This study aimed to determine the effects of Xiebai Zengye decoction (XBZY) on airway
inflammation and respiratory function in rats with postinfectious
cough (PIC), and its regulatory effects on the
extracellular signal-regulated kinase (ERK) signaling pathway. Compared with the normal group, the rats from the PIC group had significantly shortened expiratory time (TE) and enhanced pause (EEP), increased resistance (RT), and enhanced pause (Penh), along with increased levels of serum
interleukin-4 (IL-4) and IL-6, and decreased levels of
IL-10. The lung and colon tissues of rats from the PIC group showed histopathological changes, including inflammatory cell infiltration, damaged mucosal epithelium, and crypt structure, with significantly increased ERK
mRNA and
protein expression levels. Treatment with XBZY and
montelukast sodium (MAS) improved the respiratory function and serum
cytokine levels, reduced tissue
inflammation, and decreased ERK
mRNA and
protein expression levels in the lung and colon tissues. In the lung tissues, XBZY treatment significantly decreased the expression of phosphorylated-ERK (p-ERK) protein, as well as p-MEK1/2, p-ERK1/2, and p-
c-Fos proteins, while in the colon tissues, XBZY significantly decreased the expression of p-ERK1/2 and p-
c-Fos proteins. However, MAS treatment only showed significant improvement in the lung tissue
inflammation score, and the expression level of p-ERK
protein in the lung tissue was decreased. In conclusion, the present study suggests that XBZY has a potential
therapeutic effect on PIC by improving respiratory function and attenuating
inflammation, and this effect may be associated with the inhibition of the ERK signaling pathway. These findings could provide a new direction for the development of treatments for PIC. However, further research is needed to elucidate the underlying molecular mechanisms of XBZY and to confirm its safety and efficacy in clinical trials.