Abstract
The fatigue spreads among the people who live under stressful life and brings about a negative impact on physical function. Here we evaluated the anti-fatigue effects of fermented porcine placenta (FPP) and main constituents, lysine (Lys) and leucine (Leu) with treadmill stress test and forced swimming test (FST) in animal models. The mice were administrated with FPP, Lys, and Leu for 21 days. After treadmill exercise, FPP, Lys, and Leu significantly reduced fatigue-related biochemical parameters, including lactate, lactate dehydrogenase, glucose, creatine kinase, urea nitrogen, cortisol, and pro-inflammatory cytokines, whereas superoxide dismutase activity and glycogen levels were significantly increased by FPP, Lys, and Leu. In the FST, FPP, Lys, and Leu significantly decreased immobility times and up-regulated brain-derived neurotrophic factor expression in brain. Furthermore, FPP, Lys, and Leu significantly decreased production of tumor necrosis factor-α, interleukin (IL)-6, IL-1β, and IL-4 through blockade of caspase-1/nuclear factor-κB pathway in stimulated splenocytes. In addition, FPP, Lys, and Leu significantly promoted proliferation of splenocytes. In conclusion, these findings suggest the potential of FPP as a novel functional food for the regulation of fatigue.