The Impact Of Qingfei Oral Liquid On IL-2 Level And Pathological Changes Of Lung Tissue In RSV-infected Mice

Objective:To explore the mechanism of Qingfei Oral liquid resisting RSV by observing the impact and pathological changes of IL-2 expression level in the lung tissue of RSV-infected mice exerted by the medicine.Methods:50 BALB/c mice were randomly and equally divided into 5 groups:control group, model group, ribavirin group(0.0025 g/ml), high dosage group (4 g/ml), low dosage group (1.33 g/ml). All mice in 5 groups were placed into a sealed transparent container and were anesthetized with diethyl ether. While the control group stimulated by the same amount of saline, the rest of 4 groups were given RSV through nasal passage to establish models, after 48 hours, all mice were given medicine through gastric perfusion once a day. Mice were executed 72 hours after administration. Finally observing the extent of pathological changes in lung tissue, applying ELISA and RT-PCR to detect the bronchoalveolar lavage fluid(BALF) and the changes of cytokine IL-2 in lung tissue respectively.Results: ①The degree of pathological changes:the pathological score of model group increased remarkably compared with blank group(P<0.01). Compared with model group, the pathological score of high dosage group and ribavirin group decreased remarkably(P<0.01), while the low dosage group decreased slightly (P<0.05). ②After infected with RSV,cytokine IL-2 in bronchoalveolar lavage fluid in model group decreased remarkably than the blank group. After treatment, the expression of cytokine IL-2 in BALF in high dosage group, low dosage group, ribavirin group increased sharply than model group(P<0.01). ③IL-2 mRNA in BALF decreased sharply in model group than blank group(P<0.01) after infected with RSV,increased remarkably in high dosage group and ribavirin group,and increased slightly in low dosage group(compare with model group, P<0.05)after treatment.Conclusion:By taking Qingfei Oral liquid in the early stage,RSV-infected-induced inflammatory changes can be inhibited, the level of cytokine IL-2 and expression of IL-2 mRNA in lung tissue can be promoted,It provides the theoretical base for Qingfei Oral liquid treating RSV-infected pneumonia.