scholarly journals Hydroxycinnamic Acid Antioxidants: An Electrochemical Overview

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
José Teixeira ◽  
Alexandra Gaspar ◽  
E. Manuela Garrido ◽  
Jorge Garrido ◽  
Fernanda Borges
Keyword(s):  
Rational Design ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Phenoxyl Radical ◽  
Free Radical Scavenger ◽  
Hydroxycinnamic Acid ◽  
Hydroxycinnamic Acids ◽  
Radical Scavenger ◽  
Redox Potentials ◽  
Structure Property

Hydroxycinnamic acids (such as ferulic, caffeic, sinapic, andp-coumaric acids) are a group of compounds highly abundant in food that may account for about one-third of the phenolic compounds in our diet. Hydroxycinnamic acids have gained an increasing interest in health because they are known to be potent antioxidants. These compounds have been described as chain-breaking antioxidants acting through radical scavenging activity, that is related to their hydrogen or electron donating capacity and to the ability to delocalize/stabilize the resulting phenoxyl radical within their structure. The free radical scavenger ability of antioxidants can be predicted from standard one-electron potentials. Thus, voltammetric methods have often been applied to characterize a diversity of natural and synthetic antioxidants essentially to get an insight into their mechanism and also as an important tool for the rational design of new and potent antioxidants. The structure-property-activity relationships (SPARs) correlations already established for this type of compounds suggest that redox potentials could be considered a good measure of antioxidant activity and an accurate guideline on the drug discovery and development process. Due to its magnitude in the antioxidant field, the electrochemistry of hydroxycinnamic acid-based antioxidants is reviewed highlighting the structure-property-activity relationships (SPARs) obtained so far.

Structure-Radical Scavenging Activity Relationships of Flavonoids from Ziziphus and Hydrangea Extracts

2008 ◽  
Vol 59 (3) ◽  
pp. 309-313 ◽  
Author(s):  
Alfa Xenia Lupea ◽  
Mariana Pop ◽  
Svetlana Cacig
Keyword(s):  
Antioxidant Activity ◽  
Structural Characteristics ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Hydroxyl Groups ◽  
Substitution Pattern ◽  
Free Hydroxyl ◽  
The Relationship

Methanol extracts prepared from Ziziphus and Hydrangea fruits and leaves were examined for their antioxidant activity. Antioxidative activities were studied in sunflower oil at 980C, by measuring peroxide value, and with the spectrophotometric method, which uses 1, 1 diphenyl-2-picrylhydrazyl (DPPH) free radicals. The relationship between the structural characteristics of pure four flavonoids and their antioxidant activity was also studied. The obtained results suggest that the free radical scavenger potential of these polyphenolic compounds closely depends on the particular substitution pattern of free hydroxyl groups on the flavonoid skeleton.

DPPH Free Radical Scavenger Components from the Fruits of Alpinia rafflesiana Wall. ex. Bak. (Zingiberaceae)

2004 ◽  
Vol 59 (11-12) ◽  
pp. 811-815 ◽  
Author(s):  
Habsah Mohamad ◽  
Faridah Abas ◽  
Dharma Permana ◽  
Nordin H. Lajis ◽  
Abdul Manaf Ali ◽  
...  
Keyword(s):  
Free Radical ◽  
Methanol Extract ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Scavenging Activity ◽  
Colorimetric Analysis ◽  
Natural Sources

The methanol extract of the dried ripe fruits of Alpinia rafflesiana was investigated for its DPPH free radical scavenger constituents. 2′,3′,4′,6′-Tetrahydroxychalcone (7), which has never been isolated from natural sources was found to be most active as a DPPH free radical scavenger with the IC50 value of 55 μᴍ. Other known compounds isolated from this species include 5,6-dehydrokawain (1), flavokawin B (2), 1,7-diphenyl-5-hydroxy-6-hepten-3-one (3), (-)-pinocembrin (4), cardamonin (5) and (-)-pinostrobin (6). The DPPH free radical scavenger compounds were detected using TLC autographic analysis. The percentage inhibition of DPPH free radical scavenging activity was measured on isolates (5-7) using colorimetric analysis.

scholarly journals Ilex khasiana - The silent holly species of Aquifoliaceae on its pharmacognostical importance as a free radical scavenger and antibacterial agent

2020 ◽  
Vol 11 (2) ◽  
pp. 2438-2444
Author(s):  
Charles Lalnunfela ◽  
Lalremsanga H.T. ◽  
Lalhriatpuii T.C. ◽  
Lalthanpuii P.B. ◽  
Kholhring Lalchhandama
Keyword(s):  
Free Radical ◽  
Medicinal Plant ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Northeast India ◽  
Free Radical Scavenger ◽  
Butylated Hydroxytoluene ◽  
Radical Scavenger ◽  
Endangered Medicinal Plant ◽  
Rare And Endangered

Ilex khasiana is a rare and endangered medicinal plant endemic to northeast India. Remaining largely unexplored,it is purported to have a range of medicinal values and may soon join the medicinal plant hall of fame.Extracts of the leaves were prepared using solvents of increasing polarity, namelypetroleum ether (IKP), chloroform (IKC) and methanol (IKM).The preliminary phytochemical screening indicated the presence of alkaloids, phytosterols, triterpenoids, saponins, reducing sugars, glycosides and carbohydrates. Free radical-scavenging activity was assessed using2,2-diphenyl-1-picrylhydrazyl(DPPH). IKC exhibited the highest activity with an IC50 of 17.22 ± 1.87, followed by IKM with an IC50 of 26.93 ± 5.14 and IKP with an IC50 of 37.16 ± 5.11. Butylated hydroxytoluene (BHT)was used as the standard DPPH scavenger and showed an IC50 of 8.31 ±0.72. IKM and IKC also showed positive antibacterial activity againstGram-negative bacteria such asEscherichia coli, Pseudomonas aeruginosa, andKlebsiella pneumoniae, and a Gram-positive bacteriaBacillus subtilis. IKP did not indicate any inhibition against the selected bacteria. Our findings substantiate the basis for further investigations on the medicinal potentials of the plant.  

scholarly journals EVALUATION OF ANTIOXIDANT, Α-GLUCOSIDASE AND Α-AMYLASE INHIBITORY ACTIVITIES OF ATALANTIA RACEMOSA AND SENNA UNIFLORA LEAVES

2018 ◽  
Vol 11 (5) ◽  
pp. 254
Author(s):  
Adhav Rahul ◽  
Deokule Subhash
Keyword(s):  
Ethyl Acetate ◽  
Sulfonic Acid ◽  
Ethyl Acetate Extract ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Inhibition Assay ◽  
Flavonoid Content ◽  
Inhibitory Activities

 Objective: The current investigation was conducted to investigate the total phenol, total flavonoid content, antioxidant, α-glucosidase, and α-amylase activities in leaves of Atalantia racemosa and Senna uniflora. Methods: Different crude solvent extracts were prepared and concentrated using rotary evaporator, these solvent extracts were tested to estimate the antioxidant radical scavenging activity using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2, 2’-azinobis, 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods using spectrophotometer. The extracts were screened by α-amylase inhibition assay and α-glucosidase inhibition assay to estimate the antidiabetic potential of the studied plant with the help of microplate reader.Results: A potent antioxidant activity, i.e. mean percentage inhibition of DPPH and ABTS radical was observed in A. racemosa ethanol (71.5 ± 0.026%) and ethyl acetate extract (97.3 ± 0.076%), respectively, at the concentration of 400 μg/mL. Similarly, highest α-amylase and α-glucosidase inhibitory activities were observed in A. racemosa methanolic (82.4 ± 0.016%) and ethyl acetate 91.1±0.018 extracts, respectively.Conclusions: The present study revealed that the A. racemosa extracts possessed good antioxidant, α-amylase and α-glucosidase inhibitory activities; hence, it can be used as a source of natural free radical scavenger and antidiabetic supplement(s). However, further study needs to be carried out to know the active compound and its mode of action.

A free radical scavenger but not FGF-2-mediated angiogenic therapy rescues myonephropathic metabolic syndrome in severe hindlimb ischemia

2006 ◽  
Vol 290 (4) ◽  
pp. H1484-H1492 ◽  
Author(s):  
Kazuhiro Kaneko ◽  
Yoshikazu Yonemitsu ◽  
Takaaki Fujii ◽  
Mitsuho Onimaru ◽  
Chen-Hao Jin ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Gene Transfer ◽  
Critical Limb Ischemia ◽  
Sendai Virus ◽  
Radical Scavenging ◽  
Limb Ischemia ◽  
Free Radical Scavenger ◽  
Intercellular Adhesion Molecule ◽  
Radical Scavenger ◽  
Intercellular Adhesion Molecule 1

The therapeutic use of angiogenic factors shows promise in the treatment of critical limb ischemia; however, its potential for myonephropathic metabolic syndrome (MNMS), a fatal complication caused by arterial reconstruction, has not been elucidated. The objective of this study was to evaluate the effectiveness of recombinant Sendai virus-mediated gene transfer of fibroblast growth factor-2 (FGF-2) directly compared with that of a radical scavenger, MCI-186, in a rat model of MNMS. MNMS was surgically induced by aortic occlusion below renal arteries for 4 h, followed by 6 h of reperfusion. Administration of MCI-186 (twice; iv 5 min before induced ischemia and ip 5 min before reperfusion; 10 mg/kg, respectively), but not FGF-2 gene transfer (once, 48 h before induced ischemia), dramatically prevented the increase of serum biochemical markers as well as the edema of the gastrocnemius muscle. The effect of MCI-186 was accompanied by the marked suppression of the neutrophilic infiltration into the local (muscle) and remote (lung) organs. Although serum and muscular levels of a neutrophil-chemoattractant (growth-related oncogene/cytokine-induced neutrophil chemoattractant-1) were not affected by any treatment, the serum level of soluble intercellular adhesion molecule-1 was decreased by treatment with MCI-186 but not by treatment with FGF-2. These results suggest the distinct mechanism of MNMS from critical limb ischemia without reperfusion. Therefore, radical scavenging should be paid more attention than therapeutic angiogenesis when arterial circulation is reconstructed.

scholarly journals Effects of solvent extraction system on antioxidant activity of Lamium purpureum L.

2017 ◽  
Vol 71 (5) ◽  
pp. 361-370
Author(s):  
Slavica Grujic ◽  
Ana Dzamic ◽  
Violeta Mitic ◽  
Vesna Stankov-Jovanovic ◽  
P.D. Marin ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Methanol Extract ◽  
Phenolic Content ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Total Phenolic ◽  
Radical Scavenger ◽  
Scavenging Activity

Antioxidant and free radical scavenging activity of methanol, ethanol, ethyl acetate and chloroform extracts of aerial parts of Lamium purpureum L. was determined by DPPH, ABTS, FRAP and TRP assays. Contents of flavonoids and phenols were also investigated. The total phenolic content in the extracts, determined using Folin?Ciocalteu assay, ranged between 8.57 to 128.00 mg GAE/g d.e. while concentrations of flavonoids in the extracts varied from 24.20 to 39.80 mg QuE/g d.e. The highest phenolic content was found in methanol extract (128.00 mg GAE/g d.e.). The highest content of total flavonoids was identified in the methanol extract (39.80 mg QuE/g d.e.) and the lowest was in the chloroform (24.30 mg QuE/g d.e.). DPPH scavenging of the extracts was determined and obtained IC50 values ranged from 0.12 to 3.12 mg/mL of solution. The values of ABTS radical scavenging activity ranged from 0.35 to 1.80 mg AA/g. The highest ABTS antiradical activity was registered for methanol extract. The FRAP value was found within the range 0.08 to 1.04 ?mol Fe/mg. The best radical scavenger was methanol (1.04 ?mol Fe/mg). In reducing power assay different extracts of L. purpureum showed increasing of activity with increased concentration, and all extracts possessed substantial dose dependent antioxidant activity. The best reducing capacity was obtained with methanol extract of L. purpureum (0.0132 mg AA/mL). The results in this study confirmed that L. purpureum possesses moderate antioxidant properties.

scholarly journals Flavonoid Preparations from Taraxacum officinale L. Fruits—A Phytochemical, Antioxidant and Hemostasis Studies

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5402
Author(s):  
Bernadetta Lis ◽  
Dariusz Jedrejek ◽  
Joanna Rywaniak ◽  
Agata Soluch ◽  
Anna Stochmal ◽  
...  
Keyword(s):  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Taraxacum Officinale ◽  
Hydroxycinnamic Acids ◽  
Phytochemical Analysis ◽  
New Information ◽  
Biological Potential ◽  
History Of ◽  
History Of Use

Dandelion (Taraxacum officinale L.) roots, leaves, and flowers have a long history of use in traditional medicine. Compared to the above organs, dandelion fruits are the least known and used. Hence, the present paper was aimed at the phytochemical analysis of T. officinale fruit extract and estimating its antiradical, antiplatelet, and antioxidant properties related to hemostasis. Methanolic extract of fruits (E1), enriched with polyphenols (188 mg gallic acid equivalents (GAE)/g), was successfully separated into cinnamic acids (E2; 448 mg GAE/g) and flavonoids (E3; 377 mg GAE/g) extracts. Flavonoid extract was further divided into four fractions characterized by individual content: A (luteolin fraction; 880 mg GAE/g), B (philonotisflavone fraction; 516 mg GAE/g), C (flavonolignans fraction; 384 mg GAE/g), and D (flavone aglycones fraction; 632 mg GAE/g). High DPPH radical scavenging activity was evaluated for fractions A and B (A > B > Trolox), medium for extracts (Trolox > E3 > E2 > E1), and low for fractions C and D. No simple correlation between polyphenol content and antiradical activity was observed, indicating a significant influence of qualitative factor, including higher anti-oxidative effect of flavonoids with B-ring catechol system compared to hydroxycinnamic acids. No cytotoxic effect on platelets was observed for any dandelion preparation tested. In experiments on plasma and platelets, using several different parameters (lipid peroxidation, protein carbonylation, oxidation of thiols, and platelet adhesion), the highest antioxidant and antiplatelet potential was demonstrated by three fruit preparations–hydroxycinnamic acids extract (E2), flavonoid extract (E3), and luteolin fraction (A). The results of this paper provide new information on dandelion metabolites, as well as their biological potential and possible use concerning cardiovascular diseases.

scholarly journals Synthesis and Investigations on Antioxidant Behaviour of Chromone Based Semicarbazones

2018 ◽  
Vol 34 (6) ◽  
pp. 3095-3099
Author(s):  
Gurpinder Singh ◽  
Kritika Thakur
Keyword(s):  
Antioxidant Activity ◽  
Good Yield ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Radical Scavenger ◽  
Scavenging Activity ◽  
Electronegative Atom ◽  
Activity Behaviour

Chromone derived carbazones provide an important antioxidant activity by exhibiting radical scavenging action, Semicarbazones are synthesized in good yield and these act as a good radical scavenger, where the presence of various substituent at C-6 of chromone nucleus tend to alter the activity behaviour, presence of electronegative atom such as fluoro/ chloro enhances the radical scavenging activity in comparison to electron donating group.

scholarly journals The Metabolite Urolithin-A Ameliorates Oxidative Stress in Neuro-2a Cells, Becoming a Potential Neuroprotective Agent

Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 177 ◽  
Author(s):  
Guillermo Cásedas ◽  
Francisco Les ◽  
Carmen Choya-Foces ◽  
Martín Hugo ◽  
Víctor López
Keyword(s):  
Oxidative Stress ◽  
Enzyme Inhibitor ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Monoamine Oxidase A ◽  
Mitochondrial Activity ◽  
Radical Scavenger ◽  
Dependent Manner ◽  
Urolithin A ◽  
Ic50 Values

Urolithin A is a metabolite generated from ellagic acid and ellagitannins by the intestinal microbiota after consumption of fruits such as pomegranates or strawberries. The objective of this study was to determine the cytoprotective capacity of this polyphenol in Neuro-2a cells subjected to oxidative stress, as well as its direct radical scavenging activity and properties as an inhibitor of oxidases. Cells treated with this compound and H2O2 showed a greater response to oxidative stress than cells only treated with H2O2, as mitochondrial activity (MTT assay), redox state (ROS formation, lipid peroxidation), and the activity of antioxidant enzymes (CAT: catalase, SOD: superoxide dismutase, GR: glutathione reductase, GPx: glutathione peroxidase) were significantly ameliorated; additionally, urolithin A enhanced the expression of cytoprotective peroxiredoxins 1 and 3. Urolithin A also acted as a direct radical scavenger, showing values of 13.2 μM Trolox Equivalents for Oxygen Radical Absorbance Capacity (ORAC) and 5.01 µM and 152.66 µM IC50 values for superoxide and 2,2-diphenyss1-picrylhydrazyl (DPPH) radicals, respectively. Finally, inhibition of oxidizing enzymes, such as monoamine oxidase A and tyrosinase, was also detected in a dose-dependent manner. The cytoprotective effects of urolithin A could be attributed to the improvement of the cellular antioxidant battery, but also to its role as a direct radical scavenger and enzyme inhibitor of oxidases.

scholarly journals Free Radical–Mediated Cell Damage After Experimental Status Epilepticus in Hippocampal Slice Cultures

2002 ◽  
Vol 88 (6) ◽  
pp. 2909-2918 ◽  
Author(s):  
Richard Kovács ◽  
Sebastian Schuchmann ◽  
Siegrun Gabriel ◽  
Oliver Kann ◽  
Julianna Kardos ◽  
...  
Keyword(s):  
Free Radicals ◽  
Status Epilepticus ◽  
Free Radical ◽  
Hippocampal Slice ◽  
Cell Damage ◽  
Radical Scavenging ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Mitochondrial Depolarization ◽  
Hippocampal Slice Cultures

Generation of free radicals may have a key role in the nerve cell damage induced by prolonged or frequently recurring convulsions (status epilepticus). Mitochondrial function may also be altered due to production of free radicals during seizures. We therefore studied changes in field potentials (fp) together with measurements of extracellular, intracellular, and intramitochondrial calcium concentration ([Ca2+]e, [Ca2+]i, and [Ca2+]m, respectively), mitochondrial membrane potential (ΔΨ), NAD(P)H auto-fluorescence, and dihydroethidium (HEt) fluorescence in hippocampal slice cultures by means of simultaneous electrophysiological and microfluorimetric measurements. As reported previously, each seizure-like event (SLE) resulted in mitochondrial depolarization associated with a delayed rise in oxidation of HEt to ethidum, presumably indicating ROS production. We show here that repeated SLEs led to a decline in intracellular and intramitochondrial Ca2+ signals despite unaltered Ca2+ influx. Also, mitochondrial depolarization and the NAD(P)H signal became smaller during recurring SLEs. By contrast, the ethidium fluorescence rises remained constant or even increased from SLE to SLE. After about 15 SLEs, activity changed to continuous afterdischarges with steady depolarization of mitochondrial membranes. Staining with a cell death marker, propidium iodide, indicated widespread cell damage after 2 h of recurring SLEs. The free radical scavenger, α-tocopherol, protected the slice cultures against this damage and also reduced the ongoing impairment of NAD(P)H production. These findings suggest involvement of reactive oxygen species (ROS) of mitochondrial origin in the epileptic cell damage and that free radical scavenging may prevent status epilepticus–induced cell loss.

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