PubMed Health⌕ Search

PubMed · 10628372

Interaction between sodium ascorbate and polyphenols.

Abstract

The interaction between sodium ascorbate and polyphenols was investigated by two different parameters: radical intensity and cytotoxicity induction. ESR spectroscopy shows that sodium ascorbate, lignins (alkali-lignin, lignin sulfonate, pine cone-derived lignin) and tannins (gallic acid, epigallocatechin gallate (EGCg), tannic acid) all produced radicals with different intensities under alkaline conditions. All lignin samples significantly enhanced the radical intensity and cytotoxic activity of sodium ascorbate, whereas all tannin samples slightly reduced the radical intensity of sodium ascorbate. Sodium ascorbate efficiently scavenged the radical and cytotoxic activity of gallic acid, as expected by the ionization potential and heat of reaction by the PM3 semiempirical method. EGCg and tannic acid slightly reduced the cytotoxic activity of sodium ascorbate. The present study demonstrates that lignins and tannins modify the radical intensity and cytotoxic activity of sodium ascorbate in different manners, and suggests the applicability of ESR spectroscopy for the screening of drug to drug interaction.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

K Satoh, Y Ida, M Ishihara, H Sakagami. Interaction between sodium ascorbate and polyphenols.. https://pubmed.ncbi.nlm.nih.gov/10628372/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Effect of light on ascorbic acid biosynthesis and bioinformatics analysis of related genes in Chinese chives.

Ascorbic acid (AsA) is an essential nutritional component and powerful antioxidant in vegetables, and in plants, AsA levels are regulated by light. AsA levels in the leaves of Chinese chive (Allium tuberosum Rottler ex Spr), a popular vegetable, are poorly understood. Thus, this study was performed to assess the influence of light on AsA biosynthesis in chive and select related genes (AtuGGP1 and AtuGME1); in addition, bioinformatic analyses and gene expression level assays were performed. The biological information obtained for AtuGGP1 and AtuGME1 was analysed with several tools, including NCBI, DNAMAN, and MEGA11. After different light treatments were performed, the Chive AsA content and AtuGGP1 and AtuGME1 expression levels were determined. These results suggest that 1) compared with natural light, continuous darkness inhibited AsA synthesis in chives. 2) The amino acid sequences of AtuGGP1 and AtuGME1 are very similar to those of other plants. 3) The trends observed for the expression levels of AtuGGP1 and AtuGME1 were consistent with the AsA content observed in chives. Hence, we speculated that light controls AsA biosynthesis in chives by regulating AtuGGP1 and AtuGME1 expression. This study provided impactful and informative evidence regarding the functions of GGP and GME in chives.

Ascorbic Acid↗

Carbon paste electrode modified with copper (II) phosphate immobilized in a polyester resin for voltammetric determination of L-ascorbic acid in pharmaceutical formulations.

A carbon paste electrode modified with copper(II) phosphate immobilized in a polyester resin (CuP-Poly) is proposed for voltammetric determination of L-ascorbic acid in pharmaceutical formulations. The modified electrode allows the detection of L-ascorbic acid at lower anodic potentials than observed at unmodified electrodes. Several parameters that can influence the voltammetric response of the proposed electrode such as carbon paste composition, pH, scan rate, and possible interference were investigated. The peak current was proportional to the concentration of ascorbic acid in the range 2.0 x 10(-5) to 3.2 x 10(-3) mol L(-1) with a detection limit of 1.0 x 10(-5) mol L(-1). The stability and repeatability of the electrode for the determination of L-ascorbic acid are also discussed. Amperometric response was also recorded for electrocatalytic oxidation of the L-ascorbic acid. Concentrations of the vitamin C in pharmaceutical formulations (tablets) measured using the modified electrode and a titrimetric method are in agreement at the 95% confidence level and within an acceptable range of error.

Ascorbic Acid↗

Immunochemical detection of hemoglobin-derived radicals formed by reaction with hydrogen peroxide: involvement of a protein-tyrosyl radical.

To investigate the involvement of a hemoglobin radical in the human oxyhemoglobin (oxyHb) or metHb/H2O2 system, we have used a new approach called "immuno-spin trapping," which combines the specificity and sensitivity of both spin trapping and antigen:antibody interactions. Previously, a novel rabbit polyclonal anti-DMPO nitrone adduct antiserum, which specifically recognizes protein radical-derived nitrone adducts, was developed and validated in our laboratory. In the present study, the formation of nitrone adducts on hemoglobin was shown to depend on the oxidation state of the iron heme, the concentrations of H2O2 and DMPO, and time as determined by enzyme-linked immunosorbent assay (ELISA) and by Western blotting. The presence of reduced glutathione or L-ascorbate significantly decreased the level of nitrone adducts on metHb in a dose-dependent manner. To confirm the ELISA results, Western blotting analysis showed that only the complete system (oxy- or metHb/DMPO/H2O2) generates epitopes recognized by the antiserum. The specific modification of tyrosine residues on metHb by iodination nearly abolished antibody binding, while the thiylation of cysteine residues caused a small but reproducible decrease in the amount of nitrone adducts. These findings strongly suggest that tyrosine residues are the site of formation of the immunochemically detectable hemoglobin radical-derived nitrone adducts. In addition, we were able to demonstrate the presence of hemoglobin radical-derived nitrone adducts inside red blood cells exposed to H2O2 and DMPO. In conclusion, our new approach showed several advantages over EPR spin trapping with the anti-DMPO nitrone adduct antiserum by demonstrating the formation of tyrosyl radical-derived nitrone adduct(s) in human oxyHb/metHb at much lower concentrations than was possible with EPR and detecting radicals inside RBC exposed to H2O2.

Ascorbic Acid↗