Acrylamide-induced mitochondria collapse and apoptosis in human astrocytoma cells

Parental exposure to acrylamide disrupts sphingolipid metabolism and impairs transgenerational neurodevelopment in zebrafish (Danio rerio) offspring

Acrylamide exposure has become an emerging environmental and food safety issue, and its toxicity poses a potential threat to public health worldwide. However, limited studies have paid attention to the detrimental effects of parental exposure to acrylamide on the neurodevelopment in zebrafish offspring. In this study, the embryos were life-cycle exposed to acrylamide (0.125 and 0.25 mM) for 180 days. Subsequently, these zebrafish (F0) were allowed to mate, and their offspring (F1) were collected to culture in clean water from embryos to adults. We employed developmental and morphological observations, behavioral profiles, metabolomics analyses, and transcriptional level examinations to investigate the transgenerational neurotoxicity with parental exposure to acrylamide. Our results showed that parental exposure to acrylamide harms the birth, development, and behavior characterization of the F1 zebrafish larvae, including poor egg quality, increased mortality rates, abnormal heart rates, slowed swimming activity, and heightened anxiety behavior, and continuously disturbs mental health in F1 adult zebrafish. The transcriptional analysis showed that parental chronic exposure to acrylamide deteriorates the neurodevelopment in F1 larvae. In addition, metabolomics analyses revealed that sphingolipid metabolism disruption may be associated with the observed abnormal development and behavioral response in unexposed F1 offspring. Overall, the present study provides pioneer evidence that acrylamide induces transgenerational neurotoxicity via targeting and disrupting sphingolipid metabolism, which reveals intergenerational transmission of acrylamide exposure and unravels its spatiotemporal toxicological effect on neurodevelopment.

Pulmonary damage induction upon Acrylic amide exposure via activating miRNA-223-3p and miRNA-325-3p inflammasome/pyroptosis and fibrosis signaling pathway: New mechanistic approaches of A green-synthesized extract

Exposure to acrylic amide (AD) has garnered worldwide attention due to its potential adverse health effects, prompting calls from the World Health Organization for intensified research into associated risks. Despite this, the relationship between oral acrylic amide (acrylamide) (AD) exposure and pulmonary dysfunction remains poorly understood. Our study aimed to investigate the correlation between internal oral exposure to AD and the decline in lung function, while exploring potential mediating factors such as tissue inflammation, oxidative stress, pyroptosis, and apoptosis. Additionally, we aimed to evaluate the potential protective effect of zinc oxide nanoparticles green-synthesized moringa extract (ZNO-MONPs) (10 mg/kg b.wt) against ACR toxicity and conducted comprehensive miRNA expression profiling to uncover novel targets and mechanisms of AD toxicity (miRNA 223-3 P and miRNA 325-3 P). Furthermore, we employed computational techniques to predict the interactions between acrylic amide and/or MO-extract components and tissue proteins. Using a rat model, we exposed animals to oral acrylamide (20 mg/kg b.wt for 2 months). Our findings revealed that AD significantly downregulated the expression of miRNA 223-3 P and miRNA 325-3 P, targeting NLRP-3 & GSDMD, respectively, indicating the induction of pyroptosis in pulmonary tissue via an inflammasome activating pathway. Moreover, AD exposure resulted in lipid peroxidative damage and reduced levels of GPX, CAT, GSH, and GSSG. Notably, AD exposure upregulated apoptotic, pyroptotic, and inflammatory genes, accompanied by histopathological damage in lung tissue. Immunohistochemical and immunofluorescence techniques detected elevated levels of indicative harmful proteins including vimentin and 4HNE. Conversely, concurrent administration of ZNO-MONPs with AD significantly elevated the expression of miRNA 223-3 P and miRNA 325-3 P, protecting against oxidative stress, apoptosis, pyroptosis, inflammation, and fibrosis in rat lungs. In conclusion, our study highlights the efficacy of ZNO-MONPs NPs in protecting pulmonary tissue against the detrimental impacts of foodborne toxin AD.

Mechanism of apoptosis induced by the combined action of acrylamide and Elaidic acid through endoplasmic reticulum stress injury

Thermal processing of food is likely to form acrylamide (AA) and elaidic acid (EA), which are both mainly metabolized by the liver. The two substances are associated with the pathogenesis of liver disease. In the current study, we investigated the toxic effects of the combined action of AA and EA on HSC-T6 cells, and the mechanism of apoptosis exacerbated by the co-exposure. The results showed a synergistic effect of AA and EA, which exacerbated the damage and oxidative stress (OS) in HSC-T6. Meanwhile, the expression of endoplasmic reticulum stress (ERS) proteins, such as GRP78 and CHOP, was increased, the ERS pathway was activated, and Ca2+ in cells was increased, which exacerbated mitochondrial damage, and opened IP3R-Grp75-VDAC1 channel. Both ERS and mitochondrial damage caused the process of cell apoptosis. Inhibition of ERS by 4-phenylbutyric acid (4-PBA) significantly reversed the synergistic effects on mitochondrial damage via ERS, suggesting that AA and EA exacerbated mitochondrial damage through ERS-mediated Ca2+ overload. AA and EA synergistically damaged the function of mitochondria through exacerbating ERS and led to cell apoptosis.

Protective effects of vitamin E against acrylamide-induced hepatotoxicity and nephrotoxicity from fetal development to adulthood: Insights into Akt/NF-κB and Bcl-xL/Bax signaling pathways

Acrylamide (ACR), a toxin present in fried and baked carbohydrate-rich foods, is known to cause liver and kidney damage. This study aimed to investigate the mechanisms of oxidative stress, inflammation, and apoptosis that contribute to liver and kidney damage induced by chronic administration of ACR. Additionally, the effectiveness of vitamin E in mitigating these toxic effects was examined. The study initially involved dividing 40 pregnant rats into four groups. After lactation, the research continued with male offspring rats from each group. The offspring rats were divided into Control, Vitamin E, ACR, and ACR + Vitamin E groups. Following ACR administration, liver and kidney function tests were performed on serum samples. Biochemical analyses, evaluation of inflammation markers, histopathological examination, and assessment of protein levels of Akt/IκBα/NF-κB, Bax, Bcl-xL, and Caspase-9 were conducted on liver and kidney tissues. The analysis demonstrated that ACR adversely affected liver and kidney function, resulting in oxidative stress, increased inflammation, and elevated apoptotic markers. Conversely, administration of vitamin E positively impacted these parameters, restoring them to control levels. Based on the results, the mechanism of ACR's action on oxidative stress and inflammation-induced liver and kidney damage may be associated with the activation of apoptotic markers such as Bax and Caspase-9, as well as the Akt/IκBα/NF-κB signaling pathway. Consequently, the protective properties of vitamin E establish it as an essential vitamin for the prevention or mitigation of various ACR-induced damages.

Acrylamide induces neurotoxicity in zebrafish (Danio rerio) via NLRP3-mediated pyroptosis

Acrylamide (ACR) is widely used in water treatment, cosmetics, dyes, paper manufacturing, and other industries. Evidence suggests that ACR exposure causes selective neurotoxicity in humans. The primary symptoms include extremity numbness, skeletal muscle weakness, and ataxia, skeletal muscle weakness. An experimental zebrafish (Danio rerio) embryo model was used in this study to assess the impact of ACR toxicity on the development of the zebrafish nervous system. The results showed that neurodevelopmental disorders, inflammatory reactions, and oxidative stress were common in zebrafish exposed to ACR. Furthermore, ACR exposure induces pyroptotic phenotypical nerve cells, pyroptosis-related protein activation, and inflammasome NLR family pyrin domain-containing 3 (NLRP3) expression. Caspy and Caspy2 expression was knocked down via CRISPR/Cas9 to further investigate the pyroptotic mechanism, showing that these two targets alleviated the inflammatory reaction and neurodevelopmental disorder caused by ACR. Moreover, the Caspy-mediated classic pathway may be vital for the pyroptosis caused by ACR. In conclusion, this study is the first to show that ACR can activate NLRP3 inflammation to cause neurotoxicity in zebrafish via the Caspy pathways, which differs from the traditional exogenous infection model.

Dynamic assessment of the relationship between oxidative stress and apoptotic pathway in embryonic fibroblast cells exposed to glycidamide: possible protective role of hesperidin

Worldwide research is being conducted to determine the level of acrylamide (ACR) that humans are exposed to from food and environmental sources. Glycidamide (GA) is an important epoxide metabolite of ACR, and its cytotoxicity is stronger than ACR. In this study, it was aimed to elucidate the effects and underlying mechanisms of GA on the induction of apoptosis in embryonic fibroblast cells. The toxicogenomic profile of GA was studied in terms of both apoptotic and oxidative stress. Embryonic fibroblast cells were exposed to GA (1 and 1000 µM) in the presence and absence of hesperidin (Hes) (20 µM) or vitamin C (VitC) (50 µM) for 24 h. Cell viability, cytotoxicity, lipid peroxidation, hydroxyl radicals, hydrogen peroxide, antioxidant enzyme levels and gene expressions, apoptotic, and oxidative stress-related gene expressions were measured in embryonic fibroblast cells. The results showed that GA induced cytotoxicity and diminished the expression levels of apoptotic genes. Furthermore, GA increased the levels of oxidative stress markers and significantly changed the oxidative stress-related gene expression. It has been determined that antioxidant molecules are considerably suppressed in GA-induced toxicity at both gene and enzyme levels. In addition to these results, when VitC, which is known to have strong antioxidant properties in eliminating the toxic effects of GA, is taken as reference, it has been proven that Hes has stronger antioxidant properties compared to VitC. Finally, GA-induced apoptosis in embryonic fibroblast cells is associated with nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent oxidative stress and Hes has antioxidant properties with strong effects.

Research Progress of Programmed Cell Death Induced by Acrylamide

Acrylamide exposure through environment pollution and diet is very common in daily life. With the deepening of the study on the toxicity of acrylamide, it has attracted widespread attention for the effects of acrylamide on multiple organs through affecting a variety of programmed cell death. Multiple studies have shown that acrylamide could exert its toxic effect by inducing programmed cell death, but its specific molecular mechanism is still unclear. In this review, the research on the main forms of programmed cell death (apoptosis, autophagy, and programmed necrosis) induced by acrylamide and their possible mechanisms are reviewed. This review may provide basic data for further research of acrylamide and prevention of its toxicity.

Acrylamide, acrylic acid, or 2-acrylamido-2-methyl-1-propanesulfonic acid induced cytotoxic in Photobacterium phosphoreum, PC12, and SK-N-SH cells

In enhancing oil recovery, more and more new water-soluble polymers are developed to replace the high toxicity and low stability acrylamide (ACR) monomer. The common replacement monomer is acrylic acid (AA) and 2-acrylamido-2-methylamido-2-methyl-1-propanesulfonic acid (AMPS), which are considered safe and efficient. In this study, AA, ACR and AMPS caused remarkable cytotoxicity in Photobacterium phosphoreum, the rat pheochromocytoma cells (PC12) and the Human neuroblastoma cells (SK-N-SH). ACR is much more lethal than AA and AMPS in PC12 and SK-N-SH cells, meanwhile, the toxicity of AA and AMPS decreases with the decrease of acid. Furthermore, similar to ACR, AA, and AMPS can induce severe DNA double-strand breakage in PC12 and SK-N-SH cells. Both AA and ACR can cause cell cycle arrest in the G0/G1 phase in PC12 and SK-N-SH cells. In addition, like ACR, AA, and AMPS can generate reactive oxygen species (ROS) accumulation, mitochondrial dysfunction and mitochondrial-dependent apoptosis in both PC12 and SK-N-SH cells. The acute toxicity of AA and AMPS is lower than ACR, however, the decline in acute toxicity in monomers does not mean toxic-free. We should focus on the toxicity of AA and ACR and reduce occupational contact to protect employee occupational health.

Effects of naringin on oxidative stress, inflammation, some reproductive parameters, and apoptosis in acrylamide-induced testis toxicity in rat

Acrylamide (ACR) is used in many fields such as cosmetics, paper, and textile industries. It also occurs at very high temperatures in some foods. Gonadotoxic effects of ACR have been found in experimental animals. Many studies use flavonoids to prevent the reproductive side effects of ACR. Naringin (NA) is a flavonoid and it has been determined by studies that it has no toxic effect on tissues. In our study, we aimed to determine the protective effect of NA against the damage of ACR on testicular tissue and the reproductive system in rats. In our study, 50 Spraque Dawley male rats weighing 220-250 grams were used. Control: Only intragastric saline was administered for 10 days. ACR: Animals received ACR (40 mg/kg, intraperitoneally) for 10 days. NA50+ACR: Animals were given NA for 10 days and each NA was one hour after the administration of ACR. NA100+ACR: Animals received NA for 10 days and one hour after each NA was given ACR. NA100: Animals were given NA for 10 days. At the end of the applications, the rats were euthanized by cervical dislocation under anesthesia. Serum FSH, LH, and Dihydrotestosterone levels were compared between the groups. In addition, oxidative stress, inflammation, expression of some reproductive enzymes, and apoptosis markers were determined in testicular tissues. When these parameters were compared between groups, ACR induced testicular dysfunction and tissue damage in rats. We determined that only the NA application did not cause tissue damage. and the administration of NA along with ACR significantly reduced ACR-induced testis toxicity.

Exposure to acrylamide inhibits testosterone production in mice testes and Leydig cells by activating ERK1/2 phosphorylation

Acrylamide (ACR) is formed during the cooking of starchy foods at high temperatures. Accumulating evidence has shown that ACR has toxic effects, but the mechanism of its potential reproductive toxicity remains unclear. In this study, we observed that ACR caused weight loss in mice. There was no significant difference in the weight of testis and epididymis between the low/medium-dose ACR group and the control group. And the number of epididymal sperms, testicular Leydig cells, serum testosterone level, testicular steroidogenic genes and enzymes, including cytochrome P450 family 11 subfamily A member 1 (CYP11A1) and cytochrome P450 family 17 subfamily A member 1 (CYP17A1), were decreased in the medium/high-dose ACR group. Additional cell experiments showed that the apoptosis rate and the level of reactive oxygen species (ROS) were increased, and testosterone levels and CYP17A1 protein expression were reduced in Leydig cells with treated ACR. Furthermore, the phosphorylation levels of extracellular signal-regulated kinases (ERK1/2) increased significantly; however, there was no significant difference in the levels of serine-threonine protein kinase (AKT) phosphorylation in the testis of mice and Leydig cells treated with ACR. These results suggest that ACR exposure leads to the damage of testicular structure and function and a decline in testosterone synthesis in Leydig cells and mouse testis, which may be related to the activated phosphorylation of ERK1/2.

Palliative effect of Moringa olifera-mediated zinc oxide nanoparticles against acrylamide-induced neurotoxicity in rats

Repeated acrylamide (ACR) exposure in experimental animals and humans causes variable degrees of neuronal damage. Because of its unique features, several green synthesized nanomaterials are explored for neuromodulatory activity. Hence, this study investigated the effect of green synthesized zinc oxide nanoparticles using Moriga olifera leaves extract (MO-ZnONP) against acrylamide (ACR)-induced neurobehavioral and neurotoxic impacts in rat. Forty male Sprague Dawley rats were distributed into four groups orally given distilled water, MO-ZnONP (10 mg/kg b.wt), ACR (20 mg/kg b.wt), or MO-ZnONP + ACR for 60 days. Gait quality and muscular, motor, and sensory function were assessed. Acetylcholinesterase (AChE), dopamine, catalase, malondialdehyde (MDA), and Zn brain contents were determined. Brain histopathology and immunohistochemical localization of the amyloid-β protein and abnormal Tau were performed. The results revealed that MO-ZnONP significantly reduced ACR-induced sensory dysfunctions, hind limb abnormality, and motor deficits. Additionally, the ACR-induced increase in dopamine and AChE were significantly supressed by MO-ZnONP. Besides, MO-ZnONP significantly restored catalase and Zn content but reduced increased MDA brain content resulting from ACR. Furthermore, the ACR-induced neurodegenerative changes and increased amyloid-β and phosphorylated Tau immunoexpression was significantly abolished by MO-ZnONP. Conclusively, MO-ZnONP could be used as a biologically effective compound for mitigating ACR's neurotoxic and neurobehavioral effects.

The role of Bax/Bcl-2 and Nrf2-Keap-1 signaling pathways in mediating the protective effect of boric acid on acrylamide-induced acute liver injury in rats

INTRODUCTION

This study aims to investigate whether boric acid (BA) can protect rats from acrylamide (AA)-induced acute liver injury.

MATERIALS AND METHODS

AA was used to induce acute liver injury. Thirty rats were divided into five group including Group 1 (saline), Group 2 (AA), Group 3 (20 mg/kg BA), Group 4 (10 mg/kg BA+AA) and Group 5 (20 mg/kg BA+AA). Their blood and liver were harvested to be kept for analysis. Liver function enzyme activities were performed by spectrophotometric method. Catalase (CAT), superoxide dismutase (SOD) activity, and malondialdehyde levels were determined by colorimetric method. The in-silico studies were performed using the "blind docking" method.

RESULTS

Administration AA to rats, biochemical parameters, liver histology, and expression levels of apoptotic markers were negatively affected. However, after the administration of BA, the altered biochemical parameters, liver histology, and expression levels of apoptotic markers were reversed. Moreover, the mechanisms of AA-induced deterioration in the levels of SOD, CAT, and Nrf2-Keap-1 and the mechanisms of the protective effect of BA against these deteriorations were explained by in silico studies.

CONCLUSION

Thus, the present study could explain the interactions between AA and thiol-containing amino acid residues of Keap-1, the effect of BA on these interactions, and the biochemical toxicity caused by the AA. In this sense, this work is the first of its kind in the literature. Based on the biochemical, histopathological, and in silico results, it can be suggested that BA has the potential to be used as a protective agent against AA-induced liver injury.

Pharmacotherapeutic potential of pomegranate in age-related neurological disorders

Age-related neurological disorders [AND] include neurodegenerative diseases [NDDs] such as Alzheimer's disease [AD] and Parkinson's disease [PD], which are the most prevalent types of dementia in the elderly. It also includes other illnesses such as migraine and epilepsy. ANDs are multifactorial, but aging is their major risk factor. The most frequent and vital pathological features of AND are oxidative stress, inflammation, and accumulation of misfolded proteins. As AND brain damage is a significant public health burden and its incidence is increasing, much has been done to overcome it. Pomegranate (Punica granatum L.) is one of the polyphenol-rich fruits that is widely mentioned in medical folklore. Pomegranate is commonly used to treat common disorders such as diarrhea, abdominal pain, wound healing, bleeding, dysentery, acidosis, microbial infections, infectious and noninfectious respiratory diseases, and neurological disorders. In the current review article, we aimed to summarize the data on the pharmacotherapeutic potentials of pomegranate in ANDs.

Neuroprotection by melatonin against acrylamide-induced brain damage in pinealectomized rats

The current study aimed to evaluate the neuroprotective effect of exogenous melatonin against acrylamide (ACR)-induced oxidative stress and inflammatory and apoptotic responses in the brain tissues in pinealectomized rats (PINX). ACR is a toxic chemical carcinogen that occurs owing to the preparation of carbohydrate-rich foods at high temperatures or other thermal processes. The rats who underwent pinealectomy and sham pinealectomy were exposed to ACR (25 mg/kg b.w., orally) alone or with exogenous melatonin (10 mg/kg b.w., i.p.) for 21 consecutive days. Alterations of brain oxidant/antioxidant status, dopamine (DA), Brain-Derived Neurotropic Factor (BDNF) inflammatory mediator and apoptosis during exposure to ACR in pinealectomized rats were more than without pinealectomized rats. Histopathological changes were more in brain tissue of pinealectomized rats after ACR administration. Exogenous melatonin treatment in ACR -exposed rats following pinealectomy increased the activities of antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) and improved brain total antioxidant status (TAS) compared to PINX+ACR. Moreover, melatonin suppressed lipid peroxidation, inflammatory pathways and apoptosis in ACR-intoxicated brain tissues. In addition, after exposure to ACR on pinealectomized rats, melatonin treatment ameliorated BDNF and DA levels in brain tissues. Furthermore, exogenous melatonin intervention in ACR-intoxicated rats significantly rescued the architecture of neuronal tissues. In summary, the present study, for the first time, suggested that exogenous melatonin treatment could reduce oxidative damage by increasing the activities of antioxidant enzymes, inhibiting lipid peroxidation and inflammation, and improving histopathological alterations in the brain tissue of pinealectomized rats after ACR administration.

The involvement of oxidative stress, neuronal lesions, neurotransmission impairment, and neuroinflammation in acrylamide-induced neurotoxicity in C57/BL6 mice

Acrylamide (ACR) is a typical environmental contaminant, presenting potential health hazards that have been attracting increasing attention. Its neurotoxicity is known to cause significant damage to health. However, the mechanisms of ACR-induced neurotoxicity require further clarification. This study uses a mouse model to explore how ACR-induced oxidative stress, neuronal lesions, neurotransmission impairment, and neuroinflammation mutually contribute to neurotoxicity. A distinct increase in the cellular reactive oxygen species (ROS) levels, malondialdehyde (MDA), and 8-hydroxy-2-deoxyguanosine (8-OHdG) content and a significant decrease in the glutathione (GSH) content after ACR exposure were indicative of oxidative stress. Moreover, ACR caused neurological defects associated with gait abnormality and neuronal loss while suppressing the acetylcholine (ACh) and dopamine (DA) levels and increasing the protein expression of α-synuclein (α-syn), further inhibiting cholinergic and dopaminergic neuronal function. Additionally, ACR treatment caused an inflammatory response via nuclear factor-kappa B (NF-κB) activation and increased the protein expression of NOD-like receptor protein-3 (NLRP3), consequently activating the NLRP3 inflammasome constituents, including cysteinyl aspartate specific proteinase 1 (Caspase-1), apoptosis-associated speck-like protein containing CARD (ASC), N domain gasdermin D (N-GSDMD), interleukin-1β (IL-1β), and IL-18. The results revealed the underlying molecular mechanism of ACR-induced neurotoxicity via oxidative stress, neurotransmission impairment, and neuroinflammation-related signal cascade. This information will further improve the development of an alternative pathway strategy for investigating the risk posed by ACR. The hypothetical mechanism of ACR-induced neurotoxicity in vivo.

Effect of Dietary Exposure to Acrylamide on Diabetes-Associated Cognitive Dysfunction from the Perspectives of Oxidative Damage, Neuroinflammation, and Metabolic Disorders

Acrylamide is a toxic compound that is produced widely during food processing, but whether the daily dietary consumption of acrylamide can impair the cognitive dysfunction in diabetic individuals and the potential underlying mechanisms are unknown. The aim of the present study was to observe the changes in cognitive and memory performance caused by chronic acrylamide exposure and to evaluate its influence on the brain morphology, oxidative damage, neuroinflammation, and brain metabolic disturbance. Goto-Kakizaki (GK) rats, a rat model of diabetes, were orally administered acrylamide at 1 mg/kg body weight for 8 weeks. The results of the novel object recognition and Y-maze tests showed that the consumption of acrylamide significantly aggravated diabetes-associated cognitive dysfunction in GK rats. Acrylamide increased reactive oxygen species and malondialdehyde formation and reduced glutathione levels, catalase, and total antioxidant capacity activity, which caused a succession of events associated with oxidative damage, including glial cell activation. After the activation of astrocytes and microglia, related cytokines, including interleukin-1β, interleukin-6, tumor necrosis factor-α, and lipopolysaccharide, were released, amyloid β-protein was accumulated, brain-derived neurotrophic factor was decreased, and the expression of caspase-3 and caspase-9 was increased, which aggravated neuroinflammation. Furthermore, there was perturbation of some important metabolites, including glutamic acid, citric acid, pyruvic acid, lactate, and sphinganine, and their related glucose, amino acid, and energy metabolism pathways in the brain. This work helps to demonstrate the effect of consumption of acrylamide in the daily diet on diabetes-associated cognitive dysfunction and its underlying mechanisms.

MiR-27a-5p regulates acrylamide-induced mitochondrial dysfunction and intrinsic apoptosis via targeting Btf3 in rats

Acrylamide (AA), a potential carcinogen, is commonly formed in foods rich in carbohydrates at high heat. It is known that AA-induced mitochondrial dysfunction is responsible for its toxicity. Previously we found AA exposure increased miR-27a-5p expression in livers of SD rats. Here, the regulation mechanism of miR-27a-5p in mitochondrial dysfunction was investigated in rat liver cell lines (IAR20) and SD rats. The results showed that the overexpressed miR-27a-5p contributes to modulating mitochondrial dysfunction and Btf3 is identified as its target gene. The knockdown of Btf3 increases the cleaved PARP1 level and the phosphorylation of ATM and p53, which results in mitochondria-dependent apoptosis. Therefore, the miR-27a-5p-Btf3-ATM-p53 axis might play a vital role in the promotion of AA-induced cell apoptosis through disrupting mitochondrial structure and function. This would provide a potential target for the assessment and intervention of AA toxicity.

Curcumin Attenuates the PERK-eIF2α Signaling to Relieve Acrylamide-Induced Neurotoxicity in SH‑SY5Y Neuroblastoma Cells

Curcumin is a natural polyphenolic compound with neuroprotective and antioxidant properties. Acrylamide (ACR) is a by-product of food processing that produces neurotoxicity in humans and animals. The pancreatic endoplasmic reticulum kinase (PERK)-eukaryotic initiation factor-2α (eIF2α) signaling is involved in the occurrence of neurotoxicities. This study is aimed to investigate the protective effect of curcumin on ACR-induced cytotoxicity and explore the role of PERK-eIF2α signaling in this process. ACR exposure at 2.5 mM for 24 h caused oxidative stress as revealed by the distinct increase in cellular reactive oxygen species (ROS) and malondialdehyde (MDA) level, and a significant decrease in glutathione (GSH) content. ACR induced phosphorylated tau aggregation, phosphorylated cAMP response elements binding protein (CREB) reduction, and Bax/Bcl-2 ratio up-regulation in SH-SY5Y cells. ACR also activated the PERK-eIF2α signaling in SH-SY5Y cells and triggered the activation of glycogen synthase kinase-3β (GSK-3β), up-regulated activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP). Curcumin pretreatment significantly attenuated ACR-induced neuronal toxicity as revealed by the ameliorated cell viability, mitigated intracellular ROS and MDA level, and elevated GSH content. Moreover, curcumin pretreatment inhibited PERK-dependent eIF2α phosphorylation, further suppressed GSK-3β and ATF4 function, and abolished abnormal tau phosphorylation, P-CREB reduction, and CHOP-induced apoptosis in SH-SY5Y cells. These results provided empirical evidence between curcumin and PERK-eIF2α signaling in ACR-induced neurotoxicity.

The Possible Protective Role of Dark Chocolate Against Acrylamide Neurotoxicity in Weaning Rats Cerebellum

Acrylamide (ACR) is selective neurotoxicity, could be found in foods processed by high temperature. This work aimed to evaluate the protective role of the dark chocolate (DC) against cerebellar neurotoxicity induced by subchronic ACR exposure in recently weaned rat pups and to propose it as protective supplement against dietary ACR hazards. Eighteen weaning pups were used in the current study and divided into three groups, six rats in each group; group 1 (control group), group 2 (ACR group), and group 3 (ACR + DC group). The pups were sacrificed after 21 days and the cerebellums were removed for light microscope using H&E stain, ultrastructural study, morphometric analysis of the neurons count, biochemical analysis of oxidant and antioxidant markers and real-time quantitative PCR to evaluate the nuclear receptor subfamily 4, group A, member 2 (Nr4a2) gene expression. Pups with ACR consumption showed signs of neuronal degeneration and reduced Nr4a2 expression. On the other hand, pups with ACR + DC consumption showed relative signs of neuronal restoration and enhanced Nr4a2 expression. In conclusion, DC can be used as effective supplement to decrease the dietary ACR cerebellar neuronal risks.

Unraveling the Serum Metabolomic Profile of Acrylamide-Induced Cardiovascular Toxicity

Acrylamide has been reported as an important dietary risk factor from carbohydrate-rich processing food. However, systemic biological effects on the serum metabolomics induced by acrylamide have poorly been understood. In the present study, we evaluated the metabolic profiles in a rat serum after exposure to acrylamide using ultrahigh-performance liquid chromatography combined with quadrupole-orbitrap high-resolution mass spectrometry. The serum biochemical parameters of the treated and control groups were also determined using an automatic biochemical analyzer. Compared with the control group, 10 metabolites were significantly upregulated, including citric acid, d-(-)-fructose, gluconic acid, l-ascorbic acid 2-sulfate, 2-hydroxycinnamic acid, valine, l-phenylalanine, prolylleucine, succinic acid, and cholic acid, while 5 metabolites were significantly downregulated, including 3-hydroxybutyric acid, 4-oxoproline, 2,6-xylidine, 4-phenyl-3-buten-2-one, and N-ethyl-N-methylcathinone in the serum of 4-week-old rats exposed to acrylamide in the high-dose group (all P < 0.05). Importantly, acrylamide exposure affected metabolites mainly involved in the citrate cycle, valine, leucine, and isoleucine biosyntheses, phenylalanine, tyrosine and tryptophan biosyntheses, and pyruvate metabolism. These results suggested that exposure to acrylamide in rats exhibited marked systemic metabolic changes and affected the cardiovascular system. This study will provide a theoretical basis for exploring the toxic mechanism and will contribute to the diagnosis and prevention of acrylamide-induced cardiovascular toxicity.

Morin protects against acrylamide-induced neurotoxicity in rats: an investigation into different signal pathways

The presented study investigates the effects of morin against toxicity induced by acrylamide (ACR) in the brains of Sprague Dawley rats. In this study, neurotoxicity was induced by orally administering 38.27 mg/kg/b.w ACR to rats through gastric gavage for 10 days. Morin was administered at the same time and at different doses (50 and 100 mg/kg/b.w) with ACR. Biochemical and Western blot analyses showed that ACR increased malondialdehyde (MDA), p38α mitogen-activated protein kinase (p38α MAPK), nuclear factor kappa-B (NF-κB), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), cyclooxygenase-2 (COX-2), p53, caspase-3, bcl-2 associated X protein (Bax), Beclin-1, light chain 3A (LC3A), and light chain 3B (LC3B) levels and decreased those of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH), b-cell lymphoma-2 (Bcl-2), mammalian target of rapamycin (mTOR), phosphoinositide 3-kinase (PI3K), and protein kinase B (Akt) in brain tissue and therefore induced neurotoxicity by causing oxidative stress, inflammation, apoptosis, and autophagy. On the other hand, it was determined that morin positively affected the levels of these markers by displaying antioxidant, anti-inflammatory, anti-apoptotic, and anti-autophagic properties and had a protective effect on ACR-induced neurotoxicity. As a result, morin is an effective substance against brain damage caused by ACR, yet further studies are needed to use it effectively.

Protective effects of selenium on acrylamide-induced neurotoxicity and hepatotoxicity in rats

Objective(s):

Acrylamide (ACR), has wide uses in different industries. ACR induced several toxicities including neurotoxicity and hepatotoxicity. The probable protective effects of selenium on ACR-induced neurotoxicity and hepatotoxicity in rats were evaluated.

Materials and Methods:

Male Wistar rats were studied for 11 days in 8 groups: 1. Control, 2. ACR (50 mg/kg, IP), 3-5. ACR+ selenium (0.2, 0.4, 0.6 mg/kg, IP), 6. ACR+ the most effective dose of selenium (0.6 mg/kg, IP) three days after ACR administration, 7. ACR+ vitamin E (200 mg/kg IP, every other day) 8. Selenium (0.6 mg/kg IP). Finally, behavioral tests were done. The levels of malondialdehyde (MDA), glutathione (GSH), Bcl-2, Bax and caspase 3 proteins in liver and cerebral cortex tissues were measured. Also, the amount of albumin, total protein, alanine transaminase (ALT) and aspartate transaminase (AST) enzymes were determined in serum.

Results:

ACR caused the severe motor impairment, increased MDA level and decreased GSH content, enhanced Bax/Bcl-2 ratio and caspase 3 proteins in brain and liver tissues. Besides, the level of AST was elevated while the total serum protein and albumin levels were decreased. Administration of selenium (0.6 mg/kg) (from the first day of the experiment and the third day) significantly recovered locomotor disorders, increased GSH content, and reduced MDA level. Also, selenium decreased Bax/Bcl-2 ratio and caspase 3 levels in brain and liver tissues.

Conclusion:

The oxidative stress and apoptosis pathways have important roles in neurotoxicity and hepatotoxicity of ACR. Selenium significantly reduced ACR-induced toxicity through inhibition of oxidative stress and apoptosis.

Acrylamide Induces Abnormal mtDNA Expression by Causing Mitochondrial ROS Accumulation, Biogenesis, and Dynamics Disorders

Acrylamide, a well-documented neurotoxicant, is commonly found as a byproduct of the Maillard reaction in carbohydrate-rich foods. Numerous studies have indicated that acrylamide-induced apoptosis accompanied by mitochondrial dysfunction contributes to its neurotoxicity. However, the mechanisms of how acrylamide causes mitochondrial impairment is not well understood. In this study, we observed destroyed redox balance, accumulated mitochondrial reactive oxygen species (ROS), damaged mitochondrial structures, and activated apoptosis in astrocytes following acrylamide treatment. Furthermore, acrylamide decreased the expression of mitochondrial biogenesis- and dynamics-related genes, including PGC-1α, TFAM, Mfn2, and Opa1, and altered the expression of mitochondrial DNA (mtDNA)-encoded mitochondrial respiratory chain complexes, along with the inhibited mitochondrial respiration. Pretreatment with a mitochondrial ROS scavenger mitoquinone dramatically restored the expressions of PGC-1α, TFAM, Mfn2, and Opa1; protected the mitochondrial structure; and decreased acrylamide-induced apoptosis. Further in vivo experiments confirmed that acrylamide decreased the expressions of PGC-1α, TFAM, Mfn2, and Opa1 in rat brain tissues. These results revealed that acrylamide triggered the mitochondrial ROS accumulation to interfere with mitochondrial biogenesis and dynamics, causing mtDNA damage and finally resulting in mitochondrial dysfunction and apoptosis.

Rosmarinic acid attenuates acrylamide induced apoptosis of BRL-3A cells by inhibiting oxidative stress and endoplasmic reticulum stress

Acrylamide (AA) is a common endogenous contaminant in food, with a complex toxicity mechanism. The study on liver damage to experimental animals caused by AA has aroused a great attention. Rosmarinic acid (RosA) as a natural antioxidant shows excellent protective effects against AA-induced hepatotoxicity, but the potential mechanism is still unclear. In the current study, the protective effect of RosA on BRL-3A cell damage induced by AA was explored. RosA increased the activity of SOD and GSH, reduced the content of ROS and MDA, and significantly reduced the oxidative stress (OS) damage of BRL-3A cells induced by AA. RosA pretreatment inhibited the MAPK signaling pathway activated by AA, and down-regulated the phosphorylation of JNK, ERK and p38. RosA pretreatment also reduced the production of calcium ions caused by AA. In addition, the key proteins p-IRE1α, XBP-1s, TRAF2 of the IRE1 pathway, and the expression of endoplasmic reticulum stress (ERS) characteristic proteins GRP78, p-ASK1, Caspase-12 and CHOP were also down-regulated by RosA. NAC blocked the activation of the MAPK signaling pathway and inhibited the ERS pathway. RosA reduced the rate of apoptosis and down-regulated the expression of Bax/Bcl-2 and Caspase-3, thereby inhibiting AA-induced apoptosis. In conclusion, RosA reduced the OS and ERS induced by AA in BRL-3A cells, thereby inhibiting cell apoptosis, and it could be used as a potential protective agent against AA toxicity.

Morin attenuates acrylamide-induced testicular toxicity in rats by regulating the NF-κB, Bax/Bcl-2 and PI3K/Akt/mTOR signaling pathways

AIM

Acrylamide (AC) is a carcinogenic substance which is formed during the heating of starchy foods at high temperatures and constitutes an important risk for human health. Therefore, reducing the detrimental effects of AC has become an important research topic. This study was performed to evaluate the protective effect of morin against the testicular toxicity induced by AC in male rats.

MATERIALS AND METHODS

Testicular damage was evaluated after the rats were treated orally with AC (38.27 mg/kg body weight) alone or with morin (50 and 100 mg/kg body weight) for 10 consecutive days.

KEY FINDINGS

Our results showed that treatment with morin could significantly decrease MDA level and considerably increase the activity of antioxidant enzymes (SOD, CAT, GPx) and GSH level in the testicular tissue of the AC-treated rats. Morin supplementation also suppressed the activation of inflammatory, apoptotic and autophagic pathways by increasing Bcl-2 and decreasing p38α MAPK, TNF-α, NF-κB, IL-1β, IL-6, COX-2, cytochrome c, Bax, caspase-3, LC3A, LC3B and beclin-1 protein levels. Morin also alleviated the side effects caused by AC by regulating the PI3K/Akt/mTOR signaling pathway.

SIGNIFICANCE

Collectively, our results have shown the possible protective mechanism of morin, a potential therapeutic agent for AC-induced testicular toxicity.

Tetrastigma hemsleyanum leaves extract against acrylamide-induced toxicity in HepG2 cells and Caenorhabditis elegans

Acrylamide (ACR), as a raw material of polyacrylamide that used in water purification, was verified to possess various toxicity. Tetrastigma hemsleyanum (TH) is a medicinal plant widely used to anti-inflammation and anti-tumor in Chinese folks. However, more researches focused on the biological activities in tubers and the leaves were ignored. Thus, the protective effect of Tetrastigma hemsleyanum leaves extract (THLE) against ACR-induced toxicity in HepG2 cells and Caenorhabditis elegans (C. elegans) was explored in this study. In vitro, we observed that THLE attenuated ACR-induced toxicity in HepG2 cell via regulating Akt/mTOR/FOXO1/MAPK signaling pathway. Further research proved that 5-caffeoylquinic acid (5-CA) plays a major role in THLE's amelioration effect of ACR toxicity. In vivo, it was found that THLE possesses the same protective effect in ACR-treated wild-type N2 C. elegans and daf-2 (-) (deficit in DAF-2) mutants. However, the anti-ACR toxicity effect of THLE in daf-16 (-) mutants (deficit in DAF-16 that homologous to FOXO family in human) was weakened. Our results indicated that THLE exhibited protective effects against ACR-induced toxicity both in HepG2 cells and C. elegans, while DAF-16/FOXO gene is involved in THLE' protective effect via regulating the expression levels of downstream antioxidant genes.

6'"-p-Coumaroylspinosin protects PC12 neuronal cells from acrylamide-induced oxidative stress and apoptosis

6'"-p-coumaroylspinosin (P-CS) is a flavonoid isolated from Ziziphi Spinosae Semen (ZSS), whereas, the antioxidative activity has not been reported. Oxidative stress is believed to be one of the main causes of neurodegenerative disorders. In this study, the antioxidative effect of P-CS on PC12 cells was determined. The cells were treated with acrylamide (AA) in the absence or presence of P-CS, and cell apoptosis was analyzed. Interestingly, P-CS pretreatment of the cells could significantly prevent AA-induced cell death, glutathione (GSH) contents decrease, and reactive oxygen species (ROS) overproduction. Further investigation of the molecular mechanism underlying the effect of P-CS on cell apoptosis revealed that P-CS was able to suppress the expression of Bax and Bim induced by AA and inhibit the JNKs pathway. Our findings support a role of P-CS in preventing neuronal cell apoptosis induced by AA, suggesting its therapeutic potential for the treatment of neurodegenerative disorders as a medicinal supplement. PRACTICAL APPLICATIONS: Oxidative stress is believed to cause damage in subcellular organelles, nucleic acids, and alteration in protein aggregation as well as disruption of the signaling cascades associated with aging and apoptosis. A small molecule, non-poisonous natural antioxidant is needed to protect the brain from oxidative stress. Compared with western medicine, natural products carry less risk of adverse effects and are not too expensive, especially for the third-world countries. Furthermore, ZSS could be used to produce or prepare antioxidants, such as P-CS, which has been reported significant anti-oxidative activity in this study.

Protective effects of morin against acrylamide-induced hepatotoxicity and nephrotoxicity: A multi-biomarker approach

Acrylamide (ACR) is a heat-induced carcinogen substance that is found in some foods due to cooking or other thermal processes. The aim of present study was to assess the probable protective effects of morin against ACR-induced hepatorenal toxicity in rats. The rats were treated with ACR (38.27 mg/kg b.w., p.o.) alone or with morin (50 and 100 mg/kg b.w., p.o.) for 10 consecutive days. Morin treatment attenuated the ACR-induced liver and kidney tissue injury by diminishing the serum AST, ALP, ALT, urea and creatinine levels. Morin increased activities of SOD, CAT and GPx and levels of GSH, and suppressed lipid peroxidation in ACR induced tissues. Histopathological changes and immunohistochemical expressions of p53, EGFR, nephrin and AQP2 in the ACR-induced liver and kidney tissues were decreased after administration of morin. In addition, morin reversed the changes in levels of apoptotic, autophagic and inflammatory parameters such as caspase-3, bax, bcl-2, cytochrome c, beclin-1, LC3A, LC3B, p38α MAPK, NF-κB, IL-1β, IL-6, TNF-α and COX-2 in the ACR-induced toxicity. Morin also affected the protein levels by regulating the PI3K/Akt/mTOR signaling pathway and thus alleviated ACR-induced apoptosis and autophagy. Overall, these findings may shed some lights on new approaches for the treatment of ACR-induced hepatotoxicity and nephrotoxicity.

Acrylamide Induced Toxicity and the Propensity of Phytochemicals in Amelioration: A Review

Acrylamide is widely found in baked and fried foods, produced in large amount in industries and is a prime component in toxicity. This review highlights various toxicities that are induced due to acrylamide, its proposed mode of action including oxidative stress cascades and ameliorative mechanisms using phytochemicals. Acrylamide formation, the mechanism of toxicity and the studies on the role of oxidative stress and mitochondrial dysfunctions are elaborated in this paper. The various types of toxicities caused by Acrylamide and the modulation studies using phytochemicals that are carried out on various type of toxicity like neurotoxicity, hepatotoxicity, cardiotoxicity, immune system, and skeletal system, as well as embryos have been explored. Lacunae of studies include the need to explore methods for reducing the formation of acrylamide in food while cooking and also better modulators for alleviating the toxicity and associated dysfunctions along with identifying its molecular mechanisms.

Neuroprotective effects of notoginsenoside R1 by upregulating Trx-1 on acrylamide-induced neurotoxicity in PC12

Acrylamide (ACR) is a water-soluble chemical that is commonly used in chemical and cosmetic manufacture. Many studies have been carried out to investigate the neurotoxicity mechanisms of ACR, resulting in oxidative stress and nerve damages. One of the commonly used traditional Chinese medicines is notoginsenoside R1 (NR1). However, its mitochondrial-mediated apoptotic effect caused in ACR-induced neurotoxicity has not been reported. Our results have shown that NR1 resisted the neurotoxicity induced by ACR by upregulating the levels of thioredoxin-1 (Trx-1) in Rat adrenal chromaffin cell tumor (PC12) cells. NR1 inhibited the increase in levels of Bax, caspase-9, and caspase-3, which was instigated by ACR. Moreover, NR1 inhibited the decrease in levels of B-cell lymphoma 2 and Trx-1 induced by ACR. The downregulation of Trx-1 aggravated the mitochondrial-mediated apoptosis and increased the expression of the above molecules, which was induced by ACR. In contrast, overexpression of Trx-1 attenuated the mitochondrial-mediated apoptosis and inhibited the expression of the mentioned molecules induced by ACR. Our results suggested that NR1 protected ACR-induced mitochondrial apoptosis by upregulating Trx-1.

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.

A study of digital image analysis on the acrylamide derivative monomers induced apoptosis in rat cerebrum

Nowadays, apoptosis is mostly evaluated visually in histological studies. By using the quantitative digital image analysis, this study aimed to investigate the effect of acrylamide-based monomers (acrylamide [AAm], methacrylamide [MAAm], N-isopropylacrylamide [NIPAm]) on the cerebrum tissues in rats, which are the most common water-soluble monomers in the production of polymeric hydrogels used as biomaterials. The Wistar albino rats weighing ~220-240 g were divided into control and three test groups. The control group received 1 mL of saline, and the test groups received 1 mL of aqueous 50 mg/kg/day intramuscular injection of AAm, MAAm, and NIPAm, respectively. At the end of the experiments, brain tissues of all rats euthanized by intramuscular injection of sodium pentobarbital were removed. Terminal deoxynucleotide transferase dUTP nick and labeling (TUNEL) method was applied to brain tissue sections. The monomers have been shown to cause apoptosis due to oxidative stress in cerebrum tissue. Based on apoptosis by tunneling method, quantitative digital image analysis of cell fragments was performed with Olympus cellSens Dimension 1.15 software, and the number, total count area, selected area, average area, and ROI% values of the fragments were found. In addition, the total area and ROI% values of the fragments increased linearly with increasing the molar mass of monomers from the digital image analysis data. Quantitative digital image analysis can facilitate the monitoring of apoptosis caused by the oxidative stress of monomers used in the production of the biomaterials.

Effect of acrylamide on BEAS-2B normal human lung cells: Cytotoxic, oxidative, apoptotic and morphometric analysis

Due to the broad toxic relevance of acrylamide, many measures have been taken since the 1900s. These measures increased day by day when acrylamide was discovered in foods in 2002, and its toxic spectrum was found to be wider than expected. Therefore, in some countries, the products with higher acrylamide content were restricted. On the other hand, the effects of acrylamide on the respiratory system cells have yet to be well understood. In this study, we aimed at investigating the effect of acrylamide on lung epithelial BEAS-2B cells. Initially, the cytotoxic effect of acrylamide on BEAS-2B was determined by MTT assay. Then, cellular oxidative stress was measured. Flow cytometry analysis was conducted for Annexin-V and caspase 3/7. Furthermore, Bax, Bcl-2 and Nrf-2 proteins were evaluated by immunocytochemistry. Finally, acrylamide-induced cellular morphological changes were observed under confocal and TEM microscopes. According to MTT results, the IC50 concentration of acrylamide was 2.00 mM. After acrylamide treatment, oxidative stress increased dose-dependently. Annexin V-labelled apoptotic cells and caspase 3/7 activity were higher than untreated cells in acrylamide-treated cells. Immunocytochemical examination revealed a marked decrease in Bcl-2, an increase in Bax and Nrf-2 protein staining upon acrylamide treatment. Furthermore, in confocal and TEM microscopy, apoptotic hallmarks were pronounced. In the present study, acrylamide was suggested to display anti-proliferative activity, decrease viability, induce apoptosis and oxidative stress and cause morphological changes in BEAS-2B cells.

Exposure to acrylamide disrupts cardiomyocyte interactions during ventricular morphogenesis in zebrafish embryos

Acrylamide (AA), a ubiquitous chemical that is present in surrounding environment and baked or fried carbohydrate-rich food, has recently been linked to cardiac developmental toxicity. However, the toxicological role of AA exposure in the cardiac development remains largely unknown. Here we showed the cardiotoxicity of AA and its role in cardiomyocyte interactions in zebrafish embryos during ventricular morphogenesis. Using the embryo model of transgenic zebrafish Tg(Tp1:d2GFP;myl7:mCherry), we found AA interfered the dynamics of Notch signaling in the endocardium during early cardiogenesis. Prolonged exposure to AA thickened the chamber wall and prevented the trabeculae from extending into the lumen of ventricular chamber. As a result, AA reduced the ventricular shortening fraction and spatial dimension via excessively activating the Notch signal in myocardium during cardiac maturation. Moreover, exposure to AA inhibited the re-distribution of N‑cadherin and failed to coordinate cardiomyocyte interactions between the myocardium layers due to the lack of delaminated cardiomyocytes. Therefore, AA-treated embryos exhibited subcellular pathological states including disarrayed myofibrils and abnormal morphology of mitochondria despite normal proliferation of cardiomyocytes. In addition, we found overexpression of some cardiac-specific transcription factors, such as hand2 and nkx2.5, in hearts of AA-treated embryos compared with those in control group. Our study provided the evidence that the period of ventricular chamber morphogenesis might be a vulnerable window in zebrafish, and revealed new insights into how AA might exert cardiac developmental toxicity.

Neuroprotective Effects of Thymoquinone in Acrylamide-Induced Peripheral Nervous System Toxicity Through MAPKinase and Apoptosis Pathways in Rat

Acrylamide (ACR) is extensively used in industrial areas and has been demonstrated to induce neurotoxicity via oxidative stress and apoptosis. In this study, we assessed the probable protective effects of thymoquinone (TQ), an active constituent of Nigella sativa, against ACR-induced neurotoxicity. ACR (50 mg/kg, i.p., for 11 days) and TQ (2.5, 5 and 10 mg/kg, i.p., for 11 days) were administered to rats. On 12th day, gait score was examined and rats were sacrificed. Malondialdehyde (MDA) and reduced glutathione (GSH) contents were determined in sciatic nerve. Furthermore, western blotting was conducted. The exposure of rats to ACR caused severe gait disabilities. The MDA and GSH contents were increased and decreased, respectively. ACR decreased P-ERK/ERK ratio and myelin basic protein (MBP) content, but significantly increased P-JNK/JNK, P-P38/P38, Bax/Bcl-2 ratios and caspase 3 and 9 levels. Concurrently administration of TQ (5 and 10 mg/kg) with ACR, prevented gait abnormalities and meaningfully reduced MDA and elevated the GSH contents. Furthermore, TQ (5 mg/kg) elevated the P-ERK/ERK ratio and MBP content while reduced the P-JNK/JNK, P-P38/P38 ratios and apoptotic markers. MAP kinase and apoptosis signaling pathways were involved in ACR-induced neurotoxicity in rat sciatic nerve and TQ significantly reduced ACR neurotoxicity. TQ afforded neuroprotection, in part, due to its anti-oxidative stress and anti-apoptotic mechanisms.

Protective effects of a Ganoderma atrum polysaccharide against acrylamide induced oxidative damage via a mitochondria mediated intrinsic apoptotic pathway in IEC-6 cells

The preventive role of a purified Ganoderma atrum polysaccharide PSG-1-F₂ as a new dietary antioxidant against the intestinal toxicity of acrylamide (ACR) was investigated in vitro. Our results showed that ACR could induce oxidative stress in IEC-6 cells by the overproduction of reactive oxygen species (ROS) and malondialdehyde (MDA), and as well as the reduction in the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). In addition, the induction of a mitochondria-mediated intrinsic apoptotic pathway by ACR was evidenced by the events of loss of mitochondrial membrane potential, bax/bcl-2 dysregulation, cytochrome c release, and activation of caspase-3. Interestingly, PSG-1-F₂ was able to suppress ACR toxicity by improving the redox status of IEC-6 cells and by attenuating mitochondria-mediated apoptosis. Its protective effect was even superior to the clinically used antioxidant N-acetylcysteine (NAC). This study uniquely introduces PSG-1-F₂ as a potential inhibitor of ACR-induced stress and toxicities.

Acrylamide exerts its cytotoxicity in NIH/3T3 fibroblast cells by apoptosis

OBJECTIVE

Acrylamide is a chemical utilized in various industries, and many studies have demonstrated its toxicity. The NIH/3T3 mouse embryonic cell line is the standard cell line of fibroblasts, which have a pivotal role with their versatile functions in the body. However, only two studies have attempted to investigate the effect of acrylamide on these crucial cells. To fill this knowledge gap, we aimed to determine the effects of acrylamide on NIH/3T3 cells.

METHOD

First, we performed the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay and calculated the IC₅₀ dose of acrylamide. Then, we treated cells with the IC₅₀ dose of acrylamide for 24 h and determined whether the dominant death mode of NIH/3T3 cells was apoptosis or necrosis by annexin V and caspase 3/7 assays. Finally, we performed confocal microscopy and transmission electron microscope (TEM) analysis for observing the morphological alterations.

RESULTS

MTT assay results showed that acrylamide treatment reduced the viability of NIH/3T3 cells dose-dependently and that the IC₅₀ of acrylamide was 6.73 mM. Based on annexin V and caspase 3/7 assays, the dominant death mode of NIH/3T3 cells was determined to be apoptosis. Also, caspase 3/7 activities of the acrylamide-treated NIH/3T3 cells were three times greater than those of the untreated NIH/3T3 cells. Furthermore, we observed membrane blebbing, nuclear chromatin clumping, and cytoplasmic vacuolization in TEM analysis and apparent apoptotic bodies, nuclear fragmentations, and condensations in confocal microscopy.

CONCLUSIONS

In conclusion, our results suggested that the IC₅₀ of acrylamide against NIH/3T3 cells for 24 h was 6.73 mM and that acrylamide exerted its cytotoxic and anti-proliferative effects on these cells mainly via apoptosis.

Protective effects of lipoic acid against acrylamide-induced neurotoxicity: involvement of mitochondrial energy metabolism and autophagy

Acrylamide (ACR) is a chronic neurotoxin that is generated in high-starch foods during heat processing. Alpha-lipoic acid (LA) is an antioxidant that occurs in most plants and animals. The objective of this study was to reveal the mechanism of ACR-triggered neurotoxicity and identify the protective role of LA in SH-SY5Y cells. In this study, LA restored ACR-stimulated depletion of glutathione content and mitochondrial membrane potential, moderated the activation of inflammatory pathways, and recovered the Keap1/Nrf2 pathway. Moreover, LA upregulated the activities of oxidative phosphorylation complexes and diminished ACR-induced variation in AMPK/GSK3β, Ca²⁺ disturbance, and ATP depletion. The Sirt1/PGC-1α pathway was inhibited by ACR. Notably, autophagy was activated in the mitochondria-mediated apoptosis induced by ACR, which was also blocked by LA. Overall, our study demonstrated the pivotal roles of the mitochondrial energy metabolism and autophagy in the protective effects of LA and cytotoxicity of ACR in SH-SY5Y cells.

Learning, memory deficits, and impaired neuronal maturation attributed to acrylamide

Acrylamide (ACR) is a neurotoxin known to produce neurotoxicity characterized by ataxia, skeletal muscle weakness, cognitive impairment, and numbness of the extremities. Previously, investigators reported that high-dose (50 mg/kg) ACR impaired hippocampal neurogenesis and increased neural progenitor cell death; however, the influence of subchronic environmentally relevant low dose-(2, 20, or 200 μg/kg) ACRs have not been examined in adult neurogenesis or cognitive function in mice. Accordingly, the aim of the present study was to investigate whether low-dose ACR adversely affected mouse hippocampal neurogenesis and neurocognitive functions. Male C57BL/6 mice were orally administered vehicle or ACR at 2, 20, or 200 μg/kg/day for 4 weeks. ACR did not significantly alter the number of newly generated cells or produce neuroinflammation or neuronal loss in hippocampi. However, behavioral studies revealed that 200 μg/kg ACR produced learning and memory impairment. Furthermore, incubation of ACR with primary cultured neurons during the developmental stage was found to delay neuronal maturation without affecting cell viability indicating the presence of developmental neurotoxicity. These findings indicate that although exposure to in vivo low-dose ACR daily for 4 weeks exerted no apparent marked effect on hippocampal neurogenesis, in vitro observations in primary cultured neurons noted adverse effects on learning and memory impairment suggestive of neurotoxic actions.

Taurine attenuates acrylamide-induced apoptosis via a PI3K/AKT-dependent manner

As a potent neurotoxic agent, acrylamide (ACR) is formed in food processing at higher temperature. Taurine (TAU), a nonessential amino acid, is used to cure neurodegenerative disorders, followed by activation of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway. In this article, we certified that antiapoptotic efficacy of TAU in vivo and vitro. ACR-treated rats received TAU by drinking water 2 weeks after ACR intoxication. The results showed that in treated rats, TAU alleviated ACR-induced neuronal apoptosis, which was associated with the activation of PI3K/AKT signaling pathway. TAU attenuated apoptosis caused by ACR through observing terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells, measure of protein expression of Bcl-2, Bax, and caspase 3 activity. TAU-induced antiapoptotic effect is PI3K/AKT-dependent, which was proved in ACR-intoxicated ventral spinal cord 4.1 cells in the presence of AKT inhibitor, MK-2206. Therefore, our results demonstrated that TAU-attenuated ACR-induced apoptosis in vivo through a PI3K/AKT-dependent manner provided new sights in the molecular mechanism of TAU protection against ACR-induced neurotoxicity.

Mesenchymal Stem Cells Protect Nucleus Pulposus Cells from Compression-Induced Apoptosis by Inhibiting the Mitochondrial Pathway

Objective

Excessive apoptosis of nucleus pulposus cells (NPCs) induced by various stresses, including compression, contributes to the development of intervertebral disc degeneration (IVDD). Mesenchymal stem cells (MSCs) can benefit the regeneration of NPCs and delay IVDD, but the underlying molecular mechanism is poorly understood. This study aimed to evaluate the antiapoptosis effects of bone marrow-derived MSC (BMSC) on rat NPCs exposed to compression and investigate whether the mitochondrial pathway was involved.

Methods

BMSCs and NPCs were cocultured in the compression apparatus at 1.0 MPa for 36 h. Cell viability, apoptosis, mitochondrial function, and the expression of apoptosis-related proteins were evaluated.

Results

The results showed that coculturing with BMSCs increased the cell viability and reduced apoptosis of NPCs exposed to compression. Meanwhile, BMSCs could relieve the compression-induced mitochondrial damage of NPCs by decreasing reactive oxygen species level and maintaining mitochondrial membrane potential as well as mitochondrial integrity. Furthermore, coculturing with BMSCs suppressed the activated caspase-3 and activated caspase-9, decreased the expressions of cytosolic cytochrome c and Bax, and increased the expression of Bcl-2.

Conclusions

Our results suggest that BMSCs can protect against compression-induced apoptosis of NPCs by inhibiting the mitochondrial pathway and thus enhance our understanding on the MSC-based therapy for IVDD.