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

Figure 8 The effect of berberine on cytokine- and peroxide-induced leak of CACO-2 cell layers. A: After electrical measurements, the same CACO-2 cell layers represented in B were used to perform radiotracer flux studies with 0.1 mmol/L, 0.025 μCi/mL ¹⁴C-PEG. Data represent the percent of control flux rate, and is expressed as the mean ± SE of 4 cell layers per condition (3 cell layers for the condition of cytomix + peroxide, due to removal of one outlier data point, as determined by a 90% confidence level in the Dixon’s Q test); B: Seven-day post-confluent CACO-2 cell layers on Millipore polycarbonate filters were refed in control medium or medium containing 100 μmol/L berberine. After 24 h treatment with berberine alone, the cell layers were given either control or berberine medium, in addition to being exposed to either cytomix (50 ng/mL tumor necrosis factor-α, 100 ng/mL interferon-γ, 50 ng/mL interleukin-1β) or no cytokines (apical and basal-lateral compartments) for 48 h. On the day of the experiment, the cell layers were treated for 5 h with control saline or saline containing 1 mmol/L hydrogen peroxide ± berberine. Data shown represent the mean ± SE of 4 cell layers per condition, with data expressed as the percent of control resistance. ^bP < 0.01 vs cytomix + H₂O₂; ^dP < 0.001 vs H₂O₂ alone (one-way ANOVA followed by Tukey’s post hoc testing). Experiment was repeated with similar results.