Study On The Effect And Mechanism Of Yuanzhi And Yuanzhi Oligosaccharide Ester In The Improvement Of Cognitive Function By Qiuxin Powder

Alzheimer's disease(AD)is the most neural degenerative disorder which characterized by progressive memory loss and cognitive impairment.The pathological hallmarks of which include senile plaques(SPs),amyloid ?(A?),Tau protein hyperphosphorylation,neurofibrillary tangles(NFTs)formation,cholinergic function and neural loss.There has been no definite explanation to the mechanism of AD so far,thus delay the progression of AD and improve cognitive function is a hotspot in the research of drug.Kai Xin San(KXS)was first appeared in<Qianjin Yaofang>by Sun Simiao in Tang dynasty.KXS is composed of polygala,ginseng,poria and calamus which have a wide range of pharmacological effects particularly in promoting intelligence,anti-aging and anti-oxidantion.But until now we have not found the evidence on cognitive dysfunction of APP/PS1 double transgenic mice,therefore we cannot clarify the exact role of KXS in anti-AD and related targets.Study has found that the main components of KXS in intestinal absorption liquid and drug-containing serum are polygala oligosaccharide esters and KXS has a relationship with polygala in antioxidantion in vitro.Polygala can tranquilize the mind and promote the intelligence and has the effect of improving learning and memory in a variety of AD animal models.Polygala oligosaccharide esters also have neuroprotective effects,thus we presume polygala and polygala oligosaccharide esters may play an important role in anti-dementia in KXS.This paper was to study the effect of KXS on cognitive disorder on APP/PS1 double transgenic mice in behavioristic,pathological morphology,CREB phosphorylation level,BDNF protein expression,A? deposition,Tau protein hyperphosphorylation and other aspects and explore the role of polygala and polygala oligosaccharide esters in KXS.Part I:The improving effect of KXS?KXS without polygala and polygala oligosaccharide esters on APP/PS1 double transgenic miceThis part we use APP/PS1 double transgenic mice as object study,by oral administration KSX,KXS without polygala and polygala oligosaccharide esters once daily for 4 months continuously.By using Morris Water Maze and step-down test we can observe learning and memory ability of APP/PS1 mice.The pathological changes in the hippocampus were observed by HE staining,Nissl staining and transmission electron microscope.The results show that in the Morris Water Maze training,on the fifth day,compared with the normal control mice,the latency of finding the platform of APP/PS1 double transgenic mice extended by 20%.Compared with APP/PS1 double transgenic mice,the latency of finding the platform of positive drug donepezil(0.75mg/kg)mice was extended by 20%.KXS low dose(1.5g/kg)made the latency of finding the platform of APP/PS1 double transgenic mice extend 33%.KXS without polygala high dose(2.6g/kg)made the latency of finding the platform of APP/PS1 double transgenic mice extend 13.6%.Polygala oligosaccharide esters low dose(0.05g/kg)made the latency of finding the platform of APP/PS1 double transgenic mice extend 13.5%.In the withdraw platform test,compared with the normal control mice,the first time of APP/PS1 double transgenic mice crossing the platform was significantly longer(P<0.05),the times of crossing the platform in the 90s were significantly fewer(P<0.05).Compared with APP/PS1 double transgenic mice,KXS high dose(3g/kg)could significantly shorten the first time of APP/PS1 double transgenic mice crossing the platform,increase its crossing platform times(P<0.05).KXS low dose(1.5g/kg)could significantly shorten the first time of APP/PS1 double transgenic mice crossing the platform(P<0.05),which also increased the times of crossing the platform,but there was no significant difference.KXS without polygala high doses(2.6g kg)could shorten the first time of APP/PS1 double transgenic mice crossing the platform(P<0.05).In the step-down test,compared with the normal control group,the step-down latency of APP/PS1 double transgenic mice significantly decreased(P<0.01),the number of step-down errors within 5min increased significantly(P<0.01).KXS low dose(1.5g/kg)could significantly prolong the APP/PS1 double transgenic mice step-down latency(P<0.01),and reduce the number of step-down errors(P<0.01).KXS without polygala high,low dose(2.6g/kg,1.3g/kg)and polygala oligosaccharide esters high and low dose(0.1g/kg,0.05g/kg)also could prolong the APP/PS1 double transgenic mice step-down latency,reduce the number of step-down errors,but had no significant difference.HE staining and Nissl staining showed that the arrangement of hippocampal neurons in APP/PS1 double transgenic mice was disordered,the number of neurons was reduced and the nuclear was enriched.These changes were reversed by oral administration KXS,KXS without polygala and polygala oligosaccharide esters to some extent.Furthermore,by using the transmission electron microscope we found that KXS,KXS without polygala and polygala oligosaccharide esters could protect against the disorder of neurons,ribosome,endoplasmic reticulum,Golgi's complex and mitochondria in APP/PS1 double transgenic mice.These results suggest that KXS can attenuate learning and memory disorders and pathological changes in the hippocampus of APP/PS1 double transgenic mice.The effects of KXS without polygala were much weaker than KXS,indicating that polygala may be the important ingredient involved in the improvement of KXS on the learning and memory disorders.Polygala oligosaccharides esters may also have a role in improving the pathological damage,but not significantly in learning and memory disorder,suggesting polygala oligosaccharides esters may have a synergistic effect with other components.Part ?:The mechanism of KXS,KXS without polygala and polygala oligosaccharide esters in improving APP/PS1 double transgenic mice cognitive functionThis part we use preceding administration,by using immunohistochemistry method to detect the level of Tau protein hyperphosphorylation and A?production in APP/PS1 double transgenic mice cerebral cortex.Using Western Blot test to detect the expression level of p-CREB,CREB,BDNF in APP/PS1 double transgenic mice hippocampus.Using TEM experimental method to detect the changes of synapse structure in the APP/PS1 double transgenic mice hippocampal CA1 regionBy immunohistochemical method we found that compared with the normal control group,the abnormal phosphorylation of Tau protein increased significantly(P<0.01),the level of A?increased significantly(P<0.01).Compared with APP/PS1 double transgenic mice,positive drug donepezil(0.75mg/kg),KXS high and low dose(3g/kg,1.5g/kg),KXS without polygala high dose(2.6g/kg),polygala oligosaccharide esters high and low dose(0.1g/kg,0.05g/kg)could significantly decrease the abnormal phosphorylation level of Tau protein,and reduce the production of A?(P<0.05,P<0.01).By Western Blot method we found that compared with normal control group.p-CREB/CREB ratio of APP/PS1 double transgenic mice had a decreased trend,and the level of BDNF decreased significantly(P<0.05).Compared with APP/PS1 double transgenic mice,positive drug donepezil(0.75mg/kg),KXS low dose(1.5g/kg)and polygala oligosaccharide esters low dose(0.05g/kg)made p-CREB/CREB ratio appear an increasing trend,and BDNF protein level significantly increased(P<0.05).The results of the TEM experimental method showed that compared with the normal control group,the number of synapses and the curvature of synaptic interface decreased,the synaptic gap width increased,the thickness of postsynaptic dense zone reduced significantly(P<0.01)in hippocampus of APP/PS1 mice.Compared with APP/PS1 double transgenic mice,positive drug donepezil(0.75mg/kg),KXS low dose(1.5g/kg)and polygala oligosaccharide esters low dose(0.05g/kg)could increase the number of synapses and the curvature of synaptic interface,decreased the synaptic gap width and increased the thickness of postsynaptic dense zone(P<0.01).Based on these results above,we speculate that the effects of KXS on improving learning and memory impairment of APP/PS1 mice may be related to the increase of expression of BDNF,reduction of A? deposition and abnormal phosphorylation of Tau protein and improvement of synapse structure.The effects of KXS without polygala were weaker than KXS,and polygala oligosaccharide esters also had some improvement,thus we speculate KXS without polygala and polygala oligosaccharide esters paly an important part in improving learning and memory in KXS.