Abstract:[Objective]This study aimed to explore the antioxidant and anti-fatigue properties of Malus spectabilis fruit polysaccharides (MPPs) and analyze the structure-activity relationships.[Method]Two types of MPPs were prepared via acidic (AC-MPC) and alkaline (AL-MPC) extraction methods. The polysaccharide composition was identified by high-performance anion-exchange chromatography (HPAEC). The changes in mouse body mass, serum biochemical indicators, and exhaustive swimming time were measured to assess the in vivo antioxidant and anti-fatigue effects of MPPs.[Result]Galacturonic acid was the main component in both types of MMPs, while AL-MPC had higher mass fraction of total polysaccharides. The in vivo experiments demonstrated that both types of MMPs possessed significant antioxidant and anti-fatigue activities. In particular, AL-MPC showcased better performance. Compared with the control group, high-dose AL-MPC substantially enhanced the antioxidant enzyme activities and reduced the malondialdehyde (MDA) level in the mouse liver. In addition, AL-MPC significantly prolonged the exhaustive swimming time of mice and reduced the blood urea nitrogen (BUN), lactic acid (LA), and lactate dehydrogenase (LDH) levels.[Conclusion]MMPs have significant antioxidant and anti-fatigue activities. Especially, AL-MPC exhibits more excellent bioactivity due to its unique structural features. This study provides a scientific basis and potential raw materials for the value-added utilization of Malus spectabilis fruits and the development of functional foods.
