Extraction,Sulfation Modification Of Poria Cocos Polysaccharide And Its Inhibitory Effect On The Proliferation Of Gastric Cancer Cell MGC 803

Background:Poria cocos,as one of the Chinese medicinal materials with the same origin as medicine and food,is rich in polysaccharides,triterpenes,diterpenes,sterols,volatile oils and other active compounds.Among them,polysaccharides are the main active compounds that exert pharmacological effects,and have pharmacological effects such as antioxidant,anti-tumor,immune regulation,liver protection and hypoglycemic.Due to the low biological activity of many natural polysaccharides,it is particularly important to modify the polysaccharide molecule to change its structure and conformation to enhance its biological activity.Objective:To use ultrasonic-microwave synergistic assisted extraction of Poria cocos polysaccharide and obtain the optimal extraction conditions,and to investigate the inhibitory effect of Poria Cocos polysaccharides（PCP）and its sulfated derivatives on the proliferation of gastric cancer MGC 803 cells by preparing sulfated Poria cocos polysaccharides.Influence.Methods:（1）Single factor and orthogonal optimization experiments were used to explore the optimal extraction conditions for ultrasonic-microwave synergistic extraction of Poria cocos polysaccharides;（2）Sevage method was used to deproteinize Poria cocos polysaccharides,and then sulfur trioxide-pyridine was used to deproteinize Poria cocos polysaccharides.The polysaccharides were modified by sulfation method;（3）By examining the scavenging ability of DPPH·radicals,·OH radicals,ABTS·radicals,O₂^-·radicals,the in vitro resistance of PCP and sulfated derivatives was studied.（4）CCK-8 method,scratch test,hoechest 33342 staining test and Annexin V-FITC/PI double staining method were used to study the inhibitory effect of PCP and sulfated derivatives on the proliferation of gastric cancer cells MGC Results:（1）Ultrasound-microwave synergistic assisted extraction of Poria cocos polysaccharide optimal extraction conditions:extraction time 10 min,liquid-to-solid ratio 1:40,ultrasonic power 150 W,microwave power 200 W;（2）PCP-S1 obtained by sulfation modification,PCP-S2,PCP-S3 three kinds of sulfated Poria cocos polysaccharides,the degree of substitution of 0.29±0.03,0.41±0.07,0.66±0.05,and using infrared spectroscopy,scanning electron microscopy for structural characterization,indicating that the sulfated Poria cocos polysaccharide derivatives were successfully obtained（3）The in vitro antioxidant results showed that PCP had the best scavenging effect on ABTS·radicals,followed by DPPH·radicals,while the scavenging ability of·OH radicals and O₂^-·radicals was relatively poor,and Compared with PCP,the three sulfated derivatives had better antioxidant capacity in vitro,and the clearance rate increased with the increase of substitution degree;（4）Poria cocos polysaccharide and its sulfated derivatives had better effect on gastric cancer MGC 803 cells.The proliferation has a significant inhibitory effect in a concentration-dependent manner,and increases with the degree of substitution.It can weaken the migration ability of gastric cancer MGC 803 cells and promote cell apoptosis.Conclusion:1.The sulfated modified Poria cocos polysaccharide enhanced its antioxidant activity in vitro,and the clearance rate increased with the increase of substitution degree.2.Poria cocos polysaccharide and its sulfated derivatives have a significant inhibitory effect on gastric cancer MGC 803 cells,can promote their apoptosis,can attenuate the migration ability of gastric cancer MGC 803 cells,and the sulfated modified Poria cocos polysaccharide enhances its anticancer effect activity,and the anticancer activity increases with the degree of substitution.