火把花根多糖对运动疲劳小鼠AMPK/mTOR信号通路的影响

Effects of tripterygium hypoflaucum(Levl.)hutch polysaccharide on the AMPK/mTOR signal pathway in mice with exercise-induced fatigue

目的研究火把花根多糖的抗运动疲劳作用及可能的作用机制。方法24只ICR雄性小鼠按随机数字表法分为静止对照组、疲劳对照组、疲劳+单糖组和疲劳+火把花根多糖组,每组6只。疲劳+火把花根多糖组给予20 g/L火把花根多糖受试液,疲劳+单糖组给予20 g/L单糖混合物受试液,静止对照组和疲劳对照组给予纯化水,各组均按20 mL/kg每日灌胃给药1次,连续14 d。观察给药期间小鼠体质量、摄食量、饮水量等一般情况;在给药第6、13天进行疲劳转棒实验,记录小鼠疲劳转棒时间;给药第14天进行力竭游泳实验,记录小鼠力竭游泳时间;小鼠力竭游泳后即相应取材进行血清的三酰甘油(TG)、血糖(GLU)检测,行左侧腓肠肌HE染色和糖原(PAS)染色观察病理变化,右侧腓肠肌采用实时荧光定量PCR(qPCR)方法检测腺苷酸活化蛋白激酶(AMPK)、哺乳动物雷帕霉素靶蛋白(mTOR)、葡萄糖转运蛋白4(GLUT-4)mRNA表达水平。结果给药第13天,相比静止对照组,疲劳+火把花根多糖组的体质量减轻(P<0.05)。其余各时间点各组的体质量、摄食量、饮水量的差异均无统计学意义(P>0.05)。相比疲劳对照组,疲劳+火把花根多糖组在给药第6天时疲劳转棒时间增加不显著(P>0.05),而在给药第13天时,其疲劳转棒时间显著增加(P<0.05),且在给药第14天时其力竭游泳时间亦增加(P<0.05)。HE染色未见明显异常,PAS染色可见疲劳对照组与疲劳+单糖组腓肠肌着色略深,而疲劳+火把花根多糖组着色最深。与疲劳对照组比较,疲劳+火把花根多糖组的TG差异无统计学意义,GLU降低,而AMPK、mTOR、GLUT-4 mRNA表达水平显著上调(P<0.05)。结论火把花根多糖具有抗运动疲劳的作用,其机制可能与调节AMPK/mTOR信号通路的糖代谢有关。

Objective To study the effect and possible mechanism of polysaccharide from tripterygium hypoflaucum(Levl.)hutch on exercise-induced fatigue in mice.Methods Twenty-four ICR mice were randomly divided into the static control group,the fatigue control group,the fatigue+monosaccharide group and the fatigue+tripterygium hypoflaucum(Levl.)hutch polysaccharide group,with 6 mice in each group.The fatigue+tripterygium hypoflaucum(Levl.)hutch polysaccharide group was given 20 g/L aqueous solution of tripterygium hypoflaucum(Levl.)hutch polysaccharide,the fatigue+monosaccharide group was given 20 g/L aqueous solution of monosaccharide mixture,and the static control group and the fatigue control group were given purified water.Each group was given intervention 20 mL/kg by gavage once a day for 14 days.The body mass,food intake,water consumption and other general conditions of mice were observed during administration.On the 6th day and the 13th day of administration,mice were evaluated by rotary rod fatigue tester,and on the 14thday of administration,the exhaustive swimming experiment was carried out.After exhaustive swimming,the serum levels of triglyceride(TG)and blood glucose(GLU)were detected.The pathological changes of left gastrocnemius muscle were observed by HE staining and Periodic Acid-Schiff staining(PAS).The expression levels of AMP-activated protein kinase(AMPK),mammalian target of rapamycin(mTOR)and glucose transporter 4(GLUT-4)mRNA were observed by realtime fluorescence quantitative PCR(qPCR).Results After treatment for 13 days,compared with the static control group,the body mass was decreased in the fatigue+tripterygium hypoflaucum(Levl.)hutch polysaccharide group(P<0.05).There were no significant differences in body mass,food intake and water consumption at other time points between the four groups(P>0.05).Compared with the fatigue control group,there was no significant increase in the rotating rod lasting time after treatment for 6 days in the fatigue+tripterygium hypoflaucum(Levl.)hutch polysaccharide group(P>0.05),but it increased significantly on the 13th day of administration(P<0.05).The exhaustive swimming time significant increased after treatment for 14 days in the fatigue+tripterygium hypoflaucum(Levl.)hutch polysaccharide group(P<0.05).HE staining showed no obvious abnormality,PAS staining showed that the gastrocnemius muscle was slightly darker in the fatigue control group and the fatigue+monosaccharide group,while the colour was the deepest in the fatigue+tripterygium hypoflaucum(Levl.)hutch polysaccharide group.Compared with the fatigue control group,there was no significant difference in TG,the GLU decreased in the fatigue+tripterygium hypoflaucum(Levl.)hutch polysaccharide group(P<0.05),while the expression levels of AMPK,mTOR and GLUT-4 mRNA were significantly increased(P<0.05).Conclusion The tripterygium hypoflaucum(Levl.)hutch polysaccharide has the effect of anti-exercise-induced fatigue in mice,and its mechanism may be related to the glucose metabolism regulated by AMPK/mTOR signal pathway.