Net charge affects morphology and visual properties of ovalbumin aggregates

The effect of ovalbumin net charge on aggregate morphology and visual properties was investigated using chromatography, electrophoresis, electron microscopy, and turbidity measurements. A range of differently charged ovalbumin variants (net charge ranging from -1 to -26 at pH 7) was produced using chemical engineering. With increasing net charge...

Human cytochrome P450 enzymes of importance for the bioactivation of methyleugenol to the proximate carcinogen 1′-hydroxymethyleugenol

In vitro studies were performed to elucidate the human cytochrome P450 enzymes involved in the bioactivation of methyleugenol to its proximate carcinogen 1′-hydroxymethyleugenol. Incubations with Supersomes, expressing individual P450 enzymes to a high level, revealed that P450 1A2, 2A6, 2C9, 2C19, and 2D6 are intrinsically able to 1′...

Digestibility of resistant starch containing preparations using two in vitro models

Background: Resistant starch (RS) is known for potential health benefits in the human colon. To investigate these positive effects it is important to be able to predict the amount, and the structure of starch reaching the large intestine. Aim of the study: The aim of this study was to compare two different in vitro models simulating the...

D-Tagatose increases butyrate production by the colonic microbiota in healthy men and women

D-Tagatose is partly absorbed in the stomach and small intestine. Most of it is fermented by the large intestinal microbiota. The effect of D-tagatose on the composition of the microbiota and production of short chain fatty acids (SCFAs) was studied in vivo and in vitro. Gastrointestinal (GI) complaints were also studied. The in vivo study was...

Advanced glycation end product ligands for the receptor for advanced glycation end products: Biochemical characterization and formation kinetics

Advanced glycation end products (AGEs) accumulate with age and at an accelerated rate in diabetes. AGEs bind cell-surface receptors including the receptor for advanced glycation end products (RAGE). The dependence of RAGE binding on specific biochemical characteristics of AGEs is currently unknown. Using standardized procedures and a variety of...

The role of cyclooxygenase in n-6 and n-3 polyunsaturated fatty acid mediated effects on cell proliferation, PGE2 synthesis and cytotoxicity in human colorectal carcinoma cell lines

This study was conducted to investigate the role of the enzyme cyclooxygenase (COX) and its prostaglandin product PGE2 in n-6 and n-3 polyunsaturated fatty acid (PUFA)-mediated effects on cellular proliferation of two human colorectal carcinoma cell lines. The long chain PUFAs eicosapentaenoic acid (EPA; 20:5n-3) and arachidonic acid (AA; 20:4n...

Biosensors and multiple mycotoxin analysis

An immunochemical biosensor assay for the detection of multiple mycotoxins in a sample is described.The inhibition assay is designed to measure four different mycotoxins in a single measurement, following extraction, sample clean-up and incubation with an appropriate cocktail of anti-mycotoxin antibodies.The different mycotoxins could be...

Inhibition of human glutathione S-transferase P1-1 by the flavonoid quercetin

In the present study, the inhibition of human glutathione S-transferase P1-1 (GSTP1-1) by the flavonoid quercetin has been investigated. The results show a time- and concentration-dependent inhibition of GSTP1-1 by quercetin. GSTP1-1 activity is completely inhibited upon 1 h incubation with 100 μM quercetin or 2 h incubation with 25 μM quercetin...

Recombinant Saccharomyces cerevisiae expressing P450 in artificial digestive systems: A model for biodetoxication in the human digestive environment

The use of genetically engineered microorganisms such as bacteria or yeasts as live vehicles to carry out bioconversion directly in the digestive environment is an important challenge for the development of innovative biodrugs. A system that mimics the human gastrointestinal tract was combined with a computer simulation to evaluate the survival...

Hyperoxia and local organ blood flow in the developing chick embryo

1. Hyperoxia can cause local vasoconstriction in adult animal organs as a protective mechanism against hyperoxia-induced toxicity. It is not known at what time during development this vasoconstrictor capacity is present. Therefore, we measured the cardiac output (GO) distribution in different organs during a period of acute hyperoxia (100% O2)...

Comparison of five incubation systems for rat liver slices using functional and viability parameters

Precision-cut liver slices are presently used for various research objects, e.g. to study metabolism, transport, and toxicity of xenobiotics. Various incubation systems are presently employed, but a systematic comparison between these incubation systems with respect to preservation of slice function has not been performed yet. Therefore, we...