莱茵衣藻细胞外囊泡对小鼠运动性疲劳的缓解作用

Alleviating Effect of Chlamydomonas reinhardtii-derived Extracellular Vesicles on Exercise Fatigue in Mice

摘要:

【目的】探究莱茵衣藻（Chlamydomonas reinhardtii）细胞外囊泡（CLEVs）的抗氧化活性及其对小鼠运动性疲劳的缓解作用，为微藻来源细胞外囊泡在运动营养领域的应用提供参考。【方法】采用超速离心法分离CLEVs，并通过体外和体内试验评价其抗氧化及抗疲劳作用。【结果】CLEVs呈典型杯状或碗状形态，平均粒径为（88.35±0.36） nm。CLEVs可有效清除DPPH和ABTS⁺自由基，且其体外抗氧化活性具有剂量依赖性。在H₂O₂诱导的氧化损伤模型中，CLEVs可提高超氧化物歧化酶（SOD）和还原型谷胱甘肽（GSH）水平，降低丙二醛（MDA）、乳酸脱氢酶（LDH）、肌酸激酶（CK）及乳酸（LA）水平，增加糖原储备。动物试验表明，CLEVs可显著延长负重游泳力竭时间，并通过上调Nrf2、下调Keap1的表达增强抗氧化防御。【结论】CLEVs可通过改善氧化应激、促进能量代谢和激活Nrf2/Keap1信号通路缓解运动性疲劳，在运动营养及抗疲劳产品开发中具有应用潜力。

Abstract:

[Objective]This study explored the antioxidant activity and exercise fatigue-alleviating effect of Chlamydomonas reinhardtii-derived extracellular vesicles (CLEVs), aiming to provide a reference for the application of microalgae-derived extracellular vesicles in the field of sports nutrition.[Method]CLEVs were isolated by ultracentrifugation, and their antioxidant and anti-fatigue effects were evaluated through in vitro and in vivo experiments.[Result]CLEVs exhibited typical cup- or bowl-shaped morphology with an average particle size of (88.35±0.36) nm. CLEVs demonstrated concentration-dependent antioxidant activity in vitro and effectively scavenged DPPH and ABTS⁺ free radicals. In the H₂O₂-induced oxidative damage model, CLEVs increased the levels of superoxide dismutase (SOD) and reduced glutathione (GSH), decreased the levels of malondialdehyde (MDA), lactate dehydrogenase (LDH), creatine kinase (CK), and lactic acid (LA), and promoted glycogen storage. Animal experiments showed that CLEVs significantly prolonged the load swimming time to exhaustion and enhanced the antioxidant defense by upregulating the expression of Nrf2 and downregulating the expression of Keap1.[Conclusion]CLEVs could alleviate exercise fatigue by ameliorating oxidative stress, promoting energy metabolism, and activating the Nrf2/Keap1 signaling pathway, demonstrating potential application in sports nutrition and the development of anti-fatigue products.