P 179 - Antioxidant activity and intestinal absorption of apigenin and its potassium salt derivative in Caco-2 cell monolayers

Abstract

Apigenin is a common bioactive flavonoid found in a variety of fruits, plants and vegetables. Many pharmacological activities of apigenin have been identified, but its low water solubility limits clinical evidence on its oral bioavailability. This study estimated the antioxidant activity of apigenin and its potassium salt derivative (apigenin-K) and the intestinal permeability of both compounds in Caco-2 cell monolayers. The antioxidant activity was evaluated with different methods: trolox equivalent antioxidant capacity (TEAC) and ferric reducing-antioxidant power (FRAP). Intestinal permeability coefficient was estimated in Caco-2 cell monolayer model with the addition of apigenin or apigenin-K to the apical (AP) or basolateral (BL) site. Apigenin exhibited a higher antioxidant activity than apigenin-K. Intestinal absorption evaluation corroborated the low permeability of both apigenin and apigenin-K. These results indicate that apigenin and apigenin-K may be considered as antioxidant ingredients for oral administration. Their low absorption estimation suggests that encapsulation may be necessary to enhance apigenin bioavailability for oral applications.