银杏叶提取物EGb761抑制脊髓损伤后的细胞凋亡

目的： 探讨银杏叶提取物EGb761对实验性大鼠脊髓损伤后神经保护的作用及其机制。方法： 成年雄性SD大鼠132 只，体重200~250g，随机分为正常对照组（N组）、损伤组（T组）、甲基强的松龙治疗组（MP组）和 EGb761 治疗组（EGb761组），每组 33 只。T组、MP组、EGb761组用改良 Allen法以25GCF损伤力度致伤大鼠，建立 T9 脊髓中度损伤模型。术后4h、8h、24h每组随机取3只动物切取损伤区1cm脊髓节段，分别用黄嘌呤氧化酶法和硫代巴比妥酸（TBA）法测定脊髓组织中超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量。分别于术后24h、 3d、 5d、 7d、 14d 处死动物(n=6)，快速取T9 节段脊髓，TUNEL法标记细胞凋亡，免疫组化方法检测诱生型一氧化氮合酶（iNOS）的表达。结果：术后4h、8h、24h EGb761治疗组SOD活性及MDA含量与损伤对照组比较均有显著差异（P<0.01）。术后各时相点EGb761治疗组神经细胞凋亡指数和iNOS表达阳性细胞率均低于损伤对照组（P<0.01或P<0.05）。结论：EGb761能抑制脊髓损伤后的脂质过氧化反应，减轻神经细胞的凋亡，其机制可能与抑制iNOS表达有关。

Extract of ginkgo biloba EGb761 inhibits cell apoptosis following spinal cord injury

The neuroprotective effects of ginkgo biloba extract have been shown in rats following spinal cord injury (SCI). However, the precise protective mechanisms remain unclear. In the present study, low-acid water-soluble extract of ginkgo biloba EGb761 was used to treat rats with SCI. Xanthin oxidase, thiobarbituric acid, terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling assay, and immunohistochemistry were utilized to detect lipid peroxidation, neural cell apoptosis, and inducible nitric oxide synthase activity in rats with SCI. Results revealed significantly increased superoxide dismutase activity, decreased malondialdehyde content, apoptotic index, and inducible nitric oxide synthase expression in SCI rats following EGb761 treatment. Therefore, EGb761 suppressed lipid peroxidation following SCI, relieved neural cell apoptosis, inhibited inducible nitric oxide synthase expression, and ultimately exerted protective effects on SCI.