Dramatic Rises of Melatonin and 5-Methoxytryptamine in Gonyaulax Exposed to Decreased Temperature

Fuhrberg, B.; Hardeland, Ruediger; Pöeggeler, Burkhard; Behrmann, C.

doi:10.1076/brhm.28.1.144.12978

Cited by 41 publications

(38 citation statements)

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“…It has been reported that the high melatonin-containing tobacco is more resistant to UV irradiation than that is the low melatonin tabacco strain [16]. In a unicellular organism (Gonyaulax polyedra) when the ambient temperature of the culture is decreased, the organism increases melatonin production to adapt to cold stress to ensure survival [17].…”

Section: Introductionmentioning

confidence: 99%

Chemical and Physical Properties and Potential Mechanisms: Melatonin as a Broad Spectrum Antioxidant and Free Radical Scavenger

Tan

Reíter

Manchester

et al. 2002

CTMC

933

710

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Melatonin was found to be a potent free radical scavenger in 1993. Since then over 800 publications have directly or indirectly confirmed this observation. Melatonin scavenges a variety of reactive oxygen and nitrogen species including hydroxyl radical, hydrogen peroxide, singlet oxygen, nitric oxide and peroxynitrite anion. Based on the analyses of structure-activity relationships, the indole moiety of the melatonin molecule is the reactive center of interaction with oxidants due to its high resonance stability and very low activation energy barrier towards the free radical reactions. However, the methoxy and amide side chains also contribute significantly to melatonin's antioxidant capacity. The N-C=O structure in the C3 amide side chain is the functional group. The carbonyl group in the structure of N-C=O is key for melatonin to scavenge the second reactive species and the nitrogen in the N-C=O structure is necessary for melatonin to form the new five membered ring after melatonin's interaction with a reactive species. The methoxy group in C5 appears to keep melatonin from exhibiting prooxidative activity. If the methoxy group is replaced by a hydroxyl group, under some in vitro conditions, the antioxidant capacity of this molecule may be enhanced. However, the cost of this change are decreased lipophility and increased prooxidative potential. Therefore, in in vivo studies the antioxidant efficacy of melatonin appears to be superior to its hydroxylated counterpart. The mechanisms of melatonin's interaction with reactive species probably involves donation of an electron to form the melatoninyl cation radical or through an radical addition at the site C3. Other possibilities include hydrogen donation from the nitrogen atom or substitution at position C2, C4 and C7 and nitrosation. Melatonin also has the ability to repair damaged biomolecules as shown by the fact that it converts the guanosine radical to guanosine by electron transfer. Unlike the classical antioxidants, melatonin is devoid of prooxidative activity and all known intermediates generated by the interaction of melatonin with reactive species are also free radical scavengers. This phenomenon is defined as the free radical scavenging cascade reaction of the melatonin family. Due to this cascade, one melatonin molecule has the potential to scavenge up to 4 or more reactive species. This makes melatonin very effective as an antioxidant. Under in vivo conditions, melatonin is often several times more potent than vitamin C and E in protecting tissues from oxidative injury when compared at an equivalent dosage (micromol/kg). Future research in the field of melatonin as a free radical scavenger might be focused on: 1), signal transduction and antioxidant enzyme gene expression induced by melatonin and its metabolites, 2), melatonin levels in tissues and in cells, 3), melatonin structure modifications, 4), melatonin and its metabolites in plants and, 5), clinical trials using melatonin to treat free radical related diseases such as Alzheimer's, Parkinson's, s...

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Section: Introductionmentioning

confidence: 99%

Chemical and Physical Properties and Potential Mechanisms: Melatonin as a Broad Spectrum Antioxidant and Free Radical Scavenger

Tan

Reíter

Manchester

et al. 2002

CTMC

933

710

View full text Add to dashboard Cite

show abstract

“…data), signalling may involve 5MT formation; this metabolite has strong effects on proton transfer from an acidic vacuole system, and the effects on encystment as well as on bioluminescence can be mimicked by protonophores [13,15,17]. Moreover, inhibitors of monoamine oxidase, which cause the accumulation of 5MT to cyst-inducing concentrations [12,15], also elicited the two responses [13][14][15]17]. Therefore, the question is how findings on rises in 5MT, signalled by proton transfer and effects on calcium and inositol phosphates, as found in Crypthecodinium [38,39], can be matched; that is, in which temporal and functional sequence such events will interact.…”

Section: Occurrence Of and Responses To 5-methoxytryptaminementioning

confidence: 99%

“…5MT was also shown to be required for the expression of the circadian glow peak in Gonyaulax polyedra [ 19]. The conversion of melatonin to 5MT, due to the observed induction of a melatonin-deacetylating aryl acylamidase, is suggested to be the crucial step in the encystment response of this species [12,15,17,18]. Since no high-affmity binding sites for melatonin were detected in Gonyaulax (Masson-P6vet M., Balzer I., unpubl.…”

Section: Occurrence Of and Responses To 5-methoxytryptaminementioning

confidence: 99%

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Melatonin and 5-methoxytryptamine in non-metazoans

Hardeland

1999

Reprod. Nutr. Dev.

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“…Recently, in non-metazoans, for example, bacteria, protistans, fungi, algae, and plants, melatonin is formed by shikimic acid pathway, where tryptophan is first synthesized using D-erythrose-4-phosphate, phosphoenolpyruvate, and carbon dioxide (Bochkov et al 2012). Therefore, melatonin synthesis in these organisms is not limited by tryptophan as an initial source, and this leads to exceptionally higher yield of melatonin generally better than those in higher vertebrates (Fuhrberg et al 1997;Chen et al 2003;Hardeland et al 2007). In vertebrates, melatonin synthesis has been broadly studied (Hardeland 2010).…”

Section: Synthesis and Regulation Of Melatoninmentioning

confidence: 94%

Microbial Source of Melatonin and Its Clinical Aspects

Kumar¹,

Mulligan²,

Ojha

et al. 2017

Microbial Applications Vol.2

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Melatonin chemically known as N-acetyl-5-methoxytryptamine is a small physiological compound of diversified functions. Melatonin has been found in phylogenetically different taxa of bacteria, unicellular eukaryote, microalgae, plants, fungi, and animals. Identification of melatonin in many of these microorganisms is missing, and its function is rarely known. Although, melatonin in microorganisms is not essentially involved in circadian process, rather, it exhibits antioxidant property also and may protect chlorophyll pigment to damage from stress and free radicals. Mostly, the pathway for melatonin synthesis in microorganisms shows similarity with vertebrates. Investigation on melatonin in some organisms allows more concrete discussion about their possible role. The various functions of melatonin in human including sleep and regulation of circadian rhythm has been well characterized. Here, we have focused on the mechanism of immune regulatory, antioxidant, and scavenging property of melatonin during pathogenesis caused by fungi, bacteria, and virus. This article will provide a view on microbial sources and possible therapeutic aspects of melatonin in future.

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Dramatic Rises of Melatonin and 5-Methoxytryptamine in Gonyaulax Exposed to Decreased Temperature

Cited by 41 publications

References 0 publications

Chemical and Physical Properties and Potential Mechanisms: Melatonin as a Broad Spectrum Antioxidant and Free Radical Scavenger

Chemical and Physical Properties and Potential Mechanisms: Melatonin as a Broad Spectrum Antioxidant and Free Radical Scavenger

Melatonin and 5-methoxytryptamine in non-metazoans

Microbial Source of Melatonin and Its Clinical Aspects

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