Lignans antioxidative activity

Baderschneider, B. and Winterhalter, P., Isolation and characterization of novel benzoates, cinna-mates, flavonoids, and lignans from riesling wine and screening for antioxidant activity. J. Agric. Food Chem. 49, 2788, 2001. 

The presence of the oxidized metabolites is unique and may provide additional reasons for the health benefits of lignans. Classical antioxidant mechanisms show that the addition of an ortho hydroxyl group to a monophenol enhances the antioxidant activity of the original monophenol. Thus, some of the mammalian lignan metabolites may actually have greater or different activity than the parent lignan. Kitts et al (1999) reported that enterolactone and enterodiol had greater antioxidant activity than the parent... 

Flaxseed was among the best food sources in the prevention of in vivo spontaneous chromosomal damage in mice (Trentin et al., 2004). The exact reason for the chromosomal damage prevention was not identified however, the mechanism may be related to the antioxidant function of flaxseed components. Lignans have antioxidant activity and thus may contribute to the anticancer activity of flaxseed (Kangas et al., 2002 Kitts et al., 1999 Prasad 1997a, Yuan et al., 1999). 

Kitts, D.D., Yuan, Y.V., Wijewickreme, A.N., and Thompson, L.U. 1999. Antioxidant activity of the flaxseed lignan secoisolariciresinol diglycoside and its mammalian lignan metabolites enterodiol... 

Fukuda, Y., Nagata, M., Osawa, T. and Namiki, M. (1986a) Contribution of lignan analogs to antioxidative activity of refined unroasted sesame seed oil. J. Amer. Oil Chem. Soc., 63(8), 1027—1033. 

Lignans of flaxseed exist as secoisolariciresinol diglucoside (SDG 126). SDG is a potent antioxidant in biological systems because of its tendency to associate in the aqueous phase. Much of the work on antioxidant activity of SDG is related to its radical mediated disease prevention (127, 128). Lignans of both sesame (121, 122) and flax (129, 130) have shown hydrogen-donating abihty and scavenging activity for various free radicals. 

Overall, the research effort to identify health properties of the dried plum relies on two primary signatures for superfruit status—dietary fiber and mixed polyphenols. A Japanese research group has done much of the work on polyphenols, establishing a list of candidates for antioxidant or other cellular effects of prune compounds. Oligomeric proanthocyani-dins, chlorogenic acid, caffeoylquinic acid, various other phenolic acids, and lignans have exhibited antioxidant activity in test-tube studies. Each of these compounds is under research for potential beneficial roles supporting human health. 

The antioxidant activity of a series of lignans was studied by Faure et al. [232] in a rat brain homogenate autoxidation test, and lipid peroxidation was evaluated from the luminescence intensity and thiobarbituric reactive product accumulation. Isopregomisin (0.7 pM) was the most active lignan, followed by guayacasin (1.1 pM) and dihydroguaiaretic acid (2.8 pM). The difference in the effect can be explained by the degree of methylation, which increases the activity. 

Oxidative cellular damage by reactive oxygen species such as superoxide anion, hydroperoxy and hyassociated with various human chronic diseases, e.g. cancers, inflammation, arthritis, atherosclerosis and also with the process of ageing. Claims that diet and increased intake of nutrients exhibiting antioxidative activity have a preventative effect on chronic diseases have increased in recent years. In this context, polyphenolic compounds such as tannins, flavonoids, coumarins, lignans and caffeic acid derivatives, which are abundantly contained in a large number of medicinal plants, foods and beverages, are of particular interest for human health care because of the antioxidative properties widely found in plant phenolics. The antioxidative activity of tannins has been extensively studied in various in vitro and in vivo experimental systems and summarized in reviews [96, 97]. Such activity includes the inhibition of lipid peroxidation induced by NADPH-ADP and ascorbic acid-ADP in rat liver microsomes and mitochondria, respectively... 

The antioxidant activity of lignans has also been established. Thus, dihydroguayaretic acid, guayacasin and isopregomisin showed to be powerful antioxidants with similar activities to that of propylgallate [131]. 

Plant foods contain a number of bioactive substances, including phenoUcs. Phenolics such as flavonoids, phenolic acids, lignans and tannins have antioxidant properties, whilst the fermentation process has been d onstrated to modify the amount of these contents. l,l-Diphenyl-2-picryldrazyl (DPPH) and 2,2 -azinobis-(3-ethylbenzothi-azoline-6-sutfonic acid) (ABTS) are tests commonly used to detennine the free radical-scavenging effectiveness of componnds in evaluating the antioxidant activity of food systems. 

Toure A, Xueming X. Flaxseed lignans source, biosynthesis, metabolism, antioxidant activity, bio-active components, and health benefits. Compr Rev Food Sci Food Saf. 2010 9 261-269. 

Toure, A. and Xueming, X. Flaxseed Lignans Source, Biosynthesis, Metabolism, Antioxidant Activity, Bio-Active Components, and Health Benefits. Comprehensive Reviews in Food Science and Food Safety 9, (3), 261-269. 

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