Figure 4.

Cell viability assay and measurement of TEER under different experimental conditions. Caco-2 cells, cultured on Transwell inserts for 21 days were exposed to pro-inflammatory cytokines (TNFα 10 ng/mL + IL-1β 5 ng/ml) for 24 h after a 24 h pre-treatment with two different concentrations in polyphenols of digested cinnamon extract (23 and 46 µg/mL). Then, a MTT assay was performed, and results are reported in the histograms. Single conditions were also tested. Data are expressed as a percentage against the untreated cell line used as a control and are shown as mean ± SE from three independent experiments (A). TEER measures (Ώ·cm²) were performed before (0 h) and after (24 h) cytokines treatment (B). The ΔTEER of cells exposed to cytokines was calculated and reported in the histograms as number (left Y-axes) and percentage (right Y-axes). Data represent the mean ± SEM from at least three independent experiments (C). Statistical significance: *** p < 0.001 vs. untreated cells, ### p < 0.001 vs. TNFα/IL-1β.