scholarly journals Melatonin’s neuroprotective role in mitochondria and its potential as a biomarker in aging, cognition and psychiatric disorders

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lindsay M. Melhuish Beaupre ◽  
Gregory M. Brown ◽  
Vanessa F. Gonçalves ◽  
James L. Kennedy
Keyword(s):  
Psychiatric Disorders ◽  
Free Radical Scavenger ◽  
The Body ◽  
Radical Scavenger ◽  
Pineal Melatonin ◽  
Mediated Effects ◽  
Ability To Act ◽  
High Concentrations ◽  
Mitochondrial Oxidative Metabolism

AbstractMelatonin is an ancient molecule that is evident in high concentrations in various tissues throughout the body. It can be separated into two pools; one of which is synthesized by the pineal and can be found in blood, and the second by various tissues and is present in these tissues. Pineal melatonin levels display a circadian rhythm while tissue melatonin does not. For decades now, melatonin has been implicated in promoting and maintaining sleep. More recently, evidence indicates that it also plays an important role in neuroprotection. The beginning of our review will summarize this literature. As an amphiphilic, pleiotropic indoleamine, melatonin has both direct actions and receptor-mediated effects. For example, melatonin has established effects as an antioxidant and free radical scavenger both in vitro and in animal models. This is also evident in melatonin’s prominent role in mitochondria, which is reviewed in the next section. Melatonin is synthesized in, taken up by, and concentrated in mitochondria, the powerhouse of the cell. Mitochondria are also the major source of reactive oxygen species as a byproduct of mitochondrial oxidative metabolism. The final section of our review summarizes melatonin’s potential role in aging and psychiatric disorders. Pineal and tissue melatonin levels both decline with age. Pineal melatonin declines in individuals suffering from psychiatric disorders. Melatonin’s ability to act as a neuroprotectant opens new avenues of exploration for the molecule as it may be a potential treatment for cases with neurodegenerative disease.

scholarly journals Collagen-Based Electrospun Materials for Tissue Engineering: A Systematic Review

2021 ◽  
Vol 8 (3) ◽  
pp. 39
Author(s):  
Britani N. Blackstone ◽  
Summer C. Gallentine ◽  
Heather M. Powell
Keyword(s):  
Systematic Review ◽  
Tissue Engineering ◽  
Collagen Type I ◽  
The Body ◽  
Pool Data ◽  
Type I ◽  
High Concentrations ◽  
Increased Strength

Collagen is a key component of the extracellular matrix (ECM) in organs and tissues throughout the body and is used for many tissue engineering applications. Electrospinning of collagen can produce scaffolds in a wide variety of shapes, fiber diameters and porosities to match that of the native ECM. This systematic review aims to pool data from available manuscripts on electrospun collagen and tissue engineering to provide insight into the connection between source material, solvent, crosslinking method and functional outcomes. D-banding was most often observed in electrospun collagen formed using collagen type I isolated from calfskin, often isolated within the laboratory, with short solution solubilization times. All physical and chemical methods of crosslinking utilized imparted resistance to degradation and increased strength. Cytotoxicity was observed at high concentrations of crosslinking agents and when abbreviated rinsing protocols were utilized. Collagen and collagen-based scaffolds were capable of forming engineered tissues in vitro and in vivo with high similarity to the native structures.

scholarly journals Gastroprotective Value of Berries: Evidences from Methanolic Extracts of Morus nigra and Rubus niveus Fruits

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Luciane Angela Nottar Nesello ◽  
Maria Luisa Maes Lima Beleza ◽  
Marihá Mariot ◽  
Luísa Nathália Bolda Mariano ◽  
Priscila de Souza ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Free Radical Scavenger ◽  
Total Phenolic ◽  
Radical Scavenger ◽  
Lipid Hydroperoxides ◽  
Ulcer Area ◽  
Morus Nigra ◽  
Radical Scavenger Activity ◽  
Scavenger Activity

This study evaluated the gastroprotective value of the methanol extracts from fruits of Morus nigra L. (black mulberry (MEMN)) and Rubus niveus Thunb (raspberry (MERN)). The total phenolic compounds and flavonoids were measured, as well as the in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenger activity. The gastroprotective effects of the extracts against 60% ethanol/0.3 M HCl were evaluated in mice. After that, the lipid hydroperoxides and reduced glutathione levels at ulcerated tissue were determined. The effects of extracts on H+/K+-ATPase activity were also verified. The extracts exhibited high contents of polyphenols; however, MERN presented 1.5-fold higher levels. The presence of flavonoids also was confirmed. In addition, MEMN (IC50 = 13.74 μg/mL) and MERN (IC50 = 14.97 μg/mL) scavenged DPPH radical. The MEMN reduced the ulcer area only at 300 mg/kg (p.o.) by 64.06%. Interestingly, MERN decreased the ulcer area in a superior potency (ED50 = 20.88 mg/kg), reducing the ulcer area by 81.86% at 300 mg/kg, and increased the gastric mucin levels. The antioxidant effects of extracts were evidenced by reduced lipoperoxides and increased reduction of glutathione amount in the gastric mucosa. However, MEMN or MERN did not change the H+/K+-ATPase activity. These results confirm that M. nigra and R. niveus are berries with a gastroprotective value by strengthening of gastric protective factors.

scholarly journals Role of Melatonin as a Survival Factor for In vitro Development of Sheep Preantral Follicles

2021 ◽  
Author(s):  
C. Chetan Kumar ◽  
B. Rambabu Naik ◽  
A.V.N. Siva Kumar ◽  
A. Ravi ◽  
L.S.S. Varaprasad Reddy ◽  
...  
Keyword(s):  
Growth Factors ◽  
Ovarian Function ◽  
Follicular Development ◽  
Oocyte Quality ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Optimum Level ◽  
Preantral Follicles ◽  
Positive Effects

Background: Melatonin, a powerful free radical scavenger and broad-spectrum antioxidant may directly affect ovarian function by regulating folliculogenesis, maintenance of follicular integrity, oocyte quality and maturation capacity. Therefore, we aimed to study effects of melatonin and its interaction with growth factors in sheep preantral follicles. Methods: The influence of different concentrations of Melatonin (5-500 pM) on in vitro culture of preantral follicles (PFs’) isolated from sheep ovaries was studied. Experiments I and II were conducted to standardize the optimum concentration of Melatonin that supports better development of preantral follicles. Experiment III was conducted with the optimum level of Melatonin derived in the Experiments I and II to evaluate the effect of melatonin at 100pM in combination with various growth factors. Result: Overall follicular development was found to be the best in the PFs’ cultured in medium supplemented with 100pM of Melatonin. Melatonin supplementation showed positive effects on the preantral follicular development in combination with different growth factors.

scholarly journals Melatonin in Prevention of the Sequence from Reflux Esophagitis to Barrett’s Esophagus and Esophageal Adenocarcinoma: Experimental and Clinical Perspectives

2018 ◽  
Vol 19 (7) ◽  
pp. 2033 ◽  
Author(s):  
Jolanta Majka ◽  
Mateusz Wierdak ◽  
Iwona Brzozowska ◽  
Marcin Magierowski ◽  
Aleksandra Szlachcic ◽  
...  
Keyword(s):  
Barrett’S Esophagus ◽  
Reflux Esophagitis ◽  
Barrett's Esophagus ◽  
Free Radical Scavenger ◽  
The Body ◽  
Oxidative Enzymes ◽  
Esophageal Injury ◽  
Radical Scavenger ◽  
Target Cells ◽  
Liver Uptake

Melatonin is a tryptophan-derived molecule with pleiotropic activities which is produced in all living organisms. This “sleep” hormone is a free radical scavenger, which activates several anti-oxidative enzymes and mechanisms. Melatonin, a highly lipophilic hormone, can reach body target cells rapidly, acting as the circadian signal to alter numerous physiological functions in the body. This indoleamine can protect the organs against a variety of damaging agents via multiple signaling. This review focused on the role played by melatonin in the mechanism of esophagoprotection, starting with its short-term protection against acute reflux esophagitis and then investigating the long-term prevention of chronic inflammation that leads to gastroesophageal reflux disease (GERD) and Barrett’s esophagus. Since both of these condition are also identified as major risk factors for esophageal carcinoma, we provide some experimental and clinical evidence that supplementation therapy with melatonin could be useful in esophageal injury by protecting various animal models and patients with GERD from erosions, Barrett’s esophagus and neoplasia. The physiological aspects of the synthesis and release of this indoleamine in the gut, including its release into portal circulation and liver uptake is examined. The beneficial influence of melatonin in preventing esophageal injury from acid-pepsin and acid-pepsin-bile exposure in animals as well as the usefulness of melatonin and its precursor, L-tryptophan in prophylactic and supplementary therapy against esophageal disorders in humans, are also discussed.

scholarly journals Day and Night GSH and MDA Levels in Healthy Adults and Effects of Different Doses of Melatonin on These Parameters

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Shilpa Chakravarty ◽  
Syed Ibrahim Rizvi
Keyword(s):  
Oxidative Stress ◽  
Membrane Lipid ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Secretory Product ◽  
Therapeutic Implications ◽  
Antioxidative Function ◽  
Reliable Marker

The pineal secretory product melatonin (chemically, N-acetyl-5-methoxytryptamine) acts as an effective antioxidant and free-radical scavenger and plays an important role in several physiological functions such as sleep induction, immunomodulation, cardiovascular protection, thermoregulation, neuroprotection, tumor-suppression and oncostasis. Membrane lipid-peroxidation in terms of malondialdehyde (MDA) and intracellular glutathione (GSH) is considered to be a reliable marker of oxidative stress. The present work was undertaken to study the modulating effect of melatonin on MDA and GSH in human erythrocytes during day and night. Our observation shows the modulation of these two biomarkers by melatonin, and this may have important therapeutic implications.In vitrodose-dependent effect of melatonin also showed variation during day and night. We explain our observations on the basis of melatonin's antioxidative function and its effect on the fluidity of plasma membrane of red blood cells. Rhythmic modulation of MDA and GSH contents emphasized the role of melatonin as an antioxidant and its function against oxidative stress.

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