The food additive sulfite is mixed with saliva, which contains nitrite, in the oral cavity, and the mixture is mixed with gastric juice in the stomach. In the stomach, salivary nitrite can be transformed to nitric oxide (NO). In this study, the effects of sulfite on nitrite-dependent NO production were investigated using acidified saliva (pH 2.6) and acidic buffer solutions (pH 2.0). Sulfite enhanced NO production in acidified saliva and acidic buffer solutions, and the enhancement increased with the increase in sulfite concentration from 0 to 0.1 mM, whereas suppressed NO production and the suppression increased as the concentration was increased over 0.2 mM. The enhancement was due to the increase in reaction rate between nitrous acid and nitrososulfonate (ONSO(3)(-)) that was formed by the reaction of nitrous acid with hydrogen sulfite, and the suppression was due to the increase in hydrogen sulfite-dependent consumption rate of ONSO(3)(-). A salivary component SCN(-) (1 mM) enhanced and suppressed NO production induced by 1 mM nitrite when sulfite concentrations were lower and higher than 1 mM, respectively. ONSO(3)(-) formed from hydrogen sulfite and nitrosyl thiocyanate (ONSCN), which was produced by the reaction of nitrous acid with SCN(-), seemed to contribute to the enhancement and suppression. NO production induced by nitrite/ascorbic acid systems was suppressed by sulfite, and the suppressive effects were decreased by SCN(-), whereas sulfite-induced suppression of NO production in nitrite/rutin systems was increased by SCN(-). During reactions of nitrite with sulfite in the presence and absence of SCN(-), oxygen was taken up. The oxygen uptake is discussed to be due to autoxidation of NO and radical chain reactions initiated by hydrogen sulfite radicals. The results of the present study suggest that sulfite can enhance and suppress nitrite-dependent NO production. It is discussed that radicals including hydrogen sulfite radicals can be formed through the reactions of nitrite and sulfite in the stomach.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jf2049257 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
DNA Methylation Analysis by Bisulfite Pyrosequencing of Mouse Embryonic Fibroblasts with Reprogramming Enhanced by Thyroid Hormones.
Methods Mol Biol
November 2024
Nanomaterials and Nanotechnology Research Center (CINN-CSIC), El Entrego, Spain.
DNA methylation is a widely studied epigenetic mark which in mammals involves the incorporation of a methyl group to the fifth carbon of cytosines, mainly those belonging to CpG dinucleotides. It has been linked to context-dependent regulatory functions ranging from gene and repetitive DNA silencing to gene body transcriptional activity. Because of its important roles during embryonic development and cell differentiation, DNA methylation can be used to track cell reprogramming by measuring the methylation levels of pluripotency-associated factors.
View Article and Find Full Text PDFWhole-Genome Bisulfite Sequencing with a Small Amount of DNA.
Methods Mol Biol
November 2024
Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland.
Article Synopsis
- Whole-genome bisulfite sequencing (WGBS) is commonly used for analyzing DNA methylation across genomes, but the bisulfite treatment often leads to DNA degradation.
- To address this, the post-bisulfite adapter tagging (PBAT) method was developed, which adds adapters after the bisulfite treatment.
- PBAT facilitates single-cell bisulfite sequencing (scBS-seq), allowing researchers to study DNA methylation with minimal DNA from just a few cells, making the process efficient and sensitive.
Whole Genome Methylation Sequencing via Enzymatic Conversion (EM-seq): Protocol, Data Processing, and Analysis.
Methods Mol Biol
November 2024
Bioinformatics Group, Babraham Institute, Cambridge, UK.
Article Synopsis
- Whole genome bisulfite sequencing (WGBS) has been the main method for analyzing DNA methylation but has issues with technical biases that can lead to inaccurate results, especially in cytosine-rich areas.
- A new technique called EM-seq is emerging to replace WGBS, using a two-step enzymatic conversion process that avoids the damaging effects of bisulfite conversion.
- EM-seq offers advantages like being degradation-free, requiring less DNA, achieving higher yields, ensuring less variation, and providing accurate and uniform results across a wider range of methylation sites.
Robust Bisulfite-Free Single-Molecule Real-Time Sequencing of Methyldeoxycytidine Based on a Novel hpTet3 Enzyme.
Angew Chem Int Ed Engl
December 2024
Center for Nucleic Acid Therapies at the Department of Chemistry, Institute for Chemical Epigenetics, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377, München, Germany.
In addition to the four canonical nucleosides dA, dG, dC and T, genomic DNA contains the additional base 5-methyldeoxycytidine (mdC). The presence of this methylated cytidine nucleoside in promoter regions or gene bodies significantly affects the transcriptional activity of the corresponding gene. Consequently, the methylation patterns of genes are crucial for either silencing or activating genes.
View Article and Find Full Text PDFComprehensive evaluation of the impact of whole-genome bisulfite sequencing (WGBS) on the fragmentomic characteristics of plasma cell-free DNA.
Clin Chim Acta
January 2025
BGI Research, Shenzhen 518083, China. Electronic address:
Background: Cell-free DNA (cfDNA) is non-randomly fragmented in human body fluids. Analyzing such fragmentation patterns of cfDNA holds great promise for liquid biopsy. Whole-genome bisulfite sequencing (WGBS) is widely used for cfDNA methylation profiling.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!