| Objective: To explore the protective effect of Cerebroprotein Hydrolysate-I(CH-I)on hippocampal neurons in a mouse model of vascular dementia(VaD).Methods: Seventy SPF KM male mice were tested through the Y maze.The mice with poor learning ability were eliminated(10/70),and ten of remaining mice were randomly selected as the sham operation group(Sham).The remaining fifty mice were established VaD mouse model by bilateral common carotid artery occlusion surgery combined with caudal bloodletting,and only bilateral common carotid arteries were isolated in the sham group.After 7 days of modeling,Y maze was used to test the learning and memory ability of mice in each group.After behavioral detection,all VaD mice were randomly divided into model group(VaD),CH-I(10,20,30 mg/kg)group,and Cerebrolysin(CBL)10mg/kg group,with ten mice in each group.CH-I or CBL was given daily over ip for 28 days,and 0.9% normal saline was injected synchronously in the sham group and VaD group.After the last administration,Y maze was used to detect the learning and memory ability of mice in each group.Cell morphology of CA1 and CA3 in the hippocampal tissues of mice was observed by HE staining.Cell apoptosis in the hippocampal tissues was detected by TUNEL.The protein expression of PI3 K,p-PI3 K,Akt,p-Akt,caspase-9,caspase-3 and Bcl-2 in hippocampal tissues were analyzed by Western blot.Results: Behavioral tests showed that there were no significant differences in the pre-test training times and the success rate before modeling(P>0.05).After modeling,compared with sham group,the number of attempts in each model group increased(P<0.01),the test success rate decreased(P<0.05).After 28 days of administration,compared with VaD group,the number of pre-test training times of mice in each treatment group decreased(P<0.05),and the success rate of CH-I 10 and 20 mg/kg groups increased(P<0.01).HE staining results showed that,compared with sham group,the number of degenerations of nerve cells in hippocampal CA1 and CA3 region of VaD group was increased(P<0.01).After administration,compared with the VaD group,the number of degenerations of nerve cells in two regions of the hippocampus in each treatment group decreased(P<0.01),and the effect of CH-I 10mg/kg and CH-I 20 mg/kg groups were better than CH-I 30 mg/kg group(P<0.05).TUNEL staining showed that the number of apoptotic cells in hippocampal CA1 and CA3 regions was increased in VaD group compared with sham group(P<0.01).After administration,compared with VaD group,the number of apoptotic cells in the hippocampus of each administration group decreased(P<0.01).Western blot results showed that compared with sham group,p-Akt/Akt and Bcl-2 protein expressions decreased in VaD group(P<0.05),the expression of caspinase-9 and caspinase-3increased(P<0.05).After administration,p-Akt/Akt and p-PI3K/PI3 K expressions increased in the treatment groups compared with the VaD group(P<0.01),the expression of Bcl-2 protein in CH-I 20 mg/kg group increased(P<0.01).The expression of caspinase-9 and caspinase-3 decreased in CH-I groups(P<0.05),but CBL 10 mg/kg group had no significant change(P>0.05).Conclusions: Cerebroprotein hydrolysate-Ⅰ can improve the cognition and protect the hippocampal neurons of VaD mice,and the mechanism may be related to the activation of PI3K/Akt signaling pathway to inhibit cell apoptosis. |
