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Radical Scavenging Ability (radical + scavenging_ability)
Selected AbstractsAntioxidant availability of turmeric in relation to its medicinal and culinary usesPHYTOTHERAPY RESEARCH, Issue 10 2004Jai C. Tilak Abstract Turmeric (Curcuma longa) has been used in Indian cooking, and in herbal remedies. Its possible mechanism of action was examined in terms of antioxidant availability during actual cooking conditions and in therapeutic applications using standardized extracts. The assays involve different levels of antioxidant action such as oxygen radical absorbance capacity (ORAC), radical scavenging abilities using 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2,-azobis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power (FRAP) and protection of membranes examined by inhibition of lipid peroxidation besides the content of phenols and total ,avonoids. The aqueous and ethanol extracts of two major preparations of turmeric, corresponding to its use in cooking and medicine, showed signi,cant antioxidant abilities. In conclusion, the studies reveal that the ability of turmeric to scavenge radicals, reduce iron complex and inhibit peroxidation may explain the possible mechanisms by which turmeric exhibits its bene,cial effects in relation to its use in cooking and medicine. Copyright © 2004 John Wiley & Sons, Ltd. [source] DPPH free-radical scavenging ability, total phenolic content, and chemical composition analysis of forty-five kinds of essential oilsINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 6 2009H.-F. Wang J. Cosmet. Sci., 59, 509,522 (November/December 2008) Synopsis Forty-five kinds of commonly used essential oils were employed to investigate the DPPH (1,1-diphenyl2-picrylhydrazyl) radical scavenging ability and total phenolic content of major chemical compositions. The free-radical scavenging ability and total phenolic content of cinnamon leaf and clove bud essential oils are the best among these essential oils. One-half milliliter of cinnamon leaf and clove bud essential oils (10 mg mL EtOH) are shown to be 96.74% and 96.12% of the DPPH (2.5ml, 1.52 × 10 -4 M) free-radical scavenging ability, respectively. Their EC50 (effective concentrations) are 53 and 36 (,g mL -1). One milligram per milliliter of cinnamon leaf, clove bud, and thyme red essential oils were shown to be 420, 480, and 270 (mg g -1 of GAE) of total phenolic content, respectively. Eugenol in cinnamon leaf and clove bud essential oils (82.87% and 82.32%, respectively) were analyzed by GC-MS. It is clear that the amounts of the phenol compounds in essential oils and the DPPH free-radical scavenging ability are in direct proportion. [source] The effect of roasting on the nutritional and antioxidant properties of yellow and white maize varietiesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2010Ganiyu Oboh Summary Maize varieties (yellow and white) were roasted for 17 min; and allowed to cool, and later milled into powder. The nutritional evaluation (proximate composition, mineral and antinutrient content determination) and antioxidant properties investigation (reducing power, free radicals scavenging ability and Fe2+ chelating ability) of the product was subsequently carried out. The result of the study revealed that roasting caused a significant increase (P < 0.05) in the crude fat, carbohydrate, Ca, Na, Mg and Zn content. Conversely, a significant decrease (P < 0.05) was observed in crude protein, crude fibre, Fe and K content. A significant decrease in the phytate content was also observed. However, the reduced phytate content did not have sparing effect on Zn bioavailability. Roasting significantly (P < 0.05) reduced the extractible phenol and flavonoid content of the maize varieties. The antioxidant properties (1,1-diphenyl-2-picrylhydracyl free radical scavenging ability and Fe2+ chelating ability) followed the phenolic content pattern. However, roasting caused a significant increase in the ferric reducing antioxidant power of the maize varieties. Thus, roasting reduced the protein content of maize but also increased the energy value and antioxidant capacity as exemplified by high reducing power. [source] Reinforcement and antioxidation effects of fullerenol-containing natural rubberJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010Hiroaki Kondo Abstract Natural rubber (NR) containing fullerenol, C60-OH, was prepared by two methods; one by mixing C60-OH aqueous solution to NR latex followed by coagulation (wet method) and the other by mixing C60-OH powder with solid rubber by an open roll mixer (dry method). C60-OH mixed by wet method was homogeneously dispersed in the rubber, while one mixed by dry method was particles in the size up to 70 ,m. The former exhibited large reinforcing and antiaging effect than the latter. The large antiaging effect was explained by the finding that C60-OH had large radical scavenging ability and gel forming ability during heat treatment. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Protective effect of arjunolic acid against arsenic-induced oxidative stress in mouse brain,JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 1 2008Mahua Sinha Abstract Arsenic, a notoriously poisonous metalloid, is ubiquitous in the environment, and it affects nearly all organ systems of animals including humans. The present study was designed to investigate the preventive role of a triterpenoid saponin, arjunolic acid against arsenic-induced oxidative damage in murine brain. Sodium arsenite was selected as a source of arsenic for this study. The free-radical-scavenging activity and the in vivo antioxidant power of arjunolic acid were determined from its 2,2-diphenyl-1-picryl hydrazyl radical scavenging ability and ferric reducing/antioxidant power assay, respectively. Oral administration of sodium arsenite at a dose of 10 mg/kg body weight for 2 days significantly decreased the activities of antioxidant enzymes, superoxide dismutase, catalase, glutathione- S -transferase, glutathione reductase and glutathione peroxidase, the level of cellular metabolites, reduced glutathione, total thiols and increased the level of oxidized glutathione. In addition, it enhanced the levels of lipid peroxidation end products and protein carbonyl content. Treatment with arjunolic acid at a dose of 20 mg/kg body weight for 4 days prior to arsenic administration almost normalized above indices. Histological findings due to arsenic intoxication and arjunolic acid treatment supported the other biochemical changes in murine brains. Results of 2,2-diphenyl-1-picryl hydrazyl radical scavenging and ferric reducing/antioxidant power assays clearly showed the in vitro radical scavenging as well as the in vivo antioxidant power of arjunolic acid, respectively. The effect of a well-established antioxidant, vitamin C, has been included in the study as a positive control. Combining all, results suggest that arjunolic acid possessed the ability to ameliorate arsenic-induced oxidative insult in murine brain and is probably due to its antioxidant activity. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:15,26, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20209 [source] Antioxidant properties of polar and non-polar extracts of some tropical green leafy vegetablesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2008Ganiyu Oboh Abstract BACKGROUND: The higher consumption of vegetables and fruits could be a practical approach to the management of oxidative stress. The present study sought to compare the antioxidant properties of polar and non-polar constituents of some tropical green leafy vegetables (Struchium sparganophora, Amaranthus cruentus, Telfairia occidentalis, Ocimum gratissimum, Talinium triangulare, Cnidoscolous aconitifolius and Vernonia amygdalina). RESULTS: The polar antioxidant constituents (total phenol (3330,17 572 mg kg,1), total flavonoid (1668,4306 mg kg,1) and vitamin C (224,642 mg kg,1)) were higher than the non-polar antioxidant constituents (total phenol (703,3115 mg kg,1), total flavonoid (130,1303 mg kg,1) and carotenoids (132,1303 mg kg,1)). Furthermore, the polar extracts had a significantly higher (P < 0.05) 1,1-diphenyl-2-picrylhydrazyl radical scavenging ability (except T. triangulare), total antioxidant capacity, reducing power (except T. triangulare and A. cruentus) and Fe(II) chelating ability (except C. aconitifolius and S. sparganophora). However, the polar and non-polar extract of O. gratissimum had the highest antioxidant properties while that of T. triangulare had the least antioxidant properties. CONCLUSION: The polar extract of most of the vegetables had higher antioxidant properties than the non-polar extract, with O. gratissimum extracts having the highest antioxidant properties. Copyright © 2008 Society of Chemical Industry [source] Free Zn2+ enhances inhibitory effects of EGCG on the growth of PC-3 cellsMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 4 2008Shi-li Sun Abstract Epigallocatechin-3-gallate (EGCG), a major component of green tea, has both preventive and therapeutic beneficial actions in prostate cancer. In the present study, we compared the growth inhibitory effects and the antioxidant and ability to modify cell membrane permeation of zinc-EGCG complex and Zn2+/EGCG mixture on androgen-insensitive prostate cancer (PC-3) cells. It was noted that free Zn2+ enhanced the growth inhibitory effects of EGCG on PC-3 cells at 160 ,mol/L concentration, whereas zinc-EGCG complex was ineffective. EGCG showed potent free radical scavenging ability in the presence of Zn2+. EGCG in the presence of Zn2+ was more effective than EGCG alone in enhancing the permeability of the cell membrane, whereas zinc-EGCG complex had no effect on PC-3 cell membrane permeability. These results indicate that though Zn2+ enhanced the action of EGCG on PC-3 cells, zinc-EGCG complex is highly unlikely to be formed in the presence of Zn2+ and EGCG to explain the potentiating action of Zn2+ on the growth inhibitory property of EGCG on PC-3 cells. [source] Protective Effect of Ebselen on Aflatoxin B1 -Induced Cytotoxicity in Primary Rat HepatocytesBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 4 2000Cheng-Feng Yang Recent studies have shown that aflatoxin B1 enhances reactive oxygen species formation and causes oxidative damage, which may ultimately contribute to the cytotoxicity and carcinogenic effect of aflatoxin B1. Ebselen, 2-phenyl-1,2-benzoisoseleazol-3(H)-one, a synthetic seleno-organic compound has been shown to possess glutathione peroxidase-like activity and free radical scavenging ability. Thus present study was designed to investigate the protective effect of ebselen on aflatoxin B1 -induced cytotoxicity in primary rat hepatocytes. Aflatoxin B1 -induced cytotoxicity and lipid peroxidation were determined by lactate dehydrogenase leakage and malondialdehyde generation, respectively. Intracellular reactive oxygen species level was measured using the fluorescent probe 2,,7,-dichlorofluorescin diacetate, and the intracellular reduced glutathione concentration was determined with a fluorometric method. Ebselen was found to display a dose-dependent protective effect on lactate dehydrogenase leakage and malondialdehyde generation caused by aflatoxin B1 exposure. The results also demonstrate that ebselen efficiently inhibits the intracellular reactive oxygen species formation in aflatoxin B1 -treated hepatocytes in a dose and time-dependent manner. It was also noted that ebselen was able to increase the intracellular reduced glutathione concentration, both in the control and in aflatoxin B1 -treated hepatocytes. The protection of ebselen against aflatoxin B1 cytotoxicity, however, was not affected by lowering the concentration of intracellular reduced glutathione. The overall data indicate that ebselen possesses a potent protective effect against aflatoxin B1 -induced cytotoxicity, and the main mechanism involved in the protection may be its strong capability in inhibiting intracellular reactive oxygen species formation and preventing oxidative damage. [source] Date seed oil limit oxidative injuries induced by hydrogen peroxide in human skin organ cultureBIOFACTORS, Issue 2-3 2007Ines Dammak Abstract The skin is chronically exposed to pro-oxidant agents, leading to the generation of reactive oxygen species (ROS). To protect the skin against an over-load of oxidant species, we studied the chemoprotective effect of one new natural product: "date seed oil: DSO". This oil may serve as a potential source of natural antioxidants such as phenols and tocopherols. Here, the antioxidative potential of DSO was compared that of to extra virgin olive oil. Adult human skin was maintained in organ culture in the presence of the DSO and extra virgin olive oil before the addition of hydrogen peroxide (H2O2 ), in order to prevent the tissue from its oxidizing effects. Skin specimens were collected for histology and for melanin studies. In the investigated model system, DSO protects skin against oxidative injuries. It has a significant chemoprotective effect, by inhibition of damage caused by H2O2 compared with specimens without such addition endowing with a radical scavenging ability. The various components from DSO were much more potent antioxidant and more free radical scavengers of the H2O2 than those of olive oil. Our study shows that topical DSO treatment of the skin stimulates events in the epidermis leading to repair skin damage possibly due to antioxidant synergisms. [source] | ||||||||||||||||