Tissue deconjugation of urolithin A glucuronide to free urolithin A in systemic inflammation.

Urolithin A (Uro-A) is an anti-inflammatory and cancer chemopreventive metabolite produced by the gut microbiota from the polyphenol ellagic acid. However, in vivo conjugation of Uro-A to Uro-A glucuronide (Uro-A glur) dramatically hampers its activity. We describe here for the first time the tissue deconjugation of Uro-A glur to Uro-A after lipopolysaccharide (LPS)-induced inflammation, which could explain the systemic in vivo activity of free Uro-A in microenvironments subjected to inflammatory stimuli.

Buckwheat and buckwheat enriched products exert an anti-inflammatory effect on the myofibroblasts of colon CCD-18Co.

Buckwheat (BW) constitutes a good source of bioactive components that show anti-inflammatory effects in vitro and in vivo. The use of functional foods in the prevention and treatment of inflammatory bowel diseases (IBDs) has aroused increasing interest. This study investigates the effect of in vitro digested BW and BW-enriched products (BW-enriched wheat breads, roasted BW groats -fermented and non-fermented-, and BW sprouts) on colon myofibroblasts, the cells involved in the regulation of inflammatory response in the intestine. The cells were treated with different digested-BW products, alone or together with TNF-α (20 ng mL-1), and the effects on the cell migration, mitochondrial membrane potential and cell cycle, processes altered during intestinal inflammation, were investigated. A significant reduction in TNF-α-induced migration (25.5%, p < 0.05) and attenuation of the TNF-α-altered cell cycle (p < 0.05) was observed in myofibroblasts treated with BW-enriched white wheat bread. These results contribute to extend the beneficial effects derived from BW bioactive compounds, and suggest that BW consumption can exert beneficial effects on IBDs.

Urolithins, ellagitannin metabolites produced by colon microbiota, inhibit Quorum Sensing in Yersinia enterocolitica: Phenotypic response and associated molecular changes.

The mammalian enteropathogen Yersinia enterocolitica produces two main N-acylhomoserine lactones (AHLs) involved in Quorum Sensing (QS)-mediated infection processes, such as virulence, biofilm maturation and motility. Ellagitannin (ET)-rich fruits exhibit anti-QS activity but in vivo effects against intestinal pathogens may be associated to the ETs gut microbiota derived metabolites, urolithin-A (Uro-A) and urolithin-B (Uro-B). In this work we show that urolithins, at concentrations achievable in the intestine through the diet, reduce the levels of N-hexanoyl-l-homoserine lactone (C6-HSL) and N-(3-oxo-hexanoyl)-l-homoserine lactone (3-oxo-C6-HSL) in Y. enterocolitica and inhibit QS-associated biofilm maturation and swimming motility. These inhibitory effects were not associated to downregulation of the expression of some of the genes involved in the synthesis of AHLs (yenI and yenR) or in motility (flhDC, fliA, fleB). Our results suggest that urolithins may exert antipathogenic effects in the gut against Y. enterocolitica and highlight the need to investigate the antipathogenic in vivo properties of plant derived metabolites.