| Purpose:Vascular dementia is a type of disease in which brain tissue declines due to vascular infarction or stenosis,which impairs memory function.The elderly are the main population of this disease.Its important symptom is memory impairment.The beginning of the disease will always be accompanied by the entire pathological process.Studies by scholars have found that if intervention can be given in the early stages of VD,it can effectively save patients' lives.The Zhuangyuan Pill comes from "Chi Shui Xuan Zhu" and was created by the medical doctor Sun Yikui in the Ming Dynasty.It is composed of Shichangpu,Polygala spp.,Chishen,Morinda officinalis,Ginseng,and Bone Skin.This project intends to explore the effect and mechanism of Zhuangyuan Wan on memory function in VD model rats.The ZD decoction was applied to VD model rats prepared by a modified two-vessel blocking method,and the Morris water maze was used to test the memory and space exploration capabilities of rats.The degree of white matter damage in rats was observed under microscope,and matrix metalloproteinase 2(MMP2),matrix metalloproteinase 9(MMP9),arginase 1(ARG1),and microglia phenotypic markers were detected by immunoblotting in rat brain white matter.The expression of CD68 was analyzed,and the effect and mechanism of Zhuangyuan Wan on the memory ability of VD model rats prepared by two-vessel occlusion method were analyzed.Method:Forty-eight SPF-grade male SD rats were selected in this experiment and randomly divided into blank group,model group,control group,and treatment group,10 rats in each group.Surgical modeling was performed after one week of adaptive feeding.The piracetam aqueous solution was given,the treatment group was given the decoction of Zhuangyuan Pill,and the dosage was converted according to the body surface area method.The blank group and the model group were given the same amount of normal saline.After 6weeks of continuous administration,the Morris water maze test was performed to analyze the memory ability of the rats.After the experiment,5 rats were randomly selected from each group to fix the brain to prepare paraffin sections.The sections were stained with HE staining and nerve myelin blue staining,and the degree of brain white matter damage in each group was observed under a microscope.The brains of the remaining rats in each group were used to isolate the corpus callosum,and the expressions of MMP9,MMP2,ARG1,and CD86 were detected by immunoblotting.Data were processed using Alpha Ease FC and EXCEL software.All data were expressed using mean ± SD.P <0.05 considered the difference to be statistically significant,and P <0.01 meant the difference was significant.Result:(1)Morris water maze experiment In the five-day directional navigation experiment,it was found that the model group required the longest incubation period.Compared with the model group,the rats in the treatment group had a significantly shorter platform finding time(P <0.01)and were close to the blank group(P> 0.05).Although the learning ability of the control group rats was improved,it was not significantly improved compared with the treatment group.In the space exploration experiment,compared with the blank group,the number of head crossing times of the original platform was reduced in the model group(P <0.05),and the stay time of the original platform was shortened(P <0.01).After drug intervention,the number of crossings increased(P <0.05),the length of stay(P<0.01)increased significantly in the treatment group compared with the model group,and the control group did not change significantly.(2)Morphological observation of brain tissue After HE staining,it was found that the white matter cells in the blank group had complete morphology and clear nuclei.The three groups of rats after modeling had different degrees of white matter damage.Microscopic observation revealed that the model group had the most severe damage and the white matter area had incomplete cell morphology.A large number of vacuoles were seen between tissues,while the vacuole structure of the treatment group was significantly reduced and the cell morphology was more complete than that of the model group.There was no significant difference between the control group and the model group.After observation of nerve myelin sheath blue staining,it was found that the carcass fibers in the blank group were arranged neatly,and the nerve myelin sheath was dark and clear;in the model group,the fiber arrangement was disordered and the nerve myelin sheath was lightly stained.The nerve fibers in the treatment group were arranged more neatly than the model group,and the myelin sheath was darker.(3)Expression of gelatinase in white matter region of brain tissue:Compared with the blank group,the expression of MMP2 in the model group increased significantly.Compared with the model group,the expression of MMP2 in the treatment group decreased significantly.Compared with the blank group,the expression of MMP9 in the model group,treatment group and control group increased,but there was no significant difference in the expression of MMP9 between the three groups.Considering that MMP9 participates in the pathological damage of VD white matter,Zhuangyuan Wan has no significant effect on it The mechanism still needs further research.(4)Expression of polarizing factors in microglia:Six weeks after the modified 2-VO method,the expression of ARG1 in the white matter region of model rats was significantly increased.Compared with the model group,the expression of ARG1 in the treatment group was significantly decreased.The ARG1 expression in the control group also decreased,but there was still a large gap with the treatment group.In addition,M86-type polarizing factor CD86 was significantly up-regulated only in the treatment group.Conclusion:Zhuangyuanwan decoction can effectively treat the cognitive ability and space exploration ability of VD model rats prepared by the improved 2-VO method;it can repair the white matter damage caused by ischemia and hypoxia in brain tissue and improve the demyelination of nerves;Decrease the expression of MMP2 in white matter;decrease the expression of inflammatory factor ARG1 in white matter,increase the expression of CD86,and induce the activation of microglia to M2 type.The Zhuangyuan Pill has a significant effect on improving memory dysfunction in VD model rats. |
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