Reduction In Endotoxin Levels Research Articles

Gut microbiota-derived indole compounds attenuate metabolic dysfunction-associated steatotic liver disease by improving fat metabolism and inflammation

ABSTRACT Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease, and its prevalence has increased worldwide in recent years. Additionally, there is a close relationship between MASLD and gut microbiota-derived metabolites. However, the mechanisms of MASLD and its metabolites are still unclear. We demonstrated decreased indole-3-propionic acid (IPA) and indole-3-acetic acid (IAA) in the feces of patients with hepatic steatosis compared to healthy controls. Here, IPA and IAA administration ameliorated hepatic steatosis and inflammation in an animal model of WD-induced MASLD by suppressing the NF-κB signaling pathway through a reduction in endotoxin levels and inactivation of macrophages. Bifidobacterium bifidum metabolizes tryptophan to produce IAA, and B. bifidum effectively prevents hepatic steatosis and inflammation through the production of IAA. Our study demonstrates that IPA and IAA derived from the gut microbiota have novel preventive or therapeutic potential for MASLD treatment.

Depyrogenation using Plasmas: A Novel Approach for Endotoxin Deactivation Using a Dielectric Barrier Discharge at Atmospheric Pressure.

Developing a low-cost depyrogenation process is vital in extending medical applicability of polymers that can be used in medicine. We present an overview of the plasma-based depyrogenation literature and address the need to develop a non-thermal plasma-based depyrogenation process for delicate materials such as chitosan. We present a low-cost plasma apparatus to treat chitosan powder in hermetically sealed bags. We decouple the experiments into two; depyrogenation experiments for dried standard endotoxin on glass slides, and chitosan modifications analysis through FTIR spectroscopy. We demonstrate depyrogenation efficacy with up to a 4-log reduction in endotoxin levels and discuss minor changes observed in plasma-treated chitosan.

Effect of three Mechanical Systems on Removal of Endotoxins from Asymptomatic Necrotic teeth with apical Periodontitis. (A randomized clinical trial)

Objective: The present study's objective was to evaluate the percentage of endotoxin diminution after mechanical instrumentation of asymptomatic necrotic teeth with apical periodontitis using three mechanical systems. Materials and Methods: One hundred and eighty patients between 18 and 65 participated in this research. Thirty-five of 140 teeth were selected for the four enlargement techniques. Control group, TFA, WOG, and PTN groups received final flushing with 6oC 17% EDTA solution gently administered to the WL through a cold (6oC) sterile metallic micro-cannula attached to the Endovac system (Kerr Endo) for one minute. Two samples of the canal were obtained using a sterile paper cone (size 30) introduced into the canal´s full length. Results: Results showed a statistically significant difference between the two groups in the percentage reduction of endotoxin levels (P-value <0.001, Effect size = 0.598). Group PTN showed a statistically significantly lower median % reduction in endotoxin quantities than Group WOG and TFA. Conclusion: Under this study's conditions, it can be concluded that the PTN system was more effective in endotoxins reduction in teeth with necrotic pulps. When the RCT is correctly instrumented, single visit RCT can be as effective as a multiple visit treatment.

Proinflammatory Activity of Primarily Infected Endodontic Content against Macrophages after Different Phases of the Root Canal Therapy

IntroductionThis study investigated the presence of target bacterial species and the levels of endotoxins in teeth with apical periodontitis. Levels of inflammatory mediators (interleukin [IL]-1β and tumor necrosis factor [TNF]-α) were determined after macrophage stimulation with endodontic content after different phases of endodontic therapy using different irrigants. MethodsThirty primarily infected root canals were randomly assigned into 3 groups according to the irrigant used for root canal preparation (n = 10 per group): GI: 2.5% sodium hypochlorite, GII: 2% chlorhexidine gel, and GIII (control group): saline solution. Root canal samples were taken by using paper points before (s1) and after root canal instrumentation (s2), subsequently to 17% EDTA (s3), after 30 days of intracanal medication (Ca[OH]2 + saline solution) (s4), and before root canal obturation (s5). Polymerase chain reaction (16S recombinant DNA) and limulus amebocyte lysate assay were used for bacterial and endotoxin detection, respectively. Macrophages were stimulated with the root canal contents for IL-1β/TNF-α measurement using enzyme-linked immunosorbent assay. ResultsPorphyromonas gingivalis (17/30), Porphyromonas endodontalis (15/30), and Prevotella nigrescens (11/30) were the most prevalent bacterial species. At s1, endotoxins were detected in 100% of the root canals (median = 32.43 EU/mL). In parallel, substantial amounts of IL-1β and TNF-α were produced by endodontic content-stimulated macrophages. At s2, a significant reduction in endotoxin levels was observed in all groups, with GI presenting the greatest reduction (P < .05). After a root canal rinse with EDTA (s3), intracanal medication (s4), and before root canal obturation (s5), endotoxin levels reduced without differences between groups (P < .05). IL-1β and TNF-α release decreased proportionally to the levels of residual endotoxin (P < .05). ConclusionsRegardless of the use of sodium hypochlorite or CHX, the greatest endotoxin reduction occurs after chemomechanical preparation. Increasing steps of root canal therapy associated with intracanal medication enhances endotoxin reduction, leading to a progressively lower activation of proinflammatory cells such as macrophages

Root canal content from primary endodontic infection and upregulation of gelatinases in fibroblast cells.

To investigate endotoxin levels from primary endodontic infections before and after chemomechanical preparation (CMP) and to determine their antigenicity against 3T3 fibroblasts through gelatinolytic activity of matrix metalloproteinases (MMPs). Twenty-four root canals with primary endodontic infection and apical periodontitis were selected. Samples were collected using paper points before (S1) and after chemomechanical preparation (CMP) (S2). The limulus amebocyte lysate assay was used for endotoxin measurement. Fibroblasts were stimulated with root canal contents for 24h. Supernatants of cell cultures stimulated with root canal contents were collected after 24h to determine the levels of MMP-2 and MMP-9 gelatinolytic activity using the zymography technique. Friedman and Wilcoxon tests were used to compare the amount of endotoxin before (S1) and after CMP (S2) (P<0.05). Data obtained from gelatinolytic activity were analysed using anova and Tukey's tests (P<0.05). Endotoxin was recovered in 100% of the samples. There was a significant reduction in endotoxin levels after CMP (P<0.05). A correlation was found between the levels of endotoxins and MMP-2 expression (P<0.05). Root canal contents of initial samples (S1) induced significantly greater MMP-2 expression by fibroblasts when compared to S2 and the nonstimulated group (P<0.05). No gelatinolytic activity of MMP-9 was observed in S1, S2 and control group. Root canal contents from primary endodontic infections had gelatinolytic activity for MMP-2. Moreover, CMP was effective in reducing endotoxin levels and their antigenicity against fibroblasts on gelatinolytic activity.

Removal of oral Prevotella intermedia Endotoxin by octyl phenyl polyoxyethylene ether extraction method

To investigate an effective purification method for removing endotoxin from Prevotella intermedia. The main protein ingredients of bacteria prepared from ammonium sulfate precipitation were further treated with octyl phenyl polyoxyethylene ether (Triton X-114), and then processed at 4°C, 37°C and 25°C. The obtained aqueous phase after at least two more cycle repeated operations was assayed for endotoxin by Western blotting, LAL-clotting method, in vitro cell stimulation and in vivo animal experiments. Western blotting and LAL-clotting method demonstrated that the reduction in endotoxin level was greater than 99.99% and recovery of the proteins after endotoxin removal was greater than 90% with Triton X-114 treatment for 3 cycles. The cytokines expression level was lower in both in vitro cell stimulation and in vivo animal experiments than in untreated group (P < 0.05). The extraction method provides a new choice for endotoxin removal from large volumes of the oral Prevotella intermedia.

Inhibitory effects of taurine and oat fiber on intestinal endotoxin release in rats

Numerous studies have demonstrated that endotoxin plays an important role in the development and progression of hepatic cirrhosis. However, there is no effective remedy for the prevention and treatment of intestinal endotoxemia. Taurine has been reported to have beneficial effects on endotoxemia. Oats have been shown to absorb intestinal toxins and increase excretion of intestinal toxins. The present study was to investigate whether a combination of taurine and oat has an additive inhibitory effect on endotoxin release in a rat liver ischemia/reperfusion model. Our results showed that the combination of taurine (300mgkg(-1)d(-1)) and oat fiber (15gkg(-1)d(-1)) significantly reduced endotoxin levels in the portal vein by 36.3% when compared to the control group (0.168+/-0.035Eu/ml in the treatment group vs 0.264+/-0.058Eu/ml in the control group, P<0.01). The treatment of taurine (300mgkg(-1)d(-1)) and oat fiber (15gkg(-1)d(-1)) induced 21.5% and 18.4% reduction in endotoxin levels, respectively, when compared to the control group (P<0.05). We conclude that the combination of taurine and oat fiber achieved an additive inhibitory effect on intestinal endotoxin release, which might be an effective approach for the treatment of intestinal endotoxemia.

Synthesis and Application of a Novel Ligand for Affinity Chromatography Based Removal of Endotoxin from Antibodies

Endotoxin or lipopolysaccharide (LPS) contamination in proteins expressed by Gram-negative bacteria is a major drawback associated with protein expression. Endotoxin intoxication in humans and animals above a certain threshold level can result in a fatal immune response. Reduction in endotoxin levels is therefore essential before proteins can be used in in vivo studies or sold as pharmaceutical products. Affinity chromatography employing the peptide Polymyxin B (PMB) as an affinity ligand is one way in which endotoxin contamination has been addressed; this is, however, a costly process. We describe the synthesis of a novel affinity ligand based on the structure of the drug pentamidine, which can be applied effectively in endotoxin removal. The synthetic route to this ligand is straightforward and inexpensive, while the ligand can be readily immobilized onto activated sepharose beads. Thus, we demonstrate that these pentamidine affinity beads bind endotoxin/LPS with comparable capacity to PMB affinity systems, that the beads can be recycled efficiently and economically without loss of binding capacity, and application of the functionalized beads for endotoxin removal in an authentic contaminated antibody sample.

Peritoneal taurolidine lavage in children with localised peritonitis due to appendicitis

Despite aggressive surgical treatment, rational antibiotic therapy, and modern intensive care, generalised peritonitis remains a major threat in the paediatric age group. Several adjuvant strategies such as peritoneal saline lavage and peritoneal drainage have been utilised. Taurolidine, derived from the amino acid taurine, has bactericidic, antiendotoxic, and antiinflammatory properties. It has been introduced previously for intraoperative peritoneal lavage in treating peritonitis in adults. The aim of our study was to evaluate the effect of peritoneal taurolidine lavage on the clinical course and serological inflammation markers in children with perforated appendicitis and localised peritonitis. A series of 27 children presenting with appendicitis between January 1999 and July 2001 were included in the study after parental informed consent. All patients underwent open appendectomy. Taurolidine peritoneal lavage was applied in 15 randomly selected children (eight girls and seven boys; mean age 10 years and 10 months). Twelve children received saline peritoneal lavage and served as the control group (six girls and six boys; mean age 9 years and 7 months). Blood was taken preoperatively and on postoperative days 1, 3, 7, and 14. Full blood cell count, C-reactive protein, endotoxin, interleukin-1, interleukin-6, soluble interleukin-2 receptor, tumour necrosis factor alpha, and procalcitonin were investigated to evaluate the serological course of inflammation. Both groups initially presented with severe inflammation as evidenced clinically and serologically. The clinical postoperative course was uneventful in 13/15 patients in the treatment group and 10/12 patients in the control group. The remaining patients presented complications: intraperitoneal abscess or early postoperative bowel obstruction. With regard to the serological inflammatory parameters, no significant differences were found between the two groups except for the soluble interleukin-2-receptor on the 7th postoperative day. In conclusion, the expected reduction of endotoxin levels and inflammatory activity in the treatment group was not evident. A significant advantage of adjuvant peritoneal taurolidine lavage in the surgical therapy of children with localised peritonitis due to appendicitis could not be shown in our study.

Removal of endotoxin from recombinant protein preparations.

To develop an effective method to remove endotoxin from large scale E. coli recombinant protein purifications. Triton X-114 phase separation, affinity chromatography utilizing immobilized polymyxin B or immobilized histidine, were used to remove endotoxin from purified preparations of recombinant CK-BB, CK-MB, CK-MM, myoglobin, and cardiac troponin I. Endotoxin levels were measured by a Limulus Amebocyte Lysate gel-clot assay. The immunoactivity of these protein preparations was determined by BIAcore analysis using a panel of in-house generated monoclonal antibodies and by a Stratus Fluorometric Analyzer. In the case of troponin I, the BIAcore was also utilized to measure troponin C interactions. Phase separation with Triton X-114 was the most effective method in reducing the amount of endotoxin present in the protein preparations compared to either polymyxin B or histidine affinity chromatography. With Triton X-114, the reduction in endotoxin levels was greater than 99% and recovery of the proteins after endotoxin removal was greater than 90%. All three procedures for removing endotoxin had no deleterious effects on the immunoactivity of majority proteins when tested with a panel of monoclonal antibodies. Troponin I also retained its ability to bind to troponin C in the presence of Ca2+. Recombinant CK-BB and CK-MM which were expressed in the soluble fraction of E. coli cell lysates, contained significantly higher endotoxin levels than recombinant CK-MB, myoglobin and cardiac troponin I which were expressed in the form of inclusion bodies. Of the three methods tested, Triton X-114 phase separation was the most effective way of removing endotoxin from recombinant proteins.

Immunosuppressive effects of endotoxins and bile acids in vivo in the rat

Cell-mediated immunity is impaired during cholestasis. The aim of this study was to evaluate in vivo the effects on this immune defect of high serum levels of endotoxin and bile acids. Heterotopic cardiac allotransplantations were performed in the DA/Lewis rat combination. Cholestasis, induced by ligation/section of the common bile duct, was responsible for a significant delay in the rejection time (16 +/- 0.5 vs. 7.1 +/- 0.4 days in controls, P < 0.01). Elimination of Gram-negative intestinal bacteria from cholestatic rats by a vancocin/colimycin/tobramycin (VCT) mixture induced a significant reduction in endotoxin levels and a reduction in rejection times (9.5 +/- 1.0 days, P < 0.01) that remained, however, significantly longer than those of controls (P < 0.05). Oral administration of chenodeoxycholic acid in non-cholestatic rats significantly enhanced the serum concentration of total bile acids (60.6 +/- 15.3 mumol L(-1) vs. 17.4 +/- 1.9 mol L(-1) in controls, P < 0.01) and postponed allograft rejection (10.7 +/- 0.6 days, P < 0.01 vs. controls). These data suggest that increased endotoxin level and serum bile acid concentration may play a role in the immunosuppressive effect of cholestasis.

Control of Endotoxemia in Burn Patients by Use of Polymyxin B

A group of patients with severe burns were entered into two sequential prospective randomized trials for reduction of endotoxemia by the use of intravenous polymyxin B. The first group underwent polymyxin administration during the first week after burn injury in a bell-shaped dosage form constructed to resemble the level of endotoxemia as previously documented. This group showed a statistically highly significant reduction in endotoxin levels and a suggestive, but not statistically significant, reduction in wound infection and mortality in the treated group compared with controls. The second group of patients underwent treatment with perioperative polymyxin B given in conjunction with an excisional procedure of the burn wound. In this group, polymyxin B also accomplished a reduction in endotoxemia from preoperative to postoperative cases, but there was no significant reduction in clinical complication rate or mortality. In the dosages used, polymyxin B is nontoxic and promises to be a useful part of the surgeon's armamentarium in dealing with severe complications of gram-negative sepsis.

Reduction of endotoxin levels in influenza virus vaccines by barium sulfate adsorption-elution.

The level of endotoxin in influenza virus vaccine lots was reduced 10- to 20-fold after barium sulfate adsorption-elution. The amount of viral antigen lost was negligible.