人参总皂苷对尾吊模拟微重力大鼠学习记忆损伤和焦虑的保护作用

目的:通过人参总皂苷干预尾吊大鼠,检测大鼠在水迷宫、高架十字迷宫中的表现以及下丘脑-垂体-肾上腺(HPA)轴、炎症因子以及色氨酸通路的相关因子表达,探讨人参总皂苷对尾吊大鼠学习记忆损伤及焦虑的影响。方法:将Wistar雄性大鼠分为正常组,尾吊模型组,石杉碱甲组(0.1 mg·kg^-1),人参总皂苷低、高剂量组(100,200 mg·kg^-1),每组8只。除正常组组外,其余组大鼠均24 h保持-30°尾部悬吊状态。正常组与模型组给予纯净水灌胃,灌胃体积为10 mL·kg^-1,连续灌胃给药28 d后进行水迷宫和高架十字迷宫行为学检测。检测结束后腹主动脉取血,冰上剥离大鼠脑皮层,液氮猝灭,-80℃保存备用。采用液质联用(LC-MS/MS)检测大鼠脑皮层中多巴胺,乙酰胆碱,谷氨酸,γ-氨基丁酸的神经递质水平以及色氨酸通路代谢物(色氨酸,5-羟色胺,5-羟吲哚乙酸,犬尿氨酸,3-羟基犬尿氨酸,犬尿喹啉酸)。采用酶联免疫吸附测定(ELISA)试剂盒检测大鼠血清中炎症因子白细胞介素-6(IL-6),白细胞介素-10(IL-10)水平以及HPA轴相关激素促肾上腺皮质激素(ACTH),水平皮质酮(CORT)水平。结果:与正常组比较,模型组在水迷宫中逃避潜伏期显著性升高,穿台次数显著性降低,在高架十字迷宫中开臂进入次数与开臂进入次数百分比明显降低(P<0.05,P<0.01),皮层中多巴胺,乙酰胆碱,谷氨酸,γ-氨基丁酸含量降低,犬尿氨酸,犬尿喹啉酸成上升趋势,3-羟基犬尿氨酸,5-羟色胺,5-羟吲哚乙酸呈下降趋势,血清中IL-6,IL-10,ACTH,CORT水平显著升高(P<0.05,P<0.01);与模型组大鼠比较,人参总皂苷低、高剂量组在水迷宫中逃避潜伏期降低,增加穿台次数及高架十字迷宫的开臂次数,大鼠的多巴胺,乙酰胆碱,谷氨酸,γ-氨基丁酸含量升高,犬尿氨酸,犬尿喹啉酸呈下降趋势,3-羟基犬尿氨酸,5-羟色胺,5-羟吲哚乙酸呈上升趋势及下调了IL-6,IL-10,ACTH,CORT水平(P<0.05,P<0.01)。结论:尾吊28 d模拟微重力可损害大鼠的学习记忆能力并出现焦虑样行为,人参总皂苷具有改善其学习记忆损伤和焦虑样行为的作用,其机制可能是主要与抑制机体炎症和调节HPA轴失衡有关。

Protective Effect of Total Ginsenoside Ginseng Root on Learning and Memory Impairment and Anxiety in Rats Induced by Hindlimb Suspension

Objective: To investigate the effect of total ginsenoside ginseng root on the learning and memory impairment and anxiety of hindlimb suspension rats by detecting the performance of rats in the water maze,elevated plus maze,and the expression of hypothalamic-pituitary-adrenal(HPA)axis,inflammatory factors and tryptophan pathway related factors through the intervention of ginsenosides in hindlimb suspension rats. Method: The Wistar male rats were divided into normal group,hindlimb suspension model group,Huperzine A group(0.1 mg·kg^-1),and total ginsenoside ginseng root low and high dose groups(100,200 mg·kg^-1),with 8 rats in each group. Except for the normal group,the rats in the other groups maintained a-30°hindlimb suspension state for 24 h. The normal group and the model group received intragastric administration of 10 mL·kg^-1 pure water. After 28 days of continuous administration,the water maze and elevated plus maze behavioral tests were performed. After the tests,blood was taken from the abdominal aorta,and the rat brain cortex was peeled off on ice,quenched with liquid nitrogen,and stored at-80 ℃ for later use. LC-MS/MS was used to detect neurotransmitter levels of dopamine, acetylcholine, glutamate, γ-aminobutyric acid and tryptophan pathway metabolites(tryptophan,5-hydroxytryptamine,5-hydroxyindoleacetic acid,kynurenine,3-hydroxykynurenine,and kynurenine)in rat brain cortex. An enzyme-linked immunosorbent assay(ELISA)kit was used to detect the levels of inflammatory factors interleukin-6(IL-6),interleukin-10(IL-10),the HPA axisrelated hormone corticotropin(ACTH),and the level of corticosterone(CORT). Result: Compared with the normal group,the escape latency in the water maze significantly increased,the number of crossings was significantly reduced,and the number of open-arm entry and the percentage of open-arm entry were significantly reduced in the elevated plus maze in model group(P<0.05,P<0.01),the content of dopamine,acetylcholine,glutamic acid,and γ-aminobutyric acid in the cortex decreased,kynurenine and kynurenic acid showed an upward trend,3-hydroxykynurenine,5-hydroxytryptamine,5-hydroxyindole acetic acid showed a downward trend,and the levels of IL-6,IL-10,ACTH,and CORT in the serum significantly increased(P<0.05,P<0.01).Compared with the model group of rats,total ginsenoside ginseng root low and high dose groups group reduced the avoidance latency in the water maze,and increased the number of crossings and the number of open arms of the elevated plus maze, dopamine, acetylcholine, glutamate, and γ-aminobutyl content increased, while kynurenine and kynurenic acid showed a downward trend, 3-hydroxykynurenine, serotonin, and 5-hydroxyindole acetic acid showed an upward trend,and IL-6,IL-10,ACTH,and CORT factor levels were down-regulated(P<0.05,P<0.01). Conclusion: Hindlimb suspension for 28 days in simulated microgravity can impair the learning and memory ability of rats and cause anxiety-like behaviors. Total ginsenoside ginseng root can improve their learning and memory impairment and anxiety-like behaviors. The mechanism may be mainly related to inhibiting body inflammation and regulating HPA axis imbalance.