Xuanfei Baidu granule alleviates coronavirus-induced pneumonia in low-temperature and high-humidity environments

Abstract

Objective: Our study aimed to investigate the action of Xuanfei Baidu granules (XFBD) and their mechanism of action in a model of coronavirus pneumonia under cold and damp conditions. Methods: A total of 60 Bagg Albino (BALB/c) mice were randomly assigned to different groups, including the control, model, low-dose XFBD (1.84 g/kg), medium-dose XFBD (3.67 g/kg), and high-dose XFBD (7.34 g/kg) groups. To simulate the model of coronavirus infection, a combination of cold and damp stimuli and coronavirus strain 229E (CoV 229E) was employed. Subsequently, XFBD was administered on the fifth day and lasted for 3 days. To evaluate the efficacy of XFBD in BALB/c mice, various parameters, including behavior, lung index, viral load, and pulmonary pathology, were observed. Levels of interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α) were measured using enzyme-linked immunosorbent assay (ELISA). The fractions of CD4+ T cells, CD8+ T cells, and B cells were measured using flow cytometry. Results: The mice in the control group were active, in good condition, and exhibited shiny hair. After modeling, the mice demonstrated less activity, low energy levels, messy and less shiny hair, poor appetite, and soft stools. The symptoms of coronavirus pneumonia were all significantly improved after the administration of different doses of XFBD. At three dosage levels, XFBD effectively increased gastrin (GAS) content, whereas medium and high doses of XFBD reduced motilin (MTL) content. The high-dose XFBD group showed a significant reduction in pathological damage to lung tissue. Treatment with three doses of XFBD demonstrated significant downregulation of inflammatory factors and regulation of CD4+ and CD8+ T cell and B cell expression. The high-dose XFBD group exhibited enhanced efficacy compared to the other doses. Conclusions: XFBD showed a therapeutic effect on coronavirus pneumonia under cold and damp conditions, improved the behavioral characterization and gastrointestinal index, and reduced the lung virus titer and histopathology. This may be associated with the inhibition of inflammation and an increase in the number of lymphocytes. Graphical abstract: http://links.lww.com/AHM/A61.