银杏叶提取物促进脑缺血半暗带神经元自噬提高神经保护作用

银杏叶提取物(ginkgo biloba extract-761,EGb-761)注射液在中国常作为辅助药物被用于治疗脑卒中,但是,其潜在的细胞和药理机制尚未完全了解。该研究旨在探讨EGb-761是否通过调节缺血性脑卒中半暗带神经元的自噬从而发挥保护作用。采用雄性SD大鼠大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)再灌注模型,将MCAO大鼠随机分为5组,分别为Sham组、MCAO+saline组、MCAO+EGb组、MCAO+EGb+3-MA组和MCAO+3-MA组。脑缺血大鼠用EGb-761药物腹腔注射7天后,并使用自噬抑制剂3-MA侧脑室注射进行干预,分别通过蛋白免疫印迹法(WB)、实时荧光定量PCR(quantitative real-time PCR,qRT-PCR)和免疫荧光检测缺血半暗带的脑组织,以检测自噬的表达。另外,根据脑梗死体积、神经功能缺损和TUNEL检测神经元凋亡水平,以评估治疗效果。结果表明,与MCAO+saline相比,MCAO+EGb组的EGb-761显著提高了神经元自噬水平,同时,明显减轻了神经功能缺损、脑梗死面积和神经元凋亡。此外,相对于MCAO+EGb组,MCAO+EGb+3-MA组中的3-MA抵消了EGb增强神经元自噬的功效,并且仅使用3-MA继续加重了神经损伤。因此,EGB-761通过特异性促进脑缺血半暗带神经元自噬发挥神经保护作用。

Ginkgo Biloba Extract Promotes Neuronal Autophagy and Improves Neuroprotection in Penumbra of Cerebral Ischemia

EGb-761(ginkgo biloba extract-761)injection has been widely used as an adjuvantive therapy for cerebral stroke in China,but its underlying cellular and pharmacological mechanisms have not been fully understood.This study aims to investigate whether EGb-761 has a therapeutic effect by regulating the autophagy of neurons in the penumbra of ischemic stroke.Using the MCAO(middle cerebral artery occlusion)reperfusion model of male SD rats,the MCAO rats were randomly divided into 5 groups,namely Sham group,MCAO+saline group,MCAO+EGb group,MCAO+EGb+3-MA group and MCAO+3-MA group.Cerebral ischemic rats were injected intraperitoneally with EGb-761 for 7 days,and were injected with autophagy inhibitor 3-MA into the lateral ventricle.The brain tissue of the ischemic penumbra was used to detect the expression of autophagy by WB,qRT-PCR(quantitative real-time PCR)and immunofluorescence.In addition,the evaluation of therapeutic efficacy was based on cerebral infarction volume,neurological deficit,and TUNEL detection of neuronal apoptosis levels.The results showed that compared with MCAO+saline,the EGb-761 drug in the MCAO+EGb group significantly increased the expression of neuronal autophagy.At the same time,EGb-761 treatment significantly reduced the neurological deficit,cerebral infarction area and neuronal apoptosis.In addition,3-MA in the MCAO+EGb+3-MA group counteracted the effect of EGb to enhance neuronal autophagy,and only the use of 3-MA continued to aggravate the nerve damage,compared with the MCAO+EGb group.Therefore,EGB-761 exerts a neuroprotective effect by specifically promoting neuronal autophagy in the penumbra of cerebral ischemia.