Yves-Jacques Schneider

Physio-pathological parameters affect the activation of inflammatory pathways by deoxynivalenol in Caco-2 cells

The intake of deoxynivalenol (DON), a mycotoxin contaminating cereal food items, causes gastro-intestinal illness in human and animal. This study investigated whether intracellular inflammatory cascades (MAPKs and NF-κB), cell maturity (proliferating vs. differentiated), cell state (control vs. inflamed) and exposure duration (chronic vs. acute) affect IL-8 secretion and PGE-2 synthesis in Caco-2 cells exposed to plausible intestinal concentrations (50, 500 and 5000 ng/ml) of DON. IL-8 secretion and PGE-2 synthesizing capacity were dose-dependently upregulated in differentiated Caco-2 cells exposed to DON during 24h, reaching an increase of ∼25 and 1.7-fold respectively, whereas transcript level of IL-8 and COX-2 were increased by ∼40 and 17-fold. Similar results were obtained with proliferating cells. The upregulation decreased upon simultaneous incubation with inhibitors of MAPKs ERK1/2 or p38 or of transcription factor NF-κB. IL-8 secretion and PGE-2 synthesizing capacity increased respectively by ∼15 and 2-fold after chronic 21 day incubation with DON (50 ng/ml). IL-8 production was exacerbated (∼510-fold versus negative control) upon simultaneous exposure to inflammatory stimuli. These results suggest activation of inflammatory pathways in intestinal epithelial cells exposed chronically or acutely to DON. The sensitivity to DON, whereas not affected by cell differentiation, is exacerbated by the presence of additional stimuli.

Food Nanoparticles and Intestinal Inflammation: A Real Risk?

Nanotechnology is a rapidly evolving field of research and industrial innovation with many potentially promising applications in agriculture, healthcare, engineering, processing, pack‐ aging or delivery of drugs or food supplements. Engineered nanomaterials (ENMs) already became part of our daily life as food packaging agents, drug delivery systems, therapeutics, biosensors, etc. In 2011, according to the Woodrow Wilson Nanotechnology Consumer Products Inventory, Ag nanoparticles (Ag-NPs) were the most commonly consumed ENMs, followed by TiO2, SiO2, ZnO, Au, Pt, etc (http://www.nanotechproject.org). By the most re‐ cent definition of European Parliament and Council [1] ‘nanomaterial’ (NM) is any material that is characterized to have at least one dimension ≤ 100 nm, or that comprises of separate functional parts either internal or on the surface, which have one or more dimensions ≤ 100 nm, including structures, e.g. agglomerates or aggregates, which may be larger than 100 nm, but which retain the typical properties of nanoscale.

The Use of Pomegranate (Punica granatum L.) Phenolic Compounds as Potential Natural Prevention Against IBDs

Phenolic compounds (PCs) are plant secondary metabolites that are integral part of the “normal” human diet. The daily intake of PCs depends on the diet but is commonly evaluated at ca. 1g/day for people who eat several fruits and vegetables per day (Scalbert & Williamson, 2000). PCs may be interesting to prevent the development of inflammatory diseases, more particularly in the gastrointestinal tract, where their concentration may reach levels of up to several hundred μM (Scalbert & Williamson, 2000). Many studies have indeed reported on anti-inflammatory properties of different PCs (see (Calixto et al., 2004; Rahman et al., 2006; Romier et al., 2009; Shapiro et al., 2009), for reviews). Pomegranate (Punica granatum L.) belongs to the Punicaceae family, which includes only two species. More than 500 cultivars of Punica granatum exist with specific characteristics such as fruit size, exocarp and aril color, etc. Originating from the Middle East, pomegranate is now widely cultivated throughout the world, and also widely consumed. Pomegranate has been used for centuries in the folk medicine of many cultures. As described in the review of Lansky et al. (2007), the bark and the roots are believed to have anthelmintic and vermifuge properties, the fruit peel has been used as a cure for diarrhea, oral aphthae, and as a powerful astringent, the juice as a blood tonic, and the flowers as a cure for diabetes mellitus. Numerous investigations have highlighted the anti-inflammatory potential of the PCs found in this fruit, and more especially of hydrolysable tannins called ellagitannins (ETs), which are mainly located in pomegranate peels. These ETs are extracted into the juice upon commercial processing of the whole fruit (Gil et al., 2000). This chapter first describes the PCs found in pomegranate fruit, then focuses on ETs in relation to their metabolic fate after ingestion as well as to their anti-inflammatory properties on the intestine, and finally discusses gut microflora modifications following pomegranate ingestion and their impact on intestinal inflammation.