Melatonin—A Highly Potent Endogenous Radical Scavenger and Electron Donor: New Aspects of the Oxidation Chemistry of this Indole Accessed in vitro a

  title={Melatonin—A Highly Potent Endogenous Radical Scavenger and Electron Donor: New Aspects of the Oxidation Chemistry of this Indole Accessed in vitro a},
  author={Burkhard Poeggeler and Seppo Y O Saarela and Russel Joseph Reiter and DUN‐XIAN TAN and LI‐DUN CHEN and Lucien C. Manchester and Lornell Barlow-Walden},
  journal={Annals of the New York Academy of Sciences},
Endogenous indolamines derived from the essential aromatic amino acid tryptophan can act as substrates and mediators of electron transfer mechanisms and radical reactions.' The indoleamine melatonin is the most powerful and effective hydroxyl radical scavenger detected to date, which, due to its lipophilic nature, provides on-site protection against oxidative damage to biomolecules within every cell compartment.',* 
Melatonin and structurally-related, endogenous indoles act as potent electron donors and radical scavengers in vitro.
Melatonin was the most potent radical scavenger and electron donor when compared with the methoxylated indole analogs and the other antioxidants tested and acted as potent electron donors which scavenged initiating and propagating radicals and repaired oxidative damage due to electrophile intermediates. Expand
Actions of melatonin in the reduction of oxidative stress. A review.
Melatonin was discovered to be a direct free radical scavenger less than 10 years ago. Besides its ability to directly neutralize a number of free radicals and reactive oxygen and nitrogen species,Expand
Pharmacological actions of melatonin in oxygen radical pathophysiology.
Whether the quantity of melatonin produced in vertebrate species is sufficient to significantly influence the total antioxidative defense capacity of the organism remains unknown, but its pharmacological benefits seem assured considering the low toxicity of the molecule. Expand
Biochemical reactivity of melatonin with reactive oxygen and nitrogen species
In vitro melatonin acts as a direct free radical scavenger with the ability to detoxify both reactive oxygen and reactive nitrogen species; in vivo, it is an effective pharmacological agent in reducing oxidative damage under conditions in which excessive free radical generation is believed to be involved. Expand
Endogenous and Dietary Indoles: A Class of Antioxidants and Radical Scavengers in the ABTS Assay
Radical scavenger activity of indoles against ABTS•+ was higher at physiological pH than at low pH, pointing out to structural compounds with an indole moiety as a class of radical scavengers and antioxidants. Expand
NO‐donor melatonin derivatives: synthesis and in vitro pharmacological characterization
It is known that atherosclerosis progression involves ROS‐induced oxidation of low‐density lipoproteins in sub‐endothelial space and the depletion of nitric oxide in blood vessels, as well as a decreased sensitivity of the vessels to the actions of NO, so a series of new NO‐donor antioxidants were designed and synthesized as polyvalent agents potentially useful for the treatment of cardiovascular diseases involving atherosclerotic vascular changes. Expand
A Review of Biological and Pharmacological Actions of Melatonin: Oxidant and Prooxidant Properties
Although melatonin could potentially be useful but safety, efficacy remains uncertain, the studies which document the influence of melatonin on the various oxidative stress associated diseases are reviewed. Expand
Melatonin: a well‐documented antioxidant with conditional pro‐oxidant actions
Although the vast majority of studies proved the antioxidant capacity of melatonin and its derivatives, a few studies using cultured cells found that melatonin promoted the generation of ROS at pharmacological concentrations in several tumor and nontumor cells; thus, melatonin functioned as a conditional pro‐oxidant. Expand
The indoleamine melatonin as a free radical scavenger, electron donor, and antioxidant. In vitro and in vivo studies.
  • R. Reiter
  • Chemistry, Medicine
  • Advances in experimental medicine and biology
  • 1996
Following its discovery in bovine pineal tissue in the late 1950s, melatonin was functionally linked to the reproductive system (Hoffman and Reiter, 1965) and shown to depend on its sympathetic innervation for its activity. Expand
A Novel Endogenous Indole Protects Rodent Mitochondria and Extends Rotifer Lifespan
The results suggest that IPAM reversed the age-dependent decline of mitochondrial energetic capacity and increased rotifer lifespan, and it may, in fact, constitute a novel endogenous anti-aging substance of physiological importance. Expand


Melatonin, hydroxyl radical‐mediated oxidative damage, and aging: A hypothesis
Experiments investigating the effects of endogenous excitatory amino acid antagonists and stimulants of melatonin biosynthesis such as magnesium may finally lead to novel therapeutic approaches for the prevention of degeneration and dysdifferentiation associated with diseases related to premature aging. Expand
Melatonin As a Free Radical Scavenger: Implications for Aging and Age‐Related Diseases a
This recently discovered function of melatonin establishes a role for this indole in every organism, and indeed in every cell, from the most primitive members of the animal kingdom up to and including the was shown to be a hormone produced in and secreted from the mammalian pineal gland. Expand