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Journal of Medical Microbiology logo Journal of Medical Microbiology

Volume 75, Issue 2

Regulation of virulence factors of by , and antimicrobial peptide LL-37 Open Access

Abstract

The increasing resistance and the pathogen’s complex multi-drug resistance mechanisms made the selection of effective antimicrobial treatments more challenging for (). The study aimed to explore the effect of , and antimicrobial peptide LL-37 on the virulence factors of .

Previous studies have shown that extracts from traditional Chinese medicines, and , can also enhance the effects of antibiotics and reduce antibiotic resistance in . Antimicrobial peptide LL-37 shows the potential as a new-generation candidate for treating multi-drug-resistant bacteria, which has advantages over traditional antibiotics, whilst the combination role between , and LL-37 in remains unknown.

We explored whether the combined use of , and LL-37 can exert antibacterial effects through the quorum sensing (QS) system.

The minimal inhibitory concentrations of , and LL-37 were determined for and using micro broth dilution. The antibacterial activity of combined with LL-37 and combined with LL-37 was also assessed. The growth abilities of were analysed after being treated with , and LL-37, respectively. Elastase secretion was measured using Congo red-elastic proteinase assays. And the expressions of QS genes (, ) were analysed by real-time PCR.

Single or combined treatments of and LL-37 and and LL-37 would significantly reduce elastase secretion. There were no significant differences in proliferation between the groups at any timepoint. All treatments downregulated and gene expressions.

, and antimicrobial peptide LL-37 all down-regulate the QS system-related genes of , inhibiting the secretion of virulence factors and reducing bacterial toxicity.

  • Received:
  • Accepted:
  • Published Online:
Keyword(s): antimicrobial peptide LL-37 , Prunella vulgaris , Pseudomonas aeruginosa , Scutellaria baicalensis and virulence factors
Funding
This study was supported by the:
  • the Guangdong Provincial Key Laboratory of Research on Emergency in TCM, China (Award 2023B1212060062)
    • Principal Award Recipient: QianXiao
  • the Guangzhou Basic and Applied Foundation, China (Award 2023A03J0225)
    • Principal Award Recipient: QianXiao
  • the Guangdong Hospital of Traditional Chinese Medicine, China (Award YN2022QN09)
    • Principal Award Recipient: QianXiao
© 2026 The Authors
  • This is an open-access article distributed under the terms of the Creative Commons Attribution License.
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2026-02-04
2026-02-09

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Regulation of virulence factors of Pseudomonas aeruginosa by Scutellaria baicalensis, Prunella vulgaris and antimicrobial peptide LL-37
J. Med. Microbiol. 75, 002122 (2026); https://doi.org/10.1099/jmm.0.002122
/content/journal/jmm/10.1099/jmm.0.002122
/content/journal/jmm/10.1099/jmm.0.002122
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