Effects of Lactobacillus rhamnosus DSM7133 on Intestinal Porcine Epithelial Cells.

Antimicrobial resistance is one of the biggest health challenges nowadays. Probiotics are promising candidates as feed additives contributing to the health of the gastrointestinal tract. The beneficial effect of probiotics is species/strain specific; the potential benefits need to be individually assessed for each probiotic strain or species. We established a co-culture model, in which gastrointestinal infection was modeled using Escherichia coli (E. coli) and Salmonella enterica serovar Typhimurium (S. enterica serovar Typhimurium). Using intestinal porcine epithelial cells (IPEC-J2), the effects of pre-, co-, and post-treatment with Lactobacillus (L.) rhamnosus on the barrier function, intracellular (IC) reactive oxygen species (ROS) production, proinflammatory cytokine (IL-6 and IL-8) response, and adhesion inhibition were tested. E. coli- and S. Typhimurium-induced barrier impairment and increased ROS production could be counteracted using L. rhamnosus (p < 0.01). S. Typhimurium-induced IL-6 production was reduced via pre-treatment (p < 0.05) and post-treatment (p < 0.01); increased IL-8 secretion was decreased via pre-, co-, and post-treatment (p < 0.01) with L. rhamnosus. L. rhamnosus demonstrated significant inhibition of adhesion for both S. Typhimurium (p < 0.001) and E. coli (p < 0.001 in both pre-treatment and post-treatment; p < 0.05 in co-treatment). This study makes a substantial contribution to the understanding of the specific benefits of L. rhamnosus. Our findings can serve as a basis for further in vivo studies carried out in pigs and humans.

Effect of hydroxylated and methylated flavonoids on cytochrome P450 activity in porcine intestinal epithelial cells.

Cytochrome P450 (CYP) oxidases are among the main metabolizing enzymes that are responsible for the transformation of xenobiotics, including clinically important drugs. Their activity can be influenced by several compounds leading to decreased efficacy or increased toxicity of co-administered medicines. Flavonoids exert various beneficial effects on human and animal health; therefore they are used as food and feed supplements. However, they are also well-known for their CYP modulating potential. Since the amount of CYP enzymes is highest in the liver, interaction studies are mainly conducted in hepatocytes, however, CYP activity in the gastrointestinal tract is also remarkable. In this study, effects of apigenin (API), quercetin (QUE) and their methylated derivatives trimethylapigenin (TM-API), 3-O-methylquercetin (3M-QUE) and 3',7-di-O-methylquercetin (3'7DM-QUE) on the CYP enzyme activity was examined in IPEC-J2 porcine intestinal epithelial cells. Potential food-drug interactions were studied using flavonoid treatment in combination with inducer and inhibitor compounds. API, TM-API, QUE and 3M-QUE significantly inhibited the CYP3A29 enzyme, while 3'7DM-QUE did not alter its activity. Enzyme inhibition has also been observed in case of some food-drug combinations. Our results support previous findings about CYP modulating effects of flavonoids and highlights the possibility of interactions when flavonoid-containing supplements are consumed during drug treatments.

The Impact of Quercetin and Its Methylated Derivatives 3-o-Methylquercetin and Rhamnazin in Lipopolysaccharide-Induced Inflammation in Porcine Intestinal Cells.

Oxidative stress in the small intestine can lead to inflammation and barrier malfunction. The present study describes the effect of quercetin (Q), 3-o-methylquercetin (QM), and rhamnazin (R) on cell viability, paracellular permeability, production of intracellular reactive oxygen species (ROS), extracellular hydrogen peroxide (H2O2), and interleukin-6 (IL-6) after challenging jejunal cells (IPEC-J2) with different types (Salmonella enterica ser. Typhimurium, Escherichia coli O111:B4, and E. coli O127:B8) of lipopolysaccharides (LPS) applied in 10 µg/mL concentration. The intracellular ROS level increased after all LPS treatments, which could be decreased by all tested flavonoid compounds in 50 µM concentration. Extracellular H2O2 production significantly increased after Q and R treatment (50 µM). S. Typhimurium LPS could significantly increase IL-6 production of enterocytes, which could be alleviated by Q, QM, and R (50 µM) as well. Using fluorescein isothiocyanate dextran (FD4) tracer dye, we could demonstrate that S. Typhimurium LPS significantly increased the permeability of the cell layer. The simultaneous treatments of S. Typhimurium LPS and the flavonoid compounds showed no alteration in FD4 penetration compared to untreated cells. These results highlight that Q, QM, and R are promising substances that can be used to protect intestinal epithelial cells from the deteriorating effects of oxidative stress.

Antioxidant Activity of Flavonoids in LPS-Treated IPEC-J2 Porcine Intestinal Epithelial Cells and Their Antibacterial Effect against Bacteria of Swine Origin.

Beneficial effects of flavonoids are widely known in human medicine, but less information is available about their veterinary usage. Based on their antioxidant and antibacterial activity, proanthocyanidins (PAs) and luteolin (LUT) might be used in the prevention and treatment of gastrointestinal infections in swine. In this study, in vitro beneficial effects of grape seed oligomeric proanthocyanidins (GSOPs) and LUT were investigated against bacterial endotoxin (LPS)-induced oxidative stress in IPEC-J2 porcine epithelial intestinal cells. Furthermore, antibacterial effects of GSOP and LUT were assessed against field isolates of Escherichia coli and Salmonella enterica ser. Typhimurium. Both GSOP and LUT were found to possess potent in vitro antioxidant activity in LPS-treated IPEC-J2 cells; furthermore, they showed a bacteriostatic effect against the tested bacterial strains of porcine origin. Both flavonoids seem to be effective in the protection of porcine intestinal epithelial cells against Gram-negative bacteria in vitro, but further in vivo studies are necessary to confirm these activities and to establish their optimal dosage regimen for future usage in veterinary practice.