The Physicochemical Properties and Anti-Fatigue Efficacy of a Polysaccharide-Rich Fraction Derived From Millettia speciosa Champ.

The root of Millettia speciosa Champ has been traditionally and widely used for anti-fatigue properties in folk culture. However, the active components and underlying mechanisms of M. speciosa's anti-fatigue efficacy are still unclear. Notably, polysaccharides are considered the primary component for anti-fatigue action in many traditional Chinese medicines. This study aimed to characterize the physicochemical properties of a polysaccharide-rich fraction from M. speciosa (MSCP) and investigate its anti-fatigue efficacy and underlying mechanisms. The results showed that MSCP was primarily composed of glucose, arabinose, and galactose in a ratio of 90.0:5.2:4.8 and contained two sugar-peaks with molecular weights of 19 544 and 13 166 Da. The behavioral tests showed that MSCP could effectively extend the exhaustive swimming time and running time in the exercise-induced fatigue model and combined stress-induced fatigue model in mice. Treatment with MSCP reduced levels of blood urea nitrogen, blood lactic acid, lactate dehydrogenase, creatine kinase, and malondialdehyde, while increasing levels of muscle glycogen, hepatic glycogen, and superoxide dismutase. Furthermore, MSCP modulated the gut microbiota, which potentially contributes to its anti-fatigue efficacy. Our research provides theoretical support for incorporating MSCP as a novel dietary supplement in functional foods designed to enhance anti-fatigue properties.