Figure 4.

Pretreatment with piperine attenuates TGF-β1-induced mesenchymal-like phenotype in A549 cells. A549 cells were pretreated with non-cytotoxic doses of piperine (20, 40 and 80 μM) for 24 h, followed by treatment with 1 ng/mL TGF-β1 for 48 h. After treatment, cells were used for Western blot and qPCR analysis. (A) Western blot analysis of the expression of mesenchymal markers fibronectin (B) and N-cad (C). GAPDH was used as loading control. Densitometry was performed using the image-processing program ImageJ. The relative copy number of transcripts for fibronectin (D), N-cad (E) and E-cad (F) was determined by qRT-PCR to evaluate changes in gene expression. The results are representative of three independent experiments. The results are shown as mean ± SD. * p ≤ 0.05 vs. untreated cells (CTR); † p ≤ 0.05 vs. TGF-β.