Reactive Oxygen Species, Lipid Peroxidation and Antioxidative Defense Mechanism

Lipid peroxidation can be defined as the oxidative deterioration of lipids containing any number of carbon-carbon double bonds. Lipid peroxidation is a well-established mechanism of cellular injury in both plants and animals, and is used as an indicator of oxidative stress in cells and tissues. Lipid peroxides are unstable and decompose to form a complex series of compounds including reactive carbonyl compounds. The oxidation of linoleates and cholesterol is discussed in some detail. Analytical methods for studying lipid peroxidation were mentioned. Various kinds of antioxidants with different functions inhibit lipid peroxidation and the deleterious effects caused by the lipid peroxidation products

Synergistic Antioxidant Scavenging Activities of Grape Seed and Green Tea Extracts against Oxidative Stress

Grape seed and green tea extracts are reported to produce antioxidant scavenging activities against free radical toxicity. This study aimed to investigate the hypothesis that a specific combination of these extracts presents a synergistic antioxidant scavenging activities. The extracts of grape seed, green tea and their mixtures were characterized by phytochemical studies and tested for phenolics and flavonoids. In vitro antioxidant activity for individual extract and its mixtures was determined by DPPH, hydroxyl and superoxide free radical scavenging methods. The amount of total phenolics varied among the different extracts and ranged from 43.74 to 67.68 mg of gallic acid equivalents (GAE) / g dry weight, whereas total flavonoids content ranged from 4.25 to 11.66 mg of quercetin equivalents (QU) /g dry weight. The present results suggest that both extracts reported a highly contents of total phenolic and flavonoids compounds, also the mixtures of these extracts can synergistically enhance antioxidant activity. Antioxidant potential from mixture 2 (grape seed extract 200 mg: green tea extract 100 mg) was comparable to that of standard. HPLC results showed that the most abundant components in the mixture 2 extract were epigallocatechingallate while the lowest was the procyanidine

Effect of Fe Deficiency on Antioxidant System in Leaves of Three Flax Cultivars

The potential role of antioxidant enzymes as well as antioxidant compounds in protecting plant from the deleterious effect of iron deficiency was examined in different flax Linum usitassimum L. cultivars. Three flax cultivars (Sakha 1, Sakha 2 and Giza 8) were grown in water culture with (Fe-sufficient plants, +Fe) or without (Fe-deficient plants,-Fe) iron supply for 40 days. The obtained results showed that, iron deficiency severely decreased dry weight and concentration of iron in all cultivars leaf tissue. Besides this, to verify whether iron deficiency could induce alteration in reactive oxygen species, high concentration of lipid peroxidation (TBARS) and H2O2 content in leaves of flax cultivars were detected under (-Fe) compared to (+Fe) treatments. Iron deficiency can also modulate the content of glutathione (GSH) level, which were significantly increased in Fe deficient treatment compared to Fe-sufficient treatment among cultivars. Activity of superoxide dismutase (SOD) was increased under deficient treatment. In contrast, significant differences were observed between cultivars in the activity of Fe containing enzymes such as ascorbate peroxidase (APX), peroxidase (POD) and catalase (CAT) that was greater under Fe sufficient treatment, suggesting higher amounts of physiological iron in leaf tissue of all cultivars. In addition, some changes in POD isoenzyme profile was detected under iron stress.These results suggested that, these antioxidant compounds are the key compounds to protect cell from oxidative injury

Development and emancipation: The information society and decision support systems in local authorities in Egypt.

The published version of this article can be found at Emerald publishing http://www.emeraldinsight.com/Insight/menuNavigation.do?hdAction=InsightHomePurpose – The purpose of this paper is to investigate the emancipatory promises and realities of information and communication technology (ICT) in Egypt. Design/methodology/approach – The combination of Habermasian and Foucauldian ideas implemented by a critical discourse analysis of the Egyptian Information Society Policy and interviews with employees of local decision support systems employees. Promises and rhetoric are contrasted with findings and questioned with regards to their validity. Findings – On the policy level, analysis shows that the emancipating rhetoric of ICT is not followed through. ICT is mostly seen as a means of attracting foreign direct investment. Neither political participation nor educational benefits are promoted seriously. On the local level, culture and organisational realities prevent individuals from exploiting the emancipatory potential of the technology. Originality/value – The combination of the Habermasian and Foucauldian approach exposes the problems of ICT use in developing countries. It shows that emancipation is used to legitimise ICT policies but is not taken seriously on a policy level in Egypt. Local implementations also fail to deliver on their promise. In order to have emancipatory effects, ICT policy and use will need to be reconsidered

Molecular Role of Nitric Oxide in Secondary Products Production in Ginkgo biloba Cell Suspension Culture

Effects of sodium nitroprusside (SNP; nitric oxide donor) treatment on the enhancement of secondary metabolites production, oxidative stress mediators (O2-.) accumulation and antioxidant defense enzymes of Ginkgo biloba callus culture was investigated. On one hand, the obtained data showed a highly metabolic modification of chemical constituents, PAL activity and various antioxidant defense enzymes (APX, SOD), which gradually increased in response to SNP treatments. On the other hands the high NO levels significantly increased the accumulation of various oxidative burst of O2-.. MS basal medium supplemented with casein hydrolase (500 mg/L), NAA and BA at equal concentration (0.5 mg/L) recorded the highest number of regenerated shoots (4.81 cm) and shoot height (4.96 cm) as well as root number (2.25 cm) and root length (4.5 cm). The highest survival (40 %) was shown in acclimatization on the mixture containing sand, peat moss and vermiculite (1: 1: 1, v/v/v), which significantly confirmed and reflected the variation in survival percentage. Meanwhile, higher treatment (500 μM) of NO positively enhanced secondary products accumulation of total tannins, saponins, phenols and total flavonoids in G. biloba callus culture

Effect of root-knot nematode and two species of crown gall on antioxidant activity of grape leaves

Agrobacterium tumefaciens and Agrobacterium vitis significantly reduced the entire criteria (galls, embedded stages, final population, Pf/Pi and egg production) of the root-knot nematode, Meloidogyne incognita, when they were in concomitance with grape (Vitis vinifera var) superior roots. Greater suppression in such criteria was observed with high inoculum levels (5X107 cfu/pot) than with lower (2.5X107 cfu/pot) ones. All treatments resulted in the increase of leaves contents of H2O2 and lipid peroxidation (TBARS) dramatically, which were considered the most damaging stresses in plant cells. The contents of AsA, GSH, TPH and PAL specific activity increased as a strongly antioxidant defense compound against induced oxidative damage. In addition, the increase in the activity of various antioxidant defense specific enzymes (SOD, APX, CAT and GST) represented the protective activity used to counteract the oxidative injury promoted by nematode and nematode-bacteria infections. The rate of the chemical increase was significantly higher in interaction treatments than in the leaves of plants treated singly with M. incognita. Moreover, higher inoculum levels resulted in higher values of the measured chemicals. Symptoms appearance at low levels of nematode and bacterial treatments were significantly preceded by significant induction of AsA, GSH and TPH contents, and APX, CAT, SOD, GST and PAL activities in grape leaves. However, under high levels of nematode and bacteria, an obvious depletion at all non-antioxidants enzymes’ levels and antioxidants enzymes’ activities was observed. It is supposed that stimulated antioxidative processes contributed to the suppression of necrotic symptom development in grape leaves depending on the level of pathogen inoculum.Key words: Meloidogyne incognita, grape, crown gall, Agrobacterium tumefaciens, Agrobacterium vitis,antioxidant activity

Effect of Soaking, Cooking, Germination and Fermentation Processing on Proximate Analysis and Mineral Content of Three White Sorghum Varieties (Sorghum bicolor L. Moench)

The changes in chemical composition, amylose and minerals content after soaking, cooking, germination and fermentation of three white sorghum varieties, named ‘Dorado’, ‘Shandaweel-6’, and ‘Giza-15’ were investigated. The chemical composition concluded including crude protein, oils, crude fiber and ash. Crude protein content ranged from 10.62 to 12.46% in raw sorghum. ‘Shandaweel-6’ was the highest variety in crude protein content (12.46%). ‘Dorado’ was the highest variety in oils and ash (3.91 and 1.45%). ‘Shandaweel-6’ was the highest variety in crude fiber (1.85%). Amylose content ranged from 18.30 to 20.18% in raw sorghum. Amylose was higher in ‘Giza-15’ than other varieties. Minerals content i.e., Zn, Fe, Ca, K, Na, Mg, Mn and Cu were investigated. Results indicated that raw ‘Dorado’ was the highest variety in K, Mg, Ca, Fe and Mn (264.53, 137.14, 33.09, 7.65 and 1.98 mg/100 g). While, ‘Shandaweel-6’ was the highest variety in Zn and Cu (5.02 and 0.84 mg/100 g). Finally ‘Giza-15’ was the highest variety in P and Na (381.37 and 119.29 mg/100 g). After treatments chemical composition, amylose and minerals were decreased. Processing techniques reduce the levels of antinutritional organic factors, which including phytates, phenols, tannins and enzyme inhibitors by releasing exogenous and endogenous enzymes such as phytase enzyme formed during processing

Protein Solubility, Digestibility and Fractionation after Germination of Sorghum Varieties

The changes in crude protein, free amino acids, amino acid composition, protein solubility, protein fractionation and protein digestibility after germination of sorghum were investigated. Sorghum varieties (Dorado, Shandaweel-6, Giza-15) were soaked for 20 h followed by germination for 72 h; the results revealed that crude protein and free amino acids in raw sorghum varieties ranged from 10.62 to 12.46% and 0.66 to 1.03 mg/g, respectively. Shandaweel-6 was the highest variety in crude protein and free amino acids content. After germination, crude protein was decreased and free amino acids were increased. There was an increase in content of valine and phenylalanine amino acids after germination. On the other hand, there was a decrease in most of amino acids after germination. After germination protein solubility was significantly increased. Regarding protein fractions, there was an increase in albumin, globulin and kafirin proteins and a decrease in cross linked kafirin and cross linked glutelin after germination

Variación de la composición de ácidos grasos, perfil de glucosinolatos y contenido de algunos fitoquímico en cultivos seleccionados de semillas oleaginosas de colza (Brassica napus L.)

Rapeseed (Brassica napus L.) is now the third most important source of edible oil in the world after soybean and palm oil. In this study seeds of five different rapeseed cultivars namely; pactol, silvo, topas, serw 4 and serw 6 were evaluated for their fatty acid composition, glucosinolate profile, amino acids, total tocopherols and phenolic content. Among all cultivars significant variability in fatty acids were observed. The oleic acid (C18:1) ranged from 56.31% to 58.67%, linoleic acid (C18:2) from 10.52% to 13.74%, α-linolenic acid (C18:3) from 8.83% to 10.32% and erucic acid (22:1) from 0.15% to 0.91%. The glucosinolate profile of rapeseed was also separated and identified using high-performance liquid chromatography. Small variations in the glucosinolate profile were observed among all tested cultivars; however, progoitrin and gluconapin were the major glucosinolate found. Additionally, silvo cultivar showed the highest total glucosinolate c ontents (5.97 μmol/g dw). Generally, the contents of aspartic, glutamic, arginine and leucine were high, while the contents of tyrosine and isoleucine were low among all cultivars. For total tocopherols, the results indicated that both serw 6 and pactol cultivars had the highest total tocopherol contents (138.3 and 102.8 mg/100 g oil, respectively). Total phenolic contents varied from 28.0 to 35.4 mg/g dw. The highest total phenolic content was found in topas while the lowest value was detected in serw 6. These parameters; fatty acid contents, glucosinolate profile and amino acids together with total tocopherols and phenolic contents, could be taken into consideration by oilseed rape breeders as selection criteria for developing genotypes with modified seed quality traits in Brassica napus L.La colza (Brassica napus L.) es hoy en día el tercer cultivo más importante de aceites comestibles en el mundo tras el aceite de soja y de palma. En este estudio semillas de cinco cultivos diferentes de colza, denominadas pactol, silvo, topas, serw 4 y serw 6, fueron evaluadas mediante su composición en ácidos grasos, perfil de glucosinolato, aminoácidos, tocoferoles totales y contenido fenólico. En todos los cultivos, una significativa variabilidad en los ácidos grasos fue observada. El ácido oleico (C18:1) vario desde un 56.31% a un 58.67%, ácido linoleico (C18:2) desde un 10.52% a un 13.74%, ácido α-linolenic (C18:3) desde 8.83% a un 10.32% y ácido erúcico (22:1) desde un 0.15% a un 0.91%. El perfil de glucosinolatos de colza fue también separado e identificado usando cromatografía líquida de alta eficacia. Una baja variación en el perfil de glucosinolato fue observado en todos los cultivos ensayados; sin embargo, progoitrina y gluconapina fueron los principales glucosinolatos encontraos en todos los cultivos. Además, el cultivo silvo mostro el contenido de glucosinolatos totales más alto (5.97 μmol/g dw). Generalmente, el contenido de aspártico, glutámico, arginina y leucina fue alto, mientras que el contenido de tirosina y isoleucina fue bajo en todos los cultivos. En los tocoferoles totales, los resultados indican que tanto los cultivos serw 6 y pactol tuvieron el contenido de tocoferoles más alto (138.3 and 102.8 mg/100 g de aceite, respectivamente). El contenido total de fenoles vario entre 28.0 a 35.4 mg/g peso seco. El contenido total de fenoles más alto fue encontrado en topas, mientras que el valor más bajo fue detectado en serw 6. Estos parámetros, contenido de ácidos grasos, perfil de glucosinolato y aminoácidos junto el contenido total de tocoferoles y fenoles, podrían ser tenidos en consideración por los mejoradores de semillas de colza como criterio de selección para desarrollar genotipos que modifiquen los rasgos de calidad de la Brassica napus L

Efecto de la radiación gamma sobre el perfil lipídico de los aceites de semillas de soja, cacahuete y sésamo

Seeds of soybean, peanut, and sesame were exposed to various doses of gamma irradiation (0.0, 0.5, 1.0, 2.0, 3.0, 5.0 and 7.5 kGy). Fatty acid and unsaponifiable profiles of the extracted oils were separated by gas chromatography mass spectroscopy. The results demonstrated that the ratios of unsaturated to saturated total fatty acids (TU/TS) and total hydrocarbons to sterols (TH/TSt) were significantly altered upon irradiation. These changes were clearly observed in the oil extracted from irradiated sesame seeds compared with the oils from irradiated peanuts and soybean. The major change in fatty acid composition was the decrease in the quantity of unsaturated fatty acids (C18:1 and C18:2) in all cases. In contrast, the sterol fractions such as cholesterol, campesterol, stigmasterol and β-sitosterol levels of irradiated seeds were generally lower than that of the un-irradiated seeds.Semillas de soja, cacahuete y de sésamo se expusieron a diferentes dosis de radiación gamma (0,0, 0,5, 1,0, 2,0, 3,0, 5,0 y 7,5 kGy). Se determinaron los perfiles de ácidos grasos y el insaponificable de los aceites mediante cromatografía de gases y espectrometría de masas. Los resultados demostraron que las relaciones de ácidos insaturados a ácidos grasos totales saturados (TU/TS) e hidrocarburos totales a esteroles (TH/TSt) se alteró significativamente tras la irradiación. Estos cambios se observaron claramente en el aceite extraído de las semillas de sésamo irradiados, en comparación con los aceites de soja y cacahuetes irradiados. El mayor cambio en la composición de ácidos grasos fue la disminución de la cantidad de ácidos grasos insaturados (C18:1 y C18:2) en todos los casos. En contraste, los niveles de las fracciones de esteroles como colesterol, campesterol, estigmasterol y β-sitosterol de las semillas irradiadas fueron en general más bajo que el de las semillas sin irradiados