Anti-fatigue potential of Pinus koraiensis leaf extract in an acute exercise-treated mouse model

Pinus koraiensis leaf (PKL) extract exerts antihyperlipidemic, antidiabetic, and anticancer effects; however, its anti-fatigue properties have not been elucidated to date. In this study, the anti-fatigue properties of PKL were evaluated by assessing the endurance of mice by a weight-loaded forced swimming (WLFS) and rotarod (RR) tests. Subsequently, various behavioral, biochemical, and physiological parameters were measured. Treatment with PKL decreased hepatic and muscular glycogen levels in mice subjected to WLFS and RR test compared to those in acute exercise-treated (AET) mice. Additionally, plasma levels of stress-related biochemical factors (lactate, lactate dehydrogenase, aminotransferase, aspartate aminotransferase, and blood urea nitrogen) decreased significantly (P < 0.05), whereas the levels of superoxide dismutase and glutathione peroxidase increased. Furthermore, PKL potentially improved mental fatigue by decreasing corticosterone and increasing serotonin levels. PKL increased the expression of phosphorylated cyclic adenosine-3',5'-monophosphate response element-binding protein and brain-derived neurotrophic factor in the hippocampus. Collectively, the anti-fatigue effects of PKL could be explained by its antioxidant activity, mediating effects on glycogen synthesis, and control over stress. In conclusion, the findings of the present study suggest that PKL is a potential nutraceutical for improving exercise performance and alleviating fatigue.