Yinhuapinggan granule ameliorates lung injury caused by multidrug-resistant Acinetobacter baumannii via inhibiting NF-κB/NLRP3 pathway

Yinhuapinggan granule (YHPG) is a traditional Chinese medicine prescription with rich clinical experience for the treatment of colds and coughs. The aim of this study is to investigate the protective effect of YHPG on multidrug-resistant (MDR) Acinetobacter baumannii (A. baumannii) infection in vivo and its potential anti-inflammatory mechanism. BALB/c mice were intranasally inoculated with MDR A. baumannii strain to establish the pneumonia infection model, and received intraperitoneally cyclophosphamide to form immunosuppression before attack. YHPG (6, 12 and 18 g/kg) was administered by gavage once a day for 3 consecutive days after infection. The protective effect of YHPG was evaluated by lung index, spleen index, thymus index, pathological changes of lung tissue and inflammatory factors (IL-1β, IL-6 and TNF-α) in serum. The expression of key targets of NF-κB/NLRP3 signaling pathway in vivo was analyzed by immunohistochemistry, immunofluorescence, reverse transcription quantitative PCR (RT-qPCR) and Western blot. The results showed that YHPG improved the lung index and its inhibition rate, immune organ indexes and lung pathological changes in infected mice, and significantly reduced IL-1β, IL-6 and TNF-α levels in serum. In addition, YHPG significantly down-regulated the mRNA and protein expression of NF-κB p65, NLRP3, ASC, Caspase-1, TNF-α, IL-6 and IL-1β in mice lung tissue. The results of the current study demonstrated that YHPG has significant protective effects on mice infected with MDR A.baumannii, which may be related to the regulation of inflammatory factors and NF-κB/NLRP3 signaling pathway, indicating that YHPG has a wide range of clinical application value and provides a theoretical basis for its treatment of MDR A.baumannii infection.