Extraction And Purification And Biological Activity Studies Of Polysaccharides From Abalone Visceral

The polysaccharides was obtained by using Haliotis discus hannai Ino viscera as material,the alkaline protease,neutral protease,vernase,papain,pepsin and trypsin as protease enzymolysis to release the polysaccharide chain.The experiments results showed that when used alkaline protease,the polysaccharide yield was the highest,which was 6.66%.Then by single factor experiment and the orthogonal experiment of alkaline protease,the optimum condition of alkaline protease extracting polysaccharides from abalone visceral was determined.The results of antioxidant activity showed that the concentration of polysaccharides from abalone viscera of 100%removal of hydroxyl free radical was 9.6 mg/mL,of reducing capacity at A700,0.485 was 8.16 mg/mL,and of 100%removal of ABTS radical was 7.5 mg/mL.All the three experiment results indicated that the polysaccharides had a good antioxidant activity.When the secondary enzymolysis of enzyme was pepsin,the polysaccharide content and antioxidant activity were the highest.Using sevage method and repeated freezing and thawing method to remove protein and hydrogen peroxide method to depigmentation,we got the high purity content of AVP.The total sugar content was 46.24 g/100 g and furonic acid,sulfuric acid,amino sugar and protein contents were 17.44,16.96,0.59 and 1.64 g/100 g in AVP respectively.The main monosaccharide compositions in AVP were D-galactose,D-xylose,D-mannose,D-glucose and D-glucuronic acid.Acute oral toxicity test results showed that AVP was non-toxic.The results of the bacteriostatic action of AVP(6.25,12.5,25,50 mg/mL)showed that the AVP could surpress reproduction of Staphylococcus aureus,Salmonella typhimurium and Escherichia coli significantly,but have a little weaker effect on Pseudomonas aerzuginosa.MTT assay showed AVP had a significant anti-tumor activity to gastric carcinoma cells MGC-803,while it had no influence upon proliferation of normal stomach cells GES-1.Morphological changes of MGC-803 cells after exposure to AVP indicated that the treated cells displayed typical morphological features of apoptosis:condensed chromatin,gradual disintegration of the nuclear membrane,and pyknotic(shrunken and dark)nuclei.The treated cells emitted orange and red fluorescence after AO/EB staining.The result of cell migration ability showed that cell migration rate gradually decreased with the increased concentration of AVP.The results indicated that MGC-803 cells underwent apoptosis in a dose-dependent manner induced by AVP.Moreover,the western blotting results showed the expressions of bcl-2/bax ratio and VEGF and survivin were decreased in a dose-dependent manner.The results suggested that AVP had a significant anti-tumor activity on MGC-803.