Gastrointestinal in vitro digestion and inmunoregulatory effect of pomegranate oil extracted by clean technologies in Caco-2 cells

Abstract

Pomegranate seeds contain up to 20% oil with a high content of punicic acid (85%), which is responsible of several bioactive activities in human health. In this work, pomegranate oils extracted by pressing (PP) and supercritical CO2 (PSCF), have been studied in a static gastrointestinal in vitro digestion model to evaluate their digestibility and bioaccessibility. The micellar phases obtained were evaluated by an in vitro model of intestinal inflammation and Caco-2 cells exposed to the inflammatory mediator LPS. Inflammatory response was assessed by measuring the production of IL-6, IL-8 and TNF-α, and by evaluating the monolayer permeability. The results obtained indicate that PP extraction provides the highest amount of micellar phase (ca. 93%) with free fatty acids and monoacylglycerols as major components. The micellar phase obtained under PSFC extraction is ca. 82% with the same species composition. PP extracted oil shows an anti-inflammatory response, reducing the production of IL-8, IL-6 and TNF-α, and increasing TEER values in comparison with LPS stimulated cells. In the case of PSCF extraction, the reducing response of inflammation happens only for IL-8. The present work demonstrates the good digestibility, bioaccessibility and immunoregulatory response of both pomegranate oils, especially that obtained by PP extraction.