Plant-derived polyphenols and intestinal HT-29 cells: understanding the cellular uptake.

The polyphenols have aroused great scientific interest, since their beneficial effects are attributed to their antioxidant activity: the phenolic compounds can act as metal chelators, antimicrobial agents, radical scavengers, and might also trigger changes in cells and in the signaling pathways, as by preventing the LDL oxidation, platelet aggregation, and ROS generation. The health effects of polyphenols depend also on their bioavailability, which can vary greatly because of different factors, as the degree of hydroxylation, the molecular conformation, etc. A critical point in the debate on health effects of polyphenols is indeed their bioavailability, therefore we used the human colorectal carcinoma cells (HT-29), which are a reference model of intestinal cells, to evaluate the polyphenols ability to pass through the cellular membrane and permeate into the cell. The polyphenols studied in this research are from medicinal plants widely used in traditional medicine: baicalein (from Scutellaria baicalensis G.), eupatorin (Eupatorium semiserratum DC.), galangin (Alpinia officinarum L.), magnolol (Magnolia officinalis L.), myricetin (Myrica rubra S. Z.), oleuropein (Olea europaea L.) and silybin (Silybum marianum L.).