Objective: To study the effects of Qingfei oral liquid on airway inflammation and hypersensitivity in a respiratory syncytial virus (RSV) infected murine asthma model. Method: Sixty 6-8-week-old male Balb/C mice were equally divided into six groups by random:the normal group (CON)

model group (RSV+OVA)

Qingfei oral liquid group [high dose (HD)

middle dose (MD)

low dose (LD)]

and ribavirin group (LB).The asthma model was reproduced by sensitization and nebulizer inspired OVA

followed by repeated inhalation of RSV for three consecutive times to obtain RSV-infected asthma model (1.0×106 PFU/mL in 50 μL). Qingfei oral liquid groups were administered with different doses. The normal control group was administered with normal saline. LB group received ribavirin injection ip 24 h after of the last administering

Buxco RC system was used to detect airway hyperresponsiveness

ESO cells infiltration were measured in bronchoalveolar lavage fluid (BALF) fluid

and inflammation was assessed in lung tissue by HE staining

PAS staining

VG staining. Result: The proportion of BALF's eosinophils (EOS%) in model group was significantly higher than that in the normal group (P<0.05).Airway hyperresponsiveness in model group was significantly higher than that in normal group (P<0.01). Qingfei oral liquid and Ribavirin cleared RSV's infection and significantly improved airway hyperresponsiveness compared with the model group (P<0.05)

among which Qingfei oral liquid middle-dose group had the most significant effect. There was no significant difference in airway functions compared with normal group. Qingfei oral liquid middle-dose group significantly reduced lung tissue edema and inflammatory cell infiltration

airway secretions and collagen hyperplasia around airway compared with model group. Conclusion: Qingfei oral liquid middle-dose group can significantly reduce inflammation of lung tissues and airway hyperresponsiveness in RSV infected murine asthma model.