TY - JOUR TI - Assessing the in vitro bioavailability of tangeretin and its derivatives in Caco-2 cell model DO - https://doi.org/doi:10.7282/T3PN97BN PY - 2015 AB - Flavonoids are widely distributed in fruits, vegetables and grains. Tangeretin (TAN) is one of the most abundant polymethoxyflavones (PMFs), which is found almost exclusively in citrus peel. In present work, we applied silica gel column chromatography to purify tangeretin from bitter orange citrus peel extracts mixture. Despite of the wide bioactivities documented, tangeretin has relatively low bioavailability due to its low water solubility, which is a major limiting their application as functional neutraceuticals. Therefore, hydroxylation and acetylation reaction was carried out to improve the solubility of TAN. Moreover, the bioactivity and bioavailability of TAN, 5-OH-TAN and 5-Ac-TAN were evaluated using cell viability assay and transport assay on Caco-2 human colon carcinoma cell line. When compared to TAN, stronger anti-proliferation activities were stronger in 5-OH-TAN and 5-Ac-TAN among which 5-Ac-TAN showed the strongest inhibition. The Caco-2 monolayer transport assays were in good agreement that 5-Ac-TAN had better ability to across through cell membranes. Interestingly, 5-OH-TAN and 5-Ac-TAN were subjected to cellular transformation when passing through the cellular membrane. While 5-OH-TAN was partially methylated to TAN, 5-Ac-TAN was transformed into both TAN and 5-OH-TAN, which in total was transported in higher concentration from apical compartment to basolateral side than 5-OH-TAN group. In summery, 5-Ac-TAN had the strongest bioactivity of inhibiting the growth of Caco-2 colon carcinoma cells than TAN and 5-OH-TAN. In addition, 5-Ac-TAN also higher membrane permeability than 5-OH-TAN in Caco-2 monolayer cells. Therefore, functional group on C5 position seems to have critical effect on the compounds’ biological abilities as well as the bioavailability. KW - Food Science KW - Flavonoids--Physiological effect KW - Citrus KW - Cancer cells LA - eng ER -