Effects Of Polypeptide From Phascolosoma Esculenta On Spatial Learning And Memory In Mouse

The extraction condition of phascolosoma esculenta (PE) collagen were optimized by saltmethod and acid extraction method, in order to compare the traditional boiled process of PEcollagen molecular weight distribution. It was concluded that the traditional boiled process of PEcollagen molecular weight distribution was wide, but no specific protein bands. At the same time,we used glutamine transaminase processing PE meat paste, the elastic and viscous of the sampleshave been improved after boiling. The amino acid analysis result showed that, the content ofessential amino acid was high, and glutamic acid content was the highest. Therefore, the sipunculidworm jelly made by PE was delicious and nutritious.PE antioxidative peptide preparation technology were optimized by response surface method.Papain was selected by enzyme filtering experiment as optimum enzyme. Single factorexperiments was designed to determine the enzymolysis time, enzyme amount and ratio of materialto liquid as independent variables, while total antioxidant capacity (T-AOC) resistance as theresponse value. The optimum solutions for PE antioxidant peptide by response surface methodwere listed as below: reaction time was4.28h, and enzyme dosage was3614U/g, and liquid ratiowas1:36. Taking operability into account, the extraction conditions were adjusted to: reaction timewas4.25h, enzyme dosage was3600U/g, liquid ratio was1:36. Under such conditions, thecorresponding T-AOC of the PE collagen peptide was3.8U/mg, and the scavenging ability ofDPPH·was78.25%.We used FeSO47H2O chelated PE polypeptide. The research about PE peptide concentration,pH value of reaction liquid, peptide-ferrous mass ratio on the effects of PE peptide ferrous chelaterate were evaluated. Single factor experiment was designed to determine the best chelatingconditions, and the best selected condition were: peptide concentration was3%, and reaction liquidpH was5, and polypeptide-ferrous mass ratio was3:1. In such conditions, the PE polypeptideferrous chelate ratio was87.98%±0.78%.Gavage administration was chosen to supplement PE polypeptide to mice. The spatial learningand memory of mice was evaluated by Morris water maze test. the PE polypeptide groupsperformed a strong ability of spatial learning and memory, Around the platform quadrant time andtimes of passing through the platform are higher than those of control group during explorationperiod. And there is no much difference between the weight, visual ability and athletic ability ofmice. It prove that PE peptide on spatial learning and memory function is specific, not because of the change of weight, visual ability or exercise capacity. We used RT-PCR to detect the mRNAexpression of NR2A, NR2B, BDNF and CREB subunit expression in hippocampus tissue. Theresults showed that PE peptide can improve mRNA expression of NR2A, NR2B, BDNF andCREB, this result explained that why learning and memory ability of mice increased after lavagedPE polypeptide.