Spirulina are multicellular and filamentous cyanobacteria that have achieved considerable popularity in the health sector, food industry, and aquaculture. In the present study, we aimed to evaluate the antifatigue effects of Spirulina-derived peptides on Institute for Cancer Research mice and explore the association between antifatigue activity and fat metabolism involving the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway. We extracted the peptides from Spirulina by enzymatic hydrolysis and ultrafiltration. The mice were orally administered with Spirulina peptides (0.125, 0.5, and 2 mg/g bw/day) daily for 4 weeks. We found that Spirulina peptides, especially the high-dose group, significantly prolonged the swimming time by 126.1%, increased the activities of antioxidant enzymes, and decreased the content of malondialdehyde by 60.2% compared with the glutathione (GSH) group. The levels of some indicators of exercise fatigue, including lactic dehydrogenase, blood lactic acid, and creatine phosphokinase, were reduced. In the high-dose group, these indicators were reduced by 40.7%, 22.3%, and 11.3% compared with the GSH group. Spirulina peptides did not excessively consume blood sugar or glycogen in the liver and muscle to produce energy. However, the triglyceride level was reduced, and the level of free fatty acids was increased. Besides, the proteins in the AMPK signaling pathway were activated. Taken together, these findings indicated that Spirulina peptides could effectively alleviate physical fatigue by reducing the production of lactic acid and improving antioxidant capacity. Spirulina peptides also helped increase the energy resources by activating the AMPK signaling pathway to utilize fat metabolism.

螺旋藻是多细胞和丝状蓝细菌，在健康领域，食品工业和水产养殖中已获得相当大的普及。在本研究中，我们旨在评估螺旋藻衍生肽对癌症研究所小鼠的抗疲劳作用，并探讨抗疲劳活性与涉及单磷酸腺苷激活的蛋白激酶（AMPK）信号传导途径的脂肪代谢之间的关系。我们通过酶促水解和超滤从螺旋藻中提取了肽。每天给小鼠口服螺旋藻肽（0.125、0.5和2 mg / g bw /天），持续4周。我们发现螺旋藻与谷胱甘肽（GSH）组相比，肽，特别是高剂量组，显着延长了游泳时间126.1％，增加了抗氧化酶的活性，并使丙二醛含量降低了60.2％。降低了运动疲劳的某些指标，包括乳酸脱氢酶，血液乳酸和肌酸磷酸激酶。与GSH组相比，高剂量组的这些指标分别降低了40.7％，22.3％和11.3％。螺旋藻肽不会过度消耗肝脏和肌肉中的血糖或糖原来产生能量。但是，甘油三酸酯水平降低，游离脂肪酸水平升高。此外，AMPK信号通路中的蛋白质也被激活。综上所述，这些发现表明：螺旋藻肽可通过减少乳酸的产生并提高抗氧化能力来有效缓解身体疲劳。螺旋藻肽还通过激活AMPK信号通路来利用脂肪代谢，从而帮助增加了能量资源。