AUTHOR=Arado Gustavo Marin , Amatto Pedro de Padua G. , Marins Mozart , Rizzi Elen Sanchez , França Suzelei de Castro , Coppede Juliana da Silva , Carmona Fábio , Pereira Ana Maria Soares 

TITLE=Anti-inflammatory and/or immunomodulatory activities of Uncaria tomentosa (cat’s claw) extracts: A systematic review and meta-analysis of in vivo studies

JOURNAL=Frontiers in Pharmacology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2024.1378408

DOI=10.3389/fphar.2024.1378408

ISSN=1663-9812

ABSTRACT=<sec><title>Background</title><p><italic>Uncaria tomentosa</italic> (Willd. ex Schult.) DC. (Rubiaceae) is traditionally used by Amazonian indigenous groups to treat inflammatory diseases. To date, there are no systematic reviews and meta-analyses on the use of <italic>U. tomentosa</italic> for inflammation control in animals supporting the traditional knowledge about this species. This study was conducted to evaluate the effect of <italic>U. tomentosa</italic> extracts in modulating inflammatory mediators and to determine which types of inflammatory diseases can be treated by this species.</p></sec><sec><title>Methods</title><p>We conducted a systematic review and meta-analysis of preclinical studies published before 26 July 2023, identified in PubMed, Embase, and Scopus. Four independent reviewers extracted the data and assessed the risks of bias. The effects of <italic>U. tomentosa</italic> on inflammatory diseases and the inflammatory mediators involved were extracted from the studies. Standardized mean differences (SMD) and 95% confidence intervals (95%CI) of the outcomes were estimated. The meta-analyses were conducted using RevMan 5.4 (Cochrane Collaboration). This protocol was registered in PROSPERO (CRD42023450869).</p></sec><sec><title>Results</title><p>Twenty-four of 523 studies were included. <italic>U. tomentosa</italic> extracts decreased the cytokines interleukin (IL)-6 (SMD: −0.72, 95%CI: −1.15, −0.29, <italic>p</italic> = 0.001) and transcription factor nuclear factor <italic>kappa</italic>-B (NF-κB) (SMD: −1.19, 95%CI: −1.89, −0.48, <italic>p</italic> = 0.001). However, the extracts did not significantly alter IL-1 (SMD: −0.16, 95%CI: −0.87, +0.56, <italic>p</italic> = 0.67), IL-10 (SMD: −0.05, 95%CI:–0.35, 0.45, <italic>p</italic> = 0.80), or tumor necrosis factor-<italic>alpha</italic> (TNF-α) levels (SMD: 0.18, 95%CI: −0.25, 0.62, <italic>p</italic> = 0.41).</p></sec><sec><title>Conclusion</title><p>Many extracts of stem bark, roots, and leaves of <italic>U. tomentosa</italic>, mostly aqueous and hydroethanolic, exhibited anti-inflammatory and/or immunomodulatory activities and low toxicity. The extracts decreased NF-κB and IL-6. These findings suggest that this species has the potential to treat inflammatory diseases in which these markers are increased, according to the ethnopharmacological use. These activities are not related to a specific class of compounds.</p></sec><sec><p><bold>Systematic Review Registration:</bold><ext-link ext-link-type="uri" xlink:href="https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=450869" xmlns:xlink="http://www.w3.org/1999/xlink">https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=450869</ext-link>, Identifier CRD42023450869.</p></sec>