Gestational acrylamide exposure and biomarkers of fetal growth: Probing the mechanism underlying the association between acrylamide and reduced fetal growth

Effect of post-gastrulation exposure to acrylamide on chick embryonic development

The critical developmental stages of the embryo are strongly influenced by the dietary composition of the mother. Acrylamide is a food contaminant that can form in carbohydrate-rich foods that are heat-treated. The aim of this study was to investigate the toxicity of a relatively low dose of acrylamide on the development of the neural tube in the early stage chick embryos. Specific pathogen-free fertilized eggs (n = 100) were treated with acrylamide (0.1, 0.5, 2.5, 12.5 mg/kg) between 28-30th hours of incubation and dissected at 48th hours. In addition to morphological and histopathological examinations, proliferating cell nuclear antigen (PCNA) and caspase 3 were analyzed immunohistochemically. The brain and reproductive expression gene (BRE) was analyzed by RT-PCR. Acrylamide exposure had a negative effect on neural tube status even at a very low dose (0.1 mg/kg) (p < 0.05). Doses of 0.5 mg/kg and above caused a delay in neural tube development (p < 0.05). Crown-rump length and somite count decreased dose-dependently, while this decrease was not significant in the very low dose group (p > 0.05), which was most pronounced at doses of 2.5 and 12.5 mg/kg (p < 0.001). Acrylamide exposure dose-dependently decreased PCNA and increased caspase 3, with this change being significant at doses of 0.5 mg/kg and above (p < 0.001). BRE was downregulated at all acrylamide exposures except in the very low dose group (0.1 mg/kg). In conclusion, we find that acrylamide exposure (at 0.5 mg/kg and above) in post-gastrulation delays neural tube closure in chicken embryos by suppressing proliferation and apoptosis induction and downregulating BRE gene expression.

Dietary Acrylamide: A Detailed Review on Formation, Detection, Mitigation, and Its Health Impacts

In today's fast-paced world, people increasingly rely on a variety of processed foods due to their busy lifestyles. The enhanced flavors, vibrant colors, and ease of accessibility at reasonable prices have made ready-to-eat foods the easiest and simplest choice to satiate hunger, especially those that undergo thermal processing. However, these foods often contain an unsaturated amide called 'Acrylamide', known by its chemical name 2-propenamide, which is a contaminant formed when a carbohydrate- or protein-rich food product is thermally processed at more than 120 °C through methods like frying, baking, or roasting. Consuming foods with elevated levels of acrylamide can induce harmful toxicity such as neurotoxicity, hepatoxicity, cardiovascular toxicity, reproductive toxicity, and prenatal and postnatal toxicity. This review delves into the major pathways and factors influencing acrylamide formation in food, discusses its adverse effects on human health, and explores recent techniques for the detection and mitigation of acrylamide in food. This review could be of interest to a wide audience in the food industry that manufactures processed foods. A multi-faceted strategy is necessary to identify and resolve the factors responsible for the browning of food, ensure safety standards, and preserve essential food quality traits.

Effects of acrylamide exposure during pregnancy and lactation on the development of myelin sheath of corpus callosum in offspring rats

Acrylamide is an alkene known to induce neurotoxicity in humans and experimental animals. However, the effects of acrylamide on the development of myelin sheath are unclear. The present study was to explore the effects of acrylamide exposure during pregnancy and lactation on the development of myelin sheath in offspring rats. Four groups of thirty-two pregnant Sprague-Dawley rats were exposed to 0, 4.5, 9 and 18 mg/kg BW acrylamide by gavage from gestational day 15 to postnatal day 13. The corpus callosum of nine offspring rats per group were dissected in postpartum day 14. Structural changes and lipid contents in myelin sheaths were examined by transmission electron microscopy(TEM) and Luxol Fast Blue staining(LFB). The expression of MBP and PLP was evaluated by immunohistochemistry and Western blotting. TEM showed that the myelin sheaths in the 18 mg/kg group were disordered compared with control group. Luxol Fast Blue staining gradually decreased with increasing acrylamide maternal exposure. The immunohistochemistry and Western Blotting results showed that maternal exposure to acrylamide caused a decreasing trend in MBP and PLP in the corpus callosum of rats at postnatal day 14. Furthermore, these reduced protein levels may be neurodevelopmental toxicity's mechanism in response to maternal exposure to acrylamide.

Brain-derived neurotrophic factor (BDNF): an effect biomarker of neurodevelopment in human biomonitoring programs

The present narrative review summarizes recent findings focusing on the role of brain-derived neurotrophic factor (BDNF) as a biomarker of effect for neurodevelopmental alterations during adolescence, based on health effects of exposure to environmental chemical pollutants. To this end, information was gathered from the PubMed database and the results obtained in the European project Human Biomonitoring for Europe (HBM4EU), in which BDNF was measured at two levels of biological organization: total BDNF protein (serum) and BDNF gene DNA methylation (whole blood) levels. The obtained information is organized as follows. First, human biomonitoring, biomarkers of effect and the current state of the art on neurodevelopmental alterations in the population are presented. Second, BDNF secretion and mechanisms of action are briefly explained. Third, previous studies using BDNF as an effect biomarker were consulted in PubMed database and summarized. Finally, the impact of bisphenol A (BPA), metals, and non-persistent pesticide metabolites on BDNF secretion patterns and its mediation role with behavioral outcomes are addressed and discussed. These findings were obtained from three pilot studies conducted in HBM4EU project. Published findings suggested that exposure to some chemical pollutants such as fine particle matter (PM), PFAS, heavy metals, bisphenols, and non-persistent pesticides may alter circulating BDNF levels in healthy population. Therefore, BDNF could be used as a valuable effect biomarker to investigate developmental neurotoxicity of some chemical pollutants.

Dietary acrylamide and incident osteoporotic fractures: an 8-year prospective cohort study

BACKGROUND

Acrylamide, a component of fried foods, has been associated with several negative health outcomes. However, the relationship between dietary acrylamide and osteoporotic fractures has been explored by a few cross-sectional studies.

AIMS

To investigate if dietary acrylamide is associated with the onset of fractures in North American participants at high risk/having knee osteoarthritis (OA), over 8 years of follow-up.

METHODS

A Cox's regression analysis, adjusted for baseline confounders was run and the data were reported as hazard ratios (HRs) and 95% confidence intervals (CIs). Dietary acrylamide intake was assessed at the baseline using a food frequency questionnaire and categorized in tertiles (T), whilst fractures' history was recorded using self-reported information.

RESULTS

Altogether, 4,436 participants were included. Compared to participants with lower acrylamide intake (T1; < 3,313 μg), those with a higher acrylamide intake (T3; > 10,180 μg) reported a significantly higher risk of any fracture (HR = 1.37; 95% CI 1.12-1.68; p for trend = 0.009), forearm (HR = 1.73; 95% CI 1.09-2.77; p for trend = 0.04), spine (HR = 2.21; 95% CI 1.14-4.31; p for trend = 0.04), and hip fracture (HR = 4.09; 95% CI 1.29-12.96; p for trend = 0.046).

CONCLUSIONS

Our study is the first to report that high dietary acrylamide may be associated with an increased risk of osteoporotic fractures.

Association between acrylamide exposure and the odds of developmental disabilities in children: A cross-sectional study

Background

The association between acrylamide exposure and the odds of developmental disabilities (DDs) is unclear. We conducted this analysis to explore whether acrylamide exposure is related to DDs.

Methods

We analyzed a sample of 1,140 children aged 6-17 years old from the US National Health and Nutrition Examination Survey 2013-2014 to 2015-2016. DDs were determined by reports of parents. Acrylamide exposure was evaluated by the hemoglobin adducts of acrylamide (HbAA) and its major metabolite glycidamide (HbGA). We investigated the association using binomial logistic regression analysis by taking HbAA and HbGA as continuous or quartile variables. Restricted cubic splines (RCS) were used to explore the non-linear relationship between HbAA or HbGA and the odds of DDs. Interaction analysis and propensity score matching (PSM) were used to validate the results.

Results

A total of 134 participants were reported to have DDs. The median level of HbAA and HbGA was 41.6 and 40.5 pmol/g Hb, respectively. HbAA and HbGA were not associated with the odds of DDs when taken as continuous variables. When divided into quartiles, there was no evidence for a linear trend for HbAA and HbGA. RCS showed that there was a J-shaped association between HbGA and the odds of DDs (P for non-linearity, 0.023). The results were consistent in interaction analysis by age, gender, and race, and after PSM.

Conclusion

HbGA level was associated with the odds of DDs in a J-shaped manner among children. Further investigation is warranted to determine the causality and underlying mechanisms.

Allicin Promoted Reducing Effect of Garlic Powder through Acrylamide Formation Stage

Background: Acrylamide is formed during food heating and is neurotoxic to animals and potentially carcinogenic to humans. It is important to reduce acrylamide content during food processing. Researchers have suggested that garlic powder could reduce acrylamide content, but the key substance and acrylamide reduction pathway of garlic powder was unclear. Methods: The inhibitory effect of garlic powder on acrylamide in asparagine/glucose solution and a fried potato model system were firstly evaluated. Furthermore, the effect of allicin on the amount of produced acrylamide in the asparagine/glucose solution model system and fried potatoes was studied with kinetic analysis. Results: The freeze-dried garlic powder had a higher inhibition rate (41.0%) than oven-dried garlic powder (maximum inhibition rate was 37.3%), and allicin had a 71.3% attribution to the reduction of acrylamide content. Moreover, the inhibition rate of allicin had a nonlinear relationship with the addition level increase. The kinetic analysis indicated that garlic powder and allicin could reduce acrylamide content through the AA formation stage, but not the decomposition stage. Conclusions: Allicin was the key component of garlic powder in reducing acrylamide content during acrylamide formation stage. This research could provide a new method to reduce acrylamide content during food processing and expand the application area of garlic.

Acrylamide and Potential Risk of Diabetes Mellitus: Effects on Human Population, Glucose Metabolism and Beta-Cell Toxicity

Diabetes mellitus is a frequent endocrine disorder characterized by hyperglycemia. Acrylamide (AA) is food contaminant formed during the high-temperature processing of food rich in carbohydrates and low in proteins. Recent human epidemiological studies have shown a potential association between AA exposure and the prevalence of diabetes in the general population. In male rats, AA treatment promoted pancreatic islet remodeling, which was determined by alpha-cell expansion and beta-cell reduction, while in female rats AA caused hyperglycemia and histopathological changes in pancreatic islets. In vitro and in vivo rodent model systems have revealed that AA induces oxidative stress in beta cells and that AA impairs glucose metabolism and the insulin signaling pathway. Animal studies have shown that diabetic rodents are more sensitive to acrylamide and that AA aggravates the diabetic state. In this review, we provide an overview of human epidemiological studies that examined the relation between AA exposure and glucose disorders. In addition, the effects of AA treatment on pancreatic islet structure, beta-cell function and glucose metabolism in animal models are comprehensively analyzed with an emphasis on sex-related responses. Furthermore, oxidative stress as a putative mechanism of AA-induced toxicity in beta cells is explored. Finally, we discuss the effects of AA on diabetics in a rodent model system.

Acrylamide Exposure Destroys the Distribution and Functions of Organelles in Mouse Oocytes

Acrylamide (ACR) is a common industrial ingredient which is also found in foods that are cooked at high temperatures. ACR has been shown to have multiple toxicities including reproductive toxicity. Previous studies reported that ACR caused oocyte maturation defects through the induction of apoptosis and oxidative stress. In the present study, we showed that ACR exposure affected oocyte organelle functions, which might be the reason for oocyte toxicity. We found that exposure to 5 mM ACR reduced oocyte maturation. ACR caused abnormal mitochondrial distribution away from spindle periphery and reduced mitochondrial membrane potential. Further analysis showed that ACR exposure reduced the fluorescence intensity of Rps3 and abnormal distribution of the endoplasmic reticulum, indicating that ACR affected protein synthesis and modification in mouse oocytes. We found the negative effects of ACR on the distribution of the Golgi apparatus; in addition, fluorescence intensity of vesicle transporter Rab8A decreased, suggesting the decrease in protein transport capacity of oocytes. Furthermore, the simultaneous increase in lysosomes and LAMP2 fluorescence intensity was also observed, suggesting that ACR affected protein degradation in oocytes. In conclusion, our results indicated that ACR exposure disrupted the distribution and functions of organelles, which further affected oocyte developmental competence in mice.

Hemoglobin adducts of acrylamide in human blood - What has been done and what is next?

Acrylamide forms in many commonly consumed foods. In animals, acrylamide causes tumors, neurotoxicity, developmental and reproductive effects. Acrylamide crosses the placenta and has been associated with restriction of intrauterine growth and certain cancers. The impact on human health is poorly understood and it is impossible to say what level of dietary exposure to acrylamide can be deemed safe as the assessment of exposure is uncertain. The determination of hemoglobin (Hb) adducts from acrylamide is increasingly being used to improve the exposure assessment of acrylamide. We aim to outline the literature on Hb adduct levels from acrylamide in humans and discuss methodological issues and research gaps. A total of 86 studies of 27,966 individuals from 19 countries were reviewed. Adduct levels were highest in occupationally exposed individuals and smokers. Levels ranged widely from 3 to 210 pmol/g Hb in non-smokers and this wide range suggests that dietary exposure to acrylamide varies largely. Non-smokers from the US and Canada had slightly higher levels as compared with non-smokers from elsewhere, but differences within studies were larger than between studies. Large studies with exposure assessment of acrylamide and related adduct forming compounds from diet during early-life are encouraged for the evaluation of health effects.

Gestational exposure to acrylamide suppresses luteal endocrine function through dysregulation of ovarian angiogenesis, oxidative stress and apoptosis in mice

The discovery of acrylamide in various carbohydrate-rich foods cooked at high temperatures has attracted public health concerns. This study aimed to elucidate the effects and mechanisms additional with acrylamide exposure on the luteal function in vivo during early- and mid-pregnancy. Mice were fed with different dosages of acrylamide (0, 10 and 50 mg/kg/day) by gavage from gestational days (GD) 3 to GD 8 or GD 13. The results indicated that acrylamide exposure significantly decreased levels of serum progesterone and estradiol, and the numbers and relative areas of ovarian corpora lutea. The expression levels of Hsd3b1, Cyp11a1 and Star mRNA markedly reduced in acrylamide-treated ovaries. Furthermore, acrylamide exposure obviously suppressed the activities of catalase and superoxide dismutase, but increased the levels of H₂O₂ and malondialdehyde. Additionally, acrylamide treatment significantly inhibited luteal angiogenesis and induced the apoptosis of ovarian cells by up-regulation of P53 and Bax protein and down-regulation of Bcl-2 protein. Thus, our results showed that gestational exposure to acrylamide significantly inhibited luteal endocrine function via dysregulation of ovarian angiogenesis, oxidative stress and apoptosis in vivo.