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

To investigate the effects of Quercetin on vocal fold fibroblasts induced by TGF-β1 and vocal fold injury.

The effects of Quercetin on collagen type I (COL-I), collagen type III (COL-III), and fibronectin (FN) expressions in transforming growth factor-β1 (TGF-β1)-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.

Compared with cells untreated with TGF-β1, the mRNA and protein expression levels of COL-I, COL-II, and FN and proliferation ability in TGF-β1-induced human vocal fold fibroblasts were increased (all P<0.05). Compared with human vocal fold fibroblasts induced by TGF-β1, the mRNA and protein expression levels of COL-I, COL-II, and FN and proliferation ability in TGF-β1-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).

Quercetin inhibited TGF-β1-induced fibrotic changes and proliferation in human vocal fold fibroblasts and had an antifibrotic effect in vocal fold after injuries.