Ursolic Acid Improves Physical Fatigue through Regulating Oxidative Stress and Energy Metabolism in Mice

Ursolic acid has been extensively reported to possess beneficial properties on muscle function. However, the effect and mechanism of Ursolic acid on physical fatigue has not yet been investigated. Our study was to explore relevance between fatigue and ursolic acid, and clarify its potential biological protective properties in excessive exercise-induced physical fatigue. The mouse model of physical fatigue was constituted by forced swimming test. The experiment mice were fed with ursolic acid by gastric perfusion for 28 successive days. The exhaustive exercise time, fatigue related biochemical indicators, oxidative stress, energy metabo-lism, and mitochondrial biogenesis were detected to estimate the effects of ursolic acid on physical fatigue. The presented results showed that ursolic acid significantly alleviated CK, LDH, BUN, BLA, muscle glycogen and liver glycogen level after excessive exercise-induced fatigue. Moreover, ursolic acid significantly increased SOD activity and reduced MDA content to alleviate oxidative stress in skeletalmuscle. In addition, ursolic acid significantly enhanced the activity of SDH and Na+-K+-ATPase to improve energy metabolism. Lastly, ursolic acid significantly augmented mTFA mRNA expression to ameliorate mitochondrial biogenesis effect. These results proved treatment with ursolic acid possessed the beneficial properties on tissue injury, oxidative stress, energy metabolism and mitochondrial biogenesis function in muscle, which suggested ursolic acid could be used as a potential functional candidate to delay fatigue.