Abstract: Objective To investigate the effect of Xiaoer Qingfei mixture on viral load and inflammatory factors in lung tissues of young rats with respiratory syncytial virus（RSV） induced inflammatory lung injury.Methods Eighteen young SD rats were randomly divided into three groups：normal group，RSV group，and the intervention group of Xiaoer Qingfei mixture，with 6 rats in each group.RSV inflammatory lung injury model was established by nasal drip method. Real-time PCR was used to detect the viral load in rat lung tissues. Hematoxylin-eosin staining（HE staining） was used to observe the pathological changes of lung tissue. ELISA method was used to detect the content of IL-8 and TNF-α in BALF. The effect of Xiaoer Qingfei mixture on the above indexes was observed.Results （1）In terms of viral load: compared with the normal group，the RSV content in the lung tissue of the RSV group and the intervention group of Xiaoer Qingfei mixture was significantly increased（P＜0.05）；compared with the RSV group，the RSV content in the lung tissue of the intervention group was significantly lower（P＜0.05）.（2）In terms of pathological injury and wet-dry ratio：compared with the normal group，the pathological injury score and the wet-dry ratio of the lung in the RSV group and the Xiaoer Qingfei mixture intervention group were higher（P＜0.05）；compared with the RSV group，the injury in the intervention group was significantly improved（P＜0.05）.（3）In terms of the content of IL-8 and TNF-α in BALF: compared with the normal group，the content of IL-8 and TNF-α in RSV group and the intervention group of Xiaoer Qingfei mixture was significantly higher（P＜0.05）；compared with RSV group，the content of IL-8 and TNF-α in the intervention group of Xiaoer Qingfei mixture was significantly lower（P＜0.05）.Conclusion RSV intranasal drip can successfully establish RSV inflammatory lung injury model in young rats. The intervention of Xiaoer Qingfei mixture can reduce the viral load of lung tissue in RSV inflammatory lung injury of young rats, inhibit the level of inflammatory factors, and improve the degree of lung injury.

Key words:

Respiratory syncytial virus, Xiaoer Qingfei mixture, IL-8；TNF-α；Rat