Fig. 5

Effect of piperine on TNF-α-induced intestinal barrier defects in 2D porcine duodenal enteroid monolayer. Cells were treated with 50 ng/mL TNF-α with or without 8 or 20 μg/mL piperine for 24 hours. a For FITC-dextran experiment, cells were then treated with 15 μL 4 kDa FITC-dextran for 1 hour. Basolateral medium was collected. The concentration of FITC-dextran in the cell culture medium at the basolateral side was calculated according to standard curve of FITC-dextran. (n = 3) (**: p-value < 0.01 compared with vehicle, #: p-value < 0.05 compared with 50 ng/mL TNF-α). b For ZO-1 localization, cells were stained with rabbit ZO-1 antibody, following with Alexa Fluor 488 anti-rabbit IgG and Hoechst as nuclear staining. Red arrowheads indicate a linear form of ZO-1 localization