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Subinhibitory concentrations of punicalagin reduces expression of virulence-related exoproteins by Staphylococcus

Su-Hyun Mun1, Ryong Kong2, Yun-Soo Seo1

  • 1Department of Oriental Pharmacy, College of Pharmacy, Wonkwang Oriental Medicines Research Institute, Institute of Biotechnology, Wonkwang University, Iksan, Jeonbuk 570-749, Korea.

FEMS Microbiology Letters
|December 16, 2016
PubMed

Insights

Punicalagin, a natural compound, effectively reduces the secretion of key Staphylococcus aureus toxins like alpha-toxin and enterotoxins. This suggests its potential as a therapeutic agent against S. aureus infections.

Area of Science:

  • Microbiology
  • Pharmacology
  • Molecular Biology

Background:

  • Staphylococcus aureus is a significant pathogen.
  • It produces numerous virulence factors, including toxins like alpha-toxin, enterotoxins (SEA, SEB), and toxic shock syndrome toxin.
  • These toxins contribute to S. aureus pathogenicity.

Purpose of the Study:

  • To investigate the effect of punicalagin on the secretion of Staphylococcus aureus exoproteins.
  • To determine if punicalagin influences the production of alpha-toxin, SEA, and SEB.
  • To explore the mechanism by which punicalagin affects toxin production.

Main Methods:

  • Western blotting to detect alpha-toxin, SEA, and SEB.
  • Tumor necrosis factor (TNF) release assay to assess culture supernatant activity.
  • Quantitative RT-PCR to measure the transcriptional level of the agr gene.

Main Results:

  • Punicalagin significantly reduced the production of alpha-toxin, SEA, and SEB in methicillin-resistant S. aureus in a dose-dependent manner.
  • Punicalagin decreased the TNF-inducing activity of S. aureus culture supernatants.
  • Punicalagin inhibited the transcription of the agr gene, suggesting a mechanism for reduced exotoxin secretion.

Conclusions:

  • Punicalagin effectively inhibits the expression of alpha-toxin and enterotoxins in S. aureus.
  • The inhibition appears to be mediated by reduced transcription of the agr gene.
  • Punicalagin shows promise as a potential therapeutic agent for treating toxigenic staphylococcal diseases.
Keywords:
enterotoxinmethicillin-resistant Staphylococcus aureus, punicalagintumor necrosis factorα-toxin

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