Kong Xiangyi, Guan Jian, Gong Shun, Wang Renzhi
Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China;Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Harvard University, Massachusetts 02114, USA.
Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
Chin Med Sci J. 2017 Jun 10;32(2):92-9. doi: 10.24920/J1001-9294.2017.020.
Objective Oxidative stress (OS) plays a crucial role in ischemic stroke. Grape seed procyanidin extract (GSPE) was reported to be a critical regulator of OS. We hypothesized that GSPE might also be protective in ischemia-reperfusion brain injury. This study aimed to explore whether GSPE administration can protect mice from ischemia-reperfusion brain injury.Methods Transient middle cerebral artery occlusion (MCAO) was conducted followed by reperfusion for 24 hours to make ischemia-reperfusion brain injury in mice that received GSPE (MCAOG, n=60) or normal saline (MCAONS, n=60). Sham-operated mice (GSPE group and normal saline group) were set as controls. The neurological severity score (NSS) was used to evaluate neural function impairment 1 hour, 24 hour, 3 days and 7 days after MCAO. Mice underwent brain T2WI imaging with a 3T animal MRI scanner 24 hours after reperfusion, and the stroke volume of brains were calculated according to abnormal signal intensity. Immunohistopathological analysis of brain tissues at 24 h after reperfusion was performed for neuronal nuclear antigen (NeuN), CD34, Bcl-2, and Bax. Glutathione peroxidation (GSH-Px) activity and the level of malonaldehyde (MDA) of brain tissue were also examined. The above indexes were compared among the groups statistically.Results Significant functional improvement was observed 24 hours after MCAO in MCAOG group compared to MCAONS group (P<0.05). MCAOG group had smaller cerebral stroke volume (22.46 ± 11.45 mm vs. 47.84±9.06 mm, P<0.05) than MCAONS group 24 hours after MCAO. More mature NeuN-immunoreactive neurons and more CD34-positive cells in peri-infarct zones were observed in brain tissue of MCAOG mice 24 h after MCAO than that of MCAONS mice (both P<0.05). MCAONS mice had significantly higher number of Bax-positive cells in brain tissue than MCAOG (P<0.05). The mean MDA level was significantly lower (P<0.05) and the GSH-Px activity was significantly higher (P<0.05) in brains of MCAOG mice compared to those of MCAONS mice.Conclusion GSPE administration protects mice from ischemia-reperfusion brain injury through attenuating oxidative stress and apoptosis, promoting angiogenesis, and activating antioxidant enzyme GSH-Px. GSPE may represent a new therapeutical direction for the treatment of ischemia-reperfusion brain injury.
目的 氧化应激（OS）在缺血性卒中中起关键作用。据报道，葡萄籽原花青素提取物（GSPE）是OS的关键调节因子。我们推测GSPE可能对缺血再灌注脑损伤也具有保护作用。本研究旨在探讨给予GSPE是否能保护小鼠免受缺血再灌注脑损伤。
方法 对接受GSPE（MCAOG组，n = 60）或生理盐水（MCAONS组，n = 60）的小鼠进行短暂性大脑中动脉闭塞（MCAO），随后再灌注24小时以造成缺血再灌注脑损伤。将假手术小鼠（GSPE组和生理盐水组）设为对照。在MCAO后1小时、24小时、3天和7天，使用神经功能缺损评分（NSS）评估神经功能损伤情况。再灌注24小时后，用3T动物MRI扫描仪对小鼠进行脑T2WI成像，并根据异常信号强度计算脑梗死体积。在再灌注24小时后，对脑组织进行免疫组织病理学分析，检测神经元核抗原（NeuN）、CD34、Bcl-2和Bax。还检测了脑组织的谷胱甘肽过氧化物酶（GSH-Px）活性和丙二醛（MDA）水平。对各组上述指标进行统计学比较。
结果 与MCAONS组相比，MCAOG组在MCAO后24小时观察到显著的功能改善（P < 0.05）。MCAO后24小时，MCAOG组的脑梗死体积（22.46 ± 11.45 mm vs. 47.84 ± 9.06 mm，P < 0.05）小于MCAONS组。与MCAONS组小鼠相比，MCAO后24小时，MCAOG组小鼠脑组织梗死周边区观察到更多成熟的NeuN免疫反应阳性神经元和更多CD34阳性细胞（均P < 0.05）。MCAONS组小鼠脑组织中Bax阳性细胞数量显著多于MCAOG组（P < 0.05）。与MCAONS组小鼠相比，MCAOG组小鼠脑内平均MDA水平显著降低（P < 0.05），GSH-Px活性显著升高（P < 0.05）。
结论 给予GSPE可通过减轻氧化应激和细胞凋亡、促进血管生成以及激活抗氧化酶GSH-Px来保护小鼠免受缺血再灌注脑损伤。GSPE可能代表了治疗缺血再灌注脑损伤的一个新的治疗方向。
