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Antioxidants, Volume 2, Issue 3 (September 2013), Pages 77-193

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Research

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Open AccessArticle Antioxidant Potential of Bark Extracts from Boreal Forest Conifers
Antioxidants 2013, 2(3), 77-89; doi:10.3390/antiox2030077
Received: 6 May 2013 / Revised: 13 June 2013 / Accepted: 28 June 2013 / Published: 11 July 2013
Cited by 3 | PDF Full-text (438 KB) | HTML Full-text | XML Full-text
Abstract
The bark of boreal forest conifers has been traditionally used by Native Americans to treat various ailments and diseases. Some of these diseases involve reactive oxygen species (ROS) that can be prevented by the consumption of antioxidants such as phenolic compounds that [...] Read more.
The bark of boreal forest conifers has been traditionally used by Native Americans to treat various ailments and diseases. Some of these diseases involve reactive oxygen species (ROS) that can be prevented by the consumption of antioxidants such as phenolic compounds that can be found in medicinal plants. In this study, ultrasonic assisted extraction has been performed under various solvent conditions (water:ethanol mixtures) on the bark of seven boreal forest conifers used by Native Americans including: Pinus strobus, Pinus resinosa, Pinus banksiana, Picea mariana, Picea glauca, Larix laricina, and Abies balsamea. The total phenolic content, as well as ORACFL potency and cellular antioxidant activity (IC50), were evaluated for all bark extracts, and compared with the standardized water extract of Pinus maritima bark (Pycnogenol), which showed clinical efficiency to prevent ROS deleterious effects. The best overall phenolic extraction yield and antioxidant potential was obtained with Picea glauca and Picea mariana. Interestingly, total phenolic content of these bark extracts was similar to Pycnogenol but their antioxidant activity were higher. Moreover, most of the extracts did not inhibit the growth of human skin fibroblasts, WS1. A significant correlation was found between the total phenolic content and the antioxidant activity for water extracts suggesting that these compounds are involved in the activity. Full article
(This article belongs to the Special Issue Plant Antioxidants)
Open AccessArticle Antioxidant, Iron Chelating and Tyrosinase Inhibitory Activities of Extracts from Talinum triangulare Leach Stem
Antioxidants 2013, 2(3), 90-99; doi:10.3390/antiox2030090
Received: 11 May 2013 / Revised: 14 June 2013 / Accepted: 28 June 2013 / Published: 17 July 2013
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Abstract
The aim of this work is to evaluate the antioxidant activity against the radical species DPPH, the reducing capacity against Fe II ions, and the inhibitory activity on the tyrosinase enzyme of the T. triangulare. Hydromethanolic crude extract provided two fractions [...] Read more.
The aim of this work is to evaluate the antioxidant activity against the radical species DPPH, the reducing capacity against Fe II ions, and the inhibitory activity on the tyrosinase enzyme of the T. triangulare. Hydromethanolic crude extract provided two fractions after the liquid/liquid partition with chloroform. The Folin-Ciocalteu method determined the total phenolic content of the crude extract (CE) and the hydromethanolic fraction (Fraction 1), resulting in a concentration of 0.5853 g/100 g for Fraction 1, and 0.1400 g/100 g for the CE. Taking into account the results of the DPPH, the free radical scavenging capacity was confirmed. The formation of complexes with Fe II ions was evaluated by UV/visible spectrometry; results showed that CE has complexing power similar to the positive control (Gingko biloba extract).The inhibitory capacity of samples against the tyrosinase enzyme was determined by the oxidation of L-DOPA, providing IC50 values of 13.3 μg·mL−1 (CE) and 6.6 μg·mL−1 (Fraction 1). The values indicate that Fraction 1 was more active and showed a higher inhibitory power on the tyrosinase enzyme than the ascorbic acid, used as positive control. The hydromethanolic extract of T. triangulare proved to have powerful antioxidant activity and to inhibit the tyrosinase enzyme; its potential is increased after the partition with chloroform. Full article
(This article belongs to the Special Issue Plant Antioxidants)
Figures

Open AccessArticle Organic and Conventional Yerba Mate (Ilex paraguariensis A. St. Hil) Improves Metabolic Redox Status of Liver and Serum in Wistar Rats
Antioxidants 2013, 2(3), 100-109; doi:10.3390/antiox2030100
Received: 20 May 2013 / Revised: 20 June 2013 / Accepted: 12 July 2013 / Published: 24 July 2013
Cited by 1 | PDF Full-text (566 KB) | HTML Full-text | XML Full-text
Abstract
Organic and conventional yerba mate (Ilex paraguariensis) is widely used in South America to prepare nonalcoholic drinks rich in polyphenols. These compounds are able to prevent the generation of reactive species, thus minimizing the incidence of several diseases. In this [...] Read more.
Organic and conventional yerba mate (Ilex paraguariensis) is widely used in South America to prepare nonalcoholic drinks rich in polyphenols. These compounds are able to prevent the generation of reactive species, thus minimizing the incidence of several diseases. In this perspective, we hypothesized that yerba mate may have protective effects against pentylenetetrazol (PTZ)-induced oxidative damage in liver and serum of rats. Animals (n = 42) received distilled water (control) or yerba mate (organic or conventional) for fifteen days. Then, half of the rats of each group received 60 mg/kg PTZ intraperitoneally or saline solution. After 30 min the animals were euthanized and the liver and blood were collected. The results showed that organic and conventional yerba mate avoided PTZ-induced oxidative damage and nitric oxide production in the liver and serum of the rats. Moreover, both kinds of yerba mate prevented the decrease in enzymatic (superoxide dismutase and catalase) and non-enzymatic (sulfhydryl protein content) defenses in the liver and serum. In addition, histopathologic analysis of the liver showed that yerba mate reduced PTZ-induced cell damage. These findings indicate that yerba mate provides hepatoprotection and improves antioxidant status in the serum, which may contribute to the development of new therapeutic strategies using nutraceuticals drinks. Full article
(This article belongs to the Special Issue Dietary Antioxidants)
Open AccessArticle Determination of Radical Scavenging Activity and Total Phenols of Wine and Spices: A Randomized Study
Antioxidants 2013, 2(3), 110-121; doi:10.3390/antiox2030110
Received: 20 May 2013 / Revised: 20 June 2013 / Accepted: 13 July 2013 / Published: 25 July 2013
Cited by 1 | PDF Full-text (369 KB) | HTML Full-text | XML Full-text
Abstract
Thirty eight bottles of red wine (Carbanet Sauvignon) were randomly selected based on vintage, region, price, and age (number of months in a barrel). The total phenolic content of each wine was determined using Folin-Ciocalteau assay. The radical scavenging activity was evaluated [...] Read more.
Thirty eight bottles of red wine (Carbanet Sauvignon) were randomly selected based on vintage, region, price, and age (number of months in a barrel). The total phenolic content of each wine was determined using Folin-Ciocalteau assay. The radical scavenging activity was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. Apart from a few bottles that exhibited above average radical scavenging activity and phenolic content, there was no good correlation of those two quantities with region, price or vintage. The average phenolic amount was 2874 mg/L. The lowest phenolic content was found to be 1648 mg/L for an eight dollar wine. Wine with the highest amount of phenol of 4495 mg/L was a 2007, nine dollar bottle from South America. High amount of phenols did not translate into high radical scavenging activity. Barrel-aging did not increase the amount of phenols or the radical scavenging activity of wine. In order to discover new and potent sources of antioxidants from plants, the following spices were studied: ginger, cilantro, cumin, anise, linden, eucalyptus, marjoram, oregano, sage, thyme and rosemary. Whole spices were crushed and extracted for 96 h at room temperature using a combination of ethyl acetate, ethyl alcohol and water in the ratio of 4.5:4.5:1 (v/v/v). The radical scavenging activity of extracts was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. The total phenolic content of each spice was also determined using the Folin-Ciocalteau assay. Eucalyptus was found to be the most potent antioxidant with an LC50 of 324.1 mg of phenol/L, followed by marjoram with an LC50 of 407.5 mg of phenol/L, and rosemary with an LC50 of 414.0 mg/L. The least potent antioxidants were ginger and cilantro with LC50 of 7604 mg/L of phenol and 7876 mg of phenol/L, respectively. Full article
(This article belongs to the Special Issue Dietary Antioxidants)
Open AccessArticle Evaluation of Antioxidant Status of Two Limoniastrum Species Growing Wild in Tunisian Salty Lands
Antioxidants 2013, 2(3), 122-131; doi:10.3390/antiox2030122
Received: 13 June 2013 / Revised: 19 July 2013 / Accepted: 23 July 2013 / Published: 2 August 2013
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Abstract
We aim to highlight the differential antioxidant status of Limoniastrum guyonianum and Limoniastrum monopetalum in relation to their respective chemical and location characteristics. Metabolite analysis revealed similar contents in phenolic, flavonoïds, sugars and chlorophyll in the two species’ leaves. Higher amounts of [...] Read more.
We aim to highlight the differential antioxidant status of Limoniastrum guyonianum and Limoniastrum monopetalum in relation to their respective chemical and location characteristics. Metabolite analysis revealed similar contents in phenolic, flavonoïds, sugars and chlorophyll in the two species’ leaves. Higher amounts of proline (Pro), carotenoïds (Carot), sodium (Na) and potassium (K) were measured in L. monopetalum leaves relative to L. guyonianum ones. While the two Limoniastrum species have similar free radical DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity, L. guyonianum showed more than two-fold higher ferrous ions chelating activity relative to L. monopetalum. However, highest reducing power activity was observed in L. monopetalum. Thiobarbituric acid-reactive substances (TBARS) determination indicated that L. monopetalum behave better lipid membrane integrity relative to L. guyonianum. These findings suggested that the lesser stressful state of L. monopetalum was related to higher metabolites accumulation and reducing capacity compared to L. guyonianum. Full article
(This article belongs to the Special Issue Plant Antioxidants)
Open AccessCommunication Antioxidant Activity and Phenolic Content of Streblus asper Leaves from Various Drying Methods
Antioxidants 2013, 2(3), 156-166; doi:10.3390/antiox2030156
Received: 7 June 2013 / Revised: 31 July 2013 / Accepted: 23 August 2013 / Published: 30 August 2013
Cited by 4 | PDF Full-text (385 KB) | HTML Full-text | XML Full-text
Abstract
Aqueous and ethanol extracts of oven and freeze-dried Streblus asper leaves were investigated using DPPH assay. The presence of phenolic compounds and flavonoids in the extracts, which were detected by Folin and colorimetric assays, respectively, may be responsible for the antioxidant activities [...] Read more.
Aqueous and ethanol extracts of oven and freeze-dried Streblus asper leaves were investigated using DPPH assay. The presence of phenolic compounds and flavonoids in the extracts, which were detected by Folin and colorimetric assays, respectively, may be responsible for the antioxidant activities of S. asper. The different drying treatments resulted in significant differences (p < 0.05) in the antioxidant properties as well as the phenolic and flavonoid contents of the S. asper extracts. Freeze-dried S. asper leaf extracts exhibited high DPPH radical scavenging activity ranging from 69.48% ± 0.03% to 89.25% ± 0.01% at concentrations ranging from 0 to 1 mg/mL, significantly higher compared with the oven-dried extracts which were in the range of 68.56% ± 0.01% to 86.68% ± 0.01%. Generally, the 70% ethanol extract of the freeze-dried samples exhibited higher phenolic and flavonoid content than the aqueous extract, with values of 302.85 ± 0.03 mg GAE/g and 22.70 ± 0.02 mg QE/g compared with 226.8 ± 0.03 mg GAE/g and 15.38 ± 0.05 mg QE/g, respectively. This study showed that S. asper leaf extracts contain a number of health promoting bioactive compounds, such as phenolic compounds, and are potential sources of natural antioxidants. Full article
(This article belongs to the Special Issue Plant Antioxidants)
Open AccessArticle Lipophilic Constituents of Rumex vesicarius L. and Rumex dentatus L.
Antioxidants 2013, 2(3), 167-180; doi:10.3390/antiox2030167
Received: 15 July 2013 / Revised: 12 August 2013 / Accepted: 2 September 2013 / Published: 16 September 2013
Cited by 4 | PDF Full-text (1977 KB) | HTML Full-text | XML Full-text
Abstract
Rumex dentatus L. and Rumex vesicarius L., of the family Polygonaceae, are edible herbs growing wild in Egypt. Their lipoid constituents were examined by both liquid chromatography/mass spectrometry (LC/MS) and by gas chromatography/mass spectrometry (GC/MS). Their essential oil compositions consisted mainly of [...] Read more.
Rumex dentatus L. and Rumex vesicarius L., of the family Polygonaceae, are edible herbs growing wild in Egypt. Their lipoid constituents were examined by both liquid chromatography/mass spectrometry (LC/MS) and by gas chromatography/mass spectrometry (GC/MS). Their essential oil compositions consisted mainly of thujene, limonene, fenchon, estragole, and anethole but at largely different concentration. Fatty acid compositions were similar among the two species and consisting of palmitic, oleic, linoleic and linolenic acids, with R. vesicarius containing much higher level of omega-3-fatty acids. Both of the crude lipid extracts of the two species showed strong antioxidant activity as a radical quenching agent against 2,2-diphenyl-1-picrylhydrazyl (DPPH) systems. Antioxidant activities were mostly associated with the polar lipid fractions. High performance thin layer chromatography (HPTLC), both in the normal and reversed phase,as well as liquid chromatography/mass spectrometry (LC/MS) in the positive and negative electrospray ionization (ESI), showed unique chemical profile for each species that can be useful for species identification and quality control of herbal drug formulations. R. vesicarius was characterized by abundances of flavonoids and R. dentatus was abundant in anthraquinones and chromones. Full article

Review

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Open AccessReview The Antioxidants Changes in Ornamental Flowers during Development and Senescence
Antioxidants 2013, 2(3), 132-155; doi:10.3390/antiox2030132
Received: 11 July 2013 / Revised: 24 July 2013 / Accepted: 26 July 2013 / Published: 6 August 2013
Cited by 6 | PDF Full-text (307 KB) | HTML Full-text | XML Full-text
Abstract
The concentration of antioxidant compounds is constitutive and variable from species to species and is also variable considering the development of the plant tissue. In this review, we take into consideration the antioxidant changes and the physiological, biochemical and molecular factors that [...] Read more.
The concentration of antioxidant compounds is constitutive and variable from species to species and is also variable considering the development of the plant tissue. In this review, we take into consideration the antioxidant changes and the physiological, biochemical and molecular factors that are able to modulate the accumulation of antioxidant compounds in ornamental flowers during the whole development process until the senescence. Many ornamental flowers are natural sources of very important bioactive compounds with benefit to the human health and their possible role as dietary components has been reported. The most part of antioxidants are flower pigments such as carotenoids and polyphenols, often present in higher concentration compared with the most common fruits and vegetables. The antioxidants content changes during development and during senescence many biochemical systems and molecular mechanisms are activated to counteract the increase of reactive oxygen species and free radicals. There is a tight correlation between antioxidants and senescence processes and this aspect is detailed and appropriately discussed. Full article
(This article belongs to the Special Issue Plant Antioxidants)
Open AccessReview Phenolic Compounds in Apple (Malus x domestica Borkh.): Compounds Characterization and Stability during Postharvest and after Processing
Antioxidants 2013, 2(3), 181-193; doi:10.3390/antiox2030181
Received: 8 August 2013 / Revised: 3 September 2013 / Accepted: 6 September 2013 / Published: 18 September 2013
Cited by 7 | PDF Full-text (1158 KB) | HTML Full-text | XML Full-text
Abstract
This paper summarizes the information on the occurrence of phenolic compounds in apple (Malus x domestica Borkh.) fruit and juice, with special reference to their health related properties. As phytochemical molecules belonging to polyphenols are numerous, we will focus on the [...] Read more.
This paper summarizes the information on the occurrence of phenolic compounds in apple (Malus x domestica Borkh.) fruit and juice, with special reference to their health related properties. As phytochemical molecules belonging to polyphenols are numerous, we will focus on the main apples phenolic compounds with special reference to changes induced by apple cultivar, breeding approaches, fruit postharvest and transformation into juice. Full article
(This article belongs to the Special Issue Plant Antioxidants)

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