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Melatonin, Its Metabolites and Their Interference with Reactive Nitrogen Compounds
1Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Bürgerstr. 50, D-37073 Göttingen, Germany.
Molecules (Basel, Switzerland)
|July 19, 2021
Summary
Melatonin and its metabolites impact reactive nitrogen species. N1-acetyl-5-methoxykynuramine (AMK), a key metabolite, scavenges reactive nitrogen and forms stable adducts, suggesting a significant protective role.
Area of Science:
- Biochemistry
- Physiology
- Pharmacology
Background:
- Melatonin is synthesized in tissues at levels far exceeding circulation.
- Melatonin metabolites are less studied but may play crucial physiological roles.
- Reactive nitrogen species (RNS) are involved in various biological processes and pathologies.
Purpose of the Study:
- To investigate the interaction between melatonin, its metabolites, and reactive nitrogen species.
- To elucidate the specific roles of N1-acetyl-5-methoxykynuramine (AMK) in modulating RNS.
- To explore the potential protective mechanisms involving melatonin metabolites.
Main Methods:
- Investigated the effects of melatonin and AMK on nitric oxide (NO) synthases.
- Assessed the scavenging activities of melatonin and AMK towards NO and other RNS.
- Analyzed the products formed from the reaction of melatonin and AMK with RNS.
- Explored the potential involvement of protein AMKylation.
Main Results:
- Both melatonin and AMK downregulate inducible and inhibit neuronal NO synthases.
- Melatonin and AMK scavenge NO; however, melatonin's NO adduct can redonate NO, while AMK forms a stable product.
- AMK effectively scavenges carbonate radicals and NO2, products derived from peroxynitrite.
- Oxidative processes generate other melatonin metabolites with nitrosylatable sites.
Conclusions:
- Melatonin and its metabolites significantly interfere with reactive nitrogen metabolism.
- AMK plays a crucial role in neutralizing reactive nitrogen species by forming stable adducts.
- Protein AMKylation may represent an important protective mechanism against RNS-induced damage.
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