蓝布正提取物对血管性痴呆大鼠学习记忆能力及海马NT-3,BDNF蛋白表达的影响

目的:观察蓝布正提取物(GHE)对血管性痴呆(VD)大鼠学习记忆能力的影响并探讨其作用的机制。方法:采用双侧颈总动脉结扎法制作VD大鼠模型,将大鼠随机分成假手术组,模型组,GHE高、中、低剂量组(7,3.5,1.75 g·kg~(-1))和阳性药组(天保宁银杏叶片,0.007 g·kg~(-1)),各组灌胃相应药物,每日1次,连续35 d,在第30~35天进行Morris水迷宫实验检测大鼠的学习记忆能力,Morris水迷宫实验结束后处死大鼠,收集大脑样本,免疫组化法检测海马CA1区B细胞淋巴瘤-2(Bcl-2)相关X蛋白(Bax),Bcl-2,神经营养因子-3(NT-3),脑源性神经营养因子(BDNF)蛋白表达。结果:与模型组比较,GHE高、中剂量组可明显缩短大鼠的逃避潜伏期,增加穿越平台数(P0.05);GHE高、中、低剂量组可显著降低海马CA1区Bax表达,升高Bcl-2,NT-3,BDNF表达(P0.05,P0.01)。结论:GHE能改善VD大鼠的学习记忆能力,其机制可能与促进海马CA1区NT-3,BDNF的表达,抑制神经细胞凋亡有关。

Effect of Gei Herba Extract on Learning and Memory Ability and Expression of NT-3 and BDNF Protein in Hippocampus of Vascular Dementia Rats

Objective: To explore the protective effect and mechanism of Gei Herba extract (GHE) on memory and learning ability of rats model of vascular dementia (VD). Method: Rats with vascular dementia were prepared with bilateral carotid artery ligation. Then the rats were randomly divided into 6 groups, namely sham operation group, model group, GHE high, medium and low dose groups (7, 3.5,1.75 g·kg^-1), and Taponing positive control group (0.007 g·kg^-1). The corresponding drug was given by oral administration for 35 d, once a day. The behavior tests were carried out by water maze task on day 30-35 to test the memory and learning abilities of the rats, then they were sacrificed at the end of water maze test. The protein expression levels of B-cell lymphoma-2(Bcl-2) assolated X protein(Bax), Bcl-2, nerve neurotrophic factor-3(NT-3) and nerve neurotrophic factor-3(BDNF) in hippocampal CA₁ region of brain samples collected after the last administration were detected by immunocytochemistry. Result: GHE high and middle dose groups can significantly shorten the escape latency and increase the number of cross platforms (P<0.05); GHE high, middle and low dose groups can significantly decline the expression levels of Bax and rise the expression levels of Bcl-2, NT-3 and BDNF (P<0.05, P<0.01). Conclusion: GHE can improve learning and memory abilities of VD rats, and its mechanism may be related to the promotion of NT-3 and BDNF expression in hippocampal CA₁ region and the inhibition of neurons apoptosis.