Study on the Mechanism of JZKFY Treatment of Cough Induced by Respiratory Syncytial Virus Infection

OBJECTIVE To investigate the effect and mechanism of JZKFY on increaseed cough sensitivity of young guinea pigs after being infected with respiratory syncytial virus(RSV). METHODS Young guinea pigs were randomly divided into control group， model group， Benproperine group and JZKFY(1.3， 2.6g/kg) group. In addition to the control group， every guinea pig were treated with 106.29 TCID50 mL-1 titer of RSV solution， and the control group was given the same volume of virus-free DMEM solution. Every group were treated with medicine from the second day. The cough latency and frequency of guinea pigs were detected by citrate cough test at the 8th day; investigating the total number of leukocyte in alveolar lavage; the levels of TNF-α、IL-4、IL-13 were investigated by Elisa; the expression of nerve growth factor (NGF)， substance P (SP)， neurokinin1 (NK-1) in bronchus were detected by immunohistochemical staining; the expression of NGF and NK-1 in lung tissue were detected by Western blotting. RESULTS JZKFY could inhibit the increase of the number of cough caused by RSV infection， decrease the total number of leukocyte and the contents of TNF-α， IL-4 and IL-13 in bronchoalveolar lavage fluid， improve bronchial inflammation and reduce the expression of NGF，NK-1in bronchus and the expression of NGF and SP in lung tissue. CONCLUSION JZKDY can improve the inflammatory response inducted by RSV and have a therapeutic effect on cough after infection. The mechanism may be related to reduce the airway inflammatory reaction， decrease neurogenic medium and adjust cough sensitivity.