Subinhibitory concentrations of pinocembrin exert anti-Staphylococcus aureus activity by reducing alpha -toxin expression.

摘要

Aims: Natural products have been used as potentially important sources of novel antibacterials in combating pathogenic Staphylococcus aureus isolates, a major problem around the world. In this study, we aimed to investigate the antibacterial effects of pinocembrin (PNCB) against Staph. aureus pneumonia in a murine model and its influence on the production of Staph. aureus alpha -haemolysin (Hla). Methods and Results: The in vitro activities of PNCB on alpha -haemolysin production were determined using haemolysis, Western blot and real-time RT-PCR assays. The viability and cytotoxicity assays were performed to evaluate the influence of PNCB on alpha -toxin-mediated injury of human alveolar epithelial cells. Moreover, through histopathologic analysis, we further determined the in vivo effects of PNCB on Staph. aureus pneumonia in a mouse model. In vitro, PNCB at low concentrations exhibited inhibitory activity against alpha -haemolysin production and attenuated alpha -haemolysin-mediated cell injury. Furthermore, the in vivo findings demonstrated that PNCB protected mice from Staph. aureus pneumonia. Conclusions: We have provided new evidence of the effects of PNCB, which suggest that PNCB attenuated alpha -haemolysin-mediated cell injury and protected mice from Staph. aureus pneumonia. Significance and Impact of the Study: The findings indicate that PNCB may be used as a basis for anti-Staphylococcus agent.