Yansong Fu, Xin Zeng, Bin Zhou, Jiayun Wang, Hong Qin
Background/Objectives: In obese skeletal muscle, impaired insulin signalling and persistent low-grade inflammation frequently arise together, jointly driving metabolic dysfunction; yet a single intracellular node capable of simultaneously correcting both defects has not been identified. Curcumol is the principal active sesquiterpene of the traditional Chinese herb Curcuma zedoaria (Christm.) Rosc. We therefore sought to determine whether curcumol modulates obesity-driven insulin resistance and inflammatory activation in skeletal muscle, and to delineate the responsible molecular pathway. Methods: The study combined in vivo and in vitro experiments with network pharmacology, molecular docking, pharmacological inhibition, and cellular thermal shift assay (CETSA). In vivo experiments used mice rendered obese by prolonged high-fat diet (HFD) feeding; in vitro, insulin resistance was modelled in C2C12 myotubes via palmitate challenge. Network pharmacology implicated SRC as a principal candidate target, and molecular docking assigned SRC kinase the highest binding affinity for curcumol. Selective blockade of SRC (PP2) and PI3K (LY294002) was used to delineate the signalling hierarchy. Results: Network pharmacology and molecular docking identified SRC kinase as the highest-ranked candidate target of curcumol. In both HFD-induced obese mice and palmitate-challenged C2C12 myotubes, curcumol restored SRC phosphorylation and activated the downstream PI3K/AKT axis, concurrently improving insulin sensitivity and attenuating NF-kB-driven inflammatory responses. Selective PI3K inhibition abolished all functional benefits of curcumol without altering SRC phosphorylation, whereas SRC blockade with PP2 prevented both PI3K/AKT activation and the downstream recovery of insulin sensitivity and inflammatory suppression, placing SRC upstream of PI3K/AKT in the signalling order. Direct binding of curcumol to SRC protein was confirmed by a cellular thermal shift assay. Conclusions: Curcumol directly engages SRC kinase and, through subsequent PI3K/AKT axis activation, concurrently rescues skeletal muscle insulin sensitivity and suppresses metabolic inflammation. These findings provide mechanistic justification for developing curcumol as a candidate dietary bioactive compound toward preventing and treating obesity-related metabolic disturbances.