Effects of 1,5-anhydroglucitol on postprandial blood glucose and insulin levels and hydrogen excretion in rats and healthy humans.

The inhibition by 1,5-anhydro-d-glucitol (1,5-AG) was determined on disaccharidases of rats and humans. Then, the metabolism and fate of 1,5-AG was investigated in rats and humans. Although 1,5-AG inhibited about 50 % of sucrase activity in rat small intestine, the inhibition was less than half of d-sorbose. 1,5-AG strongly inhibited trehalase and lactase, whereas d-sorbose inhibited them very weakly. 1,5-AG noncompetitively inhibited sucrase. The inhibition of 1,5-AG on sucrase and maltase was similar between humans and rats. 1,5-AG in serum increased 30 min after oral administration of 1,5-AG (600 mg) in rats, and mostly 100 % of 1,5-AG was excreted into the urine 24 h after administration. 1,5-AG in serum showed a peak 30 min after ingestion of 1,5-AG (20 g) by healthy subjects, and decreased gradually over 180 min. About 60 % of 1,5-AG was excreted into the urine for 9 h following ingestion. Hydrogen was scarcely excreted in both rats and humans 24 h after administration of 1,5-AG. Furthermore, 1,5-AG significantly suppressed the blood glucose elevation, and hydrogen excretion was increased following the simultaneous ingestion of sucrose and 1,5-AG in healthy subjects. 1,5-AG also significantly suppressed the blood glucose elevation following the simultaneous ingestion of glucose and 1,5-AG; however, hydrogen excretion was negligible. The available energy of 1,5-AG, which is absorbed readily from the small intestine and excreted quickly into the urine, is 0 kJ/g (0 kcal/g). Furthermore, 1,5-AG might suppress the blood glucose elevation through the inhibition of sucrase, as well as intestinal glucose absorption.

Prognostic value of pretreatment inflammatory biomarkers in patients with laryngeal cancer.

OBJECTIVES: The systemic inflammatory response is strongly involved in the progression of malignant tumors, and it is useful for predicting survival time and determining therapeutic effects. The inflammatory biomarkers, neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR) are used to assess post-treatment survival and recurrence in various malignant tumors.(Walsh et al., 2005; Burt et al., 2011; Smith et al., 2009) 1,2,3 These indicators may be effective as predictive markers for head and neck malignancies. METHODS: The participants were 125 glottic laryngeal and supraglottic cancer cases who received primary treatment in our department from 2010 to 2016. The NLR, LMR, and PLR for each patient were calculated in addition to the association with overall survival (OS) rate, disease-specific survival (DSS) rate, and laryngeal preservation rate for tumor location, T and N classification, TNM stage classification, treatment, and smoking. We investigated whether inflammatory biomarkers are useful for predicting prognosis. RESULTS: The cutoff values for NLR, LMR, and PLR on the ROC curve were 1.88, 5.57, and 108, respectively. Multivariate analysis with LMR 5.57 as the cutoff value showed significant differences in OS, DSS, and laryngeal preservation. However, setting the cutoff values for NLR 1.88 and PLR 108 showed significant differences only in OS and laryngeal preservation. CONCLUSION: LMR may be a total survival predictor of laryngeal cancer, including OS, DSS, and laryngeal preservation.

Impact of IL-17-producing γδ T cells on chronic otitis media induced by nontypeable Haemophilus influenzae in a mouse model.

Nontypeable Haemophilus influenzae (NTHi) is considered a major pathogen underlying middle ear infection. This study aimed to investigate the impact of IL-17 on chronic otitis media (COM) induced by NTHi in mice. NTHi was inoculated into the tympanic bulla with eustachian tubal obstruction. Middle ear effusions (MEEs) and tissues were collected on days 3, 14, and at 1, 2, and 6 months after injection. The expression of interleukin-17A (IL-17A) in MEEs was significantly elevated compared to that in the control group at the translational and transcriptional levels during the experiments. The quantities of IL-17-producing γδ T cells were significantly increased compared to that in the control group during COM, but that of Th17 cells did not. Depletion of γδ T cells by anti-γδ T-cell receptor (TCR) monoclonal antibody (mAb) administration significantly decreased the bacteria counts and the concentrations of IL-1ß, IL-6, IL-17A, TNF-α, and IL-10 in MEEs. Our results suggest that IL-17 may play an important role in prolonging the inflammation in the middle ear in COM and that IL-17-producing γδ T cells may contribute to the exacerbated inflammatory response in the middle ear. In this study, anti-γδ TCR mAb administration was found to improve chronic middle ear inflammatory conditions.

In Vivo Metabolism of 1,5-Anhydro-d-fructose to 1,5-Anhydro-d-glucitol.

BACKGROUND/AIM: 1,5-Anhydro-d-fructose (1,5-AF, saccharide) and 1,5-anhydro-d-glucitol (1,5-AG) converted from 1,5-AF via the glycemic pathway have health benefits. However, this metabolism has not been sufficiently elucidated. To clarify the in vivo metabolism of 1,5-AF to 1,5-AG, porcine (blood kinetics) and human (urinary excretion) studies were conducted. MATERIALS AND METHODS: Microminipigs were administrated 1,5-AF orally or intravenously. Blood samples were obtained to analyse the kinetics of 1,5-AF and 1,5-AG. Urine samples were collected from human subjects who had orally ingested 1,5-AF, and the amounts of 1,5-AF and 1,5-AG excreted in the urine were analysed. RESULTS: In blood kinetics analysis, the time to the maximum concentration of 1,5-AF after intravenous administration was 0.5 h, whereas 1,5-AF was not observed after oral administration. The times to the maximum concentration of 1,5-AG after intravenous and oral administration were 1.5 h and 2 h, respectively. In urinary excretion, the concentration of 1,5-AG in urine rapidly increased after the administration of 1,5-AF, peaked at 2 h, whereas 1,5-AF was not detected. CONCLUSION: 1,5-AF was rapidly metabolized to 1.5-AG in vivo in swine and human.

Phase variation with altering phosphorylcholine expression of nontypeable Haemophilus influenzae affects bacteria clearance and mucosal immune response in the middle ear and nasopharynx.

OBJECTIVES: Nontypeable Haemophilus influenzae (NTHi) is a chief pathogen in both acute otitis media and otitis media with effusion. Phosphorylcholine (ChoP) is expressed on lipooligosaccharides, and ChoP has phase variation, which is related to its adhesion to and invasion of epithelial cells in the upper airway. However, little is known about the role of ChoP expression. We examined the kinetics of the mucosal clearance of NTHi from the nose and middle ear and the mucosal immune response to NTHi infection by comparing ChoP(+) and ChoP(-) strains in a mouse model of middle ear and nasal challenge. METHODS: Six-week-old male BALB/c mice were subjected to bacterial challenge in the middle ear and nasopharynx. Mice were inoculated with a suspension of a ChoP(+) strain or ChoP(-) strain of NTHi. On days 1, 3, and 7 after inoculation, the middle ear wash (MEW) and nasal wash (NW) were harvested from each group. The samples were used for bacterial counts and the supernatant was used to measure the level of cytokines and C-reactive protein (CRP). RESULTS: MEWs in the ChoP(+) strain group had significantly higher bacterial counts than those in the ChoP(-) strain group on day 1. However, bacteria were eradicated in the ChoP(+) strain group on day 7. NWs in the ChoP(+) strain group had higher bacterial counts than those in the ChoP(-) strain group during the experiment, however, there was no significant difference between the two strains. The levels of cytokines were significantly higher in the ChoP(-) strain group than in the ChoP(+) strain group in MEWs, but these cytokine levels were low in NWs. The CRP concentration in the ChoP(-) group was high on day 7 in the MEWs. In NWs, the CRP concentration was low in all groups during the experiment. CONCLUSION: ChoP expression of NTHi changes the organism susceptible to killing by CRP, and the ChoP(+) strain might be gradually eradicated from the middle ear via the CRP-complement cascade, but not from nasopharynx. Based on our findings, phase variation by altering Phosphorylcholine expression of nontypeable Haemophilus influenzae affects bacteria clearance and mucosal immune response in the middle ear and nasopharynx.

1,5-anhydro-D-fructose and its derivatives: biosynthesis, preparation and potential medical applications.

1,5-Anhydro-D-fructose (AF) was first found in fungi and red algae. It is produced by the degradation of glycogen, starch and maltosaccharides with α-1,4-glucan lyase (EC 4.2.2.13). In vivo, AF is metabolized to 1,5-anhydro-D-glucitol (AG), ascopyrone P (APP), microthecin and other derivatives via the anhydrofructose pathway. The genes coding for the enzymes in this pathway have been cloned, enabling the large-scale production of AF and related products in a cell-free reactor. The possible applications of these products in medicine have been evaluated using both in vitro and in vivo systems. Thus AF is a useful anticariogenic agent as it inhibits the growth of the oral pathogen Streptococcus mutans, impairing the production of plaque-forming polysaccharides and lactic acid. AF also shows anti-inflammatory and anticancer effects. AG is used as a diabetic marker for glycemic control. AG also stimulates insulin secretion in insulinoma cell lines. in vivo, APP has been shown to lengthen the life span of cancer-afflicted mice. It interferes with tumor growth and metastasis by its cidal effects on fast multiplying cells. Microthecin inhibits the growth of the human pathogen Pseudomonas aeruginosa PAO1, particularly under anaerobic conditions. The pharmaceutical usefulness of the other AF metabolites 1,5-anhydro-D-mannitol,1-deoxymannojirimycin, haliclonol, 5-epipentenomycin I, bissetone, palythazine, isopalythazine, and clavulazine remains to be investigated. In this review AF and its metabolites as the bioactive natural products for their pharmaceutical potentials are discussed.

Interaction Between Regulatory T Cells and Antibody-Producing B Cells for Immune Responses at the Upper Respiratory Mucosa Against Nontypeable Haemophilus influenzae: In Vitro Assay Model.

OBJECTIVES: The aim of this study was to investigate the effect of regulatory T cells (Tregs) on B-cell immune responses against outer membrane protein (OMP) from nontypeable Haemophilus influenzae (NTHi) in vitro, to clarify its exact mechanism from an immunologic standpoint. METHODS: Mice were vaccinated intranasally with OMP to induce OMP-specific immune responses in the nasal mucosa. Mononuclear cells (MNCs) were collected from the nasal mucosa, and Tregs and helper T (Th) cells were isolated separately from the spleens of those mice. Three different cell culture groups were allocated: MNCs cocultured with Tregs, MNCs cocultured with Th cells, and MNCs cultured alone. At 24 and 72 hours after cell culture, the concentrations of various cytokines and antibodies in culture supernatants were measured to assess the effects of Tregs and Th cells on B-cell responses. Cytokine levels and specific anti-OMP antibody levels in culture media were determined using enzyme-linked immunosorbent assay. CD69 or CD80 expression on B220-positive cells was detected using flow cytometric analysis. RESULTS: Th1 and Th2 cytokine concentrations were significantly elevated in the 3 groups incubated with OMP from 24 to 72 hours. Additionally, interleukin-10 levels were significantly higher in the Treg and Th groups than in the control group. Levels of OMP-specific immunoglobulin A did not differ significantly among the groups. The ratios of CD69+B220+ B2 cells were nearly the same in the 3 groups; however, the ratio of CD80+B220+ B2 cells was higher in the control group than in the Treg and Th groups during incubation. CONCLUSIONS: Tregs and Th cells did not affect OMP-specific immunoglobulin A production in this study. However, these cells may partially inhibit B-cell functions, such as T-cell activation. These inhibitory effects may be related to interleukin-10.

Enzymatic Synthesis of 1,5-Anhydro-4-O-ß-D-glucopyranosyl-D-fructose Using Cellobiose Phosphorylase and Its Spontaneous Decomposition via ß-Elimination.

Cellobiose phosphorylase from Cellvibrio gilvus was used to prepare 1,5-anhydro-4-O-ß-D-glucopyranosyl-D-fructose [ßGlc(1→4)AF] from 1,5-anhydro-D-fructose and α-D-glucose 1-phosphate. ßGlc(1→4)AF decomposed into D-glucose and ascopyrone T via ß-elimination. Higher pH and temperature caused faster decomposition. However, decomposition proceeded significantly even under mild conditions. For instance, the half-life of ßGlc(1→4)AF was 17 h at 30 °C and pH 7.0. Because ßGlc(1→4)AF is a mimic of cellulose, in which the C2 hydroxyl group is oxidized, such decomposition may occur in oxidized cellulose in nature. Here we propose a possible oxidizing pathway by which this occurs.

Preparation and reactivity of a novel disaccharide, glucosyl 1,5-anhydro-D-fructose (1,5-anhydro-3-O-alpha-glucopyranosyl-D-fructose).

A novel disaccharide, glucosyl 1,5-anhydro-D-fructose (1,5-anhydro-3-O-alpha-glucopyranosyl-D-fructose, GAF) was enzymatically prepared from 1,5-anhydro-D-fructose (1,5-AF) and cyclomaltoheptaose (beta-cyclodextrin). Cyclodextrin glucanotransferase transferred various sizes of maltooligosaccharide to 1,5-AF. Glucoamylase digested the maltooligosyl chain of the products to a glucosyl residue giving a final product, GAF. An NMR analysis of GAF elucidated that the glucose residue was linked to C-3 of the 1,5-AF residue with an ether linkage. Reactivity on the aminocarbonyl reaction of GAF with bovine serum albumin was lower than that of 1,5-AF, but was higher than that of glucose.

1,5-Anhydro-D-fructose: A natural antibiotic that inhibits the growth of gram-positive bacteria and microbial biofilm formation to prevent nosocomial infection.

Nosocomial infections caused by microbial opportunistic infections or microbial biofilms may occur during hospitalization and increase patient morbidity, mortality and health care costs. Artificial antibiotic agents were initially used to prevent infection; however, the high prevalence of nosocomial infections has resulted in their excessive use, which has led to microbial resistance to these agents. The increase in microbial resistance to antibiotics and the development of antibiotic agents may be the cause of the production of other microbial resistance. Thus, natural compounds that have no adverse side effects would be a preferred treatment modality. Recently, the monosaccharide 1,5-anhydro-D-fructose (1,5-AF), a natural plant compound derived from starch, has been found to have multifunctional properties, including antioxidant, antiplatelet aggregation by thrombin and anti-inflammatory activities. The results of the present study demonstrate that 1,5-AF suppressed the growth of coagulase-negative staphylococci on the hands as well as the growth of Staphylococcus epidermidis, which is a cause of opportunistic infections. Furthermore, 1,5-AF suppressed biofilm formation by the methicillin-resistant Staphylococcus aureus. In conclusion, 1,5-AF is a natural compound that may be effective in preventing nosocomial infections, without causing adverse side effects.