scholarly journals The Antioxidant Effects of a Polyphenol-Rich Grape Pomace ExtractIn VitroDo Not CorrespondIn VivoUsing Exercise as an Oxidant Stimulus

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Aristidis S. Veskoukis ◽  
Antonios Kyparos ◽  
Michalis G. Nikolaidis ◽  
Dimitrios Stagos ◽  
Nektarios Aligiannis ◽  
...  

Fruits, such as grapes, are essential food of the Mediterranean diet. Grape extracts have potent antioxidant and chemopreventive propertiesin vitro. Numerous studies have examined the effects of plant extract administration on redox status at rest in animals and humans but their results are controversial. However, there are no studies comparing thein vitroandin vivoeffects of plant extracts on oxidative stress using exercise as an oxidant stimulus. Thus, the aim of this study was to investigate whether a polyphenol-rich grape pomace extract of theVitis viniferaspecies possessesin vitroantioxidant properties and to examine whether these properties apply in anin vivomodel at rest and during exercise. Our findings indicate that the tested extract exhibits potentin vitroantioxidant properties because it scavenges the DPPH•and ABTS•+radicals and inhibits DNA damage induced by peroxyl and hydroxyl radicals. Administration of the extract in rats generally induced oxidative stress at rest and after exercise whereas exercise performance was not affected. Our findings suggest that the grape pomace extract does not behave with the same wayin vitroandin vivo.

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 112
Author(s):  
Sera Kim ◽  
Mingyeong Kim ◽  
Min-Cheol Kang ◽  
Hyun Hee L. Lee ◽  
Chi Heung Cho ◽  
...  

Oxidative stress, caused by the excessive production of reactive oxygen species (ROS), results in cellular damage. Therefore, functional materials with antioxidant properties are necessary to maintain redox balance. Turmeric leaves (Curcuma longa L. leaves; TL) are known to have antioxidant properties, including 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2′-Azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), and Hydrogen peroxide (H2O2) radical scavenging activity in several studies. The antioxidant effects of TL come from distinct bioactive compounds, such as curcumin, total phenolic compounds, and flavonoids. Therefore, in this study, the antioxidant effects of a water extract of TL (TLE) against H2O2 treatment were assessed in vitro Vero cells and in vivo zebrafish models. The intracellular ROS generation and the proportion of sub-G1 phase cells were evaluated in H2O2- or/and TLE-treated Vero cells to measure the antioxidant activity of TLE. TLE showed outstanding intracellular ROS scavenging activity and significantly decreased the proportion of cells in the sub-G1 phase in a dose-dependent manner. Furthermore, cell death, ROS generation, and lipid peroxidation in the H2O2-treated zebrafish model were attenuated as a consequence of TLE treatment. Collectively, the results from this study suggested that TLE may be an alternative material to relieve ROS generation through its antioxidant properties or a suitable material for the application in a functional food industry.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Andra-Diana Andreicut ◽  
Alina Elena Pârvu ◽  
Augustin Cătălin Mot ◽  
Marcel Pârvu ◽  
Eva Fischer Fodor ◽  
...  

Oxidative stress and inflammation are interlinked processes. The aim of the study was to perform a phytochemical analysis and to evaluate the antioxidant and anti-inflammatory activities of ethanolic Mahonia aquifolium flower (MF), green fruit (MGF), and ripe fruit (MRF) extracts. Plant extract chemical composition was evaluated by HLPC. A DPPH test was used for the in vitro antioxidant activity. The in vivo antioxidant effects and the anti-inflammatory potential were tested on a rat turpentine oil-induced inflammation, by measuring serum nitric oxide (NOx) and TNF-alpha, total oxidative status (TOS), total antioxidant reactivity (TAR), oxidative stress index (OSI), 3-nitrothyrosine (3NT), malondialdehyde (MDA), and total thiols (SH). Extracts were administrated orally in three dilutions (100%, 50%, and 25%) for seven days prior to inflammation. The effects were compared to diclofenac. The HPLC polyphenol and alkaloid analysis revealed chlorogenic acid as the most abundant compound. All extracts had a good in vitro antioxidant activity, decreased NOx, TOS, and 3NT, and increased SH. TNF-alpha was reduced, and TAR increased only by MF and MGF. MDA was not influenced. Our findings suggest that M. aquifolium has anti-inflammatory and antioxidant effects that support the use in primary prevention of the inflammatory processes.


2011 ◽  
Vol 4 (1) ◽  
pp. 20-26 ◽  
Author(s):  
Ružena Sotníková ◽  
Jana Nedelčevová ◽  
Jana Navarová ◽  
Viera Nosáľová ◽  
Katarína Drábiková ◽  
...  

Protection of the vascular endothelium in experimental situationsOne of the factors proposed as mediators of vascular dysfunction observed in diabetes is the increased generation of reactive oxygen species (ROS). This provides support for the use of antioxidants as early and appropriate pharmacological intervention in the development of late diabetic complications. In streptozotocin (STZ)-induced diabetes in rats we observed endothelial dysfuction manifested by reduced endothelium-dependent response to acetylcholine of the superior mesenteric artery (SMA) and aorta, as well as by increased endothelaemia. Changes in endothelium-dependent relaxation of SMA were induced by injury of the nitric oxide radical (·NO)-signalling pathway since the endothelium-derived hyperpolarising factor (EDHF)-component of relaxation was not impaired by diabetes. The endothelial dysfunction was accompanied by decreased ·NO bioavailabity as a consequence of reduced activity of eNOS rather than its reduced expression. The results obtained using the chemiluminiscence method (CL) argue for increased oxidative stress and increased ROS production. The enzyme NAD(P)H-oxidase problably participates in ROS production in the later phases of diabetes. Oxidative stress was also connected with decreased levels of reduced glutathione (GSH) in the early phase of diabetes. After 10 weeks of diabetes, adaptational mechanisms probably took place because GSH levels were not changed compared to controls. Antioxidant properties of SMe1EC2 foundin vitrowere partly confirmedin vivo.Administration of SMe1EC2 protected endothelial function. It significantly decreased endothelaemia of diabetic rats and improved endothelium-dependent relaxation of arteries, slightly decreased ROS-production and increased bioavailability of ·NO in the aorta. Further studies with higher doses of SMe1EC2 may clarify the mechanism of its endothelium-protective effectin vivo.


2018 ◽  
Vol 115 (39) ◽  
pp. 9779-9784 ◽  
Author(s):  
Sangeeta Tiwari ◽  
Andries J. van Tonder ◽  
Catherine Vilchèze ◽  
Vitor Mendes ◽  
Sherine E. Thomas ◽  
...  

Reactive oxygen species (ROS)-mediated oxidative stress and DNA damage have recently been recognized as contributing to the efficacy of most bactericidal antibiotics, irrespective of their primary macromolecular targets. Inhibitors of targets involved in both combating oxidative stress as well as being required for in vivo survival may exhibit powerful synergistic action. This study demonstrates that the de novo arginine biosynthetic pathway in Mycobacterium tuberculosis (Mtb) is up-regulated in the early response to the oxidative stress-elevating agent isoniazid or vitamin C. Arginine deprivation rapidly sterilizes the Mtb de novo arginine biosynthesis pathway mutants ΔargB and ΔargF without the emergence of suppressor mutants in vitro as well as in vivo. Transcriptomic and flow cytometry studies of arginine-deprived Mtb have indicated accumulation of ROS and extensive DNA damage. Metabolomics studies following arginine deprivation have revealed that these cells experienced depletion of antioxidant thiols and accumulation of the upstream metabolite substrate of ArgB or ArgF enzymes. ΔargB and ΔargF were unable to scavenge host arginine and were quickly cleared from both immunocompetent and immunocompromised mice. In summary, our investigation revealed in vivo essentiality of the de novo arginine biosynthesis pathway for Mtb and a promising drug target space for combating tuberculosis.


2015 ◽  
Vol 17 ◽  
pp. 380-387 ◽  
Author(s):  
Diana Dumitriu ◽  
Rafael A. Peinado ◽  
José Peinado ◽  
Nieves López de Lerma

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 504 ◽  
Author(s):  
Hainan Sun ◽  
Xiaoling Wang ◽  
Shumei Zhai

Radiotherapy (RT) has been widely used for cancer treatment. However, the intrinsic drawbacks of RT, such as radiotoxicity in normal tissues and tumor radioresistance, promoted the development of radiosensitizers. To date, various kinds of nanoparticles have been found to act as radiosensitizers in cancer radiotherapy. This review focuses on the current state of nanoradiosensitizers, especially the related biological mechanisms, and the key design strategies for generating nanoradiosensitizers. The regulation of oxidative stress, DNA damage, the cell cycle, autophagy and apoptosis by nanoradiosensitizers in vitro and in vivo is highlighted, which may guide the rational design of therapeutics for tumor radiosensitization.


2020 ◽  
Vol 287 (1918) ◽  
pp. 20191917 ◽  
Author(s):  
Javier Pineda-Pampliega ◽  
Amparo Herrera-Dueñas ◽  
Ellis Mulder ◽  
José I. Aguirre ◽  
Ursula Höfle ◽  
...  

Telomere length (TL) and shortening is increasingly shown to predict variation in survival and lifespan, raising the question of what causes variation in these traits. Oxidative stress is well known to accelerate telomere attrition in vitro , but its importance in vivo is largely hypothetical. We tested this hypothesis experimentally by supplementing white stork ( Ciconia ciconia ) chicks with antioxidants. Individuals received either a control treatment, or a supply of tocopherol (vitamin E) and selenium, which both have antioxidant properties. The antioxidant treatment increased the concentration of tocopherol for up to two weeks after treatment but did not affect growth. Using the telomere restriction fragment technique, we evaluated erythrocyte TL and its dynamics. Telomeres shortened significantly over the 21 days between the baseline and final sample, independent of sex, mass, size and hatching order. The antioxidant treatment significantly mitigated shortening rate of average TL (−31% in shorter telomeres; percentiles 10th, 20th and 30th). Thus, our results support the hypothesis that oxidative stress shortens telomeres in vivo .


2010 ◽  
Vol 30 (11) ◽  
pp. 2681-2692 ◽  
Author(s):  
Nilotpal Roy ◽  
Tanya Stoyanova ◽  
Carmen Dominguez-Brauer ◽  
Hyun Jung Park ◽  
Srilata Bagchi ◽  
...  

ABSTRACT Reactive oxygen species (ROS) is critical for premature senescence, a process significant in tumor suppression and cancer therapy. Here, we reveal a novel function of the nucleotide excision repair protein DDB2 in the accumulation of ROS in a manner that is essential for premature senescence. DDB2-deficient cells fail to undergo premature senescence induced by culture shock, exogenous oxidative stress, oncogenic stress, or DNA damage. These cells do not accumulate ROS following DNA damage. The lack of ROS accumulation in DDB2 deficiency results from high-level expression of the antioxidant genes in vitro and in vivo. DDB2 represses antioxidant genes by recruiting Cul4A and Suv39h and by increasing histone-H3K9 trimethylation. Moreover, expression of DDB2 also is induced by ROS. Together, our results show that, upon oxidative stress, DDB2 functions in a positive feedback loop by repressing the antioxidant genes to cause persistent accumulation of ROS and induce premature senescence.


2006 ◽  
Vol 74 (12) ◽  
pp. 6839-6846 ◽  
Author(s):  
Ge Wang ◽  
Yang Hong ◽  
Adriana Olczak ◽  
Susan E. Maier ◽  
Robert J. Maier

ABSTRACT Neutrophil-activating protein (NapA) has been well documented to play roles in human neutrophil recruitment and in stimulating host cell production of reactive oxygen intermediates (ROI). A separate role for NapA in combating oxidative stress within H. pylori was implied by studies of various H. pylori mutant strains. Here, physiological analysis of a napA strain was the approach used to assess the iron-sequestering and stress resistance roles of NapA, its role in preventing oxidative DNA damage, and its importance to mouse colonization. The napA strain was more sensitive to oxidative stress reagents and to oxygen, and it contained fourfold more intracellular free iron and more damaged DNA than the parent strain. Pure, iron-loaded NapA bound to DNA, but native NapA did not, presumably linking iron levels sensed by NapA to DNA damage protection. Despite its in vitro phenotype of sensitivity to oxidative stress, the napA strain showed normal (like that of the wild type) mouse colonization efficiency in the conventional in vivo assay. By use of a modified mouse inoculation protocol whereby nonviable H. pylori is first inoculated into mice, followed by (live) bacterial strain administration, an in vivo role for NapA in colonization efficiency could be demonstrated. NapA is the critical component responsible for inducing host-mediated ROI production, thus inhibiting colonization by the napA strain. An animal colonization experiment with a mixed-strain infection protocol further demonstrated that the napA strain has significantly decreased ability to survive when competing with the wild type. H. pylori NapA has unique and separate roles in gastric pathogenesis.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Fujie Yan ◽  
Yushu Chen ◽  
Ramila Azat ◽  
Xiaodong Zheng

Mulberry anthocyanins possess many pharmacological effects including liver protection, anti-inflammation, and anticancer. The aim of this study was to evaluate whether mulberry anthocyanin extract (MAE) exerts beneficial effects against oxidative stress damage in HepG2 cells and Caenorhabditis elegans. In vitro, MAE prevented cytotoxicity, increased glucose consumption and uptake, and eliminated excessive intracellular free radicals in H2O2-induced cells. Moreover, MAE pretreatment maintained Nrf2, HO-1, and p38 MAPK stimulation and abolished upregulation of p-JNK, FOXO1, and PGC-1α that were involved in oxidative stress and insulin signalling modulation. In vivo, extended lifespan was observed in C. elegans damaged by paraquat in the presence of MAE, while these beneficial effects were disappeared in pmk-1 and daf-16 mutants. PMK-1 and SKN-1 were activated after exposure to paraquat and MAE suppressed PMK-1 activation but enhanced SKN-1 stimulation. Our findings suggested that MAE recovered redox status in HepG2 cells and C. elegans that suffered from oxidative stress, which might be by targeting MAPKs and Nrf2.


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