Dengzhan Xixin(灯盏细辛)Capsules Protect Rats from Chronic Cerebral Ischemia-Induced Brain Injury and PC 12 Cells from Hypoxia Injury
Objective:To investigate the effects of Dengzhan Xixin(灯盏细辛)Capsules(DZXXC)on chronic cerebral ischemia in rats and co-balt chloride-induced hypoxia injury in PC 12 cells,and to explore the neuroprotective effect of DZXXC on chronic ischemic injury.Meth-ods:(1)Animal experiment:The rat model of chronic cerebral ischemia was prepared by permanent ligation of bilateral common carotid ar-teries.The model,sham operation,DZXXC(120 mg/kg),and nimodipine(16 mg/kg)groups were set up respectively.After 8 weeks of administration,the Morris water maze test was carried out to examine the cognitive function of rats,and the levels of malondialdehyde(MDA),superoxide dismutase(SOD),and glutathione peroxidase(GSH-px)in the serum were determined.Meanwhile,the cortical tissue was stained with hematoxylin-eosin and examined for the expression of protein kinase B(AKT),phosphorylated AKT(p-AKT),and cleaved caspase 3 by Western blotting.(2)Cell experiment:The half maximal inhibitory concentration(IC50)of DZXXC on PC 12 cells was meas-ured,and the PC 12 cell model of hypoxia injury was established with cobalt chloride.The proliferation of the model cells with and without drug treatment was evaluated by the methyl thiazolyl tetrazolium(MTT)method.The apoptosis of the cells was evaluated by the annexin V-FITC/PI double staining method.Results:(1)Animal experiment:Compared with the sham operation group,the model group showed in-creased latency and reduced number of crossing the platform in the Morris water maze test(P<0.01),elevated MDA level and lowered SOD and GSH-px levels in the serum,decreased p-AKT/AKT ratio(P<0.05),and up-regulated expression of cleaved Caspase 3(P<0.01).Moreover,the model group presented abnormal cell morphology,karyopyknosis of neurons,and obscure boundaries between cytoplasm and nucleus.Compared with the model group,DZXXC shortened the latency and the movement distance of finding platforms in the navigation test,and increased the number of crossing the platform in the spatial probe test(P<0.01).Furthermore,DZXXC lowered the MDA level and elevated the SOD and GSH-px levels in the serum(P<0.05 or 0.01),increased the p-AKT/AKT ratio,and down-regulated the expres-sion of cleaved Caspase-3(P<0.01).(2)Cell experiment:The apoptosis rate in the model group was higher than that in the normal control group(P<0.01).The IC50 value of DZXXC was 0.84 mg/mL.Compared with the model group,DZXXC promoted the cobalt chloride-in-duced proliferation and reduced the apoptosis of PC12 cells(P<0.05 or 0.01).Conclusion:DZXXC can counteract oxidative damage to improve cognitive function in the rat model of chronic cerebral ischemia,and it may activate the AKT/Caspase-3 signaling pathway to reduce ischemic neuronal apoptosis,thus exerting the cerebral neuroprotective effects.