events caused by NSAIDs.