Resveratrol antioxidant activity

In products with complex combinations of various types of flavonoids and other phenolic compounds, effort has been made to ascribe the antioxidant activity of the product to different classes of polyphenols. Frankel et al. (1995) studied 20 selected California wines and related the antioxidant activity to the polyphenolic components of the wines, rather than to resveratrol. Antioxidant activity was measured by the ability of the wines to inhibit copper-catalyzed oxidation of human LDL. The correlation coefficient between antioxidant activity and total phenolic components of the wines was r = 0.94. Individual phenolic compounds (gallic acid, catechin, myricetin, quercetin, caffeic acid, rutin, epicatechin, cyanidin, malvidin-3-glucoside) contributed to the antioxidant activity. The correlation coefficient for the compounds ranged from r = 0.92 to r = 0.38 in descending order. 

There are numerous other polyphenolic compounds possessing in vitro and in vivo antioxidative activity. Several examples of these compounds are cited below. One of nonflavonoid polyphenols of particular interest is resveratrol (3,5,4 -trihydroxy-Znmv-stilbcne, Figure 29.8), which has been identified as a potential cancer chemopreventive agent and an antimutagen [182]. It has been found that resveratrol is the efficient inhibitor of cyclooxygenase and the inhibitor of free radical-mediated cellular processes. For example, resveratrol is a better free radical scavenger than a-tocopherol or ascorbic acid but has nearly the same activity as... 

A comparison with its different derivatives shows that 4 -OH is not a sole reactive group responsible for the antioxidant activity of resveratrol, while the trans-conformation is absolutely necessary for the inhibition of cell proliferation [187], However, similar to flavonoids resveratrol may exhibit prooxidant properties, for example to promote DNA fragmentation, although its prooxidant activity seems to be unimportant under physiological conditions [188],... 

Olas B, Wachowicz B, Saluk-Juszczak J, Zielinski T, Kaca W, Buczynski A. 2001. Antioxidant activity of resveratrol in endotoxin-stimulated blood platelets. Cell Biol... 

Stivala LA, Savio M, Carafoli F, Perucca P, Bianchi L, Maga G, Forti L, Pagnoni UM, Albini A, Prosperi E, Vannini V. 2001. Specific structural determinants are responsible for the antioxidant activity and the cell cycle effects of resveratrol. J Biol Chem 276 22586-22594. 

Hydroxytyrosol has been also referred to as a potent agent with anticarcinogenic activity. Grape pomace is rich in a large number of polyphenolic compounds with high antioxidant activity, with resveratrol being probably the most known and referred to in the scientific literature. 

Trans-resveratrol (trans-3,5,4 -trihydroxystilbene) is a non-flavonoid polyphenol found in grapes, mulberries, and other food prod-ucts. It is responsible for the antioxidant activity of red wine. Intake of moderate amount of red wine has been found to reduce the risk of cardiovascular diseases. In addition to antioxidant activity, resveratrol could inhibit platelet aggregation, and showed anticancer activity. The phenoxyl radicals of resveratrol produced during oxidation by hydroxyl radicals, one-electron oxidants, and peroxyl radicals showed absorption maximum at 410 nm (Fig. I). Reports indicate that trans-resveratrol is a better radical scavenger than vitamins E and C and its activity is similar to that of the flavonoids epicatechin and quercetin. From the comparison of the spectral and kinetic properties of the transients derived from trans-resveratrol and its analogues, it could be concluded that in the neutral and acidic solutions, the para-hydroxy... 

Fig. 3 Dual-HPLC plots of two antioxidants trolox and resveratrol. Upper chromatograms show UV profiles registered at 250 nm and lower chromatograms ABTS scavenging (antioxidant activity) profiles registered at 600 nm (negative peak). In (A), trolox was detected with a retention time of 6.2 min. Inset Calibration curve of scavenging activity (peak areas at 600 nm) for different amounts of trolox. In (B), resveratrol was detected at 5.0 min.

Resveratrol (1) is famous for its antioxidant activities, which could reduce or diminish oxidative stress and provide cardiovascular protection [448-451,494,495]. Recently, the structural basis of antioxidant activity of resveratrol (1) has been evident based on ab initio calculations and experimental crystal structure [496]. 

Many natural stilbene glycosides have also been reported to have significant antioxidant activities, for example, (Z)-astringin and ( )-and (Z)-resveratrol-4 -0-6-D-glucopyranoside [478], astringin [479], 2,3,4, 5-tetrahydroxy stilbene-2-0-6-D-glucopyranoside [20], compounds 51 [28], 53 [11], 61 and 62 [500]. 

Fremont, L., Belguendou, L. and Delpal, S. (1999) Antioxidant activity of resveratrol and alcohol-free wine polyphenols related to LDL oxidation and polyunsaturated fatty acids, Life Sci., 64(26), 2511-2521. 

During the course of screening antioxidants from plants, Baek et al. isolated a neolignan from the bark of M. officinalis [37]. A biphenyl compound, 5, 5 -di-2-propenyl-2-hydroxy-3, 2, 3 -trimethoxy-l-l -biphenyl (15), was found to have antioxidant activity similar to commercial synthetic antioxidants 2, 6-di-ter/-butyl-4-methylphenol (BHT) or 3-tert-butyl-4-hydroxyanisole (BHA). Antioxidants are compounds that inactivate free radicals in the body. Free radicals can cause cancer since it can promote the growth of cells by initiating spontaneous mitosis. Furthermore, phenolic antioxidants in wine, especially resveratrol (16), have demonstrated the ability to inhibit human low density lipid (LDL) oxidation in vitro [38]. Frankel mentions other studies suggesting... 

Resveratrol 3-O-P-D-glucoside (1) Antioxidant activity (scavenging of free radicals, and inhibition of lipid peroxidation) 61... 

The antioxidant activity of resveratrol (Fig. 5), a stilbenoid derivative, has been reported [130]. 

Many dietary factors are believed to exert their potent antidisease effects because they possess strong antioxidant activities. However, direct compelling evidence for this supposition is lacking [22] and is difficult to obtain. A multitude of descriptive studies correlating the presence of resveratrol and protection against oxidative stress have been performed over the past 1-2 years. Almost all of these reports present indirect, correlative evidence. The data clearly support an antioxidant function for resveratrol but do very little to provide mechanistic evidence for its action in vivo. However, a few of the most recent studies are highlighted. 

In support of the antioxidant activity of resveratrol, a number of studies have demonstrated protective effects on oxidative cardiovascular injury." - In animal models, preinfusion of resveratrol prevents reperfusion-induced arrhythmias and mortality due to its antioxidant, free radical-scavenging activity as well as its ability to increase NO release. " These in vivo findings are supported by in vitro observations indicating that resveratrol significantly inhibits the ischemia/reperfusion-induced leukocyte recruitment and superoxide-related microvascular barrier dys-... 

Documented effects The alkaloid spherophysine, which was isolated from the aboveground plant parts, has hypotensive activity and effects uterine action. In the form of a benzoic-acid salt, it is used for essential hypertension of the first and second degrees. Spherophysine is used for arterial hypertension, weak birthing activity (labor difficulties), and post natal bleeding (Sokolov and Zamotaev 1989). A stilbene isolated from the plant was synthesized and tested for antioxidant activity and showed superior antioxidative activity when compared to the well-known antioxidants resveratrol, vitamin C and butylated hydroxyanisole (BHA) (Venkateswarlu et al. 2003). Additionally, synthesized stilbenes based on naturally occurring compounds were active against leukemia and lymphoma cell lines (Tolomeo et al. 2005). 

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