人参皂甙Rg1对大鼠局灶性脑缺血脑组织神经干细胞增殖的影响

目的 观察人参皂甙Rg1对大鼠局灶性脑缺血脑组织神经干细胞增殖的影响,探讨其在脑保护及抗衰老作用中的可能机制.方法 取成年雄性Wistar大鼠,用线栓法制作大鼠大脑中动脉闭塞(MCAO)模型,采用脉冲标记法,经腹腔注射5′-溴脱氧尿苷(BrdU)标记处于增殖状态的神经干细胞,用免疫组织化学单标及双标免疫荧光技术观察人参皂甙Rg1对局灶性脑缺血后BrdU和巢蛋白(nestin)的免疫活性及nestin/BrdU双标阳性细胞的影响,镜下观察脑内神经干细胞的分布,并计数行定量分析.结果 局灶性脑缺血后大鼠室管膜下区及海马齿状回有nestin、BrdU及nestin/BrdU双标免疫阳性细胞分布.应用人参皂甙Rg1后,上述各部位阳性细胞数明显增多,与缺血组之间有显著性差异(P＜0.01).结论 人参皂甙Rg1具有促使神经干细胞增殖的能力,这可能是其神经保护及抗衰老作用的机制之一.

Effects of ginsenoside Rg1 on the proliferation of neural stem cells in rats with focal cerebral ischemia

Objective To investigate the influence of ginsenoside Rgl on the proliferation of neural stem cells in adult rats with fo- cal cerebral ischemia,and to explore the possible mechanism of ginsenoside Rg1 in brain protection and anti-aging action.Methods The animal model of left middle cerebral artery occlusion(MCAO)was reproduced in adult male Wistar rats.The thymidine analog bromode- oxyuridine(BrdU)was administered intraperitoneally(50mg/kg,Sigma,USA)every four hours for four times before executing the ani- mals to label the proliferating cells.By the employment of immunohistochemical single staining and double-immunofluorescence technique, the number of BrdU immunoreacted nuclei in the subventricular zone(SVZ),the number of nestin positive cells in the subgranular zone (SGZ)as well as the nestin/BrdU double-labeled positive cells were counted.The effect of ginsenoside Rg1 on the immunoreactivity for BrdU,nestin and nestin/BrdU at 1d,3d,7d and 14d after focal cerebral ischemia were also observed to compare with that of controls,Re- sults The immunoreacted cells of BrdU,nestin and nestin/BrdU were seen in SVZ and SGZ in the hippocampus following focal cerebral ischemia.The number of BrdU,nestin-positive cells and the double-labeled positive cells all reached the peak on 7d and decreased on 14d after MCAO,and the expressions markedly increased after the rats were given ginsenoside Rg1,compared with the control(P<0.01). Conclusion The results indicated that ginsenoside Rg1 can promote the proliferation of neural stem cells in the SVZ and SGZ of hippocam- pus,and that this effect may be one of the mechanisms underlying the brain protection and anti-aging effects of ginsenoside Rg1.