Liquiritigenin prevents Staphylococcus aureus-mediated lung cell injury via inhibiting the production of α-hemolysin

Abstract

Staphylococcus aureus is a significant Gram-positive bacterium that is associated with a broad spectrum of diseases ranging from minor skin infections to lethal pneumonia, endocarditis, and toxinoses. α-Hemolysin is one of the most important exotoxins that contribute to the pathogenesis of S. aureus infections. Liquiritigenin is one of the most significant active components in licorice. In this study, hemolysis, western blot, and real-time reverse transcription-PCR assays were performed to investigate the impact of liquiritigenin on the production of S. aureus α-hemolysin. The results showed that low concentrations of liquiritigenin remarkably decreased S. aureus α-hemolysin production in a dose-dependent manner. Using live/dead cell staining and lactate dehydrogenase assays, we found that liquiritigenin could protect human lung cells (A549) from α-hemolysin-mediated injury. The data indicated that this compound could potentially be useful in developing drugs aiming at staphylococcal α-hemolysin.

Keywords:

• Staphylococcus aureus
• liquiritigenin
• α-hemolysin

Acknowledgments

We thank Professor Timothy J. Foster (Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin, Ireland) for kindly providing S. aureus strains 8325-4 and DU 1090. This work was supported by the National Nature Science Foundation of China (No. 31130053).