川续断总皂苷对血管性痴呆大鼠的神经保护作用及对海马CA1区凋亡调控基因表达的影响

Total Saponins in Radix Dipsaci Has Effect on Protection of Nerves in Rats with Vascular Dementia and Expression of Regulatory Gene of Apoptosis in Hippocampal CA1 Area

目的:探讨川续断总皂苷对血管性痴呆(VD)大鼠的神经保护作用及对海马CA1区凋亡调控基因表达的影响。方法:采用永久性结扎双侧颈总动脉的方法建立大鼠VD模型。模型制备成功后第30天,川续断总皂苷低、高剂量组分别灌胃给予25 mg/kg、50 mg/kg的川续断总皂苷,尼麦角林组给予7 mg/kg的尼麦角林,假手术组和模型组给予等量生理盐水。连续给予4周后进行Morris水迷宫实验,对海马组织进行病理学检查,检测海马CA1区组织中丙二醛(MDA)、谷胱甘肽(GSH)、超氧化物歧化酶(SOD)、聚ADP-核糖聚合酶(PARP)、B淋巴细胞瘤-2 (Bcl-2)、Bcl-2相关X蛋白(Bax)、半胱氨酸蛋白酶3(Caspase-3)水平。结果:假手术组大鼠海马CA1区细胞多且排列紧密,层次清晰;模型组大鼠海马CA1区细胞数量减少,排列紊乱,少数神经细胞明显肿胀;川续断总皂苷低剂量组大鼠海马CA1区细胞数量较多,排列较密,少数神经细胞变性、萎缩;川续断总皂苷高剂量组和尼麦角林组大鼠海马CA1区组织形态学变化介于川续断总皂苷低剂量组和假手术组之间。与假手术组比较,模型组大鼠逃避潜伏期、海马CA1区组织中MDA、PARP、Bax、Caspase-3水平显著升高(P<0.05),穿越平台次数、海马CA1区组织中GSH、SOD、Bcl-2水平显著降低(P<0.05)。与模型组比较,川续断总皂苷低、高剂量组和尼麦角林组大鼠逃避潜伏期、海马CA1区组织中MDA、PARP、Bax、Caspase-3水平显著降低(P<0.05),穿越平台次数、海马CA1区组织中GSH、SOD、Bcl-2水平显著升高(P<0.05)。川续断总皂苷高剂量组和尼麦角林组各指标比较,差异无统计学意义(P>0.05)。结论:川续断总皂苷能改善VD大鼠的学习记忆能力,其机制可能与调控海马CA1区凋亡基因表达有关。

Objective:To discuss that total saponins in radix dipsaci has effect on protection of nerves in rats with vascular dementia(VD) and expression of regulatory gene of apoptosis in hippocampal CA1 area. Methods:The VD models of rats were established by permanent ligation of bilateral common carotid artery. On the 30 thday after successful establishment, the groups of total saponins in radix dipsaci of low and high dose were given gastric perfusion with 25 mg/kg and 50 mg/kg total saponins in radix dipsaci respectively;the nicardepine group was given 7 mg/kg nicardepine;the sham surgery group and the model group were given normal saline of same volume. After four-week continuous medication,Morris water maze test was conducted;hippocampus tissue was examined pathologically;in tissue of hippocampal CA1 area, the levels of malondialdehyde(MDA),glutathione(GSH),superoxide dismutase(SOD),poly-ADP-ribosomal polymerase(PARP),B-cell lymphoma-2(Bcl-2), Bcl-2 associated X protein(Bax) and Cysteine protease-3(Caspase-3) were detected. Results: In hippocampal CA1 area, there were cells in large number with close arrangement and distinct layout in the sham surgery group;in the model group,the number of cells was decreased,cells were arranged disorderly,and a few nerve cells were evidently swollen;there were cells in larger number with closer arrangement in the group of total saponins in radix dipsaci of low dose,and a few nerve cells were degenerated and shrunk. The morphological changes in tissue of hippocampal CA1 area in the group of total saponins in radix dipsaci of high dose and the nicardepine group were between those in the group of total saponins in radix dipsaci of low dose and the sham surgery group. Compared with those in the sham surgery group,in the model group, the escape latencies were lengthened, and the levels of MDA, PARP, Bax and Caspase-3 in tissue of hippocampal CA1 area were significantly increased(P<0.05);the times of crossing the platform and the levels of GSH,SOD and Bcl-2 in tissue of hippocampal CA1 area were significantly decreased(P<0.05). Compared with those in the model group,in the groups of total saponins in radix dipsaci of low and high dose and the nicardepine group,the escape latencies were shortened,and the levels of MDA,PARP,Bax and Caspase-3 in tissue of hippocampal CA1 area were significantly decreased(P<0.05),and the times of crossing the platform and the levels of GSH,SOD and Bcl-2 in tissue of hippocampal CA1 area were significantly increased(P<0.05). When compared each index between the group of total saponins in radix dipsaci of high dose and the nicardepine group, there was no significance in the difference(P>0.05). Conclusion: Total saponins in radix dipsaci can improve ability of learning and memory of VD rats, whose mechanism may be related to its regulation and control of gene expression of apoptosis in hippocampal CA1 area.