8-Week Extract Administration Improves Submaximal Exercise Capacity in Mice by Enhancing Skeletal Muscle Antioxidant Gene Expression and Plasma Antioxidant Capacity.

Black ginger () extract (KPE) is extracted from a ginger family plant grown in Thailand. The polyphenolic components have potential antioxidant effects and have been reported to enhance exercise performance. However, the impact of long-term KPE administration combined with long-term training on the endurance exercise performance of healthy individuals has not been fully studied. In this study, a healthy mouse model was used to investigate the effects of 8 weeks KPE administration and voluntary wheel running on the submaximal endurance exercise capacity and its mechanism. The results showed that 8 weeks of KPE administration significantly enhanced the submaximal endurance exercise capacity of mice and extended the daily voluntary wheel running distance. By measuring oxidative stress markers in plasma and the mRNA expression of antioxidant genes in skeletal muscle, we found that KPE significantly increased plasma antioxidant levels and activated the Nrf2 (Nuclear factor erythroid 2-related factor 2)/ARE (Antioxidant Response Element) pathway and its downstream antioxidant genes expression in skeletal muscle. These results suggest that KPE may enhance the antioxidant capacity of plasma and skeletal muscle by activating the Nrf2-ARE-centered antioxidant pathway, thereby increasing the daily running distance and improving the submaximal endurance exercise capacity of mice.