Evodiamine may inhibit insulin resistance in type 2 diabetes through IRS-1/PI3K/AKT/GLUT4 pathway

This research aimed to elucidate the potential therapeutic efficacy of evodiamine (Evo) in alleviating IR associated with T2DM, and to further explain its underlying mechanism. The candidate bioactive components and targets of EVO were identified by using biomedical databases. Targets associated with IR were acquired from various databases. Intersectional analysis of Evo-related and IR-specific targets facilitated the construction of a PPI network. Cytoscape software was employed for the visualization of the "compound-target-disease" interactions, enabling the identification of key proteins. GO and KEGG analyses were then carried out to clarify the biological roles of the core Evo targets. MD analysis further confirmed the interactions between Evo and these key proteins. Additionally, the CCK-8 assay evaluated the influence of Evo on cell viability. The effects of Evo on glucose uptake and release were quantified, while Western blotting (WB) was employed to identify changes in protein expression driving the IRS-1/PI3K/AKT/GLUT4 signaling pathway. Furthermore, immunofluorescence techniques were implemented to visualize and quantify the expression levels of IRS-1, phosphorylated IRS-1 (p-IRS-1), and GLUT4 in insulin-resistant HepG2 cells. A total of 122 Evo-associated targets were obtained, among which 37 intersected with IR-related targets. Notably, AKT1, STAT3, SRC, and PTGS2 were identified as crucial proteins within this network. KEGG pathway analysis revealed enrichment of 126 significant pathways, among which the PI3K/AKT signaling pathway was particularly critical in mediating the therapeutic effects of Evo on IR. HepG2 cells in the model group showed lower glucose consumption and higher glucose production than controls, whereas Evo administration enhanced glucose consumption and reduced glucose production. Using metformin as a positive control, statistically significant differences in glucose consumption and production were found between HepG2 cells treated with Evo and metformin. Additionally, the model group exhibited significantly lower p-AKT and p-PI3K expression versus controls. In IR-HepG2 cells, Evo treatment dose-dependently restored diminished p-AKT and p-PI3K levels, mirroring metformin's action. Relative to controls, the model group exhibited elevated p-IRS-1, which was downregulated by Evo in IR-HepG2 cells; metformin, however, failed to reduce p-IRS-1 significantly. The results of our study indicate that Evo's ability to function as a therapy for IR might be linked to its role in modulating the IRS-1/PI3K/AKT signaling pathway and increasing the GLUT4 expression.