该文研究了不同分子量紫菜多糖酶解片段协同牡蛎肽改善运动疲劳的作用。将小鼠随机分为正常组（N）、运动组（M）、牡蛎肽组（O）及牡蛎肽联合高、中、低分子量紫菜多糖酶解片段组（OH、OM、OL），连续干预16 d。结果表明，相较于单一牡蛎肽干预，紫菜多糖酶解片段协同牡蛎肽具有更好的抗疲劳活性，OH、OM、OL组小鼠的游泳力竭时间分别提高了60.77%、37.25%、37.59%；OH组小鼠肝脏AST、ALT水平分别降低了12.88%、11.39%，血清CK、LDH活力分别显著降低了22.02%、8.99%，运动引起的肝脏和骨骼肌损伤得到改善。此外，干预组小鼠肝糖原含量增加，血清乳酸和尿素氮水平降低，氧化应激水平改善。机制分析表明，紫菜多糖酶解片段协同牡蛎肽可以上调骨骼肌中PGC1α/TFAM信号通路；增加有益菌Lactococcus的丰度，降低致病菌Staphylococcus、Acinetobacter、Oscillospira和Ruminococcus的丰度。总之，紫菜多糖酶解片段协同牡蛎肽通过促进线粒体生物发生和调节肠道菌群改善小鼠运动疲劳，其中高分子量紫菜多糖酶解片段（Mw=267.3 ku）效果较优，本研究为紫菜产品的开发提供了理论依据。

In this paper, the effects of different molecular weight enzymatic fragments of Porphyra polysaccharide synergizing with oyster peptide on improving exercise fatigue were studied. Mice were randomly divided into normal group (N), exercise group (M), oyster peptide group (O), and oyster peptide with high, medium, and low molecular weight enzymatic fragments of Porphyra polysaccharide group (OH, OM, OL), and continuous intervention for 16 d. The results showed that, compared with the single oyster peptide intervention, enzymatic fragments of Porphyra polysaccharide synergizing with oyster peptide had better anti-fatigue activity, in OH, OM, OL groups, the swimming exhaustion times of mice increased by 60.77%, 37.25%, 37.59%, respectively; the hepatic AST and ALT levels of mice in the OH group were reduced by 12.88% and 11.39%, respectively, and serum CK and LDH activity of mice were significantly reduced by 22.02% and 8.99%, respectively, suggesting that exercise-induced hepatic and skeletal muscle injuries were improved. Additionally, in intervention groups, hepatic glycogen contents were increased, serum lactate and urea nitrogen levels were decreased, and oxidative stress levels were improved in mice. Mechanism analysis showed that the enzymatic fragments of Porphyra polysaccharide synergizing with oyster peptide could up-regulate PGC1α/TFAM signaling pathway in skeletal muscle; increase the abundance of beneficial bacteria Lactococcus and decrease the abundance of pathogenic bacteria Staphylococcus, Acinetobacter, Oscillospira, and Ruminococcus. In conclusion, enzymatic fragments of Porphyra polysaccharide synergizing with oyster peptide improved exercise fatigue in mice by promoting mitochondrial biogenesis and regulating intestinal flora, among which the high-molecular-weight enzymatic fragment of Porphyra polysaccharide (Mw=267.3 ku) showed better effect. This study provides a theoretical basis for the development of Porphyra products.

国家重点研发计划项目