银杏内酯对体外PC12细胞拟缺血缺氧损伤及缺血继发性凋亡的作用

目的：研究银杏内酯对缺血缺氧损伤情况下体外培养PC12细胞的保护作用及其对该细胞凋亡的影响，并探讨其作用机制。方法：在离体培养的PC12细胞，用NaCN无糖培养造成拟缺血损伤模型，用H2O2模拟氧自由基损伤，分别通过形态学观察、MTT微量比色等方法研究药物对上述模型的保护作用。另将PC12细胞在无血清条件下培养96h，通过琼脂糖凝胶电泳检测其凋亡情况，并用流式细胞术检测细胞的凋亡程度及凋亡相关基因bcl-2在其中的作用。结果：银杏内酯终浓度10^-5、10^-6、10^-7mol/L能抑制NaCN无糖和H2O2培养造成的细胞损伤，明显增强细胞活力。凝胶电泳可见到明显的梯型条带，流式细胞术检测凋亡情况发现模型组凋亡率为10．40％，银杏内酯10^-5mol/L组的凋亡率为3．96％。同时发现药物组和模型组细胞中的bcl-2基因表达没有显著差异。结论：银杏内酯具有神经保护作用，且该作用与药物的抗凋亡能力有关，但这种抗凋亡作用似乎并不是通过bcl-2基因的调控实现的。

Effects of Ginkgolides on Imitational Anemic Anoxic Injuries and Secondary Apoptosis of PC12 cells in vitro

AIM: To study the effects of Ginkgolides on PC12 cells injured by anoxia or reactive oxygen species (ROS) in vitro as well as its effects and mechanism in cell apoptosis. METHOD: The PC12 cells, which had been cultured with various concentrations of Ginkgolides, were treated with NaCN or H2O2 to imitate the anemia model or ROS injury respectively. The proliferation of cells was determined by morphological observations and tetrazolium assay (MTT). Furthermore, the PC12 cells were cultured deprived of serum for 96 h to form apoptosis. The effects of Ginkgolides on the cell apoptosis were estimated by agarose gel electrophoresis and flow cytometer. Bcl-2 gene expression in the apoptosis cells was also measured by flow cytometer. RESULT: Ginkgolides (10-5～10-7 mol/L) could markedly inhibit the injures of NaCN or H2O2 on the PC12 cells and increase the cell activity compared with the model groups (P<0.01). There were notable DNA bladders on the electrophoresed gel. The apoptosis percentage of the model cells and drug treated cells were 10.40% and 3.96% respectively (P<0.01) and there were no significant differences in the bcl-2 levels in both groups examined by flow cytometer. CONCLUSION: Ginkgolides are able to protect the injured PC12 cells against cell apoptosis. However, this effect seems to have no relation with bcl-2 gene expression.