Efficacy of Ambroxol Combined with Loquat Syrup on Bacterial Pneumonia in Mice

PURPOSE: Bacterial pneumonia is a prevalent respiratory disease and a primary cause of death among hospitalized patients. Ambroxol and loquat syrup are widely utilized pharmaceuticals for managing respiratory infections in China. This study investigates the potential application and efficacy of combining ambroxol with loquat syrup for treating bacterial pneumonia. METHODS: In this study, mice with P. aeruginosa-induced bacterial pneumonia were used to evaluate the therapeutic effects of ambroxol, loquat syrup, and their combination. A bacterial plate coating assay was performed to measure the P. aeruginosa content in saliva, lung tissue, and bronchoalveolar lavage fluid (BALF). A plate colony counting assay was conducted to assess the antibacterial activity of ambroxol and loquat syrup. Serum, BALF, and lung tissues were analyzed using qPCR, ELISA, immunohistochemistry, and hematoxylin-eosin staining to evaluate disease severity. RESULTS: In this study, the experimental results demonstrate that, compared to treatment with ambroxol and/or loquat syrup alone, the combined administration of ambroxol and loquat syrup significantly increases the volume of saliva expectorated by mice infected with bacteria, concurrently augmenting bacterial presence in saliva while diminishing bacterial burden in the lungs, with significant differences observed (p