Search Results (15)

Mint3 enhances aerobic ATP production with subsequent nuclear translocation of hypoxia-inducible factor-1 (HIF-1) and activation of angiogenesis-related genes. It remains unclear if and when Mint3 is activated and whether it is involved in hepatocarcinogenesis. We explored the expression of Mint3 in surgically resected hepatocellular carcinoma (HCC) tissues. We evaluated the effects of Mint3 knockdown on spheroid formation capacity and subcutaneous tumor growth in immune-deficient mice. We used Mint3 knockout mice to evaluate the effects of chemically induced HCC development. Mint3 was overexpressed in well-differentiated HCC with the activation of HIF-1 target genes irrespective of the absence of hypervascularization. Mint3 knockdown ameliorated the expression of HIF-1 target genes in patient-derived HCC cell lines and suppressed spheroid formation. Mint3 knockdown further inhibited subcutaneous tumor formation in vivo in immune-deficient mice. Chemical HCC development induced by N-nitrosodiethylamine (DEN) or DEN/CCl4 was dramatically suppressed in Mint3 knockout mice compared to control mice. Mint3 plays a crucial role in early-stage HCC development before hypervascularization by activating HIF-1 target genes before the tumor becomes hypoxic. Mint3 is a molecular target that prevents HCC development in the early stages. Full article

This study investigated the effect of using celery powder (CP) as source of pre-converted nitrite (treatments: A: 150 mg/kg NaNO₂, B: 100 mg/kg NaNO₂ + CP as 50 mg/kg NaNO₂ equivalent, C: 50 mg/kg NaNO₂ + CP as 100 mg/kg NaNO₂ equivalent, D: CP as 150 mg/kg NaNO₂ equivalent) on the physicochemical and microbiological properties in heat-treated sucuk (HTS), a kind of semi-dry fermented sausage. The influence of cooking time (CT) on the nitrosamine formation in HTS with and without CP was also determined. The results indicated that the use of CP increased the pH value and decreased the a_w value. Micrococcus/Staphylococcus and residual nitrite were not affected by the use of CP. TBARS value varied from 0.78 to 0.90 mg MDA/kg. CP did not affect the abundance of hexanal in HTS, however, it increased the abundance of camphene. The results of PCA showed that treatments A, B, and C had similar volatile compound profiles. CP did not affect both N-nitrosodimethylamine and N-nitrosodiethylamine, but their levels increased as the CT increased. Increased CT also resulted in increased N-nitrosopiperidine (NPIP) in all treatments, but the cooking for 1 min did not cause a significant increase in treatments A, B, and C. CP leads to a significant increase in NPIP content, especially after 3 and 5 min of cooking in HTS. Full article

N-nitrosodiethylamine (NDEA) is a potential carcinogen known to cause liver tumors and chronic inflammation, diabetes, cognitive problems, and signs like Alzheimer’s disease (AD) in animals. This compound is classified as probably carcinogenic to humans. Usual sources of exposure include food, beer, tobacco, personal care products, water, and medications. AD is characterized by cognitive decline, amyloid-β (Aβ) deposit, tau hyperphosphorylation, and cell loss. This is accompanied by neuroinflammation, which involves release of microglial cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin 1β (IL-1β), by nuclear factor kappa B (NF-κB) upregulation; each are linked to AD progression. Weak PI3K/Akt insulin-signaling inhibits IRS-1 phosphorylation, activates GSK3β and promotes tau hyperphosphorylation. Metformin, an antihyperglycemic agent, has potent anti-inflammatory efficacy. It reduces proinflammatory cytokines such as IL-6, IL-1β, and TNF-α via NF-κB inhibition. Metformin also reduces reactive oxidative species (ROS) and modulates cognitive disorders reported due to brain insulin resistance links. Our study examined how NDEA affects spatial memory in Wistar rats. We found that all NDEA doses tested impaired memory. The 80 µg/kg dose of NDEA increased levels of Aβ1-42, TNF-α, and IL-6 in the hippocampus, which correlated with memory loss. Nonetheless, treatment with 100 mg/kg of metformin attenuated the levels of pro-inflammatory cytokines and Aβ1-42, and enhanced memory. It suggests that metformin may protect against NDEA-triggered memory issues and brain inflammation. Full article

The use of solvents is overall recognized as an efficient method to improve the water permeability of polyamide thin film composite membranes (PA-TFC). The objective of this work was to test the performance of the membranes after exposing them to n-propanol (n-PrOH) to improve the permeability of the membranes while maintaining the rejection factor for small uncharged organic molecules, namely N-nitrosamines (NTRs). After the membranes were exposed to n-PrOH, the water permeability of the UTC73AC membrane increased by 98%, with minimal change in rejection. N-nitrosodiethylamine (NDEA) rejection decreased (3.4%), while N-nitrosodi-n-propylamine (NDPA) and N-nitrosodi-n-butylamine (NDBA) rejection increased by 0.9% and 2.8%, respectively. In contrast, for the BW30LE membrane, water permeability decreased (by 38.7%), while rejection factors increased by 14.5% for NDEA, 6.2% for NDPA, and 15.0% for NDBA. In addition, the morphology of the membrane surface before and after exposure to n-PrOH was analyzed. This result and the pore size distribution (PSD) curves obtained indicate that the rearrangement of polymer chains affects the network or aggregate pores in the PA layer, implying that a change in pore size or a change in pore size distribution could improve the permeability of water molecules, while the rejection factor for NTRs is not significantly affected. Full article

This study was conducted with the aim of determining the effects of different black garlic (BG) levels (1%, 2% and 3%) on quality characteristics of a semi-dry fermented sausage (heat-treated sucuk). In addition, the effect of cooking time (0, 1 or 3 min at 180 °C on a hot plate) on nitrosamine formation was investigated. Fresh garlic (FG, 1%) was evaluated as the control group. BG (2% and 3%) caused a reduction in the count of lactic acid bacteria while leading to an increase in pH. FG1% gave the highest number of Micrococcus/Staphylococcus, as well as a_w value. The thiobarbituric acid reactive substance (TBARS) value increased with increasing BG levels. FG (1%) showed the highest residual nitrite amount (p < 0.05). The scores for color, taste and general acceptability were reduced by the use of BG (p < 0.05). No significant difference was observed between the garlic treatments in terms of N-Nitrosodimethylamine (NDMA) and N-Nitrosodiethylamine (NDEA) when no additional cooking was applied. Cooking time was determined to have no significant effect on NDMA in 3% BG. The use of BG caused an increase in N-Nitrosopiperidine (NPIP) (p < 0.05). As for PCA, a closer correlation between NPIP and the groups containing BG was observed, while there was a strong correlation between NDMA and the FG group cooked for 3 min. The use of BG caused an increase in NPIP, but affected NDMA and NDEA depending on the cooking time. Full article

Hepatocellular carcinoma (HCC) is the terminal phase of multiple chronic liver diseases, and evidence supports chronic uncontrollable inflammation being one of the potential mechanisms leading to HCC formation. The dysregulation of bile acid homeostasis in the enterohepatic circulation has become a hot research issue concerning revealing the pathogenesis of the inflammatory-cancerous transformation process. We reproduced the development of HCC through an N-nitrosodiethylamine (DEN)-induced rat model in 20 weeks. We achieved the monitoring of the bile acid profile in the plasma, liver, and intestine during the evolution of “hepatitis-cirrhosis-HCC” by using an ultra-performance liquid chromatography-tandem mass spectrometer for absolute quantification of bile acids. We observed differences in the level of primary and secondary bile acids both in plasma, liver, and intestine when compared to controls, particularly a sustained reduction of intestine taurine-conjugated bile acid level. Moreover, we identified chenodeoxycholic acid, lithocholic acid, ursodeoxycholic acid, and glycolithocholic acid in plasma as biomarkers for early diagnosis of HCC. We also identified bile acid-CoA:amino acid N-acyltransferase (BAAT) by gene set enrichment analysis, which dominates the final step in the synthesis of conjugated bile acids associated with the inflammatory-cancer transformation process. In conclusion, our study provided comprehensive bile acid metabolic fingerprinting in the liver–gut axis during the inflammation-cancer transformation process, laying the foundation for providing a new perspective for the diagnosis, prevention, and treatment of HCC. Full article

In order to meet the analytical requirements of the European Medicines Agency (EMA), a new HPLC-FLD method was successfully developed using dansyl chloride for the derivatization and determination of the genotoxic impurities N-Nitrosodimethylamine (NDMA) and N-Nitrosodiethylamine (NDEA) in Lisinopril API and its final product. Samples’ pretreatment includes liquid–liquid microextraction, denitrosation, and derivatization steps. To optimize the process, the parameters contributing to high sensitivity and yielding reliable results were thoroughly studied and optimized using one-factor-at-a-time and experimental design approaches. The analytes were pre-column derivatized with Dansyl-Cl and analyzed by HPLC-fluorescence (λ_em/λ_em = 340/530) using a C₁₈ column and a mixture of phosphate buffer (pH = 2.8; 20 mM)/acetonitrile 55:45 v/v as the mobile phase. The six-level concentration calibration was shown to be linear, with R equal to 0.9995 for both analytes. The limit of detection (LOD) was satisfactory and equal to 4.7 and 0.04 ng/mL for NDMA and NDEA, respectively. Precision was less than 13.4% in all cases, and the average recoveries were equal to 109.2 and 98.1% for NDMA and NDEA, respectively. The proposed procedure is relatively easy, rapid, and suitable for the determination of the two nitrosamines in routine analysis tests. Full article

Deregulation of the DNA mismatch repair (MMR) mechanism has been linked to poor prognosis of upper aerodigestive tract cancers. Our recent in vitro data have provided evidence of crosstalk between deregulated miRNAs and MMR genes, caused by tobacco smoke (TS) N-Nitrosamines, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), in hypopharyngeal cells. Here, we explored whether chronic exposure to TS components can affect MMR mechanism and miRNA profiles in hypopharyngeal mucosa. Using a mouse model (C57Bl/6J wild type) of in vivo 14-week exposure to NNK (0.2 mmol/L) and N-Nitrosodiethylamine (NDEA; 0.004 mmol/L), with or without nicotine (0.02 μmol/L), we provide direct evidence that TS components can promote dysplasia, significant downregulation of Msh2 and Mlh1 genes and deregulation of miR-21, miR-155, miR-34a, and miR-451a. By analyzing eight human specimens from tobacco smokers and eight controls, we provide clinical evidence of a significant reduction in hMSH2 and hMLH1 mRNAs in hypopharyngeal squamous cell carcinoma (HSCC). In summary, deregulation of the MMR mechanism and miRNAs is caused by chronic exposure to TS-related N-Nitrosamines, with or without nicotine, in the early stages of upper aerodigestive tract carcinogenesis, and can also be detected in human HSCC. Thus, we encourage future studies to further elucidate a possible in vivo dose-dependent effect of individual or combined N-Nitrosamines, NNK and/or NDEA, and nicotine, on the MMR mechanism and their clinical testing to elaborate prognosis and risk assessment. Full article

N-nitrosamines have recently attracted attention as a class of disinfection byproducts and are also a hot spot in environmental studies. Current N-nitrosamine analytical methods typically involve manual solid phase extraction (SPE) of samples followed by quantitative analysis using liquid chromatography-mass spectrometry (LCMS), which is time-consuming and may also fail to eliminate complex matrix effects. Size exclusion chromatography (SEC) is a technique that can separate compounds according to their molecular size. For the first time, this study developed an Online-SPE/SEC/LCMS quantitative analysis method to detect and analyze nine common N-nitrosamine disinfection byproducts in wastewater plant tailwater, including N-dimethylnitrosamine (NDMA) and N-nitrosodiethylamine (NDEA), etc. The samples of 1.0 mL can be directly injected after the simple 0.22 μm membrane filtration. This method reports the combination of SPE, SEC, and RP C18 columns to achieve several functions in a processing time of 20 min, including online enrichment, desalination, and matrix separation for the first time. The method provides good linearity (R² > 0.999), recoveries ranging from 91.67% to 105.88%, relative standard deviation (RSD) lower than 4.17%, and the limits of detection (LOD) are 0.12–6.60 ng/L. This method alleviates tedious human labor and can effectively overcome the matrix effect (ME < 20%). This method allows for the accurate quantitative analysis of N-nitrosamines with high compatibility in wastewater plant tailwater, rivers, and lakes with a high background matrix. Interested researchers can also use this method as a reference in the online analysis of other specific pollutants after necessary optimization. It can also be utilized for non-targeted screening and targeted analysis of contaminants in water with a wide range of applications, giving valuable information for environmental monitoring. Full article

Hepatocellular carcinoma (HCC) is a common type of liver cancer and is a leading cause of death worldwide. Signal transducer and activator of transcription 3 (STAT3) is involved in HCC progression, migration, and suppression of apoptosis. This study investigates the apoptotic effect of the dietary antioxidant (n-3 PUFAs) on HepG2 cells and analyzes the underlying molecular mechanisms of this effect both in vivo and in vitro. In vivo study: Seventy-five adult male albino rats were divided into three groups (n = 25): Group I (control): 0.9% normal saline, intraperitoneal. Group II: N-Nitrosodiethylamine (200 mg/kg b.wt) intraperitoneal, followed by phenobarbital 0.05% in drinking water. Group III: as group II followed by n-3 PUFAs intubation (400 mg/kg/day). In vivo study: liver specimens for biochemical, histopathological, and immunohistochemical examination. In vitro study: MTT assay, cell morphology, PCR, Western blot, and immunohistochemical analysis. n-3 PUFAs significantly improved the histopathologic features of HCC and decreased the expression of anti-apoptotic proteins. Further, HepG2 cells proliferation was suppressed through inhibition of the STAT3 signaling pathway, cyclin D1, and Bcl-2 activity. Here we report that n-3 PUFAs may be an ideal cancer chemo-preventive candidate by targeting STAT3 signaling, which is involved in cell proliferation and apoptosis. Full article

Many nitrosamines are potent carcinogens, with more than 30 listed under California’s Proposition 65. Recently, nitrosamine contamination of commonly used drugs for treatment of hypertension, heartburn, and type 2 diabetes has prompted numerous Food and Drug Administration (FDA) recalls in the US. These contaminants include the carcinogens NDMA (N-nitrosodimethylamine) and NDEA (N-nitrosodiethylamine) and the animal tumorigen NMBA (N-nitroso-N-methyl-4-aminobutyric acid). NMBA and NDEA are metabolically and/or structurally related to NDMA, an N-nitrosomethyl-n-alkylamine (NMA), and 12 other carcinogenic NMAs. These nitrosamines exhibit common genotoxic and tumorigenic activities, with shared target tumor sites amongst chemicals and within a given laboratory animal species. We use the drug valsartan as a case study to estimate the additional cancer risks associated with NDMA and NDEA contamination, based on nitrosamine levels reported by the US FDA, cancer potencies developed by California’s Proposition 65 program and the US Environmental Protection Agency (EPA), and specific exposure scenarios. These estimates suggest that nitrosamine contamination in drugs that are used long-term can increase cancer risks and pose a serious concern to public health. Full article

A novel HPLC method with fluorimetric detection was developed for the determination of potentially carcinogenic N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) in active pharmaceutical ingredient enalapril maleate. N-nitrosamines were subject to denitrosation followed by derivatisation with dansyl chloride or fluorenylmethoxycarbonyl chloride (Fmoc-Cl). Fmoc-Cl offers much better sensitivity and repeatability than dansyl chloride derivatisation. A satisfactory linearity was obtained for the method, with R² = 0.9994 for NDMA and 0.9990 for NDEA, and a limit of quantification level of 0.038 μg/g for NDMA and 0.050 μg/g for NDEA. The precision decreased with the concentration to a maximum level of about 10%. The recoveries were in the range of 74.2 ± 4.2% to 101.6 ± 16.1% for NDMA and 90.6 ± 2.9% to 125.4 ± 7.4% for NDEA. Dansyl chloride was found to be an inappropriate derivatisation agent, mainly due to potential contamination with dimethylamine, leading to unrepeatable peaks in the blank solution. Since the method involves the derivatisation of amines liberated from the N-nitrosamines, it was necessary to remove the amines from the test sample. Several critical points in the standard/sample preparation have been mentioned, which affect the reproducibility of the method and are not covered in similar articles. Full article

N-Nitrosodiethylamine (NDEA) is a nitrosamine derivative with carcinogenic and mutagenic properties which can be found in tobacco smoke, meat and various food products. This study examined the antioxidant and hepatoprotective potential of Cajanus cajan (C. cajan) with respect to hepatotoxicity in male Wistar rats. Administration of NDEA induced hepatotoxicity at 200 mg/kg while C. cajan was administered (200, 400 and 800 mg/kg) for 28 days. NDEA-induced hepatotoxicity significantly (p ≤ 0.05) increased alanine aminotransferase (ALT), aspartate aminotransferase (AST) and malondialdehyde (MDA) and significantly (p ≤ 0.05) decreased reduced glutathione (GSH), albumin (ALB), glutathione S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD). C. cajan-treated groups were seen to have significantly (p ≤ 0.05) decreased ALT and AST and significantly (p < 0.05) increased ALB, GST, GSH, SOD and CAT. The NDEA-treated group also showed a marginal increase in body weight and a significant (p ≤ 0.05) increase in liver weight. The C. cajan treated groups showed a significant (p ≤ 0.05) increase and decrease respectively in body and liver weights. Histopathological changes also substantiated NDEA-induced hepatotoxicity and the hepatoprotective effect of C. cajan on the liver. The results indicate that C. cajan has the potential to ameliorate NDEA-induced hepatotoxicity. Full article

This study investigated the removal characteristics of N-Nitrosamines and their precursors at three pilot-scale water reclamation plants. These plants applies different integrated membrane systems: (1) microfiltration (MF)/nanofiltration (NF)/reverse osmosis (RO) membrane; (2) sand filtration/three-stage RO; and (3) ultrafiltration (UF)/NF and UF/RO. Variable removal of N-Nitrosodimethylamine (NDMA) by the RO processes could be attributed to membrane fouling and the feed water temperature. The effect of membrane fouling on N-Nitrosamine removal was extensively evaluated at one of the plants by conducting one month of operation and chemical cleaning of the RO element. Membrane fouling enhanced N-Nitrosamine removal by the pilot-scale RO process. This finding contributes to better understanding of the variable removal of NDMA by RO processes. This study also investigated the removal characteristics of N-Nitrosamine precursors. The NF and RO processes greatly reduced NDMA formation potential (FP), but the UF process had little effect. The contributions of MF, NF, and RO processes for reducing FPs of NDMA, N-Nitrosopyrrolidine and N-Nitrosodiethylamine were different, suggesting different size distributions of their precursors. Full article

The present investigation was aimed at studying the possible role of curcumin against N-nitrosodiethylamine (NDEA)-induced toxicity in albino rats. Administration of NDEA to rats at a concentration of 0.1 mg/ml in drinking water ad libitum for 21 days produced toxicity in them, which was evident from histopathological changes in the rat livers, and increased levels of blood serum enzyme markers, i.e. aspartate transaminase, alanine transaminase, alkaline phosphatase, and lactate dehydrogenase. In addition, the levels of oxidative stress markers like lipid peroxidation (LPO), protein carbonyl (PCC), and glutathione-S-transferase (GST) activity were elevated and the total glutathione (GSH) content was reduced in the livers. The administration of curcumin to rats at concentrations of 10, 20, and 40 mg/ml in drinking water along with 0.1 mg/ml of NDEA for 21 days effectively suppressed NDEA-induced toxicity and also resulted in a dose-dependent reduction in the levels of blood serum enzyme markers (AST, ALT, ALP, and LDH). Moreover, LPO, PCC, and GST activity were reduced and the GSH level was increased upon the administration of curcumin along with NDEA. The results obtained for the comet assay in rat hepatocytes and blood lymphocytes showed a significant dose-dependent decrease in the mean tail length. The micronucleus assay performed on rat hepatocytes also showed a dose-dependent reduction in the frequency of micronucleated cells along with curcumin administration. These results suggest that curcumin has a protective role against NDEA-induced toxicity in albino rats. Full article