Genotoxicity of acrylamide in human hepatoma G2 (HepG2) cells

Morphological analysis and cytotoxicity of acrylamide on SPC212 human mesothelioma cells: Do low doses induce proliferation, while high doses cause toxicity?

Acrylamide is broadly utilized in numerous areas with different purposes including being an additive, flocculating, sealing, dry strength improver and polymerizing agent, and so forth. Furthermore, it forms in certain food products at high temperatures. It poses serious hazard since its readily water-soluble and very reactive nature. Besides in vivo studies, several in vitro studies with various cell lines are carried out to evaluate its toxicity. However, of these cell line studies, there are no mesothelium or mesothelioma cell lines. To fill this lacuna, we aimed at examining various dose range of acrylamide on SPC212 human mesothelioma cell line. First, we executed MTT and neutral red cytotoxicity tests and ascertained IC50 dose. Next, we performed inverted, light (haematoxylin-eosin and May Grünwald), fluorescent (DAPI) and confocal microscope (AO/EB) analyses as well as immunohistochemistry for Bax, Bcl-2 and PCNA proteins. As a result, we found IC50 of acrylamide at 2.65 mM. Starting from 3.13 mM of acrylamide dose, a deep decrease in cell proliferation was observed. Particularly in MTT assay, a proliferative action of acrylamide was detected at 0.39 and 0.78 mM, supported with inverted microscope images. In light microscope analysis, several cellular degenerations, including condensed and kidney-shaped nucleus were evident. In AO/EB staining, cells with apoptotic characteristics augmented dose-dependently, being upheld by a parallel uptick in Bax and a dimunition in Bcl-2 staining. Besides, PCNA decreased at IC50 dose of acrylamide. This is the acrylamide-associated first study conducted on SPC212 mesothelioma cells encompassing advanced morphological analysis. We believe this study to be an incentive for future studies.

Genotoxic and Mutagenic Effects of the Alternaria Mycotoxin Alternariol in Combination with the Process Contaminant Acrylamide

Humans are constantly exposed to mixtures of different xenobiotics through their diet. One emerging concern is the Alternaria mycotoxin alternariol (AOH), which can occur in foods typically contaminated by the process contaminant acrylamide (AA). AA is a byproduct of the Maillard reaction produced in carbohydrate-rich foods during thermal processing. Given the genotoxic properties of AOH and AA as single compounds, as well as their potential co-occurrence in food, this study aimed to assess the cytotoxic, genotoxic, and mutagenic effects of these compounds in combination. Genotoxicity was assessed in HepG2 cells by quantifying the phosphorylation of the histone γ-H2AX, induced as a response to DNA double-strand breaks (DSBs). Mutagenicity was tested in Salmonella typhimurium strains TA98 and TA100 by applying the Ames microplate format test. Our results showed the ability of AOH and AA to induce DSBs and increase revertant numbers in S. typhimurium TA100, with AOH being more potent than AA. However, no synergistic effects were observed during the combined treatments. Notably, the results of the study suggest that the compounds exert mutagenic effects primarily through base pair substitutions. In summary, the data indicate no immediate cause for concern regarding synergistic health risks associated with the consumption of foods co-contaminated with AOH and AA.

Antioxidants Amelioration Is Insufficient to Prevent Acrylamide and Alpha-Solanine Synergistic Toxicity in BEAS-2B Cells

Cells produce free radicals and antioxidants when exposed to toxic compounds during cellular metabolism. However, free radicals are deleterious to lipids, proteins, and nucleic acids. Antioxidants neutralize and eliminate free radicals from cells, preventing cell damage. Therefore, the study aims to determine whether the antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) will ameliorate the maximum dose of acrylamide and alpha (α)-solanine synergistic toxic effects in exposed BEAS-2B cells. These toxic compounds are consumed worldwide by eating potato products. BEAS-2B cells were simultaneously treated with BHA 10 μM and BHT 20 μM and incubated in a 5% CO2 humidified incubator for 24 h, followed by individual or combined treatment with acrylamide (3.5 mM) and α-solanine (44 mM) for 48 h, including the controls. Cell morphology, DNA, RNA, and protein were analyzed. The antioxidants did not prevent acrylamide and α-solanine synergistic effects in exposed BEAS-2B cells. However, cell morphology was altered; polymerase chain reaction (PCR) showed reduced RNA constituents but not DNA. In addition, the toxic compounds synergistically inhibited AKT/PKB expression and its downstream genes. The study showed BHA and BHT are not protective against the synergetic toxic effects of acrylamide and α-solanine in exposed BEAS-2B cells.

Therapeutic role of melatonin on acrylamide-induced hepatotoxicity in pinealectomized rats: Effects on oxidative stress, NF-κB signaling pathway, and hepatocellular proliferation

Acrylamide (AA) is formed in some foods by the cooking process at high temperatures, and it could be a carcinogen in humans and rodents. The purpose of the current study was to reveal the possible protective effects of melatonin against AA-induced hepatic oxidative stress, hepatic inflammation, and hepatocellular proliferation in pinealectomized rats. Hence, the sham and pinealectomized rats were consecutively given AA alone (25 mg/kg) or with melatonin (10 mg/kg) for 21 days. Melatonin acts as an antioxidant, anti-inflammatory, and antiapoptotic agent and introduces as a therapeutic strategy for AA-induced hepatotoxicity. Melatonin supplementation reduced AA-caused liver damage by decreasing the serum AST, ALT, and ALP levels. Melatonin raised the activities of SOD and CAT and levels of GSH and suppressed hepatic inflammation (TNF-α) and hepatic oxidative stress in liver tissues. Moreover, histopathological alterations and the disturbances in immunohistochemical expression of NF-κB and Ki67 were improved after melatonin treatment in AA-induced hepatotoxicity. Overall, our results demonstrate that melatonin supplementation exhibits adequate hepatoprotective effects against hepatotoxicity of AA on pinealectomized rat liver architecture and the tissue function through the equilibration of oxidant/antioxidant status, the regulation of cell proliferation and the suppression of the release of proinflammatory cytokines.

Influence of baking and frying conditions on acrylamide formation in various prepared bakery, snack, and fried products

The core objective of the present study was to evaluate the influence of baking/frying times and temperatures on the formation of acrylamide in bakery, snack, and fried products such as biscuits, muffins, pizza, cakes, samosa, paratha rolls, nuggets, and potato cutlets during baking/frying at different times and temperature conditions. First of all, the raw material, especially flour, was tested for its proximate composition and rheological characteristics. The quantification of acrylamide produced during the processing of different products was carried out through the HPLC method. A sensory evaluation of these food samples was also carried out to find out the acceptability differences. The raw material was found to have good rheological properties and proximate composition. The results revealed that different times and temperature regimes influenced the formation of acrylamide in those products. Among the bakery products, the highest concentrations of acrylamide were observed in biscuits (126.52 μg/kg) followed by muffins (84.24 μg/kg), cake (71.21 μg/kg), and pizza (62.42 μg/kg). The higher contents of acrylamide were found in paratha roll (165.92 μg/kg) compared to samosa (100.43 μg/kg), whereas among snacks, potato cutlets (135.71 μg/kg) showed higher concentrations than nuggets (43.04 μg/kg). It was observed that baking or frying all the investigated products at higher temperatures produced slightly more acrylamide concentrations. The prepared products in the present study were also accepted sensorially by the panel of judges. So, it was concluded that baking or frying at higher temperatures resulted in higher concentrations of acrylamide compounds in different products in the present study.

Acrylamide induced hepatotoxicity through oxidative stress: Mechanisms and interventions

SIGNIFICANCE

Acrylamide (AA) widely exists in the environment. Studies have demonstrated that AA has neurotoxicity and potential carcinogenicity in humans, and genotoxicity and severe hepatotoxicity in animals. As the critical metabolism organ for AA, the liver is the primary attacking target of AA. This review summarizes the recent advances in hepatotoxicity mechanism through AA-induced oxidative stress in rodent livers and hepatic cell lines, this is beneficial to assess risks of AA exposure and explore effective intervention methods for AA hepatotoxicity.

RECENT ADVANCES

Accumulating evidences have indicated that AA-induced oxidative stress is responsible for its hepatotoxicity. The changes in homological and biochemical indexes such as activities of hepatic antioxidant enzymes have been elucidated with the occurrence and development of oxidative stress. Also, the molecular mechanisms underlying AA-induced hepatotoxicity through oxidative stress have been mainly explained by apoptosis, inflammatory and autophagic pathways.

CRITICAL ISSUES

This review is focusing on the molecular mechanism of hepatotoxicity through AA-induced oxidative stress, this can provide a theoretical basis for the assessment of AA-induced health risk and finding potential intervention targets.

FUTURE DIRECTIONS

Epigenetic modifications like miRNAs and modulation of the gut microbiome involved in AA toxification pathway must be investigated, and will provide novel insights to unravel the toxification mechanism and intervention strategy for AA hepatotoxicity.

Cytotoxic effects of Roundup Classic and its components on NE-4C and MC3T3-E1 cell lines determined by biochemical and flow cytometric assays

Cytotoxic effects of the market leading broad-spectrum, synthetic herbicide product Roundup Classic, its active ingredient glyphosate (in a form of its isopropylamine (IPA) salt) and its formulating surfactant polyethoxylated tallowamine (POE-15) were determined on two murine cell lines, a neuroectodermal stem cell-like (NE-4C) and a high alkaline phosphatase activity osteoblastic cell line (MC3T3-E1). Cytotoxicity, genotoxicity, effects on cell viability and cell cycles were examined in five flow cytometry tests, the two former of which were compared by the enzymatic-assay and the alkaline single cell gel electrophoresis (Comet) assay. All of the tests indicated the NE-4C cells being more sensitive, than the MC3T3-E1 cell line to the treatments with the target compounds. Higher sensitivity differences were detected in the viability test by flow cytometry (7-9-fold), than by the MTT assay (1.5-3-fold); in the genotoxicity test by the Comet assay (3.5-403-fold), than by the DNA-damage test (9.3-158-fold); and in the apoptosis test by the Annexin V dead cell kit (1.1-12.7-fold), than by the Caspase 3/7 kit (1-6.5-fold). Cell cycle assays indicated high count of cells (~70%) in the G0/G1 phase for MC3T3-E1 cells, than in NE-4C cell (~40%) after 24 h. The order of the inhibitory potency of the target substances has unequivocally been POE-15 > Roundup Classic > > glyphosate IPA salt.

Testing the Effects of Cinnamon Extract Supplementation on Inflammation and Oxidative Stress Induced by Acrylamide

We investigated the effects of cinnamon water extract supplementation on inflammation and oxidative stress induced by acrylamide in rats. This revealed acrylamide-intoxicated control group had significant higher levels of malondialdehyde, tumor necrosis factor-alpha (TNF-α), high-sensitive C-reactive protein (hs-CRP), leptin and alanine transaminase, and lower levels of total antioxidant capacity compared to the negative control group. In contrast, cinnamon extract administration remedied the levels of total antioxidant capacity, malondialdehyde, TNF-α, hs-CRP, and leptin in the treatment groups. However, there was no significant effect on adiponectin or liver enzymes. This chapter presents a protocol involving production of the acrylamide-induced oxidative stress model, the aqueous extraction of cinnamon powder, and measurement of inflammatory and oxidative stress markers.

Assessing the combinatorial cytotoxicity of the exogenous contamination with BDE-209, bisphenol A, and acrylamide via high-content analysis

Food is often exposed to multiple types of contaminants, and the coexistence of contaminants may have antagonistic, additive or synergistic effects. This study investigated the combinatorial toxicity of the three most widespread exogenous contaminants, decabrominated diphenyl ether (BDE-209), bisphenol A (BPA), and acrylamide (ACR) to HepG2 cells. A mathematical model (Chou-Talalay) and high-content analysis (HCA) were used to probe the nature of the contaminants' interactions and their cytotoxicity mechanisms, respectively. The results highlighted that for the individual pollutants, the cytotoxicity order was BDE-209> BPA > ACR, and varying combinations of contaminants exhibited additive/synergistic effects. In general, combining multiple contaminants significantly increased intracellular reactive oxygen species (ROS), Ca²⁺ flux, DNA damage and Caspase-3, and decreased mitochondrial membrane potential (MMP) and nucleus roundness, indicating that the additive or synergistic mechanism of the combined contaminations was disturbance to multiple organelles. This study emphasizes the complexity of human exposure to food contaminants and provides a scientific basis for formulating strict regulatory standards.

Acrylamide Induced Oxidative Cellular Senescence in Embryonic Fibroblast Cell Line (NIH 3T3): A Protection by Carvacrol

Background: Stress-induced cellular senescence is a perpetual state of cell cycle arrest occurring in proliferating cells in response to stressful conditions. It is believed that oxidative stress plays a unique role in this process. As a reactive chemical compound that can induce oxidative stress, acrylamide is widely applied in several fields. Carvacrol is a liquid phenolic monoterpenoid found in essential oils of some plants and is known for its antioxidant and anticarcinogenic properties. Objectives: The current study aimed to evaluate the effects of carvacrol on oxidative stress and cellular senescence induced by acrylamide in the NIH 3T3 cell line. Methods: NIH 3T3 embryonic fibroblast cells were exposed to different concentrations of acrylamide, carvacrol, and H2O2 in a cell culture medium. The level of β-galactosidase (SA-β-gal) activity, as a marker of cellular senescence, was measured using staining and quantitative assays. Furthermore, to measure oxidative stress parameters, the content of glutathione and lipid peroxidation were determined. Results: Acrylamide could induce premature senescence evident by the elevated lipid peroxidation and SA-β-gal activity and declined cell viability and glutathione. Moreover, carvacrol showed beneficial effects on both acrylamide- and H2O2-induced cellular senescence by significantly reversing or subsiding the effect of oxidative stress and mediating its consequences. Conclusions: It can be concluded that carvacrol has protective effects against oxidative cellular senescence induced by acrylamide in the NIH 3T3 cell line.

Acrylamide inhibits vaccinia virus through vimentin-independent anti-viral granule formation

The replication and assembly of vaccinia virus (VACV), the prototypic poxvirus, occurs exclusively in the cytoplasm of host cells. While the role of cellular cytoskeletal components in these processes remains poorly understood, vimentin-a type III intermediate filament-has been shown to associate with viral replication sites and to be incorporated into mature VACV virions. Here, we employed chemical and genetic approaches to further investigate the role of vimentin during the VACV lifecycle. The collapse of vimentin filaments, using acrylamide, was found to inhibit VACV infection at the level of genome replication, intermediate- and late-gene expression. However, we found that CRISPR-mediated knockout of vimentin did not impact VACV replication. Combining these tools, we demonstrate that acrylamide treatment results in the formation of anti-viral granules (AVGs) known to mediate translational inhibition of many viruses. We conclude that vimentin is dispensable for poxvirus replication and assembly and that acrylamide, as a potent inducer of AVGs during VACV infection, serves to bolster cell's anti-viral response to poxvirus infection.

Modulatory Effect of Probiotics on Proinflammatory Cytokine Levels in Acrylamide-Treated Rats

The aims of this study are to investigate the effect of acrylamide on the level of proinflammatory cytokines in the blood of acrylamide-treated rats and to find the modulatory impact of probiotics on those cytokines. Thirty-two rats were divided into four groups: rats which received 20 mg acrylamide, acrylamide with 20 mg probiotics, acrylamide with 200 mg probiotics, and standard water and food (groups 1-4, respectively). The serum levels of cytokines were measured on days 0, 15, and 30. Group 1 showed an increased serum level of IL-1β, IL-6, and TNF-α after 15 days, and they decreased in day 30. Serum IL-6 level was significantly decreased on days 15 and 30 in rats in group 2 compared to the controls. TNF-α and IL-1β levels were not statistically different after treated with probiotics. The exposure of rats to acrylamide led to increased systemic inflammation as evidenced by higher levels of proinflammatory cytokines, and probiotics can modulate this inflammation.

Antioxidant, Antigenotoxic, and Hepatic Ameliorative Effects of Quercetin/Zinc Complex on Cadmium-Induced Hepatotoxicity and Alterations in Hepatic Tissue Structure

Applications of medicinal uses of metals and their complexes have been gaining major clinical significance, especially during the COVID-19 pandemic. The ligation behavior of quercetin (Q), a flavonoid, and Zn metal, i.e., the Zn/Q complex, was fully characterized based on molar conductance, infrared (IR) spectra, elemental analysis, electronic spectra, thermogravimetric analysis, proton nuclear magnetic resonance (1H-NMR), and transmission electron microscopy (TEM) in our lab. Hepatotoxicity was induced by cadmium (CdCl2). A total of 40 male albino rats were randomly distributed into the following four groups: Control, hepatotoxic group (CdCl2), Zn/Q-treated group, and group treated with a combination of CdCl2 and Zn/Q. Serum hepatic enzymes (AST, ALT, and LDH), total protein, and enzymatic and nonenzymatic antioxidant levels were determined. Histology and TEM for hepatic tissues, in addition to the gene expression of SOD as an antioxidant enzyme in the hepatic tissues, were evaluated. The Q/Zn treatment demonstrated potent protective effects against CdCl2-induced sever oxidative stress and suppressed hepatic toxicity, genotoxicity, liver enzyme disturbances, and structural alterations. In conclusion, the Zn/Q complex produced a high potent antioxidant effect against the oxidative injury and genotoxicity induced by CdCl2 and could be considered to be a potent ameliorative hepatoprotective agent against CdCl2 hepatotoxicity, which could be beneficial during the COVID-19 pandemic.

Mitochondrial, lysosomal and DNA damages induced by acrylamide attenuate by ellagic acid in human lymphocyte

Acrylamide (AA), is an important contaminant formed during food processing under high temperature. Due to its potential neurotoxicity, reproductive toxicity, hepatotoxicity, immunotoxicity, genotoxicity and carcinogenicity effects, this food contaminant has been recognized as a human health concern. Previous studies showed that acrylamide-induced toxicity is associated with active metabolite of acrylamide by cytochrome P450 enzyme, oxidative stress, mitochondrial dysfunction and DNA damage. In the current study, we investigated the role of oxidative stress in acrylamide's genotoxicity and therapeutic potential role of ellagic acid (EA) in human lymphocytes. Human lymphocytes were simultaneously treated with different concentrations of EA (10, 25 and 50 μM) and acrylamide (50 μM) for 4 h at 37°C. After 4 hours of incubation, the toxicity parameters such cytotoxicity, ROS formation, oxidized/reduced glutathione (GSH/GSSG) content, malondialdehyde (MDA) level, lysosomal membrane integrity, mitochondria membrane potential (ΔΨm) collapse and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were analyzed using biochemical and flow cytometry evaluations. It has been found that acrylamide (50 μM) significantly increased cytotoxicity, ROS formation, GSH oxidation, lipid peroxidation, MMP collapse, lysosomal and DNA damage in human lymphocytes. On the other hand, cotreatment with EA (25 and 50 μM) inhibited AA-induced oxidative stress which subsequently led to decreasing of the cytotoxicity, GSH oxidation, lipid peroxidation, MMP collapse, lysosomal and DNA damage. Together, these results suggest that probably the co-exposure of EA with foods containing acrylamide could decrease mitochondrial, lysosomal and DNA damages, and oxidative stress induced by acrylamide in human body.

In vitro mutagenicity of selected environmental carcinogens and their metabolites in MutaMouse FE1 lung epithelial cells

Chemicals in commerce or under development must be assessed for genotoxicity; assessment is generally conducted using validated assays (e.g. Tk mouse lymphoma assay) as part of a regulatory process. Currently, the MutaMouse FE1 cell mutagenicity assay is undergoing validation for eventual use as a standard in vitro mammalian mutagenicity assay. FE1 cells have been shown to be metabolically competent with respect to some cytochrome P450 (CYP) isozymes; for instance, they can convert the human carcinogen benzo[a]pyrene into its proximate mutagenic metabolite. However, some contradictory results have been noted for other genotoxic carcinogens that require two-step metabolic activation (e.g. 2-acetylaminofluorene and 2-amino-3-methylimidazo[4,5-f]quinoxaline). Here, we examined three known or suspected human carcinogens, namely acrylamide, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 4-aminobiphenyl (4-ABP), together with their proximate metabolites (i.e. glycidamide, N-OH-PhIP and N-OH-4-ABP), to aid in the validation of the FE1 cell mutagenicity assay. Assessments of the parent compounds were conducted both in the presence and absence of an exogenous metabolic activation mixture S9; assessments of the metabolites were in the absence of S9. The most potent compound was N-OH-PhIP -S9, which elicited a mutant frequency (MF) level 5.3-fold over background at 5 µM. There was a 4.3-fold increase for PhIP +S9 at 5 µM, a 1.7-fold increase for glycidamide -S9 at 3.5 mM and a 1.5-fold increase for acrylamide +S9 at 4 mM. Acrylamide -S9 elicited a marginal 1.4-fold MF increase at 8 mM. Treatment with PhIP -S9, 4-ABP ±S9 and N-OH-4-ABP -S9 failed to elicit significant increases in lacZ MF with any of the treatment conditions tested. Gene expression of key CYP isozymes was quantified by RT-qPCR. Cyp1a1, 1a2 and 1b1 are required to metabolise PhIP and 4-ABP. Results showed that treatment with both compounds induced expression of Cyp1a1 and Cyp1b1 but not Cyp1a2. Cyp2e1, which catalyses the bioactivation of acrylamide to glycidamide, was not induced after acrylamide treatment. Overall, our results confirm that the FE1 cell mutagenicity assay has the potential for use alongside other, more traditional in vitro mutagenicity assays.

Genotoxicity of selected pyrrolizidine alkaloids in human hepatoma cell lines HepG2 and Huh6

INTRODUCTION

Pyrrolizidine alkaloids (PAs) are found in many plant species as secondary metabolites which affect humans via contaminated food sources, herbal medicines and dietary supplements. Hundreds of compounds belonging to PAs have been identified. PAs undergo hepatic metabolism, after which they can induce hepatotoxicity and carcinogenicity. Many aspects of their mechanism of carcinogenicity are still unclear and it is important for human risk assessment to investigate this class of compounds further.

MATERIAL AND METHODS

Human hepatoma cells HepG2 were used to investigate the genotoxicity of different chemical structural classes of PAs, namely europine, lycopsamine, retrorsine, riddelliine, seneciphylline, echimidine and lasiocarpine, in the cytokinesis-block micronucleus (CBMN) assay. The different ester type PAs europine, seneciphylline, and lasiocarpine were also tested in human hepatoma Huh6 cells. Six different PAs were investigated in a crosslink comet assay in HepG2 cells.

RESULTS

The maximal increase of micronucleus formation was for all PAs in the range of 1.64-2.0 fold. The lowest concentrations at which significant induction of micronuclei were found were 3.2 μM for lasiocarpine and riddelliine, 32 μM for retrorsine and echimidine, and 100 μM for seneciphylline, europine and lycopsamine. Significant induction of micronuclei by lasiocarpine, seneciphylline, and europine were achieved in Huh6 cells at similar concentrations. Reduced tail formation after hydrogen peroxide treatment was found in the crosslink comet assay for all diester type PAs, while an equimolar concentration of the monoesters europine and lycopsamine did not significantly reduce DNA migration.

CONCLUSION

The widely available human hepatoma cell lines HepG2 and Huh6 were suitable for the assessment of PA-induced genotoxicity. Selected PAs confirmed previously published potency rankings in the micronucleus assay. In HepG2 cells, the crosslinking activity was related to the ester type, which is a first report of PA mediated effects in the comet assay.

Selenium and L-Carnitine Ameliorate Reproductive Toxicity Induced by Cadmium in Male Mice

Cadmium (Cd) has been reported to reduce male fertility, impair reproductive capacity, and play a major role in the pathogenesis of infertility. This study was conducted to investigate the possible protective role of Selenium (Se) and L-carnitine (LC) against the adverse effects induced by Cd on the male reproductive system in mice. Animals were randomly divided into seven groups (n = 10); control group and six treated groups, as follows: Cd (0.35 mg/kg), Se (0.87 mg/kg), LC (10 mg/kg), and a combination of either Se or LC and then a combination of both with Cd, and all animals were injected for a period of 30 days. Exposure of Cd showed a significant decrease in enzymatic antioxidant activities, deficiency in reproductive performance, decrease serum testosterone level, severe changes in the histopathological architecture, and higher degree of damages and appearance of unblemished DNA strands. Treatment with Se and LC has the highly synergistic and ameliorates the damaging effect of Cd on the testis through the elevation of the enzymatic antioxidant and diminish histopathological abnormalities and DNA damage.

Mutagenicity of acrylamide and glycidamide in human TP53 knock-in (Hupki) mouse embryo fibroblasts

Acrylamide is a suspected human carcinogen formed during high-temperature cooking of starch-rich foods. It is metabolised by cytochrome P450 2E1 to its reactive metabolite glycidamide, which forms pre-mutagenic DNA adducts. Using the human TP53 knock-in (Hupki) mouse embryo fibroblasts (HUFs) immortalisation assay (HIMA), acrylamide- and glycidamide-induced mutagenesis was studied in the tumour suppressor gene TP53. Selected immortalised HUF clones were also subjected to next-generation sequencing to determine mutations across the whole genome. The TP53-mutant frequency after glycidamide exposure (1.1 mM for 24 h, n = 198) was 9% compared with 0% in cultures treated with acrylamide [1.5 (n = 24) or 3 mM (n = 6) for 48 h] and untreated vehicle (water) controls (n = 36). Most glycidamide-induced mutations occurred at adenines with A > T/T > A and A > G/T > C mutations being the most common types. Mutations induced by glycidamide occurred at specific TP53 codons that have also been found to be mutated in human tumours (i.e., breast, ovary, colorectal, and lung) previously associated with acrylamide exposure. The spectrum of TP53 mutations was further reflected by the mutations detected by whole-genome sequencing (WGS) and a distinct WGS mutational signature was found in HUF clones treated with glycidamide that was again characterised by A > G/T > C and A > T/T > A mutations. The WGS mutational signature showed similarities with COSMIC mutational signatures SBS3 and 25 previously found in human tumours (e.g., breast and ovary), while the adenine component was similar to COSMIC SBS4 found mostly in smokers’ lung cancer. In contrast, in acrylamide-treated HUF clones, only culture-related background WGS mutational signatures were observed. In summary, the results of the present study suggest that glycidamide may be involved in the development of breast, ovarian, and lung cancer.

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.

Revisiting the evidence for genotoxicity of acrylamide (AA), key to risk assessment of dietary AA exposure

The weight of evidence pro/contra classifying the process-related food contaminant (PRC) acrylamide (AA) as a genotoxic carcinogen is reviewed. Current dietary AA exposure estimates reflect margins of exposure (MOEs) < 500. Several arguments support the view that AA may not act as a genotoxic carcinogen, especially not at consumer-relevant exposure levels: Biotransformation of AA into genotoxic glycidamide (GA) in primary rat hepatocytes is markedly slower than detoxifying coupling to glutathione (GS). Repeated feeding of rats with AA containing foods, bringing about uptake of 100 µg/kg/day of AA, resulted in dose x time-related buildup of AA-hemoglobin (Hb) adducts, whereas GA-Hb adducts remained within the background. Since hepatic oxidative biotransformation of AA into GA was proven by simultaneous urinary mercapturic acid monitoring it can be concluded that at this nutritional intake level any GA formed in the liver from AA is quantitatively coupled to GS to be excreted as mercapturic acid in urine. In an oral single dose–response study in rats, AA induced DNA N⁷-GA-Gua adducts dose-dependently in the high dose range (> 100 µg/kg b w). At variance, in the dose range below 100 µg/kg b.w. down to levels of average consumers exposure, DNA N⁷ -Gua lesions were found only sporadically, without dose dependence, and at levels close to the lower bound of similar human background DNA N⁷-Gua lesions. No DNA damage was detected by the comet assay within this low dose range. GA is a very weak mutagen, known to predominantly induce DNA N⁷-GA-Gua adducts, especially in the lower dose range. There is consensus that DNA N⁷-GA-Gua adducts exhibit rather low mutagenic potency. The low mutagenic potential of GA has further been evidenced by comparison to preactivated forms of other process-related contaminants, such as N-Nitroso compounds or polycyclic aromatic hydrocarbons, potent food borne mutagens/carcinogens. Toxicogenomic studies provide no evidence supporting a genotoxic mode of action (MOA), rather indicate effects on calcium signalling and cytoskeletal functions in rodent target organs. Rodent carcinogenicity studies show induction of strain- and species-specific neoplasms, with MOAs not considered likely predictive for human cancer risk. In summary, the overall evidence clearly argues for a nongenotoxic/nonmutagenic MOA underlying the neoplastic effects of AA in rodents. In consequence, a tolerable intake level (TDI) may be defined, guided by mechanistic elucidation of key adverse effects and supported by biomarker-based dosimetry in experimental systems and humans.

Hepatoprotective effect of Raspberry ketone and white tea against acrylamide-induced toxicity in rats

The current investigation was accomplished to evaluate the hepatoprotective effect of White tea and Raspberry Ketone against toxicity induced by acrylamide in rats. Sixty adult male rats were divided randomly into group (I) control; group (II) rats received RK with dose (6 mg/kg/day); Group III: rats received 5 ml of WT extract/kg/day; Group IV rats received AA (5 mg/kg/day); Group V: rats administrated with both AA (5 mg/kg/day) and RK (6 mg/kg/day) and Group VI: rats administrated AA (5 mg/kg/day) and 5 ml of WT extract/kg/day. The biochemical assays exhibited a significant increase in serum levels of Adiponectin, AST, ALT, ALP of the group treated with acrylamide if compared to the control group and an improvement in their levels of groups V and VI. The histopathological and immunohistochemical findings confirm the biochemical observations. In conclusion, the present investigation proved that the supplementation of WT and RK enhanced the liver histology, immunohistochemistry and biochemistry against the oxidative stress induced by acrylamide.

Acrylamide Decreases Cell Viability, and Provides Oxidative Stress, DNA Damage, and Apoptosis in Human Colon Adenocarcinoma Cell Line Caco-2

Acrylamide (AA) toxicity remains an interesting subject in toxicological research. The aim of the research performed in this paper was to determine mechanisms of cyto- and genotoxic effects of AA on the human colon adenocarcinoma cell line Caco-2, to estimate the inhibitory concentration (IC)₅₀ values in cell viability assays, to measure the basal and oxidative DNA damage as well as the oxidative stress leading to apoptosis, and to assess the morphological changes in cells using microscopic methods. It has been proven that AA induces cytotoxic and genotoxic effects on Caco-2 cells. Higher cytotoxic activity was gained in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay compared with the PrestoBlue assay, with IC₅₀ values of 5.9 and 8.9 mM after 24 h exposure, respectively. In the single-cell gel electrophoresis assay, the greatest DNA damage was caused by the highest concentration of acrylamide equal to 12.5 mM (89.1% ± 0.9%). AA also induced oxidative DNA damage and generated reactive oxygen species (ROS), which was concentration dependent and correlated with the depletion of mitochondrial membrane potential and apoptosis induction. In the microscopic staining of cells, AA in the dosage close to the IC₅₀ induced morphological changes typical for apoptosis. Taken together, these results demonstrate that AA has a pro-oxidative effect on Caco-2 cells, leading to apoptotic cell death.

The modulatory effect of triclosan on the reversion of the activated phenotype of LX-2 hepatic stellate cells

Hepatic diseases leading to fibrosis affect millions of individuals worldwide and are a major public health challenge. Although, there have been many advances in understanding hepatic fibrogenesis, an effective therapy remains elusive. Studies focus primarily on activation of the hepatic stellate cells (HSCs), the principal fibrogenic cells in the liver; however, fewer numbers of studies have examined molecular mechanisms that deactivate HSC, controlling the profibrogenic phenotype. In the present study, we evaluated cellular and molecular actions of the chemical triclosan (TCS) in reverting activated HSCs to a quiesced phenotype. We demonstrated that the inhibition of the enzyme fatty acid synthase by TCS in activated HSCs promotes survival of the cells and triggers cellular and molecular changes that promote cellular phenotypic reversion, offering potentially new therapeutic directions.

Carcinogenic and neurotoxic risks of acrylamide consumed through caffeinated beverages among the lebanese population

The present study aims to quantify acrylamide in caffeinated beverages including American coffee, Lebanese coffee, espresso, instant coffee and hot chocolate, and to determine their carcinogenic and neurotoxic risks. A survey was carried for this purpose whereby 78% of the Lebanese population was found to consume at least one type of caffeinated beverages. Gas Chromatography Mass Spectrometry analysis revealed that the average acrylamide level in caffeinated beverages is 29,176 μg/kg sample. The daily consumption of acrylamide from Lebanese coffee (10.9 μg/kg-bw/day), hot chocolate (1.2 μg/kg-bw/day) and Espresso (7.4 μg/kg-bw/day) was found to be higher than the risk intake for carcinogenicity and neurotoxicity as set by World Health Organization (WHO; 0.3-2 μg/kg-bw/day) at both the mean (average consumers) and high (high consumers) dietary exposures. On the other hand, American coffee (0.37 μg/kg-bw/day) was shown to pose no carcinogenic or neurotoxic risks among the Lebanese community for consumers with a mean dietary exposure. The study shows alarming results that call for regulating the caffeinated product industry by setting legislations and standard protocols for product preparation in order to limit the acrylamide content and protect consumers. In order to avoid carcinogenic and neurotoxic risks, we propose that WHO/FAO set acrylamide levels in caffeinated beverages to 7000 μg acrylamide/kg sample, a value which is 4-folds lower than the average acrylamide levels of 29,176 μg/kg sample found in caffeinated beverages sold in the Lebanese market. Alternatively, consumers of caffeinated products, especially Lebanese coffee and espresso, would have to lower their daily consumption to 0.3-0.4 cups/day.

Negative association between acrylamide exposure and body composition in adults: NHANES, 2003-2004

BACKGROUND/OBJECTIVES

Acrylamide is present in mainstream cigarette smoke and in some food prepared at high temperature. Animal studies have shown that acrylamide exposure reduces body weight. Prenatal exposure to acrylamide also has been linked to reduced birth weight in human. Whether acrylamide exposure is associated with altered body compositions in adults is not clear.

SUBJECTS/METHODS

We selected 3623 subjects (aged ⩾20 years) from a National Health and Nutrition Examination Survey (NHANES) in 2003-2004 to determine the relationship among hemoglobin adducts of acrylamide (HbAA), hemoglobin adducts of glycidamide (HbGA) and body composition (body measures, bioelectrical impedance analysis (BIA), dual energy x-ray absorptiometry (DXA)). Data were adjusted for potential confounding variables.

RESULTS

The geometric means and 95% CI concentrations of HbAA and HbGA were 60.48 (59.32-61.65) pmol/g Hb and 55.64 (54.40-56.92) pmol/g Hb, respectively. After weighting for sampling strategy, we identified that one-unit increase in natural log-HbAA, but not HbGA, was associated with reduction in body measures (body weight, body mass index (BMI), subscapular/triceps skinfold), parameters of BIA (fat-free mass, fat mass, percent body fat, total body water) and parameters of DXA (android fat mass, android percent fat, gynoid fat/lean mass, gynoid percent mass, android to gynoid ratio). Subgroup analysis showed that these associations were more evident in subjects at younger age, male gender, whites, lower education level, active smokers and those with lower BMI.

CONCLUSIONS

Higher concentrations of HbAA are associated with a decrease in body composition in the US general population. Further studies are warranted to clarify this association.

Transcriptomics analysis and hormonal changes of male and female neonatal rats treated chronically with a low dose of acrylamide in their drinking water

Acrylamide is known to produce follicular cell tumors of the thyroid in rats. RccHan Wistar rats were exposed in utero to a carcinogenic dose of acrylamide (3 mg/Kg bw/day) from gestation day 6 to delivery and then through their drinking water to postnatal day 35. In order to identify potential mechanisms of carcinogenesis in the thyroid glands, we used a transcriptomics approach. Thyroid glands were collected from male pups at 10 PM and female pups at 10 AM or 10 PM in order to establish whether active exposure to acrylamide influenced gene expression patterns or pathways that could be related to carcinogenesis. While all animals exposed to acrylamide showed changes in expected target pathways related to carcinogenesis such as DNA repair, DNA replication, chromosome segregation, among others; animals that were sacrificed while actively drinking acrylamide-laced water during their active period at night showed increased changes in pathways related to oxidative stress, detoxification pathways, metabolism, and activation of checkpoint pathways, among others. In addition, thyroid hormones, triiodothyronine (T3) and thyroxine (T4), were increased in acrylamide-treated rats sampled at night, but not in quiescent animals when compared to controls. The data clearly indicate that time of day for sample collection is critical to identifying molecular pathways that are altered by the exposures. These results suggest that carcinogenesis in the thyroids of acrylamide treated rats may ensue from several different mechanisms such as hormonal changes and oxidative stress and not only from direct genotoxicity, as has been assumed to date.

Acrylamide: inhibition of formation in processed food and mitigation of toxicity in cells, animals, and humans

Potentially toxic acrylamide is largely derived from the heat-inducing reactions between the amino group of the amino acid asparagine and carbonyl groups of glucose and fructose in plant-derived foods including cereals, coffees, almonds, olives, potatoes, and sweet potatoes. This review surveys and consolidates the following dietary aspects of acrylamide: distribution in food, exposure and consumption by diverse populations, reduction of the content in different food categories, and mitigation of adverse in vivo effects. Methods to reduce acrylamide levels include selecting commercial food with a low acrylamide content, selecting cereal and potato varieties with low levels of asparagine and reducing sugars, selecting processing conditions that minimize acrylamide formation, adding food-compatible compounds and plant extracts to food formulations before processing that inhibit acrylamide formation during processing of cereal products, coffees, teas, olives, almonds, and potato products, and reducing multiorgan toxicity (antifertility, carcinogenicity, neurotoxicity, teratogenicity). The herein described observations and recommendations are of scientific interest for food chemistry, pharmacology, and toxicology, but also have the potential to benefit nutrition, food safety, and human health.

Effects of dietary extra virgin olive oil and its fractions on antioxidant status and DNA damage in the heart of rats co-exposed to aluminum and acrylamide

Oxidative stress generated by an excessive production of free radicals has been linked to the development of several health problems such as cardiovascular diseases. We investigated the protective efficacy of Extra Virgin Olive Oil (EVOO) and its lipophilic fraction (OOLF) and hydrophilic fraction (OOHF) against the cardiotoxicity and DNA damage induced by co-exposure to aluminum (AlCl3) and acrylamide (ACR). Rats were divided into eight groups of six each: controls, AlCl3 (50 mg per kg body weight) administered via drinking water and ACR (20 mg per kg body weight) given by gavage, combined group plus EVOO (300 μl); combined group plus the hydrophilic fraction (1 ml); combined group plus the lipophilic fraction (300 μl); extra virgin olive oil (EVOO) and its fractions were administered daily by gavage for 21 days. Three other groups, considered as positive controls, received either EVOO, OOLF or OOLH. Exposure of rats to both AlCl3 and ACR provoked oxidative stress objectified by an increase in MDA, AOPP and a decrease in GSH, NPSH and vitamin C levels. The activities of CAT, GPx and SOD were also decreased. EVOO and its OOLF fraction exhibited a pronounced enhancement of antioxidant status while a partial recovery in the antioxidant status was obtained with the OOHF fraction. Plasma LDH and CK activities, TC, LDL-C levels, TC/HDL-C and LDL-C/HDL-C ratios were increased, while HDL-C and TG decreased in rats treated with both AlCl3 and ACR. Co-administration of EVOO, OOLF or OOHF to treated rats restored cardiac biomarkers and lipid profile to near-normal values. Histological studies and DNA damage confirmed the biochemical parameters and the beneficial role of EVOO and its two fractions. Our results suggest that extra virgin olive oil and its two fractions can decrease the frequency of cardiac complications and genotoxicity.

Inhibition of Neurosphere Formation in Neural Stem/Progenitor Cells by Acrylamide

Previous studies showed that transplantation of cultured neural stem/progenitor cells (NSPCs) could improve functional recovery for various neurological diseases. This study aims to develop a stem cell-based model for predictive toxicology of development in the neurological system after acrylamide exposure. Treatment of mouse (KT98/F1B-GFP) and human (U-1240 MG/F1B-GFP) NSPCs with 0.5 mM acrylamide resulted in the inhibition of neurosphere formation (definition of self-renewal ability in NSPCs), but not inhibition of cell proliferation. Apoptosis and differentiation of KT98 (a precursor of KT98/F1B-GFP) and KT98/F1B-GFP are not observed in acrylamide-treated neurospheres. Analysis of secondary neurosphere formation and differentiation of neurons and glia illustrated that acrylamide-treated KT98 and KT98/F1B-GFP neurospheres retain the NSPC properties, such as self-renewal and differentiation capacity. Correlation of acrylamide-inhibited neurosphere formation with cell-cell adhesion was observed in mouse NSPCs by live cell image analysis and the presence of acrylamide. Protein expression levels of cell adhesion molecules [neural cell adhesion molecule (NCAM) and N-cadherin] and extracellular signal-regulated kinases (ERK) in acrylamide-treated KT98/F1B-GFP and U-1240 MG/F1B-GFP neurospheres demonstrated that NCAM decreased and phospho-ERK (pERK) increased, whereas expression of N-cadherin remained unchanged. Analysis of AKT (protein kinase B, PKB)/β-catenin pathway showed decrease in phospho-AKT (p-AKT) and cyclin D1 expression in acrylamide-treated neurospheres of KT98/F1B-GFP. Furthermore, PD98059, an ERK phosphorylation inhibitor, attenuated acrylamide-induced ERK phosphorylation, indicating that pERK contributed to the cell proliferation, but not in neurosphere formation in mouse NSPCs. Coimmunoprecipitation results of KT98/F1B-GFP cell lysates showed that the complex of NCAM and fibroblast growth factor receptor 1 (FGFR1) is present in the neurosphere, and the amount of this complex decreases after acrylamide treatment. Our results reveal that acrylamide inhibits neurosphere formation through the disruption of the neurosphere architecture in NSPCs. The downregulation of cell-cell adhesion resulted from decreasing the levels of NCAM as well as the formation of NCAM/ FGFR complex.

Acrylamide Induces Senescence in Macrophages through a Process Involving ATF3, ROS, p38/JNK, and a Telomerase-Independent Pathway

Senescence, which is irreversible cell cycle arrest, is induced by various types of DNA damage, including genotoxic stress. Senescent cells show dysregulation of tumor suppressor genes and other regulators of cellular proliferation. Activating transcription factor 3 (ATF3) plays a pleiotropic role in biological processes through genotoxic stress. In this study, we examined the effects of acrylamide (ACR), a genotoxic carcinogen, on cellular senescence and the molecular mechanisms of ATF3 function in macrophages. Treatment of macrophages with ACR at low concentrations (<1.0 mM) resulted in senescence-like morphology and an increase in senescence-associated β-galactosidase (SA-β-gal) activity. Exposure of macrophages to ACR led to stress-induced, telomerase-independent senescence. In addition, ACR treatment for 1, 3, or 5 days showed a concentration-dependent increase in ATF3 expression and G0/G1 phase arrest. To better understand the role of ATF3 in controlling the senescence response to ACR, SA-β-gal activity was examined using ATF3 knockdown and overexpression. ACR-mediated senescence was significantly decreased by knockdown of ATF3, whereas it was increased with ATF3 overexpression. We found that ATF3 regulated p53 and p21 levels. ATF3 also played an important role in regulating intracellular reactive oxygen species (ROS) production in response to ACR treatment. Moreover, phosphorylation of p38 and JNK kinases, which were activated during ATF3-mediated senescence, was observed in ACR-treated macrophages. Taken together, these results suggest that ATF3 contributes to ACR-induced senescence by enhancing ROS production, activating p38 and JNK kinases, and promoting the ATF3-dependent expression of p53, resulting in regulation of cellular senescence in macrophages.

Two-year carcinogenicity study of acrylamide in Wistar Han rats with in utero exposure

Acrylamide is an important chemical with widespread industrial and other uses in addition to generalized population exposure from certain cooked foods. Previous rat studies to assess the carcinogenic potential of acrylamide have been carried out exclusively in the Fischer 344 rat with identification of a number of tumors amongst which mesotheliomas of the tunica vaginalis is an important tumor endpoint in the classification of acrylamide as a 'probably human carcinogen. In a rat carcinogenicity study to determine the human relevance of mesotheliomas Wistar Han rats were exposed to 0, 0.5, 1.5, or 3.0mg acrylamide/kg body weight/day in drinking water starting at gestation day 6. At the end of two years, mammary gland fibroadenomas in females and thyroid follicular cell tumors in both sexes were the only tumors increased in acrylamide treated rats. These tumor endpoints have rat-specific modes of action suggesting less likelihood of human cancer risk than previously estimated. This study demonstrates that tunica vaginalis mesotheliomas are strain specific and not likely of genotoxic origin.

Toxicity assessment of chlorinated wastewater effluents by using transcriptome-based bioassays and Fourier transform mass spectrometry (FT-MS) analysis

Effects of chlorination on the toxicity of wastewater effluents treated by activated sludge (AS) and submerged membrane bioreactor (S-MBRB) systems to HepG2 human hepatoblastoma cells were investigated. In addition to the cytotoxicity and genotoxicity assays, the DNA microarray-based transcriptome analysis was performed to evaluate the change in types of biological impacts on HepG2 cells of the effluents by chlorination. Effluent organic matter (EfOM) and disinfection by-products (DBPs) were also characterized by using Fourier transform mass spectrometry (FT-MS). Although no significant induction of genotoxicity was observed by chlorination for both effluents, the chlorination elevated the cytotoxicity of AS effluent but reduced that of S-MBRB effluent. The FT-MS analyses revealed that more DBPs including nitrogenated DBPs (N-DBPs) were formed in the AS effluent than in the S-MBRB effluent by chlorination, supporting the increased cytotoxicity of AS effluent. The lower O/C ratio of S-MBRB EfOM suggests that a large number of organic molecules were detoxified by chlorination, which consequently decreased the cytotoxicity of S-MBRB effluent. Integration of all the results highlights that both cytotoxicity and biological impacts of chlorinated wastewater effluents were clearly dependent on the EfOM characteristics such as DBPs and O/C ratio, namely, on types of treatment systems.

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.

Cytotoxic effects of acrylamide in nerve growth factor or fibroblast growth factor 1-induced neurite outgrowth in PC12 cells

Acrylamide is a neurological and reproductive toxicant in humans and laboratory animals; however, the neuron developmental toxicity of acrylamide remains unclear. The aims of this study are to investigate the cytotoxicity and neurite outgrowth inhibition of acrylamide in nerve growth factor (NGF)- or fibroblast growth factor 1 (FGF1)-mediated neural development of PC12 cells. MTS assay showed that acrylamide treatment suppresses NGF- or FGF1-induced PC12 cell proliferation in a time- and dose-dependent manner. Quantification of neurite outgrowth demonstrated that 0.5 mM acrylamide treatment resulted in significant decrease in differentiation of NGF- or FGF1-stimulated PC12 cells. This decrease is accompanied with the reduced expression of growth-associated protein-43, a neuronal marker. Moreover, relative levels of pERK, pAKT, pSTAT3 and pCREB were increased within 5-10 min when PC12 cells were treated with NGF or FGF1. Acrylamide (0.5 mM) decreases the NGF-induced activation of AKT-CREB but not ERK-STAT3 within 20 min. Similarly, acrylamide (0.5 mM) decreases the FGF1-induced activation of AKT-CREB within 20 min. In contrast to the NGF treatment, the ERK-STAT3 activation that was induced by FGF1 was slightly reduced by 0.5 mM acrylamide. We further showed that PI3K inhibitor (LY294002), but not MEK inhibitor (U0126), could synergize with acrylamide (0.5 mM) to reduce the cell viability and neurite outgrowth in NGF- or FGF1-stimulated PC12 cells. Moreover, acrylamide (0.5 mM) increased reactive oxygen species (ROS) activities in NGF- or FGF1-stimulated PC12 cells. This increase was reversed by Trolox (an ROS scavenging agent) co-treatment. Together, our findings reveal that NGF- or FGF1-stimulation of the neuronal differentiation of PC12 cells is attenuated by acrylamide through the inhibition of PI3K-AKT-CREB signaling, along with the production of ROS.

Positive association between urinary levels of 8-hydroxydeoxyguanosine and the acrylamide metabolite N-acetyl-S-(propionamide)-cysteine in adolescents and young adults

Acrylamide is present in mainstream cigarette smoke and in some foods prepared at high temperatures. Animal studies have shown that acrylamide exposure increases oxidative stress; however, it is not known if this also occurs in humans. We recruited 800 subjects (mean age, 21.3 years, range, 12-30 years) from a population-based sample of Taiwanese adolescents and young adults to determine if urinary levels of the acrylamide metabolite N-acetyl-S-(propionamide)-cysteine (AAMA) and the oxidative stress product 8-hydroxydeoxyguanosine (8-OHdG) are associated. The mean (SD) AAMA and 8-OHdG were 76.54 (76.42)μg/L and 3.48 (2.37)μg/L, respectively. In linear regression analyses, a 1-unit increase in natural log AAMA was significantly associated with an increase in natural log 8-OHdG (μg/g creatinine) (β=0.044, SE=0.019, P=0.020) after controlling for covariates. Subpopulation analyses showed AAMA and 8-OHdG were significantly associated with males, adolescents, non-current smokers, without alcohol consumption, subjects, body mass index ≥ 24, and homeostasis model assessment of insulin resistance score ≥ 0.9. In conclusion, higher urinary AAMA concentrations were associated with increased levels of urinary 8-OHdG in this cohort. Further studies are warranted to determine if there is a causal relationship between acrylamide exposure and oxidative stress.