Li Xiaogang, Zhang Zhe, Wang Rui, Xia Xinxin, Liu Yonghui, Sun Lianqing
Department of Anesthesiology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China.
Department of Traditional Chinese Medicine, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China.
J Tradit Chin Med. 2017 Dec;37(6):746-755.
To investigate the effects of ginsenoside Rb1 on high glucose-induced neurotoxicity and the underlying molecular mechanism in primary cultured Schwann cells (SCs).
Cultured SCs were divided into six groups that received (a) normal glucose, (b) osmotic control, (c) high glucose, (d) high glucose plus 1 μM ginsenoside Rb1, (e) high glucose plus 10 μM ginsenoside Rb1, or (f) high glucose plus 100 μM alpha lipoic acid (ALA). Intracellular reactive oxygen species (ROS) generation and mitochondrial transmembrane potential (ΔΨm) were detected by flow cytometric analyses. Apoptosis was confirmed by the annexin V-FITC/propidium iodide (PI) method, and the concentration of 8-hydroxy-2-deoxy guanosine (8-OHdG) was detected by an enzyme-linked immunosorbent assay. Western blotting was performed to analyze the expression levels of important transcription factors such as cytochrome c, bcl-2, bax, activated caspase-3, and activated poly (ADP-ribose) polymerase (PARP).
Ginsenoside Rb1 inhibited high glucose-induced oxidative stress by decreasing ROS and 8-OHdG levels as well as mitochondrial depolarization in SCs. 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide and annexin V-FITC/PI assays showed that incubating SCs with high glucose decreased cell viability and increased the number of apoptotic cells, whereas treatment with ginsenoside Rb1 protected SCs against high glucose-induced cell damage. Furthermore, ginsenoside Rb1 down-regulated the expression of high glucose-induced bax and cytochrome c release but up-regulated bcl-2 expression. In addition, ginsenoside Rb1 attenuated high glucose-induced activation of caspase-3 and minimized cleavage of PARP in SCs.
These results suggest that ginsenoside Rb1 antagonizes high glucose-induced oxidative stress and activation of the mitochondrial apoptosis pathway in SCs.
研究人参皂苷Rb1对原代培养的雪旺细胞（SCs）中高糖诱导的神经毒性的影响及其潜在分子机制。
将培养的SCs分为六组，分别给予（a）正常葡萄糖、（b）渗透压对照、（c）高糖、（d）高糖加1 μM人参皂苷Rb1、（e）高糖加10 μM人参皂苷Rb1或（f）高糖加100 μM α-硫辛酸（ALA）。通过流式细胞术分析检测细胞内活性氧（ROS）生成和线粒体跨膜电位（ΔΨm）。采用膜联蛋白V-异硫氰酸荧光素/碘化丙啶（PI）法确认细胞凋亡，并通过酶联免疫吸附测定法检测8-羟基-2-脱氧鸟苷（8-OHdG）的浓度。进行蛋白质免疫印迹分析以检测重要转录因子如细胞色素c、bcl-2、bax、活化的半胱天冬酶-3和活化的聚（ADP-核糖）聚合酶（PARP）的表达水平。
人参皂苷Rb1通过降低SCs中的ROS和8-OHdG水平以及线粒体去极化来抑制高糖诱导的氧化应激。噻唑蓝和膜联蛋白V-异硫氰酸荧光素/PI测定表明，高糖孵育SCs会降低细胞活力并增加凋亡细胞数量，而人参皂苷Rb1处理可保护SCs免受高糖诱导的细胞损伤。此外，人参皂苷Rb1下调高糖诱导的bax表达和细胞色素c释放，但上调bcl-2表达。此外，人参皂苷Rb1减弱高糖诱导的SCs中半胱天冬酶-3的活化，并使PARP的裂解最小化。
这些结果表明人参皂苷Rb1可拮抗高糖诱导的SCs氧化应激和线粒体凋亡途径的激活。
