Background
Drugs and diet interact with each other in mutually influencing their bioavailability. In our previous work we have shown that N-acetyl-p-aminophenol (APAP, acetaminophen) reduces the paracellular transport activities of itself and co-administered substances. The aim of this study was to find out how APAP reduces the bioavailability of small molecules which pass paracellularly, and which tight junction proteins are involved in the regulation of paracellular transport using a Caco-2 barrier model.