RESUMO
AIM: To study antiasthmatic effect of citral from aqueous extract of fruit of cubeb litsea tree and its mechanism.METHODS: By inducing asthma with Ach-histamine method in guinea pig,cough with ammonia in mice and the output quantity of phenol red from the trachea in mice,the antiasthmatic was observed,preventing cough and eliminating phlegm effect of citral. By measuring the tension of guinea-pig isolated tracheal rings,the both influence of citral was observed on isolated guinea pig tracheal rings and inhibition's effects of citral on contraction induced by Ach.RESULTS: Citral prolonged apparently the incubation period of asthma due to Ach-histamine solution in guinea pig and the coughing incubation period,reduced coughing frequency induced by ammonia in mice,increased excretion of phenol red from the respiratory tract in mice,inhibited the constrictions induced by Ach,and shifted the dose-effect curves of Ach to the right.CONCLUSION: Citral has functions of expelling phlegm,relieving cough and resisting asthma,satisfactory bronchi spasmolysis.