Effects of endocrine disruptor furan on reproductive physiology of Sprague Dawley rats: An F1 Extended One-Generation Reproductive Toxicity Study (EOGRTS)

MAGI2-AS3 hypermethylated in promoter region promotes migration and invasion of head and neck squamous cell carcinoma via miRNA-31-5p/AR axis

Molecular regulatory mechanism of MAGI2-AS3 in HNSCC is not yet mature.In this study, we analyzed the methylation level of MAGI2-AS3 promoter and its downstream miR-31-5p/AR axis by bioinformatics methods. qRT-PCR was used to detect the mRNA expression level of each gene, and western blot was used to detect the expression level of AR proteins in tissues and cells. CCK-8, colony formation, wound healing, and cellular invasion assays were used to detect the HNSCC cell proliferation, migration, and invasion. Dual luciferase and RIP assays were performed to validate the binding relationship between genes. The effect of MAGI2-AS3 on HNSCC progression was verified in nude mice in vivo. The low expression of MAGI2-AS3 in HNSCC was caused by hypermethylation of MAGI2-AS3, which could regulate the target of miR-31-5p by sponge adsorption of miR-31-5p, and miR-31-5p could inhibit the expression of AR by directly targeting AR. Thus, MAGI2-AS3 could inhibit the proliferation, migration, and invasion of HNSCC through the miR-31-5p/AR axis. This provided a theoretical basis that MAGI2-AS3 was a potential therapeutic target for HNSCC.

Demystifying furan formation in foods: Implications for human health, detection, and control measures: A review

Furan (C₄H₄O), an unintended hazardous compound, is formed in various thermally processed foods through multiple pathways, raising concerns due to its potential carcinogenicity in humans. The aim of this comprehensive review was to synthesize and evaluate the latest research on furan, from its formation by different precursors to its presence in diverse food matrices, as well as the emerging methods for its detection and mitigation. Emphasizing the toxicity of furan, it explored evidence from in vitro and in vivo studies, including reproductive toxicity, carcinogenic effects, and related biomarkers. Additionally, this review focused on human risk assessments of furan exposure and discussed innovative research approaches to better understand its health risks. By consolidating current knowledge, this review provided a comprehensive perspective on furan's impact on human health and suggested future research directions to further research on furan.

The impact of furan exposure on steroidogenesis in Leydig cells: cellular and molecular observations

BACKGROUND

Furan is an organic compound that occurs as a result of heat treatment during the processing and cooking of many food products. Furthermore, the environment contains furan in tobacco smoke and vehicle exhaust gases, and it serves as an intermediate molecule in the synthesis of various pharmaceutical and chemical agents, pesticides, and stabilizers. Studies on the male reproductive system have not been able to elucidate the pathway through which furan exerts its negative effects.

METHODS AND RESULTS

In this study, the TM3 Leydig cell line was exposed to various furan concentrations (0.03, 0.3, and 3 mM) for 24 h. In order to assess the cytotoxic effects of furan on Leydig cells, we examined cell viability, cell proliferation, and lactate dehydrogenase enzyme levels. To investigate the detrimental effects of furan on testosterone biosynthesis, quantitative analyses were conducted on cAMP and testosterone levels, as well as the expression levels of key genes and transcription factors implicated in the steroidogenic pathway. The results indicate that furan inhibited the viability and proliferation of Leydig cells and enhanced the activity of lactate dehydrogenase. Leydig cells administered to furan exhibited notable reductions in cAMP and testosterone levels. Additionally, while the expression levels of steroidogenic genes were downregulated, significant changes were detected in the expression levels of the transcription factors responsible for the regulation of these genes.

CONCLUSIONS

Consequently, our findings suggest that furan exerts inhibitory effects on steroidogenesis in Leydig cells through multiple mechanisms, ultimately leading to infertility by inducing dysfunction in Leydig cells.

Mitigating effect of pomegranate peel extract against the furan induced testicular injury by apoptosis, steroidogenic enzymes and oxidative stress

Furan is generated in a wide array of heat-treated foods through thermal degradation, leading to severe impairments in the male reproductive system. The main objective of this study was to investigate the potential of pomegranate peel extract (PGPE) in mitigating testicular dysfunctions induced by furan. Male rats were categorized into four groups: control/untreated, PGPE, furan, and PGPE + furan group. The study results revealed that furan-treated rats exhibited significantly elevated aminotransferase and phosphatase activity, and also generated increased oxidative stress, and reduced antioxidative stress protein activity. Additionally, protein content levels (ALT, AST, ALP, and ACP) and activities of steroidogenic Leydig cell hydroxysteroid dehydrogenase (3β-HSD and 17β-HSD) enzymes were significantly decreased. Significant variations in testicular parameters, apoptotic genes (Bcl-2, P53, and Caspase3), inflammatory and anti-inflammatory cytokines (IL1β, IL10), male sex hormones follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and sperm quality were also observed. Furthermore, testicular histological abnormalities were confirmed by biochemical and molecular modifications. Notably, PGPE pre-treated furan-intoxicated animals exhibited significant improvements in most of the assessed parameters compared to furan-treated groups. In conclusion, PGPE presents essential preventive measures and a novel pharmacological potential therapy against furan-induced testicular injury.

Rewiring cis-2-butene-1,4-dial mediated urinary metabolomics fingerprints of short-term exposure to furan

Furan represents one of the dietary-sourced persistent organic pollutants and thermal processing contaminants. Given its widespread occurrence in food and various toxicological effects, accurately assessing furan exposure is essential for informing public health risks. Furan is metabolized to a reactive primary product, cis-2-butene-1,4-dial (BDA) upon absorption. Some of the resulting BDA-derived metabolites have been proposed as potential exposure biomarkers of furan. However, the lack of quantification for recognized and feasible furan biomarkers has hampered the development of internal exposure risk assessment of furan. In this study, we employed reliable non-targeted metabolomics techniques to uncover urinary furan metabolites and elucidate their chemical structures. We characterized 8 reported and 11 new furan metabolites derived from the binding of BDA with glutathione (GSH), biogenic amines, and/or amino acids in the urine of male rats subjected to varying doses of furan. Notably, a mono-GSH-BDA adduct named cyclic GSH-BDA emerged as a highly prospective specific biomarker of furan exposure, as determined by an ultrahigh-performance liquid chromatography-tandem mass spectrometry method. Cyclic GSH-BDA demonstrated a robust mass spectrometry ion response intensity and exhibited evident time- and dose response. Additionally, we conducted a comprehensive profiling of the kinetics of potential furan biomarkers over time to capture the metabolic dynamics of furan in vivo. Most urinary furan metabolites reached peak concentrations at either the first (3 h) or second (6 h) sampling time point and were largely eliminated within 36 h following furan treatment. The present study provides novel insights into furan metabolism and sheds light on the biomonitoring of furan exposure.

Comparative genomic analysis of Fischer F344 rat livers exposed for 90 days to 3-methylfuran or its parental compound furan

Furan is a naturally forming compound found in heat-processed foods such as coffee, canned meats, and jarred baby food. It is concurrently found with analogues including 2-methylfuran (2-MF) and 3-methylfuran (3-MF), and toxicity studies demonstrate all are potent liver toxins. Toxicity studies found 3-MF is more toxic than either furan, or 2-MF. The present analysis assesses the transcriptional response in liver samples taken from male Fischer (F344) rats exposed to furan or 3-MF from 0 to 2.0 and 0-1.0 mg/kg bw/day, respectively, for 90 days. Transcriptional analyses found decreased liver function and fatty acid metabolism are common responses to both furan and 3-MF exposure. Furan liver injury promotes a ductular reaction through Hippo and TGFB signalling, which combined with increased immune response results in ameliorating perturbed bile acid homeostasis in treated rats. Failure to activate these pathways in 3-MF exposed rats and decreased p53 activity leads to cholestasis, and increased toxicity. Finally, BMD analysis indicate many of the most sensitive pathways affected by furan and 3-MF exposure relate to metabolism - malate dehydrogenase and glucose metabolism with BMDLs of 0.03 and 0.01 mg/kg bw/day for furan and 3-MF exposure, respectively, which agrees with BMDLs previously reported for apical and microarray data.

Furan promotes cytotoxic effects through DNA damage and cell apoptosis in Leydig cells

Furan is an organic chemical that can cause adverse effects on human health and is formed as a result of the thermal decomposition of many food components during cooking, storage, and processing techniques. Studies have shown that exposure to furan causes nephrotoxicity, hepatotoxicity, immunotoxicity, and reproductive toxicity. According to our current knowledge of the literature, the genotoxic mode of action of furan is highly controversial. The genotoxic effects of furan on the male reproductive system, however, have not been studied. In this study, the TM3 Leydig cell line was treated with 750, 1500, and 3000 μM concentrations of furan for 24 h. Following the completion of the exposure period, the cytotoxicity of furan in TM3 Leydig cells was assessed using a cell viability assay and a spectrophotometric measurement of lactate dehydrogenase (LDH) enzyme levels. The double fluorescence staining method was used to demonstrate furan-induced apoptosis, and DNA damage was shown using the micronucleus, comet, and chromosomal aberration assays. The result indicated that furan administration of Leydig cells resulted in an increase in structural chromosomal aberration, comet, and micronucleus formation, reduced cell viability, increased LDH activity, and a higher incidence of apoptotic cells. These findings revealed that furan induces DNA damage in TM3 Leydig cells, causing genotoxicity and DNA damage-induced cytotoxicity.

Eriodictyol attenuates Furan induced testicular toxicity in Rats: Role of oxidative stress, steroidogenic enzymes and apoptosis

Furan (C₄H₄O) is a naturally occurring organic compound. It develops as a result of the thermal processing of food and stimulates critical impairments in male reproductive tract. Eriodictyol (Etyol) is a natural dietary flavonoid possessing diverse pharmacological potentials. The recent investigation was proposed to ascertain the ameliorative potential of eriodictyol against furan-instigated reproductive dysfunctions. Male rats (n = 48) were classified into 4 groups: untreated/control, furan (10 mg/kg), furan+ eriodictyol (10 mg/kg + 20 mg/kg) and eriodictyol (20 mg/kg). At the 56th day of the trial, the protective effects of eriodictyol were evaluated by assessing various parameters. Results of the study revealed that eriodictyol attenuated furan-induced testicular toxicity in the biochemical profile by increasing catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) along with glutathione reductase (GSR) activities, whereas reduced the reactive oxygen species (ROS) along with malondialdehyde (MDA) levels. It also restored the normal state of sperm motility, viability, the count of hypo-osmotic tail swelled sperm as well as epididymal sperm number along with reduced sperm anomalies (morphological) tail, mid-piece and head. Furthermore, it elevated the decreased levels of luteinizing hormone (LH), plasma testosterone and follicle-stimulating hormone (FSH) as well steroidogenic enzymes (17β-HSD, StAR protein & 3β-HSD) and testicular anti-apoptotic marker (Bcl-2) expression, whereas, down-regulating apoptotic markers (Bax & Caspase-3) expression. Eriodictyol treatment also effectively mitigated the histopathological damages. The outcomes of the current study provide fundamental insights into the ameliorative potential of eriodictyol against furan-instigated testicular toxicity.

Dietary phytoestrogen diosgenin interrupts metabolism, physiology, and reproduction of Swiss albino mice: Possible mode of action as an emerging environmental contaminant, endocrine disruptor and reproductive toxicant

Dietary phytoestrogens are the main source of environmental contamination due to their estrogen-mimicking and endocrine-disrupting effects, posing a threat to microbial, soil, plant, and animal health. Diosgenin, a phytosteroid saponin, is used in many traditional medicines, nutraceuticals, dietary supplements, contraceptives, and hormone replacement therapies against numerous diseases and disorders. It is important to be aware of the potential risks associated with diosgenin, as well as its potential to cause reproductive and endocrine toxicity. Due to the lack of research on the safety and probable adverse side effects of diosgenin, this work evaluated the endocrine-disrupting and reproductive toxicity of diosgenin in albino mice by following acute toxicity (OECD-423), repeated dose 90-day oral toxicity (OECD-468), and F₁ extended one-generation reproductive toxicity (OECD-443) studies. Diosgenin was found to be slightly toxic, with LD₅₀ for male and female mice being 546.26 and 538.72 mg/kg, respectively. Chronic exposure of diosgenin (10, 50, 100, and 200 mg/kg) generated oxidative stress, depleted antioxidant enzymes, disturbed homeostasis of the reproductive hormones, and interrupted steroidogenesis, germ cell apoptosis, gametogenesis, sperm quality, estrous cycle, and reproductive performance in the F₀ and F₁ offspring. Long-term oral exposure of diosgenin to the mice disturbed the endocrine and reproductive functions and generated transgenerational reproductive toxic effects in F₀ and F₁ offspring. These results suggest that diosgenin should be used carefully in food products and medical applications due to its potential endocrine-disrupting and reproductive toxic effects. The findings of this study provide a better understanding of the potential adverse effects of diosgenin and the need for appropriate risk assessment and management of its use.

A comprehensive review of furan in foods: From dietary exposures and in vivo metabolism to mitigation measures

Furan is a thermal food processing contaminant that is ubiquitous in various food products such as coffee, canned and jarred foods, and cereals. A comprehensive summary of research progress on furan is presented in this review, including discussion of (i) formation pathways, (ii) occurrence and dietary exposures, (iii) analytical techniques, (iv) toxicities, (v) metabolism and metabolites, (vi) risk assessment, (vii) potential biomarkers, and (viii) mitigation measures. Dietary exposure to furan varies among different countries and age groups. Furan acts through various toxicological pathways mediated by its primary metabolite, cis-2-butene-1,4-dial (BDA). BDA can readily react with glutathione, amino acids, biogenic amines, or nucleotides to form corresponding metabolites, some of which have been proposed as potential biomarkers of exposure to furan. Present risk assessment of furan mainly employed the margin of exposure approach. Given the widespread occurrence of furan in foods and its harmful health effects, mitigating furan levels in foods or exploring potential dietary supplements to protect against furan toxicity is necessary for the benefit of food safety and public health.

Accidental lead in contaminated pipe-borne water and dietary furan intake perturbs rats' hepatorenal function altering oxidative, inflammatory, and apoptotic balance

Inadvertent exposure to furan and Pb is associated with hepatorenal abnormalities in humans and animals. It is perceived that these two chemical species may work in synergy to orchestrate liver and kidney damage. Against this background, we investigated the combined effect of furan and incremental lead (Pb) exposure on hepatorenal dysfunction. Wistar rats (n = 30; 150 g) were treated for 28 days accordingly: Control; FUR (8 mg/kg), PbAc (100 µg/L), FUR + PbAc₁ (8 mg/kg FUR + 1 µg/L PbAc); FUR + PbAc₁ (8 mg/kg FUR + 10 µg/L PbAc), and FUR + PbAc₁ (8 mg/kg FUR + 100 µg/L PbAc). Biomarkers of hepatorenal function, oxidative stress, inflammation, DNA damage, and apoptosis were examined. Furan and incrementally Pb exposure increased the levels of hepatorenal biomarkers and oxidative and pro-inflammatory mediators, including lipid peroxidation, reactive oxygen and nitrogen species, and interleukin-1 beta. Increased DNA damage, caspases- 9 and -3, and atypical histoarchitecture of the hepatorenal tissues exemplified furan and Pb treatment-related perturbations. Furthermore, the levels of antioxidants and IL-10 were also suppressed. Furan and Pb dose-dependently exacerbated hepatorenal derangements by altering the redox and inflammatory rheostats, worsened DNA damage, and related apoptotic onset that may potentiate hepatorenal disorders in humans and animals. The findings validate the synergistic effect of furan and Pb in the pathophysiology of kidney and liver disorders.