Diosmetin inhibits the expression of alpha-hemolysin in Staphylococcus aureus
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Staphylococcus aureus is a significant human pathogen that causes a wide range of diseases. Alpha-hemolysin (Hla), a pore-forming cytotoxin that is produced by most S. aureus strains, can cause tissue injury and plays a critical role in the virulence of this pathogen. In the present study, we discovered that diosmetin, a natural flavonoid that occurs primarily in citrus fruits and exhibits little anti-S. aureus activity, could diminish the production of Hla in culture supernatants in a concentration-dependent manner. The analysis of cytotoxicity in the co-culture system of S. aureus and A549 epithelial cells showed that such inhibition confers significant protection against S. aureus-mediated injury. Our results suggested that diosmetin has the potential to be a new anti-virulence drug for S. aureus infection, particularly for the targeting of Hla.
KeywordsStaphylococcus aureus Diosmetin Alpha-hemolysin Anti-virulence
We thank Timothy J. Foster (Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin, Ireland) for kindly providing strain 8325-4. This work was supported by the National Basic Research Program of China (Grant 2013CB127205), the National Nature Science Foundation of China (grant 31130053) and the National 863 program (grant 2012AA020303).
Conflict of interest
The authors declare no conflict of interest.
The defibrinated rabbit blood was commercially obtained from Zheng Zhou Jiu Long Biological Products Co Ltd and no animals were directly used in the experiments above.
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