In vitro Anti-inflammatory and Protective Effects of ibidì® on Intestinal Epithelial Cells

Abstract

Aim: To define the putative anti-inflammatory and cytotoxic effects of ibidì®, a new phytotherapeutic formulation composed of three extracts: Punica granatum L, pericarpum; Boswellia serrata Roxb., resina; Curcuma longa L,. rhizome, using Caco-2 cells, an in vitro model of human intestinal epithelium. Methodology: cytotoxicity and capacity of ibidì® to induce cell proliferation were assessed respectively by 2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide (XTT) assay and nucleotide 5-bromo-2’-deoxyuridine (BrdU) incorporation. Cell migration was evaluated by scratch wound assay. COX-2, IL-6, IL-8 and MCP-1 protein levels were measured in the supernatant of cells stimulated with or without TNF-alfa or IL-1 beta in presence or in absence of ibidì® using ELISA assays. Finally, the influence of ibidì® on the integrity, paracellular permeability, and viability of Caco-2 cell monolayers was monitored by measuring the transepithelial electrical resistance (TEER) in presence or in absence of TNF-a stimulation. Results: No dose-response toxicity was observed after 48 h incubation with ibidì®. Interestingly the cell proliferation rate was generally lower in presence of ibidì® than vehicle at all concentrations tested, while ibidì® had no effects on cell migration. Ibidì® markedly inhibited TNF-alfa-induced production of IL-8 at all concentrations tested in a dose-response manner, while that of IL-6 and MCP-1 only at highest ibidì® concentrations. Importantly ibidì® in a range of concentration between 145 and 9 µg/ml not only abrogated TNF-alfa-dependent TEER depression, but also promoted higher resistance values than untreated cells. Conclusion: These data demonstrate that ibidì® exerts anti-inflammatory and protective effects on intestinal epithelial cells by blocking the production of IL-8, IL-6 and MCP-1, and unveil that the synergism of the three extracts regulates epithelial barrier function.