*4.9. Chronic High Glucose Caco-2 Cell Treatment*

The chronic high glucose (HG) treatment of Caco-2 cells was carried out as previously described [20]. Briefly, cells were grown in 50 mM glucose for 1 week (high glucose, HG cells). Cells grown in growth medium without addition of glucose were used as control cells (Control cells). Medium was replaced two times a week. POE (15 μg GAE/mL) or *N*-acetyl-cysteine (NAC; 50 μM) was added to the media and co-incubated (in both HG and Control conditions) for the last 24 h.
