目的 观察栀子苷对脑缺血再灌注损伤（CIRI）模型大鼠的神经保护作用及对胰高血糖素样肽-1受体（GLP-1R）/蛋白激酶B（Akt）信号通路的影响。方法 50只SD大鼠随机分为假手术组，模型组，栀子苷低、高剂量组及尼莫地平片组，每组10只。采用线栓法制备CIRI大鼠模型，缺血2 h再灌注24 h后，栀子苷低、高剂量组大鼠分别ig给予10、40 mg·kg^-1的栀子苷，尼莫地平片组大鼠ig给予8.1 mg·kg^-1尼莫地平，假手术组和模型组大鼠ig等体积生理盐水，每天1次，连续7 d。造模后及给药结束后，分别对各组大鼠进行神经功能缺损评分；给药结束后，采用酶联免疫吸附法（ELISA）检测血清中肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）及白细胞介素-6（IL-6）水平，苏木素-伊红（HE）染色检测脑组织病理学变化，尼氏染色检测神经元与尼氏小体变化，免疫组化染色检测脑组织B淋巴细胞瘤-2（Bcl-2）和Bcl-2关联X蛋白（Bax）表达，蛋白质印迹法（Western blotting）检测脑组织细胞色素C（Cyt-C）、半胱氨酸蛋白酶-3（Caspase-3）、半胱氨酸蛋白酶-9（Caspase-9）、胰高血糖素样肽-1受体（GLP-1R）及磷酸化蛋白激酶B（p-Akt）蛋白表达水平。结果 与假手术组比较，模型组大鼠神经功能缺损评分显著升高（P＜0.05），血清中TNF-α、IL-1β、IL-6水平显著升高（P＜0.05）；皮质细胞间质疏松、增宽，有大量神经元细胞质萎缩和细胞核损伤；脑神经元皱缩，尼氏小体变小，数目明显减少。大鼠脑组织Bcl-2表达显著降低（P＜0.05），Bax表达显著升高（P＜0.05）；脑组织中Cyt-C、Caspase-3、Caspase-9蛋白表达水平显著升高（P＜0.05），GLP-1R和p-Akt蛋白表达水平显著降低（P＜0.05）。与模型组比较，栀子苷高剂量组和尼莫地平片组大鼠神经功能缺损评分均显著降低（P＜0.05），血清中TNF-α、IL-1β、IL-6水平显著降低（P＜0.05），皮质细胞较为整齐，神经元细胞和尼氏小体损伤减小，Bcl-2表达显著升高（P＜0.05），Bax表达显著降低（P＜0.05），同时，Cyt-C、Caspase-3及Caspase-9蛋白表达水平显著下降（P＜0.05），GLP-1R和p-Akt蛋白表达水平显著升高（P＜0.05）。结论 栀子苷能够改善大鼠CIRI，减少神经元凋亡，其作用机制可能与激活GLP-1R/Akt信号通路有关。

Objective To investigate effect of geniposide on cerebral ischemia-reperfusion injury (CIRI) and its effects on glucagon like peptide-1 receptor (GLP-1R)/protein kinase B (Akt) signaling pathway. Methods Fifty SD rats were randomly divided into sham operation group, model group, low-dose geniposide group, high-dose geniposide group, and nimodipine tablet group, with 10 rats in each group. The thread embolism method was used to establish the CIRI model. After 2 h of ischemia and 24 h of reperfusion, the rats in low-dose and high-dose geniposide groups were given 10 mg·kg^-1 and 40 mg·kg^-1 geniposide by ig, respectively, rats in the nimodipine tablet group were given 8.1 mg·kg-1 nimodipine ig, rats in the sham operation group and model group were given an equal volume of normal saline, once a day for seven consecutive days. After modeling and administration, the neurological deficits of rats in each group were scored. Enzyme linked immunosorbent assay (ELISA) was used to detect the content of tumor necrosis factor- α (TNF- α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in serum. Hematoxylin-eosin (HE) staining was used to detect brain histopathological changes. Nissl staining was used to detect changes in neurons and Nissl bodies. Immunohistochemical staining was used to detect the expression of B lymphocyte tumor-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in brain tissue. Western blotting was used to detect cytochrome C (Cyt-C), Caspase-3, and Caspase-9, glucagon-like peptide-1 receptor (GLP-1R) and phosphorylated protein kinase B (p-Akt) protein expression levels. Results Compared with the sham operation group, the neurological deficit score of the model group was significantly higher (P < 0.05), the level of TNF-α, IL-1β, and IL-6 increased significantly (P < 0.05), cortical intercellular matrix was loose and widened, and there were a large number of neuronal cytoplasmic atrophy and nuclear damage, the brain neurons shrink, the Nissl body became smaller, and the number decreased significantly, the expression of Bcl-2 was significantly decreased (P < 0.05) and the expression of Bax was significantly increased (P < 0.05), the expression levels of Cyt-C, Caspase-3 and Caspase-9 protein in brain tissue were significantly increased (P < 0.05), and the expression levels of GLP-1R and p-Akt protein were significantly decreased (P < 0.05). After treatment, compared with model group, the neurobehavioral injury score of the high-dose geniposide group and nimodipine group was significantly reduced (P < 0.05), and the serum levels of TNF-α, IL-1β, and IL-6 were significantly reduced (P < 0.05), the cortical cells are relatively neat, the damage of neuronal cells and Nissl bodies were reduced, Bcl-2 expression was significantly increased, Bax expression was significantly reduced (P < 0.05). At the same time, the expression levels of Cyt-C, Caspase-3 and Caspase-9 protein decreased significantly, the expression levels of GLP-1R and p-Akt protein increased significantly (P < 0.05). Conclusion Geniposide can improve cerebral ischemia-reperfusion injury and reduce neuronal apoptosis in rats, and its mechanism may be related to the activation of GLP-1R/Akt signaling pathway.

R285.5

2021年广东省医学科研基金（B2022009）