The Mechanism Of Matrine And Glycyrrhizic Acid Against Porcine Reproductive And Respiratory Syndrome Virus

Porcine reproductive and respiratory syndrome(PRRS)is one of the diseases that threaten the development of aquaculture all over the world in recent two decades,the clinical findings include the reproductive barrier of sows,the quantity of semen decrease in boars and the piglets suffer pneumonia after weaned,grow slowly,body function decrease and with high mortality rate.Porcine reproductive and respiratory syndrome virus(PRRSV)is the pathogen of PRRS.Now a days,there are still no effective treatment of PRRSV,the infection of PRRSV is avoided mostly through prevention measures.In order to investigate the effects and mechanism of matrine and glycyrrhizic acid inhibiting the process of PRRSV infect Marc-145 cells,in this study,the inhibitory effects of matrine and glycyrrhizic acid on PRRSV were preliminarily explained by immunofluorescence assay and three methods of administration,preventive treatment,therapeutic effect and direct killing.The structural protein GP4 and cell receptors CD163 and CD151 have the relationship to the PRRSV absorption and internalization period,nsp9 and nsp10 are critical protein related to PRRSV replication,TLR3 and IFN-? are closely related to the antiviral effect of cells.Therefore,the inhibition of matrine and glycyrrhizic acid on the expression of PRRSV GP4 and CD163,CD151 of Marc-145 cells in the process of of internalization and adsorption,and the prevention effect,and the effects on expression of PRRSV nsp9,nsp10 and TLR3,IFN-? of Marc-145 cell on PRRSV replication were detected to determine the inhibitory effect of matrine and glycyrrhizic acid on PRRSV.The results indicate that the matrine has the effect of treat,kill directly,inhibit absorption and internalization to PRRSV.Glycyrrhizic acid has the effect of prevent,treat,kill directly,inhibit absorption and internalization to PRRSV.The PRRSV absorption is inhibited by matrine through decrease the expression of GP4 and CD163,and the expression of CD163 is increased by matrine at the period of internalization.The infection of PRRSV is prevented by glycyrrhizic acid through decrease the expression of GP4,CD163 and CD151,the absorption of PRRSV is inhibited through decrease the expression of GP4 and CD163,and the internalization is inhibited through reduce the expression of GP4,meanwhile increase the expression of CD163 and CD151.Both drugs are effective to treat PRRSV,the mechanism is via reduce the expression of nsp9 and nsp10,which are the key proteins of PRRSV replication.The expression of TLR3 is promoted by PRRSV but inhibited by both drugs at early time,and the expression of TLR3 is inhibited by PRRSV at later period,both drugs can increase it.The expression of IFN-? is decreased by drugs at later period and increased at last period.The mechanism of matrine and glycyrrhizic acid is mostly the same except glycyrrhizic acid has the effect of prevention but matrine does not have,and the mechanism of inhibit PRRSV internalization is different.