Neuroprotective Effects And Its Mechanism Of Oxysophoridine On Rat Hippocampal Neurons Injured By Oxygen-glucose Deprivation And Reperfusion

Objectives In this study we investigated the protective effects of Oxysoph-oridine on hippocampal neurons injured by oxygen-glucose deprivation/reperfusi-on (OGD/Rep) in vitro and elucidated the related mechanisms.Methods1. Rat primary cultured cerebral hippocampal neurons exposed toOGD/Rep were used as an in vitro model of ischemia and reperfusion.2. The survival rate of nerve cells was measured by MTT assay. The nerve cell l-actate dehydrogenase(LDH) leakage rate was measured by chemical colorimetry. Thelevel of mitochondrial membrane potential (MMP) was detected using confocalmicroscopy.3. The culture medium glutamate content were measured by chemical colorimet-ry. Western blotting assay and real time quantitative PCR assay were used to evaluatethe expressions of NMDARNR1protein and mRNA. Intracellular calcium ionconcentration ([Ca2+]i) was detected using confocal microscopy. Malondialdehyde(MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase(GSH-Px), Nitric oxide synthase (NOS) and Nitric oxide (NO) were measured bychemical colorimetry.Results1. Compared with normal group, oxygen and glucosedeprivation-reperfusion injury model group can significantly reduce the survival rateof nerve cells (P＜0.01), increase the lactate dehydrogenase leakage rate (P＜0.01),decrease the fluorescence ratio of mitochondrial membrane potential (P＜0.01). 2. Compared with the OGD/Rep group, treatment with OSR (20,5,1.25mg/L)significantly increased cell viability (P＜0.01) and inhibited LDH release (P＜0.05,0.01). Compared with the OGD/Rep group, treatment with OSR (20,5mg/L) cansignificantly increase the fluorescence ratio of the mitochondrial membrane potential(P＜0.05,0.01).3. Compared with the OGD/Rep group, treatment with OSR (20,5,1.25mg/L)significantly inhibited Glutamate elevation (P＜0.05,0.01). Compared with theOGD/Rep group, treatment with OSR (20mg/L) decreased the expressions ofNMDANR1protein and mRNA (P＜0.05,0.01).4. Compared with the OGD/Rep group, treatment with OSR (20,5,1.25mg/L)significantly inhibited [Ca2+]ielevation (P＜0.05,0.01).5. Compare to the OGD/Rep group, treatment with OSR (20,5,1.25mg/L)significantly decreased the content of MDA and increased the activity of SOD (P＜0.05,0.01). Compare to the OGD/Rep group, treatment with OSR (20,5mg/L)significantly increased the activity of GSH-Px and CAT (P＜0.05,0.01). Compare tothe OGD/Rep group, treatment with OSR (20,5mg/L) significantly decreased thecontent of NO (P＜0.05,0.01). Compare to the OGD/Rep group, treatment with OSR(20,5,1.25mg/L) significantly decreased the activity of NOS (P＜0.05,0.01).Conclusion1. OSR have significantly protective effects on OGD/Rep-inducedneuronal damages in rat primary neuron cultures.2. The mechanism of OSR rely on anti-excitotoxicity. OSR also block theexcitotoxicity-induced increases in intracellular Ca2+elevation and ROS generation.