Anti-inflammatory effects of citrus essential oils metabolites in the gut.

Citrus essential oil (CEO) is a natural extract from citrus fresh peel. It shows multiple biological activities such as anti-inflammatory effect after oral administration. However, CEO is rapidly absorbed in the small intestine and undergoes metabolization in the liver. It may also irritate the mucous layer of the gastrointestinal tract. Encapsulation within indigestible protein particles holds premises to prevent CEO absorption in the small intestine and delivery into the large intestine, where CEO can execute anti-inflammatory effects. Colon delivery may also enable targeting of malignant cells for treatment of patients with certain types of cancer. Zein is a prolamin protein and has been widely used in delivery of bioactive compounds, which is an ideal carrier for CEO. We expect to develop a colon-specific CEO-loaded capsules and mechanistically explain its anti-inflammatory functionality.