High-dose ascorbic acid induces carcinostatic effects through hydrogen peroxide and superoxide anion radical generation-induced cell death and growth arrest in human tongue carcinoma cells

Catechin exhibits numerous physiological characteristics. In this study, we determined the photosensitivity of catechin to various lights under alkaline conditions, and the mechanisms by which catechin generates free radical species and polymerizes via a photoreaction. In addition to this, the application of catechin photolysis was investigated. A solution of catechin is transparent, but turns yellowish under blue light illumination (BLI) in neutral or weak alkaline solutions. When catechin is subjected to BLI, a dimeric catechin (proanthocyanidin) and a superoxide anion radical (O2•−) are generated in a photolytic reaction. When ascorbic acid or gallic acid is added to catechin and the mixture is subjected to BLI at alkaline pH, fewer catechin dimers and less O2•− are produced, because both acids inhibit the photosensitive oxidation of catechin. When AlCl3 is added to catechin and the mixture is subjected to BLI at pH 8, a photolytic reaction is suppressed by AlCl3, and AlCl3 acts as a catalyst for the disconnection of proanthocyanidin during photolysis. Under alkaline conditions, catechin generates O2•− via photosensitive oxidation, which suppresses the growth of Acinetobacter baumannii (A. baumannii) by at least 4 logs, and deactivates its multi-drug-resistant strain. This study shows that catechin photolysis is a process of oxidation, and that it can be safely applied as a tool for environmental applications.

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Peer Review #3 of "Real-time monitoring of superoxide anion radical generation in response to wounding: electrochemical study (v0.2)"

10.7287/peerj.3050v0.2/reviews/3 ◽

2017 ◽

Keyword(s):

Peer Review ◽

Real Time ◽

Superoxide Anion ◽

Anion Radical ◽

Superoxide Anion Radical ◽

Electrochemical Study ◽

Real Time Monitoring ◽

Radical Generation

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γ-secretase inhibitors exerts antitumor activity via down-regulation of Notch and Nuclear factor kappa B in human tongue carcinoma cells

Oral Diseases ◽

10.1111/j.1601-0825.2006.01334.x ◽

2007 ◽

Vol 13 (6) ◽

pp. 555-563 ◽

Cited By ~ 28

Author(s):

J Yao ◽

L Duan ◽

M Fan ◽

X Wu

Keyword(s):

Antitumor Activity ◽

Nuclear Factor Kappa B ◽

Carcinoma Cells ◽

Nuclear Factor ◽

Tongue Carcinoma ◽

Down Regulation ◽

Nuclear Factor Kappa ◽

Human Tongue

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Research of corrosion fracture of D16t and AMg6 aluminum alloys exposed to microscopic fungi

Voprosy Materialovedeniya ◽

10.22349/1994-6716-2021-107-3-163-183 ◽

2021 ◽

pp. 163-183

Author(s):

D. V. Belov ◽

S. N. Belyaev ◽

M. V. Maksimov ◽

G. A. Gevorgyan

Keyword(s):

Hydrogen Peroxide ◽

Aluminum Alloys ◽

Superoxide Anion ◽

Anion Radical ◽

Corrosion Damage ◽

Oxygen Species ◽

Microscopic Fungi ◽

Reductive Activation ◽

Activation Of Oxygen

This paper presents an experimental study of biocorrosion of D16T and AMg6 aluminum alloys. The determining role of reactive oxygen species in aluminum biocorrosion by a consortium of molds has been shown. A model is proposed, according to which the initiators of corrosion damage to the metal surface are superoxide anion radical and hydrogen peroxide released during the life of micromycetes. It is assumed that the initiation and development of biocorrosion occurs, among other things, as a result of the process of reductive activation of oxygen and the Fenton decomposition of hydrogen peroxide. A conclusion is made about the mechanism of the occurrence of intergranular and pitting corrosion of aluminum alloys interacting with microscopic fungi.

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