Sieving characteristics of cytokine- and peroxide-induced epithelial barrier leak: Inhibition by berberine

Figure 1 The effect of tumor necrosis factor-α on CACO-2 transepithelial electrical resistance and transepithelial flux of ¹⁴C-D-mannitol. A: Seven-day post-confluent CACO-2 cell layers on Millipore polycarbonate filters were refed in control medium or medium containing 200 ng/mL tumor necrosis factor-α (TNF-α) (apical and basal-lateral compartments) 48 h prior to electrical measurements. Data shown represent the mean ± SE of 16 cell layers per condition. Data represent the percent of control resistance normalized across 3 experiments; B: After electrical measurements, radiotracer flux studies with 0.1 mmol/L, 0.1 μCi/mL 14C-D-mannitol were performed on CACO-2 cell layers, as described in Materials and Methods. Data represent the percent of control flux rate normalized across 4 experiments, and is expressed as the mean ± SE of 20 cell layers per condition. ^bP < 0.001 vs control (Student’s t test, one-tailed).