Study On Antioxidation And Hypolipidemic Of Glycosaminoglyan From Paphia Undulate

Paphia undulata is a kind of seashell, which is rich in resources and widely spread over South China Sea. The study used Paphia undulata as raw material, having done systemic research on the extraction,isolation and purification of glycosaminoglycan from Paphia undulate,then analyzing and determining its chemical compositions. On the basis of the fundamental research on glycosa-minoglycan from Paphia undulate, the experiment method of antioxidation and hypolipidemic were primarily studied to investigate the glycosaminoglycan activity. The results would provide theoretical basis for the exploiting and utilizing Paphia undulate, which also could establish academic and experimental basis for food or pharmic exploitation.The paper mainly includes the following four parts:1.To optimize the method extraction of glycosaminoglycan(GAG)from Paphia undulate:on the base of the single factor investigation, the ratio of water to material,the enzymolysis time, the enzyme dosage were studied with the central composite design and their interactions on the yield of GAG were also investigated. The predictive polynomial quadratic equations model was developed by SAS software and response surface analysis. Optimal conditions of the enzymatic method of GAG from Paphia undulate can be concluded as follows:the ratio of purified water to material 2.5:1,the enzymolysis time 3.5h, the enzyme dosage 1 (g/100g). On these conditions, the yield of PUG is up to 0.413%.2. PUG was extracted by the optimal conditions, The removal of protein in the product was compared by different pH values,and then membrane filtration and desalination was used to prepare PUG-1. The DEAE-52-cellulose ion exchange chromatography was applied to further purify the PUG-1, it was separated into two fractions(PUG-1a, PUG-1b). PUG, PUG-1, PUG-1a, PUG-1b were composed of glycogen 16.4%,19.2%,25.4%,22.4%; gross protein 28.7%,19.8%,10.3%,9.4%; glycosaminoglycan 31.4%,46.7%,68.3%,62.8%; sulfate 3.3%,5.6%,11.5%,15.2%; galactosamine 3.4%,5.7%,10.7%,12.5%; glucuronic acid 9.5%,7.7%,15.2%,13.7%; hexosamine 13.3%,20.6%,31.7%,35.1%.Molecular weight of PUG-1a and PUG-1b were determined by HPSEC.The result indicates their average moleeular weights are estimated to be 30000Da and 10000Da. Characteristic groups and structure of PUG-1a, PUG-1b IR were determined by IR. The result of IR showed that PUG-1a,PUG-1b had diffrernt characteristic groups and structure, PUG-1a had pyranose; PUG-1b had more sulfate,carboxyl andα-glucoside bond;These were characteristic of glycosaminoglycan.3.The in vitro antioxidant properties of the glycosaminoglycan were tested by using the capacity to scavenge-OH,O2-·,DPPH as indicators.The results showed that the maximal inhibition rate of·OH exceeded 55.4% was given at the concentration of PUG-1 6mg/mL; The experiment also showed that the activities and amounts of PUG,PUG-1 below 5 mg/mL were relative. The highest scavenging effect of O2-·could reach 68.7%;It was proved by the test that that PUG is effective in seavenging DPPH, The best capability to scavenge DPPH was at the concentration of PUG-1 7mg/mL. So PUG and PUG-1 have powerful activities to scavenge ROS.Antioxidation effect in vivo of PUG-1:Aged mice caused by D-galactose were perfused with 100,200 and 400mg/kg.d PUG for 4 w, the effect of PUG-1 on the content of superoxide dismutase(SOD),Glutathione pero-xidase(GSH-Px),malondialedhyde (MDA), catalase (CAT) in serum, liver and brain were observed.The results showed that PUG-1 had no obvious effect on mice weight,the activities of SOD and CAT in serum of middle and high dose aging mice were were signifycantly increased (P<0.01); The activity of SOD, GSH-Px and CAT in serum, liver and brain of high dose were signifycantly increased (P<0.01).The content of MDA of low, middle and high dose were lower than model group (P<0.05).PUG-1 has antioxidant effect in aging mice and showed dose-and-effect relationship.4.The experiment method of the preventive hyperlipemia animal model were applied to investigate the hypolipidemia activity of PUG-1, which was divided into three doses 100, 200,400 mg/kg·d,simvastatin was chosen as standard indicators.After 4 weeks he content of TC, TG, HDL, LDL and AI were observed.The results were follows:; the middle-dose and high-dose groups can remarkably decrease TC,TG and LDL(P<0.01); the two groups could also increase HDL(p<0.05). The results showed that thePUG-1 can obviously inhibit the rising of blood lipid,effectively prevent the hyperlipemia and arterisclerosis damages.