Adult Rat Liver After Subchronic Acrylamide Treatment: Histological, Stereological and Biochemical Study

SUMMARY: Acrylamide (AA) is a widely used chemical and an important monomer in various industrial and laboratory processes. In addition, AA is formed during processing of starchy food at high temperature. The aim of our study was to examine effects of subchronic AA treatment on adult rat liver using histological, stereological and biochemical methods. Adult male Wistar rats were treated with AA at doses of 25 mg/kg b.w. and 50 mg/kg b.w. for three weeks. Stereological analysis showed decrease of volume density of hepatocyte cytoplasm, and increase of volume density of hepatocyte nuclei and nucleocytoplasmic ratio in AA50mg group. Immunohistochemical analysis of the liver sections showed that treatment with AA50mg increase the percentage of PCNA positive cells, while the percentage of caspase 3 positive cells was not affected by AA. PAS-staining showed that glycogen content in hepatocytes was not affected by AA. Serological examination revealed increase of lipid peroxidation in AA50mg group, while total protein concentration, protein thiol group level, as well as, paraoxonase 1 activity were not changed in AA-exposed animals. Stereological and immunohistochemical analyses of adult liver sections suggest increase of proliferation in AA50mg group, while increase of lipid peroxidation in serum of AA50mg group indicates oxidative stress induction.

La acrilamida (AA) es un químico ampliamente utilizado y un monómero importante en varios procesos industriales y de laboratorio. Además, la AA se forma durante el procesamiento de alimentos ricos en almidón a altas temperaturas. El objetivo de nuestro estudio fue examinar los efectos del tratamiento con AA subcrónica en el hígado de rata adulta utilizando métodos histológicos, estereológicos y bioquímicos. Se trataron ratas Wistar macho adultas con AA a dosis de 25 mg/kg p.v. y 50 mg/kg de peso corporal por tres semanas. El análisis estereológico mostró una disminución de la densidad del volumen del citoplasma de los hepatocitos y un aumento de la densidad del volumen de los núcleos de los hepatocitos y la relación nucleocitoplasmática en el grupo de 50 mg de AA. El análisis inmunohistoquímico de las secciones de hígado mostró que el tratamiento con 50 mg de AA aumentó el porcentaje de células positivas para PCNA, mientras que el porcentaje de células positivas para caspasa 3 no se vio afectado por AA. La tinción con PAS mostró que el contenido de glucógeno en los hepatocitos no se vio afectado por AA. El examen serológico reveló un aumento de la peroxidación de lípidos en el grupo de 50 mg de AA, mientras que la concentración de proteína total, el nivel del grupo tiol de proteína y la actividad de paraoxonasa 1 no cambiaron en los animales expuestos a AA. Los análisis estereológicos e inmunohistoquímicos de secciones de hígado adulto sugieren un aumento de la proliferación en el grupo AA50 mg, mientras que el aumento de la peroxidación lipídica en suero del grupo AA50 mg indica inducción de estrés oxidativo.

Cytotoxic, genotoxic, and carcinogenic effects of acrylamide on human lung cells.

While an association between acrylamide (AC) exposure and the risk of developing cancer has been shown in some studies, there are very limited data on the relationship between AC exposure and lung cancer risk. Thus, we investigated the cytotoxic, genotoxic, and carcinogenic effects of AC on human lung bronchial epithelial cell line (BEAS-2B cells). AC (5 and 10 mM) significantly decreased the cell viability for all treatment times. The comet assay results showed that AC (0.5, 1 and 5 mM) increased the DNA tail (%), tail moment and olive tail moment. By using immunofluorescence, we found that AC (0.5, 1 and 5 mM) induced the formation of both phosphorylated form of the histone H2 variant H2AX (gH2AX) and p53-binding protein 1 (53BP1) foci. AC-treated BEAS-2B cells exhibited various morphological and cytoplasmic changes. The transformed cells can induce form foci and significantly increase the number of colonies in soft agar. We showed for the first time that AC could induce DNA strand breaks, cell transformation, and anchorage-independent growth in BEAS-2B cells. Therefore, AC exposure can induce carcinogenesis in lung cells and may be a risk for lung cancer formation. Further studies are necessary to make a possible risk assessment in humans.

Effects of acute oral exposure to acrylamide on histological structures of the stomach in Wistar rats / Efectos de la exposición oral aguda a la acrilamida sobre las estructuras histológicas del estómago en ratas Wistar

SUMMARY: Acrylamide is a toxic chemical substance with wide implementation in chemical industry. In 2002 the presence of acrylamide was discovered in foods rich in starch which are prepared at high temperatures. The aim of this study was to investigate the histopathological changes in the gastric tissue in Wistar rats induced with injection of oral acrylamide. The research was carried out 6 groups of 5 animals (Wistar rats), two control groups and four experimental groups. Histological changes in the stomach tissue of Wistar rats are seen as a direct slight damage of the surface epithelium, accompanynig inflammatory reaction and renewal of the epithelium. Examined inflammatory and degenerative parameters show a positive correlation with respect to dose and time of exposition to acrylamide. Knowing the mechanism of action of these toxic substances, allows to apply adequate prevention in nutrition and make an appropriate choice of therapeutic methods.

RESUMEN: La acrilamida es una sustancia química tóxica con amplia aplicación en la industria química. En el año 2002 se determinó la presencia de acrilamida en alimentos ricos en almidón preparados a altas temperaturas. El objetivo de este estudio fue investigar los cambios histopatológicos en el tejido gástrico en ratas Wistar inducidos con inyección de acrilamida oral. La investigación se llevó a cabo en 6 grupos de 5 animales, dos grupos control y cuatro grupos experimentales. Los cambios histológicos en el tejido del estómago de las ratas Wistar se ven como un ligero daño directo del epitelio superficial, que acompaña a la reacción inflamatoria y la renovación del epitelio. Los parámetros inflamatorios y degenerativos examinados muestran una correlación positiva con respecto a la dosis y el tiempo de exposición a la acrilamida. El conocimiento del mecanismo de acción de estas sustancias tóxicas permite aplicar una prevención adecuada en nutrición y hacer una elección oportuna de los métodos terapéuticos.

Long-term acrylamide exposure exacerbates brain and lung pathology in a mouse malaria model.

The consumption of dietary acrylamide (ACR), a carcinogen, results in the dysfunction of various organs and the immune system. However, the impact of ACR exposure on the progression of infectious diseases is unknown. This study investigated the effect of ACR on the progression of malaria infection using a mouse model of malaria. C57BL/6 mice were continuously treated with ACR at a dose of 20 mg/kg bodyweight/day for six weeks (long-term exposure) or phosphate-buffered saline (PBS). Next, the mice were infected with the rodent malaria parasite, Plasmodium berghei NK65 (PbNK). Parasitemia and survival rate were analyzed in the different treatment groups. Magnetic resonance imaging (MRI) and histopathological analyses were performed to evaluate the effect of ACR exposure on the morphology of various organs. Long-term ACR exposure exacerbated PbNK-induced multiorgan dysfunction. MRI and histopathological analysis revealed signs of encephalomeningitis and acute respiratory distress syndrome in the PbNK-infected long-term ACR exposure mice, which decreased the survival rate of mice, but not in the PbNK-infected long-term PBS exposure group. These findings enhance our understanding of the impact of ACR on the progression of infectious diseases, such as malaria.

Dietary Acrylamide Intake and the Risks of Renal Cell, Prostate, and Bladder Cancers: A Japan Public Health Center-Based Prospective Study.

Acrylamide can be carcinogenic to humans. However, the association between the acrylamide and the risks of renal cell, prostate, and bladder cancers in Asians has not been assessed. We aimed to investigate this association in the Japan Public Health Center-based Prospective Study data in 88,818 Japanese people (41,534 men and 47,284 women) who completed a food frequency questionnaire in the five-year follow-up survey in 1995 and 1998. A validated food frequency questionnaire was used to assess the dietary acrylamide intake. Cox proportional hazard regression models were used to estimate hazard ratios and 95% confidence intervals (CIs). During a mean follow-up of 15.5 years (15.2 years of prostate cancer), 208 renal cell cancers, 1195 prostate cancers, and 392 bladder cancers were diagnosed. Compared to the lowest quintile of acrylamide intake, the multivariate hazard ratios for the highest quintile were 0.71 (95% CI: 0.38-1.34, p for trend = 0.294), 0.96 (95% CI: 0.75-1.22, p for trend = 0.726), and 0.87 (95% CI: 0.59-1.29, p for trend = 0.491) for renal cell, prostate, and bladder cancers, respectively, in the multivariate-adjusted model. No significant associations were observed in the stratified analyses based on smoking. Dietary acrylamide intake was not associated with the risk of renal cell, prostate, and bladder cancers.

Exploring the possible neuroprotective and antioxidant potency of lycopene against acrylamide-induced neurotoxicity in rats' brain.

Acrylamide (Ac) is a carbonyl compound extracted from hydrated acrylonitrile with a significantly high chemical activity. It is widely existed and used in food processing, industrial manufacturing and laboratory personnel work. However, lycopene (Ly) is a most potent natural antioxidant among various common carotenoids extracted from red plants. Nevertheless, little is known about the relationship of Ac-induced neurotoxicity and the ameliorative role of Ly in the regulation of oxidative and antioxidant capacity during Ac exposure. Therefore, this work sought to investigate the neurotoxicity induced by Ac exposure and the potential modulatory role of Ly by reversing the brain dysfunctions during Ac exposure. For this purpose, forty male albino rats were assigned into four equal groups. Control group received distilled water, Ly group was given with a daily dose of 10 mg/kg bw, Ac group was given with a daily dose of 25 mg/kg bw, and Ac-Ly group was gavaged Ac plus Ly at the same doses as the former groups. All treatments were given orally for 21 consecutive days. The concentrations of antioxidants (reduced glutathione and glutathione peroxidase) and oxidative stress (malondialdehyde, nitric oxide and protein carbonyl) biomarkers, as well as neurotransmitters (serotonin and dopamine) and acetylcholinesterase (AChE) were measured in the brain homogenates. An immunohistochemical staining was applied with anti-GFPA antibody to determine the severity of astrocytosis. The in vivo study with rat model demonstrated that Ac exposure significantly decline the hematological parameters, brain neurotransmitters concentrations and AChE activity, as well as levels of antioxidant biomarkers but markedly elevate the levels of oxidative stress biomarkers. Moreover, marked histological alterations and astrocytosis were observed through the increased number of GFAP immunopositively cells in cerebral, cerebellar and hippocampal tissues compared with the other groups. Interestingly, almost all of the previously mentioned parameters were retrieved in Ac-Ly group compared to Ac group. These findings conclusively indicate that Ly oral administration provides adequate protection against the neurotoxic effects of Ac on rat brain tissue function and structure through modulations of oxidative and antioxidant activities.

Dietary Acrylamide Intake and the Risk of Hematological Malignancies: The Japan Public Health Center-Based Prospective Study.

Acrylamide, which is present in many daily foods, is a probable human carcinogen. In 2002, it was identified in several common foods. Subsequently, western epidemiologists began to explore the relationship between dietary acrylamide exposure and cancer risk; however, limited suggestive associations were found. This prospective study aimed to examine the association between dietary acrylamide intake and the risk of hematological malignancies, including malignant lymphoma (ML), multiple myeloma (MM), and leukemia. We enrolled 85,303 participants in the Japan Public Health Center-based Prospective study on diet and cancer as from 1995. A food frequency questionnaire that included data on acrylamide in all Japanese foods was used to assess dietary acrylamide intake. We applied multivariable adjusted Cox proportional hazards models to reckon hazard ratios (HRs) for acrylamide intake for both categorical variables (tertiles) and continuous variables. After 16.0 median years of follow-up, 326 confirmed cases of ML, 126 cases of MM, and 224 cases of leukemia were available for final multivariable-adjusted analysis. HRs were 0.87 (95% confidence interval [CI]: 0.64-1.18) for ML, 0.64 (95% CI: 0.38-1.05) for MM, and 1.01 (95% CI: 0.71-1.45) for leukemia. Our results implied that acrylamide may not be related to the risk of hematological malignancies.

Dietary acrylamide intake and risk of women's cancers: a systematic review and meta-analysis of prospective cohort studies.

This systematic review and meta-analysis was done to review earlier publications on the association between dietary acrylamide intake and risk of breast, endometrial and ovarian cancers. We performed a systematic search in the online databases of PubMed, ISI Web of Science and Scopus for relevant publications up to August 2020. Prospective cohort studies that considered dietary acrylamide as the exposure variable and breast, endometrial or ovarian cancer as the main outcome variable or as one of the outcome variables were included in this systematic review and meta-analysis. A total of fourteen cohort studies were included in the meta-analysis. We found no significant association between dietary acrylamide intake and the risk of breast (relative risk (RR) 0·95; 95 % CI 0·90, 1·01), endometrial (RR 1·03; 95 % CI 0·89, 1·19) and ovarian cancers (RR 1·02; 95 % CI 0·84, 1·24). In addition, we observed no significant association between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers in different subgroup analyses by smoking status, menopausal status, BMI status and different types of breast cancer. In conclusion, no significant association was found between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers.

Dietary Acrylamide Intake and the Risk of Pancreatic Cancer: The Japan Public Health Center-Based Prospective Study.

Acrylamide is a probable carcinogen in humans. Few studies have assessed dietary acrylamide intake and the risk of pancreatic cancer; however, these studies are based on Western populations. Our purpose was to investigate the association of dietary acrylamide intake with the risk of pancreatic cancer utilizing data from the Japan Public Health Center-based Prospective Study. We evaluated the data of 89,729 participants aged 45-74 years, who replied to a questionnaire on past medical history and lifestyle habits from 1995-1998. Dietary acrylamide intake was estimated utilizing a validated food frequency questionnaire. We calculated the hazard ratios and 95% confidence intervals by using Cox proportional-hazards regression models. The average follow-up was 15.2 years, and 576 cases of pancreatic cancer were diagnosed. In the multivariate-adjusted model, an association between dietary acrylamide intake and pancreatic cancer risk was not demonstrated (hazard ratio for the highest vs. lowest quartile = 0.83, 95% confidence interval: 0.65-1.05, p for trend = 0.07). Furthermore, in the analyses stratified by sex, smoking status, coffee consumption, green tea consumption, alcohol consumption, and body mass index, no significant association was detected. Dietary acrylamide intake was not associated with the pancreatic cancer risk in Japanese individuals.

Synthesis and in vitro characterization of a preactivated thiolated acrylic acid/acrylamide-methylpropane sulfonic acid copolymer as a mucoadhesive sprayable polymer.

AIM: Development of a preactivated thiomer as sprayable excipient for mucoadhesive formulations. METHODS: CG4500 (acrylic acid/acrylamide-methyl propane sulfonic acid copolymer) was thiolated by conjugation with L-cysteine and preactivated by further modification with 2-mercaptonicotinic acid (MNA) in a two-step synthesis and characterized regarding degree of modification and cytotoxicity on Caco-2 cells. The mucoadhesive properties of this novel thiomer were evaluated via rheological synergism, tensile and mucosal residence time studies. Furthermore, the sprayability of the thiomer was evaluated. RESULTS: The newly synthesized derivatives CG4500-SH and CG4500-S-S-MNA showed mean coupling rates of 651 µmol thiol groups and 264 µmol MNA per gram polymer, respectively. Even for the unmodified polymer a rheological synergism was observed with isolated porcine intestinal mucus, which was 2.81-fold higher in case of the preactivated thiomer. Mucoadhesion studies on freshly excised porcine intestinal mucosa confirmed these results via a 2.43-fold higher total work of adhesion and a 2.31-fold higher mucosal residence time of the preactivated thiomer. In sprayability tests it was shown that solutions of the preactivated thiomer could be sprayed in concentrations up to 12% (m/V). CONCLUSION: The novel polymer CG4500-S-S-MNA is a promising sprayable excipient for mucoadhesive formulations.

Variations in the estimated intake of acrylamide from food in the Japanese population.

BACKGROUND: Due to concerns of carcinogenicity, it is necessary to assess long-term acrylamide exposure in individuals. Whether the available methods of estimating acrylamide intake can indicate long-term exposure remains unknown. We examined variations in the estimated dietary acrylamide intake of the Japanese population. METHODS: The study included 240 participants aged 40-74 years who were a part of the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT). Twelve-day dietary records (DRs) were collected over a one-year period, and food frequency questionnaires (FFQs) were collected twice during the year. Dietary acrylamide intake was estimated from an acrylamide content database. Within-individual variations and between-individual variations were calculated using the random effects model. A linear regression analysis was performed to identify foods with large between-individual variations. RESULTS: The ratios of within-individual variance to between-individual variation were 3.2 for men and 4.3 for women. Days of DRs required to estimate the usual individual intake within 20% of the true mean intake with 95% confidence were 60 days for men and 66 days for women. Coffee/cocoa, potato, and green tea contributed to between-individual variations, in that order, and seven foods contributed to 93% of the between-individual variation. CONCLUSIONS: Estimating the acrylamide intake using DRs requires an extended data collection period to estimate the intragroup ranking and habitual intake of individuals. Long-term exposure assessments should be based on methods with less potential for measurement errors, such as the use of biomarkers.

Metabonomics analysis of liver in rats administered with chronic low-dose acrylamide.

The current study aimed to investigate the hepatotoxicity of rats administered with chronic low-dose acrylamide (AA) by using metabonomics technology on the basis of ultraperformance liquid chromatography-mass spectrometry (UPLC-MS). A total of 40 male Wistar rats were randomly divided into the following four groups: control, low-dose AA (0.2 mg/kg bw, non-carcinogenic end-point based on the induction of morphological nerve changes in rats), middle-dose AA (1 mg/kg bw), and high-dose AA (5 mg/kg bw). The rats continuously received AA by administering it in drinking water daily for 16 weeks. After the treatment, rat livers were collected for metabonomics analysis and histopathology examination. Principal components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) were used to investigate the metabonomics profile changes in rat liver tissues and screen the potential biomarkers.Fourteen metabolites were identified with significant changes in intensities (increased or decreased compared with the control group) as a result of treatment (p < 0.05 or p < 0.01). These metabolites included tauro-b-muricholic acid, docosapentaenoic acid, sphingosine 1-phosphate, taurodeoxycholic acid, lysoPE(20:5), cervonyl carnitine, linoleyl carnitine, docosahexaenoic acid, lysoPC(20:4), lysoPE(18:3), PA(20:4), stearidonyl carnitine, alpha-linolenic acid, and lysoPA(18:0).Results showed that chronic exposure to AA at NOAEL (0.2 mg/kg bw) exhibited no toxic effect in rat livers at the metabolic level. AA induced oxidative stress to the liver and disrupted lipid metabolism. The results of liver histopathology examination further supported the metabonomic results.

Genotoxic and Epigenotoxic Alterations in the Lung and Liver of Mice Induced by Acrylamide: A 28 Day Drinking Water Study.

Acrylamide has been classified as a "Group 2A carcinogen" (probably carcinogenic to humans) by the International Agency for Research on Cancer. The carcinogenicity of acrylamide is attributed to its well-recognized genotoxicity. In the present study, we investigated the effect of acrylamide on epigenetic alterations in mice. Female B6C3F1 mice received acrylamide in drinking water for 28 days, at doses previously used in a 2 year cancer bioassay (0, 0.0875, 0.175, 0.35, and 0.70 mM), and the genotoxic and epigenetic effects were investigated in lungs, a target organ for acrylamide carcinogenicity, and livers, a nontarget organ. Acrylamide exposure resulted in a dose-dependent formation of N7-(2-carbamoyl-2-hydroxyethyl)guanine and N3-(2-carbamoyl-2-hydroxyethyl)adenine in liver and lung DNA. In contrast, the profiles of global epigenetic alterations differed between the two tissues. In the lungs, acrylamide exposure resulted in a decrease of histone H4 lysine 20 trimethylation (H4K20me3), a common epigenetic feature of human cancer, while in the livers, there was increased acetylation of histone H3 lysine 27 (H3K27ac), a gene transcription activating mark. Treatment with 0.70 mM acrylamide also resulted in substantial alterations in the DNA methylation and whole transcriptome in the lungs and livers; however, there were substantial differences in the trends of DNA methylation and gene expression changes between the two tissues. Analysis of differentially expressed genes showed a marked up-regulation of genes and activation of the gene transcription regulation pathway in livers, but not lungs. This corresponded to increased histone H3K27ac and DNA hypomethylation in livers, in contrast to hypermethylation and transcription silencing in lungs. Our results demonstrate that acrylamide induced global epigenetic alterations independent of its genotoxic effects, suggesting that epigenetic events may determine the organ-specific carcinogenicity of acrylamide. Additionally this study provides strong support for the importance of epigenetic alterations, in addition to genotoxic events, in the mechanism of carcinogenesis induced by genotoxic chemical carcinogens.

Interaction between dietary acrylamide intake and genetic variants for estrogen receptor-positive breast cancer risk.

PURPOSE: The association between dietary acrylamide intake and estrogen receptor-positive (ER+) breast cancer risk in epidemiological studies is inconsistent. By analyzing gene-acrylamide interactions for ER+ breast cancer risk, we aimed to clarify the role of acrylamide intake in ER+ breast cancer etiology. METHODS: The prospective Netherlands Cohort Study on diet and cancer includes 62,573 women, aged 55-69 years. At baseline, a random subcohort of 2589 women was sampled from the total cohort for a case-cohort analysis approach. Dietary acrylamide intake of subcohort members (n = 1449) and ER+ breast cancer cases (n = 844) was assessed with a food frequency questionnaire. We genotyped single nucleotide polymorphisms (SNPs) in genes in acrylamide metabolism, sex steroid systems, oxidative stress and DNA repair. Multiplicative interaction between acrylamide intake and SNPs was assessed with Cox proportional hazards analysis, based on 20.3 years of follow-up. RESULTS: Unexpectedly, there was a statistically non-significant inverse association between acrylamide and ER+ breast cancer risk among all women but with no clear dose-response relationship, and no association among never smokers. Among the results for 57 SNPs and 2 gene deletions, rs1056827 in CYP1B1, rs2959008 and rs7173655 in CYP11A1, the GSTT1 gene deletion, and rs1052133 in hOGG1 showed a statistically significant interaction with acrylamide intake for ER+ breast cancer risk. CONCLUSIONS: This study did not provide evidence for a positive association between acrylamide intake and ER+ breast cancer risk. If anything, acrylamide was associated with a decreased ER+ breast cancer risk. The interaction with SNPs in CYP1B1 and CYP11A1 suggests that acrylamide may influence ER+ breast cancer risk through sex hormone pathways.

Effect of oral exposure to acrylamide on biochemical and hematologic parameters in Wistar rats.

The toxic effects of ACR monomer include carcinogenesis, cellular genotoxic, and neurotoxicity. In this study, we examined the effect of acrylamide on biochemical and hematologic parameters in Wistar rats and explored the renal and hepatic function of these animals through a complementary anatomopathologic study. For it, thirty female Wistar rats aged 4 weeks and weighing 100 ± 10 g were housed six animals per cage and divided as follows: two groups were exposed for 2 months to drinking water containing 5 mg (Group 2) or 10 mg acrylamide (Group 3); one group of 12 rats received the median lethal dose of acrylamide by gavage (Group 4); and the control group (Group 1) received pure water. The results clearly showed that acrylamide affects various biochemical parameters, such as creatinine, urea, and serum globulin levels and the lipid balance, which are directly related to renal and hepatic dysfunction and disruption of the hematologic system. In addition, the data revealed changes in the complete blood count (CBC); significant increases in the number of leukocytes (9.95 ± 1.44 and 10.44 ± 1.21) and lymphocytes (6.11 ± 0.48 and 6.33 ± 0.76) in Groups 3 and 4, respectively; and decreases in total protein (88.95 ± 6.36), albumin (37.65 ± 1.65) and α-1 globulin levels (24.84 ± 2.10) in Group 3. The anatomopathologic study confirmed liver damage in the animals administered an acrylamide containing diet compared with those in the control group. The present study confirmed the effects of acrylamide on different hematologic, biochemical and immunologic parameters, with a specific focus on the liver and kidney, and on the induction of neurotoxic disorders. The results showed that oral exposure to acrylamide via drinking water or gavage induces kidney damage, hepatocellular insufficiency and chronic liver disease, resulting in primary immunodeficiency and activation of the immune system following the possible expression of certain immunoreaction genes.

Maternal Acrylamide Intake during Pregnancy and Sex Hormone Levels in Maternal and Umbilical Cord Blood and Birth Size of Offspring.

Exposure to acrylamide during pregnancy may disturb pregnancy hormones and the growth of the fetus. The present study aimed to examine the association of maternal acrylamide intake with maternal and cord sex hormone levels during pregnancy and at birth and birth size of offspring. The study subjects were 204 pregnant Japanese women and their newborn girls. Intake of acrylamide was assessed based on 5-day diet records at approximately the 29th week of pregnancy. The concentrations of estradiol, estriol, and testosterone were measured in maternal serum at the 29th weeks of pregnancy and at delivery and umbilical cord blood at delivery. Birth weight, length, and head circumference were measured at the delivery. After controlling for covariates, higher intake of acrylamide was significantly positively associated with higher level of umbilical cord estradiol at the delivery (p for trend = .01), but not with any hormone levels measured in maternal blood. A positive association between acrylamide intake and head circumference was of borderline significance (p for trend = .06). Overall, there were no consistent associations between maternal acrylamide intake and sex hormone levels during pregnancy. However, as this is the first study to examine these associations, additional studies are needed.

Validity of Estimated Acrylamide Intake by the Dietary Record Method and Food Frequency Questionnaire in Comparison with a Duplicate Method: A Pilot Study.

Acrylamide, classified as a probable carcinogen to humans, forms during high- temperature cooking. Dietary exposure among the Japanese is unknown. To evaluate the validity of estimated acrylamide intake using a dietary record (DR) and the food frequency questionnaire (FFQ) in comparison with the duplicate diet method (DM) in a Japanese population. Design: A validation study was performed with 14 participants (age, 32-50 y; 11 women) from 11 households. Food samples were simultaneously collected for the DM and DR on the same day over 2 consecutive days. The FFQ was administered after collecting samples for the DM and DR. For the DM, dietary acrylamide was calculated from chemical analyses of each food. For the DR and FFQ, acrylamide intake for each food was calculated using the database of acrylamide contents of foods. Correlation coefficients were calculated using the Spearman rank method. Average acrylamide intake values calculated using the DM, DR, and FFQ were 0.106, 0.233, and 0.128 µg/kg body weight/d, respectively; these values showed a marginally positive correlation between the DM and DR (r=0.52), but a low correlation between the DM and FFQ (r=-0.011). For the DR, non-alcoholic drinks had the highest contribution, followed by confectionery and vegetables. For the DM, the contribution of confectionery was the highest, followed by vegetables and non-alcoholic drinks. In conclusion, the validity of acrylamide intake estimation using the DR was reasonably high when compared to the analytical value of the simultaneous DM. However, further improvement is required for estimating acrylamide intake using the FFQ.

Dose-dependent synergistic and antagonistic mutation responses of binary mixtures of the environmental carcinogen benzo[a]pyrene with food-derived carcinogens.

Cooking food at high temperatures produces genotoxic chemicals and there is concern about their impact on human health. DNA damage caused by individual chemicals has been investigated but few studies have examined the consequences of exposure to mixtures as found in food. The current study examined the mutagenic response to binary mixtures of benzo[a]pyrene (BaP) with glycidamide (GA), BaP with acrylamide (AC), or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) with GA at human-relevant concentrations (sub-nM). The metabolically competent human MCL-5 cells were exposed to these chemicals individually or in mixtures and mutagenicity was assessed at the thymidine kinase (TK) locus. Mixture exposures gave dose-responses that differed from those for the individual chemicals; for the BaP-containing mixtures, an increased mutation frequency (MF) at low concentration combinations that were not mutagenic individually, and decreased MF at higher concentration combinations, compared to the calculated predicted additive MF of the individual chemicals. In contrast, the mixture of PhIP with GA did not increase MF above background levels. These data suggest BaP is driving the mutation response and that metabolic activation plays a role; in mixtures with BaP the increased/decreased MF above/below the expected additive MF the order is PhIP > AC > GA. The increase in MF at some low concentration combinations that include BaP is interesting and supports our previous work showing a similar response for BaP with PhIP, confirming this response is not limited to the BaP/PhIP combination. Moreover, the lack of a mutation response for PhIP with GA relative to the response of the individual chemicals at equivalent doses is interesting and may represent a potential avenue for reducing the risk of exposure to environmental carcinogens; specifically, removal of BaP from the mixture may reduce the mutation effect, although in the context of food this would be significantly challenging.

Changes in VIP-, SP- and CGRP- like immunoreactivity in intramural neurons within the pig stomach following supplementation with low and high doses of acrylamide.

Acrylamide is one of the food toxins to which the human body is exposed. Although researchers' interest in acrylamide has been growing in recent years, the knowledge of its effect on the gastrointestinal tract, especially on intramural neurons which form the enteric nervous system is scarce. The aim of this experiment was to determine the influence of acrylamide, administered at doses equivalent to the human tolerable daily intake (TDI, 0.5 µg/kg b.w./day) and ten times higher than the TDI (5 µg/kg b.w./day), on the distribution of vasoactive intestinal peptide (VIP), substance P (SP), and calcitonin gene related peptide (CGRP) in intramural neurons of the domestic pig stomach. Using double immunofluorescent labelling we revealed that the ENS neurons underwent adaptive changes in response to the supplementation of acrylamide, which manifested themselves as increased expression of VIP, SP and CGRP, both in intramural neurons and by an increase in the nerve density in submucous and muscular layers in the porcine stomach. These substances take part in defensive reactions of neurons and transmission of sensory reactions may play an important role in protecting the stomach against the harmful effect of acrylamide. Moreover, it has been shown that acrylamide induces a significant response of ENS neurons even in TDI dose, which suggests that it is not neutral to the body. These findings may be the basis for further toxicological studies addressing the question if currently permitted minimal content of acrylamide in the food does jeopardize the health of human consumers?

Validity of a Self-administered Food Frequency Questionnaire for the Estimation of Acrylamide Intake in the Japanese Population: The JPHC FFQ Validation Study.

BACKGROUND: Acrylamide, a probable carcinogen to humans, forms during high temperature cooking. Dietary exposure to acrylamide among the Japanese population is unknown. We aimed to establish and validate a method to assess acrylamide exposure among the Japanese population using a food frequency questionnaire (FFQ) from the Japan Public Health Center-based prospective study. METHODS: Validation studies for the FFQ were conducted in 1994 (Cohort I, n = 215) and 1996 (Cohort II, n = 350). The 28-day dietary records (DRs) were collected over 1 year. The FFQ was distributed before and after DR collection. Data for acrylamide exposure were based on reported measurements in Japan, and calculations considered the cooking process for specific vegetables in a home setting. Spearman's rank correlation and weighted kappa coefficients were calculated from energy-adjusted data. RESULTS: Mean acrylamide intake levels estimated from DRs for Cohorts I and II were 6.78 (standard deviation [SD], 3.89) µg/day and 7.25 (SD, 3.33) µg/day, and corresponding levels estimated from the FFQ were 7.03 (SD, 4.30) µg/day and 7.14 (SD, 3.38) µg/day, respectively. Deattenuated correlation coefficients for men and women were 0.54 and 0.48 in Cohort I and 0.40 and 0.37 in Cohort II, respectively. Weighted kappa coefficients were over 0.80 in all cases. The main contributing food groups from DRs were beverages, confectioneries, vegetables, potatoes and starches, and cereals. CONCLUSIONS: High kappa values validate the use of FFQ in epidemiological studies. The marked contribution of cooked vegetables indicates the importance of considering household cooking methods in assessing acrylamide intake levels in the Japanese population.