ARTICLE | doi:10.20944/preprints202208.0210.v1
Subject: Life Sciences, Biochemistry Keywords: hydroxocobalamin; cyanocobalamin; thiolatocobalamins; thiol oxidation; ROS production; cytotoxicity
Online: 11 August 2022 (06:17:50 CEST)
Cobalamin is an essential nutrient required for the normal functioning of cells. Its deficiency can lead to various pathological states. Hydroxocobalamin (HOCbl) and cyanocobalamin (CNCbl) are the forms of vitamin B12 that are most commonly used for supplementation. There is substantial evidence indicating that cobalamins can both suppress and promote oxidative stress; however, the mechanisms underlying these effects are poorly understood. Here, it was shown that the oxidation of thiols catalyzed by HOCbl and CNCbl is accompanied by ROS production and induces, under certain conditions, oxidative stress and cell death. The form of vitamin B12 and the structure of thiol play a decisive role in these processes. It was found that the mechanisms and kinetics of thiol oxidation catalyzed by HOCbl and CNCbl differ substantially. It was discussed how these differences may explain different levels of ROS production and cytotoxicity induced by combinations of thiols with HOCbl and CNCbl. On the whole, the data obtained provide a new insight into the redox processes in which cobalamins are involved and might be helpful in developing new approaches to the treatment of some cobalamin-responsive disorders in which oxidative stress is an important component. In addition, these data may be useful for a better understanding of mechanisms underlying induction of different types of death of cancer cells and in a search for new targets for anticancer therapy.
ARTICLE | doi:10.20944/preprints201610.0101.v1
Subject: Life Sciences, Immunology Keywords: reactive oxygen species (ROS); asthma; montelukast; long-acting β2 agonist (LABA); corticosteroid; monocyte
Online: 24 October 2016 (05:50:30 CEST)
Asthma is a chronic inflammatory airway disease induced by many environmental factors. The inhalation of allergens and pollutants promote the reactive oxygen species (ROS) production leading to airway inflammation, hyper-responsiveness and remodeling in allergic asthma. The effects of asthma medications on ROS production are unclear. The present study investigated the anti-ROS effects of current asthma medications including inhaled corticosteroid (ICS; budesonide and fluticasone), leukotriene receptor antagonist (LTRA; montelukast), long acting β2 agonists (LABAs; salmeterol and formoterol) and a new extra-LABA (indacaterol). The human monocyte cell line THP-1 cells were pre-treated with different concentrations of the asthma medications at different time-points after hydrogen peroxide (H2O2) stimulation. H2O2 production was measured with DCFH-DA by flow cytometry. Montelukast, fluticasone and salmeterol suppressed H2O2-induced ROS production. Indacaterol enhanced H2O2-induced ROS production. Budesonide and formoterol alone had no anti-ROS effects, but the combination of these two drugs significantly suppressed H2O2-induced ROS production. Different asthma medications have different anti-ROS effects on monocytes. The combination therapy with LABA and ICS seemed not be the only choice for asthma control. Montelukast may be also a good supplemental treatment for the poorly-controlled asthma because of its powerful anti-ROS effects. Our findings provide a novel therapeutic view in asthma.
REVIEW | doi:10.20944/preprints202101.0606.v1
Subject: Chemistry, Analytical Chemistry Keywords: ROS; sources of ROS; oxidative stress; ROS and cancer
Online: 29 January 2021 (09:01:24 CET)
When the antioxidants in our immune system cannot neutralize or convert Reactive oxygen species into safe molecules at the rate at which it is produced then this imbalance is termed as “oxidative stress”. It is related with a wide array of diseases that includes cancer, diabetes, cardiovascular diseases, hypertension etc. These ROS species however are utmost essential for the proper functioning of human body which are produced as a consequence of partial oxidation of cellular metabolism performing essential functions such as protein phosphorylation, activation of several transcriptional factors, apoptosis, immunity, and differentiation. The sources by which these are produced can be broadly classified are intrinsic and extrinsic sources. There are variety of natural antioxidant enzymes of human body that combat against this oxidative stress. The extrinsic sources of ROS include the use of natural plants, extracted flavonoids and vitamins. In this review we will briefly explain how the sources of ROS, its essential function in human body, its elevation and associated damage to organs and effect on various diseases, and a hope of finding a way of how this oxidative stress can be exploited for therapeutic potential.
REVIEW | doi:10.20944/preprints201703.0195.v1
Subject: Medicine & Pharmacology, Obstetrics & Gynaecology Keywords: melatonin; antioxidants; RNS; ROS; embryo development; DNA integrity; DNA oxidation; gene expression
Online: 27 March 2017 (10:04:31 CEST)
Oxidative and nitrosative stress are a common problem when manipulating gametes in vitro. In vitro development in mammalian embryos is highly affected by culture conditions, especially by reactive oxygen species (ROS) and reactive nitrogen species (RNS), because its absence or over production causes embryo arrest and changes in gene expression. Melatonin in gamete co-incubation during IVF has deleterious or positive effects depending on the concentration used in culture medium, demonstrating the delicate balance that must exist between antioxidant and pro-oxidant activity. Further research is needed to better understand the possible impact of melatonin on the different IVP steps in domestic animals, especially in seasonal breeds where this neuro-hormone system highly regulates its reproduction physiology.
ARTICLE | doi:10.20944/preprints202201.0149.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: Mussel; spermatozoa; millimeter waves; ROS
Online: 11 January 2022 (15:45:04 CET)
Recently, a rising use of wireless internet technologies has been demonstrated. The devices which use these technologies emit a considerable amount of electromagnetic radiation (EMFs) which could interact with the male reproductive system. The aim of this study was to investigate in vitro influence of electromagnetic fields a 27 GHz on sperm quality in Mytilus galloprovincialis. The experiments were conducted with a no commercial high gain pyramidal horn antenna. Sperm samples, taken from sexually mature males of M. galloprovincialis, were placed in seawater. Once evaluated the number and quality of spermatozoa, sperm cells were exposed to electromagnetic fields. The effect of exposure was evaluated after 10, 20, 30 and 40 minutes with light microscope and using Eosin test. All the samples were performed in triplicate and statistical analysis was carried out by one-way ANOVA test. A significative decrease (30%) in sperm motility was ob-served after 10 minutes of exposure and after 30 minutes all sperms were immobile and not vital. The measurement of the Oxidation Reduction Potential (sORP), which evaluates the oxidative damage on spermatozoa, shows how the exposure to 27 GHz has increased the oxidant amount compared to the control groups. This study provides useful data on potential ecological impact of the EMFs on aquatic animals, that currently are poor investigated.
REVIEW | doi:10.20944/preprints202102.0107.v1
Online: 3 February 2021 (10:09:39 CET)
Pancreatic cancer is a fatal disease with mortality rate of 5% and a with a limited survival rate of 5 years. Despite of the extensive efforts that has been made to cure the disease it still has been considered as ‘undruggable’. It is characterized by epithelial to dense stromal tumor formation however due to lack of diagnosis options and treatment test available to detect the disease to the point at which resection of the tumor is possible, it makes it the fourth leading cause of cancer related death. The unavailable information regarding the early detection of biological markers along with the increased invasive tumor, the inherit chemoresistance against medication radiation and chemotherapy stubbornly fail the therapeutic options available. These associated problems made the scientists to reevaluate the approaches that are currently in practice and take a step back to fully understand the basic biological pathways that are involved in the pancreatic cancer, the heterogeneity of the tumor itself along with expression and a number of mutations that are observed at different locations. Clinical trial along with new approaches are nowadays focus of research to treat this tumor. The review paper describes the basic cellular pathways involved in pancreatic cancer, the gene mutations and their expression having effect on the pathology of the diseases along with treatment options that are available to treat the tumor. These efforts will help with the expansion of our knowledge to undergo the clinical trial and the synthesis of novel medicines for the prognosis of the disease.
ARTICLE | doi:10.20944/preprints201812.0036.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: ROS; histochemical; superoxide; hydrogen peroxide
Online: 3 December 2018 (16:17:03 CET)
The present protocol described staining protocol for Reactive Oxygen Species (ROS) in aromatic crop grown under nutrient stress through DAB and NBT histochemical method. Spearmint (Mentha spicata) were grown under manganese and salt toxicity stresses and after 10 and 20 days of the stress treatments, plants showed stunted growth. The morphological characteristics of leaves under stresses were observed. Manganese toxicity and salt stress induced the production of ROS. Accumulation of hydrogen peroxide was characterised as brown spots from the DAB polymerisation which were emerged and clearly observed in leaves from plant grown under 2.5 and 5 mM concentrations of manganese as well as 300 mM concentration of salt. Furthermore, accumulation of superoxide anion was characterised as blue pigments based upon the ability of cells to reduce NBT. Spearmint leaves showed the distribution of the blue pigment which was obviously observed under the 5 mM of manganese and 300 mM of salt. DAB and NBT staining method can be the rapid method to characterise ROS accumulation in plant cell under the abiotic stresses.
ARTICLE | doi:10.20944/preprints201807.0066.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: oridonin; radiation; sensitization; ROS; apoptosis
Online: 4 July 2018 (10:19:51 CEST)
Although many attempts have been made to improve the efficacy of radiotherapy to treat cancer, radiation resistance is still an obstacle in lung cancer treatment. Oridonin is a natural compound with promising antitumor efficacy that can trigger cancer cell death; however, its direct cellular targets, efficacy as a radiosensitizer, and underlying mechanisms of activity remain unclear. Herein, we report that oridonin exhibits additive cytotoxic and antitumor activity with radiation using H460 non-small cell lung cancer cell lines. We assessed the radiosensitizing effect of oridonin by MTT, clonogenic, reactive oxygen species (ROS) production, DNA damage, and apoptosis assays. In vitro, oridonin enhanced the radiation-induced inhibition of cell growth and clonogenic survival. Oridonin also facilitated radiation-induced ROS production and DNA damage and enhanced apoptotic cell death. In vivo, the combination of oridonin and radiation effectively inhibited H460 xenograft tumor growth, with higher caspase-3 activation and H2A histone family member X (H2AX) phosphorylation compared with that of radiation alone. Our findings suggest that oridonin possesses a novel mechanism to enhance radiation therapeutic responses by increasing DNA damage and apoptosis. In conclusion, oridonin may be a novel small molecule to improve radiotherapy in non-small cell lung cancer.
ARTICLE | doi:10.20944/preprints201805.0064.v1
Online: 3 May 2018 (09:38:17 CEST)
Under abiotic stress conditions, arbuscular mycorrhizal (AM) fungi help plants by improving nutrient and water uptake. Finger millet is an arid crop having soils with poor water holding capacity. Therefore, it is difficult for the plants to obtain water and mineral nutrients from the soil to sustain life. To understand the role of mycorrhizal symbiosis in water and mineral up-take from the soil, we studied the role of Rhizophagus intraradices colonization and its beneficial role for drought stress tolerance in finger millet seedling. Under severe drought stress condition, AM inoculation led to the significant increase in plant growth (7%), phosphorus, and chlorophyll content (29%). Also, the level of osmolytes including proline and soluble sugars were found in higher quantities in AM inoculated seedlings under drought stress. Under water stress, the lipid peroxidation in leaves of mycorrhized seedlings was reduced by 29%. The flavonoid content of roots in AM colonized seedlings was found 16% higher compared to the control, whereas the leaves were accumulated more phenol. Compared to the control, ascorbate level was found to be 25% higher in leaf tissue of AM inoculated seedlings. Moreover, glutathione (GSH) level was increased in mycorrhiza inoculated seedlings with a maximum increment of 182% under severe stress. The results demonstrated that AM provided drought tolerance to the finger millet seedlings through a stronger root system, greater photosynthetic efficiency, a more efficient antioxidant system and improved osmoregulation.
REVIEW | doi:10.20944/preprints202104.0637.v1
Subject: Biology, Anatomy & Morphology Keywords: metal toxicity, phytomelatonin, heavy metals, ROS, NO
Online: 23 April 2021 (12:36:12 CEST)
Metal toxicity in soils, along with water runoff, are increasing environmental problems that affect agriculture directly and, in turn, human health. In light of finding a suitable and urgent solution, research on plant treatments with specific compounds that can help mitigate these effects has increased, and thus the exogenous application of melatonin (MET) and its role in alleviating the negative effects of metal toxicity in plants, have become more important in the last few years. MET is an important plant-related response molecule involved in growth, development, and reproduction, and in the induction of different stress-related key factors in plants. It has been shown that MET plays a protective role against the toxic effects induced by different metals (Pb, Cd, Cu, Zn, B, Al, V, Ni, La, As, and Cr) by regulating both the enzymatic and non-enzymatic antioxidant plant defense systems. In addition, MET interacts with many other signaling molecules, such as reactive oxygen species (ROS) and nitric oxide (NO), and participates in a wide variety of physiological reactions. Furthermore, MET treatment enhances osmoregulation and photosynthetic efficiency and increases the concentration of other important antioxidants such as phenolic compounds, flavonoids, polyamines (PAs), and carotenoid compounds. Some recent studies have shown that MET appeared to be involved in the regulation of metal transport in plants, and lastly, various studies have confirmed that MET significantly upregulated stress tolerance-related genes. Despite all the knowledge acquired over the years, there is still more to know about how MET is involved in the metal toxicity tolerance of plants.
REVIEW | doi:10.20944/preprints201912.0258.v1
Online: 19 December 2019 (11:12:08 CET)
Hypoxia is the main survival challenge that human beings encounter in high altitudes, it is also the leading cause of Acute Mountain Sickness (AMS). Studies have shown that hypoxia induces a large number of reactive oxygen species (ROS) in AMS patients, and the surge of ROS leads to the reduction of oxygen delivery capacity of erythrocyte, senescence and inflammatory impairment of erythrocyte and vascular endothelial cells to a certain extent. Through depicting a target-pathway network, our study indicates that Compound Danshen Dropping Pills (CDDP), which is one of the best-known traditional Chinese medicine used for the treatment of myocardial ischemic diseases, can improve red blood cell oxygen delivery capacity in AMS patients, alleviate tissue and organ damage, relieve a series of clinical symptoms caused by hypoxia through ROS clearance and related mechanisms. We further elucidate the active ingredients of CDDP targeting ROS related pathway by target-ingredient correspondence analysis. Tanshinone IIA, catechol and some other compounds of CDDP were identified to have certain targeting effect on ROS and ROS dependent pathways. This study provides new understandings of CDDP in clinical application on AMS.
ARTICLE | doi:10.20944/preprints201907.0035.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: ROS; SLAM; RGB-D sensors; experimental analysis
Online: 2 July 2019 (08:43:16 CEST)
Since it was proposed, the Robot Operating System (ROS) has fostered solutions for various problems in robotics in the form of ROS packages. One of these problems is Simultaneous Localization and Mapping (SLAM), a problem solved by computing the robot pose and a map of its environment of operation at the same time. The increasingly availability of robot kits ready to be programmed and also of RGB-D sensors often pose the question of which SLAM package should be used given the application requirements. When the SLAM subsystem must deliver estimates for robot navigation, as is the case of applications involving autonomous navigation, this question is even more relevant. This work introduces an experimental analysis of GMapping and RTAB-Map, two ROS compatible SLAM packages, regarding their SLAM accuracy, quality of produced maps and use of produced maps in navigation tasks. Our analysis aims ground robots equipped with RGB-D sensors for indoor environments and is supported by experiments conducted on datasets from simulation, benchmarks and from our own robot.
REVIEW | doi:10.20944/preprints201909.0344.v1
Subject: Medicine & Pharmacology, Veterinary Medicine Keywords: horses; spermatozoa; ROS; oxidative stress; redox regulation; equine
Online: 30 September 2019 (08:06:46 CEST)
Redox regulation and oxidative stress have become areas of major interest in spermatology. Alteration of redox homeostasis is recognized as a significant cause of male factor infertility and is behind the damage that spermatozoa experience after freezing and thawing or conservation in a liquid state. While for a long time, oxidative stress was just considered an overproduction of ROS, nowadays it is considered as a consequence of redox deregulation. Many essential aspects of spermatozoa functionality are redox regulated, with reversible oxidation of thiols in cysteine residues of key proteins acting as an “on-off” switch controlling spermatic function. However, if deregulation occurs, these residues may experience irreversible oxidation and oxidative stress leading to spermatic malfunction and ultimately death. Stallion spermatozoa are “professional producers” of ROS due to their intense mitochondrial activity, and thus sophisticated systems to control redox homeostasis are also characteristic of this species. As a result, combined with the fact that embryos can easily be collected in this species, horses are a good model for the study of redox biology in the spermatozoa and its impact on the embryo.
REVIEW | doi:10.20944/preprints202205.0279.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Melatonin; NO; ROS; abiotic stress; NOmela; H2S; NRS; PTMs
Online: 20 May 2022 (13:35:00 CEST)
Melatonin (MEL), a ubiquitous indolamine, is a molecule whose regulatory role in plan metabolism has gained interest in the last decades. Likewise, nitric oxide (NO), a gasotransmitter, can also affect plant molecular pathways due to its function as a signalling molecule. Both MEL and NO can interact at multiple levels under abiotic stress, starting by their own biosynthetic pathways and inducing a particular signalling response in plants. This review summarizes the role of these molecules during plant development and fruit ripening, as well as their interactions. Due to the impact of climate change‐related abiotic stresses on agriculture, this review has also focused on their role in mediating abiotic stress tolerance and the mechanisms by which they operate, from upregulation of the whole antioxidant defence system to posttranductional modifications of important molecules. Their interactions and crosstalk with phytohormones and H2S is also discussed. Finally, we introduce NOmela, an emerging and very unknown molecule which seems to have a stronger potential than MEL and NO separately in mediating plant stress response.
ARTICLE | doi:10.20944/preprints202203.0175.v1
Subject: Biology, Other Keywords: Fluconazole; Itraconazole; ROS; mitochondrial activity; Trehalase; Trehalose; Candida parapsilosis
Online: 14 March 2022 (08:36:24 CET)
Central metabolic pathways may play a major role in the virulence of pathogenic fungi. Here, we have investigated the susceptibility of a Candida parapsilosis mutant deficient in trehalase activity (atc1Δ/ntc1Δ strain) to the azolic compounds Fluconazole and Itraconazole. A time-course exposure to Itraconazole but not Fluconazole induced a significant degree of cell-killing in mutant cells compared to the parental strain. Flow cytometry determinations indicated that Itraconazole was able to induce a marked production of endogenous ROS together with a simultaneous increase in membrane potential, these effects being irrelevant after Fluconazole addition. Furthermore, only Itraconazole induced a significant synthesis of endogenous trehalose. The recorded impaired capacity of mutant cells to produce structured biofilms was further increased in the presence of both azoles, with Itraconazole being more effective than Fluconazole. Our results in the opportunistic pathogen yeast C. parapsilosis reinforce the study of trehalose metabolism as an attractive therapeutic target and allow extending the hypothesis that the generation of internal oxidative stress may be a component of the antifungal action exerted by the compounds currently available in medical practice.
ARTICLE | doi:10.20944/preprints202111.0366.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: β-Apopicropodophyllin; Radiosensitizer; Topoisomerase inhibitor; ROS, Apoptosis; Colorectal cancer
Online: 19 November 2021 (14:54:40 CET)
β-apopicropodophyllin (APP), a derivative of podophyllotoxin (PPT), has been identified as a potential anti-cancer drug. This study tested whether APP acts as an an-ti-cancer drug and can sensitize colorectal cancer (CRC) cells to radiation treatment. APP had an anti-cancer effect against the CRC cell lines HCT116, and DLD-1, SW480 and COLO320DM with IC50 values of 7.88 nM, and 8.22 nM, 9.84 nM and 7.757 nM, respec-tively induction of DNA damage. Colonogenic and cell counting assays indicated that the combined treatment of APP and γ-ionizing radiation (IR) showed greater retardation of cell growth than either alone, suggesting that APP sensitizes CRC cells to IR. Annexin V-propidium iodide (PI) assays and immunoblot analysis showed that the combined treatment of APP and IR increased apoptosis in CRC cells compared with either APP or IR alone. Results obtained from the xenograft experiments also indicated that the combination of APP and IR enhanced apoptosis in in vivo animal model. Apoptosis induction by the combined treatment of APP and IR resulted from reactive oxygen species (ROS). Inhibition of ROS by N-acetylcysteine (NAC) restored cell viability and decreased the induction of apoptosis by APP and IR in CRC cells. Taken together, these results indicate that a combined treatment of APP and IR might promote apoptosis by inducing ROS in CRC cells.
REVIEW | doi:10.20944/preprints201808.0210.v1
Subject: Materials Science, Nanotechnology Keywords: microbubbles; nanobubbles; photoacoustic imaging; ultrasonic imaging; ROS; oxygen delivery
Online: 11 August 2018 (18:49:18 CEST)
Microbubbles and nanobubbles can be prepared using various shells, such as phospholipids, polymers, proteins, and surfactants. They are echogenic and can be used as contrast agents for ultrasonic and photoacoustic imaging. These bubbles can be engineered in various sizes as vehicles for gas and drug delivery applications with novel properties and flexible structures. Hypoxic areas in tumors develop owing to an imbalance of oxygen supply and demand. In tumors, hypoxic regions have shown more resistance to chemotherapy, radiotherapy, and photodynamic therapies. The efficacy of photodynamic therapy depends on the availability of oxygen in the tumor to generate reactive oxygen species. Micro/nanobubbles have been shown to reverse hypoxic conditions and increase tissue oxygen levels. This review summarizes the synthesis methods and shell compositions of micro/nanobubbles and methods deployed for oxygen delivery. In addition, the shortcomings and prospects of engineering micro/nanobubbles are discussed for their potential use in photodynamic therapy.
ARTICLE | doi:10.20944/preprints201805.0141.v1
Subject: Materials Science, Biomaterials Keywords: Caenorhabditis elegans; toxicity; gold nanoparticles; nanocomposites; Lectin Protein; ROS
Online: 9 May 2018 (08:11:49 CEST)
The lectin found in the tubers of the Winter Aconite (Eranthis hyemalis) plant (EHL) is a Type II Ribosome Inactivating Protein (RIP); type II RIPs have shown anti-cancer properties, and have great potential as therapeutic agents. Similarly, colloidal gold nanoparticles are successfully used in biomedical applications as gold nanoparticles can be functionalised with ligands with high affinity and specificity for target cells to create therapeutic and imaging agents. Herein we present the synthesis and characterization of gold nanoparticles conjugated with EHL. The aim was to establish the viability of the conjugate and perform a set of initial assays to establish whether the biological effect of EHL is altered by the conjugation. The biological assays were performed in Caenorhabditis elegans, a free living nematode commonly used for toxicological studies; previous work from some of the authors using first life stage (L1) nematodes has shown that EHL has a strong biocidal effect on C. elegans. Gold nanoparticles functionalised with EHL (AuNPs@EHL) were successfully synthesised by bioconjugation with citrate gold nanoparticles (AuNPs@Citrate); the conjugates were analysed by UV-Vis spectroscopy, Dynamic Light Scattering (DLS), Zeta Potential analysis and Transmission Electron Microscopy (TEM). Results indicate that an optimal functionalisation was achieved with the addition of 100 µL of EHL (concentration 1090 ± 40 µg/mL) over 5 mL of AuNPs (concentration [Au0] = 0.8 mM). Biological assays on the effect of AuNPs@EHL on C. elegans were performed, using first life stage (L1) and pre-adult stage (L4) nematodes. Citrate gold nanoparticles did not have any obvious effect on the nematodes. For L1 stage nematodes, the assays show that conjugation with gold nanoparticles reduced the biological effect of EHL on C. elegans. As lectin binding activity is essential for the natural protein to bind and allow entry to cells, conformational changes due to conjugation may have affected this binding affinity. For L4 stage nematodes, both EHL alone and AuNPs@EHL showed biological activity, and reproductive delays and reduced fecundity were observed in both cases. These assays indicate that EHL can be conjugated to gold nanoparticles and retain elements of biocidal activity.
REVIEW | doi:10.20944/preprints202012.0059.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Alzheimer’s disease; mitochondrial dysfunctions; phytochemicals; reactive oxygen species (ROS); autophagy
Online: 2 December 2020 (11:14:07 CET)
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by a decline in cognitive function with neuronal damage. Although the precise pathobiology of AD is still elusive, accumulating evidences suggest that mitochondrial dysfunction is one of the underlying causes of AD. Mutations of mitochondrial or nuclear DNA that encode mitochondrial constituents may cause mitochondrial dysfunctions. In particular, dysfunction of electron transport chain complexes along with interactions of mitochondrial pathological proteins are associated with mitochondrial dysfunctions in AD. Mitochondrial dysfunction causes an imbalance in reactive oxygen species, leading to oxidative stress (OS) and vice-versa. Neuroinflammation is another potential contributory factor to induce mitochondrial dysfunction. Phytochemicals or other natural compounds have the potential to scavenge oxygen free radicals and enhance cellular antioxidant defense system, and thereby protect against OS-mediated cellular damage. Phytochemicals can also modulate other cellular processes, including autophagy and mitochondrial biogenesis. Pharmacological intervention through neuroprotective phytochemicals can, therefore, be a potential strategy to combat mitochondrial dysfunctions as well as AD. This review focuses on the role of phytochemicals to mitigate mitochondrial dysfunction in the therapy of AD pathogenesis.
REVIEW | doi:10.20944/preprints202008.0291.v1
Subject: Life Sciences, Microbiology Keywords: Advanced Oxidation Process, Antibacterial resistance, Disinfection, Persistence, ROS, Stress response
Online: 13 August 2020 (06:15:17 CEST)
Different water treatment regiments are revealed to have potential in enriching antibiotic resistant bacteria (ARB). Advanced oxidation processes (AOPs) based disinfection techniques have been studied widely in the recent times due to their advantages over conventional treatment methods. However, bacterial response and adaptations against the hostile environments of AOPs is not clearly understood yet. Based on the existing knowledge on the ways in which bacteria surpass the antibiotic treatment, here we propose few important aspects of bacterial adaptation which could be true for AOPs as well since both antibiotics and AOPs generate reactive oxygen species (ROS) during their modes of action. We discuss the plausible role of ROS in the selection of ARB and bacterial heterogeneity as a strategy to bypass the lethal action of AOPs. Understanding bacterial adaptation during disinfection plays a vital role in devising strategies to outclass the bacterial survival. Hence, more importance should be given to such studies in the near future for the successful implementation of AOPs.
REVIEW | doi:10.20944/preprints202007.0182.v1
Subject: Earth Sciences, Atmospheric Science Keywords: Airborne aerosols; Reactive oxygen species (ROS); health effects; oxidative potential
Online: 9 July 2020 (11:29:50 CEST)
The mass concentration of particulate matter (PM) has been systematically used in epidemiological studies as exposure indicator, to relate airborne concentrations with a wide variety of human health effects, which can be hardly explained by using this single parameter. In fact, PM is a “particle cocktail” that includes a complex mixture of compounds with a wide range of sizes, chemical compositions and emission sources. Current research hypothesizes that many of the adverse health effects are derived from oxidative stress in biological systems caused by the deposition of PM into the lungs. This emerging hypothesis is called the oxidative stress paradigm. In this commentary article we analize how this new paradigm could help to answer the as-of-yet unanswered questions related to the mechanism of action of PM pollution on human health. Acellular oxidative potential (OP) assays have been emerged as a promising approach to quantify the PM potential to induce oxidative stress and to relate it with the chemical composition and size distribution of PM. Recent researches have shown that the OP is related to the presence of metals, organic carbon, polyaromatic hydrocarbons and quinones. However, the association between PM and particle-induced toxicity is still largely unknown. Therefore, additional research is needed to identify the specific PM characteristic(s), such as its specific size, emission source or chemical content, which contribute the most to its redox activity. Thus, the OP measurements provide information that allows us to evaluate and integrate the toxic potential of PM in a unique parameter, whose relationships with emission sources, size distribution and/or chemical composition should be faced in the near future.
ARTICLE | doi:10.20944/preprints201809.0253.v1
Subject: Biology, Animal Sciences & Zoology Keywords: diabetes mellitus; ROS; carbohydrate metabolism; antioxidants; chronic unpredictable environmental stress
Online: 14 September 2018 (05:20:37 CEST)
Chronic unpredictable environmental stress (CUES) may induce predisposition to diabetes mellitus. This study investigates the role of CUES on impaired homeostasis. Stressed group mice (n = 20) were exposed to CUES for 16 weeks. Weekly body weight, feed consumption, feed efficiency ratio, fasting blood glucose were monitored. Plasma HbA1c, plasma cortisol, plasma epinephrine and plasma insulin, serum lipids, antioxidants and carbohydrate metabolizing enzymes activity were assessed along with DNA damage and histopathological examination of liver, kidney, pancreas, spleen and skeletal muscles. Fasting blood glucose levels & HbA1c in the stressed were significantly higher compared to control (p < 0.001). Serum lipids were found insignificantly higher in stressed mice compared to control. Body weights of the stressed mice and feed efficiency ratio were found significant (p < 0.001). Plasma corticosterone, plasma epinephrine, HOMA-IR was found to be significantly higher in the stressed group (p < 0.001). Plasma insulin level was found to be significantly lower in the stressed group (p < 0.001). Significant changes were observed in antioxidants level, carbohydrate metabolizing enzymes activity, peripheral tissues and DNA integrity. CUES initiates pathogenesis of diabetes.
ARTICLE | doi:10.20944/preprints201703.0037.v1
Subject: Chemistry, Medicinal Chemistry Keywords: hypertension; 4-hydroxy-2-nonenal (4HNE); reactive oxygen species(ROS)
Online: 7 March 2017 (07:00:16 CET)
The oxidative stress is one of the main cause for cardiovascular diseases (like Hypertension) also one of the results of these diseases. This study involved 56 subjects matched ages and sex divided into two groups; 28 hypertensive subject and 28 healthy subject as control group. The following analysis was done: 4-Hydroxy-2-nonenal(4HNE) and albumin. The results show that there is a significant increase in (4HNE) between patients group and control group. The increase in 4HNE which is a product of lipid peroxidation is attributed to destruction in body cell caused by due to the increase in stress events. It has been concluded that is important nappy on ideal weight, because obesity considered main factors for heart disease and hardening of the arteries. The aim of this study was to investigate the relationship between of some oxidative stress markers and cardiovascular diseases.
REVIEW | doi:10.20944/preprints202102.0466.v1
Subject: Biology, Plant Sciences Keywords: Drought stress; Osmotic regulation; LEA protein; ROS; Signaling; Drought-responsive gene
Online: 22 February 2021 (12:38:05 CET)
With the global climate anomalies and the destruction of ecological balance, water shortage has become a serious ecological problem facing all mankind, and drought has become a key factor restricting the development of agricultural production. Therefore, it is essential to study the drought tolerance of crops. On the basis of previous studies, we reviewed the effects of drought stress on plant morphology and physiology, including the changes of external morphology and internal structure of root, stem and leaf, the effects of drought stress on osmotic regulation sub-stances, drought-induced proteins and active oxygen metabolism of plants. In this paper, the main drought stress signals and signal transduction pathways in plants are described, and the functional genes and regulatory genes related to drought stress are listed respectively. We summarize the above aspects in order to provide valuable background knowledge and theoret-ical basis for future agriculture and forestry breeding and cultivation.
REVIEW | doi:10.20944/preprints202012.0033.v1
Subject: Life Sciences, Biochemistry Keywords: reactive oxygen species (ROS), neuromelanin (NM), oxidative stress, neurodegeneration, immune response
Online: 1 December 2020 (15:02:04 CET)
Aging is associated with an increasing dysfunction of key brain homeostasis mechanisms and represents the main risk factor across most neurodegenerative disorders. However, the degree of dysregulation and the affectation of specific pathways set apart normal aging from neurodegenerative disorders. In particular, the neuronal metabolism of catecholaminergic neurotransmitters appears to be a specifically sensitive pathway that is affected in different neurodegenerations. In humans, catecholaminergic neurons are characterized by an age-related accumulation of neuromelanin (NM), rendering the soma of the neurons black. This intracellular NM appears to serve as a very efficient quencher for toxic molecules. However, when a neuron degenerates, NM is released together with its load (many undegraded cellular components, transition metals, lipids, antibiotics) contributing to initiate and worsen an eventual immune response, exacerbating the oxidative stress, ultimately leading to the neurodegenerative process. This review focuses on the analysis of the role of NM in normal aging and catecholaminergic metabolism due to its capability as a pro-oxidant and other harmful molecules, versus its involvement in oxidative stress and aberrant immune response, which it is highly dependent on NM saturation state and its extracellular release.
ARTICLE | doi:10.20944/preprints201805.0260.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: melatonin; UVB; HaCaT keratinocytes; collagen; ROS; Hedgehog; Cox-2; MMP-1
Online: 18 May 2018 (08:51:37 CEST)
Though melatonin is known to improve ultraviolet B (UVB)-induced oxidative damage and inflammatory conditions via blockade of nuclear factor (NF)-κB, interleukin (IL)-6, there is no report on anti-wrinkle effect of melatonin to date. Hence in the present study, anti-wrinkle mechanism of melatonin was elucidated in UVB treated HaCaT keratinocytes and hairless mice. Herein melatonin protected against a radical initiator tert-Butyl hydroperoxide (t-BOOH) induced reactive oxygen species (ROS) production, matrix metalloprotease 1 (MMP-1) and cytotoxicity in HaCaT keratinocytes. Also, melatonin suppressed the expression of sonic hedgehog (SHH) and GLI for hedgehog signaling, p-NF-kB, cyclooxygenase (COX-2), p-ERK for inflammatory responses in UVB treated HaCaT keratinocytes. Furthermore, melatonin protected skin from wrinkle formation, transdermal water loss in hairless mice irradiated by UVB for 8 weeks. Notably, melatonin prevented against epidermal thickness and dermal collagen degradation in UVB irradiated hairless mice by Hematoxylin & Eosin and Masson’s trichrome staining. Taken together, these findings suggest that melatonin reduces wrinkle formation via inhibition of ROS/SHH and inflammatory proteins such as NF-kB/COX-2/ERK/MMP1.
ARTICLE | doi:10.20944/preprints202111.0058.v1
Subject: Life Sciences, Microbiology Keywords: ozone; detrimental effect; pathogenic bacteria; antimicrobial resistance; ROS; Acinetobacter baumannii; Pseudomonas aeruginosa
Online: 3 November 2021 (07:55:57 CET)
(1) Background: Disinfection of medical devices designed for clinical use associated or not with the growing area of tissue engineering is an urgent need. However, traditional disinfection methods are not always suitable for some biomaterials, especially those sensitive to chemical, thermal, or radiation. Therefore, the objective of this study was to evaluate the minimal concentration of ozone gas (O3) necessary to control and kill a set of sensitive or multi-resistant Gram-positive and Gram-negative bacteria. The cell viability, membrane permeability, and the levels of reactive intracellular oxygen (ROS) species were also investigated; (2) Material and Methods: Four standard strains and a clinical MDR strain were exposed to low doses of ozone at different concentrations and times. Bacterial inactivation (cultivability, membrane damage) was investigated using colony counts, resazurin as a metabolic indicator, and propidium iodide (PI). A fluorescent probe (H2DCFDA) was used for the ROS analyses; (3) Results: No reduction in the count colony was detected after O3 exposure, compared to the control group. However, the cell viability of E. coli (30%), P. aeruginosa (25%), and A. baumannii (15%) was reduced considerably. The bacterial membrane of all strains was not affected by O3 but presented a significant increase of ROS in E. coli (90 ± 14%), P. aeruginosa (62.5 ± 19%), and A. baumanni (52.6 ± 5%); (4) Conclusion: Low doses of ozone were able to interfere in the cell viability of most strains studied, and although it does not cause damage to the bacterial membrane, increased levels of reactive ROS are responsible for causing a detrimental effect in the lipids, proteins, and DNA metabolism.
ARTICLE | doi:10.20944/preprints202011.0204.v1
Subject: Medicine & Pharmacology, Allergology Keywords: hypoxia; cisplatin sensitivity; mitochondrial fission; ROS; head and neck squamous cell carcinoma
Online: 5 November 2020 (10:02:19 CET)
Chemotherapy treatment based on Cisplatin (CDDP) is established as the drug of choice for head and neck squamous cell carcinoma (HNSCC). Malignant tumors respond to microenvironment alteration through a dynamic balance of mitochondrial fission and fusion. HNSCC is known to have hypoxic conditions, yet the effects and underlying mechanisms of hypoxia on chemosensitivity and mitochondrial dynamics remain unclear. We found that hypoxia promoted mitochondrial fission and CDDP sensitivity in HNSCC cells. Importantly, Mff was shown to be correlated with chemosensitivity in clinical samples of HNSCC that underwent a hypoxic condition. Hypoxia-inducible factor 1 α-subunit (HIF-1α) dramatically increased Mff transcriptional expression and directly bound to Mff. Hypoxia enhanced the release of reactive oxygen species (ROS) and upregulated the expression of Mff via HIF-1α in HNSCC cells. ROS depletion in HNSCC cells attenuated HIF-1α, Mff expression, and mitochondrial fission. Moreover, a knockdown of Mff suppressed hypoxia-induced mitochondrial fission and decreased CDDP chemosensitivity in vivo and in vitro. Our findings revealed that the hypoxia-induced release of ROS promoted mitochondrial fission and CDDP chemosensitivity via the regulation of HIF-1α/Mff in HNSCC cells, indicating that Mff may serve as a new biomarker to predict neoadjuvant chemosensitivity in HNSCC patients
ARTICLE | doi:10.20944/preprints202009.0473.v1
Subject: Life Sciences, Molecular Biology Keywords: antioxidant enzymes; DNA methylation; epigenetics; plant resistance; root-knot nematodes; ROS; tomato
Online: 20 September 2020 (14:35:29 CEST)
Two wild-type field populations of root-knot nematodes (Mi-Vfield, Mj-TunC2field), and two isolates selected for virulence in laboratory on resistant tomato cultivars (SM2V, SM11C2), were used to induce a resistance reaction in tomato to the soil-borne parasites. Epigenetic and metabolic mechanisms of resistance were detected and compared with those occurring in partially or fully successful infections. The activated epigenetic mechanisms in plant resistance, as opposed to those activated in infected plants, were detected by analysing the methylated status of total DNA, by ELISA methods, and the expression level of key genes involved in the methylation pathway, by qRT-PCR. DNA hypo-methylation and down-regulation of two methyl-transferase genes (CMT2, DRM5), characterized the only true resistant reaction obtained by inoculating the Mi-1.2-carrying resistant tomato cv Rossol with the avirulent field population Mi-Vfield. On the contrary, in the roots into which nematodes were allowed to develop and reproduce, total DNA was generally found to be hyper-methylated and methyl-transferase genes up-loaded. DNA hypo-methylation was considered to be the upstream mechanism that triggers the general gene over-expression observed in plant resistance. Gene silencing induced by nematodes may be obtained through DNA hyper-methylation and methyl-transferase gene activation. Plant resistance is also characterized by an inhibition of the anti-oxidant enzyme system and activation of the defence enzyme chitinase, as opposed to the activation of such a system and inhibition of the defence enzyme glucanase in roots infested by nematodes.
ARTICLE | doi:10.20944/preprints202007.0235.v1
Subject: Biology, Physiology Keywords: cadmium; glutathione; glutathione reductase; malondialdehyde; metallothionein; Mytilus galloprovincialis; oxidative stress; ROS scavenging
Online: 11 July 2020 (09:26:12 CEST)
Exposure to metals is known to generate oxidative stress in living organisms, which are able to respond with the induction of antioxidant defenses, both enzymatic and non-enzymatic. The aim of this work is to study the correlation among several non-enzymatic component of the antioxidant system, that are physiologically related to both metal sequestration and defense against metal-induced oxidative stress, using the blue mussels (Mytilus galloprovincialis) as model organism. Specimens of this marine bivalve were experimentally exposed to cadmium (Cd), used as oxidative stress risk inducer. Cd, metallothionein (MT), glutathione (GSH), malondialdehyde (MDA) contents, and glutathione reductase (GR) activity in gills and in digestive glands were assessed at 0, 12, 24, 48, 72 and 96 h. The obtained results provide new data about the relationships among the non-enzymatic antioxidant cellular components considered in this study. These constitute the prompt physiological responses to the risk of oxidative stress in blue mussels exposed to Cd in controlled laboratory conditions.
ARTICLE | doi:10.20944/preprints202005.0019.v1
Subject: Life Sciences, Microbiology Keywords: Barleria lupulina; cytotoxicity activity; MTT; NRU; ROS; MMP; THP-1 cell line
Online: 2 May 2020 (16:07:45 CEST)
Background: Barleria lupulina Lindl. (Hop-headed) is a small shrub, possess potent anti-inflammatory, analgesic, anti-leukemic, antitumor, anti-hyperglycemic, anti-amoebic, virucidal, diuretic, bactericidal and antibiotic properties. Methods: Cytotoxicity, bioactive assay and genetic analysis of B. lupulina were investigated in the present communication. The leaf extract was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), Neutral red uptake (NRU), DNA fragment, reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP) assay, gene expression analysis and cDNA synthesis to evaluate anti-cancerous potency using cancerous THP-1 cell lines in vitro and in vivo. Results: HPTLC analysis reveals four spots and GC-MS analysis displayed the presence of eleven bioactive compounds among which benzofuranon, hexadecanoic acid, ethyl 9,12,15-octadecatrienoate, and 3,7,11,15-tetramethyl-2-hexadecanoic acid were the most prominent compounds. The ethanolic extract showed significant cytotoxicity (P<0.5) against THP-1 cell line at a concentration of 1mg/mL. The cells were also observed for apoptosis through DNA fragmentation in B. lupulina treated cells. Conclusions: It can be concluded that if the dose range was further refined within the range of 100-1000 µg/mL there could be dose at which the entire population of the THP-1 cell line would be apoptosis induced. The extract induced ROS in the cells after 30 minutes of exposure displaying cytotoxic effects and DNA fragmentation assay.
ARTICLE | doi:10.20944/preprints201807.0558.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: robotics; kindergarten; education; robot operating system; ROS; Pepper; , human-robot interaction; HRI
Online: 30 July 2018 (05:31:12 CEST)
In this work we report on our effort to design and implement an early introduction to basic robotics principles for children at kindergarten age. The humanoid robot Pepper, which is a great platform for human-robot interaction experiments, was presenting the lecture by reading out the contents to the children making use of its speech synthesis capability. One of the main challenges of this effort was to explain complex robotics contents in a way that pre-school children could follow the basic principles and ideas using examples from their world of experience. A quiz in a Runaround-game-show style after the lecture activated the children to recap the contents they acquired about how mobile robots work in principle. Besides the thrill being exposed to a mobile robot that would also react to the children, they were very excited and at the same time very concentrated. What sets apart our effort from other work is that part of the lecturing is actually done by a robot itself and that a quiz at the end of the lesson is done using robots as well. To the best of our knowledge this is one of only few attempts to use Pepper not as a tele-teaching tool, but as the teacher itself in order to engage pre-school children with complex robotics contents. We got very positive feedback from the children as well as from their educators.
ARTICLE | doi:10.20944/preprints202108.0006.v1
Subject: Medicine & Pharmacology, Allergology Keywords: cultured neurons; insulin; glutamate; [Ca2+]i; mitochondrial potential; ATP; oxygen consumption rate; superoxide; ROS
Online: 2 August 2021 (09:10:44 CEST)
Glutamate excitotoxicity is implicated in the pathogenesis of many disorders, including stroke, traumatic brain injury, and Alzheimer’s disease, for which central insulin resistance is a comorbid condition. Massive glutamate release primarily through ionotropic N-methyl-D-aspartate receptors (NMDARs) causes a sustained rise in [Ca2+]i, followed by mitochondrial depolarization and an increase in intracellular O2• (superoxide) production. Recently, we found that insulin protected neurons against excitotoxicity by diminishing the delayed calcium deregulation (DCD), However, a role of insulin in superoxide production in excitotoxicity still needs to be clarified. The present study is aimed to investigate the effects of insulin on glutamate-evoked superoxide generation and DCD using the fluorescent indicators dihydroethidium, MitoSOX Red, and Fura-FF in rats cultured cortical neurons. We found that insulin significantly diminished both the intracellular and mitochondrial superoxide production in neurons exposed to glutamate and there was a strong linear correlation between [Ca2+]i and intracellular superoxide. MK 801, an inhibitor of NMDAR-gated Ca2+ influx, completely abrogated the glutamate effects in both the presence and absence of insulin. In experiments on sister cultures, insulin diminishes neuronal death. Thus, collectively, data obtained suggest that insulin diminishes glutamate-induced superoxide production in neurons via fall of [Ca2+]i increased and thereby improves viability of neurons
REVIEW | doi:10.20944/preprints202106.0305.v1
Subject: Medicine & Pharmacology, Allergology Keywords: dietary flavonoids; cardioprotective effects; ROS scavenging; myocardial dysfunction; bioavailability and drug metabolism; toxicity; drug discovery
Online: 11 June 2021 (08:44:01 CEST)
Flavonoids comprise a large group of structurally diverse polyphenolic compounds of plant origin and are abundantly found in human diet such as fruits, vegetables, grains, tea, dairy products, red wine and so on. Major classes of flavonoids include flavonols, flavones, flavanones, flavanols, anthocyanidins, isoflavones, and chalcones. Owing to their potential health benefits and medicinal significance, flavonoids are now considered as an indispensable component in a variety of medicinal, pharmaceutical, nutraceutical, and cosmetic preparations. However, flavonoids play a significant role in preventing cardiovascular diseases (CVDs), which could be mainly due to their antioxidant, antiatherogenic, and antithrombotic effects. Epidemiological and in vitro/in vivo evidences of antioxidant effects support the cardioprotective function of dietary flavonoids. Further, the inhibition of LDL oxidation and platelet aggregation following regular consumption of food containing flavonoids and moderate consumption of red wine might protect against atherosclerosis and thrombosis. A study suggests that daily intake of 100 mg of flavonoids through diet may reduce the risk of developing morbidity and mortality due to coronary heart disease (CHD) by approximately 10%. This review summarizes dietary flavonoids with their sources and potential health implications in CVDs including various redox-active cardioprotective (molecular) mechanisms with antioxidant effects. Pharmacokinetic (oral bioavailability, drug metabolism), toxicological and therapeutic aspects of dietary flavonoids are also addressed herein with future directions for the discovery and development of useful drug candidates/ therapeutic molecules.
REVIEW | doi:10.20944/preprints202105.0334.v1
Subject: Keywords: RES; ROS; reactive chemical species; electrophile signaling; cysteine; LDE; T-REX; G-REX; Chemical Biology
Online: 14 May 2021 (13:45:08 CEST)
In this tutorial review, we compare and contrast the chemical mechanisms of electrophile/oxidant sensing, and the molecular mechanisms of signal propagation. We critically analyze biological systems in which these different pathways are believed to be manifest and what the data really mean. Finally, we discuss applications of this knowledge to disease treatment and drug development.
REVIEW | doi:10.20944/preprints202007.0222.v1
Subject: Chemistry, Medicinal Chemistry Keywords: ROS; oxidative stress; catalytic antioxidants; superoxide dismutase; catalase; peroxidase; manganese; salen-type ligands; animal studies
Online: 11 July 2020 (03:30:41 CEST)
Manganosalen complexes are coordination compounds that possess a chelating salen-type ligand, a class of bis-Schiff bases obtained by condensation of salicylaldehyde and a diamine. They may act as catalytic antioxidants mimicking both the structure and the reactivity of the native antioxidant enzymes active site. Thus, manganosalen complexes have shown to exhibit superoxide dismutase, catalase, and glutathione peroxidase activities, and they could potentially facilitate the scavenging of excess ROS, thereby restoring the redox balance in the damaged cells and organs. Initial catalytic studies compared the potency of these compounds as antioxidants in terms of rate constants of the chemical reactivity against ROS, giving catalytic values approaching and even exceeding that of the native antioxidative enzymes. Although most of these catalytic studies lack of biological relevance, subsequent in vitro studies have confirmed the efficiency of many manganosalen complexes in oxidative stress models. These synthetic catalytic scavengers, cheaper than natural antioxidants, have accordingly attracted intensive attention for the therapy of ROS-mediated injuries. The aim of this review is to focus on in vivo studies performed on manganosalen complexes and their activity on the treatment of several pathological disorders associated with oxidative damage. This disorders, ranging from the prevention of fetal malformations to the extension of lifespan, include neurodegenerative, inflammatory and cardiovascular diseases, tissue injury, and other damages related to liver, kidney or lungs.
ARTICLE | doi:10.20944/preprints201702.0080.v1
Subject: Earth Sciences, Environmental Sciences Keywords: ROS; snow; rain; flood; WRF; numerical weather forecast; energy balance; discharge estimation; early alert system
Online: 22 February 2017 (04:26:49 CET)
From June 18 to 19, 2013, the Ésera river in the Pyrenees, Northern Spain, caused widespread damage due to flooding as a result of torrential rains and sustained snowmelt. We estimate the contribution of snow melt to total discharge applying a snow energy balance to the catchment. Precipitation is derived from sparse local measurements and the WRF-ARW model over three nested domains, down to a grid cell size of 2 km. Temperature profiles, precipitation and precipitation gradient are well simulated, although with a possible displacement regarding the observations. Snowpack melting was correctly reproduced and verified in three instrumented sites, and according to satellite images. We found that the hydrological simulations agree well with measured discharge. Snowmelt represented 33% of total runoff during the main flood event and 23% at peak flow. The snow energy balance model indicates that most of the energy for snow melt during the day of maximum precipitation came from turbulent fluxes. This approach forecast correctly peak flow and discharge during normal conditions at least 24h in advance and could give an early warning of the extreme event 2.5 days before.
ARTICLE | doi:10.20944/preprints202108.0122.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Vaping, disposable e-cigarettes, vape bars, flavoring, flavoring chemicals, Reactive Oxidative Species (ROS), disposables, oxidative stress
Online: 4 August 2021 (21:48:02 CEST)
Studies have shown that aerosols generated from flavored e-cigarettes contain Reactive Oxygen Species (ROS), promoting oxidative stress-induced damage within pulmonary cells. Our lab investigated the ROS content of e-cigarette vapor generated from disposable vape bars, a product exempt from the Federal Drug Enforcement Agency’s (FDA) 2020 flavor ban. Specifically, we analyzed vape bars belonging to multiple flavor categories (Tobacco, Minty Fruit, Fruity, Minty/Menthol, Desserts, and Drinks), manufactured by various vendors and of various nicotine concentrations (0-6.8%). Aerosols from these flavored vape bars were generated by a single puff aerosol generator and individually bubbled through a fluorogenic solution to detect and semi-quantify ROS in H2O2 equivalents generated by the vape bars. We compared and contrasted the ROS levels generated by each flavor as an indirect determinant of oxidative stress potential by these disposable vape bars. Our results showed that ROS concentration (μM) of aerosols produced from the vape bars varied significantly between different flavors and a function of nicotine concentration. Likewise, our results suggest that flavoring chemicals and nicotine concentration play a role in alerting ROS production in e-cigarette aerosols. Our study provides insight into the differential health effects of flavored disposable vape bars and the need for their regulation.
ARTICLE | doi:10.20944/preprints202008.0077.v1
Subject: Chemistry, Medicinal Chemistry Keywords: anti-oxidant activity; anti-oxidant enzymes, anti-proliferative activity; maslinic acid; melanoma; Olea europaea; ROS levels
Online: 4 August 2020 (04:57:13 CEST)
Maslinic acid (MA) is a natural triterpene from Olea europaea whose pharmacological functions have been showed. The objective of this study was to examine MA effect on cell viability (by MTT assay), reactive oxygen species (ROS levels, by flow cytometry) and key anti-oxidant enzyme activities (by spectrophotometry) in murine skin melanoma (B16F10) cells compared to healthy cells (A10). MA induced cytotoxic effects in cancer cells (IC50 42 µM) whereas no effect was found in A10 cells treated with MA (up to 210 µM). In order to produce a stress situation in cells, 0.15 mM of H2O2 were added. Under stressful conditions, MA protected both cell lines against oxidative damage, decreasing intracellular ROS, being higher in B16F10 than in A10 cells. The treatment with H2O2 and without MA produced different responses in anti-oxidant enzymes activities depending on cell line. In A10 cells, all enzymes were up-regulated, but in B16F10 cells only superoxide dismutase, glutathione S-transferase and glutathione peroxidase increased their activities. MA restored the enzyme activities to similar levels than control group in both cell lines, highlighting that in A10 cells the highest MA doses induced values lower than control. Overall, these findings demonstrate the great anti-oxidant capacity of MA.
REVIEW | doi:10.20944/preprints202002.0342.v1
Subject: Life Sciences, Biochemistry Keywords: cathepsin; chronic obstructive pulmonary disease (COPD); cigarette smoke; cysteine; cysteine protease; emphysema; oxidation; proteolysis; ROS; thiol
Online: 24 February 2020 (02:48:00 CET)
Besides their primary involvement in the recycling and degradation of proteins in endo-lysosomal compartments but also in specialized biological functions, cysteine cathepsins are pivotal proteolytic contributors of various deleterious diseases. While the molecular mechanisms of regulation by their natural inhibitors have been exhaustively studied, less is currently known about how their enzymatic activity is modulated during the redox imbalance associated with an oxidative stress and their exposure resistance to oxidants. More specifically, there is only patchy information on the regulation of lung cysteine cathepsins, while the respiratory system is directly exposed to countless exogenous oxidants contained in dust, tobacco, combustion fumes, and industrial or domestic particles. Papain-like enzymes (clan CA, family C1, subfamily C1A) encompass a conserved catalytic thiolate-imidazolium pair (Cys25-His159) in their active site. Despite the sulfhydryl group (with a low acidic pKa) is a potent nucleophile highly susceptible to chemical modifications, some cysteine cathepsins reveal an unanticipated resistance to oxidative stress. Beside an introductory chapter and a peculiar attention to lung cysteine cathepsins, the purpose of this review is to afford a concise update of the current knowledge on molecular mechanisms associated to the regulation of cysteine cathepsins by redox balance and by oxidants (e.g. Michael acceptors, reactive oxygen and nitrogen species).
Subject: Physical Sciences, Radiation & Radiography Keywords: radiation track chemistry; chemical track structure; oxygen effect; oxygen depletion; ion beam therapy; ROS; superoxide anion
Online: 5 December 2019 (03:32:18 CET)
The radiosensitivity of biological systems is strongly affected by the system oxygenation. On the nanoscopic scale and molecular level, this effect is considered to be strongly related to the indirect damage of radiation. Even though particle track radiolysis has been the object of several studies, still little is known about the nanoscopic impact of target oxygenation on the radical yields. We present here an extension of the chemical module of the Monte Carlo particle track structure code TRAX, taking into account the presence of dissolved molecular oxygen in the target material. The impact of the target oxygenation level on the chemical track evolution and the yields of all the relevant chemical species is studied in water under different irradiation conditions: different linear energy transfer (LET) values, different oxygenation levels, and different particle types. Especially for low LET radiation, a large production of two highly toxic species (HO2• and O2•− ), which are not produced in anoxic conditions, is predicted and quantified in oxygenated solutions. The remarkable correlation between the HO2• and O2•− production yield and the oxygen enhancement ratio observed in biological systems suggests a direct or indirect involvement of HO2• and O2•− in the oxygen sensitization effect. The results are in agreement with available experimental data and previous computational approaches. An analysis of the oxygen depletion rate in different radiation conditions is also reported.
ARTICLE | doi:10.20944/preprints202009.0536.v1
Subject: Chemistry, Physical Chemistry Keywords: 3,3’,5,5’-tetramethylbenzidine; reactive oxygen species (ROS); reactive nitrogen species (RNS); photoacoustic probes; optical sensors; singlet oxygen
Online: 23 September 2020 (04:17:34 CEST)
Photoacoustic imaging is attracting a great deal of interest owing to its distinct advantages over other imaging techniques such as fluorescence or magnetic resonance image. Availability of photoacoustic probes for reactive oxygen and nitrogen species (ROS/RNS) could shed light on a plethora of biological processes mediated by these key intermediates. Tetramethylbenzidine (TMB) is a non-toxic and non-mutagenic colorless dye that develops a distinctive blue color upon oxidation. In this work we have investigated the potential of TMB as photoacoustic probe for ROS/RNS. Our results indicate that TMB reacts with hypochlorite, hydrogen peroxide, singlet oxygen and nitrogen dioxide to produce the blue oxidation product, while ROS such as the superoxide radical anion, sodium peroxide, hydroxyl radical or peroxynitrite yield a colorless oxidation product. TMB does not penetrate Escherichia coli cytoplasm but is capable of detecting singlet oxygen generated in its outer membrane.
ARTICLE | doi:10.20944/preprints202008.0112.v1
Subject: Chemistry, Medicinal Chemistry Keywords: AKT/PI3K signaling pathway; apoptosis; human hepatocarcinoma HepG2 cells; migration activity; proliferation; oxidative stress; ROS level; uvaol
Online: 5 August 2020 (05:58:26 CEST)
Natural products have a significant role in the development of new drugs, being relevant the pentacyclic triterpenes extracted from Olea europaea. Anticancer effect of uvaol, a natural triterpene, has been scarcely studied. The aim of this study was to understand the anticancer mechanism of uvaol in HepG2 cell line. Cytotoxicity results showed a selectivity effect of uvaol with higher influence in HepG2 than WRL68 cells used as control. Uvaol presented anti-migratory capacity in HepG2, supported by the morphological changes and higher HSP-60 expression. This compound also induced arrest in G0/G1 phase and an increase in apoptosis rate. These results are supported by decreased Bcl-2 expression and down-regulation of AKT/PI3K signaling pathway. A reduction in reactive oxygen species levels in HepG2 cells was observed. Altogether, results showed anti-proliferative and pro-apoptotic effect of uvaol on hepatocellular carcinoma, constituting an interesting challenge in the development of new treatments against this type of cancer.
ARTICLE | doi:10.20944/preprints202205.0246.v1
Subject: Biology, Horticulture Keywords: oriental melon; squash; graft; exogenous naphthylacetic acid; transcriptomic analysis; endogenous hormone; signal transduction; ROS scavenging; vascular bundle formation
Online: 19 May 2022 (03:22:20 CEST)
The plant graft healing process is an intricate development influenced by numerous endogenous and environmental factors. This process involves the histological changes, physiological and biochemical reactions, signal transduction, and hormone exchanges in the grafting junction. Studies have shown that applying exogenous plant growth regulators can effectively promote the graft healing process and improve the quality of grafted plantlets. However, the physiological and molecular mechanism of graft healing formation remains unclear. In our present study, transcriptome changes in the melon and cucurbita genomes were analyzed between control and NAA treatment, and we provided the first view of complex networks to regulate graft healing under exogenous NAA application. The results showed that the exogenous NAA application could accelerate the graft healing process of oriental melon scion grafted onto squash rootstock through histological observation, increase the SOD, POD, PAL, and PPO activities during graft union development and enhance the contents of IAA, GA3, and ZR except for the IL stage. The DEGs were identified in the plant hormone signal-transduction, phenylpropanoid biosynthesis, and phenylalanine metabolism through transcriptome analysis of CK vs. NAA at the IL, CA, and VB stage by KEGG pathway enrichment analysis. Moreover, the exogenous NAA application significantly promoted the expression of genes involved in the hormone signal-transduction pathway, ROS scavenging system, and vascular bundle formation.
REVIEW | doi:10.20944/preprints202010.0051.v1
Subject: Biology, Anatomy & Morphology Keywords: melatonin; ROS; NO; posttranslational modifications (PMTs); abiotic stress; drought; salinity; high temperature; high light; waterlogging; abiotic stress combination
Online: 5 October 2020 (07:48:29 CEST)
Abiotic stress in plants is an increasingly common problem in agriculture, and thus, studies on plant treatments with specific certain compounds that may help to mitigate these effects have increased in recent years Melatonin (MET) application and its role in mitigating the negative effects of abiotic stress in plants have become important in the last few years. MET, a derivative of tryptophan, is an important plant-related response molecule involved in the growth, development, and reproduction of plants, and the induction of different stress factors. In addition, MET plays a protective role against different abiotic stresses such as salinity, high/low temperature, high light, waterlogging, nutrient deficiency and stress combination by regulating both the enzymatic and non-enzymatic antioxidant defense systems. Also, MET interacts with many signaling molecules, among these, reactive oxygen species (ROS) and nitric oxide (NO), and participates in a wide variety of physiological reactions. It is well known that NO produces S-nitrosylation and NO2-Tyr of important antioxidant-related proteins, being this an important mechanism for maintaining the antioxidant capacity of the AsA/GSH cycle under nitro-oxidative conditions, being extensively reviewed here under different abiotic stress conditions. Lastly, in this review, we show the coordination between NO and MET as a long-range signaling molecule, regulating many responses in plants, including plant growth and abiotic stress tolerance. Despite all the knowledge acquired over the years, there is still more to know about how MET and NO act on tolerance to abiotic stresses.
ARTICLE | doi:10.20944/preprints202202.0132.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Tobacco Free Nicotine (TFN); Synthetic Nicotine; Tobacco-derived Nicotine; vape-bar; Electronic Nicotine Delivery Systems; Reactive Oxygen Species (ROS)
Online: 9 February 2022 (10:37:28 CET)
Tobacco Free Nicotine (TFN) Electronic Nicotine Delivery Systems (ENDS) are yet to be classified as tobacco products; consequently, there is ambiguity over whether Food and Drug Administration (FDA) regulatory authority can be extended to include TFN e-cigarettes. In recent years, a more significant number of e-cigarette companies have been manufacturing TFN-containing e-cigarettes and e-liquids to circumvent FDA regulations. While studies have shown that aerosols generated from tobacco-derived nicotine-containing e-cigarettes contain significant Reactive Oxygen Species (ROS) levels, no comparison studies have been conducted using TFN e-cigarettes. This study uses a single puff aerosol generator to aerosolize TFN and tobacco-derived nicotine-containing vape-products and subsequently involves semi-quantifying ROS generated by these vape products in H2O2 equivalents. We found that the differences between ROS levels generated from TFN and tobacco-derived nicotine-containing vape products vary by flavor. TFN tobacco flavors and fruit flavors are more toxic in terms of ROS generation than menthol/ice and drink/beverage flavored products using TFN. The type of salt nicotine used in vape products, TFN or tobacco-derived nicotine, impacts the level of ROS generated from flavored vape products. Thus, a better understanding of the type of salt nicotine used in e-cigarettes (tobacco-derived or synthetic), has modulating effect on lung oxidative stress.
ARTICLE | doi:10.20944/preprints202010.0189.v1
Subject: Chemistry, Analytical Chemistry Keywords: antioxidants for the treatment of ROS; new ester of eugenol; cosmetic formulations with clove water; skin penetration; Franz cell
Online: 9 October 2020 (08:59:05 CEST)
The main focus of this work is to extend the knowledge about the complexity of issues of oxidative stress. Natural compounds play a serious role in multiple aspects of both human, leading to clear health-promoting effects. This work is focused on the potential application cosmetic formulations containing including but not limited to of clove water and isolated clove oils on their aid in the control of the diseases. The aim of our work was to prepare to evaluate cosmetic formulations containing clove oil, eugenol or new eugenol ester derivative (eugenyl dichloroacetate - EDChA) but also cosmetic formulations containing the aqueous phase obtained after separation of essential oil following the clove buds steam distillation. To evaluate the antioxidants transdermal delivery system, in vitro permeation experiments in a Franz diffusion cell were performed using pig skin. The antioxidative capacity of the cosmetic formulations obtained was determined by the DPPH free radical reduction method. In the next stage, the antioxidant activity (DPPH, ABTS, and Folin–Ciocalteu methods) of the fluid that penetrated through pig skin and of the fluid obtained after skin extraction, were also evaluated. For comparison, studies of cosmetic formulation containing alone dichloroacetic acid (DChAA) were as well carried out. The obtained cosmetic formulations were characterized by of antioxidant activity estimated after 24 hours of conducting the experiment, which indicates long-term protection against reactive oxygen species (ROS) in the deeper layers of the skin. The results of this work contribute to the development of cosmetic formulations with antioxidant potential, emphasizing that the water phases are waste from the process of cloves steam distillation and are not used to prepare cosmetic formulations. The use of waste water from the clove buds steam distillation process is environmentally friendly and not allows us to waste, containing however valuable biologically active compounds (furfural, methyl salicylate, 4-allilofenol, eugenol, α- and β-caryophyllene, eugenyl acetate, β-caryophyllene oxide). Together, these results suggest that cosmetic formulations may be potential drug candidates for chemopreventive, antineoplastic and antimutagenic therapy.
ARTICLE | doi:10.20944/preprints202009.0171.v1
Subject: Biology, Physiology Keywords: protein-protein interaction network; GPx; glutathione peroxidases genes; ciliate protists; copper; metals; antioxidant system; free-radicals; ROS; reactive oxygen species
Online: 8 September 2020 (04:59:18 CEST)
Glutathione peroxidases (GPxs) form a broad family of antioxidant proteins essential for maintaining redox homeostasis in eukaryotic cells. In this study, we used an integrative approach that combines bioinformatics, molecular biology, and biochemistry to investigate the role of GPxs in reactive oxygen species detoxification in the unicellular eukaryotic model organism Tetrahymena thermophila. Both phylogenetic and mechanistic empirical model analyses provided indications about the evolutionary relationships among the GPXs of Tetrahymena and the orthologous enzymes of phylogenetically related species. In-silico gene characterization and text mining were used to predict the functional relationships between GPxs and other physiologically-relevant processes. The GPx genes contain conserved transcriptional regulatory elements in the promoter region, which suggest that transcription is under tight control of specialized signaling pathways. The bioinformatic findings were next experimentally validated by studying the time course of copper (Cu)-dependent regulation of gene transcription and enzymatic activity. Results emphasize the role of GPxs in the detoxification pathways that, by complex regulation of Cu-dependent GPx gene expression, enables Tetrahymena to survive in high Cu concentrations and the associated redox environment.
ARTICLE | doi:10.20944/preprints202003.0148.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: osteosarcoma; cancer; tumor; vitamin D; vitamin D deficiency; vitamin D receptor; vdr; mitochondria; ROS; SOD; SOD1; SOD2; superoxide; superoxide dismutase
Online: 9 March 2020 (02:40:08 CET)
Superoxide, a form of reactive oxygen species (ROS), is catabolized by superoxide dismutase (SOD) and contributes to carcinogenesis via the oxidative damage it inflicts on cells. The aim of this research was to analyze the potential vitamin D-mediated regulation of the antioxidative “SOD1-to-SOD2 switch” within the human MG-63 osteosarcoma model. For this study; real-time PCR analysis was performed using MG-63 cells exposed to metabolically active 1,25(OH)2D3. Frist; a sustained statistically significant >2-fold suppression of proliferating cell nuclear antigen (PCNA) transcripts was observed after 10nM but not at 100nM of 1,25(OH)2D3 treatment; suggesting a cytostatic effect. In order to assess regulators of mitochondrial oxidative phosphorylation; gene expression of COX2 and COX4l1 of the mitochondrial complex IV and antioxidative enzymes (SOD1; SOD2 and Catalase (CAT)) were monitored. For COX2 and COX4l1; no changes in gene expression were observed. However; a concomitant decrease in CAT and SOD1 mRNA; and increase in SOD2 mRNA after 24 hours of 10nM 1,25(OH)2D3 treatment were observed. A ~8-fold increase in SOD2 mRNA was apparent after 48 hours. The significant increase in SOD2 activity in the presence of vitamin D indicates an antioxidant potential and sensitization of vitamin D during osteosarcoma transformation and mitochondrial detoxification over time.
ARTICLE | doi:10.20944/preprints201608.0114.v1
Subject: Life Sciences, Biophysics Keywords: 8-OHdG (8-hydroxy- 2-deoxyguanosine), vitamin A, vitamin C, vitamin E, ROS (reactive oxygen species), TAS (total antioxidant status)
Online: 10 August 2016 (16:49:20 CEST)
The present study was aimed to evaluate the levels of oxidative stress markers in breast diseases by measuring the 8-hydoxy-2-deoxyguanosine (8-OHdG), vitamin A, vitamin C, vitamin E and total antioxidant status (TAS) alterations in relation to cell proliferation activity and disease progression. Significant increases in the level of oxidative damage marker 8-OHdG and cell proliferation activity were observed in breast carcinoma patients in comparison to benign and normal controls, which were accompanied by significant decrease in non enzymatic antioxidants and TAS concentrations. 8-OHdG and cell proliferation level were negatively correlated with non enzymatic antioxidants viz., Vitamin A, Vitamin C, vitamin E level and total antioxidant activity. Altered levels of biomarkers of oxidative stress and cell proliferation activity amongst the malignant, benign and controls suggest a correlation of increased oxidative stress and cell proliferation activity in the progression of disease in breast carcinoma patients. Among the oxidative stress markers and cell proliferation index, decreased level of vitamin A, vitamin C, vitamin E, TAS and increased level of 8-OHdG, cell proliferation index emerged as best predicted biomarkers for subjects with malignancy and benign breast disease.
REVIEW | doi:10.20944/preprints202111.0346.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: Ascending aorta aneurysm (AsAA); reactive oxygen species (ROS); oxidative stress; onset and progression of sporadic AsAA; management of AsAA; biomarkers and targets
Online: 19 November 2021 (11:19:37 CET)
Ascending aorta aneurysm (AsAA) is a complex disease, currently defined an inflammatory disease. In the sporadic form, AsAA has, indeed, a complex physiopathology with a strong inflammatory basis, significantly modulated by genetic variants in innate/inflammatory genes, acting as independent risk factors and as largely evidenced in our recent studies performed during the last 10 years. Based on these premises, here, we want to revise the impact of reactive oxygen species (ROS) and oxidative stress on AsAA pathophysiology and consequently on the onset and progression of sporadic AsAA. This might consent to add other important pieces in the intricate puzzle of the pathophysiology of this disease with the translational aim to identify biomarkers and targets to apply in the complex management of AsAA, by facilitating the AsAA diagnosis currently based only on imaging evaluations, and the treatment exclusively founded on surgery approaches.
ARTICLE | doi:10.20944/preprints201808.0362.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Communication Fail-Over, Fault Diagnosis, Limpet, On-board Processing, ORCA Hub, Real-time Condition Monitoring, Remote Sensing, Robots, Robot Sensing Systems, ROS Interface.
Online: 20 August 2018 (19:24:46 CEST)
The oil and gas industry faces increasing pressure to remove people from dangerous offshore environments. Robots present a cost-effective and safe method for inspection, repair and maintenance of topside and marine offshore infrastructure. In this work, we introduce a new immobile multi-sensing robot, the Limpet, which is designed to be low-cost and highly manufacturable, and thus can be deployed in huge collectives for monitoring offshore platforms. The Limpet can be considered an instrument, where in abstract terms, an instrument is a device that transforms a physical variable of interest (measurand) into a form that is suitable for recording (measurement). The Limpet is designed to be part of the ORCA (Offshore Robotics for Certification of Assets) Hub System, which consists of the offshore assets and all the robots (UAVs, drones, mobile legged robots etc.) interacting with them. The Limpet comprises the sensing aspect of the ORCA Hub System. We integrated the Limpet with Robot Operating System (ROS), which allows it to interact with other robots in the ORCA Hub System. In this work, we demonstrate how the Limpet can be used to achieve real-time condition monitoring for offshore structures, by combining remote sensing with signal processing techniques. We show an example of this approach for monitoring offshore wind turbines. We demonstrate the use of four different communication systems (WiFi, serial, LoRa and optical communication) for the condition monitoring process. By processing the sensor data on-board, we reduce the information density of our transmissions, which allows us to substitute short-range high-bandwidth communication systems with low-bandwidth long-range communication systems. We train our classifier offline and transfer its parameters to the Limpet for online classification, where it makes an autonomous decision based on the condition of the monitored structure.
REVIEW | doi:10.20944/preprints202207.0171.v1
Subject: Medicine & Pharmacology, Behavioral Neuroscience Keywords: Alzheimer’s; aging; amygdala; brain plasticity; CA1; CA3; chronic stress; cognition; GABA; HIF-1; hippocampus; hypoxia; neurogenesis; Parkinson’s; prefrontal cortex; PSA-NCAM; ROS; spatial learning
Online: 12 July 2022 (04:25:55 CEST)
Stress plays a central role in functioning for all life forms. As humans, we experience stress in a multitude of ways through various types of stimuli. Due to the constancy of stressors in our lives, the nervous system has learned to allosterically adapt to the stimuli, but when the body cannot adapt, chronic stress can have morphological and degenerative impacts on neuroanatomy and cognitive function that may or may not be reversible. This literature review aimed to identify the specific neuroanatomical structures impacted most by the long-term effects of chronic stress and the subsequent relationship the morphological changes had on cognitive function in rodent models. We examined articles published from PubMed, Google Scholar, and Science Direct, while focusing the search on anatomical and neurodegenerative effects associated with chronic stress stimuli. The degenerative effects of various types simulated physiological chronic stress showed the most impact on neurogenesis and neuronal development, brain plasticity, and spatial learning and memory with association to the hippocampus. The hippocampus, amygdala, prefrontal cortex, and hypothalamic-pituitary-adrenal axis (HPA) all had reversible and non-reversible morphological alterations, which also had a direct impact on the brain’s cognitive abilities. While studies regarding chronic stress are still being conducted, future research may be able to further highlight why stressful stimuli can particularly impact these structures and the tangential impacts that it may have on related or adjacent structures.
REVIEW | doi:10.20944/preprints202106.0337.v1
Subject: Life Sciences, Biochemistry Keywords: alcohol use disorders (AUD); cancer, ethanol oxidative and nonoxidative metabolism, acetaldehyde, reactive oxygen species (ROS), DNA adducts, protein damage, cancer stem cells (CSC), epigenetic changes.
Online: 14 June 2021 (09:03:43 CEST)
The World Health Organization identifies alcohol as a cause in several neoplasias of the oro-pharynx cavity, esophagus, gastrointestinal tract, larynx, liver, or female breast. This study re-views ethanol's nonoxidative and oxidative metabolism and one-carbon metabolism that en-compasses both redox and transfer reactions that influence crucial cell proliferation machinery. Ethanol favors the uncontrolled production and action of free radicals that interfere with the maintenance of essential cellular functions. We focus on the generation of protein, DNA, and lipid adducts that interfere with the cellular processes related to growth and differentiation. Ethanol's effects on stem cells responsible for building and repairing tissues are reviewed. Cancer stem cells suffer disturbances related to the expression of cell surface markers, enzymes, and transcription factors after ethanol exposure with consequent dysregulation of mechanisms related to cancer metastasis or resistance to treatments. Our analysis aims to underlie and discuss potential targets that show more sensitivity to ethanol's action and identify specific metabolic routes and metabolic realms that may be corrected to recover metabolic homeostasis after pharmacological interven-tion. Specifically, research should pay attention to reestablish metabolic fluxes by fine-tuning the functioning of specific pathways related to one-carbon metabolism and antioxidant processes.
ARTICLE | doi:10.20944/preprints202105.0132.v1
Subject: Life Sciences, Biochemistry Keywords: aqueous fullerene dispersions; pristine fullerenes; metallofullerenes; ROS homeostasis; oxidative stress; NOX4; Nrf2; PRAR-γ; heme oxygenase 1; NAD(P)H quinone dehydrogenase 1; an-ti-inflammatory pathways
Online: 7 May 2021 (09:38:38 CEST)
Background: Fullerenes and metallofullerenes can be considered promising nanopharmaceuticals themselves and as a basis for chemical modification. As reactive oxygen species homeostasis plays a vital role in cells, the study of their effect on genes involved in oxidative stress and anti-inflammatory response is of particular importance. Methods: Human fetal lung fibroblasts were incubated with aqueous dispersions of C60, C70, and Gd@C82 in concentrations of 5 nM and 1.5 µM for 1, 3, 24, and 72 hours. Cell viability, intracellular ROS, NOX4, NFκB, PRAR-γ, NRF2, heme oxygenase 1, and NAD(P)H quinone dehydrogenase 1 expression have been studied. Results & conclusion: The aqueous dispersions of C60, C70, and Gd@C82 fullerenes are active participants in ROS homeostasis. Low and high concentrations of AFDs have similar effects. C70 was the most inert substance, C60 was the most active substance. All AFDs have both a “prooxidant” and “antioxidant” effect, but with a different balance. Gd@C82 was a substance with more pronounced antioxidant and anti-inflammatory properties, while C70 had more pronounced “prooxidant” properties.
ARTICLE | doi:10.20944/preprints201807.0317.v3
Subject: Life Sciences, Molecular Biology Keywords: Boswellia serrata Roxb.; Curcuma longa L.; intestinal bowel diseases (IBD); Caco-2; PBMC; HMC-1.1; mast cells; cytokines; trans epithelial electrical resistance (TEER); reactive oxygen species (ROS)
Online: 8 November 2018 (04:53:46 CET)
Inflammatory bowel diseases, which consist of chronic inflammatory conditions of the colon and the small intestine, are considered a global disease of our modern society. Recently, the interest toward the use of herbal therapies for the management of inflammatory bowel diseases has increased because of their effectiveness and favorable safety profile, compared to conventional drugs. Boswellia serrata Roxb. and Curcuma longa L. are amongst the most promising herbal drugs, however, their clinical use in inflammatory bowel diseases is limited and little is known on their mechanism of action. The aim of this work was to investigate the effects of two phytochemically characterized extracts of B. serrata and C. longa in an in vitro model of intestinal inflammation. Their impact on cytokine release and reactive oxygen species production, as well as the maintenance of the intestinal barrier function and on intestinal mucosa immune cells infiltration, has been evaluated. The extracts showed a good protective effect on the intestinal epithelium at 1 µg/ml, with TEER values increasing by approximately 1.5 fold, compared to LPS-stimulated cells. C. longa showed an anti-inflammatory mechanism of action, reducing IL-8, TNF-α and IL-6 production by approximately 30%, 25% and 40%, respectively, compared to the inflammatory stimuli. B. serrata action was linked to its antioxidant effect, with ROS production being reduced by 25%, compared to H2O2-stimulated Caco-2 cells. C. longa and B. serrata resulted to be promising agents for the management of inflammatory bowel diseases by modulating in vitro parameters which have been identified in the clinical conditions.
REVIEW | doi:10.20944/preprints201807.0432.v1
Subject: Biology, Plant Sciences Keywords: Seed coat; pericarps; floral bracts; glumes; dead organs enclosing embryos; seed germination; seedling establishment; hydrolytic enzymes; ROS detoxifying enzymes; cell wall modification enzymes; nutrients; phytohormones; nucleases; chitinases; Brassicaceae; Poaceae
Online: 26 July 2018 (09:53:41 CEST)
Plants have evolved a variety of dispersal units whereby the embryo is enclosed by various dead protective layers derived from maternal organs of the reproductive system including seed coats (integuments), pericarps (ovary wall, e.g., indehiscent dry fruits) as well as floral bracts (e.g. glumes) in grasses. Commonly, dead organs enclosing embryos (DOEEs) are assumed to provide a physical shield for embryo protection and means for dispersal in the ecosystem. In this review article, we will highlight recent studies showing that DOEEs of various species across families also have the capability for long-term storage of various substances including active proteins (hydrolases, ROS detoxifying enzymes), nutrients and metabolites that have the potential to support the embryo during storage in the soil and assist in germination and seedling establishment. We discuss a possible role for DOEEs as natural coatings capable of ‘engineering’ the seed microenvironment for the benefit of the embryo, the seedling and the growing plant.
HYPOTHESIS | doi:10.20944/preprints202109.0372.v1
Subject: Life Sciences, Other Keywords: Endometriosis; microchimerism; maternal microchimerism; reproduction; gynaecology; etiology; auto-immune; immune response; hormonal; vascular; genetic; hereditary; male; fetal; fetus; stem cells; pregnancy; Műllerianosis; embryology; ROS; apoptosis; disease; endometrium; basalis; menstruation; post-menopausal; neurogenesis
Online: 22 September 2021 (10:27:52 CEST)
Endometriosis is an oestrogen-dependant reproductive disease, with genetic, vascular, neural, inflammatory and auto-immune characteristics. There are many theories about the etiology of endometriosis, however, all of these theories have limitations and do not explain all the locations that endometriosis is found or types of patients with endometriosis. The objective of this paper is to postulate the hypothesis that endometriosis is caused by Maternal Microchimerism, the presence of maternal cells in the fetus. A literature review was conducted, analysing the characteristics, current etiological theories of endometriosis, theory limitations and relationship of maternal microchimerism and endometriosis. At time of writing, there was no literature on maternal microchimerism and endometriosis. These results suggest that Maternal Microchimerism could be a cause of endometriosis. This could account for the genetic and auto-immune characteristics seen in people with endometriosis, inducing a micro-environment for vascular, neural and epigenetic changes. This could also account for account for endometriosis seen in non-menstruating patients, such as men, fetuses and post-menopausal women and endometriosis found in non-peritoneal locations. If the hypothesis of Maternal Microchimerism is correct, endometriosis could be considered a pregnancy-related disease that could affect all humans, changing the accepted demographics of patients and potentially new diagnostic techniques and treatment options for patients with endometriosis. Further studies are needed to test this hypothesis.