Abstract: Identification of active molecules with gastrointestinal anti-inflammatory properties mostly relies on time-consuming methods that quantify the effect of these compounds on the expression and/or release of cytokines (e.g., IL-8). To speed up this process, ReadyCell offers a rapid detection approach based on the correlation between gut inflammation and intestinal barrier dysfunction. To this end, CacoGoblet, a 21-day differentiated co-culture of Caco-2 and HT-29 cells in 24 insert-permeable supports, were preincubated or not with baicalein, a molecule with recognized anti-inflammatory activity at concentrations ranging from 25 µM to 200 µM. At the end of exposure, cells were induced with a cocktail of cytokines (IL-1β, TNF-α, and INF-ϒ) and lipopolysaccharide (LPS) in the absence or presence of the anti-inflammatory compound for up to a 72-hour period. Membrane integrity was characterized by measuring the transepithelial electrical resistance (TEER) and the Lucifer Yellow Paracellular Permeability (LY-Papp) after 24, 48 and 72 hours of incubation. As expected, the evaluation of TEER and LY-Papp in cytokine-induced cells non-exposed to baicalein decreased TEER values by 35 % and increased LY-Papp by 50% after 72 hours of exposure. Even more, TEER values and LY-Papp correlated in the inflammatory state with a 45-fold release of IL-8 compared to the non-induced cells. On the contrary, cytokine-induced cells in the presence of the anti-inflammatory compound normalized cell barrier integrity and IL-8 release to the basal level in a dose-dependent manner. This study indicates that CacoGoblet and the two selected parameters (TEER and LY-Papp) are compliant and useful in vitro tools for screening compounds with anti-inflammatory activity at the early stages of drug development. They offer simplicity and high reproducibility between assays.
