A Flavonoid Concentrate from Lam. Leaves Extends Exhaustive Swimming Time by Improving Energy Metabolism and Antioxidant Capacity in Mice.

Lam. leaves contain various nutrients and bioactive compounds. The present study aimed to assess the anti-fatigue capacity of a flavonoids concentrate purified from Lam. leaves. The total flavonoids in the purified extract were analyzed by ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-MS/MS). The mice were supplemented with purified Lam. leaf flavonoid-rich extract (MLFE) for 14 days. The weight-loaded forced swimming test was used for evaluating exercise endurance. The 90-min non-weight-bearing swimming test was carried out to assess biochemical biomarkers correlated to fatigue and energy metabolism. UPLC-MS/MS analysis identified 83 flavonoids from MLFE. MLFE significantly increased the swimming time by 60%. Serum lactate (9.9 ± 0.9 vs. 8.9 ± 0.7), blood urea nitrogen (BUN) (8.8 ± 0.8 vs. 7.2 ± 0.5), and nonesterified fatty acid (NEFA) (2.4 ± 0.2 vs. 1.7 ± 0.3) were significantly elevated; , , and mRNA expression were significantly downregulated; and mRNA expression was significantly upregulated in muscle after swimming. MLFE supplement significantly decreased serum lactate (8.0 ± 1.0 vs. 9.9 ± 0.9), BUN (8.6 ± 0.4 vs. 8.9 ± 0.8), and NEFA (2.3 ± 0.4 vs. 2.4 ± 0.2) and increased the protein and mRNA expression of , , and . The enhancement of glucose metabolism and antioxidant function by MLFE contributes partly to its anti-fatigue action.