Anti-fatigue effects and mechanism of Syngnathus schlegeli peptides supplementation on exercise-fatigued mice

This study aims to investigate the anti-fatigue effect and mechanism of Syngnathus schlegeli peptides (SAP) on exercise-fatigued mice. Compared to the control group, SAP significantly reduced the accumulation of metabolites LA, BUN and MDA, increased the GSH-PX activity, inhibited oxidative stress, improved grip strength and prolonged swimming time in mice. Additionally, SAP enhanced the activity of CS, α-KGDHC, MRCC I and MRCC IV, Ca2+-Mg2+-ATPase and Na+-K+-ATPase in the gastrocnemius muscle, thereby improving mitochondrial function and increasing ATP production for energy supplementation. The anti-fatigue effect of SAP is associated with its promotion of protein expressions involved in the AMPK/PGC-1α and Keap1/NRF2 signaling pathway, as well as regulate the balance of intestinal microecology. Furthermore, DAELRMEKH was screened from the peptides identified from SAP by in silico and in vitro activity assays. The presence of hydrophobic and charged amino acids in DAELRMEKH facilitates better binding to the active pockets of AMPK and Keap1.