Screening And Hypoglycemic Activity Study Of Polysaccharide CP50 From The Leaves Of Cyclocarya Paliurus

In this study,the crude polysaccharides from the leaves of Cyclocarya paliurus were extracted by water extraction and alcohol precipitation,and the hypoglycemic activity was determined by in vitro and in vi vo experiments.Finally,the basic physical and chemical properties as well as primary structure of crude C.paliurus polysaccharide were analyzed,which aimed to provide a certain scientific basis for the development and industrialization of Cyclocarya paliurus in functional food.The main contents and results are as follows :(1)The crude polysaccharides were purified to obtain purified polysaccharide,and then purified by graded alcohol.Four fractionations were obtained,they are respectively named CP50,CP50,CP70 and CP80.In order to evaluate the in vitro hypoglycemic and antioxidant activity of polysaccharides from Cyclocarya paliurus leaves.The activity of purified C.paliurus polysaccharides and precipitation fractionations of purified C.paliurus polysaccharide obtained from different concentrations of ethanol were compared in this study.The activity of inhibiting ?-glucosidase was used to evaluate the in vitro hypoglycemic effect.The ability of total antioxidant,scavenging DPPH and(·OH)radicals and chelating Fe2 + were used to evaluate the antioxidant capacity.The results showed that purified C.paliurus polysaccharides and different precipitation fractionations all showed a high inhibition against ?-glucosidase.With the ethanol concentration increasing,the fractions obtained showed a higher inhibition activity.Among different precipitation fractionations,the abilities of scavenging DPPH and total antioxidant were increased with the ethanol concentration increasing.In contrast,the abilities of scavenging(·OH)radicals and chelating Fe2 + were decreased.Different C.paliurus polysaccharides have good in vitro hypoglycemic and antioxidant activity,which can be used for further manufacture and exploitation.(2)The chemical properties of the CP50 samples were determined.The cont ents of polysaccharide,protein and uronic acid were 85.37 g/100 g,8.16 g/100 g and 16.23 g/100 g,respectivel y.The structural information of CP50 was anal yzed by amino acid composit ion analysis,mineral element anal ysis,molec ular weight determination and monosaccharide composition analysis.The result s showed that the highest content of amino acids in CP50 were glutamic acid,methionine and aspartic acid.The content of magnesium an d potassium whic h were major elements is high in CP50.Among the trace elements,the content of manganese was the highest,and the content of selenium was the lowest.The molecular weight of CP50 was 85.6 k Da.The CP50 was composed of 5 kinds of monosaccharide,namely rhamnose,arabinose,mannose,glucose and galactose,and the molar ratio was 7.21:7.11:11.94:229.56:34.56.The highest c ontent of monosaccharide is glucose.(3)In this study,we established diabetic mice model induced by STZ to inv estigate th e hypogl ycemic activit y of polysaccharide CP50 in diabetic mice.T he changes of blood glucose,body mass index,the wet weight of immune or gans and the morphological characteristics of islet tissue cells were tested in diabetic mice during the experiment.The results of hypogl ycemic test showed that the different dosage groups of C.paliurus polysaccharide CP50 could si gnificantl y reduce the blood glucose level in diabetic mice,and protect the i mmune organs of mice.Besides,CP50 could aslo increase the we t weight of the kidneys,spleen and kidney,but had no significant effect on the liver.CP50 could promote the recovery of impaired islet cells,and promote the secreti on of insulin.CP50 had no significant effect on body weight change in diabe tic mice.There was no significant difference compared with model group.Glu cose tolerance test showed that the polysaccharide CP50 could increase the tol erance of glucose in normal mice,and the effect of high dose group was sim ilar to that of positive drug metformin.