Abstract: AIM: To study the effect of oral lienal polypeptide on cough and inflammation in mice, in order to expand the clinical application of immune modulator lienal polypeptide and provide a new strategy for relieving cough and inflammation.  METHODS: The cough model of mice was induced by concentrated ammonia. The cough frequency and tolerance latency of mice within 6 minutes were recorded every day. The histopathological changes of spleen and lung were evaluated by HE staining and spleen index. TNF-α, IL-1β and IL-6 levels in spleen and lung of mice was detected by ELISA. RESULTS: Oral administration of spleen polypeptide could prolong the tolerance latency of mice to concentrated ammonia to a certain extent and significantly reduce the cough frequency of mice. HE staining showed that oral spleen polypeptide could significantly reduce the alveolar surface area and improve lung expansion in mice. The results of ELISA showed that oral spleen polypeptide decreased the levels of some proinflammatory factors in spleen and lung. CONCLUSION: Lienal polypeptide can alleviate cough and emphysema like symptoms induced by ammonia, improve immune ability and inflammation in mice.

Key words: lienal peptides, ammonia-caused cough, emphysema, inflammation