(PA26) Mechanism of Antioxidant Activity of Natural Food Supplements

Title Mechanism of Antioxidant Activity of Natural Food Supplements
Year 1997
Author I. B. Afanas’ev; J.A. Osato; L.G. Korkina
Publisher International Symposium on Antioxidant Food Supplements in Human Health

MECHANISMS OF ANTIOXIDANT ACTIVITY OF NATURAL FOODSUPPLEMENTS

I.B.Afanas’ev1, J .A.Osato2 and L.G.Korkina3,

 1Vitamin Research Institute, Moscow 117820, Russia,
2Osato Research Institute, Gifu 500, Japan,
3 Russian State Medical University, Moscow 117513, Russia

A lot of up-to-date natural food supplements is claimed to possess antioxidant activity, although its mechanism is not always clear. We have studied the effects of natural food supplement Bio-normalizer (prepared by the fermentation of Carica papaya), bioflavonoid rutin, lipoic acid, α -tocopherol, and ascorbic acid. It was found that the direct antioxidant activity of these substances depends on (1) scavenging of active free radicals, (2) the chelation of transition metal ions capable of catalyzing the decomposition of hydrogen peroxide to hydroxyl radicals (the Fenton reaction), and (3) the balance of their antioxidant and prooxidant properties. Under all the conditions studied, Bio-normalizer and rutin exhibited no prooxidant properties but scavenged superoxide ion and hydroxyl radicals and formed inactive complexes with iron, copper, and lead in both in vitro and in vivo experiments. α – Tocopherol was an effective scavenger of active free radicals but did not react with superoxide ion and exhibited no chelating properties. Lipoic and ascorbic acids manifested both antioxidant and prooxidant activities in model systems depending on their concentrations and other experimental conditions but were principally inhibitory in animal experiments. It has been concluded that the potency of the above natural substances as food supplements depends on their direct and indirect antioxidant properties.


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International Symposium on Antioxidant Food Supplements in Human Health

PROGRAM & ABSTRACTS 

October 16 (Thursday) 18:00 ~ and 18 (Saturday) ~ 12:30, 1997

Hotel Nippon no Yado-KOYO,

Kaminoyama-city, Yamagata Prefecture, Japan