Neuroprotective Effect Of Modified Dihuang Yinzi On Vascular Dementia Model Rats

Objective: By observing the effects of modified Dihuang Yinzi on behavior,pathological morphological changes in the hippocampal CA1 and cortical regions,inflammatory factors,neurotransmitters,cerebral blood flow,apoptosis rate in the hippocampal CA1 region,and PI3K/Akt signaling pathway in VD model rats,the neuroprotective effect of modified Dihuang Yinzi on VD model rats was investigated.Methods: 84 SD male rats,random 12 only as control group,only exposed bilateral common carotid arteries ligation,the remaining 72 rats using only Two vessels block(Two vesssl occlusion,2-VO)of Vascular dementia(Vascular dementia,VD)model rats,the stroke index and nerve symptom scores,screening,60 Cheng Mo rats were randomly divided into model group,nim horizon group(0.011 g/kg),rehmannia Yin Zi add and subtract the high,medium and low dose group(4.54,2.27,1.14 g/kg),12 mice in each group were given by gavage at the 4th day after modeling,and 10 ml/kg of equal volume solvent was given to the sham operation group and the model group,once a day for 30 consecutive days.At the end of treatment,the changes in the characteristics of the rats were observed.The cognitive ability of the rats was measured by stroke index,neurological symptom score and Morris water maze.The pathological changes of hippocampus CA1 and cortex were observed by hematoxylin-eosin(HE).The ultrastructure of CA1 region of hippocampus was observed by transmission electron microscope.The levels of interleukin-6(IL-6),interleukin-1(IL-1β),tumor necrosis factor beam(TNF-α),acetylcholine(Ach)and dopamine(DA)in brain homogenate were determined by ELISA.The changes of cerebral blood flow were detected by speckle.The apoptosis rate of cells in the hippocampal CA1 region was detected by staining in situ apoptosis assay(TUNEL).The expression of phosphatidylinositol 3 kinase(PI3K),serine threonine kinase(Akt)and cysteine aspartate protease 3(caspase-3)in CA1 region of hippocampus was detected by immunohistochemistry.Result:1.Characterization changes in ratsIn the model group,the rats were depressed,ptosis,slow reaction,decreased activity,and less food and drink.The symptoms of rats in each group were relieved.2.BehaviorAfter modeling,the stroke index and neurological symptom score of 60 VD model rats were significantly increased compared with the sham operation group(P<0.01).After 30 days of administration,compared with the sham operation group,the stroke index and neurological symptom score of rats in the model group were significantly increased(P<0.01),the escape latency period was significantly prolonged(P<0.01),and The Times of crossing the effective area were significantly reduced(P<0.01).Compared with the model group,the stroke index and neurological symptom score of rats in each drug administration group were significantly reduced(P<0.05,P<0.01),the escape latency period was significantly shortened(P<0.05,P<0.01),and The Times of crossing the effective area were significantly increased(P<0.05,P<0.01).3.ELISA indicatorsCompared with the sham operation group,the levels of inflammatory cytokines IL-6,IL-1β,TNF-α in the brain homogenate of rats in the model group were significantly increased(P<0.01),and the levels of neurotransmitters Ach and DA were significantly decreased(P<0.01).Compared with the model group,the leels of inflammatory cytokines IL-6,IL-1β,TNF-α in the brain homogenate of rats in each dose group were significantly reduced(P<0.05,P<0.01),and the leels of neurotransmitters Ach and DA were significantly increased(P<0.05,P<0.01).4.Cerebral blood flowCompared with the sham operation group,the average perfusion volume of rats in the model group was significantly reduced within 10 s and all the time periods after calm(P<0.01).Compared with the model group,the average blood perfusion volume of rats in each drug group was significantly increased within10 s and all the time periods after tranquilization(P<0.05,P<0.01).5.Pathological changes in the hippocampal CA1 and cortical regionsThe neurons in the hippocampal CA1 and cortical regions of the rats in the sham operation group were arranged neatly and the structure was basically normal.In the model group,the neurons in the CA1 and cortical areas of the hippocampus were disordered,with incomplete morphology.The cytoplasm was rare,the nuclei were deeply stained and constricted in a triangular or irregular shape,and the mitochondria in the CA1 area were malformed and swollen,and some of the mitochondria were even broken and dissolved into transparent vacuoles.The pathological damage in the hippocampal CA1 and cortical areas was improved in each group.6.TUNEL detectionCompared with the sham operation group,the apoptosis rate in the hippocampal CA1 region was significantly increased in the model group(P<0.01).Compared with the model group,the apoptosis rate of the hippocampal CA1 region was significantly reduced in each group(P<0.01).7.The expression of PI3 K,Akt and caspase-3 was detected by immunohistochemistryCompared with the sham operation group,the expression of PI3 K and Akt in the CA1 region of the hippocampus was significantly decreased in the model group(P<0.01),while the expression of caspase-3 was significantly increased in the model group(P<0.01).Compared with the model group,the expression of PI3 K and Ak in the CA1 region was significantly increased(P<0.01),and the expression of caspase-3 was significantly decreased(P<0.05,P<0.01).Conclusion:1.The addition and reduction of modified Dihuang Yinzi could alleviate the pathological morphological changes in the hippocampal CA1 and cortical regions of the VD model rats prepared by 2-vo method,thus improving the cognitive impairment of the rats.2.Modified Dihuang Yinzi can reduce the level of IL-6,IL-1β,TNF-α in brain homogenate,improve Ach and DA levels and blood perfusion in brain homogenate,reduce inflammation,relieve cholinergic system disturbance,increase cerebral blood flow,and play a protective role in brain.3.Modified Dihuang Yinzi can increase the expression of PI3 K and Akt in the hippocampal CA1 region and decrease the expression of caspase-3,suggesting that modified Dihuang Yinzi may inhibit apoptosis by regulating the mitochondrial apoptosis pathway mediated by the PI3K/Akt pathway and play a neuroprotective role on VD rats.