A Therapeutic Effect Observe Of Tibetan Liu Tea Extract On Rats With Alzheimer’s Disease And The Mechanism Research By Proteomics

Objective:To replicate an animal model of Alzheimer’s disease(AD)to observe the therapeutic effect of Tibetan liu tea extract on cortical and hippocampal neuronal injury,and to discuss the mechanism of action of Tibetan liu tea extract in treatment from the perspective of proteomics by comparing the differential expression of related proteins after drug intervention.Methods:The SD rats were randomly divided into 2 groups:Group A(AD model group)and Group B(treatment with Tibetan liu tea extract),according to the random number table.The general states of rats in the 2 groups,such as mental state,fur,feeding behaviour and activities,were observed;Then the pathological sections were examined under optical microscope to observe cortical and hippocampal neurofibrillary tangles,amyloid depositions,neuronal loss and other damages;Finally,the differential expression of proteins in hippocampus of rats was compared between the model group and the treatment group with the technology of proteomics.Results:The rats in Group A exhibited listlessness,fatigue,poor appetite,and rough fur;In contrast,the rats in Group B exhibited restless,flexible behaviour,increased appetite,and smooth fur.Nuclear hyperchromatism,pyknosis,and neuronal loss were observed in the hippocampus and cortex of rats in Group A;Neurofibrillary tangles,amyloid protein deposition and other typical pathomorphological changes in animal brains with AD were also apparent in Group A.On the contrary,the neurons were arranged regularly and densely in the hippocampus and cortex of rats in Group B;Neurofibrillary tangles and amyloid protein deposition were infrequent in Group B.Compared with the model group(Group A),there were eight proteins with high expression and one protein with low expression in the hippocampus of rats in the treatment group,which was detected by the technology of proteomics.According to the mass spectrometry analysis with bioinformatic methods,it can be confirmed that the eight proteins with high expression are respectively Complexin-1,Complexin-2,myelin basic protein(MBP),α-enolase(ENOA),malate dehydrogenase(MDHM).succinate,dehydrogenase complex,subunit B,iron sulfur(SDHB),Synapsin I,Aspartate transaminase;and the one protein with low expression is Keratin,type Ⅱ cytoskeletal 6A(K2C6A).In all of these proteins,Complexin-1,Complexin-2,MBP and Synapsin I were nervous system relative proteins;ENOA,MDHM,SDHB and AATM were metabolism relative proteins;K2C6A was cytoskeletal protein.Conclusion:Tibetan liu tea extract can effectively relieve the symptoms such as neuronal loss,amyloid protein deposition,and neurofibrillary tangles in the hippocampus and cortex of rats with Alzheimer’s disease,and improve the condition of these rats.The results of proteomics research revealed that the expression of multiple proteins,including nervous system relative proteins,glycolytic enzymes,and cytoskeletal protein,changed after Tibetan willow tea extract intervention,which suggested that this drug has a multi-target therapeutic effect and it might be one of the mechanisms in the treatment of Alzheimer’s disease.