Anti-Fatigue Activity of Aqueous Extracts of L. in Exercise Trained Mice.

L. is a nutritious vegetable and herbal medicine that is consumed worldwide. The aim of this study was to evaluate the anti-fatigue effects and underlying effects of aqueous extract of L. (SA). Male C57BL/6 mice from four groups designated vehicle, exercise, exercise with low dose (250 mg/kg) or high dose of SA (500 mg/kg), were trained by swimming exercise and orally administrated with SA every other day for 28 days. The anti-fatigue activity was determined by exhaustive swimming test, as well as the muscle structure, levels of blood hemoglobin, and metabolites including lactate and urea nitrogen. SA alleviated mice fatigue behaviors by eliminating metabolites, while improving muscle structure and hemoglobin levels. Moreover, SA enhanced glycogen synthesis of liver but not muscle via increasing GCK and PEPCK gene expressions. Importantly, SA improved antioxidant enzymes expression and activities in both liver and muscle, which was possibly related to its primary components polysaccharides and the antioxidant components including chlorogenic acid, luteolin, and chicoric acid. Taken together, the anti-fatigue effects of SA could be partly explained by its antioxidant activity and mediating effects on glycogen synthesis and metabolites elimination. Therefore, SA could be a potential nutraceutical for improving exercise performance and alleviating physical fatigue.