Anthocyanins antioxidant effects

The phenolic antioxidant activity in the corn oil emulsions of 17 selected Spanish wines and two Californian wines was examined for their preventive capability for lipid oxidation as dietary antioxidants. The inhibition of hydroperoxide formation [measured as percent of control for 10 iM gallic acid equivalents (GAE)] was increased from 8.4 to 40.2% in the presence of the red wines, from 20.9 to 45.8% with the rose wines, and from 6.5 to 47.0% with the white wines. The inhibition of hydroperoxide formation at 20 xM GAE was increased from 11.9 to 34.1% in the presence of red wines, from 0.1 to 34.5% with the rose wines, and from 3.3 to 37.2% with the white wines. The inhibition of the hexanal formation at 10 (jlM GAE was increased from 23.6 to 64.4% in the presence of red wines, from 42.7 to 68.5% with the rose wines, and from 28.4 to 68.8% with the white wines. Moreover, the inhibition of the hexanal formation at 20 xM GAE was increased from 33.0 to 46.3% in the presence of red wines, from 11.3 to 66.5% with the rose wines, and from - 16.7 to + 21.0% with the white wines. The antioxidant effect declined apparently with increasing concentration. The antioxidant activity might be ascribed to the five main groups of phenolics identified in the wines benzoic acids, anthocyanins, flavan-3-ols, flavonols, and hexanal [38]. 

Studies in humans of antioxidant effects following consumption of anthocyanins are less definitive. Much of the early work on anthocyanins has resulted from studies... 

The research excitement about a< af has derived from its prodigious content of polyphenols—anthocyanins, proanthocyanidins, and tannins. These polyphenols collectively create strong antioxidant effects in test-tube studies. 

Narayan, M.S., Naidu, K.A., Ravishankar, G.A., Srinivas, L. Venkataraman, L.V (1999). Antioxidant effect of anthocyanin on enzymatic and non-enzymatic lipid peroxidation. Prostaglandins, Leukotrienes, and Essential Fatty Acids, 60, 1-4. 

Mertens-Talcott, S., Rios, J., Jilma-Stohlawetz, P., Pacheco-Palencia, L., Meibohm, B., Talcott, S., and Derendorf, H. 2008. Pharmacokinetics of anthocyanins and antioxidant effects after the consumption of anthooyanin-rich acai juice and pulp (Euterpe oleracea Mart) in human healthy volunteers. Journal of Agricultural and Food Chemistry, 56(17), 7796-7802. 

Lohachoompol, V., 8rzednicki, G., and Craske, J. 2004. Change of total anthocyanins in blueberries and their antioxidant effect after drying and freezing. Journal ofBiomedicine and Biotechnology, 5, 248-252. 

The chemopreventive activity of hibiscus extracts has been extensively studied recently. The protective effect was demonstrated against human carcinomas, chemically induced toxicity,and hepatotoxici-jy 11,21-27 Antimutagenic activity has also been demonstrated both in vitro and in vivo The chemopreventive activity is attributed mainly to the antioxidant effect of the anthocyanins present in hibiscus extracts. Roselle decoction or infusion reportedly has hypotensive properties with no side effects. This effect has been investigated in more depth in experimental animals and in humans over the past decade and the results seem to support earlier studies especially in mild to moderate hypertension. Suggested mechanisms of action for the hypotensive activity include inhibition of Ca influx into vascular smooth muscle, NO-cGMP-relaxant pathway, and possible acetylcholine-and histamine-like vasorelaxation. ... 

Anthocyanins and anthocyanidins, compounds present with high structural diversity in fruits and wines, showed a pattern as antioxidants different from that of the tea catechins with respect to the effect of substituents. In a liposomal model system induced peroxidation was inhibited increasingly by anthocyanins/ anthocyanidins with an increasing number of hydroxyl groups in the B-ring (Fig. 16.6), while the opposite was seen for the catechins (Seeram and Nair, 2002). For anthocyanidins, the presence of a 3-hydroxy group is important... 

Fruifs and vegetables also contain ofher bioactive substances such as polyphenols (including well-known pigments anthocyanins, flavonols) and non-provitamin A carotenoids (mainly lycopene, lutein, and zeaxanthin) that may have protective effects on chronic diseases. Polyphenols and carotenoids are known to display antioxidant activities, counteracting oxidative alterations in cells. Besides these antioxidant properties, these colored bioactive substances may exert other actions on cell signaling and gene expression. 

Cyanidin is the most common anthocyanin in foods. In addition, anthocyanins are stabilized by the formation of complexes with other flavonoids (co-pigmentation). In the United States, the daily anthocyanin consumption is estimated at about 200 mg. Several promising studies have reported that consumption of anthocyanin-rich foods is associated with reductions of the risks of cancers - and atherosclerosis and with preventive effects against age-related neuronal and behavioral declines. These beneficial effects of anthocyanins might be related to their reported biological actions such as modulators of immune response and as antioxidants. Knowledge of anthocyanin bioavailability and metabolism is thus essential to better understand their positive health effects. 

Zheng Y, Wang CY, Wang SY and Zheng W. 2003. Effect of high-oxygen atmospheres on blueberry phenolics, anthocyanins, and antioxidant capacity. J Agric Food Chem 51 7162-7169. 

Rababah, TM, Ereifej, KI and Howard, L. 2005. Effect of ascorbic acid and dehydration on concentrations of total phenolics, antioxidant capacity, anthocyanins, and color in fruits. J Agric Food Chem 53(ll) 4444-4447. 

Figure 11.1. Effect of storage temperature (0, 5, 10°C) on (I) total anthocyanins (mg/100 g FW), (II) total phenols (mg/100 g FW), and (III) antioxidant capacity measured as ORAC (p.mol TE/g FW) of strawberry fruit (cv. Chandler). Bars show the final values after treatments. Different letters on top of the bars indicate statistical differences among treatments (p < 0.05).

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