Effect of lemon seed flavonoids on the anti‐fatigue and antioxidant effects of exhausted running exercise mice

In this research, mice were gavaged with different doses of lemon seed flavonoids (LSF) for 4 weeks, and vitamin C was used as a positive control to investigate its effects on anti-fatigue and antioxidant capacity in exhaustively exercised mice. The results obtained from the study indicated that both vitamin C and LSF could significantly increase the running exhaustion time of mice, and the exhaustion time of mice was prolonged with increasing LSF concentration. LSF can increase hepatic glycogen and the free fatty acid content and reduce the lactate and urea nitrogen contents in a dose-dependent manner in mice. Serum CK, AST, and ALT levels in mice decreased gradually with increasing LSF concentration. LSF increased SOD and CAT levels and decreased MDA levels in mice in a dose-dependent manner. LSF could also enhance nNOS, eNOS, and ASCT1 mRNA expression and decrease syncytin-1, iNOS and TNF-α expression in the skeletal muscle of mice. By HPLC analysis, LSF was found to contain epigallocatechin, caffeic acid, epicatechin, vitexin, quercetin, and hesperidin, which are common flavonoids of this species. Thus, it was observed that LSF has good anti-fatigue and antioxidant capacities, and its anti-fatigue effect is related to improving the hepatic glycogen reserve capacity, increasing fat mobilization, and reducing lactate accumulation and protein decomposition. The antioxidant capacity of LSF is related to scavenging free radicals and reducing lipid peroxidation, and its antioxidant effect comes from its five antioxidant flavonoids. In conclusion, LSF has high development and application prospects in nutritional supplements. Practical applications Lemon seed is the waste of lemon processing, which contains abundant flavonoids. The flavonoids in lemon seed can be used to exert its antioxidant effect and recover from exhausted exercise. Therefore, it can be concluded that lemon seed flavonoids are functional components that can be used as exercise recovery substances.