epiglucan and Endotoxemia

Topics: beta-Glucans; Dengue; Dysbiosis; Endotoxemia; Humans; Lipopolysaccharides; Severe Dengue

This study takes a novel approach to investigate the anti-inflammatory and antioxidant effects of prebiotic oat beta-glucan (OAT) and the probiotic Lactobacillus rhamnosus GG (LGG) against high-fat diets (HFD) by examining the fatty acid profiles in the gut-liver-brain axis.. HFD-fed C57BL/6N mice are supplemented with OAT and/or LGG for 17 weeks. Thereafter, mass spectrometry-based targeted lipidomics is employed to quantify short-chain fatty acids (SCFA), polyunsaturated fatty acids (PUFA), and oxidized PUFA products in the tissues. Acetate levels are suppressed by HFD in all tissues but reversed in the brain and liver by supplementation with LGG, OAT, or LGG + OAT, and in cecum content by LGG. The n-6/n-3 polyunsaturated fatty acid (PUFA) ratio is elevated by HFD in all tissues but is lowered by LGG and OAT in the cecum and the brain, and by LGG + OAT in the brain, suggesting the anti-inflammatory property of LGG and OAT. LGG and OAT synergistically, but not individually attenuate the increase in non-enzymatic oxidized products, indicating their synbiotic antioxidant property.. The regulation of the fatty acid profiles by LGG and OAT, although incomplete, but demonstrates their anti-inflammatory and antioxidant potentials in the gut-liver-brain axis against HFD.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Avena; beta-Glucans; Brain; Caco-2 Cells; Diet, High-Fat; Dietary Supplements; Eating; Endotoxemia; Fatty Acids, Volatile; Humans; Lacticaseibacillus rhamnosus; Lipopolysaccharides; Liver; Male; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Probiotics

Elevated blood endotoxin levels are frequently reported in the dialysis population and are strongly linked with inflammation, a major predictor of mortality. Virtually all studies have employed the Limulus Amoebocyte Lysate (LAL) assay to detect endotoxin. However this assay is not endotoxin-specific and can be activated by (1→3)-β-glucan (BG), a component of fungal cell walls leading to false positive signals. Very few studies have taken account of this. We examined the influence of BG-based activation of the LAL assay on the detection of endotoxemia in this setting.. We measured plasma endotoxin levels in 50 hemodialysis patients with and without the use of BG-blocking buffers. These buffers inhibit BG activation of the LAL assay to ensure that any signal detected is endotoxin-specific. Blood samples were measured for BG, interleukin-6 (IL-6), tumor necrosis factor-alfa (TNF-α) to examine the association between endotoxin signals, BG and inflammation.. Endotoxin signals were detected in 50% of patients. On repeat measurement with a BG-blocking buffer, all detected endotoxin signals were extinguished. No patient had detectable endotoxemia. Plasma BG levels were significantly elevated in 58% of patients and were higher in those with detectable endotoxin signals using the LAL assay without BG-blocking buffers (78vs.54pg/mL;p<0.001). Endotoxin signal and BG levels did not correlate with levels of TNF-α or IL-6.. Use of the LAL assay for blood endotoxin detection in dialysis patients has its limitations due to high blood BG. Endotoxemia frequently reported in non-infected hemodialysis patients may be artefactual due to BG interference.

Topics: Aged; Artifacts; beta-Glucans; Buffers; Cross-Sectional Studies; Endotoxemia; Endotoxins; False Positive Reactions; Female; Humans; Limulus Test; Male; Middle Aged; Renal Dialysis

Lipopolysaccharide (LPS)-induced endotoxemia can cause serious organ damage such as acute lung injury and death by triggering the secretion of proinflammatory cytokines and acute-phase reactants. The goal of this study was to evaluate the effects of β-glucan on inflammatory mediator levels and histopathological changes in LPS-induced endotoxemia.. Forty-seven male Wistar albino rats were randomly allocated into four groups as follows: control group, LPS group (10 mg/kg LPS), LPS + β-glucan group (100 mg/kg β-glucan before LPS administration), and β-glucan group. Twelve hours after LPS administration, lung and serum samples were collected. Concentrations of IL-6, IL-8, C-reactive protein (CRP), and procalcitonin were measured in the serum at hours 0 (basal) and 12. The severity of lung damage was assessed by an appropriate histopathological scoring system.. Serum levels of CRP in the LPS group at 12 h were significantly higher than in the other groups, whereas serum IL-6 levels in the LPS and LPS + β-glucan groups at 12 h were significantly decreased. The mean histopathological damage score of the LPS group was slightly higher than that of the LPS + β-glucan group. Moreover, mortality rate was significantly decreased in the LPS + β-glucan group versus the LPS group.. β-glucan reduces endotoxemia-induced mortality and might be protective against endotoxemia-induced lung damage.

Topics: Acute Lung Injury; Acute-Phase Proteins; Animals; beta-Glucans; Biological Factors; C-Reactive Protein; Endotoxemia; Interleukin-6; Interleukin-8; Lipopolysaccharides; Lung; Male; Protective Agents; Rats; Rats, Wistar

Nonalcoholic steatohepatitis (NASH) is part of the spectrum of nonalcoholic fatty liver disease. However, there are few suitable animal models to study the pathogenesis of NASH or very limited advances in the prevention. Our aims were to establish a mouse model of NASH by intraperitoneally injecting lipopolysaccharide (LPS) at a dose of 1.5 mg per kg body weight per day for 6 weeks and to investigate the potential inhibitory effects of oat β-glucan (1%, 5%, or 10%) added to a specific pathogen-free diet. Intraperitoneal injection of LPS for 6 weeks increased serum LPS levels; decreased serum glucagon-like peptide-2 levels; triggered abnormal aminotransferase activity, glucose intolerance, and insulin resistance; and increased hepatic proinflammatory cytokines (tumor necrosis factor-α, interleukin-6, interleukin-1β), triglyceride, and malonyl dialdehyde levels; but reduced hepatic superoxide dismutase activity. Histologic evaluation revealed evidence of hepatic steatosis, inflammation, and mild necrosis in LPS-treated mice. Dietary supplementation of oat β-glucan prevented most of the LPS-induced metabolic disorders, and improved hepatic steatosis and inflammation, although a dose-dependent effect was not observed. In conclusion, oat β-glucan could inhibit LPS-induced NASH in mice.

Topics: Animals; Avena; beta-Glucans; Disease Models, Animal; Dose-Response Relationship, Drug; Endotoxemia; Fatty Liver; Glucagon-Like Peptide 2; Glucose Intolerance; Inflammation; Insulin Resistance; Interleukin-1beta; Interleukin-6; Lipopolysaccharides; Liver; Male; Malondialdehyde; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Oxidative Stress; Superoxide Dismutase; Transaminases; Triglycerides; Tumor Necrosis Factor-alpha; Weight Gain

Previous studies in our laboratory have demonstrated the downregulation of surface expression of scavenger receptor (SR) and upregulation of CD14 in the presence of endotoxemia, which directly correlates to the excessive inflammatory response in lung injuries. This study aims to analyze the dynamics of the expressions of SR and CD14 in traumatic endotoxemia, and to investigate the receptor mechanism of immunomodulator, carboxymethyl-beta-1, 3-glucan (CMG), on the protection of traumatic infections.. By using a sublethal fracture plus endotoxemia model, experimental mice were assigned to sham group (Sham), trauma group (T), traumatic endotoxemia group (TE), and traumatic endotoxemia plus CMG group (TE + C). Alveolar macrophages were isolated from each group. Expressions of SR and CD14 were examined at the cell and tissue levels by immunohistochemistry assay. The effects of CMG on the phagocytosis of alveolar macrophages, tissue injury, and mortality were also determined.. Expressions of SR and CD14 in lungs and livers decreased and increased, respectively. Alteration of SR and CD14 levels was more evident in lungs than in livers in posttraumatic endotoxemia. CMG up-regulated the SR expression in lipopolysaccharide-stimulated alveolar macrophages, alleviated the tissue injury, reduced mice mortality, and increased the opsonin-independent phagocytosis of Staphylococcus aureus, which was inhibited by SR mono-antibody.. Significant correlation was found between inflammatory responses and the imbalance between SR and CD14 in posttraumatic endotoxemia. The more dramatic changes in lungs might be related to the sequential preferred injury in uncontrolled inflammation. CMG could be a promising bioactive reagent in immunomodulating sepsis.

Topics: Animals; beta-Glucans; Endotoxemia; Escherichia coli; Female; Lipopolysaccharide Receptors; Liver; Lung; Macrophages, Alveolar; Male; Mice; Phagocytosis; Receptors, Scavenger; Staphylococcus aureus; Up-Regulation; Wounds and Injuries

beta-Glucans are glucose polymers with a variety of stimulatory effects on the immune system. The objective of this study was to determine the effect of prophylactic oral administration of soluble Saccharomyces cerevisiae-derived beta-1,3/1,6-glucan (SBG) on the outcome of experimental endotoxaemia and shock-associated organ injury. Male Wistar rats were pretreated with SBG orally (SBGpo, 20 mg/kg/day) for 14 days, subcutaneously (SBGsc, 2 mg/kg/day) for 3 days, or vehicle (placebo). Rats were anaesthetized and subjected to endotoxaemia by intravenous infusion of Escherichia coli lipopolysaccharide (LPS) (6 mg/kg) or saline infusion (sham). We observed significant levels of plasma beta-glucan in the SBGpo group (P<0 x 5), although the SBGsc group had levels approximately 40-fold higher despite a 10-fold lower dose. SBG prophylaxis caused enhanced blood pressure recovery following LPS-induced blood pressure collapse. Oral treatment with SBG attenuated the LPS-induced rise in plasma creatinine levels (P<0 x 05), indicating protection against renal injury. SBG also attenuated the plasma levels of aspartate aminotransferase and alanine aminotransferase (SBGpo, P<0 x 01; SBGsc, P<0 x 01), indicating protection against LPS-induced hepatic injury. A moderate increase in baseline interleukin (IL)-1beta levels was observed in the SBGsc group (P< 0 x 05). In the LPS-challenged rats, plasma levels of proinflammatory cytokines was moderately reduced in both SBG-treated groups compared to placebo. SBG treatment, particularly oral administration, had a striking effect on the haemodynamics of LPS-treated rats, although only a minute fraction of the orally administered beta-glucan translocated to the circulation. Enhanced organ perfusion may thus be responsible for the attenuated levels of indicators of kidney and liver injury seen in SBG-treated rats.

Topics: Administration, Oral; Animals; beta-Glucans; Blood Pressure; Cytokines; Endotoxemia; Injections, Subcutaneous; Lipopolysaccharides; Male; Multiple Organ Failure; Rats; Rats, Wistar; Saccharomyces cerevisiae; Shock, Septic