银杏叶提取物对辐射损伤小鼠脾脏氧化应激和蛋白激酶C活性的影响

目的：探讨银杏叶提取物（GBE）对辐射小鼠脾脏细胞氧化损伤相关蛋白表达的影响，阐明其作用机制。方法：将60只ICR小鼠随机分为空白对照（NC）组、辐射对照（IC）组（4.0 Gyγ线照射）、低剂量GBE （IC+GBEL）组（4.0 Gyγ线+5.0mg·kg^-1 GBE）、中剂量GBE （IC+GBEM）组（4.0 Gyγ线+10.0mg·kg^-1GBE）和高剂量GBE （IC+GBEH）组（4.0 Gyγ线+20.0mg·kg^-1GBE），每组12只。各剂量GBE组小鼠连续给予相应剂量GBE共14 d，第15天除NC组小鼠外均给予总剂量为4.0 Gy的γ射线全身照射。于照射后24 h采用生化方法检测各组小鼠脾组织中丙二醛（MDA）水平，超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽过氧化物酶（GSH-px）活性；免疫组织化学法观察各组小鼠脾脏细胞中8-羟基脱氧鸟嘌呤（8-OHdG）表达水平，ELISA法检测各组小鼠脾组织中蛋白激酶C （PKC）活性。结果：与NC组比较，IC组和各剂量GBE组小鼠脾组织中MDA水平和8-OHdG表达水平明显升高（P<0.05），SOD、CAT、GSH-px和PKC活性明显降低（P<0.05）；与IC组比较，各剂量GBE组小鼠脾组织中MDA水平和8-OHdG表达水平明显降低（P<0.05），SOD、CAT、GSH-px和PKC活性明显升高（P<0.05）。结论：GBE可以抑制辐射损伤小鼠脾脏内的氧化应激，调节恢复脾脏PKC活性，从而发挥其对辐射损伤的保护作用。

Effect of Ginkgo biloba L. extract on oxidative stress and activity of protein kinase C in spleen tissue of mice with irradiation damage

Objective: To investigate the influence of Ginkgo biloba L. extract(GBE) in the expressions of oxidative damage-related proteins in the spleen tissue of the mice with radiation damage, and to clarify its mechanism.Methods: Sixty ICR mice were randomly divided into normal control (NC) group, irradiation control (IC) group(4.0 Gyγ-ray radiation), low dose of GBE (IC+GBEL) group(4.0 Gyγ-ray+5.0mg·kg^-1 GBE), medium dose of GBE (IC+GBEM) group(4.0 Gyγ-ray+10.0mg·kg^-1 GBE) and high dose of GBE (IC+GBEH) group(4.0 Gyγ-ray+20.0mg·kg^-1 GBE)(n=12). After continuous administration of GBE for 14 d, all mice received the whole body radiation of γ-ray with the total dose of 4.0 Gy on the 15th day except for the mice in NC group. The levels of malonaldehyde (MDA), the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-px) in the spleen tissue of the mice in various groups were measured by biochemical method 24 h after radiation. The expression levels of 8-hydroxy-2 deoxyguanosine (8-OHdG) in the spleen tissue of the mice in various groups were examined by immunohistochemistry. The activities of protein kinase C(PKC) in the spleen tissue of the mice in various groups were detected by ELISA.Results: Compared with NC group, the levels of MDA and 8-OHdG in the spleen tissue of the mice in IC and different doses of GBE groups were significantly increased(P<0.05), and the activities of SOD, CAT, GSH-px and PKC were significantly decreased(P<0.05). Compared with IC group, the levels of MDA and 8-OHdG in the spleen tissue of the mice in different doses of GBE groups were significantly decreased(P<0.05), and the activities of SOD, CAT, GSH-px and PKC were significantly increased(P<0.05).Conclusion: GBE can inhibit the oxidative stress and regulate the PKC activity in the spleen tissue of the mice with irradiation damage to play a protective role against the radiation damage.