Figure 3.

(A) Effect of leek extract on the response of epithelial cells to oxidative stress. On day 7, ALI-cultured Calu-3 cells were grown in the presence or absence of leek extract (LE, 5 μg/mL) for 48 h and then exposed to 1 mM H₂O₂. The time course of transepithelial electrical resistance (TEER) was measured. PBS, control cells. * p < 0.05 mRNA levels of GST (B), c-Jun (C) and NFκB (D) in ALI-cultured Calu-3 cells exposed to 1mM H₂O₂ for 48 h, after treatment with leek extract (5 μg/mL, LE) compared to control cells (PBS). Relative mRNA levels were determined by RT–PCR and expressed as fold increase of control values after normalization using GADPH as the housekeeping gene. Data are mean ± SEM of three different experiments. * p < 0.05, ** p < 0.01, **** p < 0.0001.