中文摘要：

目的：探讨银杏叶提取物（ginkgo biloba extract，GBE）对缺糖缺氧一复糖复氧损伤新生大鼠皮层神经干细胞（neural stem cells，NSCs）的保护作用及其机制。方法：采用无血清法培养新生大鼠皮层NSCs，对NSCs进行缺糖．缺氧结合复糖．复氧处理。实验分为对照组、缺糖一缺氧结合复糖-复氧组和GBE组，MTT法检测细胞活性，DAPI染色检测原代培养细胞的凋亡，比色法测定乳酸脱氢酶（LDH）漏出率，流式细胞仪检测传代细胞的凋亡率，免疫荧光染色观察细胞的增殖分化的能力。结果：与缺糖缺氧一复糖复氧组相比，GBE明显提高了细胞的活性、存活率（P〈0．05），同时降低了LDH漏出率和凋亡率（P〈0．01）。DAPI染色显示：GBE可明显逆转缺糖缺氧导致的细胞凋亡。免疫荧光双标显示：与对照组相比，缺糖缺氧-复糖复氧组明显抑制了细胞Nestin／BrdU和Nestin／Tuj．1的表达；而与缺糖缺氧一复糖复氧组相比，GBE可显著促进细胞Nestin／BrdU和Nestin／Tuj-1的表达。结论：GBE能够增强皮层NSCs活性，减少细胞凋亡，促进细胞增殖、分化。提示GBE能够通过有效调节NSCs凋亡相关基因和促进细胞增殖与分化，进而对缺糖缺氧一复糖复氧损伤皮层NSCs起到保护作用。

英文摘要：

Objective： To explore protection role and the mechanism of extract of Ginkgo biloba on primary cultured cor- tical neural stem cells （NSCs） in neonatal rat during oxygen/glucose deprivation and reintroduction. Methods： Cortical NSCs were cultured in serum-free media, and then treated by oxygen/glucose deprivation and reintroduction. The experi- ments were randomly divided into the control group, the model group and the extract of Ginkgo biloba group. The cells vi- ability was determined by MTT assay. DAPI staining was used to detect cell apoptosis of primary NSCs. The leakage rate of lactate dehydrogenase （LDH） was measured by chromatometry. The apoptosis rate was quantitatively analyzed by flow cytometry. The ability of proliferation and differentiation was detected by immunofluorescence labeling. Results： Com- pared with the oxygen/glucose deprivation and reintroduction group, the cortical NSCs viability and the survival rate in the extract of Ginkgo biloba group were significantly increased（ P 〈 0.05 ）. In addition, in the extract of Ginkgo biloba group, the leakage rate of LDH and the apoptosis rate were significantly lower than those in the oxygen/glucose deprivation and reintroduction group（P 〈0.01 ）. DAPI staining showed that GBE restrained cell apoptosis indnced by oxygen/glucose deprivation and reintroduction. The double immunofluorescent labeling showed that compared with the control group, oxy- gen/glucose deprivation and reintroduction obviously inhibited the expression of Nestin/BrdU and Nestin/Tuj-1 of NSCs. However, GBE significantly increased the expression of Nesfin/BrdU and Nestin/Tuj-1 of NSCs compared with the oxy- gen/glucose deprivation and reintroduction group. Conclusion：The extract of Ginkgo biloba can enhance NSCs viability and reduce cell apoptosis and promote the proliferation and differentiation of NSCs, which may be one of the mechanisms for EGB on the neuron orotection during the oxygen/glucose deprivation and reintroduction.