Yeast Saccharomyces cerevisiae devoid of Cu,Zn-superoxide dismutase as a cellular model to study acrylamide toxicity

Protective effect of Aronia melanocarpa juice against acrylamide-induced cellular toxicity

Acrylamide (AA) a widely used industrial chemical is also formed during food processing by the Maillard reaction, which makes its exposure to humans almost unavoidable. In this study, we used Schizosaccharomyces pombe as a model organism to investigate AA toxicity (10 or 20 mM concentration) in eukaryotes. In S. pombe, AA delays cell growth causes oxidative stress by enhancement of ROS production and triggers excitement of the antioxidant defence system resulting in the division arrest. Aronia fruit contains a variety of health-promoting substances with considerable antioxidant potential. Therefore, Aronia juice supplementation was tested to evaluate its protective effect against AA-derived perturbations of the organism. Cell treatment with several Aronia juice concentrations ranging from 0 to 2% revealed the best protective effect of 1 or 2% Aronia juice solutions. Both chosen Aronia juice concentrations alleviated AA toxicity through the improvement of the antioxidant cell capacity and metabolic activity by their strong ROS scavenging property. Efficiency of Aronia juice cell protection is dose dependent as the 2% solution led to significantly higher cellular defence compared with 1%. Due to the high similarity of biological processes of S. pombe with higher eukaryotes, the protective effect of Aronia juice against AA toxicity might also apply to higher organisms.

Acrylamide-Derived Ionome, Metabolic, and Cell Cycle Alterations Are Alleviated by Ascorbic Acid in the Fission Yeast

Acrylamide (AA), is a chemical with multiple industrial applications, however, it can be found in foods that are rich in carbohydrates. Due to its genotoxic and cytotoxic effects, AA has been classified as a potential carcinogen. With the use of spectrophotometry, ICP-OES, fluorescence spectroscopy, and microscopy cell growth, metabolic activity, apoptosis, ROS production, MDA formation, CAT and SOD activity, ionome balance, and chromosome segregation were determined in Schizosaccharomyces pombe. AA caused growth and metabolic activity retardation, enhanced ROS and MDA production, and modulated antioxidant enzyme activity. This led to damage to the cell homeostasis due to ionome balance disruption. Moreover, AA-induced oxidative stress caused alterations in the cell cycle regulation resulting in chromosome segregation errors, as 4.07% of cells displayed sister chromatid non-disjunction during mitosis. Ascorbic acid (AsA, Vitamin C), a strong natural antioxidant, was used to alleviate the negative impact of AA. Cell pre-treatment with AsA significantly improved AA impaired growth, and antioxidant capacity, and supported ionome balance maintenance mainly due to the promotion of calcium uptake. Chromosome missegregation was reduced to 1.79% (44% improvement) by AsA pre-incubation. Results of our multiapproach analyses suggest that AA-induced oxidative stress is the major cause of alteration to cell homeostasis and cell cycle regulation.

Review on Acrylamide: A Hidden Hazard in Fried Carbohydrate-Rich Food

Abstract:

Acrylamide is classified as a hazard whose formation in carbohydrate-rich food cooked at a high temperature has created much interest in the scientific community. The review attempts to comprehend the chemistry and mechanisms of formation of acrylamide and its levels in popular foods. A detailed study of the toxicokinetic and biochemistry, carcinogenicity, neurotoxicity, genotoxicity, interaction with biomolecules, and its effects on reproductive health has been presented. The review outlines the various novel and low-cost conventional as well as newer analytical techniques for the detection of acrylamide in foods with the maximum permissible limits. Various effective approaches that can be undertaken in industries and households for the mitigation of levels of acrylamide in foods have also been discussed. This review will assist to provide in depth understanding about acrylamide that will make it simpler to assess the risk to human health from the consumption of foods containing low amounts of acrylamide.

Multi-omics based strategy for toxicity analysis of acrylamide in Saccharomyces cerevisiae model

Although the toxicity of acrylamide (ACR) has been extensively investigated in different experimental models, its perturbations to multiple nodes of the cellular signaling network have not been systematically associated. In this study, changes at different omics layers in ACR exposed Saccharomyces cerevisiae cells were monitored using a multi-omics strategy. The results of the analysis highlighted the impairment of oxidative-reductive balance, energy metabolism, lipid metabolism, nucleotide metabolism, and ribosome function in yeast cells. Response to acute ACR damage, glutathione synthesis was upregulated, the process of protein degradation was accelerated, and the autophagy flux was initiated. Meanwhile, yeast upregulates gene expression levels of enzymes in carbohydrate metabolism and speeds up the oxidation process of fatty acids to compensate for energy depletion. Importantly, the multi-omics strategy captures features that have rarely been addressed in previous studies on the toxicology of ACR, including blocked de novo nucleotide synthesis, decreased levels of metabolic enzyme cofactors thiamine and D-biotin, increased intracellular concentrations of neurotoxic N-methyl d-aspartic acid and l-glutamic acid, and release of death mediators ceramide. The ACR perturbation network constructed in this work and the discovery of new damage features provide a theoretical basis for subsequent point-to-point toxicological studies.

Comprehensive analysis of metabolic changes in rats exposed to acrylamide

Acrylamide (ACR) is a widely used environmentally hazardous compound that is known to be neurotoxic, genotoxic, carcinogenic, and reproductive toxicity. It is widely present in soil, water, agents used in chemical industries, and food. It can be distributed to all organs and tissues, and can cause damage to various human systems and those of other animals. Previous metabolomics studies have mainly focused on metabolites in serum and urine, but have lacked comprehensive analysis of major organs and tissues. In the current study, a gas chromatography-massspectrometry method was used to investigate mechanisms underlying organ toxicity, in an effort to identify potentially sensitive biomarkers in the main target tissues of rats after ACR exposure. Male Sprague-Dawley rats were assigned to two groups; a control group and a group treated with 20 mg kg^-1 ACR intragastrically for 6 weeks. Metabolite changes in the two groups were statistically analyzed. The respective numbers of altered metabolites in the hippocampus, cortex, kidney, serum, heart, liver, and kidney fat were 21, 21, 17, 5, 15, 14, and 6. There were 14 metabolic pathways related to amino acid, fatty acid, purine, and energy metabolism, revealing that the toxic mechanism of ACR may involve oxidative stress, inflammation, and amino acid metabolism and energy disorders.

Preventive Effects of Three Polysaccharides on the Oxidative Stress Induced by Acrylamide in a Saccharomyces cerevisiae Model

Saccharomyces cerevisiae was used as a model to explore the preventive effect of two marine polysaccharides separately derived from Sepia esculenta ink (SIP) and Laminaria japonica (FL) as well as one terrestrial polysaccharides from Eleocharis tuberosa peel (WCPP) on toxic injury induced by acrylamide (AA). The growth of yeast was evaluated by kinetics indexes including doubling time, lag phase and maximum proliferation density. Meanwhile, intracellular redox state was determined by contents of MDA and GSH, and SOD activity. The results showed that AA inhibited yeast growth and destroyed the antioxidant defense system. Supplement with polysaccharides, the oxidative damage of cells was alleviated. According to the growth recovery of yeast, FL and WCPP had similar degree of capacity against AA associated cytotoxicity, while SIP was 1.5~2 folds as strong as FL and WCPP. SIP and FL significantly reduced production of MDA by AA administration. Moreover, SIP, FL and WCPP increased SOD activity and repressed GSH depletion caused by AA.

Is Acrylamide as Harmful as We Think? A New Look at the Impact of Acrylamide on the Viability of Beneficial Intestinal Bacteria of the Genus Lactobacillus

The impact of acrylamide (AA) on microorganisms is still not clearly understood as AA has not induced mutations in bacteria, but its epoxide analog has been reported to be mutagenic in Salmonella strains. The aim of the study was to evaluate whether AA could influence the growth and viability of beneficial intestinal bacteria. The impact of AA at concentrations of 0–100 µg/mL on lactic acid bacteria (LAB) was examined. Bacterial growth was evaluated by the culture method, while the percentage of alive, injured, and dead bacteria was assessed by flow cytometry after 24 h and 48 h of incubation. We demonstrated that acrylamide could influence the viability of the LAB, but its impact depended on both the AA concentration and the bacterial species. The viability of probiotic strain Lactobacillus acidophilus LA-5 increased while that of Lactobacillus plantarum decreased; Lactobacillus brevis was less sensitive. Moreover, AA influenced the morphology of L. plantarum, probably by blocking cell separation during division. We concluded that acrylamide present in food could modulate the viability of LAB and, therefore, could influence their activity in food products or, after colonization, in the human intestine.

Influence of Acrylamide Administration on the Neurochemical Characteristics of Enteric Nervous System (ENS) Neurons in the Porcine Duodenum

The digestive tract, especially the small intestine, is one of the main routes of acrylamide absorption and is therefore highly exposed to the toxic effect of acrylamide contained in food. The aim of this experiment was to elucidate the effect of low (tolerable daily intake—TDI) and high (ten times higher than TDI) doses of acrylamide on the neurochemical phenotype of duodenal enteric nervous system (ENS) neurons using the pig as an animal model. The experiment was performed on 15 immature gilts of the Danish Landrace assigned to three experimental groups: control (C) group—pigs administered empty gelatine capsules, low dose (LD) group—pigs administered capsules with acrylamide at the TDI dose (0.5 μg/kg body weight (b.w.)/day), and the high dose (HD) group—pigs administered capsules with acrylamide at a ten times higher dose than the TDI (5 μg/kg b.w./day) with a morning feeding for 4 weeks. Administration of acrylamide, even in a low (TDI) dose, led to an increase in the percentage of enteric neurons immunoreactive to substance P (SP), calcitonin gene-related peptide (CGRP), galanin (GAL), neuronal nitric oxide synthase (nNOS), and vesicular acetylcholine transporter (VACHT) in the porcine duodenum. The severity of the changes clearly depended on the dose of acrylamide and the examined plexus. The obtained results suggest the participation of these neuroactive substances in acrylamide-inducted plasticity and the protection of ENS neurons, which may be an important line of defence from the harmful action of acrylamide.

Thermal processing food-related toxicants: a review

Heterocyclic aromatic amines, acrylamide, 5-hydroxymethylfurfural, furan, polycyclic aromatic hydrocarbons, nitrosamines, acrolein, chloropropanols and chloroesters are generated toxicants formed in some foodstuffs, mainly starchy and protein-rich food during thermal treatment such as frying, roasting and baking. The formation of these chemical compounds is associated with development of aromas, colors and flavors. One of the challenges facing the food industry today is to minimize these toxicants without adversely affecting the positive attributes of thermal processing. To achieve this objective, it is essential to have a detailed understanding of the mechanism of formation of these toxicants in processed foods. All reviewed toxicants in that paper are classified as probable, possible or potential human carcinogens and have been proven to be carcinogenic in animal studies. The purpose of that review is to summarize some of the most frequent occurring heat-generated food toxicants during conventional heating, their metabolism and carcinogenicity. Moreover, conventional and microwave heating were also compared as two different heat treatment methods, especially how they change food chemical composition and which thermal food toxicants are formed during specific method.

Bioproduction of gold nanoparticles for photothermal therapy

Background: Photothermal response of plasmonic nanomaterials can be utilized for a number of therapeutic applications such as the ablation of solid tumors. Methods & results: Gold nanoparticles were prepared using different methods. After optimization, we applied an aqueous plant extract as the reducing and capping agent of gold and maximized the near-infrared absorption (650–900 nm). Resultant nanoparticles showed good biocompatibility when tested in vitro in human keratinocytes and yeast Saccharomyces cerevisiae. Gold nanoparticles were easily activated by controlled temperature with an ultrasonic water bath and application of a pulsed laser. Conclusion: These gold nanoparticles can be synthesized with reproducibility, modified with seemingly limitless chemical functional groups, with adequate controlled optical properties for laser phototherapy of tumors and targeted drug delivery.

Effect of dietary antioxidants on the cytostatic effect of acrylamide during copper-deficiency in Saccharomyces cerevisiae

Yeast grown on a copper deficient medium was used to study acrylamide toxicity, obviating the need for genetic manipulation and accompanying compensatory effects.

A new biological test utilising the yeast Saccharomyces cerevisiae for the rapid detection of toxic substances in water

This study evaluates the toxic effects of five substances (atropine, fenitrothion, potassium cyanide, mercuric chloride and lead nitrate) on the yeast Saccharomyces cerevisiae. It describes a new biological toxicity test based on inhibition of S. cerevisiae viability and compares it with two standard toxicity tests based on Daphnia magna mobility inhibition (EN ISO 6341) and Vibrio fischeri bioluminiscence inhibition (EN ISO 11348-2). The new biological test -S. cerevisiae lethal test - is cheaper and 24 times faster than the D. magna test. The test speed is comparable with the V. fischeri test but the new test is more sensitive for some substances. The test indicates reliably the presence of all used toxicants in water in concentrations which are significantly lower than the concentration in toxic or lethal doses for man. Therefore, this new toxicity test could be proposed for rapid detection of toxic substances in water.

Ascorbate and thiol antioxidants abolish sensitivity of yeast Saccharomyces cerevisiae to disulfiram

Sensitivity of baker’s yeast to disulfiram (DSF) and hypersensitivity of a mutant devoid of Cu, Zn-superoxide dismutase to this compound is reported, demonstrating that yeast may be a simple convenient eukaryotic model to study the mechanism of DSF toxicity. DSF was found to induce oxidative stress in yeast cells demonstrated by increased superoxide production and decrease of cellular glutathione content. Anoxic atmosphere and hydrophilic antioxidants (ascorbate, glutathione, dithiothreitol, cysteine, and N-acetylcysteine) ameliorated DSF toxicity to yeast indicating that oxidative stress plays a critical role in the cellular action of DSF.