Influence of Magnolol on the Secretion of α-Toxin by Staphylococcus aureus.

In this study we investigated the antimicrobial activity of magnolol on Staphylococcus aureus. The minimal inhibitory concentrations of magnolol against 31 S. aureus strains ranged from 4-32 μg/mL. In addition, hemolysin assays, Western blotting, and real-time RT-PCR were performed to investigate the effect of magnolol on α-toxin secretion by both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The results indicated that sub-inhibitory concentrations of magnolol dosedependently inhibited the transcription of hla (the gene encoding α-toxin) in S. aureus, resulting in a reduction of α-toxin secretion and, thus, hemolytic activities. [ABSTRACT FROM AUTHOR]