Regulatory Effects of Quercetin on Extracellular Matrix in Injured Vocal Folds.

To investigate the regulatory effect of quercetin (QUE) on extracellular matrix (ECM) in injured vocal folds using a Sprague Dawley (SD) rat model of vocal fold scarring. Thirty-six SD rats were randomly divided into four groups: normal control group (NC), vocal fold injury group (VFI), low-dose quercetin (QUEL, 100 mg/kg), and high-dose quercetin (QUEH, 200 mg/kg). Using Alcian Blue staining, modified Elastica van Gieson (EVG) staining, Western Blot (WB), and gray-level co-occurrence matrix (GLCM), the study evaluated changes in the content and arrangement of ECM components, including hyaluronic acid (HA), elastic fibers (EF), type I collagen fibers (COL1A1), and fibronectin-1 (FN1). Compared with NC, vocal fold injury reduced HA/EF and increased COL1A1/FN1 in lamina propria (all P < 0.05). Quercetin treatment (QUEL/QUEH) significantly inhibited HA/EF loss (positive area: QUEL 19.88% ± 2.14% vs QUEH 24.72% ± 3.01% for HA; QUEL 0.71% ± 0.06% vs. QUEH 0.86% ± 0.05% for EF, P < 0.05) and decreased COL1A1/FN1 overexpression (28%-51% reduction vs. VFI, P < 0.05). Texture analysis showed QUE increased energy (0.39 ± 0.10 in QUEH vs 0.27 ± 0.10 in VFI) and decreased entropy (1.12 ± 0.16 vs 1.79 ± 0.34, P < 0.0001), indicating improved ECM order in a dose-dependent manner. QUE suppressed the depletion of HA and EF in the lamina propria of injured vocal folds, attenuated the overexpression of COL1A1 and FN1, and ameliorated the disordered organization of the ECM.