Linked Life Data

1824684

Source:http://linkedlifedata.com/resource/pubmed/id/1824684

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-2-14
pubmed:abstractText
Methylated selenides are prominent metabolites at the dietary levels used for obtaining anticarcinogenic effects with selenium. The present study reports the chemopreventive activities of 2 novel selenium compounds, Se-methylselenocysteine and dimethyl selenoxide, in the rat dimethylbenz(a)anthracene-induced mammary tumor model. Other treatment groups were supplemented with either selenite or selenocystine for comparative purposes. Each selenium compound was tested at different levels and was given to the animal starting 1 week before dimethylbenz(a)anthracene administration and continued until sacrifice. Results of the carcinogenesis experiments showed that the relative efficacy with the four compounds was Se-methylselenocysteine greater than selenite greater than selenocystine greater than dimethyl selenoxide. In correlating the chemical form and metabolism of these selenium compounds with their anticarcinogenic activity, it is concluded that: (a) selenium compounds that are able to generate a steady stream of methylated metabolites, particularly the monomethylated species, are likely to have good chemopreventive potential; (b) anticarcinogenic activity is lower for selenoamino acids, such as selenocysteine following conversion from selenocystine, which have an escape mechanism via random, nonstoichiometric incorporation into proteins; and (c) forms of selenium, as exemplified by dimethyl selenoxide, which are metabolized rapidly and quantitatively to dimethyl selenide and trimethylselenonium and excreted, are likely to be poor choices. We also undertook a separate bioavailability study using Se-methylselenocysteine, dimethyl selenoxide, and trimethylselenonium as the starting compounds for delivering selenium with one, two, or three methyl groups, and measured the ability of these compounds to restore glutathione peroxidase activity in selenium-depleted animals. All three compounds were able to fully replete this enzyme, although with a wide range of efficiency (Se-methylselenocysteine greater than dimethyl selenoxide greater than trimethylselenonium), suggesting that complete demethylation to inorganic selenium is a normal process of selenium metabolism. However, the degree to which this occurs under chemoprevention conditions would argue against the involvement of selenoproteins in the anticarcinogenic action of these selenium compounds.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/9,10-Dimethyl-1,2-benzanthracene, http://linkedlifedata.com/resource/pubmed/chemical/Antineoplastic Agents, http://linkedlifedata.com/resource/pubmed/chemical/Arsenic, http://linkedlifedata.com/resource/pubmed/chemical/Arsenites, http://linkedlifedata.com/resource/pubmed/chemical/Cysteine, http://linkedlifedata.com/resource/pubmed/chemical/Glutathione Peroxidase, http://linkedlifedata.com/resource/pubmed/chemical/Organoselenium Compounds, http://linkedlifedata.com/resource/pubmed/chemical/Oxides, http://linkedlifedata.com/resource/pubmed/chemical/Selenious Acid, http://linkedlifedata.com/resource/pubmed/chemical/Selenium, http://linkedlifedata.com/resource/pubmed/chemical/Selenocysteine, http://linkedlifedata.com/resource/pubmed/chemical/arsenite, http://linkedlifedata.com/resource/pubmed/chemical/selenomethylselenocysteine
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
595-600
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Chemical form of selenium, critical metabolites, and cancer prevention.
pubmed:affiliation
Department of Breast Surgery, Roswell Park Cancer Institute, Buffalo, New York 14263.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't