Linked Life Data

9838210

Source:http://linkedlifedata.com/resource/pubmed/id/9838210

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-1-28
pubmed:abstractText
The direct effects of the neurohormone melatonin on reactive oxygen species (ROS) were investigated. Melatonin was found to inhibit DMPO-O-2 formation in a dose-dependent manner. At the level of 1. 7+/-0.07 mM, melatonin caused 50% inhibition of EPR signal intensity of DMPO-O-2 during the reaction of xanthine and xanthine oxidase. The reaction rate constant of melatonin with O2- was found to be 1.25+/-0.07x103 M-1 s-1. However, melatonin (up to 1.2 mM) did not exhibit significant effect toward OH radical, produced by the Fenton reaction. In addition, we found no evidence for the formation of the melatonin indolyl cation radical that presumably precedes conversion of melatonin to its stable N1-acetyl-N2-5-methoxykynuramine (AMK) metabolite following sequential reactions of melatonin with O2- and OH. On the other hand, melatonin was capable of scavenging H2O2 in a dose-dependent manner with an IC50=0.5+/-0.02 mM. The reaction rate constant of melatonin with H2O2 was found to be 2.52+/-0.19x105 M-1 s-1. Furthermore, melatonin was also found to inhibit 1O2-dependent 2,2,6,6-tetramethylpiperidine oxide (TEMPO) radical formation during rose bengal photodynamic reaction. The results suggest that melatonin's antioxidant properties, in part, may involve a direct effect on scavenging of ROS.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
1425
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
469-77
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Scavenging of reactive oxygen species by melatonin.
pubmed:affiliation
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505-2888, USA. laz7@cdc.gov
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.