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PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2005-9-23
pubmed:abstractText
Melatonin and N-acetylserotonin (NAS) have antioxidant properties. In the present study, we examined whether melatonin, NAS, and N-acetyldopamine (NAD) have a modulatory effect on tumor necrosis factor-alpha (TNF-alpha) synthesis and superoxide production. Differentiated THP-1-derived human monocytes were coincubated with Escherichia coli lipopolysaccharide (LPS) and rising concentrations of melatonin, NAS, or NAD. After 24 h, TNF-alpha was measured in cell supernatants. In addition, the production of superoxide by HL-60-derived human neutrophils upon stimulation with 4-beta-phorbol 12-beta-myristate 13-alpha-acetate (PMA) or N-formyl methionyl-leucyl-phenylalanine (fMLP) and increasing concentrations of melatonin, NAS, or NAD was determined. Incubation of THP-1-derived monocytes with increasing concentrations of melatonin, NAS, or NAD resulted in a marked decrease in LPS-stimulated TNF-alpha production, which was dose-dependent and on the order of 96-98%. Incubation of HL-60-derived neutrophils with increasing concentrations of melatonin, NAS, or NAD resulted in a modest decrease in PMA-stimulated superoxide production, which was dose-dependent. At the 100 microM dose, melatonin, NAS, or NAD resulted in a 14 +/- 4%, 30 +/- 1%, and 29 +/- 1% decrease in PMA-stimulated superoxide production, respectively. Coincubation of HL-60 cells with melatonin, NAS, or NAD also resulted in a modest dose-dependent decrease in fMLP-stimulated superoxide production. At the 100 microM dose, melatonin, NAS, or NAD resulted in a 13 +/- 1%, 14 +/- 1%, and 14 +/- 1% decrease in superoxide production, respectively. Our results indicate that the inhibitory effect of melatonin, NAS, or NAD on LPS-induced TNF-alpha production is robust and dose-dependent. These compounds are equally effective in attenuating the generation of oxidant radicals, although to a lesser degree.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0077-8923
pubmed:author
pubmed:issnType
Print
pubmed:volume
1053
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
386-93
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Immune-modulating effects of melatonin, N-acetylserotonin, and N-acetyldopamine.
pubmed:affiliation
Division of Nephrology, Department of Medicine, Caritas St. Elizabeth's Medical Center, Tufts University School of Medicine, 736 Cambridge Street, Boston, Massachusetts 02135, USA.
pubmed:publicationType
Journal Article