Quercetin Attenuates Vocal Fold Fibrosis via PI3K/AKT and MAPK Pathways: An Integrative Network Pharmacology and Experimental Study.

OBJECTIVE: This study combined network pharmacology with in vivo and in vitro experiments to investigate the molecular mechanisms of quercetin against vocal fold fibrosis (VFI). METHODS: Common targets of quercetin and VFI were identified via network pharmacology. A protein-protein interaction network was constructed, and key pathways were analyzed. Molecular docking was performed to evaluate binding affinity between quercetin and core targets. A rat model of vocal fold scar (in vivo) and TGF-β1-stimulated vocal fold fibroblasts (in vitro) were used to assess the expression of PI3K/AKT and MAPK pathway proteins, as well as changes in cell proliferation, migration, and apoptosis. RESULTS: A total of 92 common targets were identified, with significant enrichment in the PI3K/AKT and MAPK pathways. Molecular docking showed binding energies < -5 kcal/mol for quercetin with PI3K, AKT1, and p38. In vivo, quercetin significantly inhibited the expression of PI3K, AKT, and p38 (P < 0.05). Moreover, quercetin and the PI3K inhibitor Alpelisib both significantly improved extracellular matrix organization, as evidenced by increased Energy, Correlation, and Homogeneity, and decreased Entropy and Contrast in gray-level co-occurrence matrix analysis (P < 0.05). Both treatments also restored hyaluronic acid and elastic fiber content in scarred vocal folds (P < 0.05). In vitro, quercetin suppressed the proliferation and migration of vocal fold fibroblasts (P < 0.05) and promoted apoptosis (P < 0.05). CONCLUSION: Quercetin exerts anti-fibrotic effects on vocal folds by multi-target inhibition of PI3K/AKT and MAPK signaling pathways, thereby modulating fibroblast behavior, preserving extracellular matrix integrity, and restoring key matrix components such as hyaluronic acid and elastic fibers.