Objective To investigate the protective effect of astragaloside Ⅳ on N-methyl-D-aspartic acid receptor(NMDAR)-mediated neuronal excitotoxicity injury.Methods Hippocampal neurons isolated from newborn C57/BL6J mice aged 0-1 d were used for primary cell culture.The cultured cells were randomly divided into control group,N-methyl-D-aspartic acid(NMDA)injury model group,oxygen-glucose deprivation(OGD)model group,NMDAR inhibitor ketamin intervention group,and astragaloside Ⅳ intervention group.Hoechst-33342 staining was used to observe the apoptosis of neurons in each group,and ELISA was used to detect the release of lactate dehydrogenase(LDH);Ca2 imaging was used to observe the intracellular calcium concentration of neurons under different conditions[addition of NMDA;pretreatment with NMDAR inhibitor APV(100 μmol/L)+NMDA;astragaloside Ⅳ(100 μmol/L)pretreatment+NMDA;extracellular fluid without Ca2++NMDA];Western blot was used to determine the expression of activated cysteinyl aspartate specific proteinase-3(cleaved caspase-3)in neurons of each group.Another group of C57BL/6 male mice aged 4-6 weeks was used to prepare coronal brain slices containing the hippocampus,and the changes in postsynaptic membrane currents were observed using a voltage clamp.Results Compared with the application of astragalosideⅣ(100 μmol/L),the average peak of miniature excitatory postsynaptic currents in hippocampal CA1 pyramidal cells decreased[(9.96±0.43)pA vs.(12.63±0.45)pA;t=3.741,P＜0.05],and the average frequency[(0.52±0.03)Hz vs.(0.68±0.05)Hz;t=2.933,P＜0.05]decreased.Compared with the NMDA injury model group,the astragaloside Ⅳ group had a lower rate of neuronal apoptosis,less LDH release,lower expression of cleaved caspase-3,and a decrease in intracellular calcium influx(all P＜0.05).In the in vitro ischemia model OGD,astragaloside Ⅳ showed a similar neuroprotective effect.Conclusions Astragaloside Ⅳhas a protective effect on NMDAR-mediated neuronal excitotoxicity injury,and the mechanism is related to inhibition of NMDAR.
维普
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