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Blueberry as Antioxidant A 2005 study which was published in the Journal of Agricultural food Chemicals compared the antioxidant properties of prepared blueberry with two anthocyanin-derived extracts. The extracts¹ abilities to inhibit lipid peroxidation, induced by 2,2¹-azobis(2-methyl-propanimidamide) dihydrochloride in a liposomal membrane system were examined. The antioxidant capacities of the extracts were evaluated through monitoring oxygen consumption and by measuring the formation of conjugated dienes. All of the extracts provided protection of membranes against peroxyl radicals by increasing the induction time of oxidation ( J.Agric Food Chem. 2005 Aug 24;53(17):6896-902). A 2005 study conducted by Han, Li, Mazza and Yang in Beijing, China examined the effect of anthocyanin rich fruit extract (blueberry, blacjcurrant, chokeberry) on PGE2 produced by Endothelia Cells. When stimulated by LPS, the production of PGE2 by endothelial cells were increased two fold. Blueberry extract inhibit such action. 100 microg/ml of Blueberry extract keeps the production of PGE2 in normal level. 700 microg/mL of Blackcurrant extract and 500 microg/ml Chokeberry extract also inhibit the releasing of PGE2 (Biochem Cell Biol. 2005 Oct;83(5):637-43). A 2003 study, published in the Journal of Agriculture and Food Chemistry, compared the antioxidant ability of blueberries with that of red wine. Researchers found that a moderate drink (about 4 ounces) of white wine contained .47 mmol of free radical absorbing antioxidants, red wine provided 2.04 mmol, and a wine made from high-bush blueberries delivered 2.42 mmol of these protective plant compounds (Sanchez-Moreno C, Cao G, Ou B, Prior RL. Anthocyanin and proanthocyanidin content in selected white and red wines. Oxygen radical absorbance capacity comparison with nontraditional wines obtained from high-bush blueberry. J Agric Food Chem. Aug 13;51(17):4889-96).
Clinical Abstracts Antioxidant properties of prepared blueberry (Vaccinium myrtillus) extracts. J Agric Food Chem. 2005 Aug 24;53(17):6896-902 Faria A, Oliveira J, Neves P, Gameiro P, Santos-Buelga C, de Freitas V, Mateus N. Centro de Investigacao em Quimica, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal. A blueberry extract (A) and two anthocyanin-derived extracts (B and C) were prepared. The contents of polyphenols, flavonoids, anthocyanins, and anthocyanin-derived pigments of the extracts were determined for the first time. The pigment profile of blueberry extract A corresponded to 15 anthocyanins, whereas extract B was mainly composed of anthocyanin-pyruvic acid adducts of the blueberry original anthocyanins and extract C was mainly composed of the respective vinylpyranoanthocyanin-catechins (portisins). The extracts' abilities to inhibit lipid peroxidation, induced by 2,2'-azobis(2-methyl-propanimidamide) dihydrochloride in a liposomal membrane system were examined. The antioxidant capacities of the extracts were evaluated through monitoring oxygen consumption and by measuring the formation of conjugated dienes. All of the extracts provided protection of membranes against peroxyl radicals by increasing the induction time of oxidation. This effect increased with the polyphenol content and with the structural complexity of the anthocyanin-derived pigments of the extracts. The pigments present in extract C seemed to induce a higher protection of the liposome membranes toward oxidation. In addition, the antiradical properties and the reducing power of the extracts were determined by using DPPH and FRAP methods, respectively. The results from these assays were in agreement with those obtained with the liposome membranes. PMID: 16104817 [PubMed - indexed for MEDLINE] |
