Study On Preparation And Antioxidative、Hepatoprotective Effects Of Polysaccharides From Agaricus Blazei Murill

Agaricus blazei Murill is a kind of mushroom used for both food and medicine, and it has various strong biological activities of anti-tumor, strengthening immunity, anti-mutation, anti-viral and hypoglycemic activities, etc. Agaricus blazei Murill has winned warm praise because of its sweet flesh, excellent medication and health value. The content of polysaccharides extracted from Agaricus blazei Murill ranked first among the edible fungi, with high development prospect in the medical field and health care industry. However there is few researches and reports about its hepatoprotective effects. In this research, we conduct Agaricus blazei Murill as raw materials, via ultrafiltration to obtain grading polysaccharide, the focus is mainly on the antioxidant activity and hepatoprotective effect of polysaccharides to chemotherapy liver injury of mice which been inducted by GalN.1、The reserch showed that the polysaccharides extracted from the Agaricus blazei Murill handle were much higher than that of the Agaricus blazei Murill umbrella. The optimum conditions of extracting water-soluble polysaccharides from Agaricus blazei Murill were performed by central composite design experiment and response surface analysis (RSA) as follows:extraction temperature of 100℃, time of 3.36h and water-material ratio of 1:20, under which the highest yield of polysaccharides reached with estimated value and verified value being of 8.727% and 8.718%, respectively.2、The deproteinization of Agaricus polysaccharides was operated by the method combined with papain-Sevag, this method had good effect of removing protein and polysaccharides loss was small, much better than Sevag method alone. The polysaccharides of Agaricus blazei Murill were separated with ultra-filtration, experiment results showed that the optimum operating conditions were that the concentration of polysaccharides was controlled below 30mg/mL (100kDa)、25mg/mL (10kDa), 20℃-30℃, the pH 7-8, the ultrafiltration pressure 0.08MPa. The polysaccharides was separated into three components (>100kDa, lOkDa-100kDa and<10kDa) according to their molecular weight(MW) by ultra-filtration, whose mass distribution is 2.36:1.17:1, and the recovery ratio of the polysaccharides was 79.16%.3、Compositiuon analysis showed that, the polysaccharides extracted from Agaricus blazei Murill were neutral polysaccharides, and contained no uronic acid. Physical-chermistry analysis demonstrated that, Agaricus blazei Murill polysaccharides were all non-starch polysaccharides without polyphenols. GC showed that ABMP1、 ABMP3 were mainly composed of glucose. ABMP2 consist of fucose, mannose, glucose and galactose, the molar ratio of them was 1:1.02:6.69:4.40.4^ The results showed that anti-oxidation activity of polysaccharides from Agaricus blazei Murill was strong. And antioxidant activity of ABMP1、ABMP2 and ABMP3 were compared in different reaction systems. The ABMP2 with an MW between lOkDa-100kDa had the strongest activity, so it was selected as the research object of follow-up experiment.5、The hepatoprotective effects of ABMP、ABMP2 against GalN-induced liver damage in mice were investingated. Compared with model group, ABMP、ABMP2 could obviously reduce the indexes of liver and spleen. The activities of AST and ALT, and the content of MDA could be down-regulated; the content of GSH could be increased. The hepatocyte damage could also be improved which could be evidenced by the liver slice. The degree of hepatic injury could be lessened. ABMP2 did better than ABMP on hepatoprotective effect. And high dose of ABMP2 had the most effective hepatoprotective against GalN-induced liver damage in mice. The mechanism of hepatoprotective effect needs further study.