小麦肽改善慢性疲劳综合征大鼠认知功能障碍

Wheat Peptide Ameliorates Cognitive Impairment of Chronic Fatigue Syndrome Rats

目的:探讨小麦肽对慢性疲劳综合征(chronic fatigue syndrome,CFS)大鼠认知能力的改善作用与机制。方法:70只雄性SD大鼠随机选取10只作为正常对照组(N),其余SD大鼠通过慢性束缚结合冷水力竭游泳的方式构建CFS大鼠模型,然后将CFS模型大鼠随机分为模型对照组(M)、低剂量小麦肽喂养组(M+L)、中剂量小麦肽喂养组(M+M)和高剂量小麦肽喂养组(M+H)。M+L、M+M以及M+H组大鼠分别灌胃给予剂量为0.2、0.4、0.8 g/(kg m_(b)·d)小麦肽,N组与M组大鼠均给予同等体积生理盐水,每天1次。经过8周饮食干预后,采用水迷宫实验考察大鼠认知能力;水迷宫实验结束后处死大鼠,采用酶联免疫吸附试验法检测大鼠血清神经细胞因子以及Th1型和Th2型细胞因子的水平,海马组织中氧化应激水平和5-羟色胺(5-hydroxy tryptamine,5-HT)含量。结果:与N组相比,CFS模型大鼠的逃避潜伏期时间及丙二醛、色氨酸、5-HT、Th2细胞因子白细胞介素(interleukin,IL)-4和IL-10水平均显著增加(P<0.05),穿越平台象限次数和平台逗留时间、超氧化物歧化酶活力、神经生长因子和脑源性神经营养因子浓度以及Th1细胞因子肿瘤坏死因子β、干扰素γ水平显著降低(P<0.05)。而经8周口服小麦肽干预后,CFS大鼠上述指标得到显著改善。结论:口服小麦肽可通过激活抗氧化系统、调节神经细胞因子分泌以及促进Th2型向Th1型细胞免疫反应转变而有效地改善CFS大鼠认知功能。

Objective:To investigate the effect and mechanism of wheat peptide on improving cognitive capacity in chronic fatigue syndrome rats.Methods:A total of 70 male SD rats were used in this study.From these,ten were randomly selected as a normal control group(N),and the other 60 rats were used to construct an animal model of chronic fatigue syndrome(CFS)by chronic restraint combined with exhaustive swimming in cold water.Then,they were randomly divided into a model control group(M),a low-dose wheat peptide group(M+L),a medium-dose wheat peptide group(M+M)and a high dose wheat peptide group(M+H).The rats in the M+L,M+M and M+H groups were orally administrated with wheat peptide at daily doses of 0.2,0.4 and 0.8 g/(kg m_(b)·d)body mass for eight consecutive weeks,respectively.After this,water maze test was carried out to evaluate the cognitive capacity of experimental rats.After completion of the test,the rats were killed to collect serum for detecting the levels of tryptophan,nerve growth factor(NGF)and brain-derived neurotropic factor(BDNF),and Th1 and Th2 cytokines by enzyme-linked immunosorbent assay(ELISA),and the level of oxidative stress and the content of 5-hydroxy tryptamine(5-HT)in hippocampus tissues were measured as well.Results:Compared with the control group,the escape latency,and the serum levels of MDA,tryptophan,5-HT and Th2 cytokines(interleakin(IL)-4 and IL-10)in the CFS model rats were significantly increased(P<0.05).On the contrary,the number of times that the rats crossed the platform quadrant,the time spent in the platform quadrant,superoxide dismutase activity,and the levels of nerve growth factor and brain-derived neurotropic factor and Th1 cytokines(TNF-βand IFN-γ)all significantly decreased(P<0.05).All these symptoms were significantly improved after eight weeks of oral administration of wheat peptide intervention.Conclusion:Oral administration of wheat peptide can effectively improve cognitive function in CFS rats by activating the antioxidant system,regulating the secretion of neurocytokines and promoting cellular immune response resulting from the transformation from Th2-type cytokines to Th1-type cytokines.