Original Antifibrotic effects of Quercetin on TGF-β1-induced vocal fold fibroblasts

Objective: To investigate the effects of Quercetin on vocal fold fibroblasts induced by TGF-131 and vocal fold injury. Methods: The effects of Quercetin on collagen type I (COL-I), collagen type III (COL-III), and fibronectin (FN) expressions in transforming growth factor-131 (TGF-131)-induced human vocal fold fibroblasts were examined by the quantitative reverse transcription-polymerase chain reaction and the enzyme-linked immunosorbent assay. The Cell Counting Kit-8 was used to assess the influence of Quercetin on cell proliferation. A rat vocal fold injury model was developed. These rats were divided into a control group, a model group, and a Quercetin group. Pathorphological observations from Hematoxylin-eosin staining, the density of fibroblasts, and hypertrophic index were compared among the three groups. Results: Compared with cells untreated with TGF-131, the mRNA and protein expression levels of COL-I, COL-II, and FN and proliferation ability in TGF-131-induced human vocal fold fibroblasts were increased (all P < 0.05). Compared with human vocal fold fibroblasts induced by TGF-131, the mRNA and protein expression levels of COL-I, COL-II, and FN and proliferation ability in TGF-131-induced human vocal fold fibroblasts following Quercetin stimulation were decreased (all P < 0.05). There were no statistical differences between human vocal fold fibroblasts treated with or without Quercetin regarding cell proliferation and COL-I, COL-II, and FN expressions. Compared with the model group, Quercetin suppressed the fibrosis of the vocal fold following injury and the protein levels of COL-I, COL-II, and FN in tissue samples (all P < 0.001). The density of fibroblasts and hypertrophic index in the vocal fold scar from the Quercetin group were lower than those in the model group (all P < 0.05). Conclusions: Quercetin inhibited TGF-131-induced fibrotic changes and proliferation in human vocal fold fibroblasts and had an antifibrotic effect in vocal fold after injuries.

Automated summary

Quercetin inhibits proliferation and fibrotic changes in vocal fold fibroblasts, and has an anti-fibrotic effect after vocal fold injuries.