Unique synergistic antiviral effects of Shufeng Jiedu Capsule and oseltamivir in influenza A viral-induced acute exacerbation of chronic obstructive pulmonary disease

The aim of the present study was to investigate the synergistic effects and interactive mechanisms of Shufeng Jiedu Capsule (SFJDC) combined with oseltamivir in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) induced by the influenza A virus (IAV). The extraction of SFJDC was analyzed by UHPLC/ESI Q-Orbitrap Mass Spectrometry. Human bronchial epithelial cells were isolated from COPD (DHBE) bronchial tissues, co-cultured with IAV for 24 h, and were subsequently treated with SFJDC and/or oseltamivir. Cell viability was detected by MTT assay. A rat model of COPD with IAV infection was established and treated with SFJDC and/or oseltamivir. Interleukin (IL)-1β and IL-18 in serum and bronchoalveolar lavage fluid (BALF) were measured by ELISA. Additionally, mRNA and protein levels of NLRP3 inflammasome pathway were measured by quantitative real-time PCR and Western blotting, respectively. SFJDC and/or oseltamivir, at their optimal concentrations, had no significant cytotoxicity against DHBEs. The levels of NLRP3-inflammasome-associated components were significantly elevated after cells were inoculated with IAV, whereas the mRNA and protein levels of these components were significantly decreased after treatment with SFJDC and/or oseltamivir in vitro. Moreover, in vivo, the combination of SFJDC and oseltamivir improved survival rates, attenuated clinical symptoms, induced weight gain, alleviated lung damage, and significantly reduced IL-1β and IL-18 levels in serum and BALF, as well as reduced the expression levels of NLRP3-associated components and viral titers in lung homogenates. SFJDC combined with oseltamivir treatment significantly attenuated IAV-induced airway inflammation and lung viral titers. Hence, our findings may provide a novel therapeutic strategy for IAV-induced respiratory infection.