Astragaloside IV Inhibits Salmonella‑Induced Meningitis Via Modulation of Bacterial Virulence and Host Response

Abstract

Objectives: To control Salmonella‑induced meningitis, in this study, we aimed to investigate the potential anti‑virulence activity and neuroprotective role of astragaloside IV (AS‑IV) under in vitro and ex vivo conditions during coculturing with Salmonella cells.Materials and Methods: The expression of virulence factors encoding genes was tested under in vitro conditions using quantitative real‑time polymerase chain reaction (PCR) and Western blot analysis. In addition, Salmonella cells and neuron cells were cocultured to examine the expression of virulence‑associated genes and host immune response.Results: The results of this study indicate that AS‑IV efficiently inhibited the production of virulence factors such as biofilm formation and expression of virulence‑associated genes including rpoS, phoP, sopA, and spvB under both in vitro and ex vivo conditions. In addition, our results showed that AS‑IV might boost the production of reactive oxygen species via Nrf2/ARE signaling pathway, which in turn inhibits the growth and virulence factors of Salmonella cells.Conclusion: In summary, the results of this study provide insights into the mechanisms of AS‑IV against Salmonella infections, and we identified a promising therapeutic agent against Salmonella‑induced meningitis.

Keywords: Astragaloside IV; meningitis; Nrf2/ARE; salmonella cells; virulence