Fruit of Schisandra chinensis and its bioactive component schizandrin B ameliorate obesity-induced skeletal muscle atrophy.

[Display omitted] • OM increased skeletal muscle weight and improved muscle function in obese mice. • OM upregulated AKT/mTOR pathway and downregulated Smad-FOXO signaling. • Schizandrin B, a major bioactive compoenet of OM, downregulated Smad-FOXO signaling in palmitic acid-treated C2C12 cells. • These results suggest the OM ameliorated obesity-induced skeletal muscle atrophy in mice. Schisandra chinensis fruit (Omiza in Korean), used for the production tea or liquor, and is known to enhance skeletal muscle function. However, the effect of Omiza extract (OM) on obesity-induced skeletal muscle atrophy remains unclear. This study investigated the effect of OM on skeletal muscle mass and performance in obese mice. OM increased skeletal muscle weight, size and improved skeletal muscle performance. Further, it also suppressed obesity-induced increases in proinflammatory cytokines, MuRF1, and Atrogin1 in mouse skeletal muscle and enhanced the expression of MHC and the phosphorylation of AKT/mTOR signaling molecules, thereby suppressing myostatin expression and regulating Smad-FOXO signaling. Schizandrin B, a major component of OM inhibited palmitic acid induced atrophy in C2C12 cells via Smad-FOXO regulation, suggesting that it partially contributed to the effects of OM against obesity-induced muscle atrophy. Taken together, OM may have the potential to prevent and treat obesity-induced muscle atrophy. [ABSTRACT FROM AUTHOR]