Leucrose, a natural sucrose isomer, suppresses dextran sulfate sodium (DSS)-induced colitis in mice by regulating macrophage polarization via JAK1/STAT6 signaling

Oral Excretion Kinetics of Food-Additive Silicon Dioxides and Their Effect on In Vivo Macrophage Activation

A food additive, silicon dioxide (SiO2) is commonly used in the food industry as an anti-caking agent. The presence of nanoparticles (NPs) in commercial food-grade SiO2 has raised concerns regarding their potential toxicity related to nano size. While recent studies have demonstrated the oral absorption and tissue distribution of food-additive SiO2 particles, limited information is available about their excretion behaviors and potential impact on macrophage activation. In this study, the excretion kinetics of two differently manufactured (fumed and precipitated) SiO2 particles were evaluated following repeated oral administration to rats for 28 d. The excretion fate of their intact particles, decomposed forms, or ionic forms was investigated in feces and urine, respectively. Monocyte uptake, Kupffer cell activation, and cytokine release were assessed after the oral administration of SiO2 particles. Additionally, their intracellular fates were determined in Raw 264.7 cells. The results revealed that the majority of SiO2 particles were not absorbed but directly excreted via feces in intact particle forms. Only a small portion of SiO2 was eliminated via urine, predominantly in the form of bioconverted silicic acid and slightly decomposed ionic forms. SiO2 particles were mainly present in particle forms inside cells, followed by ionic and silicic acid forms, indicating their slow conversion into silicic acid after cellular uptake. No effects of the manufacturing method were observed on excretion and fates. Moreover, no in vivo monocyte uptake, Kupffer cell polarization, or cytokine release were induced by orally administered SiO2 particles. These finding contribute to understanding the oral toxicokinetics of food-additive SiO2 and provide valuable insights into its potential toxicity.

Comprehensive utilization of sucrose resources via chemical and biotechnological processes: A review

Sucrose, one of the most widespread disaccharides in nature, has been available in daily human life for many centuries. As an abundant and cheap sweetener, sucrose plays an essential role in our diet and the food industry. However, it has been determined that many diseases, such as obesity, diabetes, hyperlipidemia, etc., directly relate to the overconsumption of sucrose. It arouses many explorations for the conversion of sucrose to high-value chemicals. Production of valuable substances from sucrose by chemical methods has been studied since a half-century ago. Compared to chemical processes, biotechnological conversion approaches of sucrose are more environmentally friendly. Many enzymes can use sucrose as the substrate to generate functional sugars, especially those from GH68, GH70, GH13, and GH32 families. In this review, enzymatic catalysis and whole-cell fermentation of sucrose for the production of valuable chemicals were reviewed. The multienzyme cascade catalysis and metabolic engineering strategies were addressed.

Dietary Ethanolamine Plasmalogen Alleviates DSS-Induced Colitis by Enhancing Colon Mucosa Integrity, Antioxidative Stress, and Anti-inflammatory Responses via Increased Ethanolamine Plasmalogen Molecular Species: Protective Role of Vinyl Ether Linkages

Dietary ethanolamine plasmalogen (PlsEtn) has been reported to have several health benefits; however, its functional role during colon pathophysiology remains elusive. The present study investigated the anticolitis effect of dietary ethanolamine glycerophospholipids (EtnGpls) with high PlsEtn from ascidian muscle (86.2 mol %) and low PlsEtn from porcine liver (7.7 mol %) in dextran sulfate sodium (DSS)-induced colitis in mice. Dietary EtnGpls lowered myeloperoxidase activity, thiobarbituric acid-reactive substances, proinflammatory cytokines and proapoptosis-related protein levels in colon mucosa after 16 days of DSS treatment, with ascidian muscle (0.1% EtnGpl in diet) showing higher suppression than porcine liver (0.1% EtnGpl in diet). Moreover, dietary EtnGpls suppressed DSS symptoms after 38 days of DSS treatment as evidenced by increased body weight, colon length, and ameliorated colon mucosa integrity. Additionally, dietary EtnGpls elevated short-chain fatty acid production in DSS-treated mice. Altogether, these results indicate the potential of utilizing diets with abundant PlsEtn for the prevention of colon inflammation-related disorders.

Potential Role of Heme Oxygenase-1 in the Resolution of Experimentally Induced Colitis through Regulation of Macrophage Polarization

Background/Aims

Heme oxygenase-1 (HO-1) plays a central role in cellular defense against inflammatory insults, and its induction in macrophages potentiates their efferocytic activity. In this study, we explored the potential role of macrophage HO-1 in the resolution of experimentally induced colitis.

Methods

To induce colitis, male C57BL/6 mice were treated with 2% dextran sulfate sodium (DSS) in the drinking water for 7 days. To investigate efferocytosis, apoptotic colon epithelial CCD 841 CoN cells were coincubated with bone marrow-derived macrophages (BMDMs).

Results

Administration of the HO-1 inhibitor zinc protoporphyrin IX (ZnPP) blunted the resolution of DSS-induced intestinal inflammation and expression of the proresolving M2 macrophage marker CD206. BMDMs treated with apoptotic colonic epithelial cells showed significantly elevated expression of HO-1 and its regulator Nrf2. Under the same experimental conditions, the proportion of CD206-expressing macrophages was also enhanced. ZnPP treatment abrogated the upregulation of CD206 expression in BMDMs engulfing apoptotic colonic epithelial cells. This result was verified with BMDMs isolated from HO-1-knockout mice. BMDMs, when stimulated with lipopolysaccharide, exhibited increased expression of CD86, a marker of M1 macrophages. Coculture of lipopolysaccharide-stimulated BMDMs with apoptotic colonic epithelial cell debris dampened the expression of CD86 as well as the pro-inflammatory cytokines in an HO-1-dependent manner. Genetic ablation as well as pharmacologic inhibition of HO-1 significantly reduced the proportion of efferocytic BMDMs expressing the scavenger receptor CD36.

Conclusions

HO-1 plays a key role in the resolution of experimentally induced colitis by modulating the polarization of macrophages.