Free-radical scavenging activity

Pippenger, C.E., Meng, X., Stolfi, V, McGonagle, B. and Fazio, V.W. (1991). Free radical scavenging activities and trace element concentrations in erythrocytes and plasma of adult patients with inflammatory bowel disease. In Inflammatory Bowel Diseases. Progress in Basic Research and Clinical Implications (eds. H. Gocbell, K. Ewe, H. Malchow and Ch. Koelbel) p. 33. Kluwer Academic Publishers, Lancaster. 

Bain, S.C., Le Guen, C.A., Lunec, J. and Barnett, A.H. (1991). Comparison of the free radical scavenging activity of captopril versus enalapril a three-month trial in vivo study in hypertensive diabetic patients. J. Human Hypertens. 5, 511-515. 

A major contribution of the free-radical scavenging activity in blood plasma is attributable to the macro-molecular proteins (Wayner et al., 1985) of which albumin is a primary component and trapping agertt (Holt et al., 1984). Serum sulphydryl levels, primarily albumin-related, are decreased in subjects with rheumatoid complicated coalworkers pneumoconiosis, indicative of exacerbated inflammatory R.OM production (Thomas and Evans, 1975). Experimental asbestos inhalation in rats leads to an adaptive but evidendy insufficient response by an increase in endogenous antioxidant enzymes (Janssen etal., 1990). Protection of the vascular endothelium against iron-mediated ROM generation and injury is afforded by the iron sequestiant protein ferritin (Balia et al., 1992). 

The purported prophylactic use of Japanese herbal medicines to combat neuronal ageing has been related to their free-radical scavenging activity (Hiramatsu a al., 1992). Inhibition of the pro-inflammatory effects of cytokine interleukin-1 by recombinant endogenous interleukin-1 receptor antagonist in experimental rats is associated with alleviation of excitotoxic neuronal damage, an action which has also been related to the antiinflammatory effect of lipocortin 1 (Relton and Roth well, 1992). 

Jinno, J., Mori, H., Oshiro, Y., Kikuchi, T. and Sakurai, H. (1991). Evaluation of free radical scavenging activity of OPC-14117 by electron spin resonance technique. Free Rad. Res. Commun. 15, 223-230. 

An extract from Lactuca indica showed significant free radical scavenging activity, and protected phixl74 supercoiled DNA against strand cleavage and reduced oxidative stress in human promyelocytic leukemia HL-60 cells. On account of protocatechulic acid, methyl p-hydroxybenzoate, caffeic acid, 3,5-dicaffeoylquinic acid, luteolin 7-O-fT glucopyranoside, and quercetin 3-0-(3-g 1 ucopyranoside are the major antioxidative constituents (111). 

Bajpai M, Mishra A and Prakash D. 2005. Antioxidant and free radical scavenging activities of some leafy vegetables. Int J Food Sci Nutr 56(7) 473-481. 

Calliste CA, Trouillas P, Allais DP, Simon A and Duroux JL. 2001. Free radical scavenging activities measured by electron spin resonance spectroscopy and B16 cell antiproliferative behaviors of seven plants. J Agric Food Chem 49(7) 3321-3327. 

Kefalas P, Kallithraka S, Parejo I and Makris DP. 2003. A comparative study on the in vitro antiradical activity and hydroxyl free radical scavenging activity in aged red wines. Food Sci Technol Int 9(6) 383-385. 

Orhan I, Aydin A, Colkesen A, Sener B and Isimer AI. 2003. Free radical scavenging activities of some edible fruit seeds. Pharm Biol 41(3) 163—165. 

Sanchez-Moreno C. 2002. Review Methods used to evaluate the free radical scavenging activity in foods and biological systems. Food Sci Technol Int 8(3) 121—137. 

Schmeda-Hirschmann G, Feresin G, Tapia A, Hilgert N and Theoduloz C. 2005. Proximate composition and free radical scavenging activity of edible fruits from the Argentinian Yungas. J Sci Food Agric... 

Singh N and Rajini PS. 2003. Free radical scavenging activity of an aqueous extract of potato peel. Food Chem 85 611-616. 

Wang CY, Wang SY, Yin JJ, Parry J and Yu LL. 2007. Enhancing antioxidant, antiproliferation, and free radical scavenging activities in strawberries with essential oils. J Agric Food Chem 55(16) 6527-6532. 

Huge literature on biological functions of flavonoids and their antioxidant and free radical scavenging activities successfully competes with work on antioxidant effects of vitamins E and C. Flavonoids have been reported to exert multiple biological effects and exhibit antiinflammatory, antiallergic, antiviral, and anticancer activities [85 89], However, considering flavonoids as the inhibitors of free radical-mediated processes, two types of their reactions should be discussed flavonoids as free radical scavengers (antioxidants) and flavonoids as metal chelators. 

From chemical point of view, efficient free radical scavengers must contain substituents with the very weak C—H, O—H, or S—H bonds, from which reactive free radicals are able to abstract a hydrogen atom. It can be seen that the antioxidants discussed above (ascorbic acid, a-tocopherol, ubihydroquinones, glutathione, etc) fall under this category. However, many other compounds manifest free radical scavenging activity in in vitro and in vivo systems. 

NADPH might be considered as an indirect antioxidant due to its function as the reductant of various oxidized substrates, for example in the re-reduction of GSSG into GSH. However, it has recently been shown [1] that NADPH possesses the free radical scavenging activity reacting with such free radicals as CO/, N02 ROO and R0 . It should be noted that the efficiency of NADPH may increase under in vivo conditions due to its regeneration by numerous enzymes. 

It has been established that the free radical scavenger activity of flavonoids is responsible for the antioxidant effect [95,96], The beneficial antitumour effect of quercetin has also been demonstrated [97,98],... 

Chiang LY, Lu F-J, Lin J-T (1995) Free radical scavenging activity of water-soluble fullerenols. Chem. Commun. 1 1283-1284. 

Jeng US, Lin TL, Chang TS, Lee HY, Hsu CH, Hsieh YW, Canteenwala T, Chiang LY (2001) Comparison of the aggregation behavior of water-soluble hexa(sulfobutyl)fullerenes and polyhydroxylated fullerenes for their free-radical scavenging activity. Prog. Colloid Polym. Sci. 118 232-237. 

Lai HS, Chen WJ, Chiang LY (2000a) Free radical scavenging activity of fullerenol on the ischemia-reperfusion intestine in dogs. World J. Surg. 24 450 154. 

Free radical scavenging activity was assessed using the DPPH (1, 1-di-phenyl-2-picrylhydrazyl) assay as described by Harbilas et al. [22] with incubation time increased to 65 min. Briefly, 250 tiL of 100 timol/L DPPH dissolved in methanol was added to 40 p.L of extract (tested at 5 concentrations) in a microplate well. A standard curve of ascorbic acid (positive control) was included as a reference and all data were blanked against a treatment with only methanol. Absorbance was read with a microplate reader at 517 nm. The inhibitory concentration for 50% scavenging (IC50) of each extract was calculated and compared to the IC50 of the ascorbic acid standard curve. 

Nakagawa, K., Ueno, A., and Nishikawa, Y. (2006). Interactions between carnosine and captopril on free radical scavenging activity and angiotensin-converting enzyme activity in vitro. Yakugaku Zasshi 125, 37-42. 

Alviano, D.S., K. F. Rodrigues, S. G. Leitao, et al. Antinociceptive and free radical scavenging activities of Cocos nucifera L. (Palmae) husk fiber aqueous extract. J Ethnopharmacol 2004 92(2-3) 269-273. 

HV177 Yu Y. M., W. C. Chang, C. T. Chang, C. L. Hsieh, and C. E. Tsai. Effects of young barley leaf extract and antioxidative vitamins on LDL oxidation and free radical scavenging activities in type 2 diabetes. Diabetes Metab... 

Sun, D. et al., Flavonols from Myrica esculenta bark, Linchen Huaxue Yu Gongye, 11, 251, 1991. Akdemir, Z.S. et al., Polyphenolic compounds from Geranium pratense and their free radical scavenging activities. Phytochemistry, 56, 189, 2001. 

Xanthosoma violaceum, Araceae, widely distributed in Dominican Republic, Puerto Rico, Guatemala, and Equator, was investigated for in vitro antioxidant and free-radical scavenger activities. The fraction rich in C-glycosylflavones showed with l,l-diphenyl-2-picryl-hydrazyl radical (DPPH) test an EC50 of 11.6 pg/ml, compared with quercetin (2.3 pg/ml) and a-tocopherol (10.1 pg/ml). 

W00276990>. Thus, compounds 423 and 424 have been claimed to exhibit significant analgesic activity superior to that of aspirin, free radical-scavenging activity, as well as carcinogenic potential <1999IJB1075>. 

Mandal P, Misra TK, Ghosal M. Free-radical scavenging activity and phytochemical analysis in the leaf and stem of Drymaria diandra Blume. International Journal of Integrative Biology. 2009 7(2) 80-84. 

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