scholarly journals Comparison between In Vitro Chemical and Ex Vivo Biological Assays to Evaluate Antioxidant Capacity of Botanical Extracts

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1136
Author(s):  
Valentina Pasqualetti ◽  
Vittoria Locato ◽  
Chiara Fanali ◽  
Nadia Mulinacci ◽  
Sara Cimini ◽  
...  

The anti-oxidative activity of plant-derived extracts is well-known and confers health-promoting effects on functional foods and food supplements. Aim of this work is to evaluate the capability of two different assays to predict the real biological antioxidant efficiency. At this purpose, extracts from five different plant-derived matrices and commercial purified phytochemicals were analyzed for their anti-oxidative properties by using well-standardized in vitro chemical method (TEAC) and an ex vivo biological assay. The biological assay, a cellular membrane system obtained from erythrocytes of healthy volunteers, is based on the capability of phytochemicals treatment to prevent membrane lipid peroxidation under oxidative stress by UV-B radiation. Plant extracts naturally rich in phenols with different structure and purified phytochemicals showed different in vitro and ex vivo antioxidant capacities. A high correlation between phenolic contents of the plant-derived extracts and their ability to prevent oxidative injuries in a biological system was found, thus underlying the relevance of this class of metabolites in preventing oxidative stress. On the other hand, a low correlation between the antioxidant capacities was shown between in vitro and ex vivo antioxidant assay. Moreover, data presented in this work show how food complex matrices are more effective in preventing oxidative damages at biological level than pure phytochemicals, even if for these latter, the antioxidant activity was generally higher than that observed for food complex matrices.

2019 ◽  
Vol 133 (1) ◽  
pp. 117-134 ◽  
Author(s):  
Pamela L. Martín ◽  
Paula Ceccatto ◽  
María V. Razori ◽  
Daniel E.A. Francés ◽  
Sandra M.M. Arriaga ◽  
...  

Abstract We previously demonstrated in in vitro and ex vivo models that physiological concentrations of unconjugated bilirubin (BR) prevent oxidative stress (OS)-induced hepatocanalicular dysfunction and cholestasis. Here, we aimed to ascertain, in the whole rat, whether a similar cholestatic OS injury can be counteracted by heme oxygenase-1 (HO-1) induction that consequently elevates endogenous BR levels. This was achieved through the administration of hemin, an inducer of HO-1, the rate-limiting step in BR generation. We found that BR peaked between 6 and 8 h after hemin administration. During this time period, HO-1 induction fully prevented the pro-oxidant tert-butylhydroperoxide (tBuOOH)-induced drop in bile flow, and in the biliary excretion of bile salts and glutathione, the two main driving forces of bile flow; this was associated with preservation of the membrane localization of their respective canalicular transporters, bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2), which are otherwise endocytosed by OS. HO-1 induction counteracted the oxidation of intracellular proteins and membrane lipids induced by tBuOOH, and fully prevented the increase in the oxidized-to-total glutathione (GSHt) ratio, a sensitive parameter of hepatocellular OS. Compensatory elevations of the activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) were also prevented. We conclude that in vivo HO-1 induction protects the liver from acute oxidative injury, thus preventing consequent cholestasis. This reveals an important role for the induction of HO-1 and the consequently elevated levels of BR in preserving biliary secretory function under OS conditions, thus representing a novel therapeutic tool to limit the cholestatic injury that bears an oxidative background.


Author(s):  
Rosária Aires ◽  
Ildernandes Vieira-Alves ◽  
Leda Maria Coimbra-Campos ◽  
Marina Ladeira ◽  
Teresa Socarras ◽  
...  

BACKGROUND AND PURPOSE Acute lung injury (ALI) is a critical disorder that has high mortality rates, and pharmacological therapies are so far ineffective. The pathophysiology of ALI involves pulmonary oxidative stress and inflammatory response. Fullerol is a carbon nanocomposite that possesses antioxidant and anti-inflammatory properties. Here, we evaluated the therapeutic potential of fullerol and its mechanisms in a model of paraquat-induced ALI. EXPERIMENTAL APPROACH Rats were divided into ALI (paraquat alone), fullerol (paraquat plus fullerol), and control groups. Survival curves were estimated using the Kaplan-Meier method. The myeloperoxidase assay, ELISA, and hematoxylin and eosin staining were used to determine neutrophils infiltration, cytokines production, and histopathological parameters in lung samples, respectively. The antioxidant effect of fullerol was evaluated in vitro and ex vivo. KEY RESULTS Fullerol (0.01 to 0.3 mg/kg) markedly reduced the severe lung injury and high mortality rates observed in ALI rats. Moreover, fullerol (0.03 mg/kg) inhibited the reactive oxygen species formation and lipid peroxidation seen in lungs from ALI rats, and exhibited a potent concentration-dependent (10 to 10 mg/ml) in vitro antioxidant activity. Importantly, fullerol (0.03 mg/kg) inhibited neutrophils accumulation in bronchoalveolar lavage and lungs, and the increase in pulmonary levels of TNF-α, IL-1β, IL-6, and CINC-1 in ALI rats. CONCLUSIONS AND IMPLICATIONS Fullerol treatment was effective in reducing pulmonary damage and ALI-induced mortality, highlighting its therapeutic potential in an ALI condition. Searching for new pharmacological therapies to treat ALI may be desirable especially in view of the new coronavirus disease 2019 that currently plagues the world.


Author(s):  
Edward C. T. Waters ◽  
Friedrich Baark ◽  
Zilin Yu ◽  
Filipa Mota ◽  
Thomas R. Eykyn ◽  
...  

Abstract Purpose To determine the sensitivity of the 18F-radiolabelled dihydroethidine analogue ([18F]DHE) to ROS in a validated ex vivo model of tissue oxidative stress. Procedures The sensitivity of [18F]DHE to various ROS-generating systems was first established in vitro. Then, isolated rat hearts were perfused under constant flow, with contractile function monitored by intraventricular balloon. Cardiac uptake of infused [18F]DHE (50–150 kBq.min−1) was monitored by γ-detection, while ROS generation was invoked by menadione infusion (0, 10, or 50 μm), validated by parallel measures of cardiac oxidative stress. Results [18F]DHE was most sensitive to oxidation by superoxide and hydroxyl radicals. Normalised [18F]DHE uptake was significantly greater in menadione-treated hearts (1.44 ± 0.27) versus control (0.81 ± 0.07) (p < 0.05, n = 4/group), associated with concomitant cardiac contractile dysfunction, glutathione depletion, and PKG1α dimerisation. Conclusion [18F]DHE reports on ROS in a validated model of oxidative stress where perfusion (and tracer delivery) is unlikely to impact its pharmacokinetics.


2021 ◽  
Author(s):  
Charlotte Sarre ◽  
Rafael Contreras Lopez ◽  
Nitirut Nerpernpisooth ◽  
Christian Barrere ◽  
Sarah Bahraoui ◽  
...  

Abstract Background: Mesenchymal Stromal Cells (MSC) have been widely used for their therapeutic properties in many clinical applications including myocardial infarction. Despite promising preclinical results and evidences of safety and efficacy in phases I/ II, inconsistencies in phase III trials have been reported. In a previous study, we have shown using MSC derived from the bone marrow of PPARβ/δ (Peroxisome proliferator-activated receptors β/δ) knockout mice that the acute cardioprotective properties of MSC during the first hour of reperfusion are PPARβ/δ-dependent but not related to the anti-inflammatory effect of MSC. However, the role of the modulation of PPARβ/δ expression on MSC cardioprotective and anti-apoptotic properties has never been investigated. Objectives: The aim of this study was to investigate the role of PPARβ/δ modulation (inhibition or activation) in MSC therapeutic properties in vitro and ex vivo in an experimental model of myocardial infarction.Methods and results: Naïve MSC and MSC pharmacologically activated or inhibited for PPARβ/δ were challenged with H202. Through specific DNA fragmentation quantification and qRT-PCR experiments, we evidenced in vitro an increased resistance to oxidative stress in MSC pre-treated by the PPARβ/δ agonist GW0742 versus naïve MSC. In addition, PPARβ/δ-priming allowed to reveal the anti-apoptotic effect of MSC on co-cultured cardiomyocytes. When injected during reperfusion in an ex vivo heart model of myocardial infarction, PPARβ/δ-primed MSC at a dose of 3.75x105 MSC/heart provided the same cardioprotective efficiency than 7.5x105 naïve MSC, identified as the optimal dose in our model. These enhanced short-term cardioprotective effects were associated with an increase in both anti-apoptotic effects and the number of MSC detected in the left ventricular wall at 1 hour of reperfusion. By contrast, inhibition of PPARβ/δ before their administration in post-ischemic hearts during reperfusion decreased their cardioprotective effects. Conclusion: Altogether these results revealed that PPARβ/δ-primed MSC exhibit an increased resistance to oxidative stress and enhanced anti-apoptotic properties on cardiac cells in vitro. PPARβ/δ-priming appears as an innovative strategy to enhance the cardioprotective effects of MSC and to decrease the injected doses. These results could be of major interest to improve MSC efficacy for the cardioprotection of injured myocardium in AMI patients.


2020 ◽  
Vol 98 (2) ◽  
pp. 85-92 ◽  
Author(s):  
Mihaela Ionica ◽  
Oana M. Aburel ◽  
Adrian Vaduva ◽  
Alexandra Petrus ◽  
Sonia Rațiu ◽  
...  

Obesity is an age-independent, lifestyle-triggered, pandemic disease associated with both endothelial and visceral adipose tissue (VAT) dysfunction leading to cardiometabolic complications mediated via increased oxidative stress and persistent chronic inflammation. The purpose of the present study was to assess the oxidative stress in VAT and vascular samples and the effect of in vitro administration of vitamin D. VAT and mesenteric artery branches were harvested during abdominal surgery performed on patients referred for general surgery (n = 30) that were randomized into two subgroups: nonobese and obese. Serum levels of C-reactive protein (CRP) and vitamin D were measured. Tissue samples were treated or not with the active form of vitamin D: 1,25(OH)2D3 (100 nmol/L, 12 h). The main findings are that in obese patients, (i) a low vitamin D status was associated with increased inflammatory markers and reactive oxygen species generation in VAT and vascular samples and (ii) in vitro incubation with vitamin D alleviated oxidative stress in VAT and vascular preparations and also improved the vascular function. We report here that the serum level of vitamin D is inversely correlated with the magnitude of oxidative stress in the adipose tissue. Ex vivo treatment with active vitamin D mitigated obesity-related oxidative stress.


2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Shilpa Chakravarty ◽  
Syed Ibrahim Rizvi

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


2018 ◽  
Author(s):  
Ning-Ning Liu ◽  
Priya Uppuluri ◽  
Achille Broggi ◽  
Angelique Besold ◽  
Kicki Ryman ◽  
...  

AbstractPhosphate is an essential macronutrient required for cell growth and division. Pho84 is the major high-affinity cell-surface phosphate importer ofSaccharomyces cerevisiaeand a crucial element in the phosphate homeostatic system of this model yeast. We found that loss ofCandida albicansPho84 attenuated virulence inDrosophilaand murine oropharyngeal and disseminated models of invasive infection, and conferred hypersensitivity to neutrophil killing. Susceptibility of cells lacking Pho84 to neutrophil attack depended on reactive oxygen species (ROS):pho84-/-cells were no more susceptible than wild typeC. albicansto neutrophils from a patient with chronic granulomatous disease, or to those whose oxidative burst was pharmacologically inhibited or neutralized.pho84-/-mutants hyperactivated oxidative stress signalling. They accumulated intracellular ROS in the absence of extrinsic oxidative stress, in high as well as low ambient phosphate conditions. ROS accumulation correlated with diminished levels of the unique superoxide dismutase Sod3 inpho84-/-cells, whileSOD3overexpression from a conditional promoter substantially restored these cells’ oxidative stress resistance in vitro. Repression ofSOD3expression sharply increased their oxidative stress hypersensitivity. Neither of these oxidative stress management effects of manipulatingSOD3transcription was observed inPHO84wild type cells. Sod3 levels were not the only factor driving oxidative stress effects onpho84-/-cells, though, because overexpressingSOD3did not ameliorate these cells’ hypersensitivity to neutrophil killing ex vivo, indicating Pho84 has further roles in oxidative stress resistance and virulence. Measurement of cellular metal concentrations demonstrated that diminished Sod3 expression was not due to decreased import of its metal cofactor manganese, as predicted from the function ofS. cerevisiaePho84 as a low-affinity manganese transporter. Instead of a role of Pho84 in metal transport, we found its role in TORC1 activation to impact oxidative stress management: overexpression of the TORC1-activating GTPase Gtr1 relieved the Sod3 deficit and ROS excess inpho84-/-null mutant cells, though it did not suppress their hypersensitivity to neutrophil killing or hyphal growth defect. Pharmacologic inhibition of Pho84 by small molecules including the FDA-approved drug foscarnet also induced ROS accumulation. Inhibiting Pho84 could hence support host defenses by sensitizingC. albicansto oxidative stress.


2020 ◽  
Vol 16 (3) ◽  
pp. 284-293
Author(s):  
George Laylson da Silva Oliveira ◽  
Maria das Dores Alves de Oliveira ◽  
Maria da Conceição Oliveira Prado ◽  
Alexandre de Barros Falcão Ferraz ◽  
José Carlos Correia Lima da Silva ◽  
...  

Background: Garcinielliptone FC corresponds to a polyprenylated acylphloroglucinol having a benzophenonic core (diphenylmethanone) substituted with isoprenyl(s) group(s) (3-methyl-2-butenyl) and 2-isopropenyl-hex-5-enyl. Objective: The present work evaluated the antioxidant activity of garcinielliptone FC (GFC) in vitro against non-biological radicals [2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2'-azinobis-3- ethylbenzothiazoline-6-sulfonic acid (ABTS•+)] and ex vivo against oxidative damage induced by AAPH (2,2'-azobis-2-methylpropionamidine dihydrochloride) and iron/citrate ion in erythrocytes and mitochondria, respectively. Methods: In addition to the protective effect, the main biochemical indexes of oxidative stress, such as lipid peroxidation through the formation of Thiobarbituric Acid Reactive Substances (TBARS), Superoxide Dismutase (SOD), Catalase (CAT) activity and reduced glutathione (GSH) levels. Results: According to the results obtained in erythrocytes, the antioxidant results at concentrations of 0.1, 0.3, 0.7, 1.5 and 3.0 mM were 26.34 ± 0.68, 43.39 ± 2.17, 62.27 ± 2.17, 86.69 ± 0.47 and 92.89 ± 0.45%, respectively, where GFC reduced the rate of oxidative hemolysis when compared to AAPH (p<0.05). The antioxidant activity observed in erythrocytes was also seen in mitochondria in which GFC reduced mitochondrial swelling by increasing the absorbance when compared to iron/citrate ion complex (p<0.05). In both biological models, GFC had an antioxidant effect on erythrocyte and mitochondrial redox balance when analyzing oxidative stress biomarkers, such as reduction of lipid peroxidation and inhibition of depletion in the activity of SOD, CAT and GSH levels. Conclusion: In conclusion, GFC had in vitro and ex vivo antioxidant activity against oxidative damage induced in erythrocytes and mitochondria acting on the erythrocytic and mitochondrial redox balance.


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