Study On The Antiviral Activity And Preliminary Mechanism Of Sulfated Polysaccharides From The Caudex Of Undaria Pinnatifida

Objective:In order to examine the antiviral effect of sulfated polysaccharides from the caudex of Undaria pinnatifida against herpes simplex virus type-1(HSV-1) and assess its potential for clinical applications,antiviral activity and mechanism experiments of sulfated polysaccharides from the caudex of Undaria pinnatifida were carried out in this study.Method:1.MTT method was carded out to determine the 50%toxic concentration of sulfated polysaccharides from the caudex of Undaria pinnatifida.2.CPE method and plaque reduction assay were used to determine the antiviral activity of sulfated polysaccharides from the caudex of Undaria pinnatifida.3.CPE method and plaque reduction assay were applied to study the antiviral mechanism of sulfated polysaccharides from the caudex of Undaria pinnatifida by four action modes.4.RT-PCR was applied to determine the effect of sulfated polysaccharides from the caudex of Undaria pinnatifida to the transcriptional expression of US6 and UL30 genes.5.Flow cytometry was applied to analyse the turbulence to cell cycle by HSV-1 infection6.CPE method was carded out to study resistance of HSV-1 to sulfated polysaccharides from the caudex of Undaria pinnatifida.Results:1.The TC₅₀(50%toxic concentration) value of UPP1 and UPP2 for Vero cells growth both were more than 10000μg/ml;the IC₅₀(50%inhibiting concentration) of UPP1 and UPP2 for HSV-1 yield reduction assay were 8.04μg/m,13.54μg/ml,respectively;and the therapeutic index(TI) were more than 1244,739,respectively.2.CPE,MTT,PRA results showed that sulfated polysaccharides from the caudex of Undaria pinnatifida can inhibit CVB₃ and HSV-2.3.Results indicated that UPP1 affected on viral adsorption and penetration;UPP2 inactivated HSV-1directly;both can inhibit the replication of the virus;but neither had effect on HSV-1 releasing from infected Vero cells to medium.4.Contrast to HSV-1 control,UPP1 can depress the transcriptional expression of US6 and UL30 genes distinctly(p＜0.05),while UPP2 only depressed the transcriptional expression of UL30 gene(p＜0.05).5.Flow cytometry results implied UPP2 can regulate the turbulence cell cycle by HSV-1 infection.6.HSV-1 mutant strain did not find in the effect of the purfied sulfated polysaccharide from the caudex of Undaria pinnatifida.Conclusion:In brief,the pharmacological experiments confirmed that sulfated polysaccharides from the caudex of Undaria pinnatifida indeed showed strong anti-HSV-1 activity.The possible mechanism might include its effects on:(1) virus absorption;(2) virucidal activity;(3) HSV-1 gD gene and DNAP gene transcription;(4) rugulate the turbulence cell cycle infected by HSV-1.