Inhibition And Mechanism Of Compound Chinese Medicinal Ingredients Against Newcastle Disease Virus Infection In Vitro And In Vivo

Newcastle Disease,which is caused by Newcastle disease virus(NDV),is an acute,febrile and highly contagious disease.It is one of the main diseases which can cause huge economic losses in poultry industry.The disease spread rapidly to most areas of the world.Effective drugs for treatment ND have not been found by now.It showed that formula 1,5,6,7,9,10 had better anti-NDV effect in earlier stage studies.Based on these studies,the purpose of this topic is to survey the anti-NDV effect of compound Chinese medicinal ingredients in vitro,therapeutic effect of artificial infection chicken and mechanism research of anti-NDV in vivo.Our research is to provide the theory basis for the clinical application of the formula.1.Effect of compound Chinese medicinal ingredients against NDV infection in vitroThe six prescriptions were determined for their effect on adsorption,reproduction and release of NDV virulent strain(F48E8)when it infected chick embryo fibroblast(DF1)by the method of MTT and observation of cytopathic effect(CPE).The results showed that the six prescriptions could prevent virus adsorpting of cells or block virus which adsorpted the cells in the adsorpt inhibition assay.It suggested that reagent concentration,prescription adding way and virus adsorption time could significantly affect the virus infection of cells.The OD570 values of formula 1,5,6,10 test groups were significantly higher than virus control group in the virus proliferation inhibition assay and release inhibition assay.The results showed that antiviral activity of the six prescriptions was attributed to block virus adsorption to cells and/or interfere with the virus proliferation and release.2.Effects of compound Chinese medicinal ingredients on controlling of chicken NDTwo hundred and forty three weeks non-immunized white chicken were randomly divided into 8 groups which were consisted of normal control group,viral control group and six treatment groups,were separately feed.Excepting the normal control group,other groups were injected with virulent NDV by intramuscular injection.Eight hours after challenge,six treatment groups were given the different concentrations of formula respectively by oral administration for three days,two times per day.the control groups were given with same dose of PBS.After challenge,effects of prescriptions on treating ND were evaluated by morbidity and mortality,immune organ index,and the content of IFN-?and IFN-? in serum.The results showed that,compared with the virus control group,morbidity and mortality of formula 5 and 10 at middle concentration was lower,immune organ index was larger;four-day and five-day after challenge,the concentration of IFN-?and IFN-? in serum of prescription 5 at middle dose were obviously higher than virus control group.This manifested that compound Chinese medicinal ingredients had a certain therapeutic effect.These foemula could promote the development of chicken immune organs and regulate the secretion of interferon which enhanced its treatment effect on ND.3.Mechanism of compound Chinese medicinal ingredient 5 against NDV infection in chickenOne hundred and fifty 100-day-old white chicken were randomly divided into 5 groups which were consisted of normal control group,viral control group and three treatment groups,were separately feed.Excepting the normal control group,other groups were injected with virulent NDV by intramuscular injection.Eight hours later,three treatment groups were given the different concentrations of formula 5 by oral administration for three days,two times per day.The control groups were given with same dose of PBS.The ability of lymphocyte proliferations and concentrations of serum IFN-?and IFN-? were determined by MTT method and ELISA method respectively at one day before challenge and 1,2,3,4 days after challenge.According to the instructions,GSH-Px,SOD,CAT,MDA and NO were also determined.The results showed that the lymphocyte proliferations of prescription 5 at middle dose were significantly higher than virus control group,while the concentrations of interferon of formula experimental groups were higher than virus control group at four-day and five-day after challenge.The results suggested that compound Chinese medicinal ingredients could enhance body immune function and determinate action indirectly on resisting NDV.Formula 5 could increase the vitality of GSH-PX and SOD,and decrease the level of MDA and NO in the experimental groups.The results conformed that compound Chinese medicinal ingredients could effectively eliminate the free radical and strengthen the Chicken's antioxidative function.