Acrylamide induces immunotoxicity through reactive oxygen species production and caspase-dependent apoptosis in mice splenocytes via the mitochondria-dependent signaling pathways

Impacts of Acrylamide on testis and spermatozoa

Acrylamide (ACR) is an industrial chemical used to produce polyacrylamide, a synthetic polymer with a wide range of applications. Depending on the dosage, its presence in occupational and environmental sources poses potential health risks to humans and animals. ACR can be formed in starchy foods cooked at high temperatures. Its effects on human sperm are not well understood. Animal studies indicate that ACR induces toxicity in the male reproductive system through oxidative stress mechanisms. Exposure to ACR alters the normal structure of testicular tubules, leading to congestion, interstitial edema, degeneration of spermatogenic cells, formation of abnormal spermatid giant cells, and necrosis and apoptosis. It also disrupts the balance of important biomarkers such as malondialdehyde, nitric oxide, superoxide dismutase, catalase, and glutathione. ACR has a negative impact on mitochondrial function, antioxidant enzymes, ATP production, and sperm membrane integrity, resulting in decreased sperm quality. Furthermore, it interferes with the expression of steroidogenic genes associated with testosterone biosynthesis. This review explores the detrimental effects of ACR on sperm and testicular function and discusses the potential role of antioxidants in mitigating the adverse effects of ACR on male reproduction.

Acrylamide in food products and the role of electrochemical biosensors in its detection: a comprehensive review

In this review, the mechanisms of acrylamide formation in food, along with aspects related to its toxicity and associated consumption risks, are investigated, highlighting the potential impact on human health. European regulations regarding acrylamide content in food products are also addressed, emphasizing the importance of monitoring and detecting this substance in nutrition, by public health protection measures. The primary objective of the research is to explore and analyze innovative methods for detecting acrylamide in food, with a particular focus on electrochemical biosensors. This research direction is motivated by the need to develop rapid, sensitive, and efficient monitoring techniques for this toxic compound in food products, considering the associated consumption risks. The research has revealed several significant results. Studies have shown that electrochemical biosensors based on hemoglobin exhibited increased sensitivity and low detection limits, capable of detecting very low concentrations of acrylamide in processed foods. Additionally, it has been found that the use of functionalized nanomaterials, such as carbon nanotubes and gold nanoparticles, has led to the improvement of electrochemical biosensor performance in acrylamide detection. The integration of these technological innovations and functionalization strategies has enhanced the sensitivity, specificity, and stability of biosensors in measuring acrylamides. Thus, the results of this research offer promising perspectives for the development of precise and efficient methods for monitoring acrylamides in food, contributing to the improvement of food quality control and the protection of consumer health.

Protective role of vitamin E against acrylamide-induced testicular toxicity from pregnancy to adulthood: insights into oxidative stress and aromatase regulation

Acrylamide (ACR) is a toxic chemical frequently encountered in daily life, posing health risks. This study aimed to elucidate the molecular-level mechanism of ACR's toxic effects on testicles and investigate whether Vitamin E can mitigate these effects. A total of 40 adult pregnant rats were utilized, divided into four groups: Control, ACR, Vitamin E, and ACR + Vitamin E. ACR and Vitamin E were administered to the mother rats during pregnancy and lactation, and to the male offspring until the 8th week post-birth. Serum hormone levels, oxidant-antioxidant parameters, histopathological examination of testicular tissue, and mRNA and protein levels of the testicular and liver aromatase gene were analyzed. Spermiogram analysis was conducted on the collected sperm samples from the male offspring. The results revealed that ACR exposure adversely affected hormone levels, oxidant-antioxidant parameters, histological findings, as well as aromatase gene and protein expressions. However, Vitamin E administration effectively prevented the toxic effects of ACR. These findings demonstrate that ACR application significantly impairs the reproductive performance of male offspring rats by increasing liver aromatase activity.

Environmental pollutants induce NLRP3 inflammasome activation and pyroptosis: Roles and mechanisms in various diseases

Environmental pollution is changing with economic development. Most environmental pollutants are characterized by stable chemical properties, strong migration, potential toxicity, and multiple exposure routes. Harmful substances are discharged excessively, and large quantities of unknown new compounds are emerging, being transmitted and amplifying in the food chain. The increasingly severe problems of environmental pollution have forced people to re-examine the relationship between environmental pollution and health. Pyroptosis and activation of the NLRP3 inflammasome are critical in maintaining the immune balance and regulating the inflammatory process. Numerous diseases caused by environmental pollutants are closely related to NLRP3 inflammasome activation and pyroptosis. We intend to systematically explain the steps and important events that are common in life but easily overlooked by which environmental pollutants activate the NLRP3 inflammasome and pyroptosis pathways. This comprehensive review also discusses the interaction network between environmental pollutants, the NLRP3 inflammasome, pyroptosis, and diseases. Thus, research progress on the impact of decreasing oxidative stress levels to inhibit the NLRP3 inflammasome and pyroptosis, thereby repairing homeostasis and reshaping health, is systematically examined. This review aims to deepen the understanding of the impact of environmental pollutants on life and health and provide a theoretical basis and potential programs for the development of corresponding treatment strategies.

Reconstructing hepatic metabolic profile and glutathione-mediated metabolic fate of acrylamide

The toxicity of acrylamide (AA) has continuously attracted wide concerns as its extensive presence from both environmental and dietary sources. However, its hepatic metabolic transformation and metabolic fate still remain unclear. This study aims to unravel the metabolic profile and glutathione (GSH) mediated metabolic fate of AA in liver of rats under the dose-dependent exposure. We found that exposure to AA dose-dependently alters the binding of AA and GSH and the generation of mercapturic acid adducts, while liver as a target tissue bears the metabolic transformation of AA via regulating GSH synthesis and consumption pathways, in which glutamine synthase (GSS), cytochrome P450 2E1 (CYP2E1), and glutathione S-transferase P1 (GSTP1) play a key role. In response to high- and low-dose exposures to AA, there were significant differences in liver of rats, including the changes in GSH and cysteine (CYS) activities and the conversion ratio of AA to glycidamide (GA), and liver can affect the transformation of AA by regulating the GSH-mediated metabolic pathway. Low-dose exposure to AA activates GSH synthesis pathway in liver and upregulates GSS activity and CYS content with no change in γ-glutamyl transpeptidase 1 (GGT1) activity. High-dose exposure to AA activates the detoxification pathway of GSH and increases GSH consumption by upregulating GSTP1 activity. In addition, molecular docking results showed that most of the metabolic molecules transformed by AA and GA other than themselves can closely bind to GSTP1, GSS, GGT1, N-acetyltransferase 8, and dimethyl sulfide dehydrogenase 1. The binding of AA-GSH and GA-GSH to GSTP1 and CYP2E1 enzymes determine the tendentiousness between toxicity and detoxification of AA, which exerts a prospective avenue for targeting protective role of hepatic enzymes against in vivo toxicity of AA.

The Protective Effects of Trametes Versicolor on Arsenic-Induced Male Reproductive Toxicity through Regulation of Oxidative Stress: A Biochemical and Histopathological Survey

Exposure to arsenic is linked to a wide range of diseases, in particular male reproductive toxicities. Trametes versicolor is a traditional medicinal fungus with a remarkable potential for antioxidant activity. The purpose of this study was to examine the ameliorating effects of water and methanol extracts of T. versicolor on arsenic-induced male reproductive toxicities via the abrogation of oxidative stress. The mice were divided as follows: control: normal saline, As: arsenic (15 mg/kg), WE: water extract (400 mg/kg), ME: methanol extract (400 mg/kg), As + WE: arsenic (15 mg/kg) + water extract (100, 200, 400 mg/kg), As + ME: arsenic (15 mg/kg) + methanol extract (100, 200, 400 mg/kg), and positive control: arsenic (15 mg/kg) + vitamin C (500 mg/kg). Animals were treated via the intraperitoneal route. About 24 hr later, the mice were euthanized, and oxidative stress parameters (reactive oxygen species [ROS], lipid peroxidation, glutathione concentration, protein carbonylation, glutathione peroxidase, and superoxide dismutase activity), histopathological changes and sperm parameters (count, motility, and morphology) were examined in the testicular tissue. Arsenic caused significant pathological changes in the testicular tissue and sperm morphology and significantly reduced sperm count and motility. Moreover, arsenic mediated oxidative stress via significant increases in ROS generation, lipid peroxidation, and protein carbonyl content, as well as significant depletion in glutathione concentration and superoxide dismutase and glutathione peroxidase activities. Although, coadministration of water and methanol extracts of T. versicolor at 200 and 400 mg/kg counteracted arsenic-induced oxidative and histopathological damages and improved sperm parameters. Our study indicated that T. versicolor ameliorated arsenic-induced testis toxicity and sperm dysfunction via attenuation of oxidative damage.

Acrylamide in food: Occurrence, metabolism, molecular toxicity mechanism and detoxification by phytochemicals

Acrylamide (ACR) is a common pollutant formed during food thermal processing such as frying, baking and roasting. ACR and its metabolites can cause various negative effects on organisms. To date, there have been some reviews summarizing the formation, absorption, detection and prevention of ACR, but there is no systematic summary on the mechanism of ACR-induced toxicity. In the past five years, the molecular mechanism for ACR-induced toxicity has been further explored and the detoxification of ACR by phytochemicals has been partly achieved. This review summarizes the ACR level in foods and its metabolic pathways, as well as highlights the mechanisms underlying ACR-induced toxicity and ACR detoxification by phytochemicals. It appears that oxidative stress, inflammation, apoptosis, autophagy, biochemical metabolism and gut microbiota disturbance are involved in various ACR-induced toxicities. In addition, the effects and possible action mechanisms of phytochemicals, including polyphenols, quinones, alkaloids, terpenoids, as well as vitamins and their analogs on ACR-induced toxicities are also discussed. This review provides potential therapeutic targets and strategies for addressing various ACR-induced toxicities in the future.

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.

BDE-47 Induces Immunotoxicity in RAW264.7 Macrophages through the Reactive Oxygen Species-Mediated Mitochondrial Apoptotic Pathway

Polybrominated diphenyl ethers (PBDEs) are classic and emerging pollutants that are potentially harmful to the human immune system. Research on their immunotoxicity and mechanisms suggests that they play an important role in the resulting pernicious effects of PBDEs. 2,2',4,4'-Tetrabrominated biphenyl ether (BDE-47) is the most biotoxic PBDE congener, and, in this study, we evaluated its toxicity toward RAW264.7 cells of mouse macrophages. The results show that exposure to BDE-47 led to a significant decrease in cell viability and a prominent increase in apoptosis. A decrease in mitochondrial membrane potential (MMP) and an increase in cytochrome C release and caspase cascade activation thus demonstrate that cell apoptosis induced by BDE-47 occurs via the mitochondrial pathway. In addition, BDE-47 inhibits phagocytosis in RAW264.7 cells, changes the related immune factor index, and causes immune function damage. Furthermore, we discovered a significant increase in the level of cellular reactive oxygen species (ROS), and the regulation of genes linked to oxidative stress was also demonstrated using transcriptome sequencing. The degree of apoptosis and immune function impairment caused by BDE-47 could be reversed after treatment with the antioxidant NAC and, conversely, exacerbated by treatment with the ROS-inducer BSO. These findings indicate that oxidative damage caused by BDE-47 is a critical event that leads to mitochondrial apoptosis in RAW264.7 macrophages, ultimately resulting in the suppression of immune function.

Quercetin ameliorates acute acrylamide induced spleen injury

Acrylamide is used for industrial and laboratory purposes; it also is produced during cooking of carbohydrate-rich food at high temperature. We investigated the therapeutic potential of quercetin for treatment of acute acrylamide induced injury to the spleen. We used female albino rats treated with acrylamide for 10 days followed by oral administration of quercetin in three doses for 5 days. We observed significantly reduced total body weight, spleen weight, red blood cells, total proteins, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phophate dehydrogenase, reduced glutathione, concentration of serum IgG and IgM after acrylamide induced toxicity compared to controls. We also found that white blood cells, triglycerides, cholesterol and lipid oxidation were increased significantly after acrylamide induced toxicity in rats compared to controls. Histoarchitecture of spleen was affected adversely by acrylamide toxicity. Administration of quercetin ameliorated adverse effects of acrylamide in a dose-dependent manner. Quercetin appears to ameliorate acrylamide induced injury to the spleen by increasing endogenous antioxidants and improving histoarchitecture and immune function.

Catechins protect against acrylamide- and glycidamide-induced cellular toxicity via rescuing cellular apoptosis and DNA damage

Acrylamide (AA) occurs in both various environmental and dietary sources and has raised widespread concern as a probable carcinogen. Glycidamide (GA) is the main genotoxic metabolite through P450 2E1 (CYP2E1). In the present study, we investigate the protective effect of (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin (EC) against AA- and GA-induced hepatotoxicity in HepG2 cells. The results demonstrated that EC and EGCG inhibited AA- and GA-induced cytotoxicity and mitochondria-mediated cellular apoptosis. Moreover, exposure to AA (100 μg/mL) and GA (50 μg/mL) caused cell cycle arrest and DNA damage, while EC and EGCG ranging from 12.5 to 50 μg/mL rescued cell cycle arrest and inhibited DNA damage. Furthermore, EC and EGCG down-regulated pro-apoptotic protein Bax and Caspase 3 after 24 h treatment in HepG2 cells exposed to AA (100 μg/mL) or GA (50 μg/mL). Also, the intervention with EC or EGCG up-regulated DNA repair related protein PARP and down-regulated expression of cleaved-PARP. Besides, EC exerted better protective effect than EGCG against AA- and GA-induced cytotoxicity in HepG2 cells. Altogether, EC and EGCG were effective in protecting AA- and GA-induced hepatotoxicity via rescuing cellular apoptosis and DNA damage, as well as promoting cell cycle progression in HepG2 cells.

Salvia spinosa L. Protects against Diabetes-Induced Nephropathy by Attenuation of Mitochondrial Oxidative Damage in Mice

Mitochondrial oxidative damage is a crucial factor in the pathogenesis of diabetic nephropathy (DN), which is among the most prevalent problems of diabetes, and there hasn't been an effective treatment for DN yet. This study planned to investigate the effects of Salvia spinosa L. on mitochondrial function along with its protection against streptozotocin-induced nephropathy in diabetic mice. After the injection of streptozotocin (STZ) and verification of the establishment of diabetes, mice (n = 30) were randomly divided into the following groups: control group, diabetic-control, S. spinosa-treated diabetic (50, 100, and 200 mg/kg), and metformin-treated diabetic group (500 mg/kg). After four weeks of treatment, the mice were weighed. Blood and kidney tissues were examined for biochemical and histological evaluation. Hematoxylin and eosin staining was used for evaluating renal pathologic damage. Oxidative damage in the kidney was assessed by the evaluation of lipid peroxidation and glutathione oxidation. Furthermore, differential centrifugation was used to obtain the isolated mitochondria, and mitochondrial toxicity endpoints (mitochondrial function and mitochondrial oxidative markers) were determined in them. S. spinosa remarkably reduced the blood urea and creatinine concentrations, and also normalized kidney weight/body weight coefficient in the diabetic mice. S. spinosa ameliorated the incidence of glomerular and tubular pathological changes in histological analyses. Moreover, the oxidative and mitochondrial damages were notably attenuated in renal tissues of S. spinosa-treated mice. These results indicate that the methanolic extract of S. spinosa modulates the nephropathy in the diabetic mice by the amelioration of oxidatively induced mitochondrial damage and provides a reliable scientific base, suggesting S. spinosa as a promising alternative remedy against DN.

Acrylamide-induced Changes of Granulopoiesis in Porcine Bone Marrow

Introduction

Due to the widely documented and diverse toxic effects of acrylamide, the authors decided to evaluate the impact of high and low doses of this compound on the process of granulopoiesis in porcine bone marrow.

Material and Methods

The experiment was conducted on 15 Danish Landrace pigs at the age of 8 weeks. The animals were randomly assigned into three equal groups (n = 5). Control animals received empty gelatine capsules as placebo. Animals in the first experimental group (the LD group) received a low dose of acrylamide of 0.5 μg/kg b.w./day, and animals in the second experimental group (the HD group) received a tenfold higher dose of acrylamide of 5 μg/kg b.w./day. Placebo and acrylamide capsules were administered with feed every morning for 28 days. Bone marrow was collected into tubes without an anticoagulant twice - before the first capsule administration (day 0) and on the 28^th day of the study. After drying and staining, bone marrow smears were subjected to detailed cytological evaluation under a light microscope.

Results

Changes in cell morphology, i.e. degenerative changes in the cellular nuclei, were observed in both experimental groups. Both low and high doses of acrylamide decreased the number of segmented eosinophils, neutrophilic and segmented metamyelocytes, neutrophils, as well as basophils and basophilic metamyelocytes.

Conclusion

Acrylamide at doses of 0.5 μg/kg b.w./day and 5 μg/kg b.w./day clearly influences porcine granulopoiesis.

Comprehensive analysis of metabolic changes in rats exposed to acrylamide

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

Acrylamide induces intrinsic apoptosis and inhibits protective autophagy via the ROS mediated mitochondrial dysfunction pathway in U87-MG cells

Acrylamide (ACR) is a potential neurotoxin commonly found in the environment, as well as in food repeatedly exposed heat processing, but the mechanism underpinning ACR-induced neurotoxicity remains unclear. This study investigated the potential association and underlying signal transduction of oxidative stress, apoptosis, and autophagy associated with ACR-triggered neurotoxicity. Therefore, U87-MG cells were treated with varying ACR concentrations, while the cell activity reduction depended on the specific dosage and time parameters. Biochemical analyses showed that ACR significantly increased the reactive oxygen species (ROS), malondialdehyde (MDA), and Ca²⁺ levels while decreasing the glutathione (GSH) levels and mitochondrial membrane potential (ΔΨm), finally leading to a higher cell apoptotic rate. Moreover, ACR induced U87-MG cell apoptosis and autophagy via ROS-triggered expression in the mitochondrial apoptosis pathway, NF-κB activation, and autophagosome accumulation. In addition, the autophagosome accumulation induced by ACR could probably be ascribed to blocked autophagic flux, inhibiting the autophagosomes from combining with lysosomes, while the inhibition of autophagy caused by ACR further promoted the initiation of apoptosis. In conclusion, the results indicated that the apoptotic and autophagic pathways responded to ACR-induced neurotoxicity. However, inhibited protective autophagy further promoted apoptotic progression. New insights may be derived from these cellular responses that can help develop diverse pathway strategies for assessing the risk posed by ACR.HIGHLIGHTSACR induced mitochondrial- and caspase-dependent apoptosis in U87-MG cells.ACR regulated the autophagic markers and blocked autophagic flux in U87-MG cells.ACR inhibited protective autophagy and promoted apoptotic initiation in U87-MG cells.

Acute exposure to fipronil induces oxidative stress, apoptosis and impairs epithelial homeostasis in the midgut of the stingless bee Partamona helleri Friese (Hymenoptera: Apidae)

Partamona helleri is an important pollinator in natural and agricultural ecosystems in the neotropics. However, the foraging activity of this bee increases its risk of exposure to pesticides, which may affect both the individuals and the colony. Thus, this study aims to evaluate the side effects of LC₅₀ of fipronil (0.28 ng a.i. μL^-1) on the midgut morphology, antioxidant activity and some pathways of cell death, proliferation and differentiation in workers of P. helleri, after 24 h of oral exposure. Fipronil caused morphological alterations in the midgut of the bees. The activities of the detoxification enzymes superoxide dismutase, catalase and glutathione S-transferase increased after exposure, which suggests the occurrence of a detoxification mechanism. Furthermore, exposure to fipronil changed the number of positive cells for signaling-pathway proteins in the midgut of bees, which indicates the induction of cell death by the apoptotic pathway and impairment of the midgut epithelial regeneration. These results demonstrate that fipronil may negatively affect the morphology and physiology of the midgut of the stingless bee P. helleri and impose a threat to the survival of non-target organisms.

Restoration and stabilization of acrylamide-induced DNA, mitochondrial damages and oxidative stress by chrysin in human lymphocyte

BACKGROUND

Acrylamide (AA) is a water-soluble toxic chemical that is considered one of the most important food contaminants. Furthermore, AA is considered a major public health risk.

METHODS

This study was designed to evaluate the effects of AA on cytotoxicity, oxidative damage and genotoxicity in human lymphocytes and also to evaluate the protective effects of the chrysin (CH). Lymphocytes after isolation from the blood were treated with AA (50 µM), AA (50 µM) plus CH (10, 25, 50 µM) and CH (50 µM), and parameters such as cell viability, mitochondrial and lysosomal damage, as well as oxidative damage to DNA were examined.

RESULTS

The results showed that CH was able to reduce cytotoxicity, reactive oxygen species (ROS) levels, lipid peroxidation (LPO) level, collapse in mitochondrial membrane potential (MMP) and oxidative damage of DNA caused by AA in human lymphocytes. Also, co-treatment of the AA-exposed human lymphocytes with CH increases the glutathione (GSH) levels.

CONCLUSION

Results suggest that CH (10, 25, 50 µM) shows a protective role in AA-induced cytotoxicity, oxidative stress, mitochondrial damage and DNA oxidative damage.

MiR-193b-5p protects BRL-3A cells from acrylamide-induced cell cycle arrest by targeting FoxO3

Acrylamide (AA), an important by-product of the Maillard reaction, has been reported to be genotoxic and carcinogenic. The present study employed miRNAs to investigate the toxic mechanism of AA and their role against AA toxicity. Deep sequencing of small RNA libraries was performed and miR-193b-5p was applied for further study. AA significantly reduced the level of miR-193b-5p and its ectopic expression promoted cell cycle G1/S transition and cell proliferation by upregulating the cyclin-dependent kinase regulator Cyclin D1 and downregulating the cyclin-dependent kinase inhibitor p21, while miR-193b-5p inhibitor led to the opposite results. Dual luciferase assay demonstrated miR-193b-5p regulated the expression of FoxO3 by directly targeting the FoxO3 3'-untranslated region (3'-UTR). Knockdown of FoxO3 induced cell cycle G1/S transition and cell proliferation, which was suppressed by the inhibition of miR-193b-5p but promoted by miR-193b-5p mimics. MiR-193b-5p inhibitor strengthened the effect of FoxO3, contrary to the effect of miR-193b-5p mimics. In conclusion, miR-193b-5p acted as a regulator of cell cycle G1/S transition and cell proliferation by targeting FoxO3 to mediate the expression of p21 and Cyclin D1.

Synthesis and Photoactivated Toxicity of 2-Thiophenylfuranocoumarin Induce Midgut Damage and Apoptosis in Aedes aegypti Larvae

Furanocoumarins are photoactive compounds derived from secondary plant metabolites. They possess many bioactivities, including antioxidative, anticancer, insecticidal, and bactericidal activities. Here, we designed a new scheme for synthesizing 2-arylfuranocoumarin derivatives by condensation, esterification, bromination, and Wittig reaction. We found that 2-thiophenylfuranocoumarin (Iy) had excellent photosensitive activity. Three Iy concentrations (LC₂₅, LC₅₀, and LC₇₅) were used to treat the fourth instar larvae of Aedes aegypti (A. aegypti). The photoactivated toxicity, sublethal dose, mitochondrial dysfunction, oxidative stress level, intestinal barrier dysfunction, and apoptosis were studied. The results showed that Iy induced reactive oxygen species (ROS) production in midgut cells under ultraviolet light. Ultrastructural analysis demonstrated that mitochondria were damaged, and the activities of related enzymes were inhibited. Ultimately, Iy exposure led to excessive ROS production followed by the inhibition of antioxidant enzymes, including SOD, CAT, GPx, and GR, which diminished ROS elimination and escalated oxidative stress in midgut cells, aggravating the degree of oxidative damage in these cells. Histopathological changes were observed in the midgut, which led to intestinal barrier dysfunction. When the elimination of ROS was blocked and it accumulated in cells, apoptosis-related genes, including AeDronc, AeCaspase7, and AeCaspase8, were induced and activated. In addition, Iy affected the growth and development of A. aegypti at sublethal concentrations, and there was an obvious post-lethal effect. Thus, we found that Iy caused midgut damage and apoptosis in A. aegypti larvae under ultraviolet light, which preliminarily revealed the mode of action of Iy in A. aegypti.

Acrylamide inhibits autophagy, induces apoptosis and alters cellular metabolic profiles

Acrylamide (ACR) is generated during thermal processing of carbohydrate-rich foods at high temperature and can directly enter the body through ingestion, inhalation and skin contact. The toxicity of ACR has been widely studied. The main results of these studies show that exposure to ACR can cause neurotoxicity in both animals and humans, and show reproductive toxicity and carcinogenicity in rodent animal models. However, the mechanism of toxicity of ACR has not been studied by metabolomics approaches, and the effect of ACR on autophagy remains unknown. Here, U₂OS cell were treated with ACR 6 and 24 h and collected for further study. We have demonstrated that ACR inhibited autophagic flux, and increased ROS content. Accumulation of ROS resulted in increase of apoptosis rates and secretion of inflammatory factors. In addition, significant differences in metabolic profiles were observed between ACR treated and control cells according to multiple analysis models. A total of 73 key differential metabolites were identified. They were involved in multiple metabolic pathways. Among them, exposure to ACR caused glycolysis/gluconeogenesis attenuation by decreasing levels of glycolytic intermediates, reduced the rate of the TCA cycle, while elevating levels of several amino acid metabolites and lipid metabolites. In summary, our study provides useful evidence of cytotoxicity caused by ACR via metabolomics and multiple bioanalytic methods.

Notoginsenoside R1 Protects Against the Acrylamide-Induced Neurotoxicity via Upregulating Trx-1-Mediated ITGAV Expression: Involvement of Autophagy

Acrylamide (ACR) is a common chemical used in various industries and it said to have chronic neurotoxic effects. It is produced during tobacco smoking and is also generated in high-starch foods during heat processing. Notoginsenoside R1 (NR1) is a traditional Chinese medicine, which is used to improve the blood circulation and clotting. The objective of this study was to investigate the mechanism of ACR-triggered neurotoxicity and to identify the protective role of NR1 by upregulating thioredoxin-1 (Trx-1). Our results have shown that NR1 could block the spatial and cognitive impairment caused by ACR administration. Bioinformatics analysis revealed that Trx-1 regulated autophagy via Integrin alpha V (ITGAV). NR1 could resist the ACR-induced neurotoxicity by upregulating thioredoxin-1 in PC12 cells and mice. The autophagy-related proteins like autophagy-related gene (ATG) 4B, Cathepsin D, LC3 II, lysosomal-associated membrane protein 2a (LAMP2a), and ITGAV were restored to normal levels by NR1 treatment in both PC12 cells and mice. Besides, we also found that overexpression of Trx-1 resisted ACR-induced autophagy in PC12 cells and downregulation of Trx-1 triggered autophagy induced by ACR in PC12 cells. Therefore, it could be concluded that Trx-1 was involved in the autophagy pathway. Besides, we also found that ITGAV was an intermediate node linking Trx-1 and the autophagy pathway.

Clarithromycin effectively enhances doxorubicin-induced cytotoxicity and apoptosis in MCF7 cells through dysregulation of autophagy

PURPOSE

Use of autophagy inhibitors in combination with chemotherapy has become a novel chemotherapeutic strategy. In this study, we aimed to determine whether the effectiveness of doxorubicin (DOX) is augmented by clarithromycin (CAM) in MCF7 cells and the molecular mechanisms involved.

MATERIALS AND METHODS

Combined cytotoxicity of CAM and DOX was assessed by MTT assay and was analyzed using the Chou-Talalay's method. To clarify the underlying mechanisms, several factors, including apoptosis (Annexin V/propidium iodide staining), intracellular level of DOX (spectrofluorimetry) and P-glycoprotein activity (Rhodamin 123 efflux assay) were measured. In addition, autophagy was evaluated by intracellular labeling with anti-LC3II and LysoTrackerGreen (LTG) staining and analyzed by flowcytometry.

RESULTS

The anti-proliferation effect of DOX was synergistically enhanced by CAM in MCF7 cells and was associated with an increase in the apoptotic cell death. However, the intracellular level of DOX remained unchanged in the presence of CAM. Based on the findings, 100 μM of CAM did not exhibit any inhibitory effects on P-glycoprotein activity. Flow cytometric analysis indicated that DOX at IC₂₀ concentration induced the autophagy flux, as confirmed by the increased level of LC3II and LTG signals. Moreover, combined treatment with DOX and CAM resulted in more pronounced LTG signals, but no change in LC3II. These results indicate that CAM blocks the autophagy flux induced by DOX.

CONCLUSIONS

These findings suggest that suppression of autophagy by CAM may promote chemotherapeutic outcome in breast cancer. However, further investigations are needed to evaluate the application of CAM in adjuvant breast cancer therapy.

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.

Protective effect of seabuckthorn berry juice against acrylamide-induced oxidative damage in rats

Acrylamide (AA), classified as a probable carcinogen, can be neurotoxic, genotoxic, and can damage DNA. This study explored the ability of seabuckthorn berries juice (SBJ) to alleviate AA-induced toxic injury in rats. Twenty-four adult male Sprague-Dawley (SD) rats were randomly divided into four groups: control group, AA group (40 mg/kg), AA + SBJ (40 mg/kg AA and 5 mL/kg SBJ), and AA + vitamin C (VC) group (positive control group, 40 mg/kg AA and 100 mg/kg VC). At the end of the experiment, rats in AA group showed a marked decrease in the rate of weight gain, hind extremity abduction, and ataxia. Obvious anomalies were seen in plasma biochemical parameters (P < 0.05), and different degrees of injury were observed upon histological examination of five tissues (hippocampus, cerebellum, liver, small intestine, and kidney). Compared to the control group, levels of superoxide dismutase, catalase, and glutathione were significantly decreased, while malondialdehyde was elevated (P < 0.05). SBJ treatment reduced the abnormal of behavior, hematological index, antioxidant enzyme, and tissue damage caused by AA in rats. PRACTICAL APPLICATION: Seabuckthorn berries are wild berries rich in vitamin C and polyphenols, which have good antioxidant properties. In this experiment, SBJ has a significant alleviating effect on AA-induced oxidative damage in rats. Therefore, we speculate that SBJ may relieve the oxidative damage caused by diet or other forms of AA exposure in the general population. At the same time, this experiment also provides new ideas for alleviating AA-induced in vivo toxicity.

Mitochondrial toxicity of nanomaterials

In recent years, nanomaterials have been widely applied in electronics, food, biomedicine and other fields, resulting in increased human exposure and consequent research focus on their biological and toxic effects. Mitochondria, the main target organelle for nanomaterials (NM), play a critical role in their toxic activities. Several studies to date have shown that nanomaterials cause alterations in mitochondrial morphology, mitochondrial membrane potential, opening of the mitochondrial permeability transition pore (MPTP) and mitochondrial respiratory function, and promote cytochrome C release. An earlier mitochondrial toxicity study of NMs additionally reported induction of mitochondrial dynamic changes. Here, we have reviewed the mitochondrial toxicity of NMs and provided a scientific basis for the contribution of mitochondria to the toxicological effects of different NMs along with approaches to reduce mitochondrial and, consequently, overall toxicity of NMs.

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.

Prospective role of mitochondrial apoptotic pathway in mediating GMG-ITC to reduce cytotoxicity in H2O2-induced oxidative stress in differentiated SH-SY5Y cells

The antioxidant and neuroprotective activity of Glucomoringin isothiocyanate (GMG-ITC) have been reported in in vivo and in vitro models of neurodegenerative diseases. However, its neuroprotective role via mitochondrial-dependent pathway in a noxious environment remains unknown. The main objective of the present study was to unveil the mitochondrial apoptotic genes' profile and prospectively link with neuroprotective activity of GMG-ITC through its ROS scavenging. The results showed that pre-treatment of differentiated SH-SY5Y cells with 1.25 μg/mL purified isolated GMG-ITC, significantly reduced reactive oxygen species (ROS) production level, compared to H₂O₂ control group, as evidenced by flow cytometry-based evaluation of ROS generation. Presence of GMG-ITC prior to development of oxidative stress condition, downregulated the expression of cyt-c, p53, Apaf-1, Bax, CASP3, CASP8 and CASP9 genes with concurrent upregulation of Bcl-2 gene in mitochondrial apoptotic signalling pathway. Protein Multiplex revealed significant decreased in cyt-c, p53, Apaf-1, Bax, CASP8 and CASP9 due to GMG-ITC pre-treatment in oxidative stress condition. The present findings speculated that pre-treatment with GMG-ITC may alleviate oxidative stress condition in neuronal cells by reducing ROS production level and protect the cells against apoptosis via neurodegenerative disease potential pathways.

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.

Therapeutic effect of curcumin on acrylamide-induced apoptosis mediated by MAPK signaling pathway in Leydig cells

The aim of this study was to investigate the possible therapeutic effects of curcumin (CUR), against acrylamide (AA)-induced toxic effects on Leydig cells. The AA and CUR-treated cells were evaluated for cell viability, lipid peroxidation, reactive oxygen species (hydroxyl radical and hydrogen peroxide), antioxidant levels (glutathione peroxidase, glutathione-S-transferase, and catalase), apoptosis/necrosis rates and phosphorylation status of mitogen-activated protein kinases (MAPKs). Leydig cells were exposed to four concentrations of AA (1, 10, 100, 1000 µM) in the presence and absence of CUR (2.5 µM) for 24 hours. According to the present result, AA concentration-dependently, increased the oxidative stress parameters and suppressed the antioxidant enzyme levels, meanwhile induced apoptosis and activated the phosphorylation of extracellular signal-regulated kinase, p38, and c-Jun NH ₂ -terminal kinase. Moreover, CUR ameliorated the detrimental effects of AA. Thus, AA-induced apoptosis through activation of the MAPK signaling pathway and CUR has a protective effect against AA-induced damage in Leydig cells.

Effects of long term oral acrylamide administration on alpha naphthyl acetate esterase and acid phosphatase activities in the peripheral blood lymphocytes of rats

Acrylamide is an important industrial chemical; it also is formed in starch-rich foodstuffs during baking, frying and roasting. Most acrylamide exposure occurs by ingestion of processed foods. We investigated possible immunotoxic effects of extended administration of low doses of acrylamide in rats. To do this, we measured alpha-naphthyl acetate esterase (ANAE) and acid phosphatase (ACP-ase) activities in peripheral blood lymphocytes. Male and female weanling Wistar rats were administered 2 or 5 mg acrylamide/kg/day in drinking water for 90 days. Peripheral blood was sampled at the end of the administration period. We found ANAE staining in eosinophils and T-lymphocytes, but not in monocytes, platelets, B-lymphocytes and neutrophils. ACP-ase was found in B-lymphocytes. We found a significant reduction of the ratio of ANAE:ACP-ase in lymphocytes of the experimental animals compared to controls. We found no statistically significant differences between the doses or sexes. We found that acrylamide ingested in processed foods might affect the immune system adversely by decreasing the population of mature T- and B-lymphocytes.

Xihuang Pill Induces Apoptosis of Human Glioblastoma U-87 MG Cells via Targeting ROS-Mediated Akt/mTOR/FOXO1 Pathway

Xihuang pill (XHP), a traditional Chinese herbal formula, has long been used as an effective agent against multiple tumors. The aim of this study is to evaluate the effects of XHP on the growth inhibition and apoptosis in glioblastoma U-87 MG cells. Gas chromatography-mass spectrometry (GC-MS) was performed for constituent analysis of XHP. Cell viability, cell cycle arrest, generation of reactive oxygen species (ROS), and apoptosis were measured by CCK-8 assay, PI/RNase staining, DCFH-DA assay, TUNEL assay, Annexin V-FITC/PI double staining, and JC-1 assay, respectively. The role of XHP in the regulation of Akt/mTOR/FOXO1 interaction was clarified by using Western Blotting (WB), immunofluorescence (IF), pharmacological inhibitor or antioxidant, and siRNA silencing. The results suggested that XHP could inhibit U-87 MG cells growth and arrest cells in S-phase cell cycle significantly and that the generation of ROS, collapse of mitochondrial membrane potential, enhancement of Bax/Bcl-xL ratio, and reduction of the precursor forms of caspase-9 and caspase-3 caused by XHP prompted that a ROS-mediated mitochondria-dependent apoptosis was possibly involved. Furthermore, XHP affected the Akt/mTOR/FOXO1 pathway via inhibiting the phosphorylation of Akt, mTOR, and FOXO1 and increasing both prototype and nuclear translocation of FOXO1. Inhibition of Akt, mTOR, and FOXO1 by specific inhibitors or siRNA could interpose the apoptotic induction. In conclusion, we demonstrate for the first time that XHP may regulate glioblastoma U-87 MG cell apoptosis via ROS-mediated Akt/mTOR/FOXO1 pathway.

Cerium oxide nanoparticles protects against acrylamide induced toxicity in HepG2 cells through modulation of oxidative stress

Acrylamide (AA) is a toxic chemical compound found in cooked foods. Considerable evidences suggest that oxidative stress and mitochondrial dysfunction are contributed to AA toxicity. Ceric oxide (CeO₂) nanoparticles (nano-ceria) have the potential to be developed as a therapeutic for oxidative stress insults due to their catalytic antioxidant properties. In this study we investigated, whether nano-ceria exerted a protective effect against AA-induced cytotoxicity and oxidative damage. HepG2 human cancer cell lines were exposed to nano-ceria (50, 100, and 200 µM) and after 30 min, AA in the half maximal inhibitory concentration (IC50) concentration (200 µM) was added to the cells. Twenty four hours later, cellular viability, reactive oxygen species (ROS) generation, lipid peroxidation (LPO), and cellular levels of glutathione (GSH) were assayed. AA decreased cell viability and pretreatment with nano-ceria significantly decreased AA-induced cytotoxicity. In addition, nano-ceria alleviated AA-induced ROS generation and LPO and depressed GSH level. Our results suggested that nano-ceria prevented cellular and oxidative damage induced by AA.

Alpha lipoic acid exerts antioxidant effect via Nrf2/HO-1 pathway activation and suppresses hepatic stellate cells activation induced by methotrexate in rats

Hepatic injury is a major side effect associated with methotrexate (MTX) therapy resulting from inflammatory reactions and oxidative stress induction. Therefore, liver fibrosis incidence is augmented with long-term MTX therapy. Alpha lipoic acid (ALA) is a naturally occurring compound with potent antioxidant activity. This study explored the hepatoprotective mechanisms of ALA against MTX-induced hepatic injury in rats. Hepatic injury was induced in MTX group by 20 mg/kg body weight ip. injection of MTX. ALA group was pretreated with ALA 60 mmol/kg body weight ip. for five days followed by a single dose of MTX in the sixth day. Blood samples and liver tissues were then obtained to assess several biochemical parameters as serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), reduced glutathione (GSH), total antioxidant capacity (TAC) and lipid peroxidation. Nuclear factor E2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) pathway was studied by determining the extent of mRNA Nrf2 expression and the level of HO-1. Hepatic stellate cells (HSCs) activation was evaluated by estimating the expression of α-smooth muscle actin (α-SMA) and hydroxyproline content. Also, tumor necrosis factor alpha (TNF-α), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and caspase-3 were assessed by ELISA in addition to histopathological examination of liver samples. Results showed that ALA pretreatment improved liver function since serum ALT, AST and ALP levels were reduced. Additionally, ALA restored GSH and TAC levels when compared to MTX group and decreased lipid peroxidation. ALA exerted its antioxidant effect via Nrf2/HO-1 pathway as well as it showed anti-inflammatory and antiapoptotic effects by reducing TNF-α, iNOS, COX-2 and caspase-3 levels in liver tissue homogenate. Finally, ALA suppressed HSCs activation by decreasing α-SMA expression and hydroxyproline content in liver. It was concluded that ALA has hepatoprotective effects against MTX-induced hepatic injury mediated by Nrf2/HO-1 pathway as well as anti-inflammatory and antiapoptotic properties.