海参粗多肽对小鼠运动疲劳及肠道菌群的影响

Effects of Sea Cucumber Crude Peptides on Exercise Fatigue and Gut Microbiota in Mice

摘要:

为评估海参粗多肽(SCP)对小鼠运动疲劳及肠道菌群失衡的调节作用,以海参(Apostichopus japonicus)为原料制备SCP。将6周龄雄性C57BL/6J小鼠分为4组,分别为正常(Control)组、运动疲劳(EF)组、SCP组及β-烟酰胺单核苷酸(NMN)对照组。通过负重游泳、握力实验和转棒实验评价小鼠的运动耐力；通过旷场实验和高架十字迷宫实验评估小鼠运动疲劳诱导的焦虑样行为；采集小鼠肌肉、血清和粪便样本,分别用于H&E染色、生化指标检测、RT-qPCR和16S rRNA测序分析。结果表明:与Control组相比,EF组小鼠运动耐力显著下降,焦虑样行为明显增加；血清丙氨酸氨基转移酶、天冬氨酸氨基转移酶、尿素氮、肌酐、肌酸激酶、白细胞介素-6及白细胞介素-1β水平显著升高,小鼠睾酮与皮质醇比值显著下降。与EF组相比,补充SCP和NMN均可显著延长小鼠负重游泳力竭时间、增加小鼠握力,并延长转棒停留时间；旷场实验和高架十字迷宫实验结果显示,补充SCP和NMN可改善运动疲劳小鼠焦虑样行为；同时,SCP可降低小鼠血清尿素氮和肌酸激酶水平。RT-qPCR实验结果表明,SCP可上调AMPKα1、AMPKα2和PGC-1α的mRNA表达水平,并下调TLR4、MyD88及p65的mRNA表达水平。16S rRNA测序结果显示,与Control组相比,EF组小鼠肠道中Parasutterella和Erysipelotrichaceae等潜在有害菌相对丰度升高,而Muribaculaceae、Lactobacillaceae及Akkermansiaceae等益生菌相对丰度下降；与EF组相比,SCP干预可使Muribaculaceae和Akkermansiaceae的相对丰度升高。SCP可增强小鼠运动耐力、减轻肌肉损伤,改善由运动疲劳诱导的焦虑样行为；SCP可能通过调节肠道菌群结构发挥抗疲劳作用。希望研究可为SCP在抗疲劳功能食品中的开发与应用提供新的思路。

Abstract:

To evaluate the regulatory effects of sea cucumber crude peptides (SCP) on exercise fatigue and gut microbiota dysbiosis in mice, SCP was prepared from sea cucumber (Apostichopus japonicus). Six-week-old male C57BL/6J mice were divided into four groups:Control group, exercise fatigue (EF) group, SCP group, and β-nicotinamide mononucleotide (NMN) group. Exercise endurance was assessed by weighted swimming, grip strength, and rotarod tests. Anxiety-like behaviors induced by exercise fatigue were evaluated using the open-field test and elevated plus maze tests. Muscle, serum, and fecal samples were collected for H&E staining, biochemical analysis, RT-qPCR, and 16S rRNA sequencing. The results showed that, compared with the Control group, mice in the EF group exhibited significantly decreased exercise endurance and markedly increased anxiety-like behaviors. Serum levels of alanine aminotransferase, aspartate aminotransferase, urea nitrogen, creatinine, creatine kinase, interleukin-6, and interleukin-1β were significantly elevated, while the serum testosterone/cortisol ratio in EF mice was significantly decreased. Compared with the EF group, supplementation with SCP and NMN significantly prolonged the weighted swimming exhaustion time and increased grip strength and rotarod retention time in mice. The open-field and elevated plus maze tests showed that SCP and NMN supplementation improved anxiety-like behaviors in mice with exercise fatigue. Meanwhile, SCP reduced serum urea nitrogen and creatine kinase levels in mice. RT-qPCR results showed that SCP upregulated the mRNA expression levels of AMPKα1, AMPKα2 and PGC-1α and downregulated the mRNA expression levels of TLR4, MyD88, and p65. The 16S rRNA sequencing results showed that, compared with the Control group, the relative abundance of potentially harmful bacteria, such as Parasutterella and Erysipelotrichaceae, was increased in the gut of EF mice, whereas the relative abundance of beneficial bacteria, including Muribaculaceae, Lactobacillaceae, and Akkermansiaceae, was decreased. Compared with the EF group, SCP intervention increased the relative abundance of Muribaculaceae and Akkermansiaceae. SCP enhanced exercise endurance, alleviated muscle injury, and improved anxiety-like behaviors induced by exercise fatigue in mice. In addition, SCP may exert anti-fatigue effects by regulating the gut microbiota structure. This study may provide new insights into the development and application of SCP in anti-fatigue functional foods.