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.',* 
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,
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.
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.
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.
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.
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.
The indoleamine melatonin as a free radical scavenger, electron donor, and antioxidant. In vitro and in vivo studies.
  • R. Reiter
  • Biology
    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.
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.
Melatonin and nitric oxide
In conclusion, inhibition of NO production may be another means whereby melatonin reduces oxidative damage under conditions, such as ischemia-reperfusion, sepsis, etc, where NO seems to be important in terms of the resulting damage.
Free radical scavenging and antioxidative activity of melatonin derivatives
The preliminary evaluation indicated that compound 4c showed improved scavenging activity compared with vitamin C and suggested that the cysteinyl‐conjugated derivative 4c may be a suitable lead to further optimize potent antioxidants for certain oxidative stress conditions.


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.
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.