Citral alleviates peptidoglycan‐induced inflammation and disruption of barrier functions in porcine intestinal epithelial cells

Abstract

Peptidoglycan (PGN) is a major polymer in bacterial cell walls and may constrain gut functionality and lower intestinal efficiencies in livestock. Citral has been reported to exhibit antibacterial and anti‐inflammatory biological activities, improving the gastrointestinal function of swine. However, the protective effect of citral against PGN‐elicited cellular responses and possible underlying mechanisms are unknown. In this study, the porcine jejunal epithelial cell line (IPEC‐J2) was challenged with PGN from Staphylococcus aureus (S. aureus) or Bacillus subtilis (B. subtilis) to explore PGN‐induced inflammatory responses. Our data showed that the inflammatory response stimulated by PGN from harmful bacteria (S. aureus) was more potent than that from commensal bacteria (B. subtilis) in IPEC‐J2 cells. Based on the inflammatory model by PGN from S. aureus, it was demonstrated that PGN could significantly induce inflammatory cytokine production and influence nutrient absorption and barrier function in a dose‐dependent manner. However, the PGN‐mediated immune responses were remarkably suppressed by citral. In addition, citral significantly attenuated the effect of PGN on the intestine nutrient absorption and barrier function. The expression of TLR2 was strongly induced by PGN stimulation, which was suppressed by citral. All data nominated that citral downregulated PGN‐induced inflammation via TLR2‐mediated activation of the NF‐κB signaling pathway in IPEC‐J2 cells. Furthermore, the results also indicate that the PGN degradation through the inclusion of enzymes (e.g., muramidase) as well as the inclusion of citral for attenuating inflammation may improve pig gut health and functionality.

Endogenous chitinase might lead to differences in growth performance and intestinal health of piglets fed different levels of black soldier fly larva meal

“…MCFA can infiltrate the lipid membrane of pathogenic bacterial cell, thus resulting in the decrease of cytosolic pH ( Skrivanova et al., 2006 ). However, a higher abundance of potentially harmful bacteria, including Pasteurellaceae and Staphylococcaceae, was found in the gut of piglets from the BSF100 group compared to BSF0 ( Klinsoda et al., 2020 ; Li et al., 2022a ). High levels of chitin may be associated with the increase in pathogenic bacteria.…”

iE-DAP Induced Inflammatory Response and Tight Junction Disruption in Bovine Mammary Epithelial Cells via NOD1-Dependent NF-κB and MLCK Signaling Pathway

“…The results showed that iE-DAP significantly reduced the gene expression of ZO-1 and Occludin in BEMCs. In addition, the integrity of an epithelial barrier is generally evaluated with TEER, and increased leakage of FITC-dextran indicates the permeability of an epithelial barrier [ 35 , 36 ]. Therefore, the decreased TEER and increased paracellular dextran passage in the iE-DAP group indicated that iE-DAP impaired BMEC monolayer integrity.…”

Potential of Aromatic Plant-Derived Essential Oils for the Control of Foodborne Bacteria and Antibiotic Resistance in Animal Production: A Review

“…S. Typhimurium could decrease the expressions of Occludin and Claudin-1 and subsequently disrupt the intestinal epithelial barrier in broiler chickens [ 168 ]. Peptidoglycan from S. aureus induces intestinal inflammation and disrupts intestinal barrier functions through TLR2-regulated activation of the NF-κB pathway in porcine jejunal epithelial cells [ 169 ]. During foodborne infection, L. monocytogenes cross the intestinal mucosal barrier via Listeria adhesion protein, which could break down the epithelial tight junction barrier for bacteria to enter the lamina propria [ 170 ].…”