Study On The Anti-Pseudorabies Virus Effects Of Bidens Pilosa L.

Pseudorabies?PR?is an infectious disease caused by Pseudorabies virus?PrV?and it is considered to be one of the most serious swine virus diseases in the pig breeding industry.In this paper,the extract of Bidens pilosa L.is used to investigate the anti-PrV effect in vitro and in vivo,and is applied to the farm to further study its anti-virus effect and its effect on pig production and immunity.1.The crude extract of Bidens pilosa L.?BPE?was obtained by extraction with water and precipitation with ethanol.And then the effects of BPE on cytopathic effect?CPE?of PrV and on the proliferation of BHK-21 cells infected by PrV were studied.The mechanism of anti-PrV was preliminarily investigated by indirect immunofluorescence?IFA?,real-time fluorescent quantitative PCR and in situ fluorescence detection of cell apoptosis.The results showed that treatment with 10 mg/mL,5mg/mL,2.5 mg/mL of BPE could significantly improved CPE and viability of BHK-21 cells infected by PrV?p<0.001?in the treatment mode and the direct virucidal mode,and exerted no significant effect in the prevention mode?p>0.05?.Results of IFA,real-time qPCR and apoptosis assay showed that the mechanism of anti-PrV of BPE was probably by inhibiting the expression of PrV gB gene and protein and reducing the apoptosis induced by viral infection to protect cells.2.Pseudorabies was induced in mice by PrV infection.Mice were divided into nine groups:blank control,low,medium and high dose of BPE,low,medium and high dose of extract from Bidens pilosa L.with other Chinese herbs?Bidens pilosa L.:Glycyrrhiza uralensis Fisch.:Gynostemma pentaphyllum.:Trifolium pratense L.=2:1:1:1?,PrV and positive control group.After gavage with the extracts for 7 days,the mice were subcutaneously injected with 10 LD₅₀0 of virus solution and then gavaged continuely.The death as well as the clinical symptoms of the challenged mice were observed within another 5 days.Results showed that treatment with BPE and its formulated preparation with other herbs?BFE?can delay the disease onset time and improve the clinical symptoms in mice infected with PrV.And the effect of BFE is better than BPE.Furthermore,the protective effect of fermented Bidens pilosa L.powders with other chinese herbs?FBFD?was investigated in mice.Mice were divided into blank control,low,medium and high dose of fermented FBF,PrV,and positive control group.After administered with FBF for 7 days,the mice were subcutaneously injected with 10LD₅₀0 of virus solution and then continuely administered with FBF.The death of the challenged mice was observed within 5 days.Results showed that the mice which treated with fermented FBF can delay the death time,improve the clinical symptoms in mice infected with PrV and reduce death rate.3.Fermented Bidens pilosa L.powder with other Chinese herbs,and added the fermented products to the basal diet in four gradients of0.5%,1%and 2%as additive for weaning piglets.The diarrhea rate,growth performance,feed intake and weight gain of weaned piglets during 28 days of experimentation were observed.After 28 days,the serum samples were prepared,the content of total IgG,IFN-?and positive rate of PrV,CSFV and PRRSV were detected.Results showed that FBF can improve reduce the diarrhea rate?P<0.05?,and increase the total IgG content in serum?P<0.001?,but it does not increase weight gain and the content of IFN-??P>0.05?.At the same time,it can reduce the positive rate of PRRSV infection in the same group of piglets.Due to the short period of pseudorabies virus viremia,the PrV virus nucleic acid could not be detected.In summary,Bidens pilosa L.exhibits the property of anti-pseudorabies virus in vitro and in vivo,and its formulated preparation with Trifolium pratense L.,Gynostemma pentaphyllum.and Glycyrrhiza uralensis Fisch.shows certain potential in reducing the diarrhea rate and improving immunity of piglets.