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Article
Melatonin inhibits Gram-negative pathogens by targeting citrate synthase
Bacterial infections caused by Gram-negative pathogens represent a growing burden for public health worldwide. Despite the urgent need for new antibiotics that effectively fight against pathogenic bacteria, ve...
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Article
Open AccessAddressing the ‘hypoxia paradox’ in severe COVID-19: literature review and report of four cases treated with erythropoietin analogues
Since fall 2019, SARS-CoV-2 spread world-wide, causing a major pandemic with estimated ~ 220 million subjects affected as of September 2021. Severe COVID-19 is associated with multiple organ failure, particula...
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Article
Open AccessInducing sterile pyramidal neuronal death in mice to model distinct aspects of gray matter encephalitis
Up to one person in a population of 10,000 is diagnosed once in lifetime with an encephalitis, in 50–70% of unknown origin. Recognized causes amount to 20–50% viral infections. Approximately one third of affec...
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Article
Melatonergic Sleep Promotion: Fundamental Chronobiological Issues Concerning Sleep Onset and Maintenance, Dose and Duration of Action
This review summarizes the conditions under which sleep promotion by melatonin or other melatonergic drugs can be successfully achieved or not. Importantly, the chronobiological rules are outlined which have t...
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Article
Melatonin and the electron transport chain
Melatonin protects the electron transport chain (ETC) in multiple ways. It reduces levels of ·NO by downregulating inducible and inhibiting neuronal nitric oxide synthases (iNOS, nNOS), thereby preventing exce...
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Chapter
Melatonin in Healthy Aging and Longevity
Melatonin is a regulator of the circadian multioscillator system. It transmits the information ‘darkness’, contributes to internal and external alignment of rhythms and, presumably via sirtuin-1, to high ampli...
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Chapter
Deacceleration of Brain Aging by Melatonin
Melatonin counteracts several pathophysiological processes that promote brain aging. A central feature of these aging-accelerating changes is low-grade brain inflammation, which may progressively aggravate, es...
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Article
Melatonin Antioxidative Defense: Therapeutical Implications for Aging and Neurodegenerative Processes
The pineal product melatonin has remarkable antioxidant properties. It is secreted during darkness and plays a key role in various physiological responses including regulation of circadian rhythms, sleep homeo...
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Article
Open AccessMeasurement of melatonin in body fluids: Standards, protocols and procedures
The circadian rhythm of melatonin in saliva or plasma, or of the melatonin metabolite 6-sulfatoxymelatonin (a6MTs) in urine, is a defining feature of suprachiasmatic nucleus (SCN) function, the body’s endogeno...
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Article
Ramelteon: a review of its therapeutic potential in sleep disorders
Ramelteon is a tricyclic synthetic analog of melatonin that acts specifically on MT1 and MT2 melatonin receptors. Ramelteon’s half-life is longer than that of melatonin, being metabolized in the body to four main...
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Article
Drug Insight: the use of melatonergic agonists for the treatment of insomnia—focus on ramelteon
Melatonin has been used successfully to treat insomnia, but has not received regulatory approval by the FDA because it can be sold freely as a food supplement. This has prompted a search by pharmaceutical comp...
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Article
Antioxidant activity in Spalax ehrenbergi: a possible adaptation to underground stress
The blind subterranean mole rat Spalax ehrenbergi superspecies has evolved adaptive strategies to cope with underground stress. Hypoxia is known to stimulate reactive oxygen species generation; however, mechanism...
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Article
Open AccessMelatonin, a potent agent in antioxidative defense: Actions as a natural food constituent, gastrointestinal factor, drug and prodrug
Melatonin, originally discovered as a hormone of the pineal gland, is also produced in other organs and represents, additionally, a normal food constituent found in yeast and plant material, which can influenc...
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Chapter
An Ancient Cellular Mechanism in the Tension Field between Energy Requirements and Destruction Avoidance
Circadian rhythmicity is a fundamental biological phenomenon of almost ubiquitous importance. This kind of an endogenous, innate oscillation with a period length of about a day is present in the majority of or...
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Chapter
Circadian Rhythms and Oxidative Stress in Non-vertebrate Organisms
Several lines of evidence suggest that the circadian organization of living beings is important for avoiding excessive oxidative stress under physiological conditions. In the dinoflagellate Gonyaulax polyedra, ac...
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Article
New actions of melatonin and their relevance to biometeorology
Melatonin is not only produced by the pineal gland, retina and parietal but also by various other tissues and cells from vertebrates, invertebrates, fungi, plants, multicellular algae and by unicells. In plan...
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Article
The vertebrate pineal hormone melatonin is produced by the brown alga Pterygophora californica and mimics dark effects on growth rate in the light
Melatonin, a methoxylated indoleamine, plays a role as a mediator of darkness in animals as well as in the unicellular alga Gonyaulax polyedra Stein and was recently detected in higher plants. We report on the fi...
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Article
Circadian rhythmicity in the stimulation of bioluminescence by biogenic amines and MAO inhibitors inGonyaulax polyedra
In the dinoflagellateGonyaulax polyedra bioluminescence was investigated in constant darkness. Light emission was stimulated considerably and specifically by the biogenic smines epinephrine, 5-methoxytryptamine, ...
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Article
Differential light effects on the dark motility rhythm inEuglena gracilis by series of short light pulses: Induction of long-term fluctuations and holding of the circadian oscillator
Dark motility was measured by means of an infrared beam in stationary, 8- to 10-months-old autotrophic cultures ofEuglena gracilis, strain Z. Controls in constant darkness exhibited circadian rhythms for several ...
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Article
Ultradian rhythmicity of tyrosine aminotransferase activity inEuglena gracillis: Analysis by cosine and non-sinusoidal fitting procedures
Although the geophysical periodicity of the earth's rotation corresponds to a biological cyclicity of ca. 24 h, cellular temporal organization comprises a multifrequency time structure, in which ultradian rhyt...
