Evaluation And Mechanism Of The Improvement Of Memory By Sea Cucumber (Stichopus Japonicus) Peptides

With the rapid development of modern society,it makes us live more convenient,and it also brings some new problems,such as anxiety insomnia and memory loss.Therefore,it may be a research hotspot to product an efficient cheap peptide nutrition supplement with the function of enhancing memory.In this paper,bioactive peptides that might help improve memory were selected from sea cucumber peptide,oyster peptide,pea peptide and corn peptide.Based on that,this research evaluates different doses of sea cucumber peptide to enhance memory through non-impairment memory model and memory damage model induced by scopolamine.Based on the animal experiment,the different protein modification and histomorphological changes of hippocampal histones reveal the mechanism of the improvement of memory by sea cucumber peptide.Latency time of sea cucumber peptide was 12.60±2.41 s,the number of errors was 2.25±0.50 times,and the number of electric shocks was 5.50±0.71 times,which were smaller than the control group.The MDA in the liver tissue homogenate of the sea cucumber peptid was 1.7±0.52nmoL/mL,which was lower than the control group.The SOD was 9.25±0.96U/mg,and the GSH-PX was 4018.76±598.23U/mg,which was higher than the control group.The AChE of the brain tissue homogenate of the sea cucumber peptide group was 1.63±0.13 U/mg,which was lower than the control group.The result of sea cucumber peptide are more significant and it can help improve the memory of mice.The latency time of low dose sea cucumber peptide(0.65mg/(g·d))was 20.11±1.79 s,which was smaller than the control group.The body weight,daily food intake and daily water intake of the mice in each experimental group were no significant difference(P>0.05).The result of low-dose group of sea cucumber peptide were significant,indicating that the low-dose sea cucumber peptide improved the memory of mice.The latency time of low dose sea cucumber peptide(0.65mg/(g·d))was 15.57±1.36 s,and the number of electric shocks was 4.00±0.68 times,which was smaller than the control group and other groups.The AchE of low dose sea cucumber peptide was 0.17 ± 0.04U/mg,which was smaller than the control group The body weight,daily food intake,daily water intake and organ coefficient of the mice in each experimental group were no significant difference(P>0.05).The result of low-dose group of sea cucumber peptide were significant,indicating that the low-dose sea cucumber peptide improved the memory of mice.The Ach of low dose sea cucumber peptide was 18.46±1.94?g/mg,which was smaller than the control group.Compared with the control group,the level of acetylation in the hippocampus of the model group was decreased,and the level of acetylation in the hippocampus of the low-dose group of sea cucumber was increased.The low dose of sea cucumber protein peptide can improve the memory by increasing the content of acetylcholine(Ach)in the brain and increasing the level of acetylation in the hippocampus.Compared with the control group,the number of neurons on the hippocampal pyramidal cell of the model group was decreased,which showed that the cell volume was narrowed and the nuclear membrane was unclear,and the nucleus and cytoplasm were concentrated and deeply stained.The neurons are loosely arranged,and the neurons are small and unclear.The hippocampus neurons in the low-dose group of sea cucumber were rich in neurons,arranged neatly,complete morphology tight cells and wide cell bands.Compared with the control group,the brain cortex,liver,colon and kidney cells of each test group were well-formed,neatly arranged,uniform in size,and clearly defined,with no significant differences.The sea cucumber peptide at low dose can increase the number of hippocampal pyramidal cells of mice to improve memory and different doses of protein peptide have no toxic effect on mice.