Interaction of dicaffeoylquinic derivatives with peroxynitrite and other reactive nitrogen species.
Arch Biochem Biophys
; 475(1): 66-71, 2008 Jul 01.
Article
em En
| MEDLINE
| ID: mdl-18455492
ABSTRACT
Plant phenolic antioxidants, among them catechins and hydroxycinnamoyl conjugates, constitute a well defined class of inhibitors of reactive nitrogen species (RNS). To gain deeper insight in this field, we examined the effects of 3,5-di-O-caffeoylquinic acid (DCA), its methyl ester (DCE) and epigallocatechin gallate (EGCG) in nitrative and oxidative processes. These compounds were found to be strong inhibitors of the nitration of tyrosine residues induced by ONOO- in bovine seroalbumin, with their IC50 values (10-40 microM) notably decreasing in the presence of bicarbonate. When studied on the intracellular protein tyrosine nitration induced by ONOO- in cultured murine fibroblasts as well as that induced by phorbol ester (PMA) in nitrite-supplemented human neutrophils, all three phenolics were also effective (100% and over 75% inhibition for fibroblasts and neutrophils, respectively, at 25 microM). This ability seems to be due to a direct interaction with ONOO- or with the species generated by leukocytes. The possible interference with the production of NO was also studied both DCA and EGCG inhibited nitrite production in LPS-stimulated macrophages by 24% and 40%, respectively, and the expression of nitric oxide synthase-2 (NOS-2), as well. DCA and EGCG reduced by 52% and 59%, respectively, the NF-kappaB transcriptional activity. In contrast, DCE did not show any effect. The assayed phenolics exert varying degrees of protection against the chemical modifications induced by RNS depending not only on the hydroxyl pattern, but also on the presence of bicarbonate.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ácido Quínico
/
Ácido Peroxinitroso
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Espécies Reativas de Nitrogênio
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Arch Biochem Biophys
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Espanha
País de publicação:
EEUU
/
ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
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EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
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US
/
USA