*4.7. Evaluation of Glucose Transport in Caco-2 Cells*

Glucose transport was evaluated in differentiated Caco-2 cells as described by Sharma et al. (2020) [12], applying some modifications. The transport was analyzed both in a sodium and non-sodium environment. Caco-2 cells were washed 2 times in HBBS (pH 7.5). Subsequently, POE (15 μg/mL) was co-incubated for 24 h in the apical compartment with 5 mM D-glucose prepared in DPBS. In the basolateral compartment was added DPBS. Similarly, sodium-free buffer was used for the sodium independent absorption experiment. Cells were incubated at 37 ◦C and 5% CO2 for the duration of the experiment. To follow transport across the cell monolayer, 50 μL was collected in the basolateral compartment at time 0 and after 24 h. Glucose transport was measured using 65.8 mM of *p*-hydroxyacetophenonebenzoylhydrazone (PAHBH) added to the collected samples (30:1). The mixture was incubated for 10 min at 90 ◦C and then read in a 96-well plate reader at 410 nm. Glucose (0.01–5 mM) was used to create the standard curve. Data were expressed as % of glucose transport with respect to each specific control [38].
