展枝马尾藻硫酸多糖对呼吸道合胞病毒的抗病毒活性及其机理研究

摘要

目的研究从褐藻展枝马尾藻Sargassumpatens中分离到的一种硫酸多糖SP2的抗病毒活性及抗病毒作用机理.方法通过细胞致病效应实验、MTT测定和空斑形成抑制实验对该多糖的抗病毒活性、细胞毒性和可能的抗病毒机理进行测定.结果通过空斑形成抑制实验测定结果显示,该多糖对呼吸道合胞病毒有好的抗病毒活性,其EC50值为1.1但没有抗流感病毒A和B、副流感病毒的活性.多糖的CC50高达3000 μg·mL-1.其对呼吸道合胞病毒的抗病毒选择性指数被估计大于2727.用SP2预处理宿主细胞,不显示任何对病毒感染的保护作用.SP2对呼吸道合胞病毒有一定的杀病毒活性,其EC50值超过100μg·mL-1.时间加入实验证明,只有在37℃呼吸道合胞病毒吸附时期加入SP2才能完全抑制病毒的复制.结论 SP2可能是一种有潜力的抗呼吸道合胞病毒感染的多糖.其对呼吸道合胞病毒的抗病毒作用机制与抑制病毒的吸附有关.%Objective To detect the antiviral effect and its antiviral mechanism of the sulfated polysaccharide SP2 isolated from the brown alga Sargassum patens C. Ag. against RSV.Methods The antiviral activity,cytotoxicity and its possible antiviral mechanism were assayed by cytopathogenic effect (CPE) inhibition assay,MTT assay and plaque reduction assay. Reduction assay when it was added during virus adsorption. It did not show any antiviral activity against influenza A and B viruses and parainfluenza type 3 virus up to the concentration of treatment of cells with SP2 did not protect the cells from RSV infection. This polysaccharide addition assay showed that when SP2 was present only during virus adsorption phase at 37℃, it could significantly inhibit RSV-induced plaque formation. Conclusions SP2 might be a potent substance for treating RSV infection. The mode of action of SP2 might depend on inhibiting RSV attachment to host cells.