QXT extraction attenuated ROS-mediated E-cadherin downregulation in human lung epithelial cells. (A–C) Cultured 16HBE cells were incubated with H2O2 (40 μM) for different times. The expression level of E-cadherin was determined via qPCR (n=3, A) and Western blotting (n=3, B, C). (D–L) Cultured 16HBE cells were incubated with H2O2 or treated with H2O2 (40 μM) plus the water or ethanol extract from QXT (80 μg/mL) for 48 h or 72 h. The expression level of E-cadherin was determined via qPCR (n=3, D), Western blotting (n=3, E, F), and immunofluorescence (n=3, G, H). ROS level was determined via DCFH-DA and observed with a fluorescence microscope (n=3, I, J). The levels of SOD and TAOC were detected by colorimetry (n=3, K, L). The protein levels of E-cadherin were quantified by using Image J software and normalized to β-actin. Data are shown as the mean±standard, * P<0.05, ** P<0.01.