Soybean isoflavones modulate gut microbiota to benefit the health weight and metabolism.

Soybean isoflavones (SIs) are widely found in food and herbal medicines. Although the pharmacological activities of SIs have been widely reported, their effects on the intestinal microecology of normal hosts have received little attention. Five-week-old Kunming (KM) mice were administered SIs (10 mg/kg/day) for 15 days. Food intake, body weight, and digestive enzyme activity were measured. Small intestine microbiota, including lumen-associated bacteria (LAB) and mucosa-associated bacteria (MAB), were analyzed using 16S ribosomal ribonucleic acid (16S rRNA) gene sequencing. Short-chain fatty acids (SCFAs) were analyzed using gas chromatography-mass spectrometry (GC-MS). The results showed that the mice that consuming SIs showed a higher food intake but a lower body weight gain rate than that of normal mice. Sucrase, cellulase, and amylase activities reduced, while protease activity increased after SIs intervention. Moreover, SIs increased the intestinal bacterial diversity in both LAB and MAB of normal mice. The composition of LAB was more sensitive to SIs than those of MAB. Lactobacillus, Adlercreutzia, Coprococcus, Ruminococcus, Butyricicoccus, and Desulfovibrio were the differential bacteria among the LAB of mice treated with SIs. In addition, acetic acid, valeric acid, isobutyric acid, isovaleric acid, and caproic acid decreased, while butyric acid and propionic acid increased in the mice treated with SIs. Taken together, SIs are beneficial for weight control, even in short-term interventions. The specific mechanism is related to regulating the gut microbiota, changing digestive enzyme activities, and further affecting carbohydrate absorption and metabolism.

Interaction of Antipsychotic Drugs with Sucrase, Kinetics and Structural Study.

BACKGROUND: In patients with the Congenital Sucrase-Isomaltase Deficiency (CSID), who lack intestinal sucrase-isomaltase enzyme, a suspension of yeast sucrase is applied as a drug to compensate the enzyme deficiency. While antipsychotic drugs are used for the treatment of schizophrenia, administering multiple drugs at the same time may counteract each other. METHODS: In this study, the interaction between trifluoperazine and haloperidol as antipsychotic drugs on oral drug yeast sucrase was investigated. In this regard, the kinetic parameters of enzyme were determined in the presence or absence of the drugs. The kinetic parameters of the drugs such as Ki and IC50 were also calculated. Lineweaver - Burk plot was used to reveal the type of inhibition. RESULTS: The results showed that both drugs could reduce sucrase activity and decrease the Vmax of the enzyme by non-competitive inhibition. The IC50 and Ki values of the drugs were determined to be 0.7 and 0.068 mM and 0.45 and 0.063 mM for haloperidol and trifluoperazine, respectively. The results suggested that trifluoperazine binds to the enzyme with higher affinity than haloperidol. Fluorescence measurement was used for conformational investigations of the drugs and sucrase interaction. It was shown that the drugs bind to free enzyme and enzyme-substrate complex which are accompanied with hyperchromicity. This suggests that tryptophan residues of the enzyme transferred to hydrophobic medium after binding of the drugs to the enzyme. CONCLUSION: The finding of this research revealed that both trifluoperazine and haloperidol could inhibit sucrase in non-competitive manner. The kinetic parameters and conformational changes due to binding of trifluoperazine to the enzyme were different from that of haloperidol.

Anti-hyperglycemic activity of an aqueous extract from flower buds of Cleistocalyx operculatus (Roxb.) Merr and Perry.

A screening of 5 plants used for making drinks in Vietnam revealed a Cleistocalyx operculatus (Roxb.) Merr and Perry flower bud extract to have the highest inhibitory activity against the alpha-glucosidase enzyme. The anti-hyperglycemic effects of an aqueous extract from flower buds of Cleistocalyx operculatus (CO), a commonly used material for drink preparation in Vietnam, were therefore investigated in vitro and in vivo. In vitro, the CO extract inhibited the rat-intestinal maltase and sucrase activities, with IC50 values of 0.70 and 0.47 mg/ml, respectively. These values are lower than those for a guava leaf extract (GE; IC50 0.97 and 1.28 mg/ml, respectively). Postprandial blood glucose testing of normal mice and STZ-induced diabetic rats by maltose loading (2 g/kg body weight (bw)) showed that the blood glucose reduction with CO (500 mg/kg bw) was slightly less than that with acarbose (25 mg/kg bw) but was more potent than that with GE (500 mg/kg bw). In an 8-week experiment, the blood glucose level of STZ diabetic rats treated with 500 mg of CO/kg bw/day was markedly decreased in comparison with that of non-treated diabetic rats. Consequently, CO is considered to be a promising material for preventing and treating diabetes.

Isolation of human small intestinal brush border membranes using polyethylene glycol and effect of exposure to various oxidants in vitro.

This study presents a method of brush border membrane (BBM) preparation from the human small intestine using polyethylene glycol (PEG) precipitation and also looks at the effect of in vitro oxidant exposure on structural and functional alterations in the membrane. Isolated BBM were relatively pure as judged by 10- to 14-fold enrichment of marker enzymes with less than 1% contamination by other subcellular organelles. These membranes showed uphill transport of glucose and lipid analysis showed a cholesterol-phospholipid (C/P) ratio of 1.19. Isolated BBM were found to be susceptible to superoxide generated by xanthine oxidase (XO), resulting in lipid and protein oxidation along with altered glucose uptake. Superoxide exposure also resulted in phospholipid alterations, especially generation of lyso phospholipids. These changes were prevented by inhibiting XO by allopurinol or scavenging superoxide by superoxide dismutase (SOD). Other oxidants studied did not have significant affect on these membranes. These studies suggest that PEG can be used for preparation of BBM from the human small intestine and these membranes undergo structural and functional alterations on exposure to superoxide.

Interactions of the regulatory ligands Mg2+ and MgATP2- with the renal plasma membrane Ca(2+)-ATPase: effects of osmolytes that stabilize or destabilize protein structure

In this report we analyze the kinetics of activation of the plasma membrane Ca(2+)-ATPase from kidney proximal tubules by the regulatory ligands Mg2+ and MgATP2-, and we examine modifications in the effects of these ligands that are promoted by organic solutes of natural occurrence that stabilize or destabilize protein structure and function. The solutes tested were trimethylamine-N-oxide (TMA-O), sucrose and urea. TMA-O and sucrose were chosen as representative of the different methylamines and polyols, respectively, that accumulate in living organisms. The results lead to the conclusion that free Mg2+ and the MgATP2- complex both activate the rate-determining E2-->E1 transition during the catalytic cycle of the enzyme, by binding to nonidentical and independent regulatory sites. They also indicate that TMA-O, sucrose and urea not only promote global modifications in the enzyme structure, but also modify specific interactions of the ligands Mg2+ and MgATP2- at their regulatory sites

Teratocarcinoma stem cells have a cell surface carbohydrate-binding component implicated in cell-cell adhesion.

Teratocarcinoma stem cells maintained in the undifferentiated state express a carbohydrate-binding component that recognizes oligomannosyl residues. This cell surface molecule is detected by a rosetta assay in which the stem cells form rosettes with glutaraldehyde-fixed trypsinized rabbit erythrocytes. Addition of simple sugars to the assay mixture has little effect, but rosette formation is inhibited by a series of mannose-rich glycoproteins (yeast invertase, yeast mannans and horseradish peroxidase). Periodate oxidation eliminates the inhibitory activity of invertase whereas pronase digestion has little effect, indicating that carbohydrate moieties are essential for inhibition. Invertase and its glycopeptide derivatives also inhibit the reaggregation of dispersed stem cells and promote the dissociation of preformed aggregates. These results suggest that intercellular adhesion of teratocarcinoma stem cels may be the consequence of the interaction of a lectin-like component detected in the rosette assay with a complementary oligosaccharide receptor on adjacent cells.

[Studies on the effects of intravenous administration of glucose, fructose, invertose and sorbitol on various blood constituents of blood plasma (monosaccharides, insulin, lactate, pyruvate and free fatty acids as well as glutamate-oxaloacetate transaminase) in the horse]. / Untersuchungen über den Einfluss der intravenösen Verabreichung von Lösungen der Glukose, der Fruktose, des Invertzuckers und des Sorbits auf verschiedene Bestandteile des Blutes bzw. Blutplasmas (Monosaccharide, Insulin, Laktat, Pyruvat, freie Fettsäuren und Glutamat-Oxalazetat-Transaminase) vom Pferd.

Horses were examined for the behaviour of various blood constituents prior to and following infusions of solutions of glucose, fructose, invertose, and sorbitol. Infusion of 0.5 g/kg live weight glucose to six horses was followed by half-life variation between eleven and 23 minutes. Subsequent infusion of invertose to the same animals usually caused prolongation of glucose half-life. Half-life values were between 17 and 33 minutes for fructose and between 21 and 80 minutes for glucose. Infusion of 0.5 g/kg live weight fructose to two horses was followed by half-life values between 17 and 18 minutes, while the half-life values of sugar alcohol were 16, 16, 27, and 29 minutes in four horses who had received sorbitol. Sugar or sorbitol infusion was not followed by substantive change of lactate and pyruvate concentrations in the blood or free fatty acids in the blood plasma or GOT activity. The rise of insulin in the blood plasma was differentiated. Invertose and sorbitol solutions, consequently, can be recommended for application to horses.

Relative effects of sucrolytic enzymes in human dental plaque.

The relative effects in human dental plaque material from the three main extracellular sucrolytic enzymes from bacterial origin, invertase, dextransucrase and levansucrase, have been investigated by means of quantitative determination of products with sucrose as the substrate. Twenty young men having carious lesions and harboring plaque material on the tooth surfaces, were selected. One gram (wet weight) of plaque material was obtained and divided in five samples, 0.2 g each, for different investigations and controls. Twice as much fructan as glucan was found in plaque. Invertase activity was found to dominate sucrolysis within plaque with 99.67% of the total activity.

Relationship between cell-bound dextransucrase and the agglutination of Streptococcus mutans.

Dextran-induced agglutination of Streptococcus mutans cells is independent of cell-bound dextransucrase activity. Toluene extraction or the presence of Hg2+ or Cu2+ markedly decreased or completely abolished cell-bound dextransucrase activity without adversely affecting dextran-induced cell agglutination. Cells treated by heating at 100 C until cell-bound dextransucrase was completely inactivated continued to agglutinate when induced by dextran-induced cell agglutination resulted from cell treatment with trypsin and several other enzymes, as well as from ethylenediaminetetraacetic acid treatment, without a corresponding loss of cell-bound dextransucrase activity. Cells possessed a greater avidity for branched dextrans of low molecular weight than for linear dextrans of the same weight, indicating that size alone does not determine the efficiency of dextran as an inducer of agglutination. Divalent metal ions were required for both sucrose- and dextran-induced agglutination of S. mutans K1-R cells. Although normal cells of strain 6715-49 did not appear to require divalent cations for agglutination, heat- and ethlyenediaminetetraacetic acid-treated cells specifically required Ca2+. The role of Ca2+ in cell agglutination may be either to activate the cell-surface dextran receptor or to form specific intercellular Ca2+ bridges.