The Role of Iron Metabolism in Sepsis-associated Encephalopathy: a Potential Target

Anthocyanins-rich cranberry extract attenuates DSS-induced IBD in an intestinal flora independent manner

Cranberry is abundantly rich in anthocyanins, a type of flavonoid with potent antioxidant properties and the resistance against certain diseases. In this study, anthocyanin-rich cranberry extract was extracted, purified, and its components were analyzed. 92.18 % of anthocyanins was obtained and the total content of anthocyanins was 302.62 mg/g after AB-8 resin purification. Quantification analysis showed that the extract mainly contained cyanidin-3-galactoside, procyanidin B2 and procyanidin B4. Then we explored its effects on dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD) in mice. The supplementation of cranberry extract resulted in an alleviation of IBD symptoms, evidenced by improvements in the disease activity index (DAI), restoration of colon length and colonic morphology. Cranberry extract reversed the elevated iron and malondialdehyde (MDA) levels and restored glutathione (GSH) levels in IBD mice. Further analysis revealed that cranberry modulated ferroptosis-associated genes and reduced expression of pro-inflammatory cytokines. Although cranberry influenced the intestinal flora balance by reducing Proteobacteria and Escherichia-Shigella, and increasing Lactobacillus, as well as enhancing SCFAs content, these effects were not entirely dependent on intestinal flora modulation, as indicated by antibiotic intervention and fecal microbiota transplantation (FMT) experiments. In conclusion, our findings suggest that the beneficial impact of cranberry extract on IBD may primarily involve the regulation of colonic ferroptosis, independent of significant alterations in intestinal flora.

The role of the peripheral system dysfunction in the pathogenesis of sepsis-associated encephalopathy

Sepsis is a condition that greatly impacts the brain, leading to neurological dysfunction and heightened mortality rates, making it one of the primary organs affected. Injury to the central nervous system can be attributed to dysfunction of various organs throughout the entire body and imbalances within the peripheral immune system. Furthermore, central nervous system injury can create a vicious circle with infection-induced peripheral immune disorders. We collate the pathogenesis of septic encephalopathy, which involves microglial activation, programmed cell death, mitochondrial dysfunction, endoplasmic reticulum stress, neurotransmitter imbalance, and blood-brain barrier disruption. We also spotlight the effects of intestinal flora and its metabolites, enterocyte-derived exosomes, cholinergic anti-inflammatory pathway, peripheral T cells and their cytokines on septic encephalopathy.