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Asian Pacific Journal of Cancer... Sep 2022Cholangiocarcinoma (CCA) is a highly aggressive tumor with a greater risk of distant metastasis. The promising anti-CCA activity and safety profile of Atractylodes...
OBJECTIVES
Cholangiocarcinoma (CCA) is a highly aggressive tumor with a greater risk of distant metastasis. The promising anti-CCA activity and safety profile of Atractylodes lancea (AL) have previously been reported in a series of in vitro, in vivo and clinical studies. The present study investigated the effect of AL extract on apoptosis and metastasis signaling pathways in the Opisthorchis viverrini/dimethylnitrosamine (OV/DMN)-induced CCA hamster model.
MATERIALS AND METHODS
Hamster liver tissues were obtained from the four groups (n = 5 per group), i.e., (i) 5-FU treated CCA (40 µg/mL); (ii) CCA; (iii) AL-treated CCA (5,000 mg/kg), and (iv) normal hamsters. Total RNA was isolated, and the expression levels of apoptosis-related and metastasis-related genes were determined by qRT-PCR analysis.
RESULTS
The expression levels of p16, caspase-3, caspase-8, caspase-9, Apaf-1, p53 and Eef1a1 were downregulated, while that of the remaining genes were upregulated in CCA hamsters compared with normal hamsters. AL treatment increased the expression of p16, caspase-9, caspase-3, Apaf-1, p53 and E-cadherin and decreased the expression of cyclin D1, cdk4, Bax, Akt/PKB, Bcl-2, Mfge-8, Lass4, S100A6, TGF-β, Smad-2, Smad-3, Smad-4, MMP-9, and N-cadherin. The expression of Eef1a1 was unchanged.
CONCLUSION
The anti-CCA activity of AL in OV/DMN-induced CCA hamsters could be due to the induction of cell cycle arrest at the G1 phase and activation of the apoptosis pathway, resulting in cancer cell death. The activation of the apoptosis pathway mainly involved the intrinsic pathway (activation of caspase-3 and caspase-9 through p53 and Mfge-8 modulation and downregulation of anti-apoptotic genes Akt and Bcl-2). In addition, AL could also inhibit the canonical TGF-β signaling pathway, MMP-9 and N-cadherin to suppress tumor metastasis.
Topics: Animals; Atractylodes; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cadherins; Caspase 3; Caspase 8; Caspase 9; Cholangiocarcinoma; Cricetinae; Cyclin D1; Dimethylnitrosamine; Fluorouracil; Humans; Matrix Metalloproteinase 9; Mesocricetus; Opisthorchiasis; Opisthorchis; Plant Extracts; Proto-Oncogene Proteins c-akt; RNA; Transforming Growth Factor beta; Tumor Suppressor Protein p53; bcl-2-Associated X Protein
PubMed: 36172672
DOI: 10.31557/APJCP.2022.23.9.3093 -
Journal of Pharmaceutical and... Sep 2022The possibility of N-Nitrosation in the absence of nitrosating agents was studied on model solutions and film coated tablets containing metformin. N-nitrosodimethylamine...
The possibility of N-Nitrosation in the absence of nitrosating agents was studied on model solutions and film coated tablets containing metformin. N-nitrosodimethylamine (NDMA) and N-nitrosation precursors (dimethylamine and nitrites) were determined using previously published fully validated analytical methods. Alternative routes to N-nitrosation were found. Dimethylamine can undergo an oxidation to nitrite in the presence of strong oxidants (e.g., HO), as was observed during wastewater treatment in several published works. The resulting nitrite can consecutively act as a nitrosating agent. We proved that the described reaction indeed leads to N-nitrosation (NDMA formation in case of dimethylamine precursor) in model solutions made of dimethylamine and HO. An experiment was designed in order to prove those reactions take place in dosage forms. Film coated tablets present a highly heterogenous system with several solid phases and low water activity, which is in stark contrast to the liquid wastewater, where this reaction was originally studied. Despite that, the described reaction took place even in the tablets, but only to a small degree. The amount formed via this alternative route corresponds to less than 10 % of the total formed NDMA. The pH optimum of this alternative route lies in the alkaline range which was confirmed by the determined NDMA concentration in model solutions. The solid phase system (i.e., tablets) was found to behave differently. The addition of NaCO into the tablets during manufacture resulted in tablets without NDMA (c < LOQ) even in batches spiked with both dimethylamine and HO. Thus, adjusting the pH of the solid dosage forms remains a sufficient measure of controlling N-nitrosamines in the product, even in product with limit amounts of oxidating agent (HO) and N-nitrosation precursor (dimethylamine).
Topics: Dimethylamines; Dimethylnitrosamine; Hydrogen Peroxide; Nitrites; Nitrosation; Pharmaceutical Preparations
PubMed: 35696937
DOI: 10.1016/j.jpba.2022.114872 -
Journal of Pharmaceutical and... Feb 2021An effective analytical method for the quantification of N-nitrosodimethylamine (NDMA) using a liquid chromatography coupled with tandem mass spectrometry was developed...
An effective analytical method for the quantification of N-nitrosodimethylamine (NDMA) using a liquid chromatography coupled with tandem mass spectrometry was developed and applied to a process optimization study of the production of metformin film coated tablets in order to identify the key factors behind the NDMA formation in metformin products. The method uses a linear gradient elution with mobile phases 0.1 % formic acid in water for chromatography and methanol for chromatography and a column Acquity UPLC HSS T3 1.8 μm. The use of the tandem mass spectrometry in a positive ion mode with an atmospheric pressure chemical ionization allows for the use of an isotopically labelled internal standard and an external calibration standard. The method was validated according to the guidelines of International Council for Harmonization in terms of limit of detection and quantification, linearity, precision, accuracy and method selectivity. To further justify the effectiveness of the method, a comparison between two laboratories was performed using a linear regression testing. Both methods give comparable results. 469 samples of both metformin active pharmaceutical ingredient and film coated tablets were analysed and the key factors behind NDMA formation were identified. Hypotheses explaining the mechanism were formulated and confronted with measurements and scientific literature. Protective measures to prevent NDMA contamination in metformin products were drawn.
Topics: Chromatography, High Pressure Liquid; Chromatography, Liquid; Dimethylnitrosamine; Drug Contamination; Metformin; Reproducibility of Results; Tandem Mass Spectrometry
PubMed: 33422831
DOI: 10.1016/j.jpba.2020.113877 -
Journal of Pharmaceutical and... Feb 2022N-Nitrosodimethylamine (NDMA) has been detected in some drug substances and pharmaceutical products containing sartans, ranitidine and metformin, and a potential risk of...
N-Nitrosodimethylamine (NDMA) has been detected in some drug substances and pharmaceutical products containing sartans, ranitidine and metformin, and a potential risk of NDMA contamination exists in other drug substances and their pharmaceutical products. To quantitate NDMA in various drugs having diverse physicochemical properties, a specific, sensitive, and reliable analytical method is required, in addition to methods that can be applied to a class of nitrosamines. We aimed to develop an off-line isolation method for NDMA in drug substances using SPE for quantification with LC-APCI-MS/MS. Impediments to accurate quantitation of NDMA in drug substances using LC-MS/MS and insufficient durability of the system are attributed to the extremely large amounts of active pharmaceutical ingredients (APIs) in sample solutions in comparison to the trace amount of NDMA. A reduced retention of NDMA and/or decreased separation from other substances in LC, matrix effect in MS detection, and undesirable contamination of instruments with API and other substances may be occasionally encountered, all of which consequently result in deterioration of system performance and generation of unreliable data, even in the cases where a divert valve is configured between the column and ion source of the MS instrument. To address these problems, an off-line NDMA isolation methodology from APIs exhibiting diverse physicochemical properties, namely ranitidine hydrochloride (ranitidine), metformin hydrochloride (metformin), nizatidine, valsartan, and telmisartan, was developed. The applicability of the method was confirmed by batch analysis of metformin and ranitidine. Furthermore, contrary to previous reports, NDMA was found to be stable over a wide pH range. The proposed methodology and data from this study would contribute to the control of NDMA contamination in various drugs to realize the safe delivery of pharmaceuticals to patients.
Topics: Chromatography, Liquid; Dimethylnitrosamine; Gas Chromatography-Mass Spectrometry; Humans; Pharmaceutical Preparations; Solid Phase Extraction; Tandem Mass Spectrometry
PubMed: 34974238
DOI: 10.1016/j.jpba.2021.114561 -
Journal of Pharmaceutical and... Sep 2020N-Nitrosodimethylamine (NDMA) has been detected in some drug substance and drug products containing sartans, ranitidine and metformin. N-nitrosodiethylamine (NDEA) has...
Determination of N-nitrosodimethylamine and N-nitrosomethylethylamine in drug substances and products of sartans, metformin and ranitidine by precipitation and solid phase extraction and gas chromatography-tandem mass spectrometry.
N-Nitrosodimethylamine (NDMA) has been detected in some drug substance and drug products containing sartans, ranitidine and metformin. N-nitrosodiethylamine (NDEA) has also been found to be present in some sartan medications. A method for the simultaneous detection of NDMA and NDEA in drug substances and finished products of sartans, metformin and ranitidine has been optimized using isotope dilution, clean-up procedure and gas chromatography-tandem mass spectrometry (GC-MS/MS). The purification of drug substances and excipients was efficient when utilizing precipitation and activated charcoal cartridges. Most of irbesartan, pimasartan, olmesartan, and candesartan were removed by precipitation using solubility difference, while valsartan, rosartan, metformin and ranitidine were completely removed after activated charcoal purification. Even when the extracts were injected in GC-MS/MS more than 100 times, the peak shape and sensitivity did not change, and no peak interference occurred. When a 0.10 g sample was used, the range of the lower limit of detection was 0.07-0.3 μg/kg, and the range of the lower limit of quantification was 0.3-0.9 μg/kg. The precision was in the range of 0.4-2.7 % for NDMA and 0.4-4.2 % for NDEA, and the accuracy was in the range of 95.0-105 % for NDMA and 93.6-104 % for NDEA. NDMA was detected with a concentration of 0.004 mg/kg in a valsartan and 0.012 mg/kg in a ranitidine, and NDEA was detected at concentrations of 0.009 and 0.008 mg/kg in irbesartan and rosartan. Otherwise, NDMA was detected at a concentration of 0.062 mg/kg in a fimasartan product and 0.009 mg/kg in a ranitidine product. This method is available for all drug substances and finished products of sartans; metformin and ranitidine.
Topics: Angiotensin II Type 1 Receptor Blockers; Dimethylnitrosamine; Gas Chromatography-Mass Spectrometry; Metformin; Pharmaceutical Preparations; Ranitidine; Solid Phase Extraction; Tandem Mass Spectrometry
PubMed: 32663759
DOI: 10.1016/j.jpba.2020.113460 -
Chemosphere May 2023Anion exchange resin is responsible for removing harmful anionic contaminants in drinking water treatment, but it may become a significant source of precursors for...
Anion exchange resin is responsible for removing harmful anionic contaminants in drinking water treatment, but it may become a significant source of precursors for disinfection byproducts (DBPs) by shedding material during application without proper pretreatment. Batch contact experiments were performed to investigate the dissolution of magnetic anion exchange resins and their contribution to organics and DBPs. Dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) released from the resin were highly correlated with the dissolution conditions (contact time and pH), in which 0.7 mg/L DOC and 0.18 mg/L DON were distributed at exposure time of 2 h and pH 7. The formation potential of four DBPs in the shedding fraction was also revealed that trichloromethane (TCM), dichloroacetonitrile (DCAN), nitrosodimethylamine (NDMA), and dichloroacetamide (DCAcAm) concentrations could reach 21.4, 5.1, 12.1 μg/L, and 69.6 ng/L, respectively. Furthermore, the hydrophobic DOC that preferred to detach from the resin mainly originated from the residues of crosslinkers (divinylbenzene) and porogenic agents (straight-chain alkanes) detected by LC-OCD and GC-MS. Nevertheless, pre-cleaning inhibited the leaching of the resin, among which acid-base and ethanol treatments significantly lowered the concentration of leached organics, and formation potential of DBPs (TCM, DCAN, and DCAcAm) below 5 μg/L and NDMA dropped to 10 ng/L.
Topics: Anion Exchange Resins; Water Purification; Dissolved Organic Matter; Chloroform; Dimethylnitrosamine; Hydrogen-Ion Concentration; Microscopy, Electron, Scanning; Chemistry Techniques, Analytical
PubMed: 36868424
DOI: 10.1016/j.chemosphere.2023.138285 -
Helicobacter Aug 2021Helicobacter pylori (HP) has been detected in the hepatobiliary tract of cholangiocarcinoma (CCA) patients in regions both endemic and non-endemic for Opisthorchis...
BACKGROUND
Helicobacter pylori (HP) has been detected in the hepatobiliary tract of cholangiocarcinoma (CCA) patients in regions both endemic and non-endemic for Opisthorchis viverrini (OV) infection. However, whether H. pylori infection promotes CCA development remains unknown. We investigated CCA development in hamsters induced by a combination of infection with H. pylori and administration of N-nitrosodimethylamine (NDMA) and compared findings with those in an OV plus NDMA group.
MATERIALS AND METHODS
Eighty-five hamsters were divided into four groups: (1) normal, (2) administered NDMA, (3) infected with cagA H. pylori and administered NDMA (HN group), and (4) infected with OV and administered NDMA (ON group). Animals were euthanized at 3 and 6 months post-infection. Histopathological changes of liver and the expression of markers associated with carcinogenesis were studied.
RESULTS
At 3 months post-infection (p.i.), cholangitis and lymphoid follicles without tumor appearance were noted in the HN group, whereas extensive fibrosis was seen in members of the ON group, 10% of which had developed tumors. At 6 months p.i., 10% of hamsters administered NDMA alone had developed CCA, whereas in the HN and ON groups, 20% and 60% of hamsters, respectively, had developed CCA. Cytokeratin-19 (CK19) expression was observed in the CCA tissues of both the HN and the ON groups, confirming the bile duct origin of the CCA cells. CCA development in the HN group might be inflammation-mediated, as suggested by overexpression of HMGB1, PCNA, IL-8, and 8-OxodG in CCA tissues.
CONCLUSION
cagA H. pylori infection and carcinogen intake can induce CCA development with slow progression.
Topics: Animals; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cholangiocarcinoma; Cricetinae; Dimethylnitrosamine; Helicobacter Infections; Helicobacter pylori; Mesocricetus; Opisthorchis
PubMed: 34031944
DOI: 10.1111/hel.12817 -
Chemosphere Oct 2022N-Nitrosodimethylamine (NDMA) is a commonly identified carcinogenic and genotoxic pollutant in water. In this study, we prepared Ru catalysts supported on carbon...
N-Nitrosodimethylamine (NDMA) is a commonly identified carcinogenic and genotoxic pollutant in water. In this study, we prepared Ru catalysts supported on carbon nanotube (Ru/CNT) and studied the electrocatalytic reduction of N-nitrosamines on Ru/CNT electrode in a three-electrode system. The results show that Ru-based catalyst exhibits a high activity of 793.3 μmol L gCat h for electrochemical reduction of NDMA. Reaction mechanism study discloses that the electrocatalytic reduction of NDMA is accomplished by both direct electron reduction and atomic H* mediated indirect reduction pathways. Further product analysis indicates that NDMA is finally reduced to dimethylamine (DMA) and ammonia. The reduction efficiency of NDMA strongly relies on cathode potential, initial NDMA concentration and solution pH. To verify the universality of Ru/CNT electrode, electrocatalytic reduction of three dialkyl N-nitrosamines with different alkyl groups was performed and Ru catalyst has high catalytic activities for the three N-nitrosamines, while the catalytic efficiency differs with their structures. Simultaneous electrochemical reduction of the three N-nitrosamines indicates that the reduction rates of N-nitrosamines follow the same order in the multiple-component system as that in the single-component system. Catalyst recycling results demonstrate that after 5 consecutive recycling runs Ru/CNT electrode remains almost identical catalytic activity to the fresh catalyst, manifesting the high catalytic stability of Ru/CNT electrode.
Topics: Catalysis; Dimethylnitrosamine; Nitrosamines; Oxidation-Reduction; Water Purification
PubMed: 35728667
DOI: 10.1016/j.chemosphere.2022.135414 -
International Journal of Environmental... Sep 2021Many nitrosamines are potent carcinogens, with more than 30 listed under California's Proposition 65. Recently, nitrosamine contamination of commonly used drugs for...
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--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.
Topics: Animals; Carcinogens; Diabetes Mellitus, Type 2; Diethylnitrosamine; Dimethylnitrosamine; Neoplasms; Nitrosamines
PubMed: 34574388
DOI: 10.3390/ijerph18189465 -
Cancer Epidemiology, Biomarkers &... Dec 2021The discovery that ranitidine is contaminated with -nitrosodimethylamine, a suspected human carcinogen, raises the hypothesis of a gastrointestinal carcinogenic effect;...
BACKGROUND
The discovery that ranitidine is contaminated with -nitrosodimethylamine, a suspected human carcinogen, raises the hypothesis of a gastrointestinal carcinogenic effect; however, evidence remains inconclusive.
METHODS
We used the nationwide Danish Prescription Registry to identify a cohort of incident ranitidine users and two active comparator cohorts comprising users of other histamine-2 receptor blockers (H2RB) and users of proton pump inhibitors (PPI). All Danish adults with a first prescription of ranitidine, other H2RBs, or PPIs in 1996 through 2008 were followed virtually completely through 2018 for incidence of esophageal, stomach, liver, and pancreatic cancers. We used Cox regression with propensity-score weighting to calculate hazard ratios and 10-year cumulative risk with 95% confidence intervals.
RESULTS
We ascertained 276 newly diagnosed esophageal, 342 stomach, 133 hepatocellular, and 517 pancreatic cancers among ranitidine users during follow-up (median 14 years). In comparison with use of other H2RBs or PPIs, we found no consistent evidence of increased HRs or excess 10-year cumulative risk of any upper gastrointestinal cancer following ranitidine use. We observed no association after restriction to subjects with at least 5 or 10 prescriptions or those with 10 prescriptions and at least 10 years of follow-up.
CONCLUSIONS
Our large prospective study using high-quality prescription and cancer incidence data, with two active comparator groups, provides no compelling evidence that ranitidine increases the risk of upper gastrointestinal cancers.
IMPACT
Our results, which do not support any carcinogenic effect on esophagus, stomach, liver or pancreas, should be reassuring for millions of concerned past users of ranitidine.
Topics: Adult; Case-Control Studies; Denmark; Dimethylnitrosamine; Female; Gastrointestinal Neoplasms; Histamine H2 Antagonists; Humans; Male; Middle Aged; Proportional Hazards Models; Prospective Studies; Ranitidine; Registries
PubMed: 34620629
DOI: 10.1158/1055-9965.EPI-21-0831