Prooxidant mechanisms of selenium toxicity - A review

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Selenium is an essential trace element in living organisms as integral part of seleno-enzymes. However, excess amount of selenium is toxic for so-called non-accumulator plants, animals and humans. The toxicity for plants depends on the capacity of synthesis of non-protein amino acids and also their volatilization in the form of dimethylselenide, while in animals on the rate of methylation and its excretion. In vitro studies showed that there are selenium-resistant animal and human cell lines which showed altered selenium uptake. Exact mechanism of selenium toxicity remains unclear but there are many data about its prooxidant effect particularly in the form of selenite, while selenomethionine and selenocysteine are less toxic. Inorganic forms of selenium reacts w i th tissue thiols, such as glutathione to form selenotrisulphides and those are reacting with other thiols to generate oxygen free radicals, such as superoxide anion. Organic diselenides are converted into selenols in presence of thiols which also results oxygen free radical generation. Another free radical hypothesis of selenium toxicosis is based on the methyl-selenide formation, which also results superoxide radicals and induce oxidative stress. Besides free radical formation selenium can have inhibitory effects on thiol proteins, for instance those which have antioxidant affect.

Original languageEnglish
Pages (from-to)15-18
Number of pages4
JournalActa Biologica Szegediensis
Volume53
Issue numberSUPPL. 1
Publication statusPublished - 2009

Fingerprint

Selenium
selenium
Toxicity
toxicity
thiols
Sulfhydryl Compounds
Free Radicals
Animals
Poisons
Superoxides
superoxide anion
Reactive Oxygen Species
Selenocysteine
selenocysteine
Oxygen
Selenomethionine
nonprotein amino acids
Selenious Acid
selenomethionine
oxygen

Keywords

  • Free radicals
  • Prooxidant
  • Selenium

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

Prooxidant mechanisms of selenium toxicity - A review. / Mézes, M.; Balogh, K.

In: Acta Biologica Szegediensis, Vol. 53, No. SUPPL. 1, 2009, p. 15-18.

Research output: Contribution to journalArticle

@article{887e7dd2786c4fa48f08ba143885b44d,
title = "Prooxidant mechanisms of selenium toxicity - A review",
abstract = "Selenium is an essential trace element in living organisms as integral part of seleno-enzymes. However, excess amount of selenium is toxic for so-called non-accumulator plants, animals and humans. The toxicity for plants depends on the capacity of synthesis of non-protein amino acids and also their volatilization in the form of dimethylselenide, while in animals on the rate of methylation and its excretion. In vitro studies showed that there are selenium-resistant animal and human cell lines which showed altered selenium uptake. Exact mechanism of selenium toxicity remains unclear but there are many data about its prooxidant effect particularly in the form of selenite, while selenomethionine and selenocysteine are less toxic. Inorganic forms of selenium reacts w i th tissue thiols, such as glutathione to form selenotrisulphides and those are reacting with other thiols to generate oxygen free radicals, such as superoxide anion. Organic diselenides are converted into selenols in presence of thiols which also results oxygen free radical generation. Another free radical hypothesis of selenium toxicosis is based on the methyl-selenide formation, which also results superoxide radicals and induce oxidative stress. Besides free radical formation selenium can have inhibitory effects on thiol proteins, for instance those which have antioxidant affect.",
keywords = "Free radicals, Prooxidant, Selenium",
author = "M. M{\'e}zes and K. Balogh",
year = "2009",
language = "English",
volume = "53",
pages = "15--18",
journal = "Acta Biologica Szegediensis",
issn = "1588-385X",
publisher = "University of Szeged",
number = "SUPPL. 1",

}

TY - JOUR

T1 - Prooxidant mechanisms of selenium toxicity - A review

AU - Mézes, M.

AU - Balogh, K.

PY - 2009

Y1 - 2009

N2 - Selenium is an essential trace element in living organisms as integral part of seleno-enzymes. However, excess amount of selenium is toxic for so-called non-accumulator plants, animals and humans. The toxicity for plants depends on the capacity of synthesis of non-protein amino acids and also their volatilization in the form of dimethylselenide, while in animals on the rate of methylation and its excretion. In vitro studies showed that there are selenium-resistant animal and human cell lines which showed altered selenium uptake. Exact mechanism of selenium toxicity remains unclear but there are many data about its prooxidant effect particularly in the form of selenite, while selenomethionine and selenocysteine are less toxic. Inorganic forms of selenium reacts w i th tissue thiols, such as glutathione to form selenotrisulphides and those are reacting with other thiols to generate oxygen free radicals, such as superoxide anion. Organic diselenides are converted into selenols in presence of thiols which also results oxygen free radical generation. Another free radical hypothesis of selenium toxicosis is based on the methyl-selenide formation, which also results superoxide radicals and induce oxidative stress. Besides free radical formation selenium can have inhibitory effects on thiol proteins, for instance those which have antioxidant affect.

AB - Selenium is an essential trace element in living organisms as integral part of seleno-enzymes. However, excess amount of selenium is toxic for so-called non-accumulator plants, animals and humans. The toxicity for plants depends on the capacity of synthesis of non-protein amino acids and also their volatilization in the form of dimethylselenide, while in animals on the rate of methylation and its excretion. In vitro studies showed that there are selenium-resistant animal and human cell lines which showed altered selenium uptake. Exact mechanism of selenium toxicity remains unclear but there are many data about its prooxidant effect particularly in the form of selenite, while selenomethionine and selenocysteine are less toxic. Inorganic forms of selenium reacts w i th tissue thiols, such as glutathione to form selenotrisulphides and those are reacting with other thiols to generate oxygen free radicals, such as superoxide anion. Organic diselenides are converted into selenols in presence of thiols which also results oxygen free radical generation. Another free radical hypothesis of selenium toxicosis is based on the methyl-selenide formation, which also results superoxide radicals and induce oxidative stress. Besides free radical formation selenium can have inhibitory effects on thiol proteins, for instance those which have antioxidant affect.

KW - Free radicals

KW - Prooxidant

KW - Selenium

UR - http://www.scopus.com/inward/record.url?scp=77951844557&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77951844557&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:77951844557

VL - 53

SP - 15

EP - 18

JO - Acta Biologica Szegediensis

JF - Acta Biologica Szegediensis

SN - 1588-385X

IS - SUPPL. 1

ER -