Albumin antioxidant activity

Tsuge, N., Eikawa, Y., Nomura, Y., Yamamoto, M., and Sugisawa, K. (1991). Antioxidative activity of peptides prepared by enzymatic hydrolysis of egg-white albumin. Nippon Nogeikagaku Kaishi 65,1635-1641. 

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). 

Antioxidant activity may also be a nonlinear function of concentration of some antioxidants, that is, TAC values may decrease with increasing concentration of the compound studied (M21, W7). In some methods TAC was reported to be not proportional to the dilution (or volume introduced) of blood plasma (C9, S8, W6). This effect may be due to binding of ABTS + (and other indicators) to plasma proteins, especially albumin (M17), or binding of some sample components to indicator proteins (04) Therefore, analysis of the same volume of the fluids studied can be recommended nevertheless, comparison of results obtained under different conditions can hardly be done in some cases. 

Albumin is an important component of plasma antioxidant activity. 

Table 10.13. Effect of bovine semm albumin (BSA) on inhibition (%) of lipid and protein oxidation on the antioxidant activity of phenolic compounds (5 /uM) in lecithin...

Proteins have strong binding properties with flavonoid antioxidants in foods and biological systems, and generally increase the oxidative stability of liposomes. The addition of bovine serum albumin (BSA) increased the oxidative stability of a lecithin-liposome and changed the relative antioxidant activity of various pairs of flavonoids and phenolic acids (Table 10.13). In the absence of BSA, the activity of phenolic antioxidants decreased in the order ferulic acid > epicatechin > catechin > malvidin > caffeic acid quercetin > propyl gallate. In the presence of BSA, the activity of malvidin increased, followed by rutin and ferulic acid, but the activity of epicatechin and catechin decreased. 

Table I compares glucose with ascorbic acid for a number of oxidative parameters. The higher rate of oxidation, oxidant production, and concomitant protein fragmentation and generation of fluorescence products on albumin by ascorbic acid is also accompanied by aldehyde products able to bind to proteins (Kurata et al, 1973 Kurata and Fujimaki, 1976). The attachment of carbohydrate to albumin (Hunt and Wolff, 1991b) may explain ascorbic acid s ability to inhibit the oxidation of LDL by copper in vitro (Retsky et al., 1993 Jialal et al, 1990). A number of studies have shown that ascorbic acid can decrease the oxidation of LDL by copper, the process usually occurring over several hours. Such observations are not indicative of an antioxidant activity.

Ahnajano, M.P. et al. (2007) Albumin causes a synergistic increase in the antioxidant activity of green tea catechins in oil-in-water emulsions. Food. Chem. 102, 1375-1382... 

Albumin, the most abundant circulating protein in the plasma, exerts important antioxidant activities due to its free radical binding capacity. 

MODIFICATION OF HUMAN SERUM ALBUMIN WITH REACTIVE ALDEHYDES ALTERS THE ANTIOXIDANT ACTIVITY... 

Gugbilmez, C. M., Yemenicioglu, A. Arslanoglu, A. (2007). Antimicrobial and antioxidant activity of edible zein films incorporated with Ijwzyme, albumin proteins and disodlum EDTA. Food Research International, 40,80-91. 

Caeruloplasmin (Cp) is an acute phase glycoprotein with a copper transport function. At least 90% of total plasma copper is bound to Cp with the remaining 10% associated with albumin, histidine and small peptides. Lipid peroxidation requires the presence of trace amounts of transition metals and the copper-containing active site of Cp endows it with antioxidant capacity... 

Gutteridge, J.M.C. (1986). Antioxidant properties of the proteins caeruloplasmin, albumin and transferrin. A study of their activity in serum and synovial fluid fiom patients with rheumatoid arthritis. Biochim. Biophys. Acta 869, 119-127. 

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). 

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