| Polysaccharide is a kind of important biological macromolecules.It has many functions,such as immune regulation,anti-viral and so on.Sulfated polysaccharide is a kind of polysaccharide with sulfuric radical,after sulfated modification the modifiers possesses stronger biological activities.In this research,Lagenaria siceraria?Molina?Standl.was selected as experimental materials,the extraction factors of polysaccharides were optimized by using response surface analysis.In vitro experiments was carried out to select the polysaccharides with the strongest anti-NDV and lymphocyte proliferation activity,and the selected polysaccharides were purified and sulfated.Finally,the strongest active component of anti-NDV and enhancing immune activity of LSP or sLSP was selected through in vivo and in vitro experiments.The main results are as follows:1.The optimum extraction conditions of crude polysaccharide from Lagenaria siceraria?Molina?Standl.?cLSP?were following as:extraction temperature of 82?,water to material ratios of 24:1 mL/g,extraction time 2.3 h and the extraction cycle was 2.Under such condition the extraction rate of polysaccharide up to 5.81±0.24%.2.Anti-viral effect of cLSP on NDV in vitro showed that,cLSPt and four different solvent extraction have anti-NDV activity,the direct inactivation and propagation inhibition activity were stronger than anti-absorption function,in this five polysaccharides cLPSt possessed better activity.3.The effect of cLSP on chicken lymphocyte prolieration in vitro showed that,except cLSP30 other four kinds of cLSP can separate stimulate and coordinate stimulate with LPS to spleen lymphocyte of chicken at the appropriate concentration and,all of the cLSP can separate stimulate and coordinate stimulate with ConA to peripheral blood lymphocytes.cLSP50 showed strongest cell proliferation,proliferation rate to spleen lymphocytes and peripheral blood lymphocytes were 6.71%and 6.63%respectively.4.The purification and sulfated acid of cLSP showed that,the polysaccharides content of LSPt and LSP50 were 76.80%and 91.60%respectively.Infrared spectra of sLSP showed that,SLSPt has absorption peaks at 829 cm-1,1219 cm-1 and sLSP50 at 1262 cm-1,which is the characteristic absorption peak of sulfated polysaccharides,this indicates that the sulfated modifier is successfully prepared.5.Anti-viral effect of LSPt and its 4 kinds of sulfated polysaccharides on NDV in vitro showed that,cLSPt,LSPt and 4 different sulfated polysaccharides have anti-NDV activity,in which LSPt and sLSPt1.8possessed better activity.Curative effect comparison of LSPt and sLSPt1.8 on Newcastle disease in chickens showed that,both LSPt and sLSPt1.8 can improve and prolong antibody level,cure rate and,protection rate.In this two groups of drugs,sLSPt1.8 showed highest cure rate and,protection rate,respectively 26.7%,33.3%.6.The effect of LSP50 and its 4 kinds of sulfated polysaccharides on chicken lymphocyte prolieration in vitro showed that,proliferation of cLSP50 on chicken peripheral blood lymphocytes was significantly improved after purified?P<0.05?.LSP50 and sLSP501.2 showed strongest cell proliferation,proliferation rate to peripheral blood lymphocytes were 13.57%and 15.54%respectively.LSP50 and sLSP501.2 can improve and prolong antibody level,proliferation of lymphocytes,and secretion of IL-2,IL-6 and IFN-?for ND vaccinated chickens.The effect of LSP50 was stronger than that of sLSP501.2,in this two groups. |
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