Study On The Functional Properties Of Cucurbit Moschata Duch Polysaccharides And Its Possible Mechanism Of Hypoglycemic Effect

Pumpkin （Cucurbit moschata Duch.）, the fruit of the CucurbitaceaePumpkin, is a fairly rich resource in China, its therapeutic role in health care has beenrecorded since in ancient China. In recent years, there is a lot of animal studies andclinical researches on the prevention and treatment of diabetes of pumpkinpolysaccharide, deepening the mechanisms for the prevention and treatment ofdiabetes. But it is still unclear about the pumpkin polysaccharide absorption into thebody distribution law, so as the degradation of metabolic pathways in various parts ofthe gastrointestinal tract, especially the correlation of the pumpkin polysaccharide toimprove oxidative stress and hypoglycemic. This paper used pumpkin as rawmaterial, by preparing the hypoglycemic activity of pumpkin polysaccharide,simulating its real peristaltic changes in the artificial gastric juice, to gain the reliableinformation of pumpkin polysaccharide after the stomach action; Purifiedhypoglycemic pumpkin polysaccharide to collect the homogeneous components,preparing the fluorescent derivatives of pumpkin polysaccharide and establishing thequantitative analysis method in biological samples, to prove the pumpkinpolysaccharide absorption distribution pattern in mice; Exploring the pumpkinpolysaccharide hypoglycemic mechanism in different ways; Analysising thewater-insoluble functional properties of pumpkin polysaccharide. The main resultsare as follows.1This paper use Sevage method to remove the protein from the hydroalcoholicextract to prepare the water-soluble pumpkin polysaccharide （PP）. Testing theeffection on alloxan diabetic mouse model to verify its hypoglycemic effect. Theresults of dynamic process by simulating PP in vitro artificial gastric motility modelshows PP in vitro simulated gastric conditions will occur over time role a certaindegree of degradation, resulting in reducing sugar and oligosaccharide fragmentshydrolyzate still has significant hypoglycemic effect, and the role hydrolyzate after150min has highly hypoglycemic effect than the one after30min. 2Preparing different particles of the water-insoluble pumpkin polysaccharide（IDF）, testing the combination of hydro, adsorption properties （including oil retention,bile salts, cholesterol, nitrite ion adsorption capacity）, cation exchange capacity, theresults shows the IDF combination of hydraulic trend increase first and then decreasewith decreasing particle size, the fine powder has the strongest binding capacity, therewas a significant difference （P<0.05）. The ability of sodium cholate combined intandem with decreasing particle size appears first increase and then a downward trend,but there is no significant difference among the particle size （P>0.05）. The cholesteroladsorption capacity changed little with decreasing particle size （P>0.05）, but therewas a significant difference （P<0.05） in pH2and pH7. The oil holding force,adsorption of NO^2-capacity and cation exchange capacity downward trend withdecreasing particle size, the coarse powder has the strongest effect.3Classificate four components （PP-a,-b,-c,-d） of pumpkin polysaccharide（PP） by using different concentrations of alcohol, and then analysis the hypoglycemiceffect and yield of each components. The high yield and a significant hypoglycemiccomponent PP-c was separated and purified into two different molecular weights ofcomponent （PP-e,-f） by gel column. PP-e, molecular weight4630Da, has thesignificant hypoglycemic effect and last longer. Rhamnose, arabinose, glucose andgalactose is as a mainly structural unit, the molar ratio is1.12:5.19:1.00:3.91.4PP-e-flu can be obtained by marked fluorescent to pumpkin polysaccharide,tracing the PP-e-flu in the tissues and organs of the gastrointestinal tract in mice bytwo routes of intragastric administration and intraperitoneal injection afterestablishing a quantitative analysis method of the PP-e-flu in a biological sample. Theresult turns out that the jejunum and ileum of the small intestine are the major area ofabsorption in mice after intragastric administration. The absorption time is mainlyconcentrated in1h to6h. PP-e-flu is detected in the liver30min after intragastricadministration, and then rising to top at24h after intragastric administration.Detected in the spleen and pancreas6h after intragastric administration, and thenrising to top at24h after intragastric administration. In the mode of administration ofintraperitoneal injection, PP-e-flu cound be detected in stomach, small intestine（duodenum, jejunum, ileum） and large intestine （cecum, colon）, rising slowly to thetop level at6h, and then declines, stabilized from12h to24h. The highest content ofPP-e-flu was detected in jejuna, two times as high as the others. PP-e-flu cound not bedetected in the liver. Detected in spleen, rise slowly to peak after60min, followed bya slow decline to zero after12h. PP-e-flu was detected in pancreas at30min, hadbeen rising up to the highest value after12h, and maintain to the24h.5Explore the possible hypoglycemic effect mechanism of pumpkinpolysaccharide by different experimental hyperglycemia model blood glucose in mice,the influence of pumpkin polysaccharide on alloxan diabetic mouse pancreatic andliver tissue cells and in vitro and in vivo antioxidant activity of pumpkin polysaccharide. The result turns out that pumpkin polysaccharide can significantlyinhibited （P<0.01） blood sugar of alloxan-induced diabetic mice. Reduce the bloodglucose （P<0.01） of adrenergic model mice so as the dexamethasone-induceddiabetic mice. Pumpkin polysaccharides had significantly effect （P<0.05） onincreaseing the pancreatic insulin levels of alloxan-induced diabetic mice, recoveringthe hepatic glycogen to normal levels, repairing damaged islet tissue and liver tissuecells. Significantly increased （P<0.01） superoxide dismutase, catalase form the serumand liver tissue. Significantly decreased （P<0.05） malondialdehyde （MDA） and NOfrom liver tissue.