NRF2 Activation Inhibits Both TGF-β1- and IL-13-Mediated Periostin Expression in Fibroblasts: Benefit of Cinnamaldehyde for Antifibrotic Treatment

Figure 2

Effects of cinnamaldehyde on TGF-β1- and IL-13-induced expression of periostin mRNA and protein in dermal fibroblasts. (a) NHDFs were stimulated with 20 ng/mL TGF-β1 or 50 ng/mL IL-13 or unstimulated (control) for 20 min. Cells were incubated with carboxy-H₂DCFDA for 25 min, after which ROS production was visualized by fluorescence microscopy. Scale bars, 200 μm. (b, c) Effects of cinnamaldehyde (CIN) on TGF-β1-induced expression levels of periostin (POSTN) mRNA and protein. (d, e) Effects of CIN on IL-13-induced expression of POSTN mRNA and protein. NHDF cells were precultured with the indicated concentration of CIN for 30 min and then treated with 5 ng/mL TGF-β1 or IL-13 or left untreated for 48 h. Expression levels of POSTN mRNA and protein in the cell supernatants are depicted. The values were adjusted by GAPDH expression. The same experiments were performed three times. , . NS: not significant.

(a)

(b)

(c)

(d)

(e)