Anti-fatigue effect of quercetin on enhancing muscle function and antioxidant capacity.

The aim of this study was to evaluate the anti-fatigue effect of quercetin in mice. Three-week-old male BALB/c mice, fed with/without 0.005% quercetin for 6 weeks, were randomly divided into two experimental sets (loaded swimming and non-loading swimming tests). Our data indicated that dietary quercetin supplementation prolonged the exhaustive swimming time. In addition, lactic acid (LD) and blood urea nitrogen (BUN) levels, lactate dehydrogenase (LDH) and creatine kinase (CK) activities in serum were significantly decreased, while the levels of non-esterified free fatty acids (NEFA) in serum and the content of liver glycogen and muscle glycogen were significantly enhanced in dietary quercetin supplementation group. Furthermore, dietary quercetin supplementation significantly enhanced the glutathione peroxidase (GPx) and catalase (CAT) activities in serum, liver and gastrocnemius muscle and enhanced the total superoxide dismutase (T-SOD) activity in gastrocnemius muscle, but decreased the malondialdehyde (MDA) content and reactive oxygen species (ROS) level. Meanwhile, dietary quercetin supplementation affected the mRNA expression of regulators factors involved in muscle damage and inflammation, glucose metabolism and gluconeogenesis, muscle mitochondrial fatty acid β-oxidation and antioxidant related genes. Together, our data confirm that dietary quercetin supplementation can promote anti-fatigue capacity by promoting the antioxidant capacity and glycogen storage, as well as enhancing muscle function. PRACTICAL APPLICATIONS: Quercetin is a natural polyphenolic flavonoid substance. Here we confirm that quercetin has anti-fatigue activity. Our study indicates that quercetin may be used as natural anti-fatigue functional food or drugs.