Effect Of Polygona-polysaccharose On Learning And Memory Ability In Alzheimer's Disease Rats And Apoptosis Of Hippocampus Cells

Alzheimer's disease (AD) is one of the highest incident and most dangerous neural degenerative diseases of the central nervous system in the elderly,also is the most common form of senile dementia. It's characterized by progressive memory loss and cognitive impairment, disordered behavior ,and lack of language skills leading to dementia and finally death. The pathological hallmarks of which include extracellular senile plaques(SP) aggregates and intracellular neurofibrillary tangles(NFTs) composed of hyperphosphorylated microtubular protein tau and loss of neurons .There has been no definite explanation to the mechanism of AD so far. The lack of an ideal animal model of AD is also constraining scientific research and drug development. With the rise of world's average life expectancy,the incidence of senile dementia is increasing. Therefore, the basis and clinical research of the disease has important clinical significance and social significance.Modern pharmacological studies proved that Polygona- Polysaccha-rose (PP) can anti-aging,enhance immunity, degrade the level of lipid peroxidation, low blood sugar and lipid, anti-tumor, antibacterial and anti-virus and so on. At present,the study of the pharmacological is becoming further. ObjectivesTo establish experimental animal model in accord with the praxiological and pathological characteristics of AD; To investigate the effect and function of Polygona-Polysaccharose(PP) on learning and memory ability in Alzheimer's disease rats and apoptosis of hippocampus cells.MethodsA total of twenty male Sprague-Dawley rats were divided into three groups,Sham-operated group(NSgroup), model group(Aβgroup), intervention group (PPgroup). Inject Saline into Sham-operated group (NSgroup)'s hippocampus and inject Aβ_1-42 into other two group to establish AD animal model. Inject 16% PP solution into the intervention group (PPgroup) 's stomach for 45 consecutive days and other two groups with Saline. The Morris water maze were employed to investigate ability of learning and memory in rats. The sections of the brain were examined with HE staining to observe the organizational structure,the Methyl-alcohol-Congo staining to observe the aggradation of Aβ,the TUNEL to detect the number of apoptosis neuron in hippocampus. To observe the effect of Aβand Polygona-Polysaccharose toward above-mentioned indexes. Results1.Learning and memory ability: Compared with the model group(Aβgroup),the escape latency of the intervention group(PPgroup) shortened obviously, the way of looking for platform changed,the number of times of crossing the platform and the percentage of time spent on crossing the target quadrant to the total swimming time increased. These all have statistical significance.2.Morphology change of hippocampus:The Sham-operated group(NS group) have no significant change; The morphology and permutation of hippocampus cells of the intervention group(PPgroup) are basicly normal. Olny can find a little degeneration cells. The methyl- alcohol-Congo staining can find the aggradation of positive staining materials; The model group(Aβgroup) decreased in the layer of pyramidal cells,the cells arranged sparse and irregular and become smaller,also can find karyopyknosis and vacuolar degeneration cells. The methyl- alcohol-Congo staining can find many more positive staining materials aggradated compared with the model group(P<0.05).3.The number of TUNEL positive neuron in hippocampus of the intervention group(PP group)is obviously fewer than the model group(Aβgroup).The difference between the two groups is statistically significant(P<0.01). Conclusions1 .The infused Aβin the hippocampus is related to the impairment of learning and memory and the neuronal degeneration in the rats which showed similar behavior and pathological characterizations of AD.This Aβinfused rats could be used as an animal model for AD .2. Polygona-Polysaccharose(PP) can reduce the deposition of Aβin the hippocampus and significantly improve the ability of learning and memory of AD model rats.3.Polygona-Polysaccharose(PP) can reduce apoptosis of hippocampus cells of AD model rats.