The Protective Effect Of Radix Astragali Injection On White Matter Lesions In Rat Brain Following Chronic Cerebral Hypoperfusion

Objective The purpose of this study was to investigate the protective effect of Radix Astragali(RA) Injection on White Matter Lesions(WML) in rat brain following Chronic Cerebral Hypoperfusion.The pathological changes on subcortical white matter,performance of learning and memory,and the immunohistochemistrical changes of glial fibrillary acidic protein(GFAP) andβ-amyloid precursor protein (β-APP) were measured in this study.Methods Forty eight Male SD rats weighing 180g to 220g were used in this experiment.Rats were randomly divided into two groups including one-month group and two-month group.Both of the two groups were randomly divided into three subgroups:the sham-operated group,the model group,and the RA group.The model of Chronic Cerebral Hypoperfusion was established by Two Vessel Occlusion(or called 2VO).At 24h after the operation,rats were injected intraperitoneally medicine or normal saline,respectively in different groups.The medicine was injected after operation every other 12h until they were scared at corresponding time points.In the RA group,RA Injection was injected intraperitoneally;while in the sham-operated group and the model group,equally dose normal saline was injected.Morris water maze test was adopted to examine the rats' memory change at corresponding time points after ischemia.Then the rats of one-month group were decapitated after one month of the operation and the rats of two-month group after two months.The rats' brains were removed for histopathological observation and immunohistochemistrical examination.The positive immune reacted cells of GFAP and the positive immune reacted area percentage ofβ-APP to measured-area were counted under light microscope at different time points after ischemia.Results Histopathological examination showed that the demyelination and axonal damage in the RA groups were significantly milder than that of model groups (p＜0.05),but more worse than that of sham-operated groups(p＜0.05) at different time points after ischemia.Compared to that of the model group,the cognitive impairment of RA groups was significantly alleviated(p＜0.05),but still more worse than that of sham-operated groups(p＜0.05).The number of GFAP-positive cells in RA groups was significantly lower than that of model groups(p＜0.05),but higher than that of sham-operated groups(p＜0.05).The positive-area ofβ-APP in RA groups was more smaller in RA groups as compared with model groups(p＜0.05) too,but significantly larger than that of sham-operated groups.Conclusions The RA Injection has protective effect against White Matter Lesions in rat brain following Chronic Cerebral Hypoperfusion:Inhibiting the excessive expression of GFAP andβ-APP might be the mechanisms of the protective effect of RA Injection..