Protective Effects Of Mahuang Lianqiao Chixiaodou Decoction On Influenza PR8 Virus Infected Mice

Viral pneumonia is an acute and highly contagious disease that poses a great threat to the livestock industry and human health and safety.The disease is currently treated mostly with symptomatic,antiviral and supportive therapy.Mahuang Lianqiao Chixiaodou decoction was first published in Zhang Zhongjing’s Treatise on Febrile Diseases,and is used to treat the loss of lung circulation and lowering of the lung and the blockage of water-dampness.With the accumulation of experience in clinical practice,the scope of its research and application is being extended,mostly in liver disease,lung disease and kidney disease,etc.,and its application is promising.Mahuang Lianqiao Chixiaodou decoction combines the functions of promoting exaggeration,relieving dampness,protecting the liver,clearing heat,and tonifying deficiency.It may be effective against viral pneumonia.Therefore,this study was carried out to investigate the protective effect of Mahuang Lianqiao Chixiaodou decoction on viral pneumonia.A mice pneumonia model of influenza virus strain PR8 infection was prepared and administered by gavage with different doses of Mahuang Lianqiao Chixiaodou decoction to evaluate its protective effect on the mouse pneumonia model of influenza virus strain PR8infection,with a view to providing a theoretical basis for the prevention and treatment of influenza virus and other viral pneumonia in clinical practice.The main research elements and results are as follows.(1)The Kunming mice were divided into six groups(n=10,18-22 g,Half male and half female),inoculated with virus and administered with drugs.The mice were observed daily and their weight and mortality were recorded.The results showed that the weight gain rate of high dose group was significantly higher than that of influenza virus model group(P<0.01).The mortality rate of influenza virus model group was significantly higher than that of blank control group,and the mortality rate of medium dose group was significantly lower than that of influenza virus model group(P<0.01).Mahuang Lianqiao Chixiaodou decoction significantly reduced the mortality and increased the weight gain rate of mice.(2)The histopathological changes were observed by HE staining,and the results showed that compared with the influenza virus model group,the pathological damage of lung and spleen of the mice in the low dose of Mahuang Lianqiao Chixiaodou decoction group was significantly reduced.The lung tissue of mice in each group was taken to determine the lung index.The results showed that the lung index of mice in influenza virus model group was significantly higher than that in blank control group(P<0.01).There was no significant difference between the lung index of the influenza virus model group and the three dose groups of Mahuang Lianqiao Chixiaodou decoction group(P>0.05).The lung index of mice in dexamethasone positive control group was significantly lower than that in influenza virus model group(P<0.01).(3)The viral load in the lung tissue of mice was measured by q PCR and the results showed that the viral load in the lung tissue of mice in the influenza virus model group was significantly higher compared with the blank control group(P<0.01),and the viral load in the lung tissues of mice in the Mahuang Lianqiao Chixiaodou decoction administration group was significantly lower compared with the influenza virus model group(P<0.01).(4)ELISA was used to detect the levels of cytokines in serum and q PCR was used to detect the m RNA expression of cytokines in lung tissue.The results showed that compared with the influenza virus model group,the levels of IFN-γand IL-10 in serum of mice in the Mahuang Lianqiao Chixiaodou decoction administration groups were significantly increased(P<0.05),but the levels of IL-1βand TNF-αwere not significantly affected(P>0.05).The results of cytokine m RNA expression in lung tissue were similar to those in serum.(5)The number of immune cells in the spleen was measured by flow cytometry.The results showed that compared with the influenza virus model group,the number of CD4~+T cells,CD8~+T cells and B cells in the spleen of the three dose groups of Mahuang Lianqiao Chixiaodou decoction could be significantly increased(P<0.05).Compared with the blank control group,the number of macrophages in the influenza virus model group was significantly reduced(P<0.05).Compared with the influenza virus model group,the number of macrophages in the middle dose of Mahuang Lianqiao Chixiaodou decoction group was significantly increased(P>0.05).(6)The content of MDA and activity of SOD,AST and ALT in serum were detected by the kit.The results showed that the content of MDA in serum of high-dose group was significantly lower than that of model group(P<0.05),and there was no significant difference in SOD activity of serum among the six groups(P>0.05).The activity of AST in serum of mice in three doses of Mahuang Liaoqiao Chixiaodou decoction groups was significantly lower than that in model group(P<0.05).There was no significant difference in ALT activity between the three dose groups of Mahuang Lianqiao Chixiaodu decoction and the model group(P>0.05).In conclusion,Mahuang Liaoqiao Chixiaodou decoction has certain protective effects on influenza virus pneumonia in mice,which can reduce the mortality rate,increase the weight gain rate,and has certain anti-inflammatory,immunomodulatory and anti-influenza virus effects.