|
|
||||||||
Lipids and Lipoproteins |
a Author for correspondence. Fax 503-494-6986; e-mail duellb{at}ohsu.edu.
Melatonin has been suggested as a potent antioxidant that may protect
against development of atherosclerosis and cancer; however, these
effects are unproven and controversial. The antioxidant capacity of
melatonin was tested in comparison with
-tocopherol, ascorbic acid,
and the melatonin precursors tryptophan and serotonin, by measuring
inhibition of metal ion-mediated and human macrophage-mediated
oxidation of LDL. Melatonin had weak antioxidant activity that was
detectable only at concentrations 10 000- to 100 000-fold higher than
physiologic concentrations. These results were comparable with
published data showing that the radical scavenging activity of
melatonin requires markedly supraphysiologic concentrations. In
contrast,
-tocopherol was 50- to 100-fold more potent and was
efficacious at physiologic concentrations. Ascorbic acid and tryptophan
also were active at physiologic concentrations and were significantly
more potent than melatonin. In summary, extremely supraphysiologic
concentrations of melatonin had only weak antioxidant activity, which
was surpassed by
-tocopherol, ascorbic acid, and tryptophan.
The following articles in journals at HighWire Press have cited this article:
![]() |
V. N. Anisimov Effects of Exogenous Melatonin--A Review Toxicol Pathol, October 1, 2003; 31(6): 589 - 603. [Abstract] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |