3-Monochloropropane-1,2-diol esters induce HepG2 cells necroptosis via CTSB/TFAM/ROS pathway.

3-monochloropropane-1,2-diol esters (3-MCPDE) are toxic substances that form in food thermal processing and have a diverse range of toxicities. In this study, we found that 3-MCPDE triggered necroptosis by RIPK1/RIPK3/MLKL pathway in HepG2 cells. Previous studies have shown that ROS is an important activator of RIPK1 and RIPK3. The data showed that 3-MCPDE induced excessive ROS production through mitochondrial damage. After treatment with ROS inhibitor N-acetylcysteine (NAC), 3-MCPDE-induced necroptosis was relieved. Further, we explored how 3-MCPDE destroys mitochondria. The data suggested that 3-MCPDE induced mitochondrial dysfunction through the CTSB/TFAM pathway. Overall, the results indicated that 3-MCPDE induced necroptosis through CTSB/TFAM/ROS pathway in HepG2 cells. Our study provided a new mechanism for 3-MCPDE hepatotoxicity.

Alleviating 3-MCPD-induced male reproductive toxicity: Mechanistic insights and resveratrol intervention.

3-Monochloropropane-1, 2-diol (3-MCPD), a food-borne contaminant, is widely regarded as the primary cause of male infertility. At present, identifying a method to improve/reduce the male reproductive toxicity caused by 3-MCPD is important. In our study, we explored the potential application of resveratrol (RSV) in mitigating the adverse effects of 3-MCPD. Using 7-week-old Sprague-Dawley (SD) rats as animal models, we investigated the impacts and underlying mechanisms of 3-MCPD and RSV on reproductive function. The administration of 3-MCPD led to significant reductions in testicular and epididymal weights, as well as disruptions in spermatogenesis and histological abnormalities. However, co-treatment with RSV and 3-MCPD mitigated these adverse effects. In vitro study, RSV exhibited the ability to reverse the decline in Leydig and Sertoli cell populations inflicted by 3-MCPD treatment. Mechanistically, RSV reduced endoplasmic reticulum stress (PARP), inflammasome activation (NLRP3), and autophagy-mediated lysosome dysfunction (p62 and LC3BII) induced by 3-MCPD. In addition, 3-MCPD treatment increased the expression level of steroidogenesis-related proteins, steroidogenic acute regulatory (StAR) and CYP11A1, but RSV normalized StAR expression. Moreover, 3-MCPD-induced pro-inflammatory responses were counteracted by RSV treatment, with the cytokine reduction and modulation of CD206 expression, a marker of macrophage activation. These findings indicate that RSV attenuates 3-MCPD-induced reproductive toxicity, highlighting its application potential as an adjuvant agent for male reproductive health.

Newly discovered developmental and ovarian toxicity of 3-monochloro-1,2-propanediol in Drosophila melanogaster and cyanidin-3-O-glucoside's protective effect.

3-Monochloro-1,2-propanediol (3-MCPD) is a pervasive environmental pollutant that is unintentionally produced during industrial production and food processing. Although some studies reported the carcinogenicity and male reproduction toxicity of 3-MCPD thus far, it remains unexplored whether 3-MCPD hazards to female fertility and long-term development. In this study, the model Drosophila melanogaster was employed to evaluate risk assessment of emerging environmental contaminants 3-MCPD at various levels. We found that flies on dietary exposure to 3-MCPD incurred lethality in a concentration- and time-dependent way and interfered with metamorphosis and ovarian development, resulting in developmental retardance, ovarian deformity and female fecundity disorders. Mechanistically, 3-MCPD caused redox imbalance observed as a drastically increased oxidative status in ovaries, confirmed by increased reactive oxygen species (ROS) and decreased antioxidant activities, which is probably responsible for female reproductive impairments and developmental retardance. Intriguingly, these defects can be substantially prevented by a natural antioxidant, cyanidin-3-O-glucoside (C3G), further confirming a critical role of ovarian oxidative damage in the developmental and reproductive toxicity of 3-MCPD. The present study expanded the findings that 3-MCPD acts as a developmental and female reproductive toxicant, and our work provides a theoretical basis for the exploitation of a natural antioxidant resource as a dietary antidote for the reproductive and developmental hazards of environmental toxicants that act via increasing ROS in the target organ.

Toxicology of 3-monochloropropane-1,2-diol and its esters: a narrative review.

3-Monochloropropane-1,2-diol (3-MCPD) is a chiral molecule naturally existing as a racemic mixture of (R)- and (S)-enantiomers. It was thoroughly investigated during the 1970s as a male antifertility drug until research was abandoned because of the side effects observed in toxicity studies. More than 20 years later, 3-MCPD, both in the free form and esterified to the fatty acids, was detected in vegetable oil and discovered to be a widespread contaminant in different processed foods. This review summarises the main toxicological studies on 3-MCPD and its esters. Current knowledge shows that the kidney and reproductive system are the primary targets of 3-MCPD toxicity, followed by neurological and immune systems. Despite uncertainties, in vivo studies suggest that renal and reproductive toxicity is mediated by toxic metabolites, leading to inhibition of glycolysis and energy depletion. Few acute, short-term, and subchronic toxicity studies have investigated the 3-MCPD esters. The pattern of toxicity was similar to that of free 3-MCPD. Some evidence suggests that the toxicity of 3-MCPD diesters may be milder than 3-MCPD, likely because of an incomplete enzymatic hydrolysis in the equivalent free form in the gastrointestinal tract. Further research to clarify absorption, metabolism, and long-term toxicity of 3-MCPD esters would be pivotal to improve the risk assessment of these compounds via food.

3-MCPD as contaminant in processed foods: State of knowledge and remaining challenges.

3-Chloro-1,2-propanediol (3-MCPD) and its fatty acid esters (FE) are present as contaminants in different processed foods. Based on the available toxicological data the potential risk of 3-MCPD and its FE to human health was assessed by risk assessment authorities, including the European Food Safety Authority (EFSA). Considering the available data, EFSA concluded that 3-MCPD is a non-genotoxic compound exhibiting secondary carcinogenic effects in rodents. A tolerable daily intake of 2 µg/kg body weight and day was derived by EFSA for free and ester-bound 3-MCPD in 2018. However, there are still different pending issues that have remained unclear until now. Here, we summarize the current knowledge regarding 3-MCPD and its FE with a focus on pending issues regarding exposure assessment via biomarkers as well as the identification of (toxic) metabolites formed after exposure to FE of 3-MCPD and their modes of action.

Development of physiologically based toxicokinetic models for 3-monochloropropane-1,2-diol and glycidol.

3-Monochloropropane-1,2-diol (3-MCPD), glycidol, together with their fatty acid esters are commonly presented in various food and have shown carcinogenicity in various laboratory animals. Public health risk assessment of 3-MPCD and glycidol exposure relies on quantitative tools that represent their in vivo toxicokinetics. In order to better understand the absorption, distribution, metabolism, and excretion profiles of 3-MCPD and glycidol in male rats, a physiologically based pharmacokinetic (PBTK) model was developed. The model's predictive power was evaluated by comparing in silico simulations to in vivo time course data obtained from experimental studies. Results indicate that our PBTK model successfully captured the toxicokinetics of both free chemicals in key organs, and their metabolites in accessible biological fluids. With the validated PBTK model, we then gave an animal-free example on how to extrapolate the toxicological knowledge acquired from a single gavage to a realistic dietary intake scenario. Three biomarkers, free compound in serum, urinary metabolite DHPMA, and glycidol-hemoglobin adduct (diHOPrVal) were selected for in silico simulation following constant dietary intakes, and their internal levels were correlated with proposed external daily exposure via reverse dosimetry approaches. Taken together, our model provides a computational approach for extrapolating animal toxicokinetic experiments to biomonitoring measurement and risk assessment.

Autophagy and mitochondrial dynamics contribute to the protective effect of diosgenin against 3-MCPD induced kidney injury.

3-Chloro-1, 2-propanediol (3-MCPD) is a widespread food contaminant with kidney as the main target organ. The exploration of ingredients as intervention strategy towards 3-MCPD induced nephrotoxicity is needed. Diosgenin (DIO) is a steroidal saponin presented in several plants and foods. Here we assessed whether DIO attenuates nephrotoxicity induced by 3-MCPD using Human embryonic kidney 293 (HEK293) cells and Sprague-Dawley (SD) rats. The results showed that DIO (2, 6, 8 µM) increased cell viability and exerted inhibitory effect on caspase 3 and caspase 9 activities. Histological examination of rats showed that 15 mg/kg bw DIO ameliorated renal pathological changes caused by 3-MCPD (30 mg/kg bw). DIO also induced autophagy and the blockade of autophagy with 3-Methyladenine (3-MA) aggravated mitochondrial apoptosis induced by 3-MCPD in HEK293 cells. Moreover, treatment with DIO caused an increase in p-LKB1/LKB1 and p-AMPK/AMPK expressions and a decrease in p-mTOR/mTOR, p-ULK1(Ser757), p-P70S6K and p-4EBP1 expressions. Additionally, DIO improved mitochondrial dynamics mainly through inhibiting the relocation of DRP1 on mitochondria and enhancing MFN1 and MFN2 expressions. In conclusion, our study demonstrated for the first time that DIO protected against kidney injury induced by 3-MCPD through the induction of autophagy via LKB1-AMPK-mTOR pathway and the improvement of mitochondrial fission and fusion.

Urinary non-targeted toxicokinetics and metabolic fingerprinting of exposure to 3-monochloropropane-1,2-diol and glycidol from refined edible oils.

The widespread presence of 3-monochloropropane-1,2-diol (3-MCPD) and glycidol in refined edible oils have raised food industrial and public health concerns, but their specific biomarkers of exposure and urinary metabolic pathways indicating nephrotoxicity remain largely unknown. Here, we unraveled the in vivo biotransformation of these two contaminants and revealed how they affect metabolic pathways in rats. Urine metabolomes in rats administered with glycidol or 3-MCPD were investigated using ultra-high performance liquid chromatography combined with a quadrupole-orbitrap high-resolution mass spectrometry. Compared to the currently acknowledged metabolite which is only 2,3-dihydroxypropyl mercapturic acid, we identified 8 and 4 new specific exposure biomarkers of glycidol and 3-MCPD, respectively, via mapping the glyceryl polymerization and glutathione and sulfur conjugation. The changes of metabolites in the surrounding metabolic network were investigated to further gain insight into their metabolic fates. Exposure to glycidol up-regulated citrate, isocitrate, ketoglutarate, malate, and pyruvate in the tricarboxylic acid cycle and glycolysis pathways, while 3-MCPD intake down-regulated these signal molecules in both pathways. Nonetheless, L-cysteine, proline, and arginine were significantly decreased by the effect of either glycidol or 3-MCPD. Our findings first map the urinary metabolomics of both contaminants from edible oils and advance the omics-level recognition for their observational health hazards.

3-Monochloropropane-1,2-diol causes spermatogenesis failure in male rats via Sertoli cell dysfunction but not testosterone reduction.

3-Monochloropane-1,2-diol (3-MCPD), a common food contaminant, has been confirmed to impair male fertility, but the mechanism has not been fully clarified. This study systematically explored the spermatogenesis impairment induced by 3-MCPD in vivo and in vitro with a focus on Sertoli cells (SCs) and spermatogonial stem cells (SSCs). After adult male Sprague-Dawley rats were administered 36 and 72 mg/kg b.w./day 3-MCPD daily for 4 weeks, the total sperm concentration dramatically decreased by 28.9 % and 57.7 %, respectively, and obvious testicular seminiferous tubule atrophy was observed. 3-MPCD exposure decreased serum testosterone levels but not intratesticular testosterone levels and upregulated the expression of steroidogenesis enzymes in both rat testes and primary Leydig cells. 3-MCPD did not reduce the number and self-renewal marker PLZF+ of SSCs; however, it downregulated the key meiotic genes Stra8 and Rec8 in the rat testis but not in primary germ cells. Although SC counts were not affected, 3-MCPD downregulated androgen receptor (AR) in rat testes and primary SCs. In addition, 3-MCPD downregulated p-CREB (transcription factor of AR), paracrine meiosis regulators Nrg1 and Nrg3 and retinoic acid synthetase Aldh1a1 in primary SCs. In summary, 3-MCPD caused impairment of spermatogenesis by inhibiting secretion of meiosis regulators and disturbing testosterone signalling in SCs.

Diallyl disulfide prevents 1,3-dichloro-2-propanol-induced hepatotoxicity through mitogen-activated protein kinases signaling.

We investigated whether diallyl disulfide (DADS) has protective effects against 1,3-dichloro-2-propanol (1,3-DCP)-induced hepatotoxicity and oxidative damage in rats and HepG2 cells. DADS was administered to rats once daily for 7 days at doses of 30 and 60 mg/kg/day. One hour after the final DADS treatment, the rats were administered 90 mg/kg 1,3-DCP to induce acute hepatotoxicity. DADS treatment significantly suppressed the increase in serum aminotransferase levels induced by 1,3-DCP administration, and reduced histopathological alterations in the liver. DADS treatment reduced 1-3-DCP-induced apoptotic changes in the liver, as revealed by terminal deoxynucleotidyl transferase dUTP nick end labeling staining and immunohistochemistry for caspase-3. DADS treatment competitively inhibited or reduced cytochrome p450 2E1 (CYP2E1) expression, which is involved in the metabolic activation of 1,3-DCP, and enhanced antioxidant properties. Furthermore, DADS treatment inhibited phosphorylation of mitogen-activated protein kinases (MAPKs) and apoptotic signaling. In in vitro experiments, MAPKs inhibitors reduced the expression of Bax/Bcl-2/Caspase 3 signaling, which effects were more significant in co-treated cells with DADS and MAPKs inhibitors. In conclusion, the protective effect of DADS against 1,3-DCP-induced hepatotoxicity may be related to blocking the metabolic activation of 1,3-DCP by suppressing CYP2E1 expression, inducing antioxidant enzyme activity, and reducing apoptotic activity by inhibiting phosphorylation of MAPKs.

Dysregulation of NrF2 expression mediates testicular injury and infertility in 3-monochloro-1,2-propandiol-intoxicated rats with special reference to accessory gland-related pathology.

3-Monochloropropane-1,2-diol (3-MCPD) is a food contaminant formed during acid hydrolysis of vegetable proteins. The toxicological evaluation of smaller doses of 3-MCPD is essential for safety evaluation of this compound. The present study investigates the toxicologic potential of 3-MCPD on male genital organs of rats, applies a correlation between the induced infertility and developed lesions in testes, epididymis, and accessory glands and study the possible mechanisms of 3-MCPD-induced male infertility. Forty rats were randomly divided into four main groups of ten animals each: the control untreated group and three treated groups that were orally administered 3-MCPD at different doses (3, 7.5 and 15 mg/kg b.w) daily via stomach intubation for five successive days per week. Five rats from each group were euthanized after 30 days. The remaining rats were euthanized after 90 days to establish subacute and chronic toxicity studies. Oxidative stress markers, Nrf2 gene expression, semen analysis, and histopathological examination were performed at the end of each experimental period. Results indicated that 3-MCPD induces infertility in male rat via disruption of Nrf2 expression in the testicular tissue with subsequent increased oxidative stress indicators in the testis that affect spermatogenesis and induced testicular degeneration, in addition, induction of epididymal lesions that affect sperm motility and concentration and finally possible development of hyperplastic tissue reactions in accessory glands of intoxicated rats predicting the carcinogenic potential of this compound.

Nephrotoxicity evaluation of 3-monochloropropane-1,2-diol exposure in Sprague-Dawley rats using data-independent acquisition-based quantitative proteomics analysis.

3-Monochloropropane-1,2-diol (3-MCPD), as a heat-induced food process contaminant, possesses strongly toxic effect on kidney. The present study focuses on characterizing the proteome and clarifying the underlying molecular regulatory mechanisms in a model of kidney injury in rats treated with 3-MCPD. Data-independent acquisition (DIA)-mass spectrometry (MS) based proteomics was used to identify dysregulated proteins in kidney tissues of Sprague-Dawley (SD) rats treated with 30 mg/kg/day 3-MCPD by gavage for 28 days. It was found that a total of 975 proteins were deregulated after 3-MCPD treatment. Bioinformatic analyses revealed that several enzymes related to the metabolisms of amino acid, lipid and carbohydrate in endogenous metabolism were altered in response to 3-MCPD treatment. Moreover, some proteins involved in these pathways were also changed, mainly including oxidative stress, oxidative phosphorylation, apoptosis and autophagy. Our study unravels the vital roles of loss of mitochondrial homeostasis and function and cell death pathways in the development of renal damage induced by 3-MCPD, which provides further valuable insights into the initiation and resolution of 3-MCPD nephrotoxicity. The proposed DIA-MS workflow not only provides a choice for proteomic analysis in toxicological research, but also provides a more comprehensive understanding of the molecular mechanisms of nephrotoxicity induced by toxins.

Ginsenoside Rb1 alleviates liver injury induced by 3-chloro-1,2-propanediol by stimulating autophagic flux.

In recent years, foodborne pollutants have become a hot issue in the field of food safety. 3-chloro-1,2-propanediol (3-MCPD) is a widely existing food contaminant. In our previous study, it was confirmed that 3-MCPD can block autophagic flux by inhibiting lysosomal function, thus causing liver injury. Ginseng is a traditional Chinese herbal medicine that contains a variety of bioactive ingredients, among which ginsenoside Rb1 (Gs-Rb1) is the most abundant. In this study, we aim to use Gs-Rb1 to improve 3-MCPD-induced autophagic flux blockage to alleviate liver injury. First, a nontoxic dose of Gs-Rb1 was identified by screening with the MTT method in which Gs-Rb1was added to HepG2 cells and co-treated with 3-MCPD. We found that Gs-Rb1 effectively enhanced the cell activity inhibited by 3-MCPD. Meanwhile, apoptosis data showed that Gs-Rb1 significantly alleviated the apoptosis of HepG2 cells induced by 3-MCPD. Subsequently, we found that Gs-Rb1 could alleviate autophagic flux blockage caused by 3-MCPD in a dose-dependent manner by detecting autophagy-related protein levels and transfecting mRFP-GFP-LC3 adenovirus. On this basis, we used Western blotting and qPCR to explore whether miR-128 was involved in the alleviation effect of Gs-Rb1 on autophagic flux blockade induced by 3-MCPD. The results showed that Gs-Rb1 inhibited the expression of miR-128 and promoted the nuclear expression and target gene transcription of TFEB. Finally, the findings were confirmed by using a hsa-miR-128 inhibitor and mimic. We found that hsa-miR-128 inhibitor alleviated the autophagic flux blockage and apoptosis caused by 3-MCPD and Gs-Rb1 also had a certain alleviation effect on the autophagic flux blockage and apoptosis caused by hsa-miR-128 mimic. This study elaborated the mechanism by which Gs-Rb1 alleviates hepatotoxicity induced by foodborne 3-MCPD by stimulating autophagic flux via miR-128-targeted TFEB, which provides a reliable theoretical basis and target for the use of natural substances to reduce the harm of food processing pollutants on the human body. PRACTICAL APPLICATION: We found that natural ginsenoside Rb1 can alleviate liver injury induced by 3-MCPD(a toxic substance found in foods such as refined vegetable oil, soy sauce, and baby milk powder), which is conducive to the development and utilization of ginseng and has practical significance for the prevention of foodborne liver injury.

Quantification and cytotoxicity of degradation products (chloropropanols) in sucralose containing e-liquids with propylene glycol and glycerol as base.

Electronic cigarettes (e-cigarettes) have gained increasing popularity in recent years, mostly because they are supposed to be less harmful than regular cigarettes. Therefore, it is highly imperative to investigate possible noxious effects to protect the consumers. E-liquids consist of propylene glycol, glycerol, aroma compounds and sweeteners. One of these sweeteners is a chlorinated version of sucrose, namely sucralose. The aim of this work was to investigate degradation products of sucralose in the presence of propylene glycol and glycerol at different temperatures of commercially available e-cigarettes. Chemical analysis and biological tests were simultaneously performed on e-liquid aerosol condensates. The results of the chemical analysis, which was executed by employing GC-MS/GC-FID, demonstrated high amounts of various chloropropanols. The most abundant one is extremely toxic, namely 3-chloropropane-1,2-diol, which can be detected at concentrations ranging up to 10,000 mg/kg. Furthermore, a cytotoxicity investigation of the condensates was performed on HUVEC/Tert2 cells in which metabolic activity was determined by means of resazurin assay. The cellular metabolic activity significantly decreased by treatment with e-liquid aerosol condensate. Due to the results of this study, we advise against the use of sucralose as sweetener in e-liquids.

Apoptosis is induced by sub-acute exposure to 3-MCPD and glycidol on Wistar Albino rat brain cells.

3-chloropropane-1,2-diol (3-MCPD) and its toxic metabolite glycidol were classified by the International Agency for Research on Cancer (IARC) as belonging to group 2B and 2A for humans. This study aimed to determine the sub-acute toxicity of these agents. Rats were exposed to 3-MCPD at 0.87 and 10 mg/kg/bw and glycidol (2,4 and 37,5 mg/kg/bw) for 90 days. miR-21 gene expression levels significantly decreased in all group's cerebellar tissues compared with control. Exposure to 10 mg/kg/bw 3-MCPD showed significant increases in PTEN in brain as compared to control group. The Akt gen expressions were significantly decreased in 3-MCPD and glycidol groups when compared to control group brains. Additionally, Caspase 3 and AIF immunopositivity significantly increased in 3-MCPD high dose and glycidol high dose groups in cerebellum granular layers compared to control. The results of the present study conclude that 3-MCPD and glycidol can induce apoptosis in rat brain tissue.

In vivo mutagenicity and tumor-promoting activity of 1,3-dichloro-2-propanol in the liver and kidneys of gpt delta rats.

1,3-Dichloro-2-propanol (1,3-DCP), a food contaminant, exerts carcinogenic effects in multiple organs, including the liver and kidneys, in rats. However, the underlying mechanisms of 1,3-DCP-induced carcinogenesis remain unclear. Here, the in vivo mutagenicity and tumor-promoting activity of 1,3-DCP in the liver and kidneys were evaluated using medium-term gpt delta rat models previously established in our laboratory (GPG and GNP models). Six-week-old male F344 gpt delta rats were treated with 0 or 50 mg/kg body weight/day 1,3-DCP by gavage for 4 weeks. After 2 weeks of cessation, partial hepatectomy or unilateral nephrectomy was performed to collect samples for in vivo mutation assays, followed by single administration of diethylnitrosamine (DEN) for tumor initiation. One week after DEN injection, 1,3-DCP treatment was resumed, and tumor-promoting activity was evaluated in the residual liver or kidneys by histopathological analysis of preneoplastic lesions. gpt mutant frequencies increased in excised liver and kidney tissues following 1,3-DCP treatment. 1,3-DCP did not affect the development of glutathione S-transferase placental form-positive foci in residual liver tissues, but enhanced atypical tubule hyperplasia in residual kidney tissues. Detailed histopathological analyses revealed glomerular injury and increased cell proliferation of renal tubular cells in residual kidney tissues of rats treated with 1,3-DCP. These results suggested possible involvement of genotoxic mechanisms in 1,3-DCP-induced carcinogenesis in the liver and kidneys. In addition, we found that 1,3-DCP exhibited limited tumor-promoting activity in the liver, but enhanced clonal expansion in renal carcinogenesis via proliferation of renal tubular cells following glomerular injury.

Diosgenin Protects Against Kidney Injury and Mitochondrial Apoptosis Induced by 3-MCPD Through the Regulation of ER Stress, Ca2+ Homeostasis, and Bcl2 Expression.

SCOPE: Diosgenin (DIO) is a natural steroid sapogenin presented in various plants. It exerts anti-oxidant, anti-inflammatory and anti-diabetic nephropathy properties. The present study evaluates the intervention effect of DIO on nephrotoxicity induced by food contaminant 3-chloro-1, 2-propanediol (3-MCPD) in vivo and in vitro. METHODS AND RESULTS: Treatment with DIO (15 mg kg-1 d-1 ) in Sprague-Dawley rats for 4-week relieves kidney injury induced by 3-MCPD (30 mg kg-1 d-1 ). In vitro, DIO (2, 6, and 8 µM) alleviates cell injury and apoptosis effectively in human embryonic kidney (HEK293) cells. DIO realizes its protective function via the regulation of endoplasmic reticulum (ER) stress and mitochondrial apoptosis pathway. Blockage of ER stress by 4-phenylbutyric acid (4-PBA), a specific ER stress antagonist, inhibits mitochondrial apoptosis, suggesting a connection between mitochondrial apoptosis and ER stress. Furthermore, the study demonstrates that the maintenance of Ca2+ homeostasis and Bcl2 expression, two main targets of ER stress, contributes to the protection role of DIO on mitochondrial-dependent apoptosis. In addition, DIO relieves the impairment of oxidative phosphorylation. CONCLUSION: This study demonstrates that DIO exerts protective effect against kidney injury, mitochondrial dysfunction, and apoptosis through the inhibition of ER stress and the further maintenance of Ca2+ homeostasis and Bcl2 expression.

Proteomic Analyses of 3-Monochloropropanediol 1-Monooleate and 1-Monostearate Induced Testicular Toxicity in a 90 Day Sprague-Dawley Rats' Study.

3-Monochloropropane 1,2-diol (3-MCPD) esters are toxicants formed during food thermal processing, and their testicular toxicities were widely reported. In this 90 day in vivo study, Sprague-Dawley rats were treated with 3-MCPD 1-monooleate at 10 and 100 mg/kg body weight (bw)/day or 1-monostearate at 15 and 150 mg/kg bw/day. Histological results indicated that testicular impairment was observed, and the level of serum testosterone was decreased dose dependently, while the levels of serum transforming growth factor beta and interferon-γ in rats' serum were increased dose dependently. To address the molecular mechanisms leading to testicular toxicities of 3-MCPD esters, testes samples were investigated with a mass spectrometry proteomic approach. The deregulated proteins affected by 3-MCPD esters include many enzymes related with the inflammatory necrosis pathways. While verifying the results in cellular level, 3-MCPD 1-monooleate and 3-MCPD 1-monostearate showed almost similar testicular cytotoxicity, and they could activate RIPK1 and MLKL pathways at the cellular level. All of these results showed the possible mechanisms about the toxicity of 3-MCPD esters in rats' testes and play a vital role in understanding the toxic effects of 3-MCPD esters both in vivo and in vitro.

The role of PGC-1α and metabolic signaling pathway in kidney injury following chronic administration with 3-MCPD as a food processing contaminant.

3-Monochloropropane-1,2-diol (3-MCPD) as a byproduct of food processing and a carcinogenic agent has attracted much attention in the last decades. Kidney is the main target organ that is sensitive to the toxicity of 3-MCPD. Due to limited evidence about possible 3-MCPD toxicity, we design an investigation to determine the role of mitochondrial biogenesis following chronic oral administration of 3-MCPD (2, 4, 8 and 32 mg/kg) for 2 months in male C57 mice. The present study evaluated the affects of 3-MCPD in modulating metabolic signalling which is associated with Il-18, PGC-1α, Nrf-2 and Sir3 which are the major transcription factors. Our data confirms controversial behaviors after chronic exposure with 3-MCPD. Over expression of the PGC-1α and Sir3 and IL-18 were observed after exposure with 2,4 & 8 mg kg-1  day-1 of 3-MCPD. In front, PGC-1α down-regulation occurs at the highest dose (32 mg/kg) resulted in kidney injury. Based on the findings, PGC-1α plays an important role in the restoration of the mitochondrial function during the recovery from chronic kidney injury. We suggest that the PGC-1α can be consider as a therapeutic target in prevention and treatment of kidney injury after chronic exposure of 3-MCPD. PRACTICAL APPLICATIONS: 3-Monochloropropane-1, 2-diol (3-MCPD) existed in several foods, can induce nephrotoxicity, progressive nephropathy and renal tubule dilation following acute and chronic exposure. It revealed that 3-MCPD toxicity is related to metabolites which can cause oxidative stress and activation of cell death signaling. It seems that cytotoxicity of 3-MCPD has disruptive effect on kidney cells due to rise in ROS production and decrease in mitochondrial membrane permeability. These effects can lead to MPT pore opening, cytochrome c release and activation of programed cell death signaling pathway. Therefore, present study was investigated the role of PGC-1a and the metabolic signaling involved in 3-MCPD-induced nephrotoxicity for the first time. Our data revealed that up-regulation of mitochondrial biogenesis following chronic exposure with 3-MCPD accelerates recovery of mitochondrial and cellular function in kidney by deacetylation of histones, overexpression of transcription factors (PGC-1α, Nrf-2, and Sir3) and maintaining cellular homeostasis.

1,3-dichloro-2-propanol induced lipid accumulation by blocking autophagy flux in HepG2 cells.

Great attention has been paid to 1,3-dichloro-2-propanol (1,3-DCP) due to its presence in food and concerns about toxic potential as carcinogens. In our previous study, we found that long-term low-dose 1,3-DCP exposure induced lipid accumulation in mouse liver. Recent studies have demonstrated that autophagy plays an important role in regulating lipid metabolism. So, we speculated that 1,3-DCP induced lipid accumulation by regulating autophagy in hepatocytes. In this study, we first studied the effect of 100 µM 1,3-DCP on autophagy flux in HepG2 cells. The data showed that 1,3-DCP (100 µM) impaired autophagy flux mainly through the attenuation of autophagosomes via AKT/mTOR signaling pathway and inhibition of lysosomes biosynthesis. Furthermore, we demonstrated that treatment with 100 µM 1,3-DCP for 24 h affected lipid metabolism through the colocalization of LC3 and Bodipy. We used an autophagy activator or an autophagy inhibitor to test the effect of 1,3-DCP on lipid accumulation through detecting lipid droplets staining, triglyceride (TG) and total cholesterol (TC). The data showed that 1,3-DCP-induced lipid accumulation was alleviated in the presence of Rapamycin (an autophagy activator). On the contrary, 1,3-DCP-induced lipid accumulation was significantly exacerbated in the presence of an autophagy inhibitor (3-methyladenine or chloroquine). These results suggested that 1,3-DCP might induce lipid accumulation by the impairment of autophagy flux in HepG2 cells.