Plasma antioxidants

LEENEN R, ROODENBERG A J c, TiJBURG L B M and WISEMAN s A (2000) A single dose of tea with or without milk increases plasma antioxidant activity in humans , Eur J Clin Nutr, 54 (1), 87-92. 

Langley-Evans SC. 2000. Consumption of black tea elicits an increase in plasma antioxidant potential in humans. Int J Food Sci Nutr 51(5) 309-315. 

Lotito SB and Frei B. 2006. Consumption of flavonoid-rich foods and increased plasma antioxidant capacity in humans cause, consequence, or epiphenomenon Free Radic Biol Med 41(12) 1727—1746. 

Serafini M, Bugianesi R, Maiani G, Valtuena S, De Santis S and Crozier A. 2003. Plasma antioxidants from chocolate. Nature 424(6952)4013. 

These assays measure the level of protection provided to the naturally occurring carotenoid derivative crocin from bleaching by the radical generator AAPH. The assay was originally suggested by Bors and others (1984) and modified by Tubaro and others (1998), who used it to show that plasma antioxidant capacity is deeply influenced by the consumption of wine. The addition of a sample containing chain-breaking antioxidants results in the decrease in the rate of crocin decay. The sample is monitored for 10 min at 443 nm. 

Cao G, Booth, SL, Sadowski JA and Prior RL. 1998. Increases in human plasma antioxidant capacity after consumption of controlled diets high in fruit and vegetables. Am J Clin Nutr 68(5) 1081—1087. 

Ghiselli A, Serafini M, Maiani G, Azzini E and Ferro-Luzzi A. 1995. A fluorescence-based method for measuring total plasma antioxidant capability. Free Radic Biol Med 18(1) 29—36. 

Tubaro F, Ghiselli A, Rapuzzi P, Maiorino M and Ursini F. 1998. Analysis of plasma antioxidant capacity by competition kinetics. Free Radic Biol Med 24(7-8) 1228-1234. 

Modified procedure (ACP kit) Total plasma protein is isolated from low-molecular-weight plasma antioxidants in a single-step liquid gel chromatography procedure and its antiradical capacity ACP is measured in the ACW assay. 

Plasma Concentrations ( utAt) of Endogenous (Nondietary) Phenols and Other Plasma Antioxidants... 

Many investigators have attempted to demonstrate increases in plasma antioxidant capability following the consumption of foods, beverages, or supplements rich in PPT. Table 6.5 summarizes the outcomes of 37 such The test substances in-... 

Thirteen studies (three high and three very high doses) showed no change in plasma antioxidant status ex vivo... 

Ghiselli, A., Natella, F., Guidi, A., Montanari, L., Fantozzi, P., and Scaccini, C., Beer increases plasma antioxidant capacity in humans, J. Nutr. Biochem., 11, 76, 2000. 

Kimura, M., Umegaki, K., Kasuya, Y., Sugisawa, A., and Higuchi, M., The relation between single/double or repeated tea catechin ingestions and plasma antioxidant activity in humans, Eur. J. Clin. Nutr., 56, 1186, 2002. 

Pedersen, C.B., Kyle, J., Jenkinson, A.M., Gardner, P.T., McPhail, D.B., and Duthie, G.G., Effects of blueberry and cranberry juice consumption on the plasma antioxidant capacity of healthy female volunteers, Eur. J. Clin. Nutr., 54, 405, 2000. 

In addition to enzymatic oxidation, flavonoid oxidation can take place via autoxidation (metal-catalyzed oxidation by dioxygen) and ROS scavenging. The former process can be related to flavonoid cytotoxicity (ROS production) while the latter is one of the main antioxidant mechanisms. Both processes may be modulated by flavonoid-protein binding. Although poorly documented so far, these points could be important and, for instance, albumin-flavonoid complexes with an affinity for LDL could act as the true plasma antioxidants participating in the regeneration of a-tocopherol from the a-tocopheryl radical formed... 

In vivo studies were also conducted by several researchers. Anraku et al. (2009) examined the antioxidant effects of water-soluble chitosan in normal subjects by measuring the reduction of indices of oxidative stress. Treatment with chitosan for 4weeks produced a significant decrease in levels of plasma glucose and the atherogenic index, and led to an increase in high-density lipoprotein cholesterol (HDL-C). Chitosan treatment also lowered the ratio of oxidized to reduced albumin and increased total plasma antioxidant activity. Further, Anraku et al. (2011) proved the antioxidant effects of high MW chitosan in normal volunteers, and the obtained results were consistent with previous results observed by Anraku et al. (2009). 

Tea is another important dietary source for flavonoids, In fact, about half of the flavonoid intake in western populations is derived from black tea. Tea was the major source of flavonoids in the Dutch [6,13] and Welsh studies [17]. Only a small number of studies investigated the association between tea consumption and cardiovascular disease risk. No association between tea consumption and cardiovascular disease risk were reported in Scottish men and women [28] and in U.S. men in the Health Professionals follow-up study [29]. However, in a Norwegian population an inverse association was reported between tea intake, serum cholesterol, and mortality from coronary heart disease [30]. Several studies reported that tea consumption did not affect plasma antioxidant activity [31] and hemostatic factors [32]. However, a recent prospective study (the Rotterdam study) of 3,454 men and women 55 years and older followed for 2 to 3 years, showed a significant, inverse association of tea intake with severe (> 5 cm the length of the calcified area) aortic atherosclerosis. Odds ratios decreased approximately 70 % for drinking more than 500 mL/day (4 cups per day). The associations were stronger in women than in men. However, the risk reductions for moderate and mild atherosclerosis were only weak or absent [33]. 

Terao J. 1999. Dietary flavonoids as plasma antioxidants on lipid peroxidation Significance of metabolic conversion In Packer L, Hiramatsu M, Yoshikawa T, Eds. Antioxidant Food Supplements in Fluman Health. San Diego Academic Press, pp. 255-269. 

Honey conveys both phenolic antioxidants and increases plasma antioxidant capacity (Nagai et al., 2001 Schramm et al., 2003). Honey contains flavanoids such as rhamnetin, kaempferol, naringenin, quercetin, and apigenin (see Chapter 31). 

Maggio, D., Barabani, M., Pierandrei, M., Polidori, M.C., Catani, M., Mecocci, P., Senin, U., Pacifici, R., and Cherubini, A. 2003. Marked decrease in plasma antioxidants in aged osteoporotic women Results of a cross-sectional study. J. Clin. Endocrinol. Metabol. 88, 1523-1527. 

Sinclair, A.J., Bayer, A.J., Johnston, J., Warner, C., and Maxwell, S.R. 1998. Altered plasma antioxidant status in subjects with Alzheimer s disease and vascular dementia. Int. J. Geriatr. Psychiatry 13, 840-845. 

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