AUTHOR=Raeisi Hamideh , Azimirad Masoumeh , Abdemohamadi Elham , Pezzani Raffaele , Zali Mohammad Reza , Yadegar Abbas 

TITLE=Pleiotropic effects of Mentha longifolia L. extract on the regulation of genes involved in inflammation and apoptosis induced by Clostridioides difficile ribotype 001

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1273094

DOI=10.3389/fmicb.2023.1273094

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>The dramatic increase in multidrug-resistance of <italic>Clostridioides difficile</italic> isolates has led to the search for new complementary medicines against <italic>C. difficile</italic> infection (CDI). In this study, we aimed to examine the inhibitory effects of hydroethanolic extract of <italic>Mentha longifolia</italic> L. (ETOH-ML) on the growth of <italic>C. difficile</italic> RT001 and its toxigenic cell-free supernatant (Tox-S)-induced inflammation and apoptosis.</p></sec><sec><title>Methods</title><p>The active phytochemical components of ETOH-ML were detected using GC and HPLC. The antimicrobial properties of the extract were examined against <italic>C. difficile</italic> RT001. Furthermore, cell viability and cytotoxicity of Caco-2 and Vero cells treated with various concentrations of ETOH-ML, Tox-S of <italic>C. difficile</italic> RT001, and their combination were assessed. Anti-inflammatory and anti-apoptotic activities of ETOH-ML were explored in Tox-S stimulated Caco-2 cells using RT-qPCR.</p></sec><sec><title>Results</title><p>Based on our results, rosmarinic acid was the main phytochemical component of ETOH-ML. The extract showed significant antimicrobial activity against <italic>C. difficile</italic> RT001 by agar dilution and broth microdilution methods. Moreover, ETOH-ML at concentrations of &lt;25 μg/ml had no significant effect on cell viability compared to untreated cells. Treatment cells with the extract (10 or 25 μg/ml) significantly increased the cell viability and reduced the percentage of cell rounding in Caco-2 and Vero cells treated by Tox-S, respectively (<italic>P</italic> &lt; 0.0001). Co-treatment of Tox-S stimulated Caco-2 cells with ETOH-ML showed significant anti-inflammatory and anti-apoptotic activities by downregulating the gene expression level of IL-8, IL-1β, TNF-α, iNOS, TGF-β, NF-κB, Bax, and caspase-3, while upregulating the expression level of Bcl-2.</p></sec><sec><title>Discussion</title><p>Our results demonstrated for the first time the antimicrobial, anti-inflammatory, and anti-apoptotic effects of <italic>M. longifolia</italic> extract on <italic>C. difficile</italic> RT001 and its Tox-S. However, further research is needed to evaluate the potential application of <italic>M. longifolia</italic> extract on CDI treatment in clinical setting.</p></sec>