Oleoylethanolamide attenuates early skeletal muscle metabolic remodeling induced by short-term high-fat diet exposure

Obesity develops through progressive metabolic alterations that arise long before overt disease, highlighting the need for pharmacological strategies capable of targeting the earliest tissue adaptations to fat nutrient excess. Skeletal muscle plays a central role in systemic metabolic homeostasis and is among the first organs affected by high-fat diet (HFD) exposure. Oleoylethanolamide (OEA), a peroxisome proliferator-activated receptor alpha (PPAR-α) agonist, exerts broad metabolic actions in obesity, yet its impact on early skeletal muscle remodeling remains unknown. We investigated whether OEA could intercept the initial metabolic adaptations induced by HFD exposure in young rats. Male rats were exposed to HFD for seven weeks and treated with OEA (10mg/kg, i.p.) during the final two weeks. Short-term HFD induced a coordinated remodeling of skeletal muscle characterized by lipid accumulation, suppression of the PPAR-α/CPT-1 axis, altered mitochondrial and redox homeostasis, extracellular matrix remodeling, impaired myogenic signaling, and a shift toward a glycolytic contractile program despite only modest body-weight gain. OEA largely attenuated such alterations, preserving skeletal muscle metabolic and structural homeostasis through coordinated improvement of lipid oxidative metabolism, mitochondrial energetic status, and tissue remodeling. These findings identify skeletal muscle as an early target of fat-induced metabolic dysfunction and support further investigation of OEA as a promising pharmacological strategy to intercept obesity-associated metabolic deterioration before overt obesity develops.