Abstract: A cough hypersensitivity mouse model was established by continuous 14-day cigarette smoke exposure.Concurrently,mice were intragastrically administered with medium-dose (0.8 g/kg) and high-dose (1.6 g/kg) of volatile oil from Alpinia japonica rhizome and a positive drug.The body weight changes of the mice were recorded daily.On the 15th day,cough was triggered by citric acid in the mice,and the cough latency and the number of coughs within 3 minutes were recorded.The pathological changes of the mouse lung tissue were evaluated by hematoxylin-eosin staining,and the inflammatory score was determined.The cough-suppressing effect of low,medium,and high doses of volatile oil from Alpinia japonica rhizome (0.4,0.8,1.6 g/kg) was examined through the mouse phenol red tracheal secretion experiment.The results showed that volatile oil from Alpinia japonica rhizome could antagonize the weight loss in mice caused by cigarette smoke modeling to a certain extent;the high-dose of volatile oil from Alpinia japonica rhizome could effectively reduce the number of coughs in mice,prolong the cough latency;the medium and high-dose of volatile oil from Alpinia japonica rhizome could significantly improve the inflammation of mouse lung tissue;the medium and high-dose of volatile oil from Alpinia japonica rhizome could effectively increase the phenol red secretion in the mouse trachea.This suggests that volatile oil from Alpinia japonica rhizome has good anti-cough and expectorant effects.

Key words: Alpinia japonica, volatile oil, antitussive, expectorant