35 The epithelial barrier damaging effects of commonly used food emulsifiers P80 and P20 on Caco-2 gastrointestinal epithelial cells
Background: Emulsifiers are a class of food additives used in food processing to alter the flavor, improve the texture, stability and shelf-life of foods. Their structures contain both hydrophobic and hydrophilic moieties that allow them to exist in both water and lipid fractions, thereby creating a consistent, homogenous mixture of immiscible liquids. Polysorbate 80 (P80), also known commercially as Tween 80 is derived from dehydrated sorbitol (sorbitan) and oleic acid. Polysorbate 20 (P20, Tween 20) is formed by the ethoxylation of sorbitan before the addition of lauric acid. They are found in a large number of food products including baked food, milk and cream analogs, edible ices, desserts, sugar confectionary, emulsified sauces and soups.
Objective: We investigated the effects of P20 and P80 on cytotoxicity and barrier function of gastrointestinal epithelial cells.
Methods: Cytotoxicity was evaluated by fluoremetric lactate dehydrogenase release. Enterocytic monolayers were established by culturing Caco-2 cells on permeable supports that separate the apical and basal compartments. P20 and P80 were added to the apical compartment, and then the transepithelial electirical resistance (TER) was measured at 0, 24, 48, and 72 hours. Paracellular FITC-Dextran flux measurements were performed by fluorometry.
Results: P80 and P20 showed dose-dependent cellular toxicity on Caco-2 cells after 24 and 72 hours of exposure. P80 at 0.05% and P20 at 0.025% vol/vol concentrations resulted in the decrease of the viability in Caco-2 cells. There was no toxicity of P80 and P20 at the lower concentrations of 0.005-0.025% and 0.0005-0.01%, respectively. We did not observe any disruption of the monolayer integrity, as indicated through maintenance of TER with P80 concentration of £0.5%, whereas P80 and P20 concentrations of ³1% induced a dramatical decrease in TER. A disrupted epithelial barrier function was found with increased paracellular flux in Caco-2 cells exposed to P80 at 0.01% and 0.005% amounts.
Conclusion: Our data demonstrated that P80 and P20 show cell toxicity and epithelial barrier integrity damaging effects on Caco-2 cells and particularly P80 was more potent at doses of daily usage.