Setaria viridis Ethanol Extract Attenuates Muscle Loss and Body Fat Reduction in Sarcopenic Obesity by Regulating AMPK in High-Fat Diet-Induced Obese Mice.

Abstract

Sarcopenic obesity, characterized by the concurrent presence of sarcopenia and obesity, presents a complex challenge due to the synergistic detrimental effects of muscle loss and excess body fat. This study investigated the potential of Setaria viridis (SV) supplementation for mitigating the impact of sarcopenic obesity on diet-induced obese mice. Mice in the study were divided into groups and fed a normal diet, a high-fat diet (HFD), or an HFD supplemented with 0.3% SV ethanol extract. After 16 weeks, SV supplementation significantly reduced body weight gain and white adipose tissue mass, improved plasma lipid profiles, and preserved liver function without affecting food intake. Additionally, SV enhanced skeletal muscle mass and hind-limb thickness, and restored anabolic signaling pathways such as IGF-1, PI3K/Akt, and mTOR. Notably, SV supplementation activated AMP-activated protein kinase (AMPK), accompanied by increased expression of SIRT1 and PGC-1α, leading to improved mitochondrial function and reduced intramuscular fat deposition. Mechanistically, 3D molecular docking simulations revealed that luteolin 7-O-glucoside, a SV-derived flavonoid, binds to the AMPK ATP-binding site with high affinity, providing structural insight into SV's AMPK-activating potential. Furthermore, SV reduced levels of pro-inflammatory cytokines (TNF-α, IL-6) and enhanced antioxidant enzyme activity (GSH, GR, GPx), thereby alleviating oxidative stress and tissue fibrosis. These findings suggest that SV supplementation counters obesity-induced muscle atrophy and metabolic dysfunction through flavonoid-mediated AMPK activation, supporting its potential as a safe and effective nutritional strategy for managing sarcopenic obesity.