Geniposide attenuates Staphylococcus aureus-induced pneumonia in mice by inhibiting NF-κB activation.

Staphylococcus aureus (S. aureus) is a major cause of pneumonia that often affects young and immunocompetent patients. Inflammation plays an important role in the development of S. aureus-induced pneumonia. Geniposide, a major iridoid glucoside component of gardenia fruit, has been reported to have anti-inflammatory and anti-oxidative effects. The purpose of this study was to investigate the protective effects of geniposide on S. aureus-induced pneumonia in mice. Lung histopathological changes were detected by hematoxylin-eosin (H&E) staining. Lung myeloperoxidase (MPO) activity, wet-to-dry (W/D) ratio, and inflammatory cytokine levels in bronchoalveolar lavage fluid (BALF) were measured. The results showed that S. aureus-induced lung histopathological changes were attenuated by geniposide. S. aureus-induced MPO activity and lung W/D ratio were inhibited by treatment of geniposide. Furthermore, the levels of TNF-α and IL-1β in the BALF were also suppressed by geniposide. In addition, geniposide significantly inhibited S. aureus-induced nuclear factor kappa B (NF-κB) activation. Taken together, these results showed that geniposide inhibited S. aureus-induced pneumonia in mice by inhibiting NF-κB signaling pathway. Geniposide might be used as a potential agent for the treatment of S. aureus-induced pneumonia.