The therapeutic effect of Yinhuangerchen mixture on Avian infectious laryngotracheitis

ABSTRACT The study was conducted to investigate the effect of Yinhuangerchen mixture (YM) on Avian infectious laryngotracheitis (AILT) induced by artificial infection and provide a scientific basis for its clinical application. A total of 200 chickens were challenged with infectious laryngotracheitis virus (ILTV). At 72 h post-challenge, the chickens were treated with different doses of YM or the Chinese herbal medicine Houyanjing powder. The relative expression of ILTV, the pathological changes of trachea, and the number of SIgA-secreting cells were detected. Thin-layer chromatography results confirmed that the YM contained Scutellaria baicalensis, Flos lonicerae, Pericarpium citri reticulatae, and Liquorice. The AILT model was successfully established by artificial infection. In the high-dose YM group (HD) and middle-dose YM group (MD), the effective rate of treatment was 100 and 96.7%, respectively, and the overall cure rate was 83.3%. In addition, the results of necropsy showed that the degree of tissue damage in chicken trachea was relatively low. Compared with positive control group, HD and MD chicken had lower relative expression of ILTV but more SIgA-secreting cells. In conclusion, YM can reduce ILTV level in tissue, mitigate tissue damage caused by infection, and enhance mucosal immunity having obvious therapeutic effect on AILT.