Astragaloside iv inhibits salmonella-induced meningitis via modulation of bacterial virulence and host response

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.