Antioxidants

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Open AccessReview

Which Is the Most Significant Cause of Aging?

by Stefan I. Liochev

Antioxidants 2015, 4(4), 793-810; https://doi.org/10.3390/antiox4040793 - 17 Dec 2015

Cited by 36 | Viewed by 9118

It becomes clearer and clearer that aging is a result of a significant number of causes and it would seem that counteracting one or several of them should not make a significant difference. Taken at face value, this suggests, for example, that free [...] Read more.

It becomes clearer and clearer that aging is a result of a significant number of causes and it would seem that counteracting one or several of them should not make a significant difference. Taken at face value, this suggests, for example, that free radicals and reactive oxygen species do not play a significant role in aging and that the lifespan of organisms cannot be significantly extended. In this review, I point to the fact that the causes of aging synergize with each other and discuss the implications involved. One implication is that when two or more synergizing causes increase over time, the result of their action increases dramatically; I discuss a simple model demonstrating this. It is reasonable to conclude that this might explain the acceleration of aging and mortality with age. In this regard, the analysis of results and mortality patterns described in studies involving yeasts and Drosophila provides support for this view. Since the causes of aging are synergizing, it is also concluded that none of them is the major one but many including free radicals, etc. play significant roles. It follows that health/lifespan might be significantly extended if we eliminate or even attenuate the increase of a few or even just one of the causes of aging. While the synergism between the causes of aging is the main topic of this review, several related matters are briefly discussed as well. Full article

(This article belongs to the Special Issue Oxidative Stress and Aging: Past, Present and Future Concepts)

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1353 KiB

Open AccessArticle

Testing the Effects of DL-Alpha-Tocopherol Supplementation on Oxidative Damage, Total Antioxidant Protection and the Sex-Specific Responses of Reproductive Effort and Lifespan to Dietary Manipulation in Australian Field Crickets (Teleogryllus commodus)

by C. Ruth Archer, Sarah Hempenstall, Nick J. Royle, Colin Selman, Sheridan Willis, James Rapkin, Jon D. Blount and John Hunt

Antioxidants 2015, 4(4), 768-792; https://doi.org/10.3390/antiox4040768 - 04 Dec 2015

Cited by 14 | Viewed by 5907

Abstract

The oxidative stress theory predicts that the accumulation of oxidative damage causes aging. More generally, oxidative damage could be a cost of reproduction that reduces survival. Both of these hypotheses have mixed empirical support. To better understand the life-history consequences of oxidative damage, [...] Read more.

The oxidative stress theory predicts that the accumulation of oxidative damage causes aging. More generally, oxidative damage could be a cost of reproduction that reduces survival. Both of these hypotheses have mixed empirical support. To better understand the life-history consequences of oxidative damage, we fed male and female Australian field crickets (Teleogryllus commodus) four diets differing in their protein and carbohydrate content, which have sex-specific effects on reproductive effort and lifespan. We supplemented half of these crickets with the vitamin E isoform DL-alpha-tocopherol and measured the effects of nutrient intake on lifespan, reproduction, oxidative damage and antioxidant protection. We found a clear trade-off between reproductive effort and lifespan in females but not in males. In direct contrast to the oxidative stress theory, crickets fed diets that improved their lifespan had high levels of oxidative damage to proteins. Supplementation with DL-alpha-tocopherol did not significantly improve lifespan or reproductive effort. However, males fed diets that increased their reproductive investment experienced high oxidative damage to proteins. While this suggests that male reproductive effort could elevate oxidative damage, this was not associated with reduced male survival. Overall, these results provide little evidence that oxidative damage plays a central role in mediating life-history trade-offs in T. commodus. Full article

(This article belongs to the Special Issue Oxidative Stress and Aging: Past, Present and Future Concepts)

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Open AccessArticle

Synthesis and Evaluation of the Anti-Oxidant Capacity of Curcumin Glucuronides, the Major Curcumin Metabolites

by Ambar K. Choudhury, Suganya Raja, Sanjata Mahapatra, Kalyanam Nagabhushanam and Muhammed Majeed

Antioxidants 2015, 4(4), 750-767; https://doi.org/10.3390/antiox4040750 - 02 Dec 2015

Cited by 42 | Viewed by 11694

Abstract

Curcumin metabolites namely curcumin monoglucuronide and curcumin diglucuronide were synthesized using an alternative synthetic approach. The anti-oxidant potential of these curcumin glucuronides was compared with that of curcumin using DPPH scavenging method and Oxygen Radical Absorbance Capacity (ORAC) assay. The results show that [...] Read more.

Curcumin metabolites namely curcumin monoglucuronide and curcumin diglucuronide were synthesized using an alternative synthetic approach. The anti-oxidant potential of these curcumin glucuronides was compared with that of curcumin using DPPH scavenging method and Oxygen Radical Absorbance Capacity (ORAC) assay. The results show that curcumin monoglucuronide exhibits 10 fold less anti-oxidant activity (DPPH method) and the anti-oxidant capacity of curcumin diglucuronide is highly attenuated compared to the anti-oxidant activity of curcumin. Full article

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558 KiB

Open AccessArticle

Antioxidant White Grape Seed Phenolics: Pressurized Liquid Extracts from Different Varieties

by Carmen Garcia-Jares, Alberto Vazquez, Juan P. Lamas, Marta Pajaro, Marta Alvarez-Casas and Marta Lores

Antioxidants 2015, 4(4), 737-749; https://doi.org/10.3390/antiox4040737 - 19 Nov 2015

Cited by 36 | Viewed by 6000

Abstract

Grape seeds represent a high percentage (20% to 26%) of the grape marc obtained as a byproduct from white winemaking and keep a vast proportion of grape polyphenols. In this study, seeds obtained from 11 monovarietal white grape marcs cultivated in Northwestern Spain [...] Read more.

Grape seeds represent a high percentage (20% to 26%) of the grape marc obtained as a byproduct from white winemaking and keep a vast proportion of grape polyphenols. In this study, seeds obtained from 11 monovarietal white grape marcs cultivated in Northwestern Spain have been analyzed in order to characterize their polyphenolic content and antioxidant activity. Seeds of native (Albariño, Caiño, Godello, Loureiro, Torrontés, and Treixadura) and non-native (Chardonnay, Gewurtzträminer, Pinot blanc, Pinot gris, and Riesling) grape varieties have been considered. Low weight phenolics have been extracted by means of pressurized liquid extraction (PLE) and further analyzed by LC-MS/MS. The results showed that PLE extracts, whatever the grape variety of origin, contained large amounts of polyphenols and high antioxidant activity. Differences in the varietal polyphenolic profiles were found, so a selective exploitation of seeds might be possible. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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561 KiB

Open AccessReview

The Mediterranean Lifestyle as a Non-Pharmacological and Natural Antioxidant for Healthy Aging

by Kyriazoula Chatzianagnostou, Serena Del Turco, Alessandro Pingitore, Laura Sabatino and Cristina Vassalle

Antioxidants 2015, 4(4), 719-736; https://doi.org/10.3390/antiox4040719 - 12 Nov 2015

Cited by 46 | Viewed by 10188

Abstract

Oxidative stress has been suggested to affect age-associated physiological dysfunction. Therefore, it is speculated that antioxidant supplements could have a potential role in preventing age-related diseases and death. Among different dietary habits, the highly antioxidant Mediterranean dietary pattern, which includes high vegetable and [...] Read more.

Oxidative stress has been suggested to affect age-associated physiological dysfunction. Therefore, it is speculated that antioxidant supplements could have a potential role in preventing age-related diseases and death. Among different dietary habits, the highly antioxidant Mediterranean dietary pattern, which includes high vegetable and fruit intake, consumption of legumes, cereals, and fish, low intake of meat and dairy derivatives, moderate red wine consumption, and use of extra-virgin olive oil, is characterized by other aspects than food, such as conviviality, sensory stimulation, socialization, biodiversity, and seasonality that can reinforce the Mediterranean diet’s (MeD) beneficial effects on wellbeing, quality of life, and healthy aging. The present review aims to discuss available data on the relationship between oxidative stress and aging, biomarkers of oxidative stress status, protective effects of the MeD, and the adoption of the Mediterranean lifestyle as a non-pharmacological and natural tool to cope with oxidative stress damage for a longer life span, and—even more important—healthy aging beyond the biological, psychological, and social challenges that old age entails. Full article

(This article belongs to the Special Issue Oxidative Stress and Aging: Past, Present and Future Concepts)

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1785 KiB

Open AccessArticle

Optimization of Aqueous Extraction Conditions for Recovery of Phenolic Content and Antioxidant Properties from Macadamia (Macadamia tetraphylla) Skin Waste

by Adriana Dailey and Quan V. Vuong

Antioxidants 2015, 4(4), 699-718; https://doi.org/10.3390/antiox4040699 - 12 Nov 2015

Cited by 26 | Viewed by 6227

Abstract

The macadamia is native to Australia and is now grown commercially around the world. Macadamia skin, known as waste, has been generated abundantly, but this ample source has had limited uses as a byproduct. The aim of this study was to develop optimal [...] Read more.

The macadamia is native to Australia and is now grown commercially around the world. Macadamia skin, known as waste, has been generated abundantly, but this ample source has had limited uses as a byproduct. The aim of this study was to develop optimal aqueous extraction conditions for the recovery of phenolic compounds and antioxidant properties from macadamia skin using Response Surface Methodology (RSM). Water was selected for optimizing the extraction conditions because it is a cheap, safe, and environmentally friendly solvent. The results showed that the RSM models were reliable for the prediction and evaluation of the tested variables. Within the tested ranges, temperature (°C), time (min), and sample-to-solvent ratio (g/100 mL), and their interactions, did not significantly affect phenolic compound (TPC), flavonoid, proanthocyanidin, CUPRAC, and FRAP contents. However, the time and the sample-to-solvent ratio significantly affected DPPH antioxidant activity and the ratio significantly affected ABTS antioxidant capacity. The optimal extraction conditions for the recovery of phenolic compounds and antioxidant properties were predicted and validated at a temperature of 90 °C, a time of 20 min, and a sample-to-solvent ratio of 5 g/100 mL. At these conditions, an extract with TPC of 86 mg GAE/g, flavonoids of 30 mg RUE/g, and proanthocyanidins of 97 mg CAE/g could be prepared with potent antioxidant capacity. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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Open AccessReview

Olive Tree (Olea europeae L.) Leaves: Importance and Advances in the Analysis of Phenolic Compounds

by Leila Abaza, Amani Taamalli, Houda Nsir and Mokhtar Zarrouk

Antioxidants 2015, 4(4), 682-698; https://doi.org/10.3390/antiox4040682 - 03 Nov 2015

Cited by 84 | Viewed by 10134

Abstract

Phenolic compounds are becoming increasingly popular because of their potential role in contributing to human health. Experimental evidence obtained from human and animal studies demonstrate that phenolic compounds from Olea europaea leaves have biological activities which may be important in the reduction in [...] Read more.

Phenolic compounds are becoming increasingly popular because of their potential role in contributing to human health. Experimental evidence obtained from human and animal studies demonstrate that phenolic compounds from Olea europaea leaves have biological activities which may be important in the reduction in risk and severity of certain chronic diseases. Therefore, an accurate profiling of phenolics is a crucial issue. In this article, we present a review work on current treatment and analytical methods used to extract, identify, and/or quantify phenolic compounds in olive leaves. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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16 KiB

Open AccessErratum

Erratum: Hunaefi, D., et al. The Effect of Lactobacillus plantarum ATCC 8014 and Lactobacillus acidophilus NCFM Fermentation on Antioxidant Properties of Selected in Vitro Sprout Culture of Orthosiphon aristatus (Java Tea) as a Model Study. Antioxidants 2012, 1, 4–32

by Antioxidants Editorial Office

Antioxidants 2015, 4(4), 681; https://doi.org/10.3390/antiox4040681 - 29 Oct 2015

Viewed by 3306

Abstract

Article [1] was published on 26 September 2012. In order to update the spelling of the second author’s name—“Divine N. Akumo” was written as “Divine Akumo”, it was updated a few days after publication and prior to issue release. [...] Full article

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Open AccessArticle

Identification and Antioxidant Activity of the Extracts of Eugenia uniflora Leaves. Characterization of the Anti-Inflammatory Properties of Aqueous Extract on Diabetes Expression in an Experimental Model of Spontaneous Type 1 Diabetes (NOD Mice)

by Nayara Simon Gonzalez Schumacher, Talita Cristina Colomeu, Daniella De Figueiredo, Virginia De Campos Carvalho, Cinthia Baú Betim Cazarin, Marcelo Alexandre Prado, Laura Maria Molina Meletti and Ricardo De Lima Zollner

Antioxidants 2015, 4(4), 662-680; https://doi.org/10.3390/antiox4040662 - 09 Oct 2015

Cited by 41 | Viewed by 8580

Abstract

Medical and folklore reports suggest that Eugenia uniflora (E. uniflora) is a functional food that contains numerous compounds in its composition, with anti-inflammatory, antioxidant and anti-diabetic effects. In the present study, we investigated the best solvents (water, ethanol and methanol/acetone) for extracting [...] Read more.

Medical and folklore reports suggest that Eugenia uniflora (E. uniflora) is a functional food that contains numerous compounds in its composition, with anti-inflammatory, antioxidant and anti-diabetic effects. In the present study, we investigated the best solvents (water, ethanol and methanol/acetone) for extracting bioactive compounds of E. uniflora leaves, assessing total phenols and the antioxidant activity of the extracts by 2,2-Diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), 2,2′-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and Oxygen Radical Absorbance Capacity (ORAC) assays, identifying hydrolysable tannins and three phenolic compounds (ellagic acid, gallic acid and rutin) present in the leaves. In addition, we evaluated the incidence of diabetes, degree of insulitis, serum insulin, hepatic glutathione and tolerance test glucose in non-obese diabetic (NOD) mice. Our results suggest that the aqueous extract presents antioxidant activity and high total phenols, which were used as a type 1 diabetes mellitus (DM-1) treatment in NOD mice. We verified that the chronic consumption of aqueous extract reduces the inflammatory infiltrate index in pancreatic islets, maintaining serum insulin levels and hepatic glutathione, and reducing serum lipid peroxidation as well as the risk for diabetes. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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763 KiB

Open AccessArticle

Phytochemical, Antioxidant and Anti-Cancer Properties of Euphorbia tirucalli Methanolic and Aqueous Extracts

by Benjamin Munro, Quan V. Vuong, Anita C. Chalmers, Chloe D. Goldsmith, Michael C. Bowyer and Christopher J. Scarlett

Antioxidants 2015, 4(4), 647-661; https://doi.org/10.3390/antiox4040647 - 08 Oct 2015

Cited by 50 | Viewed by 11735

Abstract

Euphorbia tirucalli is a succulent shrub or small tree that is native to the African continent, however, it is widely cultivated across the globe due to its use in traditional medicines to treat ailments, ranging from scorpion stings to HIV. Recent studies have [...] Read more.

Euphorbia tirucalli is a succulent shrub or small tree that is native to the African continent, however, it is widely cultivated across the globe due to its use in traditional medicines to treat ailments, ranging from scorpion stings to HIV. Recent studies have identified compounds present in the latex of the plant, including a range of bi- and triterpenoids that exhibit bioactivity, including anticancer activity. This study aimed to optimize water extraction conditions for high-yield total phenolic content recovery, to prepare methanol and aqueous extracts from the aerial sections of the plant, and to test the phytochemical, antioxidant, and anti-cancer properties of these extracts. Water extraction of total phenolic compounds (TPC) was optimized across a range of parameters including temperature, extraction time, and plant mass-to-solvent ratio. The water extract of the E. tirucalli powder was found to contain TPC of 34.01 mg GAE (gallic acid equivalents)/g, which was approximately half that of the methanol extract (77.33 mg GAE/g). The results of antioxidant assays showed a uniform trend, with the methanol extract’s antioxidant reducing activity exceeding that of water extracts, typically by a factor of 2:1. Regression analysis of the antioxidant assays showed the strongest correlation between extract TPC and antioxidant activity for the ABTS (2,2-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) methods. The methanol extract also showed greater growth inhibition capacity towards the MiaPaCa-2 pancreatic cancer cell line. These data suggest that further investigations are required to confirm the source of activity within the E. tirucalli leaf and stems for potential use in the nutraceutical and pharmaceutical industries. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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Antioxidants, Volume 4, Issue 4 (December 2015) – 10 articles , Pages 647-810

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