Antioxidant properties procyanidins

While the positive health benefits associated with the consumption of a flavonoid-rich diet cannot be attributed to any one factor, the antioxidant properties of certain flavonoids have been the focus of considerable attention [8]. The antioxidant actions of chocolate flavonoids were first studied inhibiting LDL-oxidation [9,10]. As a consequence of the availability of purified procyanidins from cocoa (dimer-decamer), this particular family of... 

Bos MA, Vennat B, Meunier MT, Pouget MP, Pourrat A, Fialip J (1996) Procyanidins from tormentil antioxidant properties towards lipoperoxidation and anti-elastase activity. Biol Pharmacol Bull 19 146-148... 

The chemical stmctures of flavonols and procyanidins might be important for antioxidant activity because of free radical trapping and chelation of redox-active metals properties. Adamson et al. [32] indicated that polyphenol content positively correlated with antioxidant properties as measured by ORAC. AU polyphenols possess antioxidant properties in vitro but this activity is not well characterized in human. 

Phenolic substances in red wine were shown to inhibit LDL oxidation in vitro [95]. In previous studies, red wine-derived phenolic acids [115,116], resveratrol [117], flavonols (quercetin, myricetin) [68,118,119], catechins [66,120], and the grape extract itself [121,122] have been shown to possess antioxidant properties. The finding that ethanol and wine stripped of phenols did not affect LDL oxidation further confirmed that the active antioxidant components in red wine are phenolic compounds [123]. Red wine fractionation revealed major antioxidative potency to monomeric catechins, procyanidins, monomeric anthocyanidins, and phenolic acids [123]. The flavonol quercetin and the flavonol catechin were both tested for antioxidative and antiatherogenic effects in the atherosclerotic E° mice [111]. E° mice at the age of 4 weeks were supplemented for up to 6 weeks in their drinking water with placebo (1.1% alcohol) or with catechin or quercetin (50 pg/day/mouse). The atherosclerotic lesion area was smaller by 39% or by 46%, respectively, in the treated mice than in E° mice that were treated with placebo (Fig. 4A-E). 

Similar to hydrophilic flavonoids, hydrophobic flavonoids can affect membrane permeability. Alterations in this biophysical property of liposome bilayers lead to the release of bulky molecules entrapped into the inner aqueous space. As mentioned in the previous section, a strong correlation was found between flavonoid retention to a hydrophobic matrix and their capacity to induce membrane leakage [Ollila et al., 2002]. Interestingly, hydrophilic flavonoids, such as (—)-epicatechin and related procyanidins (dimer to hex-amer) prevented Fe2 + -mediated liposome permeabilization, although in this case the beneficial effect could be related to both their antioxidant and metal chelating capacities and their membrane stabilizing properties [Verstraeten et al., 2004],... 

Packer, L., Rimbach, G., and Virgili, F. Antioxidant activity and biologic properties of a procyanidin-rich extract from pine (Pinus martima) bark, pycnogenol, Free Radic. Biol. Med., 27, 704—724, 1999. 

Torres, J. B., Varela, M. T., Garcia, J., Carilla, C., Matito, J. J., Centelles, M., Cascante, X., Sort, R., and Bobet, A. (2002). Valorization of grape (Vitis vinifera) by products. Antioxidant and biological properties of polyphenolic fractions differing in procyanidin composition and flavonol content.. Agri. Food. Chem. 50, 7548-7555. 

Over the last two decades, the scientific community has become aware of the potential health-related benefits of antioxidants and the properties of polyphenols-rich dark chocolate and cocoa. More than 200 studies were reported on bioactive compounds, chemical compositions, and health benefits of cocoa and cocoa products. Many of the proposed health-protective activities associated with the crmsumption of cocoa and chocolate have been attributed to flavan-3-ols, including monomers. Reported pharmacological activities of procyanidins include antioxidative and anticancer effects, protection against cardiovascular disease, risk reduction of blood clotting, protection against urinary tract infectirms, decrease of LDL-c, decrease of blood pressure, and improvement of endothelium vasodilatation. Moreover, there is some scientific evidence about an increase in blood flow and perfusion of the brain by... 

In fact, many aspects beyond the functional properties must be considered for the addition of polyphenols to dairy products. Apart from their antioxidant capacity, their sensorial attributes such as bitterness or the astringency of procyanidins can be easily translated into the dairy product [160]. When grape seed extract was added to low-fat ultra-high temperature (UHT) milk, the flavor characteristics of the milk were suppressed. Moreover, astringency and bitterness were also detected in fortified milks. The authors suggest joining this extract to cyclodextrins, thus forming complex polyphenols that result in reduced perception of sensory attributes [160, 161]. 

Medina I, Lois S, Lizarraga D, Pazos M, Tourino S, Cascante M, Torres JL (2006) Functional fatty fish supplemented with grape procyanidins. Antioxidant and proapoptotic properties on colon cell lines. J Agric Food Chem 54 3598-3603... 

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