An Ethanol Extract of Artemisia iwayomogi Activates PPARδ Leading to Activation of Fatty Acid Oxidation in Skeletal Muscle

Although Artemisia iwayomogi (AI) has been shown to improve the lipid metabolism, its mode of action is poorly understood. In this study, a 95% ethanol extract of AI (95EEAI) was identified as a potent ligand of peroxisome proliferator-activated receptorδ (PPARδ) using ligand binding analysis and cell-based reporter assay. In cultured primary human skeletal muscle cells, treatment of 95EEAI increased expression of two important PPARδ-regulated genes, carnitine palmitoyl-transferase-1 (CPT1) and pyruvate dehydrogenase kinase isozyme 4 (PDK4), and several genes acting in lipid efflux and energy expenditure. Furthermore, 95EEAI stimulated fatty acid oxidation in a PPARδ-dependent manner. High-fat diet-induced obese mice model further indicated that administration of 95EEAI attenuated diet-induced obesity through the activation of fatty acid oxidation in skeletal muscle. These results suggest that a 95% ethanol extract of AI may have a role as a new functional food material for the prevention and/or treatment of hyperlipidermia and obesity.