葫芦多糖体外抗鸡新城疫病毒作用的研究

为研究葫芦多糖抗新城疫病毒（Newcastle disease virus，NDV） 活性，本试验采用水提醇沉法提取葫芦总多糖及4种分级多糖，通过苯酚-硫酸法及红外光谱对葫芦多糖进行检测，MTT法测定各级多糖对鸡胚成纤维细胞（CEF）的安全浓度，多糖的安全浓度统一定为78.125 μg/mL，以3种加药方式（先加多糖后接种病毒、先接种病毒后加多糖、多糖和病毒感作后加药），检测葫芦多糖对NDV的阻断、抑制及直接杀灭作用。结果表明，葫芦总多糖及4种分级多糖均具有抗NDV活性，其中对NDV的抑制作用及直接杀灭作用强于对NDV的阻断作用。70%、80%梯度醇沉的葫芦多糖（LSP₇₀、LSP₈₀）及总多糖（LSP_t），抑制作用下的病毒抑制率分别为40.41%、44.54%、61.85%，杀灭作用下的病毒抑制率分别为44.74%、58.76%和59.38%，阻断作用下对NDV的抑制率，其中LSP₈₀组最高达37.14%，其余各组均低于25%。综上可知，70%、80%梯度醇沉的葫芦多糖及葫芦总多糖的抗NDV活性较好，可作为进一步研究的材料。

Study on Antiviral Effect of Polysaccharides from Lagenaria siceraria (Molina) Standl.on NDV in vitro

To research on polysaccharides from Lagenaria siceraria (Molina) Standl.against Newcastle disease virus (NDV).Total polysaccharide and four different solvent extractions of Lagenaria siceraria (Molina) Standl.were extracted by the methods of hot water extraction and ethanol precipition in this study.The content of polysaccharide was measured by phenol-sulfuric acid method and infrared spectroscopy method.The safe concentration and growth of chick embryo fibroblast (CEF) were assayed by MTT method,in order to facilitated the comparison under the same level,the safe concentration was united as 78.125 μg/mL.Under the safety range of concentration,detected the block-virus activity,anti-virus activity and virus-killing activity of polysaccharides through the ways of pre-adding polysaccharides,post-adding polysaccharides and adding polysaccharides with NDV.The results showed that the direct inactivation and propagation inhibition activity of total polysaccharide and four different solvent extractions were stronger than anti-absorption function.Anti-virus inhibition rate of 70%,80% gradient alcohol precipitation of polysaccharides from Lagenaria siceraria (Molina) Standl.(LSP₇₀,LSP₈₀) and total polysaccharide (LSP_t)were 40.41%,44.54% and 61.85%,virus-killing inhibition rate were 44.74%,58.76% and 59.38%.LSP₈₀ had the highest virus inhibition rate as 37.14% in the block-virus activity of those five polysaccharides.In summary,70%,80% gradient alcohol precipitation and total polysaccharide in polysaccharides possessed better activity and would be as the materials for further research.