One molecule, many derivatives: A never‐ending interaction of melatonin with reactive oxygen and nitrogen species?

Journal of Pineal Research, Год журнала: 2006, Номер 42(1), С. 28 - 42

Опубликована: Ноя. 29, 2006

Melatonin is a highly conserved molecule. Its presence can be traced back to ancient photosynthetic prokaryotes. A primitive and primary function of melatonin that it acts as receptor-independent free radical scavenger broad-spectrum antioxidant. The receptor-dependent functions were subsequently acquired during evolution. In the current review, we focus on metabolism which includes synthetic rate-limiting enzymes, sites, potential regulatory mechanisms, bioavailability in humans, mechanisms breakdown its metabolites. Recent evidence indicates original metabolite may N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) rather than commonly measured urinary excretory product 6-hydroxymelatonin sulfate. Numerous pathways for AFMK formation have been identified both vitro vivo. These include enzymatic pseudo-enzymatic pathways, interactions with reactive oxygen species (ROS)/reactive nitrogen (RNS) ultraviolet irradiation. present mammals including only detectable unicellular organisms metazoans. sulfate has not observed these low evolutionary-ranked organisms. This implies evolved earlier evolution metabolite. Via pathway, single molecule reported scavenge up 10 ROS/RNS. That scavenging capacity extends secondary, tertiary quaternary metabolites now documented. It appears melatonin's interaction ROS/RNS prolonged process involves many derivatives. by successively referred cascade. cascade reaction novel property explains how differs from other conventional antioxidants. makes effective, even at concentrations, protecting oxidative stress. accordance protective function, substantial amounts are found tissues organs frequently exposed hostile environmental insults such gut skin or high consumption brain. addition, production upregulated intensity stressors dietary restriction rats exercise humans. Intensive stress results rapid drop circulating levels. decline related reduced synthesis but consumption, i.e. rapidly metabolized induced Rapid elevated serve mechanism used first-line defensive against damage. status modifies metabolism. higher state, more produced. ratio another metabolite, cyclic 3-hydroxymelatonin, an indicator level

Язык: Английский

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Actions of melatonin in the reduction of oxidative stress

Journal of Biomedical Science, Год журнала: 2000, Номер 7(6), С. 444 - 458

Опубликована: Ноя. 1, 2000

Язык: Английский

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Extrapineal melatonin: sources, regulation, and potential functions

Cellular and Molecular Life Sciences, Год журнала: 2014, Номер 71(16), С. 2997 - 3025

Опубликована: Фев. 19, 2014

Язык: Английский

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Oxidative damage in the central nervous system: protection by melatonin

Progress in Neurobiology, Год журнала: 1998, Номер 56(3), С. 359 - 384

Опубликована: Окт. 1, 1998

Язык: Английский

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Melatonin—A pleiotropic, orchestrating regulator molecule

Progress in Neurobiology, Год журнала: 2010, Номер 93(3), С. 350 - 384

Опубликована: Дек. 29, 2010

Язык: Английский

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On the free radical scavenging activities of melatonin's metabolites, AFMK and AMK

Journal of Pineal Research, Год журнала: 2012, Номер 54(3), С. 245 - 257

Опубликована: Авг. 24, 2012

Abstract The reactions of N 1 ‐acetyl‐ 2 ‐formyl‐5‐methoxykynuramine ( AFMK ) and ‐acetyl‐5‐methoxykynuramine AMK with • OH , OOH OOCC l 3 radicals have been studied using the density functional theory. Three mechanisms reaction considered: radical adduct formation RAF ), hydrogen transfer HT single electron SET ). Their relative importance for free scavenging activity has assessed. It was found that react at diffusion‐limited rates, regardless polarity environment, which supports their excellent activity. Both compounds were to be also very efficient but rather ineffective . Regarding activity, it systematically is a poorer scavenger than melatonin. In aqueous solution, faster melatonin all radicals, while in nonpolar environments, efficiency as scavengers depends on they are reacting. Under such conditions, predicted better slightly Accordingly seems its metabolite constitute an team able deactivating wide variety reactive oxygen species, under different conditions. Thus, presented results support continuous protection exerted by melatonin, through cascade.

Язык: Английский

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Biochemical Reactivity of Melatonin with Reactive Oxygen and Nitrogen Species: A Review of the Evidence

Cell Biochemistry and Biophysics, Год журнала: 2001, Номер 34(2), С. 237 - 256

Опубликована: Янв. 1, 2001

Язык: Английский

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Antioxidative Protection by Melatonin: Multiplicity of Mechanisms from Radical Detoxification to Radical Avoidance

Endocrine, Год журнала: 2005, Номер 27(2), С. 119 - 130

Опубликована: Янв. 1, 2005

Язык: Английский

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Melatonin as an antioxidant: biochemical mechanisms and pathophysiological implications in humans.

Acta Biochimica Polonica, Год журнала: 2003, Номер 50(4), С. 1129 - 1146

Опубликована: Дек. 31, 2003

This brief resume enumerates the multiple actions of melatonin as an antioxidant. indoleamine is produced in vertebrate pineal gland, retina and possibly some other organs. Additionally, however, it found invertebrates, bacteria, unicellular organisms well plants, all which do not have a gland. Melatonin's functions antioxidant include: a), direct free radical scavenging, b), stimulation antioxidative enzymes, c), increasing efficiency mitochondrial oxidative phosphorylation reducing electron leakage (thereby lowering generation), 3), augmenting antioxidants. There may be melatonin, yet undiscovered, enhance its ability to protect against molecular damage by oxygen nitrogen-based toxic reactants. Numerous vitro vivo studies documented both physiological pharmacological concentrations destruction. Furthermore, clinical tests utilizing proven highly successful; because positive outcomes these studies, melatonin's use disease states processes where involved should increased.

Язык: Английский

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Functional roles of melatonin in plants, and perspectives in nutritional and agricultural science

Journal of Experimental Botany, Год журнала: 2011, Номер 63(2), С. 577 - 597

Опубликована: Окт. 20, 2011

The presence of melatonin in plants is universal. Evidence has confirmed that a major portion the synthesized by themselves even though homologue classic arylalkylamine N-acetyltransferase (AANAT) not been identified as yet plants. Thus, serotonin N-acetylating enzyme may differ greatly from animal AANAT with regard to sequence and structure. This would imply multiple evolutionary origins enzymes these catalytic properties. A primary function serve first line defence against internal environmental oxidative stressors. much higher levels compared those found animals are thought be compensatory response which lack means mobility, unlike animals, coping harsh environments. Importantly, remarkably high concentrations have measured popular beverages (coffee, tea, wine, beer) crops (corn, rice, wheat, barley, oats). Billions people worldwide consume products daily. beneficial effects on human health derived consumption must considered. also indicates an ability increase production crops. mechanisms involve roles preservation chlorophyll, promotion photosynthesis, stimulation root development. Transgenic enhanced content could probably lead breakthroughs crop agriculture improve general humans.

Язык: Английский

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