Bacterial Metabolite Reuterin Attenuated LPS-Induced Oxidative Stress and Inflammation Response in HD11 Macrophages

Abstract

Reuterin is well-known for its broad-spectrum antimicrobial ability, while the other potential bioactivity is not yet clear. The present study aims to investigate the immunomodulatory activity of reuterin on chicken macrophage HD11 cells for the first time and evaluate whether reuterin is able to regulate the lipopolysaccharide-stimulated inflammatory response. The results showed that the safe medication range of reuterin was less than 250 μM. Reuterin treatment for 6 h decreased the transcriptional of CD86, IL-1β and iNOS and increased the expression of CD206 in a dose-dependent way, but reuterin treatment for 12 h contrary increased the expression of IL-1β, IL-6 and IL-10. However, it was noticed that reuterin treatment for 12 h significantly decreased the production of reactive oxygen species (ROS) and suppressed the phagocytosis activity of HD11 macrophages against bacteria. Further, the results showed that preincubation or coincubation with reuterin significantly attenuated the promotive effects of lipopolysaccharide (LPS) on transcription of proinflammatory cytokines (including IL-1β, IL-6 and TNF-α) and obviously inhibited nitric oxide (NO) production as well as the protein expression of inducible nitric oxide synthase (iNOS). Meanwhile, Mechanism studies implied that reuterin might exert an anti-inflammatory effect on LPS-stimulated cells by downregulating the expression of TLR4/MyD88/TRAF6 and blocking the activation of NF-κB as well as MAPKs signaling pathways. Additionally, it was found that both pretreatment and cotreatment with reuterin remarkably inhibited the oxidative stress induced by LPS stimulation by activating the Nrf2/HO-1 signaling pathway and enhancing the activities of antioxidative enzymes. These findings suggested the immunoregulatory function of reuterin and indicated this bacterial metabolite was able to inhibit the inflammation and oxidative stress of HD11 macrophages once exposed to LPS stimulation.

Lactobacillus reuteri in digestive system diseases: focus on clinical trials and mechanisms

“…The molecular mechanism might be explained by that reuterin can increase reactive oxygen species and thus reduce ribosomal biogenesis by selectively binding to cysteine residues, accompanied by increased gene expression downstream of nuclear factor erythroid-derived 2 (Nrf-2) (Bell et al, 2022). However, it was also revealed in vitro experiments that reuterin treatment at a dose of 250mM significantly suppressed LPS-induced oxidative stress by enhancing Nrf-2 expression and reducing reactive oxygen species production in HD11 macrophage cells (Xu et al, 2022). These data revealed that the effects of reuterin depend on certain cell types, reuterin concentration, and stimulation time.…”

Glycerol monolaurate regulates apoptosis and inflammation by suppressing lipopolysaccharide-induced ROS production and NF-κB activation in avian macrophages

“…HD11 cells in the logarithmic growth phase were resuspended in a completed medium at a concentration of 5 × 10 5 cells/mL and inoculated into a 6-well plate at 2 mL per well. After 24 h of culture, the cells were incubated with or without GML (10 μg/mL) for 12 h, followed by incubation with or without LPS challenge (2 μg/mL) for a further 12 h as previously described ( Xu et al, 2022 ).…”