Figure 4.

The qRT-PCR: Normalized fold expression of different tight junction protein mRNA after 4 h incubation with 400 µM quercetin. The qRT-PCR revealed an increased mRNA level of claudin 4 in the VE to 1.70 (±0.26, n = 4). No effect on the other tight junction proteins could be detected. In PPs, none of the tight junction proteins were influenced by quercetin (n = 4). The dashed line indicates the controls. Values are given as mean ± SEM and asterisks indicate significant differences, * = p ≤ 0.05.