Inhibition Of Qingying Oral Liquid On Replication Of H1N1 Swine Influenza Virus

Swine influenza is an immunosuppressive disease caused by swine influenza virus.It can cause fever and acute respiratory symptoms clinically.It has a very high incidence and is prone to secondary diseases such as porcine reproductive and respiratory syndrome and mycoplasma pneumonia.The pig industry has brought serious economic losses.As a "mixer" of viral gene recombination and the production of new antigen subtype strains,swine influenza virus plays a very important role in the ecological distribution and genetic evolution of the entire influenza virus.Therefore,for the stability and development of global animal husbandry and the safety of human public health,it is of great significance to strengthen the prevention and control of swine flu viruses and monitoring methods.Nowadays,the main way to prevent and control swine flu is to immunize animals and use anti-influenza drugs.However,due to the special structure of influenza virus,it can continuously produce new virus subtypes through high mutation rate and gene rearrangement,making Currently,vaccine immunity is relatively lagging.In terms of drug development,it mainly includes M2 ion channel blockers and neuraminidase inhibitors.However,due to amino acid mutations,drug resistance is becoming stronger.Therefore,there is an urgent need to develop new anti-influenza drugs.Swine influenza is an immunosuppressive disease caused by the swine influenza virus,which can cause fever and acute respiratory symptoms with a high incidence and is easily followed by diseases such as porcine reproductive and respiratory syndrome and Mycoplasma pneumonia,causing serious economic losses to the pig industry.Swine influenza viruses play a very important role in the ecological distribution and genetic evolution of influenza viruses as a "hybrid" for viral genetic recombination and the production of new antigenic subtypes.Therefore,it is important to strengthen the prevention and control of swine influenza viruses and the means of surveillance for the stability and development of the global livestock industry and for the safety of human public health.The main methods used today to prevent and control swine influenza are immunisation of animals and the use of anti-influenza drugs,but due to the special structure of influenza viruses,which can constantly produce new virus subtypes through high mutation rates and gene rearrangements,vaccination is currently lagging behind.Drug development,which mainly includes M2 ion channel blockers and neuraminidase inhibitors,is however becoming increasingly resistant due to mutations in amino acids.Therefore,there is an urgent need to develop new anti-influenza drugs.In monitoring swine influenza viruses in Shandong Province,our group found an increase in incidence and mortality rates in 2020 compared to previous years.The virus was isolated and purified and tested in vitro and in vivo for its antiviral effects using a new Class III national veterinary drug,Qing Ying Oral Liquid,developed by the project team.Qingying Oral Liquid is modified from Qingying Decoction,Qingying Decoction is a heat-clearing agent.The prescription comes from the ancient Chinese traditional Chinese medicine "Tiaobian",which consists of rhino horn(replaced by buffalo horn),rehmannia glutinosa,silver flower,forsythia,xuan It is composed of ginseng,salvia miltiorrhiza,Ophiopogon japonicus,coptis and bamboo leaf heart,which can clear away heat and nourish yin,and treat the syndrome of heat entering the camp.Qingying decoction has been effectively used in clinical treatment,in the treatment of Japanese encephalitis,Epidemic cerebrospinal meningitis,sepsis,enteric typhoid fever or other febrile diseases have good effects,but there is no report on the efficacy of influenza virus.Therefore,this topic uses the swine influenza virus isolated above,using mice(C57BL/6)and MDCK cells as models,to study the effect of Qingying oral liquid in inhibiting swine influenza virus replication.Mainly include the following aspects:(1)In vivo experiments: By conducting gavage drug experiments on mice at the maximum dose of Qing Ying Oral Liquid for 14 days,blood was collected to test blood routine and biochemical indexes,and it was determined that the drug had no toxicity;by infecting the virus a few days after gavage of Qing Ying Oral Liquid,the mental condition of mice was observed at 0,2,4 and 6 days after infection,body weight measurement,lung index of mice after autopsy and HE staining,etc.It was determined that Qing Ying Oral Liquid had a significant inhibitory effect on H1N1 SIV in mice.(2)In vitro experiments: The Reed Muench method calculated the TCID50 of H1N1 SIV on MDCK cells as 10-3.66/100?L;q RT-PCR was used to detect that Qingying Oral Liquid had a significant inhibitory effect on H1N1 SIV,and the best inhibitory effect was found in the pre-adsorption period.It was found that Qing Ying Oral Liquid could effectively inhibit the nuclear output of NP protein of H1N1 SIV by immunofluorescence test.The effect of Qingying Oral Liquid on other influenza strains(H9N2)was also tested,and the drug was also found to have a good inhibitory effect on H9N2.Through the above tests,the inhibitory effect of Qingying Oral Liquid on H1N1 SIV was initially clarified and can be promoted in clinical use.