Fermented antler extract attenuates muscle atrophy by regulating the PI3K/Akt pathway and inflammatory response in immobilization-treated C57BL/6J mice

Muscle atrophy or muscle wasting, which is featured by reduced muscle function and mass, typically results from disuse, aging, and chronic diseases. The deer antler, which refers to the young and non-ossified antlers of various species of deer-related animals, is not fully calcified and comprises of densely growing hair. Here, we investigated whether Bacillus subtilis-fermented antler extract (FAE) inhibits immobilization-induced muscle atrophy in C57BL/6J mice. Oral administration of FAE increased grip strength, exercise performance, muscle mass, and volume in mice. FAE stimulated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, enhancing the mammalian target of rapamycin pathway for muscle synthesis. FAE phosphorylated Forkhead box O3 and downregulated muscle RING finger-1 and atrogin-1 for proteolysis. FAE inhibited the mRNA expression of tumor necrosis factor alpha and interleukin-6 through nuclear factor kappa B. Consequently, FAE attenuated muscle atrophy by regulating the PI3K/Akt pathway and inflammation.