Egg components reverse the atrophy induced by injury in skeletal muscles

Skeletal muscle atrophy is the loss of muscle tissue caused by factors such as inactivity, malnutrition, aging, and injury. In this study, we aimed to investigate whether egg components exert inhibitory effects on muscle atrophy. An egg mix solution was orally administered for 10 consecutive days to male C57BL/6J mice injected with cardiotoxin in the tibialis anterior (TA) muscle. The administration of egg mixture significantly decreased the atrogin-1 and MuRF-1 protein levels, key factors in muscle atrophy, as observed by western blotting. Furthermore, we investigated the effects of egg components such as avidin, lecithin, biotin, 3-sn-phosphatidylcholine, and L-α-phosphatidylcholine on dexamethasone (DEX)-treated C2C12 myotubes. Lecithin, biotin, 3-sn-phosphatidylcholine, and L-α-phosphatidylcholine in egg yolk significantly recovered the diameters of C2C12 myotubes decreased upon DEX application. Avidin did not show such reversal. Biotin, 3-sn-phosphatidylcholine, and L-α-phosphatidylcholine also attenuated atrogin-1 protein expression enhanced by DEX. Our findings reveal that egg yolk components could contribute to the reversal of skeletal muscle atrophy induced by muscle injury.