三七皂苷Rg1上调SD大鼠大脑皮质巯醇抗氧化物(酶)发挥抗衰老作用

目的探讨三七皂苷Rg1抗衰老的分子机制。方法90只SD大鼠随机分为假手术组、模型组和治疗组。采用侧脑室注射β淀粉样蛋白1-42(Aβ1-42)联合腹腔注射D-半乳糖(D-gal)构建SD大鼠衰老模型,并同时给予三七皂苷Rg1预防性治疗,采用Morris水迷宫实验(MWM)进行行为学检测,用化学比色法检测大脑皮质谷胱甘肽还原酶(GR)和谷胱甘肽过氧化物酶(GSH-Px)的含量。用免疫组织化学法和免疫印迹法检测大脑皮质中Caspase-3前体蛋白和Bcl-2的含量。结果衰老模型组与假手术组比较:逃避潜伏期明显延长(P0.05),在第Ⅲ象限逗留的时间明显减少(P0.05),跨越平台次数明显减少(P0.05),皮质GR和GSH-Px的含量降低(P0.05),Caspase-3前体蛋白阳性神经元数明显减少(P0.05),Caspase-3前体蛋白活化切割增加(P0.05);而三七皂苷Rg1治疗后:大鼠逃避潜伏期明显缩短(P0.05),在第Ⅲ象限逗留的时间明显增加(P0.05),跨越平台次数明显增加(P0.05),皮质GR和GSH-Px的含量升高(P0.05),Caspase-3前体蛋白阳性神经元数明显增加(P0.05),Caspase-3前体蛋白活化切割减少(P0.05)。而Bcl-2阳性神经元数及表达在3组之间没有显著差异(P0.05)。结论三七皂苷Rg1能通过上调衰老模型大鼠皮质内源性巯基抗氧化物(酶)GR和GSH-Px的含量,抑制凋亡相关蛋白Caspase-3前体蛋白的活化切割而改善学习记忆能力,对抗大鼠神经系统衰老。

Notogisenoside Rg1 upregulates the thiol antioxidants and resists aging in rats

Objective In order to investigate anti-ageing mechanisms of the notoginsenoside Rg1,we used Aβ_(1-42) and D-galactose to establish aging rat model. Methods Ninety rats were divided into three groups at random: sham group, model group, treatment group. Aging rat models were established by injecting peritoneally D-galactose (100 mg/kg) to the rats for 56 days and after 35 days aggregated Aβ_(1-42)(μg) was injected to the right lateral ventricle of rats. Meantime, rats were treated by intragastric administration the notoginsenoside Rg1. Then spatial memory of experimental rats was examined with the Morris water maze(MWM). The thiol antioxidants including glutathione reductase (GR) and glutathione peroxidase (GSH-Px) activities were examined by colorimetric method. The concentration of the pro-caspase-3 and Bcl-2 were examined by the immunohistochemistry and Western blotting method. Results In aging model rats escape latercies were significantly prolonged (P<0.05), while decreases were seen in the time of staying the third quadrants of platform, the number of crossing over a platform, the concentration of the GR, GSH-Px, and pro-caspase-3 as compared with the sham group(P<0.05). After treatment of the notoginsenoside Rg1, the aging model rats exhibited significant increases in the time of staying the third quadrants of platform, the number of crossing over a platform, the concentration of the GR, GSH-Px, and pro-caspase-3(P<0.05), while a decrease was observed in escape latercies as compared to control group(P<0.05). Moreover there was no significant difference in the expression of the Bcl-2(P>0.05). Conclusion The results from our study indicate that the notoginsenoside Rg1 could improve the oriented learning and memory capacity and prevent the neurodegeneration of central nervous systems in aging model rats by up-regulating the expression of the thiol antioxidants(including GR and GSH-Px) and resisting the cleavage of the pro-caspase-3.