scholarly journals Phytoene Accumulation in the Novel Microalga Chlorococcum sp. Using the Pigment Synthesis Inhibitor Fluridone

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 187 ◽  
Author(s):  
Kelly Laje ◽  
Mark Seger ◽  
Barry Dungan ◽  
Peter Cooke ◽  
Juergen Polle ◽  
...  
Keyword(s):  
Antioxidant Properties ◽  
Phytoene Desaturase ◽  
Oxygen Species ◽  
The Novel ◽  
Synthesis Inhibitor ◽  
Pigment Synthesis ◽  
Pharmaceutical Applications ◽  
Cell Tissue ◽  
Secondary Carotenoids ◽  
Absorption Characteristics

Carotenoids are lipophilic pigments found in plants and algae, as well as some bacteria, archaea, and fungi that serve two functions—(1) as light harvesting molecules—primary carotenoids, and (2) as antioxidants, acting against reactive oxygen species–secondary carotenoids. Because of their strong antioxidant properties, they are also valuable for the development of anti-aging and photo-protective cosmetic applications. Of particular interest is the carotenoid phytoene, for its colorless and UV absorption characteristics. In this study, we targeted a reduction of phytoene desaturase (PDS) activity with the pigment-inhibiting herbicide 1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]pyridin-4-one (fluridone), which leads to the over-accumulation of phytoene in the recently characterized microalgal strain Chlorococcum sp. (UTEX B 3056). After post-incubation with fluridone, phytoene levels were measured at ~33 ug/mg cell tissue, as opposed to non-detectable levels in control cultures. Hence, the novel microalga Chlorococcum sp. is a viable candidate for the production of the high-value carotenoid phytoene and subsequent applications in cosmeceuticals, as well as more obvious nutraceutical and pharmaceutical applications.

Amentoflavone: A Bifunctional Metal Chelator that Controls the Formation of Neurotoxic Soluble Aβ42 Oligomers

2020 ◽  
Author(s):  
Liang Sun ◽  
Anuj K. Sharma ◽  
Byung-Hee Han ◽  
Liviu M. Mirica
Keyword(s):  
Reactive Oxygen Species ◽  
Metal Ions ◽  
Antioxidant Properties ◽  
Reactive Oxygen ◽  
Amyloid Plaques ◽  
Transition Metal Ions ◽  
Oxygen Species ◽  
High Affinity ◽  
Amyloid Aβ ◽  
Β Amyloid

<p>Alzheimer's disease (AD) is the most common neurodegenerative disorder, yet the cause and progression of this disorder are not completely understood. While the main hallmark of AD is the deposition of amyloid plaques consisting of the β-amyloid (Aβ) peptide, transition metal ions are also known to play a significant role in disease pathology by expediting the formation of neurotoxic soluble β-amyloid (Aβ) oligomers, reactive oxygen species (ROS), and oxidative stress. Thus, bifunctional metal chelators that can control these deleterious properties are highly desirable. Herein, we show that amentoflavone (AMF) – a natural biflavonoid compound, exhibits good metal-chelating properties, especially for chelating Cu<sup>2+</sup> with very high affinity (pCu<sub>7.4</sub> = 10.44). In addition, AMF binds to Aβ fibrils with a high affinity (<i>K<sub>i</sub></i> = 287 ± 20 nM) – as revealed by a competition thioflavin T (ThT) assay, and specifically labels the amyloid plaques <i>ex vivo</i> in the brain sections of transgenic AD mice – as confirmed via immunostaining with an Ab antibody. The effect of AMF on Aβ<sub>42</sub> aggregation and disaggregation of Aβ<sub>42</sub> fibrils was also investigated, to reveal that AMF can control the formation of neurotoxic soluble Aβ<sub>42</sub> oligomers, both in absence and presence of metal ions, and as confirmed via cell toxicity studies. Furthermore, an ascorbate consumption assay shows that AMF exhibits potent antioxidant properties and can chelate Cu<sup>2+</sup> and significantly diminish the Cu<sup>2+</sup>-ascorbate redox cycling and reactive oxygen species (ROS) formation. Overall, these studies strongly suggest that AMF acts as a bifunctional chelator that can interact with various Aβ aggregates and reduce their neurotoxicity, can also bind Cu<sup>2+</sup> and mediate its deleterious redox properties, and thus AMF has the potential to be a lead compound for further therapeutic agent development for AD. </p>

scholarly journals Evaluation of Toxicity and Antioxidant Property of Cassia fistula Stem Bark Extracts in Zebrafish

2020 ◽  
Vol 10 (03) ◽  
pp. 109-115
Author(s):  
Shreya Udaya ◽  
Nishith Babu ◽  
Dechamma Pandyanda Nanjappa ◽  
Krithika Kalladka ◽  
Gunimala Chakraborty ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Antioxidant Properties ◽  
Ethanol Extract ◽  
Antioxidant Property ◽  
Stem Bark ◽  
Oxygen Species ◽  
Cassia Fistula ◽  
Potential Applications ◽  
Ethanol Extracts ◽  
Stress Models

Abstract Objective This study was aimed at evaluating the toxicity and the antioxidant property of Cassia fistula stem bark extracts in zebrafish. Materials and Methods Crude aqueous and ethanol extracts of C. fistula stem bark were obtained following a standard solvent-based extraction method. The toxicity of these extracts on zebrafish embryonic development was determined and the LC50 values were calculated. Finally, the antioxidant property of C. fistula stem bark extracts was determined in arsenic-induced oxidative stress models of zebrafish. Results The aqueous extract of C. fistula stem bark showed a slightly larger LC50 value (213.6 ppm) compared with the ethanol extract (LC50 = 63.5 ppm), suggesting a lower toxicity of the aqueous extract. A significant reduction of reactive oxygen species (ROS) signal was observed in arsenic-exposed embryos treated with the aqueous extract, but not the ethanol extract, indicating that the antioxidant activity is present only in the aqueous extract of C. fistula stem bark. Conclusion Identification of antioxidants from natural sources is desirable because of increasing safety concerns associated with synthetic antioxidants. This study demonstrated that aqueous extract from C. fistula stem bark possesses antioxidant properties, which can be further characterized for mechanism of action and potential applications.

scholarly journals How to express the antioxidant properties of substances properly?

2021 ◽  
Author(s):  
Małgorzata Olszowy-Tomczyk
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Literature Review ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Reactive Oxygen ◽  
The Body ◽  
Universal Method ◽  
Oxygen Species ◽  
Good Tool

AbstractOxidative stress, associated with an imbalance between the oxidants (reactive oxygen species) and the antioxidants in the body, contributes to the development of many diseases. The body’s fight against reactive oxygen species is supported by antioxidants. Nowadays, there are too many analytical methods, but there is no one universal technique for assessing antioxidant properties. Moreover, the applied different ways of expressing the results lead to their incompatibility and unreasonable interpretation. The paper is a literature review concerning the most frequent ways of antioxidant activities expression and for an easy and universal method of the obtained results discussion. This paper is an attempt to point out their disadvantages and advantages. The manuscript can support the searching interpretation of the obtained results which will be a good tool for the development of a number of fields, especially medicine what can help in the future detection and treatment of many serious diseases. Graphic abstract

scholarly journals Novel Antioxidant Properties of Doxycycline

2018 ◽  
Vol 19 (12) ◽  
pp. 4078 ◽  
Author(s):  
Dahn Clemens ◽  
Michael Duryee ◽  
Cleofes Sarmiento ◽  
Andrew Chiou ◽  
Jacob McGowan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Chronic Inflammation ◽  
Antioxidant Properties ◽  
Antibacterial Properties ◽  
Reactive Oxygen ◽  
Protein Adducts ◽  
Oxygen Species ◽  
Free System

Doxycycline (DOX), a derivative of tetracycline, is a broad-spectrum antibiotic that exhibits a number of therapeutic activities in addition to its antibacterial properties. For example, DOX has been used in the management of a number of diseases characterized by chronic inflammation. One potential mechanism by which DOX inhibits the progression of these diseases is by reducing oxidative stress, thereby inhibiting subsequent lipid peroxidation and inflammatory responses. Herein, we tested the hypothesis that DOX directly scavenges reactive oxygen species (ROS) and inhibits the formation of redox-mediated malondialdehyde-acetaldehyde (MAA) protein adducts. Using a cell-free system, we demonstrated that DOX scavenged reactive oxygen species (ROS) produced during the formation of MAA-adducts and inhibits the formation of MAA-protein adducts. To determine whether DOX scavenges specific ROS, we examined the ability of DOX to directly scavenge superoxide and hydrogen peroxide. Using electron paramagnetic resonance (EPR) spectroscopy, we found that DOX directly scavenged superoxide, but not hydrogen peroxide. Additionally, we found that DOX inhibits MAA-induced activation of Nrf2, a redox-sensitive transcription factor. Together, these findings demonstrate the under-recognized direct antioxidant property of DOX that may help to explain its therapeutic potential in the treatment of conditions characterized by chronic inflammation and increased oxidative stress.

scholarly journals The Antioxidant Role of Soy and Soy Foods in Human Health

Antioxidants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 635
Author(s):  
Gianluca Rizzo
Keyword(s):  
Clinical Trials ◽  
Scientific Evidence ◽  
Antioxidant Properties ◽  
Oxygen Species ◽  
Healthy Foods ◽  
Bioactive Substances ◽  
Soy Foods ◽  
Antioxidant Mechanisms ◽  
Final Synthesis

Oxidative stress seems to play a role in many chronic diseases, such as cardiovascular diseases, diabetes, and some cancers. Research is always looking for effective approaches in the prevention and treatment of these pathologies with safe strategies. Given the central role of nutrition, the identification of beneficial healthy foods can be the best key to having a safe and at the same time effective approach. Soy has always aroused great scientific interest but often this attention is galvanized by the interaction with estrogen receptors and related consequences on health. However, soy, soy foods, and soy bioactive substances seem to have antioxidant properties, suggesting their role in quenching reactive oxygen species, although it was frequently mentioned but not studied in depth. The purpose of this review is to summarize the scientific evidence of the antioxidant properties of soy by identifying the human clinical trials available in the literature. A total of 58 manuscripts were individuated through the literature search for the final synthesis. Soy bioactive substances involved in redox processes appear to be multiple and their use seems promising. Other larger clinical trials with adequate standardization and adequate choice of biomarkers will fill the gap currently existing on the suggestive role of soy in antioxidant mechanisms.

scholarly journals Revisiting the Oxidation of Flavonoids: Loss, Conservation or Enhancement of Their Antioxidant Properties

Antioxidants ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 133
Author(s):  
Hernan Speisky ◽  
Fereidoon Shahidi ◽  
Adriano Costa de Camargo ◽  
Jocelyn Fuentes
Keyword(s):  
Antioxidant Capacity ◽  
Antioxidant Properties ◽  
Oxidative Modification ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
High Susceptibility ◽  
Comprehensive Description ◽  
Health Promoting ◽  
Endogenous Antioxidant ◽  
Electrophilic Character

Flavonoids display a broad range of health-promoting bioactivities. Among these, their capacity to act as antioxidants has remained most prominent. The canonical reactive oxygen species (ROS)-scavenging mode of the antioxidant action of flavonoids relies on the high susceptibility of their phenolic moieties to undergo oxidation. As a consequence, upon reaction with ROS, the antioxidant capacity of flavonoids is severely compromised. Other phenol-compromising reactions, such as those involved in the biotransformation of flavonoids, can also markedly affect their antioxidant properties. In recent years, however, increasing evidence has indicated that, at least for some flavonoids, the oxidation of such residues can in fact markedly enhance their original antioxidant properties. In such apparent paradoxical cases, the antioxidant activity arises from the pro-oxidant and/or electrophilic character of some of their oxidation-derived metabolites and is exerted by activating the Nrf2–Keap1 pathway, which upregulates the cell’s endogenous antioxidant capacity, and/or, by preventing the activation of the pro-oxidant and pro-inflammatory NF-κB pathway. This review focuses on the effects that the oxidative and/or non-oxidative modification of the phenolic groups of flavonoids may have on the ability of the resulting metabolites to promote direct and/or indirect antioxidant actions. Considering the case of a metabolite resulting from the oxidation of quercetin, we offer a comprehensive description of the evidence that increasingly supports the concept that, in the case of certain flavonoids, the oxidation of phenolics emerges as a mechanism that markedly amplifies their original antioxidant properties. An overlooked topic of great phytomedicine potential is thus unraveled.

Reactive Oxygen Species Activity and Antioxidant Properties ofFusariumInfected Bananas

2017 ◽  
Vol 165 (4) ◽  
pp. 213-222 ◽  
Author(s):  
Kelvin Kiran Anthony ◽  
Dominic Soloman George ◽  
Hasvinder Kaur Baldev Singh ◽  
Shi Ming Fung ◽  
Vicknesha Santhirasegaram ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Antioxidant Properties ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Species Activity

Degradation of natural toxins by phthalocyanines–example of cyanobacterial toxin, microcystin

2010 ◽  
Vol 62 (2) ◽  
pp. 273-278 ◽  
Author(s):  
Daniel Jančula ◽  
Lucie Bláhová ◽  
Marie Karásková ◽  
Blahoslav Maršálek
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Visible Light ◽  
Singlet Oxygen ◽  
Oxygen Species ◽  
Cyanobacterial Toxin ◽  
Natural Toxins ◽  
Peptide Toxins ◽  
Near Future ◽  
Absorption Characteristics

Phthalocyanines (Pcs) are promising photosensitizers for use in various branches of science and industry. In the presence of visible light and diatomic oxygen, phthalocyanines can react to produce singlet oxygen, a member of reactive oxygen species able to damage different molecules and tissues. The aim of this study was to investigate the ability of phthalocyanines to degrade natural toxins in the presence of visible light. As the representative of hardly degradable toxins, a group of cyanobacterial peptide toxins—microcystin-LR—was chosen for this study. According to our results, phthalocyanines are able to degrade 61,5% of microcystins within a 48-hour incubation (38% of microcystins was degraded after 24 h and 24% after 12 h of incubation). Although other oxidants like hydrogen peroxide or ozone are able to degrade microcystins within several hours, we assume that by optimizing the spectrum emitted by light source and by changing the absorption characteristics of Pcs, microcystins degradation by phthalocyanines could be more effective in the near future.

Curcuma longa extract reduces the risk of oxidative stress during intense physical exertion

2020 ◽  
pp. 43-49
Author(s):  
A. A. Khisamova ◽  
O. A. Gizinger
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Literature Review ◽  
Curcuma Longa ◽  
Antioxidant Properties ◽  
Physical Exertion ◽  
The Body ◽  
Irreversible Processes ◽  
Oxygen Species ◽  
Wide Range

Increased physical exertion is a catalyst for oxidative stress and the production of reactive oxygen species, which entails irreversible processes in the body, leading to chronic diseases and disability. This article contains a literature review of studies that prove the effect of the antioxidant properties of Curcuma longa on cells under oxidative stress. To search for data, a wide range of literature and databases was explored: Pubmed, Google.Scholar, and Embase.

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