| Newcastle disease (ND) originated NDV is acute, septico-uprightness and hyperinfection, and death rate is high.It threatens the poultry industry of our coutry.At present, the prevention and cure of ND depend on vaccine inoculation especially the inferior vaccine, and there is not better curative.Anti-virus Western medicine easily brings about drug resistance, cuts down curative effect, and recur pathogenetic condition.It is the problem that we study the mew medicine to prevent and cure ND. Chinese crude drug is famous of effectiveness and without adverse reaction, Chinese crude drug can cure viral infection disease.According to the results of the screening various polysaccharid in chinese traditional herbs, which can against NDV, we proceed the following studies about Scutellaria baicalensis Georgi polysaccharideWe made polysaccharide through the condense recirculate method, The L933orthogonal design was hired to investigate extraction conditions of extraction. The optimizal condition for Scutellaria baicalensis Georgi extraction was as following: duration time was 60 min while the ratio of dry alage to water was 1:20; temperature is 60℃. ; dissolvent concentration is 85%, in this condition, the extract rate of polycose extracted from Scutellaria baicalensis Georgi was 19.77%; measured by phenol- sulphuric acid method, and the content was 0.71%; The optimizal condition for Codonpsis Pilosula extraction was as following: duration time was 100 min while the ratio of dry alage to water was 1:20; temperature is 40℃. ; dissolvent concentration is 85%, in this condition, the extract rate of polycose extracted from Codonpsis Pilosula was 29.03%; measured by phenol- sulphuric acid method, and the content was 2.87%; deproteinized by Sevage method; dryed the extraction by vacuum drying method;dialysed the small molecular substance and inorganic substance with filter bag;and study the activity of anti-NDV in vitro. The result shows: under pre-adding polysaccharide, when the concentration of Scutellaria baicalensis Georgi polysaccharide is 125μg·mL-1 and 62.5μg·mL-1, it can conspicuously against NDV; when the concentration of polysaccharide is 31.25μg·mL-1 and 15.63μg·mL-1, it can against NDV; when the concentration of polysaccharide is 7.81μg·mL-1, it can not against NDV, and the result of Codonpsis Pilosula polysaccharide is same with Scutellaria baicalensis Georgi polysaccharide. and TI of Scutellaria baicalensis Georgi polysaccharide and Codonpsis Pilosula polysaccharide is 8. Under pre-adding virus, the result of Scutellaria baicalensis Georgi polysaccharide is same as above,but Codonpsis Pilosula polysaccharide is different, when the concentration of Codonpsis Pilosula polysaccharide is 125μg·mL-1 and 62.5μg·mL-1, it can conspicuously against NDV; when the concentration of polysaccharide is 31.25μg·mL-1 ,, it can against NDV; when the concentration of polysaccharide is 15.63μg·mL-1 and 7.81μg·mL-1, it can not against NDV ,and TI of Codonpsis Pilosula polysaccharide is 4.Under simultaneous adding polysaccharide and virus, when the concentration of Scutellaria baicalensis Georgi polysaccharide is 125μg·mL-1 and 62.5μg·mL-1, it can against NDV, when the other concentration, it can not against NDV, and TI is 2, and the all concentration of Codonpsis Pilosula polysaccharide can not against NDV.The result shows Scutellaria baicalensis Georgi polysaccharide and Codonpsis Pilosula polysaccharide can not directly kill virus.Through the study,we make sure the optimizal condition of extraction,and the result of study confirms Scutellaria baicalensis Georgi polysaccharide and Codonpsis Pilosula polysaccharide can against NDV in vitro, and we prove it through the chick embryo experiment.The activity against NDV need the further study in vivo, and the study of new medicine that can prevent and cure ND is on the basis of the result. |
