Black ginger (Kaempferia parviflora) extract ameliorates high-fat diet-induced muscle atrophy through regulation of protein homeostasis and mitochondrial biogenesis.

This study investigated the inhibitory effects of a standardized Kaempferia parviflora ethanol extract (KPE) on muscle atrophy in high-fat diet (HFD)-induced obese mice. We hypothesized that KPE would ameliorate HFD-induced muscle atrophy in association with changes in muscle protein homeostasis and mitochondrial biogenesis. To test this, male C57BL/6J mice were fed an HFD for 6 weeks to induce obesity and skeletal muscle atrophy, followed by oral administration of KPE (100 or 200 mg/kg/d) for 8 weeks. KPE significantly attenuated HFD-induced muscle atrophy by increasing muscle mass, muscle strength, and exercise capacity. In the gastrocnemius muscle, KPE reduced the expression of pro-inflammatory cytokine genes and suppressed muscle protein degradation by inhibiting the expression of E3 ubiquitin ligases and autophagy-related genes. In addition, KPE enhanced mitochondrial biogenesis-related gene expression and muscle protein synthesis, accompanied by modulation of the phosphoinositide 3-kinase/protein kinase B/mechanistic target of rapamycin signaling pathway. These findings suggest that KPE alleviates muscle atrophy in HFD-induced C57BL/6J obese mice by inhibiting pro-inflammatory cytokines and muscle protein degradation while stimulating mitochondrial biogenesis and muscle protein synthesis.