The antifatigue effect of scallop male gonad powders via alleviating oxidative stress and modulating inflammatory cytokines in mice

The scallop male gonad (SMG) is the primary edible byproduct of the scallop P. yessoensis during scallop adductor muscle processing. SMG powders showed obvious antifatigue effects in a dose-dependent manner from 50-200 mg/kg/d, as reflected by a 40%-80% increase in exhausted swimming time and a 10%-90% increase in glucose, liver glycogen, and muscle glycogen content compared to those of the Con-S group. Moreover, the SMG powders could maintain the orderly arrangement of muscle tissue after acute vigorous exercise. Moreover, compared with those in the Con-S group, the SMG powders alleviated oxidative stress, as reflected by the downregulation of NAD+/NADH in muscle tissue and the increase in ATP content in muscle tissue by 0.2-fold and SOD content in serum by 0.1-fold. Additionally, protein and amino acid decomposition was alleviated, as reflected by a 14%-22% decrease in BUN as the amount of SMG powder increased. The 10%-12% decrease in the accumulation of BLA in the SMG-treated group corresponded well to the 11%-20% decrease in the LDH level in the serum. In addition, SMG powders downregulated the inflammatory cytokines IL-1β and IL-6 by 35% and 46%, respectively, compared with those in the Con-S group at a dose of 200 mg/kg/d. The antifatigue-related signaling pathways PI3K/AKT, NF-κB, and NRF2/HO-1 could be well regulated by SMG, which could be associated with high antioxidant-related amino acid contents (25.76%) and branched-chain amino acid contents (14.61%) in SMG, indicating that the development of food administration could increase exercise tolerance.