Anti-fatigue activity of purified flavonoids prepared from chestnut (Castanea mollissima) flower

Castanea mollissima Blume has been used to treat a variety of diseases in Chinese traditional medicine. This study was aimed to examine the anti-fatigue effect of purified Chestnut flower flavonoids (CFF) in mice and its underlying mechanisms using the weight-loaded swimming test. The study revealed that the content of total flavonoids in CFF was 754.20 mgRE/gdm, which identified six main types of flavonoids, myricetin-3-O-glucoside, quercetin-3-O-rutinoside, quercetin-O-glucoside, kaempherol-3-O-rutinoside, isorhamnetin-3-O-rutinoside, kaempferol, respectively. CFF showed excellent free radical scavenging and anti-fatigue effect. Notably, CFF significantly prolonged the swimming time of mice, while down-regulating the levels of lactate dehydrogenase (LDH), blood lactic acid (BLA), blood urea nitrogen (BUN), and creatine kinase (CK), and increasing liver and muscle glycogen. Meanwhile, CFF suppressed exercise-elicited oxidative stress through promoting the SOD activity and reducing the MDA level. Furthermore, CFF up-regulated PGC-1α and PPARα expression in mouse skeletal muscle. In conclusion, these findings indicate that CFF exerts an anti-fatigue effect presumably via energy reserves and oxidative stress inhibition.