The food processing contaminant glyoxal promotes tumour growth in the multiple intestinal neoplasia (Min) mouse model

Glyoxal

The Expert Panel for Cosmetic Ingredient Safety reviewed information that has become available since their year 2000 assessment, along with updated information regarding product types, and frequency and concentrations of use, and reaffirmed their original conclusion that Glyoxal is safe for use in products intended to be applied to the nail at concentrations ≤1.25% and that the available data are insufficient to support the safety for other uses.

A fast and efficient method for the analysis of α-dicarbonyl compounds in aqueous solutions: Development and application

Among the highly oxygenated species formed in situ in the atmosphere, α-dicarbonyl compounds are the most reactive species, thus contributing to the formation of secondary organic aerosols that affect both air quality and climate. They are ubiquitous in the atmosphere and are easily transferred to the atmospheric aqueous phase due to their high solubility. In addition, α-dicarbonyl compounds are toxic compounds found in food in biochemistry studies as they can be produced endogenously through various pathways and exogenously through the Maillard reaction. In this work, we take advantage of the high reactivity of α-dicarbonyl compounds in alkaline solutions (intramolecular Cannizzaro reaction) to develop an analytical method based on high performance ion chromatography. This fast and efficient method is suitable for glyoxal, methylglyoxal and phenylglyoxal which are detected as glycolate, lactate and mandelate anions respectively, with 100% conversion at pH > 12 and room temperature for exposure times to hydroxide ranging from 5 min to 4 h. Diacetyl is detected as 2,4-dihydroxy-2,4-dimethyl-5-oxohexanoate due to a base-catalysed aldol reaction that occurs before the Cannizzaro reaction. The analytical method is successfully applied to monitor glyoxal consumption during aqueous phase HO∙-oxidation, an atmospherically relevant reaction using concentrations that can be observed in fog and cloud water. The method also reveals potential analytical artifacts that can occur in the use of ion chromatography for α-hydroxy carboxylates measurements in complex matrices due to α-dicarbonyl conversion during the analysis time. An estimation of the artifact is given for each of the studied α-hydroxy carboxylates. Other polyfunctional and pH-sensitive compounds that are potentially present in environmental samples (such as nitrooxycarbonyls) can also be converted into α-hydroxy carboxylates and/or nitrite ions within the HPIC run. This shows the need for complementary analytical measurements when complex matrices are studied.

Biochemical Reactions and Their Biological Contributions in Honey

Honey is known for its content of biomolecules, such as enzymes. The enzymes of honey originate from bees, plant nectars, secretions or excretions of plant-sucking insects, or from microorganisms such as yeasts. Honey can be characterized by enzyme-catalyzed and non-enzymatic reactions. Notable examples of enzyme-catalyzed reactions are the production of hydrogen peroxide through glucose oxidase activity and the conversion of hydrogen peroxide to water and oxygen by catalase enzymes. Production of hydroxymethylfurfural (HMF) from glucose or fructose is an example of non-enzymatic reactions in honey.

Glyoxal damages human aortic endothelial cells by perturbing the glutathione, mitochondrial membrane potential, and mitogen-activated protein kinase pathways

Background

Exposure to glyoxal, the smallest dialdehyde, is associated with several diseases; humans are routinely exposed to glyoxal because of its ubiquitous presence in foods and the environment. The aim of this study was to examine the damage caused by glyoxal in human aortic endothelial cells.

Methods

Cell survival assays and quantitative fluorescence assays were performed to measure DNA damage; oxidative stress was detected by colorimetric assays and quantitative fluorescence, and the mitogen-activated protein kinase pathways were assessed using western blotting.

Results

Exposure to glyoxal was found to be linked to abnormal glutathione activity, the collapse of mitochondrial membrane potential, and the activation of mitogen-activated protein kinase pathways. However, DNA damage and thioredoxin oxidation were not induced by dialdehydes.

Conclusions

Intracellular glutathione, members of the mitogen-activated protein kinase pathways, and the mitochondrial membrane potential are all critical targets of glyoxal. These findings provide novel insights into the molecular mechanisms perturbed by glyoxal, and may facilitate the development of new therapeutics and diagnostic markers for cardiovascular diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02418-3.

In vitro evaluation of anti-methylglyoxal/glyoxal activity of three phytosterols using glycated bovine serum albumin models

Reactive intermediate dicarbonyls, such as methylglyoxal (MGO) and glyoxal (GO), have received extensive attention recently due to their high reactivity and capability to form advanced glycation end products (AGEs) in foods, which have been implicated in the progression of age-related complaints. We aimed to investigate the effects of three structurally different phytosterols (PS), including stigmasterol (SS), β-sitosterol (βS), and γ-oryzanol (γO), on AGEs-formation by measuring their anti-GO/MGO activity. The glycoxidation-based products, SDS-PAGE intensity, free lysine, protein thiols, fluorescence microscopy clicks, scavenging of dicarbonyl activity, and protein aggregation in bovine serum albumin (BSA) models were therefore measured. The results showed that PS could strongly inhibit fluorescent-AGEs, lysine residues, intermediate di-carbonyls, beside their disaggregation effects in a dose and structure dependent manner. Additionally, γ-oryzanol strongly inhibited AGEs more than the other PS, mostly due to its distinctive structure. Our results will provide a new foundation for development of different structure of PS as natural AGEs-inhibitors.

DNA Adducts as Biomarkers To Predict, Prevent, and Diagnose Disease-Application of Analytical Chemistry to Clinical Investigations

Characterization of the chemistry, structure, formation, and metabolism of DNA adducts has been one of the most significant contributions to the field of chemical toxicology. This work provides the foundation to develop analytical methods to measure DNA adducts, define their relationship to disease, and establish clinical tests. Monitoring exposure to environmental and endogenous toxicants can predict, diagnose, and track disease as well as guide therapeutic treatment. DNA adducts are one of the most promising biomarkers of toxicant exposure owing to their stability, appearance in numerous biological matrices, and characteristic analytical properties. In addition, DNA adducts can induce mutations to drive disease onset and progression and can serve as surrogate markers of chemical exposure. In this perspective, we highlight significant advances made within the past decade regarding DNA adduct quantitation using mass spectrometry. We hope to expose a broader audience to this field and encourage analytical chemistry laboratories to explore how specific adducts may be related to various pathologies. One of the limiting factors in developing clinical tests to measure DNA adducts is cohort size; ideally, the cohort would allow for model development and then testing of the model to the remaining cohort. The goals of this perspective article are to (1) provide a summary of analyte levels measured using state-of-the-art analytical methods, (2) foster collaboration, and (3) highlight areas in need of further investigation.

The dark face of fructose as a tumor promoter

Fructose, an essential biomolecule and it is a major ingredient of the modern diet across the globe. Excess consumption of fructose may be a key driver of many serious diseases such as obesity, heart diseases, type 2 diabetes and cancer. Understanding the metabolism of fructose, molecular mechanisms of its toxic nature will aid in the treatment of various diseases including cancer.

Food-derived 1,2-dicarbonyl compounds and their role in diseases

Reactive 1,2-dicarbonyl compounds (DCs) are generated from carbohydrates during food processing and storage and under physiological conditions. In the recent decades, much knowledge has been gained concerning the chemical formation pathways and the role of DCs in food and physiological systems. DCs are formed mainly by dehydration and redox reactions and have a strong impact on the palatability of food, because they participate in aroma and color formation. However, they are precursors of advanced glycation end products (AGEs), and cytotoxic effects of several DCs have been reported. The most abundant DCs in food are 3-deoxyglucosone, 3-deoxygalactosone, and glucosone, predominating over methylglyoxal, glyoxal, and 3,4-dideoxyglucosone-3-ene. The availability for absorption of individual DCs is influenced by the release from the food matrix during digestion and by their reactivity towards constituents of intestinal fluids. Some recent works suggest formation of DCs from dietary sugars after their absorption, and others indicate that certain food constituents may scavenge endogenously formed DCs. First works on the interplay between dietary DCs and diseases reveal an ambiguous role of the compounds. Cancer-promoting but also anticancer effects were ascribed to methylglyoxal. Further work is still needed to elucidate the reactions of DCs during intestinal digestion and pathophysiological effects of dietary DCs at doses taken up with food and in "real" food matrices in disease states such as diabetes, uremia, and cancer.

Effects of Sodium Chloride, Potassium Chloride, and Calcium Chloride on the Formation of α-Dicarbonyl Compounds and Furfurals and the Development of Browning in Cookies during Baking

Effects of NaCl, KCl, CaCl₂, NaHCO₃, and NH₄HCO₃ on the formation of glucosone, 1-deoxyglucosone, 3-deoxyglucosone, glyoxal, methylglyoxal, diacetyl, 5-hydroxymethyl-2-furfural, and 2-furfural and browning were investigated in cookies. The presence of 1.5% NaCl, 1% KCl, and 1% CaCl₂ on flour basis had no effect on α-dicarbonyl compounds, except 1-deoxyglucosone increased in the presence of KCl and CaCl₂. The increase in 5-hydroxymethyl-2-furfural formation in the presence of NaCl, KCl, and CaCl₂ did not relate to 3-deoxyglucosone formation and pH changes. NaCl, KCl, and CaCl₂ increased browning in cookies. Model reaction systems indicated that NaCl, KCl, and CaCl₂ enhance browning by increasing furfurals in caramelization. NaCl, KCl, and CaCl₂ decreased browning intensity in a heated glucose-glycine system. Use of CaCl₂ in cookies may considerably increase furfurals but not α-dicarbonyl compounds. Sodium reduction can be obtained by replacement with potassium without sacrificing the desired consequences of caramelization in sugar-rich baked goods.