Preparation Of Boletus Copperi Polysaccharide And Its Antitumor Activity In Mice

Edible fungus polysaccharides have a variety of biological activities,their antitumor activity has been studied extensively.Tumor diseases seriously endanger human health,but current chemotherapy drugs have obvious side effects.Therefore,it is important to find a natural substance that has anti-tumor activity and can reduce the side effects of chemotherapy drugs.In this research,a water-soluble polysaccharides（BAP）was extracted from Boletus aereus,and its physical and chemical properties and antioxidant activity to explored.Further,through animal experiments,S180tumor-bearing mice were used as a model to study the combination of BAP and anti-tumor drugs（cyclophosphamide,CTX）in vivo.Finally,BAP was separated and purified,and its structural characteristics were analyzed.The main research contents are as follows:1.The single factor experiment（extraction time,temperature and material-liquid ratio）was used to study the extraction of BAP,and BAP was prepared under the best conditions.The results showed that the best conditions were the extraction temperature of 50℃,the extraction time of 4 h,and the ratio of material to liquid of1:40（w/v）,the extraction rate of BAP was 15.76±0.03%under the best conditions.2.Research showed that the total sugar and protein content of BAP was 55.35%and 16.78%,respectively,and BAP contained a little of uronic acid and reducing sugar;BAP was mainly composed of mannose,glucose,galactose and fucose in a molar ratio of 1.38:4.7:1.6:1;FT-IR analysis indicated that BAP might be a pyran polysaccharide linked byαandβglycosidic bonds.3.The antioxidant experiments in vitro showed that the IC₅₀values??of BAP’s scavenging activity on·OH、DPPH·、ABTS⁺·was 307.43,92.78,41.48μg/m L,respectively.The EC₅₀value of iron reduction ability was 38.67μg/m L of BAP.In addition,BAP has good gel properties.4.The anti-tumor activities of BAP and/or CTX were investigated using the model of S180 tumor-bearing mice.BAP could effectively suppress the growth of S180 solid tumor and protect the immune organs of mice.BAP could increase the level of spleen cytokines on S180 tumor-bearing mice,and the distribution of T lymphocyte subsets.H&E staining,Annexin V-FITC/PI double staining and the JC-1staining demonstrated that BAP could induce the apoptosis of S180 tumor cells.BAP and CTX had a significant synergistic anti-tumor effect on S180 cells in vivo,and alleviate the side effects of CTX.5.Three fractions were separated from BAP through DEAE-Cellulose-52 column and Sephadex G-100 gel column.All three fractions were heteropolysaccharides and they had similar monosaccharide composition,all of these were composed of mannose,glucose,galactose and fucose,but the composition ratio was different.There were no absorption peaks at 260 nm and 280 nm on UV spectrum,indicating that there were no nucleic acid and protein on these three fractions,FT-IR and NMR analysis demonstrated that they was a pyranose withα-type andβ-type glycosidic residues.