Lactobacilli Reduce Chemokine IL-8 Production in Response to TNF-αandSalmonellaChallenge of Caco-2 Cells

Abstract

The probiotic properties of two selected lactobacilli strains were assessed. L. salivarius and L. plantarum displayed higher hydrophobicity (48% and 54%, resp.) and coaggregation ability with four pathogens (from 7.9% to 57.5%). L. salivarius and L. plantarum had good inhibitory effects on S. aureus (38.2% and 49.5%, resp.) attachment to Caco-2 cells. Live lactobacilli strains and their conditioned media effectively inhibited IL-8 production (<14.6 pg/mL) in TNF-α-induced Caco-2 cells. Antibiotic-treated and the sonicated lactobacilli also maintained inhibitory effects (IL-8 production from 5.0 to 36.3 pg/mL); however, the heat-treated lactobacilli lost their inhibitory effects (IL-8 production from 130.2 to 161.0 pg/mL). These results suggest that both the structural components and the soluble cellular content of lactobacilli have anti-inflammatory effects. We also found that pretreatment of Caco-2 cells with lactobacilli inhibited S. typhimurium-induced IL-8 production (<27.3 pg/mL). However, lactobacilli did not inhibit IL-8 production in Caco-2 cells pretreated with S. typhimurium. These results suggest that the tested lactobacilli strains are appropriate for preventing inflammatory diseases caused by enteric pathogens but not for therapy. In short, L. salivarius and L. plantarum are potential candidates for the development of microbial ecological agents and functional foods.

Effect of fermented milk from Lactococcus lactis ssp. cremoris strain JFR1 on Salmonella invasion of intestinal epithelial cells

“…There is considerable evidence reporting that LAB and their fermented milks display an overall modulating effect in in vitro studies, specifically in the presence of pathogens, which stimulate inflammatory responses (Zeinhom et al, 2012;Zagato et al, 2014;Chen et al, 2016;Acurcio et al, 2017;Lépine et al, 2018). Although similar to this study, others have reported considerably less production of IL-8 by Caco-2 cells compared with other cell types, including HT-29 and its subsets (Eckmann et al, 1993;Zhang et al, 2005;Ren et al, 2013). From this research, HT29-MTX cells treated with milk fermented by JFR1+ and JFR1− strains showed lower production of IL-8 compared with both the Salmonella-positive control and GDL chemically acidified milk control, suggesting that only bacterial fermented milk could demonstrate this effect.…”

miR-200b inhibits TNF-α-induced IL-8 secretion and tight junction disruption of intestinal epithelial cells in vitro

“…3916; Costar, Corning) with 480-nm excitation and 520-nm emission filters. The paracellular flux was determined from a standard curve and normalized to NC group (33).…”

“…Therefore, it makes sense to inhibit IL-8 expression to relieve the acute onset of IBD and prevent the advancement of the inflammation-associated colonic carcinoma. It is acknowledged that IL-8 transcription is regulated by the JNK/c-Jun/AP-1 pathway(23,33). TNF-␣ results in a high level of active phosphorylated c-Jun NH 2terminal kinase (p-JNK), which could phosphorylate c-Jun.…”

Inhibition of lncRNA NEAT1 suppresses the inflammatory response in IBD by modulating the intestinal epithelial barrier and by exosome-mediated polarization of macrophages

“…no. 3916, Costar; Corning Incorporated, Corning, NY, USA) with 480 nm excitation and 520 emission filters (29). The paracellular flux was determined from a standard curve and normalized to the negative control group.…”